HK1183783B - Systems and methods for tissue ablation - Google Patents

Description

Systems and methods for tissue resection

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority of U.S. provisional patent application No.61/347,351 filed 5/21/2010, in accordance with 35u.s.c. § 119 (e); priority rights of U.S. provisional patent application No.61/357,886 filed on 23/6/2010; and U.S. provisional patent application No.61/357,894 filed on 23/6/2010, the entire contents of each of which are incorporated herein by reference.

Technical Field

The present invention relates generally to thermal ablation/ablation (ablation) systems and methods, and more particularly to Radio Frequency (RF) neurostimulation, such as spinal RF neurostimulation systems and methods.

Background

Thermal ablation involves generating a sufficient temperature change to produce necrosis in a particular tissue volume within the patient. The target volume may be, for example, a nerve or a tumor. A significant challenge in ablation therapy is to provide adequate treatment of the target tissue while sparing surrounding structures from damage.

RF ablation uses electrical energy delivered through an electrode to a target volume to generate heat in the region of the electrode tip. Radio waves are emitted from the non-insulated distal portion of the electrode tip. As current flows from the electrode tip into the earth, the introduced rf energy causes molecular strain or ion excitation in the region around the electrode. The resulting strain causes a temperature increase in the region around the electrode tip. RF neurostimulation uses RF energy to cauterize target nerves, thereby blocking the ability of the nerves to transmit pain signals to the brain.

Disclosure of Invention

This application describes example embodiments of devices and methods for tissue ablation, such as spinal radio-frequency denervation. The system includes a needle having an expandable filament capable of creating an asymmetric offset lesion in a target volume that may include a target nerve. Ablation of at least a portion of the target nerve may inhibit the ability of the nerve to transmit signals, such as pain signals, to the central nervous system. Offsetting the lesion may facilitate the procedure by directing energy toward the target nerve and away from indirect/accessory structures (colligative structures). Example anatomical structures include lumbar, thoracic and cervical medial nerve and branch tips/branches and sacroiliac joints.

In some embodiments, the needle includes an elongate member having a distal end, a tip coupled to the distal end of the elongate member, and a plurality of filaments. The tip includes a slope (a below to a point) to a point. The plurality of filaments are movable between a first position at least partially within the elongate member and a second position at least partially outside the elongate member. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode.

In some embodiments, the needle includes an elongate member having a distal end, a tip coupled to the distal end of the elongate member, and a plurality of filaments. The tip includes a sloped portion that includes a point on a side of the elongated member. The plurality of filaments are movable between a first position at least partially within the elongated member and a second position at least partially outside and adjacent to a side of the elongated member. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode.

In some embodiments, the needle includes an elongate member having a proximal end and a distal end, a tip coupled to the distal end of the elongate member, a plurality of filaments, and a filament deployment mechanism coupled to the proximal end of the elongate member. The tip includes a sloped portion that includes a point. The plurality of filaments are movable between a first position at least partially within the elongate member and a second position at least partially outside the elongate member. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode. The filament deployment mechanism includes an advancing hub, a rotating ring, and a main hub. The advancing hub includes a stem coupled to a plurality of filaments. The rotating ring comprises a helical guide. The stem of the advancing hub is at least partially inside the rotating ring. The main hub includes a stem including a helical thread configured to cooperate with the helical track. The stem of the main hub is at least partially inside the rotating ring. The stem of the advancing hub is at least partially inside the main hub. Upon rotation of the rotating ring, the filament is configured to move between a first position and a second position.

In some embodiments, the needle includes an elongate member having a distal end, a tip coupled to the distal end of the elongate member, and a plurality of filaments. The tip includes a point. The plurality of filaments are movable between a first position at least partially within the elongate member and a second position at least partially outside the elongate member. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode. The single wire includes a plurality of filaments.

In some embodiments, the needle includes an elongate member having a distal end, a tip coupled to the distal end of the elongate member, and a plurality of filaments. The tip includes a tilt to a point. The plurality of filaments are movable between a first position at least partially within the elongate member and a second position at least partially outside the elongate member. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode. The tip includes a stem at least partially within the elongated member. The stem includes a first filamentous cavity, a second filamentous cavity, and a third cavity. The angled portion includes a fluid port in fluid communication with the third cavity.

In some embodiments, the needle includes an elongate member having a proximal end and a distal end, a tip coupled to the distal end of the elongate member, a plurality of filaments, and a rotating deployment mechanism coupled to the proximal end of the elongate member. The tip includes a tilt to a point. The plurality of filaments are movable between a first position at least partially within the elongate member and a second position at least partially outside the elongate member. The deployment mechanism includes a marker that deploys a plurality of filaments relative to the tip segment. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode.

In some embodiments, the needle includes an elongate member having a distal end, a tip, and a plurality of filaments. The tip includes a first body portion and a second body portion. The first body portion includes a tapered portion and a point. The tapered portion includes a plurality of filament ports. The second body portion is coupled to the distal end of the tip. The second body portion is angled with respect to the first body portion. The plurality of filaments are movable between a first position at least partially at least one of the tip and the elongate member and a second position at least partially outside the filament port. The plurality of filaments and the tip are configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode.

In some embodiments, a method of heating an intervertebral disc comprises: positioning the distal end of the needle in the posterior annulus/ring (annuus); spreading the filaments of the needle; moving the posterior annulus from the outside to the inside; applying radio frequency energy to the tip and the filament; and, resecting the painful fibrous tissue in the posterior annulus.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member, an actuator interconnected to the plurality of filaments, and a lumen in the elongate member. The tip is shaped to pierce the tissue of the patient. Movement of the actuator relative to the hub moves the plurality of filaments relative to the tip. The lumen and tip are configured to receive an RF probe such that an electrode, tip, and first and second filars of the inserted RF probe are operable to form a single monopolar RF electrode.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. An actuator is operable to move the plurality of filaments between a retracted position and a fully deployed position relative to the hub, elongate member, and tip. In the fully deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the fully deployed position. Each point is distal to the distal end of the needle. The average position of all points is offset from the central longitudinal axis of the elongate member.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. Each point is on the same side of a plane containing the central longitudinal axis of the elongate member.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. The plurality of filaments consists of a first filament and a second filament, and the needle is free of filaments other than the first and second filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. In the deployed position, a midpoint between the distal end of the first filament and the distal end of the second filament is offset from the central longitudinal axis of the needle.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. The plurality of filaments consists of a first filament and a second filament, and the needle is free of filaments other than the first and second filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. In their respective deployed positions, each distal end defines a vertex of a polygon. The center of mass of the polygon is offset from the central longitudinal axis of the needle.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. The plurality of filaments consists of a first filament and a second filament, and the needle is free of filaments other than the first and second filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. In their respective deployed positions, each of the plurality of filaments points in at least a partial distal direction.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. The plurality of filaments consists of a first filament and a second filament, and the needle is free of filaments other than the first and second filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. When the plurality of filaments are in the deployed position, a portion of each filament extends outwardly away from the tip. Each portion of each filament extending outwardly away from the tip is straight.

In some embodiments, a needle for insertion into a patient during an RF ablation procedure includes a hub, an elongate member secured to the hub, a tip secured to the elongate member at a distal end of the needle, a plurality of filaments in at least a portion of the elongate member in a retracted position, and an actuator interconnected to the plurality of filaments. The plurality of filaments consists of a first filament and a second filament, and the needle is free of filaments other than the first and second filaments. An actuator is operable to move the plurality of filaments between a retracted position and a deployed position relative to the hub, the elongate member, and the tip. In the deployed position, the plurality of filaments extend outwardly and away from the tip. Each filament includes a distal end that defines a point in the deployed position. Each point is distal to the distal end of the needle. The tip includes an angle of at least 200 ° about a central longitudinal axis of the filaless elongate member when the plurality of filaments are in the deployed position.

In some embodiments, a method of performing spinal RF denervation in a patient comprises: moving the tip of the needle to a first position along the spine of the patient that is closest to the target nerve; after achieving the first position, advancing the plurality of filaments to a deployed position relative to the tip; and, after the advancing step, applying RF energy to the tip and the plurality of filaments, wherein the applying generates heat that ablates a portion of the target nerve.

In some embodiments, a method of performing lumbar RF denervation on a medial branch nerve of a patient comprises: moving the tip of the needle to a first position between the transverse and anterior processes of the lumbar spine such that the end point of the tip is closest to the surface of the vertebra; after achieving the first position, moving the plurality of filaments forward relative to the tip to a deployed position; and applying RF energy to the tip and the plurality of filaments after moving the plurality of filaments forward. The applying generates heat that ablates a portion of the medial branch nerve.

In some embodiments, a method of performing sacroiliac joint RF denervation in a patient comprises: a, moving the tip of the needle to a first position closest to the sacrum of the patient; b, moving the plurality of filaments forward relative to the tip to a deployed position; c, applying RF energy to the tip and the plurality of filaments, wherein the applying generates heat to ablate the first volume; d, retracting the plurality of filaments; e, rotating the lances about their central longitudinal axes with the tips in the first position to reorient the plurality of lances; f, moving the plurality of filaments forward relative to the tip; and g, reapplying RF energy to the tip and the plurality of filaments, wherein the reapplying comprises ablating a second volume adjacent to the tip, wherein a center of the first volume is offset from a center of the second volume.

In some embodiments, a method of performing thoracic RF denervation on a medial branch nerve of a patient comprises: moving the tip of the needle to a first position proximate the anterior surface of the transverse process of the thoracic vertebra such that the distal point of the tip is closest to the anterior surface; after achieving the first position, moving the plurality of filaments forward relative to the tip toward a vertebra directly on the thoracic vertebra to a deployed position; and applying RF energy to the tip and the plurality of filaments after moving the plurality of filaments forward, wherein the applying generates heat that ablates a portion of the medial branch nerve between the thoracic vertebra and a vertebra directly above the thoracic vertebra.

In some embodiments, a method of performing an RF denervation of an internal cervical branch on a third occipital nerve of a patient comprises: a, positioning a patient in a prone position; b, targeting a C2/3Z joint on one side; c, rotating the patient's head away from the target side; d, locating the lateral ligament (lateral aspect) of the C2/3Z joint; e, after steps a, b, C and d, moving the needle tip over the outermost ligament of the bone of the joint column of the C2/3Z joint to a first position contacting the bone of the most posterior and lateral ligaments closest to the Z-joint complex; f, after step e, retracting the tip of the needle from the first position by a predetermined distance; g, after step f, extending a plurality of filaments outward from the apex toward the lateral ligament of the C2/3Z joint to position the plurality of filaments straddling the lateral joint lucent area and behind the C2/3 neural foramen; h, after step g, verifying the position of the tip and the filament by imaging the tip and the surrounding volume; and i, after step h, applying RF energy to the tip and the plurality of filaments, wherein the applying generates heat that ablates a portion of the third occipital nerve.

For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment. Thus, for example, it will be appreciated by those skilled in the art that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

All such embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description having reference to the attached figures, the invention not being limited to any particular disclosed embodiment.

Drawings

These and other features, aspects, and advantages of the present disclosure are described with reference to drawings of certain embodiments, which are intended to illustrate certain embodiments and not to limit the present disclosure.

Fig. 1 shows a schematic diagram of an RF neurostimulation system being used to perform RF neurostimulation on a patient.

Fig. 2A shows a perspective view of an example embodiment of a needle that may be used in an RF denervation procedure.

FIG. 2B shows a cut-away perspective view of a portion of the lances of FIG. 2A.

Fig. 2C shows a partial cut-away and partial cross-sectional view of a portion of another example needle embodiment that may be used in an RF denervation procedure.

Fig. 2D illustrates a perspective view of another example embodiment of a needle that may be used in an RF denervation procedure.

Fig. 2E shows a perspective view of an example embodiment of a filament formed from a single wire (wire).

Figure 3A shows a detailed view of an example embodiment of a needle tip with the filament in a fully deployed position.

Figure 3B shows a detailed view of the needle tip of figure 3A with the filament in a retracted position.

Figure 3C shows a detailed view of another example embodiment of a needle tip with the filament in the deployed position.

Figure 3D illustrates a detailed view of another example embodiment of a needle tip with the filament in a fully deployed position.

Figure 3E shows a detailed view of the needle tip of figure 3D with the filament in a retracted position.

Figure 3F shows a cross-sectional view of the needle tip of figure 3D with the filament in a retracted position.

FIG. 3G shows a detailed view of yet another example embodiment of a needle tip with the filament in the deployed position.

Figures 3H and 3I show detailed views of yet other exemplary embodiments of the needle tip with the filament in the deployed position.

FIG. 4 shows a schematic diagram of an exemplary embodiment of an RF probe assembly.

Fig. 5 illustrates a proximal end view of an exemplary embodiment of a needle tip.

FIG. 6 illustrates a side view of an example embodiment of a needle tip.

FIG. 7 illustrates a proximal end view of another exemplary embodiment of a needle tip.

FIG. 8 illustrates a proximal end view of yet another exemplary embodiment of a needle tip.

FIG. 9 illustrates a proximal end view of yet another exemplary embodiment of a needle tip.

FIG. 10 illustrates a side view of another exemplary embodiment of a needle tip.

FIG. 11A shows a graphical representation of an example set of isotherms that may be produced by the needle of FIG. 2A.

FIG. 11B illustrates an example lesion map that may be produced by the needle of FIG. 2A.

FIG. 11C illustrates an exemplary damage map that may be produced by a monofilament needle.

Figure 12 shows a perspective view of the needle of figure 2A positioned relative to a lumbar spine for performing RF denervation.

Fig. 13 illustrates a sacral map including a target lesion volume for performing sacral joint (SIJ) RF neurosectomy.

Fig. 14 shows a perspective view of the needle of fig. 2A positioned relative to a thoracic vertebra for performing RF denervation.

FIG. 15 shows a perspective view of the needle of FIG. 2A positioned relative to the C2/3 cervical facet joint protrusion (z-joint) for performing a medial cervical branch RF denervation on the third occipital nerve.

Fig. 16A shows a perspective view of an example embodiment of a needle tip.

FIG. 16B shows a rear elevation view of the needle tip of FIG. 16A.

FIG. 16C shows a front elevation view of the needle tip of FIG. 16A.

Fig. 16D illustrates a perspective view of an example embodiment of an elongated member.

Fig. 16E shows a perspective view of the needle tip of fig. 16A and the elongate member of fig. 16D.

FIG. 16F shows a cross-sectional view of the needle tip and elongate member and filament and RF probe example embodiment of FIG. 16E along line 16F-16F of FIG. 16E.

Figure 16G illustrates a cross-sectional view of another exemplary embodiment of a needle tip and an elongate member and exemplary embodiments of a filament and an RF probe.

Fig. 17A shows an exploded view of the components of the deployment mechanism of fig. 2D.

Figure 17B illustrates a cross-sectional view of components of the deployment mechanism of figure 2D.

Fig. 17C shows a perspective view of the example embodiment of the advancing hub and wire of fig. 2E.

FIG. 17D illustrates a cross-sectional view of an example embodiment of a rotating ring.

Fig. 17E illustrates a cross-sectional view of the example embodiment of the main hub, taken along line 17E-17E of fig. 17B, and an exploded view of the example embodiment of the elongated member.

Figure 18A shows an axial view of the rear angled needle inlet.

FIG. 18B shows a sagittal view of the posterior oblique needle entry.

Detailed Description

While certain embodiments and examples are described below, it will be apparent to those of ordinary skill in the art that the invention extends beyond the specifically disclosed embodiments and/or uses and obvious modifications and equivalents thereof. Thus, the scope of the invention disclosed herein is not intended to be limited by any particular embodiment described below.

In the following description, the present invention is set forth in the context of instruments and methods for performing RF ablation. More specifically, RF denervation may be performed using a variety of systems and methods to ablate a portion of a target nerve. More specifically, spinal RF denervation may be performed using a variety of systems and methods to resect portions of a target nerve along a patient's spine to relieve pain. For example, embodiments of the methods and instruments described herein relate to lumbar RF denervation to resect the facet joint nerve between the L4 and L5 lumbar vertebrae. Denervation may be accomplished by applying RF energy to a portion of the medial branch nerve to ablate or cauterize a portion of the nerve, thereby blocking the ability of the nerve to transmit signals to the central nervous system. In another example, embodiments described herein relate to sacral joint RF neurosectomy.

Fig. 1 shows an example embodiment of a system 100 for performing RF denervation on a patient 101. The patient 101 may be positioned downward on a table or surface 109 to allow contact along the spine of the patient 101. Other patient orientations are possible depending on the procedure. The table top 109 may comprise a radiolucent material that is substantially transparent to X-rays, such as carbon fiber.

The system 100 can include an RF generator 102 capable of emitting RF energy signals sufficient to ablate target tissue (e.g., cause damage to a target volume; cauterize a target portion of a target nerve). The RF generator 102 may be capable of delivering, for example, about 1W to about 200W and about 460,000Hz to about 500,000Hz RF energy. The lances 103 capable of conducting (e.g., transmitting or directing) RF energy may be interconnected to the RF generator 102 and may be used to deliver RF energy signals to specific sites within the patient 101. In some embodiments where the needle 103 is a monopolar device, the return electrode pad 104 may be attached to the patient 101 to complete a circuit from the RF generator 102, through the needle 103, through a portion of the patient 101, through the return electrode pad 104, and back to the RF generator 102. In some embodiments including a bipolar arrangement, the lances 103 may include at least one supply electrode and at least one return electrode to define an electrical circuit.

The RF generator 102 may be operable to control the RF energy emitted by the lances 103 in a closed loop manner. For example, the needle 103 and/or the RF probe in the needle 103 may include a temperature measurement device, such as a thermocouple, configured to measure the temperature at the target tissue. Data, such as power levels and/or impedances, may also be obtained from the RF generator 102, which may also be used for closed loop control of the lances 103. For example, once the temperature is detected, parameters of the RF generator 102 (e.g., frequency, wattage, duration of application) may be automatically adjusted.

FIG. 4 illustrates an example RF probe assembly 400 that is compatible with the lances 103. The RF probe assembly 400 includes an RF probe 401 that can be inserted into a patient (e.g., through the needle 103) and can direct RF energy to target tissue. In some embodiments, RF probe 401 may be in electrical communication with needle 103 to direct RF energy to target tissue, but not to insert it into the patient. The RF probe 401 may include a thermocouple operable to measure the temperature at the distal end 402 of the RF probe 401. The RF probe assembly 400 may include a connector 403 and a cable 404 configured to connect the RF probe 401 to an RF generator (e.g., the RF generator 102).

Returning to fig. 1, the system 100 optionally includes an imaging system 105 capable of generating internal images of the patient 101 and the needle 103, for example, to facilitate navigation of the needle 103 during a procedure. The system 100 may further include a display device for displaying the generated image to a user executing the program. In some embodiments, the imaging system 105 includes a fluoroscope that is capable of producing real-time two-dimensional images of the needle 103 and the internal structure of the patient 101. In certain such embodiments, the imaging system includes an X-ray source 106, an X-ray detector 107, and a controller 108 in electrical communication with the X-ray source 106 and/or the X-ray detector 107. The X-ray source 106 and X-ray detector 107 may be mounted on a movable structure (e.g., a C-arm) to facilitate capturing multiple images of the patient 101 (e.g., at various angles or projection views). Other imaging systems 105 (e.g., Computed Tomography (CT) scanners) are also possible.

Fig. 2A illustrates an example embodiment of a needle 103 that may be used in the system 100 for performing RF denervation. The needle 103 includes a tip 201 that tapers to a point 301 capable of penetrating the skin of a patient. In some embodiments, the tip point tapers to a point substantially at the center of the tip 201 (e.g., a "pencil point" tip). In some embodiments, the tip point tapers to a point substantially to one side of the tip 201 (e.g., "cut" or "angled" or "lancet" or "Queenk" tip). The needle 103 further comprises an elongate member 203 connected to a tip 201 at a distal end 202 of the needle 103 and to a hub 204 at a proximal end 205 of the needle 103. The needle 103 includes a longitudinal axis 223 along the center of the elongated member 203.

Fig. 2D illustrates another example embodiment of a needle 103 that may be used in the system 100 for performing RF denervation. The needle 103 includes a tip 211 that tapers to a point 301 capable of penetrating the skin of a patient. In some embodiments, the tip point tapers to a point substantially at the center of the tip 211 (e.g., a "pen point" tip). In some embodiments, the tip point tapers to a point substantially to one side of the tip 211 (e.g., "cut" or "angled" or "lancet" or "Queenk" tip). The needle 103 further comprises an elongate member 203 connected to a tip 211 at the distal end 202 of the needle 103 and to a hub 204 at the proximal end 205 of the needle 103. The needle 103 includes a longitudinal axis 223 along the center of the elongated member 203.

The needle 103 may include a self-contained mechanical mechanism in the form of deployable filaments 206a, 206b operable to expand the effective RF energy delivery volume as compared to known single electrode RF probes. The filaments 206a, 206b may be at least partially within the elongate member 203 and may be operable to emerge through the aperture of one or more needles 103 proximate the distal end 202 of the needle 103. In some embodiments, the needle 103 comprises a single filament or three or more filaments. The filaments 206a, 206b allow for contraction/expansion, deflection, and/or tailoring of the effective RF energy delivery over a selected anatomical region to tailor the profile of the lesion created using the needle 103 to match a desired target volume (e.g., spherical, hemispherical, planar, spherical, kidney-shaped, mitten-shaped, oval, snowman-shaped, etc.). The filaments 206a, 206b may be deployed and/or retracted by moving (e.g., rotating) the actuator 216 relative to the hub 204.

As will be further described, the needle 103 may further include a tubular body 207 including a cavity 222 therethrough. The cavity 222 may be used to transfer fluid to and/or from a target volume. The cavity 222 may also receive an RF probe 401 for delivering RF energy to a target volume. The cavity 222 may also receive a virtual or temporary probe, for example, to occlude the fluid port 210 during insertion. In some embodiments, RF probe 401 is integrated with needle 103. In certain such embodiments, tubular body 207 need not be provided for RF energy transfer, although tubular body 207 may be included to facilitate fluid transfer. In some embodiments, the filaments 206a, 206b include a lumen therethrough for delivering fluid to and/or from a target volume. In some embodiments, the filaments 206a, 206b do not include a lumen therethrough (e.g., are solid). The filaments 206a, 206b may function as thermocouples.

As the RF energy penetrates biological tissue, proteins and water molecules oscillate in response to the RF current, and the tissue adjacent the RF electrode heats up. As the tissue heats up and coagulates, the biological properties of the tissue change. These tissue changes limit the penetration of RF energy beyond the leading edge defined by the shape and size of the active needle tip. Thus, the size of the radiofrequency lesion using conventional single needle technology is particularly limited after a certain time of achieving a certain temperature delivery.

The needle 103 with the filaments 206a, 206b can overcome this obstacle and expand the effective area of RF energy delivery by providing multiple locations from which RF energy is emitted (e.g., the tips 201, 211 of the filaments 206a and/or 206 b). The multiple filars 206a, 206b are used to provide additional conduits for RF energy that produce a multi-electrode RF field effect. The size, shape, and location of the lesion created by the needle 103 may be determined, at least in part, by parameters such as the number, angle, length, position, and/or orientation of the filaments, as well as RF energy parameters such as wattage, frequency, and/or duration of application, one or both of which may be advantageously varied by varying various aspects of the filaments, as described below, to suit a particular anatomical application.

Where it is desired to offset a lesion from central longitudinal axis 223, the lesion can be offset in the desired direction from central longitudinal axis 223 by rotationally orienting needle 103. The lances 103 may be used to create lesions that are offset from the central longitudinal axis 223 in a first direction. The filaments 206a, 206b may be retracted (e.g., after creating the first lesion), the needle 103 rotated, and the filaments 206a, 206b re-expanded to create a lesion offset from the central longitudinal axis 223 in a second direction (e.g., creating a second lesion).

Fig. 3A and 3B show detailed views of an example embodiment of the distal end 202 of the needle 103 including the tip 201. The tip 201 may include a sharp point 301 (e.g., a point that tapers to be substantially in the center of the tip 201, a pencil point tip) for piercing the skin of a patient and facilitating passage through tissue. The tip 201 may include a tapered portion 302 that transitions the tip 201 from a point 301 to a body portion 303. The body portion 303 is the portion of the tip 201 that is closest to the tapered portion 302. The body portion 303 may be cylindrical, as shown, or may be other suitable shapes. The body portion 303 may have a cross-section that conforms to (e.g., is coaxial with) the cross-section of the elongate member 203.

Fig. 3D and 3E show detailed views of an example embodiment of the distal end 202 of the needle 103 including the tip 211. The tip 201 may include a sharp point 301 (e.g., a point that tapers to substantially one side of the tip 201, a cut or beveled or lancet or a Quicker tip) for piercing the skin of a patient and facilitating passage through tissue. The tip 211 may include a tapered portion 302 that transitions the tip 201 from the point 301 to a body portion 303. The body portion 303 is the portion of the tip 201 that is closest to the tapered portion 302. The body portion 303 may be cylindrical, as shown, or may be other suitable shapes (e.g., as shown in fig. 16A). The body portion 303 may have a cross-section that conforms to (e.g., is coaxial with) the cross-section of the elongate member 203. In some embodiments, the tip 211 has a bevel angle that is between about 10 ° to about 45 °, between about 15 ° to about 35 °, between about 20 ° to about 30 ° (e.g., about 25 °), combinations thereof, and the like. Other angles of inclination are also possible. In some embodiments, point 301 has an angle between about 40 ° and about 120 °, about 70 ° and about 90 °, about 75 ° and about 85 ° (e.g., about 79 °), combinations thereof, and the like. Other angles are also possible.

The tips 201, 211 or non-insulated portions thereof may function as RF energy delivery elements. The tips 201, 211 may comprise (e.g., be made of) a conductive material, such as stainless steel (e.g., 300 series stainless steel). The tips 201, 211 may be at least partially coated (e.g., with an insulator). The material of the tips 201, 211 and the material of the optional coating may be selected, for example, to act as an insulator, to improve radiopacity, to improve and/or modify RF energy conduction, to improve smoothness, and/or to reduce tissue adhesion.

The tip 201, 211 includes a first filament port or slot 304a (not visible in fig. 3A, 3B, 3D, and 3E) and a second filament port or slot 304B. The profile of the filament slots 304a, 304b may be selected to allow the filaments 206a, 206b to be properly retracted when the needle 103 is inserted into the body (e.g., as shown in fig. 3F so that the filaments 206a, 206b are within the cross-sectional envelope of the body portion 303 of the tips 201, 211) so that the filaments 206a, 206b do not cause any inadvertent damage to the patient. This positioning of the filament slots 304a, 304b avoids having a filament exit feature at the tapered location 302 and thus avoids potential coring that would result from this positioning.

The internal profile of the filament slots 304a, 304b may be designed so that the filaments 206a, 206b may be easily retracted and advanced. For example, the internal profile of the filament slots 304a, 304b may include a transition region 305 that intersects the exterior surface of the body portion 303 at an angle of about 30 °. For example, the transition region 305 may be curved and/or planar. Advancement of the filaments 206a, 206b without a preset bias/bias (e.g., substantially straight) relative to the filament slots 304a, 304b can result in outward deflection of the filaments 206a, 206b as the filaments 206a, 206b move distally along the transition region 305. Depending on the positioning of the transition region 305 relative to the location defining the filaments 206a, 206b (e.g., in the needle 103 of fig. 3A, the filaments 206a, 206b are limited to longitudinal movement in which they enter the elongate member 203) and depending on the mechanical properties of the filaments 206a, 206b, various angles of deployment of the filaments 206a, 206b relative to the central longitudinal axis 223 may be achieved. In general, the portions of the filaments 206a, 206b that extend outwardly away from the filament slots 304a, 304b may not be limited, and thus may take any suitable form. For example, in the absence of a preset bias, such as shown in fig. 2A, 3C, 3D, 6, 11A-11C, and 14, the portion of the filament extending outward away from the filament slots 304a, 304b (and thus away from the tip) may be substantially straight. As another example, the portion of the filament extending outward away from the filament slot may take any suitable shape when the preset bias is present, such as the curved shape in fig. 10.

The radial orientation of the filament slots 304a, 304b may be selected such that a center point between the filament slots 304a, 304b does not coincide with (e.g., is not coaxial with) the central longitudinal axis 223. For example, as shown in fig. 2A, 3B, 3D, and 3E, the filament slots 304a, 304B may be positioned such that they are about 120 ° apart around the circumference of the tips 201, 211. Other filament slot configurations may be configured to achieve the filament arrangements described below. For example, the filament slots 304a, 304b can be spaced about 45 ° to about 180 ° apart around the circumference of the tips 201, 211, about 90 ° to about 150 ° apart around the circumference of the tips 201, 211, combinations thereof, and so forth. Other angles are also possible. These configurations may also be achieved, for example, by varying the number of filament slots, the arrangement of filament slots around the circumference of the tips 201, 211, and/or the arrangement of filament slots along the central longitudinal axis 223 to achieve the filament arrangements described below.

As described herein, and as shown in fig. 3A and 3B, the needle 103 can include a tubular body 207 including a lumen 222 therethrough. The lumen 222 may be used to receive an RF probe 401 to transmit RF energy, transmit fluid, and/or occlude the fluid port 210. The tips 201, 211 may include a fluid port 210 that may be in fluid communication with the cavity 222 via a passage through the tips 201, 211. In certain embodiments, the cavity 222 is a multi-purpose cavity capable of allowing injection of fluids and capable of receiving the distal end 402 of the RF probe 401 to deliver RF energy to the tip 201, 211, the filament 206a, and/or the filament 206 b. In some embodiments, fluid port 210 is longitudinally spaced from tip 301 (e.g., about 1mm to about 3mm apart). The fluid port 210 may be centrally located (e.g., as shown in fig. 3D), or it may be located offset from the central longitudinal axis 223 (e.g., as shown in fig. 2A and 3A). The fluid port 210 may be used to transfer fluid between the area of the tips 201, 211 and the proximal end 205 of the needle 103. For example, during an RF denervation procedure, anesthesia and/or imaging enhancement dyes may be introduced into the tissue region surrounding the tips 201, 211 through the fluid port 210. In some embodiments, the fluid port 210 is positioned along the tapered portion 302 of the tip 201, 211 (e.g., as shown in fig. 3A and 3D). In some embodiments, the fluid port 210 is located along the body portion 303 of the tip 201, 211.

Fig. 16A shows a perspective view of an example embodiment of a needle tip 211. In some embodiments, needle 103 does not include tubular body 207, but elongate member 203 includes cavity 308 therethrough, and tip 211 includes cavity 306c therethrough. Lumen 308 and lumen 306c may be used to receive RF probe 401 for delivering RF energy, for delivering fluid, and/or for occluding fluid port 210. In certain embodiments, the cavity 308 and the cavity 306c are multi-purpose cavities that can allow for injection of fluids and can receive the distal end 402 of the RF probe 401 to deliver RF energy to the tip 211, the filament 206a, and/or the filament 206 b. The filamentary lumens 306a, 306b may also allow for the transfer of fluid from the proximal end of the needle to the filament ports 304a, 304 b.

In some embodiments, the filamentary cavities 306a, 306b are sized to inhibit jamming and/or bending of the filaments in the tip 211. In some embodiments, the elongate member 203 can also include a filamentous cavity (e.g., including a tubular body in the elongate member 203). In some embodiments, the filamentous cavity in the elongate member 203 may be formed by an inner member (not shown) that extends at least part of the length of the elongate member 203. For example, the transverse cross-section of the inner member may have the same cross-section as the tip 211 portion shown in fig. 3F, which includes a channel in which a filament may be placed, and a lumen through which fluid, RF probe 401, and/or a virtual probe pass.

Fig. 16B shows a rear elevation view of the needle tip 211 of fig. 16A. Fig. 16C shows a front elevation view of the needle tip 211 of fig. 16A. The needle tip 211 includes: a filament lumen 306a in fluid communication with filament slot 304a and terminating at filament slot 304 a; a filament cavity 306b in fluid communication with filament slot 304b and terminating at filament slot 304 b; and a cavity 306 c. In some embodiments, the cavities 306a, 306b are spaced about 120 ° apart along the circumference of the tip 211. Other angles are also possible. In some embodiments, the cavity 306c is spaced about 120 ° from each cavity 306a, 306b along the circumference of the tip 211. Other angles are also possible. Referring back to fig. 3F, the filament 206a may be in the filament cavity 306a and the filament 206b may be in the filament cavity 306 b. The cavity 306c is in fluid communication with the fluid port 210. In some embodiments, as shown in fig. 16A, the proximal end of the tip 211 includes a tapered surface. When the filaments 206a, 206b are in the filamentary cavities 306a, 306b, the tapered surfaces may help guide the insertion of the RF probe 401 into the cavity 306 c. In some embodiments, the tapered surface has an angle that intersects (normal to) the tip 211 at an angle of about 15 ° to about 75 °, about 30 ° to about 60 °, about 40 ° to about 50 ° (e.g., about 45 °), combinations thereof, and the like. Other angles are also possible.

Fig. 16D illustrates a perspective view of an example embodiment of an elongated member 203. Elongate member 203 includes lumen 308, filament slot 304a, and filament slot 304 b. In some embodiments, the filament slots 304a, 304b are spaced about 120 ° apart along the circumference of the elongate member 203. Fig. 16E shows a perspective view of the elongate member 203 of fig. 16D and the needle tip 211 of fig. 16A. As described herein, the elongated member 203 may be coupled to the tip 211 by conductive epoxy bonding, welding, soldering, combinations thereof, and the like. The proximal portion of the tip 211 can be inserted into the cavity 308 of the elongate member 203. The filament slot 304b of the elongate member 203 is substantially aligned with the cavity 306b of the tip 211, allowing the filament 206b to deploy out of the cavity 306 b. Although not shown, the filament slot 304a of the elongate member 203 is substantially aligned with the cavity 306a of the tip 211, allowing the filament 206a to deploy out of the cavity 306 a. In some embodiments, each filament slot 304a, 304b has a length of about 0.025 inches to about 0.2 inches (approximately about 0.6mm to about 3 mm), about 0.05 inches to about 0.15 inches (approximately about 1.3mm to about 3.8 mm), about 0.075 inches to about 0.125 inches (approximately about 1.9mm to about 3.2 mm) (e.g., about 0.105 inches (approximately about 2.7 mm)), combinations thereof, and the like. Other lengths are also possible. In some embodiments, each filament slot 304a, 304b has a width of about 0.01 inches to about 0.4 inches (approximately about 0.25mm to about 10 mm), about 0.02 inches to about 0.03 inches (approximately about 0.5mm to about 0.76 mm), about 0.015 inches to about 0.025 inches (approximately about 0.38mm to about 0.64 mm) (e.g., about 0.02 inches (approximately about 0.5 mm)), combinations thereof, and the like. Other widths are also possible. In some embodiments, each transition region 305 has a length of about 0.02 inches to about 0.2 inches (approximately about 0.5mm to about 5 mm), about 0.05 inches to about 0.15 inches (approximately about 1.3mm to about 3.8 mm), about 0.075 inches to about 0.125 inches (approximately about 1.9mm to about 3.2 mm) (e.g., about 0.104 inches (approximately about 2.6 mm)), combinations thereof, and the like. Other lengths are also possible. In some embodiments where the transition regions comprise curved surfaces, each transition region 305 has a radius of curvature of about 0.01 inches to about 0.4 inches (approximately about 0.25mm to about 10 mm), about 0.15 inches to about 0.35 inches (approximately about 3.8mm to about 8.9 mm), about 0.2 inches to about 0.3 inches (approximately about 5mm to about 7.6 mm) (e.g., about 0.25 inches (approximately about 6.4 mm)), combinations thereof, and the like. Other radii of curvature are also possible. The particular combination of the dimensions of the transition region 305 and the filament slots 304a, 304b described herein may result in the deployment of the filaments 206a, 206b at a desired angle (e.g., about 30 °).

The cavity 308 is not visible in fig. 16E because the elongated member 203 covers the cavity 308. Covering the cavity 308 causes fluid inserted into the cavity 308 to exit the fluid port 210 and possibly the filament slots 304a, 304 b. In some embodiments, such as shown in fig. 3A and 3B, elongate member 203 can also include a slot that is closest to tubular body 207. In some such embodiments, tubular body 207 may extend distally of the slot (extended digital to the slot) and substantially all of the fluid inserted into lumen 222 may exit fluid port 210.

In the embodiment shown in fig. 16E, the body portion 303 of the tip 211 and the elongate member 203, except for the sleeve 307, both have substantially equal diameters, for example, to provide a smooth transition between the tip 211 and the elongate member 203. In some embodiments, the elongated member 203 can have an inner diameter of about 0.01 inches to about 0.04 inches (approximately about 0.25mm to about 1 mm), about 0.015 inches to about 0.035 inches (approximately about 0.38mm to about 0.89 mm), about 0.02 inches to about 0.03 inches (approximately about 0.5mm to about 0.76 mm) (e.g., about 0.025 inches (approximately about 0.64 mm)), combinations thereof, and the like. Other diameters are also possible. In some embodiments, the elongated member 203 has an outer diameter of about 0.01 inches to about 0.05 inches (approximately about 0.25mm to about 1.3 mm), about 0.02 inches to about 0.04 inches (approximately about 0.5mm to about 1 mm), about 0.025 inches to about 0.035 inches (approximately about 0.64mm to about 0.89 mm) (e.g., about 0.029 inches (approximately about 0.74 mm)), combinations thereof, and the like. Other diameters are also possible. In some embodiments, the proximal portion of the tip has an outer diameter of about 0.01 inch to about 0.04 inch (approximately about 0.25mm to about 1 mm), about 0.015 inch to about 0.035 inch (approximately about 0.38mm to about 0.89 mm), about 0.02 inch to about 0.03 inch (approximately about 0.5mm to about 0.76 mm) (e.g., about 0.025 inch (approximately about 0.64 mm)), combinations thereof, and the like. Other diameters are also possible. In some embodiments, tip 211 has an outer diameter of about 0.01 inch to about 0.05 inch (approximately about 0.25mm to about 1.3 mm), about 0.02 inch to about 0.04 inch (approximately about 0.5mm to about 1 mm), about 0.025 inch to about 0.035 inch (approximately about 0.64mm to about 0.89 mm) (e.g., about 0.029 inch (approximately about 0.74 mm)), combinations thereof, and the like. Other diameters are also possible.

Fig. 16F shows a cross-sectional view of the needle tip 211 and the elongate member 203 along line 16F-16F of fig. 16E. Fig. 16F also shows an example embodiment of the filament 206a and RF probe 401 in cavity 308, with the filament 206a in cavity 308 and cavity 306a, and then exiting through filament slot 304 a. In some embodiments, the elongate member 203 and the tip 211 comprise (e.g., are each made of) a conductive material (e.g., 300 series stainless steel) and are capable of conducting electrical signals from the RF probe 401 to the tip 211 and the filars 206a, 206b (e.g., due to physical contact of the conductive components) to form a monopolar electrode. In some embodiments, the RF probe 401, the filars 206a, 206b, the tip 211, and/or the elongate member 203 may include features configured to improve physical contact between components. The cross-sectional view shows cavity 308 in fluid communication with cavity 306c and fluid port 210.

Fig. 16G illustrates another cross-sectional view of an example embodiment of the needle tip 211 and the elongate member 203 similar to the lines along lines 16F-16F of fig. 16E. The tip 211 in fig. 16G does not include the fluid port 210, but fluid is able to exit the filament slots 304a, 304b because the filament slots are in fluid communication with the cavity 308. In some embodiments, the tip 211 includes a cavity 306c, e.g., to ensure placement or contact of the probe 401 (e.g., as shown in fig. 16G). In some embodiments, the tip 211 does not include the cavity 306c, for example, to reduce manufacturing costs when cutting the cavity 306c from a solid tip stem.

It should be appreciated that the passage through the tips 201, 211 may be sized to accommodate the tip of the RF probe 401, which may be inserted into the lances 103. The channel may be sized to satisfactorily transfer RF energy from the inserted RF probe 401 from the RF probe 401 to the tip 201, 211, filament 206a, and/or filament 206 b.

Fig. 3C and 3G each show a detailed view of the distal end 310 of the lances 309 as an alternative embodiment of the lances 103. Distal end 310 includes tips 311, 321, which may include sharpened tips 312, for piercing the skin of a patient and facilitating advancement through tissue. The tip 311, 321 may include a tapered portion 313 that tapers the tip 311, 321 from a point 312 to the first body portion 314. The first body portion 314 may be connected to the second body portion 315 at an angle 316. In some embodiments, angle 316 is about 15 °. Other angles 316 are possible. For example, the angle 316 may be about 5 ° to about 90 °, about 10 ° to about 60 °, about 10 ° to about 45 °, about 10 ° to about 20 °, combinations thereof, and the like. Other angles are also possible. The second body portion 315 may be aligned with the elongated member 317. The elongated member 317 may be configured similar to the elongated member 203 of fig. 3A, 3B, 3C, and 3D. The angle 316 between the first and second body portions 314, 315 may assist the user in navigating the lances 309 to a desired position. For example, by rotating the lances 309 so that the first body portion 314 points in a desired direction, subsequent advancement of the lances 309 may cause the lances 309 to advance along a non-straight path that is biased in the desired direction.

The first and second body portions 314, 315 may be cylindrical, as shown, or they may be any other suitable shape. The first and second body portions 314, 315 can have a cross-section that conforms to (i.e., is coaxial with) the cross-section of the elongate member 317.

The tips 311, 321 or uninsulated portions thereof may function as RF energy transfer elements. The tips 311, 321 may comprise (e.g., be made of) a conductive material, such as stainless steel (e.g., 300 series stainless steel). The tips 311, 321 may be coated (e.g., with an insulator). The material of the tips 311, 321 and optionally the coating can be selected, for example, to act as an insulator, to improve radiopacity, to improve and/or modify RF energy conduction, to improve smoothness, and/or to reduce tissue adhesion.

The filaments 319a, 319b may also function as RF energy delivery elements. The filars 319a, 319b may be constructed in a similar manner as described with respect to the filars 206a, 206 b.

The tip 311 of fig. 3C includes a filament slot 318a and a filament slot 318 b. The profile of the filament slots 318a, 318b may be selected to allow the filaments 319a, 319b to be properly retracted (e.g., they are in a cross-sectional envelope of the second body portion 315) when the needle 309 is inserted into the body so that the filaments 319a, 319b do not cause any inadvertent damage to the patient (e.g., by following the second body portion 315). This positioning of filament slots 318a, 318b avoids having filament exit features on the tapered portion 313 and the first body portion 314, which can avoid potential coring. The internal profile of the filament slots 318a, 318b may include a transition region that intersects the exterior surface of the second body portion 315 at an angle, and advancement of the filaments 319a, 319b relative to the filament slots 318a, 318b without a preset bias (e.g., substantially straight) can result in outward deflection of the filaments 319a, 319b as the filaments 319a, 319b move distally along the transition region.

The configuration and orientation of the filament slots 318a, 318b may be selected so that deployment of the filaments 319a, 319b may achieve the positioning shown in fig. 3C. In fig. 3C, the filaments 319a, 319b lie generally in a plane that is perpendicular to a plane that includes the angle 316 between the first and second body portions 314, 315. As shown, the filaments 319a, 319b can be positioned such that they extend at an angle (e.g., about 15 °, about 10 ° to about 90 °, about 10 ° to about 60 °, about 10 ° to about 45 °, about 10 ° to about 20 °, combinations thereof, and so forth) relative to a plane that includes the angle 316. Other angles are also possible. Other filament slot 318a, 318b configurations may be configured to achieve other desired filament 319a, 319b arrangements. These configurations may be achieved, for example, by varying the number of filament slots and filaments, the arrangement of filament slots around the circumference of the tip 311, the angle at which the filaments extend away from the first and second body portions 314, 315, and/or the arrangement of filament slots along the first and second body portions 314, 315.

Fig. 3G illustrates an example embodiment of a tip 321 that includes a filament slot 318a and a filament slot 318b along the first body portion 314. The profile of the filament slots 318a, 318b may be selected to allow the filaments 319a, 319b to be properly retracted (e.g., so that they are in the cross-sectional envelope of the second body portion 315) when the needle 309 is inserted into the body so that the filaments 319a, 319b do not cause any inadvertent damage to the patient. The positioning of the filament slots 318a, 318b along the first body portion 314 can potentially result in coring, so the filaments 319a, 319b can be configured to substantially occlude the filament slots 318a, 318b that can avoid potential coring. The internal profile of the filament slots 318a, 318b may lack a transition region, and advancement of the filaments 319a, 319b without a pre-set bias (e.g., substantially straight) due to being located on the first body portion 314 can result in the filaments 319a, 319b continuing to advance substantially straight (e.g., along the longitudinal axis of the elongate member 317 and/or the second body portion 315) as the filaments move distally out of the filament slots 318a, 318 b. Although not shown, there may also be an arrangement of filament slots along the tapered portion 313 (e.g., the filament continues to advance along the longitudinal axis of the first body portion 314). Although not shown, the embodiment shown in fig. 3A and 3D may be altered so that the filaments 206a, 206b exit along the tapered portion 302.

The lances 309 may comprise tubular bodies comprising lumens therethrough, such as described herein with respect to fig. 3A, 3B, 3D, and 3E. The cavity may be for receiving an RF probe for delivering RF energy and/or for transmitting a fluid. In this regard, the tip 311 may also include a fluid port 320 that may be in fluid communication with the cavity via a passage through the tip 311. Fluid port 320 is used to transfer fluid between the region of tip 311 and the proximal end of needle 309.

In the deployed position shown in fig. 3C, the distal ends of the filaments 319a, 319b are disposed distal to the point 312. In the deployed position shown in fig. 3G, the distal ends of the filaments 319a, 319b are disposed distal to the point 312. In the retracted position (not shown, but similar to that shown in fig. 3B and 3E), the distal ends of the filaments 319a, 319B are entirely within the outer perimeter of the tips 311, 321 (e.g., where the second body portions 315 of the tips 311, 321 are circular perimeters). In the deployed position, filaments 319a, 319b act as a broadcast antenna for an RF probe inserted into needle 309. The tip 311 or 321, filament 319a, and/or filament 319b may form a monopolar electrode for applying RF energy to the target volume. The filars 319a, 319b can allow the RF energy from the RF probe to spread over a larger volume than would exist through the tips 311, 321 alone.

In general, any or all of the variations herein may be incorporated into a particular embodiment of a needle to create a needle capable of creating lesions in a particular size, location and shape relative to the needle tip. These custom sizes, locations and shapes may be designed for a particular program. For example, a particular lesion size, location, and shape may be selected so that a user can navigate the needle to a particular landmark (e.g., nearest or touching a bone visible using fluoroscopy), and then orient the needle so that the deployed filament will be operable to create a lesion at a particular location relative to the landmark. By navigating to a particular internal demarcation, more accurate and/or consistent positioning of the spicules may be achieved, as opposed to attempting to visualize the relative position of the spicules of the offset demarcations. In this regard, the level of skill required to align the position determination lances for a particular procedure may be reduced.

Lesion shapes achievable by selection of variants herein may include, for example, generally spherical, elliptical, conical, and pyramidal. The orientation of the tip relative to this shape and the offset from the tip are selectable. In an embodiment, the tip of the deployed filament may be positioned distally relative to the tip point to provide easy location of the lesion relative to the tip. This capability may allow the needle to be inserted directly toward the target volume. In other embodiments, the tip of the deployed filament may be located at the same axial position along the central longitudinal axis, as the tip point(s) of the deployed filament may be located proximally relative to the tip point. In other embodiments, some filament end points may be located distal to the tip point, while other end points may be located proximal to the tip point.

The elongate member 203 may be in the form of a hollow tube (e.g., sheath, cannula) that interconnects the tips 201, 211 and the hub 204. The elongate member 203 may be configured with suitable strength to allow the needle 103 to pierce the patient's skin and be advanced through various tissue types, including, for example, adipose and muscular tissue, to a target area. The elongate member 203 may also be capable of resisting kinking as it advances. In some embodiments, the elongate member 203 comprises a rod having multiple lumens along its length to accommodate the filaments 206a, 206b, the RF probe 401, and/or the fluid channel.

The elongate member 203 receives portions of the filaments 206a, 206b and the tubular body 207 and allows relative movement of the filaments 206a, 206 b. The elongate member 203 may have any suitable size and internal configuration to allow insertion into a patient and to accommodate components therein. In some embodiments, the elongated member 203 is a 16gauge round tube or smaller. For example, the elongate member 203 may be 18gauge or 20 gauge. In some embodiments, the elongated member 203 has a maximum cross-sectional dimension of about 1.7 mm. In some embodiments, the elongated member 203 has a maximum cross-sectional dimension of about 1 mm. The elongated member 203 may have a length selected for performing a particular spinal RF denervation procedure on a particular patient. In some embodiments, elongate member 203 has a length of about 10 cm.

In certain embodiments, the elongate member 203 comprises (e.g., is constructed from) an insulating material to reduce (e.g., eliminate) the amount of RF energy emitted along the length of the elongate member 203 when the RF probe 401 is disposed therein. For example, the elongate member 203 may comprise (e.g., be constructed from) a polymer, ceramic, and/or other insulating material. In certain embodiments, the elongate member 203 includes an insulating coating or sleeve 307 (fig. 2D and 16D). In some embodiments, the elongate member is insulated (e.g., constructed of an insulating material and/or having an insulating coating 307) except for a distal end having a length of about 5mm to about 10 mm. Fig. 3H illustrates an example embodiment of a lance 309, which includes: an insulating coating 330 covering a proximal portion of the tip 321; and a coating 332a, 332b covering a proximal portion of the filaments 319a, 319 b. The coating 330 particularly insulates the bent region between the first and second body portions 314, 315 of the tip 321.

In some embodiments, the elongate member is insulated (e.g., constructed of an insulating material and/or having an insulating coating) except for the proximal portion. FIG. 3I illustrates an exemplary embodiment of a lance 309, which includes: an insulating coating 330 covering the distal portion of the tip 321; and a coating 332a, 332b covering a distal portion of the filaments 319a, 319 b. In some embodiments, in which is a distal portion of tip 321, needle 309 may create a kidney-shaped or mitten-shaped lesion, which may be due, for example, to the excision of tissue in which the active tip is pressed against a wall of a structure while the device is held within a lumen of the structure. For example, when ablating an intracardiac lesion where the device approaches the target through the ventricle, the insulation of the distal portion of the tip 321 held within the ventricle makes the biophysical indicator of the lesion (e.g., impedance, power, heat) more accurate because the insulated distal portion of the tip 321 surrounded by blood within the ventricle will not be a partial region.

Fig. 3H and 3I illustrate an insulated portion of the tip 321 and an exemplary embodiment of the filars 319a, 319b shown in fig. 3G. The component parts of the distal end of the other needle tips described herein may also be insulated (e.g., those parts shown in fig. 3A, 3C, and 3D). In some embodiments, only a portion of the tip 321 is insulated, and not a portion of the filars 319a, 319 b. In some embodiments, only portions of the filars 319a, 319b are insulated, not portions of the tip 321. In some embodiments, the distal portion of the tip 321 is insulated (e.g., shown in fig. 3I) and the proximal portions of the filaments 319a, 319b are insulated (e.g., shown in fig. 3H). In some embodiments, the distal portions of the filaments 319a, 319b are insulated (e.g., as shown in fig. 3I) and the proximal portion of the tip 321 is insulated (e.g., as shown in fig. 3H). In some embodiments, the insulating coating or sleeve 330, 332a, 332b may be adjusted. For example, one or all of the sleeves 330, 332a, 332b may be advanced or retracted relative to the tip 321, the filament 319a, and the filament 319b to increase or decrease the amount of conductive area exposed.

The elongate member 203 may include a coating that may increase radiopacity to aid in visualization of the location of the needle 103 using fluoroscopy. Elongate member 203 may include a lubricious coating to improve its ability to be inserted and positioned within a patient and/or to reduce tissue adhesion. The elongate member 203 may include markings 224 along its length to help determine the depth to which the needle 103 has entered the anatomy. The markers 224 may be radiopaque so that they can be viewed under fluoroscopy. A collar (not shown) may be disposed about elongate member 203 to aid in the placement of tips 201, 211 of lances 103. For example, the tips 201, 211 may be in a first position, then the collar may be placed against the patient's skin, and then the needle 103 may be advanced and/or retracted a particular distance. The distance may be indicated, for example, by the distance between the collar and the patient's skin or other anatomical tissue.

The elongate member 203 may be fixedly interconnected to the tips 201, 211 and the hub 204 in any suitable manner. For example, the tips 201, 211 may be press-fit into the elongate member 203, and the elongate member 203 may be press-fit into the hub 204. Other example methods of attachment include adhesive bonding and welding. In some embodiments, the elongated member 203 and the tips 201, 211 are a unitary structure. The elongate member 203 can be steerable and include a control mechanism to allow the elongate member 203 to deflect or steer after insertion into the anatomical structure.

Tubular body 207, including cavity 222, may comprise (e.g., be made of) any suitable material. For example, tubular body 207 comprises a conductive material, such as stainless steel (e.g., 300 series stainless steel), such that when RF probe 401 is inserted into tubular body 207, RF energy emitted by RF probe 401 can be conducted through tubular body 207 and into and through tips 201, 211, filars 206a, and/or filars 206 b. The tubular body 207 may be interconnected to the tips 201, 211 such that the cavity 222 is sealed, in fluid communication with the passage through the tips 201, 211. This may be achieved by press fitting, welding or any other suitable method.

As described above, the cavity 222 may be in fluid communication with the tips 201, 211 at the distal end 202. The proximal end of the cavity 222 may be disposed at the proximal end 205 of the lance 103. In this regard, the cavity 222 may extend from the distal end 202 to the proximal end 205, only in contact at the distal and proximal ends 202, 205. In some embodiments, the cavity 222 is only a cavity of the lances 103 arranged along the elongate member 203.

The RF probe 401 inserted into the cavity 222 may be positioned so that one end of the RF probe 401 is closest to the tips 201, 211. For example, the RF probe 401 may be positioned so that the distal end 402 of the RF probe 401 is in the cavity 222 near the tips 201, 211 or in a passage through the tips 201, 211. RF energy delivered through the RF probe 401 may then be conducted by the tip 201, 211, the filament 206a, and/or the filament 206 b. The dimensions of the cavity 222 may be selected to accommodate a particular size of RF probe 401. For example, the cavity 222 may be configured to accommodate at least 22gauge RF probe 401, at least 21gauge RF probe 401, or larger or smaller RF probe 401. As another example, the cavity 222 may have a maximum cross-sectional dimension of less than about 0.85 mm.

The proximal end of tubular body 207 is operable to receive RF probe 401. The proximal end of tubular body 207 and actuator 216 may be configured to receive a connector, such as a luer fitting, so that a fluid source may be connected to tubular body 207 (e.g., to flow fluid through lumen 222 and out fluid port 210).

The needle 103 includes two filaments 206a, 206b in and extending along the elongate member 203. The distal ends of the filaments 206a, 206b are adjacent the tips 201, 211, and the proximal ends of the filaments 206a, 206b are secured to a filament hub 221 described below. The filaments 206a, 206B are movable along a central longitudinal axis 223 between a fully deployed position, as shown in fig. 3A, 3C, 3D, and 3F, and a retracted position, as shown in fig. 3B and 3E. Moving the filaments 206a, 206b distally from the retracted position moves the filaments 206a, 206b toward the fully deployed position, while moving the filaments 206a, 206b proximally from the deployed position moves the filaments 206a, 206b toward the retracted position. The filaments 206a, 206b may be deployed in an intermediate position between the fully deployed position and the retracted position. For example, the mechanism for advancement and/or retraction of the filaments 206a, 206b may include a brake, which indicates partial deployment and/or retraction, and a stop, which indicates full deployment and/or retraction.

In the fully deployed position, the distal ends of the filaments 206a, 206b, 319a, 319b are disposed distal to the tips 201, 211, 311, 321. In the retracted position, the distal end of the filament 206a, 206b, 319a, 319b is entirely within the outer perimeter of the tip 201, 211, 311, 321 (e.g., the perimeter where the body portion 303 of the tip 201, 211, 311, 321 is circular). In the deployed position, the filars 206a, 206b, 319a, 319b can function as a broadcast antenna for the RF probe 401 (e.g., RF energy is delivered from the RF probe 401 to the tips 201, 211, 311, 321 and to the filars 206a, 206b, 319a, 319b and into a target volume within the patient). In this regard, the RF probe 401, the tips 201, 211, 311, 321, and the filars 206a, 206b, 319a, 319b inserted into the cavity 222 may together form a monopolar electrode for applying RF energy to the target volume. The filars 206a, 206b, 319a, 319b allow the RF from the RF probe 401 to be spread over a larger volume than could be present through the tips 201, 211, 311, 321 alone.

The filaments 206a, 206b, 319a, 319b can be constructed of a material operable to conduct RF energy, e.g., a metal, such as stainless steel (e.g., 303 stainless steel), nitinol, or a shape memory alloy. The filaments 206a, 206b may be coated, for example, to enhance and/or inhibit their ability to conduct RF energy. The filaments 206a, 206b may include a lubricious coating to aid in insertion and/or reduce tissue adhesion.

Fig. 2E illustrates an embodiment in which the filars 206a, 206b are formed from a single wire 206 bent at the proximal end. As shown, the distal ends of the filaments 206a, 206b are bent, which may be due to deflection away from the tips 201, 211, shape memory, combinations thereof, and the like. Forming the filars 206a, 206b from a single wire 206 may provide advantages such as coherent actuation of the filars 206a, 206b, simultaneous deployment of the filars 206a, 206b, and/or simultaneous retraction of the filars 206a, 206 b. It should be appreciated that the metal wire 206 may be a single wire or multiple wire segments bonded together (e.g., bonded by conductive epoxy, welded, soldered, combinations thereof, etc.). Other filaments disclosed herein may also be coupled or bent at the proximal end. The filaments 206a, 206b shown in fig. 2E are substantially parallel and taper outwardly prior to bending at the proximal end. In some embodiments, the filaments 206a, 206b are substantially parallel and do not taper outwardly prior to bending at the proximal end. In some such embodiments, the proximal end of the wire 206 is semi-circular, e.g., having a radius of about 0.03 inch to about 0.07 inch (approximately about 0.76mm to about 1.8 mm), about 0.04 inch to about 0.06 inch (approximately about 1mm to about 1.5 mm), about 0.05 inch to about 0.055 inch (approximately about 1.3mm to about 1.4 mm) (e.g., about 0.052 inch (approximately about 1.32 mm)), combinations thereof, and the like. In some embodiments, the filars 206a, 206b are parallel and spaced at a distance of about 0.025 inches to about 0.125 inches (approximately about 0.64mm to about 3.2 mm), about 0.05 inches to about 0.1 inches (approximately about 1.3mm to about 2.5 mm) (e.g., about 0.075 inches (about 1.9 mm)), combinations thereof, and the like. In some embodiments, the filaments 206a, 206b in the elongate member 203 may be braided, wound, or twisted together. Such an embodiment may increase the bulk strength, providing resistance to jamming and/or bending in the elongated member 203. In some embodiments, the wire 206 has a diameter of about 0.0025 inches to about 0.04 inches (approximately about 0.06mm to about 1 mm), about 0.005 inches to about 0.025 inches (approximately about 0.13mm to about 0.64 mm), about 0.01 inches to about 0.02 inches (approximately about 0.25mm to about 0.5 mm) (e.g., about 0.014 inches (approximately about 0.36 mm)), combinations thereof, and the like. Other diameters are also possible. In some embodiments, each filament 206a, 206b has a diameter of about 0.0025 inch to about 0.04 inch (approximately about 0.06mm to about 1 mm), about 0.005 inch to about 0.025 inch (approximately about 0.13mm to about 0.64 mm), about 0.01 inch to about 0.02 inch (approximately about 0.25mm to about 0.5 mm) (e.g., about 0.014 inch (approximately about 0.36 mm)), combinations thereof, and the like. Other diameters are also possible. In some embodiments, the filars 206a, 206b have different diameters (e.g., formed from different metal lines, formed from metal line portions having different diameters, coupled to form the metal line 206, etc.).

The distal ends of the filaments may be shaped (e.g., pointed) to improve their ability to pass through tissue. For example, the tips of the filaments 206a, 206b in fig. 3A have an outward facing slope. In some embodiments, the inclination has an angle of about 15 ° to about 45 °, about 20 ° to about 40 °, about 25 ° to about 35 ° (e.g., about 30 °), combinations thereof, and the like. In embodiments where each filament 206a, 206b has a diameter of about 0.014 inch (approximately about 0.36 mm) and a pitch of about 30 °, the pitch has a length of about 0.024 inch (approximately about 0.61 mm). The tips of the filaments 206a, 206b may have the same shape (e.g., have a slope) or different shapes. As another example, the tips of the filaments 206a, 206b in fig. 3D have an inward facing slope. In some embodiments, once deployed, the tilt (e.g., inward facing tilt) can help create a flare between the tips of the filaments 206a, 206b by tracking to one side (e.g., away from the tilted side), which can improve the placement of the filaments 206a, 206 b. As yet another example, the tips of the filaments 319a, 319b in fig. 3G have a pen point. In some embodiments, the pen point tip can reduce splaying between the tips of the filaments 206a, 206b by a substantially straight tracking arrangement, which can improve the arrangement of the filaments 206a, 206 b. In some embodiments, the filaments 206a, 206b comprise materials having different tensile strengths and/or rigidities, and the ability of the filaments 206a, 206b to bend, and thus the amount of splaying (if any), can be affected by contact with tissue. In certain embodiments in which the filaments 206a, 206b comprise a shape memory material, deflection to an unconstrained state may work in conjunction with or counter to the shape of the tip. In some embodiments, a particular filament tip may help occlude the filament slot, improve interaction with the transition region, and the like. Although particular combinations of filament tips are shown with respect to certain embodiments herein, various shapes of the filament tips described herein, etc. may be selected for any of these embodiments (e.g., the filaments 206a, 206b of fig. 3A may have inward-facing beveled or pointed tips, the filaments 206a, 206b of fig. 3D may have outward-facing beveled or pointed tips, the filaments 319a, 319b of fig. 3C may have inward-facing beveled or pointed tips, the filaments 319a, 319b of fig. 3G may have inward-facing beveled or pointed tips, etc.).

The positioning of the filars 206a, 206b of the embodiment shown in figures 3A and 3D will now be described in connection with figure 5. Figure 5 shows an end view of the tip 201 and deployed filaments 206a, 206b of the embodiment shown in figures 2A and 3A. The filaments 206a, 206b are positioned at a filament angle 503 about the central longitudinal axis 223 that is about 120 ° apart from each other. This corresponds with the position of the partial filament slots 304a, 304b described herein, as the filaments 206a, 206b emerge from the filament slots 304a, 304 b. Other filar angles 503 are possible. For example, the filament angle 503 may be about 90 ° to about 180 °, about 90 ° to about 150 °, about 100 ° to about 140 °, about 110 ° to about 130 °, combinations thereof, and the like. A filaless angle 504 of about 240 ° is defined as the maximum angle around the circumference of the filaless tip 201, 211. In embodiments consisting of two filars 206a, 206b, the filar angle 503 may be less than 180 °, and the filar-free angle 504 may be correspondingly greater than 180 ° (e.g., greater than 200 ° or greater than 240 °).

In fig. 5, the central longitudinal axis 223 is perpendicular to the plane shown. A midpoint 502 is defined between the distal ends 501a, 501b of the filars 206a, 206b, respectively. The midpoint 502 is offset from the central longitudinal axis 223. For example, in some embodiments, the midpoint 502 is offset from the central longitudinal axis 223 by about 2 mm. Other offset values are also possible. For example, the offset can be about 0.5mm to about 5mm, about 1mm to about 4mm, about 1mm to about 3mm, greater than about 0.5mm, less than about 5mm, combinations thereof, and the like. When RF energy is emitted from the tip 201 and the two filars 206a, 206b, the RF energy will be transmitted asymmetrically about the central longitudinal axis 223, resulting in RF energy being emitted from the tip 201 and the filars 206a, 206 b. As oriented in fig. 5, the energy is biased in an upward direction from point 301 toward midpoint 502. Thus, when RF energy is transmitted during an RF denervation procedure, a lesion will be created that is correspondingly offset from the central longitudinal axis 223 in a direction from the point 301 toward the midpoint 502.

Referring back to the asymmetry of the lesion, the lesion may be substantially a three-dimensional polygon of known size and volume (e.g., with rounded edges) that is offset from the central cannula in a known and predictable manner. Different embodiments may have different three-dimensional polygonal configurations that vary with the intended ablation target. By contrast, needles without deployable filaments may be used to create asymmetric planar lesions by varying needle insertion during the ablation procedure, and substantial ablation volume overlap may be required.

Figure 6 shows a side view of the tip 201 and filaments 206a, 206b oriented so that the deployed filament 206b is entirely within the plane of the figure. The filaments 206a, 206b extend from the tip 201 at a common distance or position along the central longitudinal axis 223. In some embodiments, the filaments 206a, 206b may extend different distances. The filament 206b is deflected radially outward from the central longitudinal axis 223. The filament 206b emerges from the tip 201 at an angle 601 of about 30 ° from the central longitudinal axis 223, which is parallel to the longitudinal axis of the elongate member 203. The angle 601 may vary, for example, based at least in part on the positioning of the transition region 305, the mechanical properties of the filament 206b (e.g., shape memory properties or lack thereof), and so forth. In some embodiments, the angle 601 may be about 5 ° to about 85 °, about 10 ° to about 60 °, about 20 ° to about 40 °, greater than about 5 °, less than about 85 °, combinations thereof, and the like. In some embodiments, angle 601 is associated with angle 503. For example, angle 601 may be a fraction of angle 503, such as about 1/4. In some embodiments, angle 601 is not associated with angle 503, e.g., both are independently selected to produce a particular lesion size or shape. In some embodiments, distal ends 501a, 501b are positioned distally beyond point 301 by a distance 602, are disposed at a distance 603 from central longitudinal axis 223, and/or are disposed at a distance 604 from each other. In some embodiments, distance 602 is about 3.5mm, distance 603 is about 3mm, and/or distance 604 is about 4.5 mm. Other distances are also possible. For example, in some embodiments, the distance 602 is about 0.5mm to about 6mm, about 1mm to about 5mm, about 3mm to about 4mm, combinations thereof, and the like. Other distances are also possible. As another example, in other embodiments, distance 603 is about 0.5mm to about 6mm, about 1mm to about 5mm, about 2mm to about 4mm, combinations thereof, and the like. Other distances are also possible. As yet another example, in other embodiments, the distance 604 is about 2mm to about 7mm, about 3mm to about 6mm, about 4mm to about 5mm, combinations thereof, and the like. Other distances are also possible.

The angles described herein (e.g., angles 503, 601) may be measured with respect to the needle 103 in a deployed state outside of the patient's body, and when the needle is inside of the patient's body, the angles may be based in part on the splaying of the filaments caused by the tilting, for example.

The tip 211 and the deployed filaments 206a, 206b of the embodiment shown in fig. 3D may also have a filament angle 503, a no-filament angle 504, a midpoint 502, an angle 601, distances 602, 603, 604, and other features described herein, such as those described with respect to fig. 5 and 6. In some embodiments, the portion of the lesion, and thus the shape of the lesion, based at least in part on the RF energy emitted by the tip 211 may vary based on the location of the point 301 (e.g., in fig. 3D, the point 301 is on the side of the tip 211 that includes the filaments 206a, 206 b).

The configuration of the filaments 206a, 206b shown in fig. 2A, 3D, 5 and 6 is operable to create a lesion radially offset from the central longitudinal axis 223 and distally offset from the point 301 as compared to a lesion created by the filament-free tips 201, 211 or as compared to a lesion created by the needle 103 with the filaments 206a, 206b in the retracted position.

Changes in the relative shape, location and size of the lesion created by the needle may be accomplished by repositioning the filament. For example, as described herein, the damage created by the needle will be in different locations depending on whether the filament is in the deployed or retracted position. Lesions having intermediate shapes, positions, and/or sizes may be achieved by positioning the filament at an intermediate position between a fully deployed (e.g., as shown in fig. 3A, 3C, 3D, and 3G) and a fully retracted position (e.g., as shown in fig. 3B and 3E). As described herein, a needle with an expanded filament may operate to create a greater lesion volume than a needle with a retracted filament. For example, a needle with fully deployed filaments may be operated to produce about 500mm³The volume of the lesion of (1). Other lesion volumes are also possible. For example, a needle with fully deployed filaments may be operated to create a lesion volume of about 100mm³To about 2,000mm³About 200mm³To about 1,000mm³About 250mm³To about 750mm³About 400mm³To about 600mm³Combinations thereof, and the like.

Further shape, location, and/or size changes of the lesion created by the needle with the deployable filament may be achieved by different configurations of the filament. Variations may include variations such as material, number of filaments, radial positioning of filaments, axial positioning of filaments, length of filaments, angle of filaments away from tip, shape of filaments, and so forth. By varying these parameters, the needle can be configured to produce lesions of various sizes and shapes at various locations relative to the tip. These variations can be specifically tailored for use in specific procedures, such as RF denervation procedures performed on specific nerves adjacent to specific vertebrae.

Material variations for the tip and/or filament may be selected to achieve a particular lesion size, location, and/or shape. For example, the tip may comprise (e.g., be made of) a material that does not conduct RF energy, in which case RF energy from the RF probe 401 may be conducted substantially only by the deployed filars. In certain such embodiments, the emission of RF energy from the filament may provide a greater offset from the central longitudinal axis 223 than would occur if the tip conducted RF energy and used as an electrode with the filament.

Another material related change that may affect the shape, size and/or location of the lesion is the addition and placement of insulators on the tip and/or on the filament. For example, by placing an insulating layer on the proximal portion of the filament extending from the tip when in the deployed position, the shape of the lesion can be altered because the RF energy is primarily emitted from the distal, uninsulated portion of the filament. As another example, the shape of the lesion may be altered by placing an insulating layer on the proximal portion of the tip, since the RF energy is primarily emitted from the distal, non-insulated portion of the filament. Other portions of the filament and/or tip, such as a distal portion of the filament and/or tip, a middle portion of the filament and/or tip, combinations thereof, and the like, may also be covered by an insulating material, such as the examples described with respect to fig. 3H and 3I.

In addition, the materials used in making the filament and tip can be selected based on RF conductivity. For example, by using a material for the tip that is less conductive to RF energy, the proportion of RF energy emitted from the tip can be varied compared to the energy emitted from the filament, resulting in a corresponding change in lesion size, location, and/or shape.

The RF needles and RF probes described herein may be constructed from Magnetic Resonance Imaging (MRI) compatible materials (e.g., titanium, aluminum, copper, platinum, non-magnetic 300 series stainless steel, etc.). In some of these embodiments, MRI equipment may be used to verify the positioning of the needle and/or portions thereof and/or to monitor the progress of the ablation procedure (e.g., RF denervation).

The number of filaments selected for the needles may vary in order to achieve a particular lesion size, location and/or shape. For example, as shown in fig. 7, a third filament 701 may extend from the tip 201' (or other tips described herein, such as the tip 211) at a location between the filaments 206a, 206 b. The tips 501a, 502b of the filaments 206a, 206b and the tip 702 of the filament 701 may form a polygon 703 having a centroid 704. The centroid 704 is offset from the central longitudinal axis 223. This arrangement may create lesions that are offset from the central longitudinal axis 223 to a different extent and have a different shape than the lesions created by the lances of FIG. 5. In general, when the centroid of the polygon formed by the tips of the filaments (or, where there are two filaments with a midpoint therebetween) is offset from the central longitudinal axis 223, the damage created by this configuration will be correspondingly offset from the central longitudinal axis 223. The filars 206a, 206b, 702 are at the same filar angle 503 of about 120 as in the embodiment of fig. 5. Other filar angles 503 are possible in fig. 5 or fig. 7. The embodiment shown in fig. 7 has an approximately 240 ° filarless angle 504, which is also the same as the embodiment in fig. 5. Other filar angles 504 are possible in fig. 5 or fig. 7. In general, in embodiments in which the filament is positioned at a filament angle 503 of less than about 180 °, the resulting lesion will be offset from the central longitudinal axis 223 in the direction of the filament. In embodiments where the filament is positioned at a filament angle 503 of less than about 180 °, the filaless angle is correspondingly greater than about 180 ° (e.g., greater than about 200 ° or greater than about 240 °).

As another example, as shown in fig. 8, four filaments 801a-801d are positioned around tip 201 "(or other tips described herein, such as tip 211). The tips of the filaments 801a-801d may form a polygon 802 having a centroid 803. The centroid 803 is offset from the central longitudinal axis 223. Such an arrangement may produce a lesion that is offset from the central longitudinal axis 223 in the direction of the centroid 803. The filaments 801a-801d are oriented at a filament angle 804 of about 200. Other filar angles 804 are possible. The embodiment shown in fig. 8 has a filarless angle 805 of about 160 °. Other filaless angles 805 are also possible. Fig. 8 illustrates an embodiment in which the filaless angle 805 is less than about 180 °, but which is capable of producing lesions that are offset from the central longitudinal axis 223.

In the embodiments described herein of fig. 2A, 3B, 5, and 6 having two filars, the midpoint 502 between the filars is discussed. In embodiments with more than two filaments, the centroid of the polygon formed by the distal ends of the filaments is discussed. Both the center point and the centroid can be considered to be the "average" point of its specially configured filament. In such embodiments, the midpoint between the filaments in the two filament embodiments and the centroid of the polygon in embodiments having more than two filaments may be offset from the central longitudinal axis of the elongate member. For example, the midpoint or centroid may be offset from the central longitudinal axis by 1mm or more. In an embodiment, the polygon may lie in a plane perpendicular to the central longitudinal axis.

For example, as shown in fig. 2A, 2D, 3A, 3C, 3D, 3G-3I, 5, 7,8, 9, and 10, the distal ends of the filaments may be in a common plane when fully deployed. In some embodiments, the common plane is perpendicular to or transverse to the central longitudinal axis. In some embodiments, the common plane is distal to the points 301, 312.

For example, as shown in fig. 2A, 2D, 3A, 3C, 3D, 3G-3I, 5, 7, and 10, the filaments of the needle may all be arranged on a common side of the central plane of the needle (where the central longitudinal axis lies entirely within the central plane). In some such embodiments, the distal ends of the filaments are all on a common side of the central plane. This configuration may result in the use of needles that are offset from the tip of the needle to the same side of the central plane of the end of the deployed filament.

For example, as shown in fig. 2A, 2D, 3A, 3C, 3D, 3G-3I, and 10, when fully deployed, the filament may point in at least a partial distal direction. In this regard, a vector extending longitudinally from the distal end of the filament and conforming to the central axis of the portion of the filament outside the tip 211 has at least some distal component. The fully deployed filaments in the embodiments shown in fig. 2A, 2D, 3A, 3C, 3D, 3G-3I, and 10 all point in at least a partial distal direction.

FIG. 9 shows an embodiment in which the filaments are evenly distributed around the circumference of the tip 201 "". The needle of FIG. 9 includes three filaments 901a, 901b, 901c distributed substantially equally around the circumference of the tip 201 "" with each angle 902a, 902b, 902c between the filaments 901a, 901b, 901c being about 120. Such needles may be operable to create lesions that are generally centered along the central longitudinal axis 223. However, the location of the lesion created longitudinally along the central longitudinal axis 223 may be determined by the configuration (e.g., length, angle of deployment, etc.) of the filament. For example, a relatively long filament may be operable to create a lesion positioned distal to a lesion created by a relatively short filament configuration. As another example, in embodiments where the filament 901b is longer than the filaments 901a, 901c, the needle may be operable to create a lesion that is offset from the tip of the needle toward the filament 901 b. As yet another example, in embodiments where the filaments 901a, 901b are longer than the filaments 901c, the needles may be operable to create lesions that are offset from the tips of the needles toward the filaments 901a, 901 b.

Referring again to fig. 7, if the filament 701 is distal to the filaments 206a, 206b, the resulting damage along the central longitudinal axis 223 is longer than that caused by embodiments in which the filaments 206a, 206b, 701 are each positioned along substantially the same plane perpendicular or transverse to the central longitudinal axis 223. In another variation, two or more filaments may be in the same radial position and in different axial positions after deployment. This embodiment may include multiple rows of filaments.

Referring again to fig. 5 and 6, if the length of the deployed portion of the filaments 206a, 206b is increased, the needles may be able to create lesions that are more distally located than the lesions created by the embodiment shown in fig. 5 and 6. The lengthening or shortening effects of the deployed length of the filament may be similar to those described herein with respect to partially deployed filaments.

In some embodiments, the needle comprises a filament having deployed portions comprising different lengths. In certain embodiments, where all of the filaments are deployed and/or retracted by a common actuator and/or as part of the same wire, filament length changes may be achieved by changing the overall length of the filament. For example, the distal end of the shorter filament may be retracted more into the tip or elongate member than the distal end of the longer filament. The lengthening or shortening effects of the deployed portion length of the filament may be similar to those effects discussed herein with respect to the variation of axially positioned filament exposure from the tip of the needle and/or with respect to partially deployed filaments.

The angle at which the filament exits the tip (e.g., angle 601 of fig. 6) can be varied to achieve a particular lesion size, portion, and/or shape. For example, if angle 601 in fig. 6 is about 60 °, the needle may be operable to create a lesion having a larger maximum cross-sectional dimension in a plane perpendicular to central longitudinal axis 223 than if angle 601 was about 30 °, for example because the filament is capable of emitting RF energy at a greater distance from the central longitudinal axis. In some embodiments, the filaments can be deployed at different angles 601 relative to the central longitudinal axis 223.

Referring again to fig. 10, the deployed portions of the filaments 1001a, 1001b may be bent. As described herein, the term "curved" may mean a continuous curve, a curve incorporating straight segments, multiple curves in different directions, combinations thereof, and the like. Such curvature may be achieved, for example, by filaments 1001a, 1001b comprising a shape memory material (e.g., nitinol) or a spring material. When the filaments 1001a, 1001b are retracted, the shape of the tip 201 and/or elongate member 203 may cause the filaments 1001a, 1001b to be in a constrained straight configuration. As the filaments 1001a, 1001b advance toward the fully deployed position, they become unconstrained and return to their curved shape as shown in fig. 10. The deployed shape of the filaments 1001a, 1001b may be predetermined, or the filaments 1001a, 1001b may comprise (e.g., be made of) a material that can be shaped by a user prior to insertion. The filaments of other embodiments described herein (e.g., fig. 3A, 3C, 3D, and 3G-3I) can also be curved. In some embodiments, one filament is curved and one filament is straight.

The curved filars 1001a, 1001b of figure 10 lie in a plane that includes the central longitudinal axis 223. In other embodiments, the filars 1001a, 1001b may be bent in other directions, such as in a corkscrew arrangement. This may be advantageous to help the filament remain anchored to the tissue during the delivery of RF energy. The curved filars 1001a, 1001b of figure 10 may operate to create lesions that are flatter in a plane perpendicular to the central longitudinal axis 223 than filars created as the straight filars 206a, 206b of figure 6.

In the embodiment shown in fig. 2A and 2B, the filaments 206a, 206B are shown extending the full length of the elongate member 203 from the filament hub 221 to the tip 201. In some embodiments, a single member may extend along at least a portion of the elongate member 203, and the filaments 206a, 206b may be interconnected to the single member at a point closest to the tip 201.

The illustrated embodiment shows all of the filaments of a given embodiment deployed or retracted together. In some embodiments, however, one or more filaments may be individually deployed and/or retracted. In some embodiments, multiple filaments may exit from the tip at a common location and form a fan-like arrangement as they expand.

The deployment of the filaments described herein has been described as movement relative to a fixed tip. In some embodiments, the filament may be deployed by pulling the tip backward relative to the filament (e.g., movement of the tip relative to a fixed filament). Movement of the tip rather than the filament may be advantageous, for example, in embodiments in which the needle is initially advanced until it contacts the bone to ensure proper positioning relative to the target tissue, and then the tip may be retracted, leaving the filament (e.g., the curved shape memory filament) in a precise, known position. In some embodiments, the filament may be deployed by advancing and retracting the filament to the tip.

Referring back to fig. 2A and 2B, the hub 204 may be fixedly attached to the elongate member 203. The hub 204 may be the main portion of the needle 103 that the user grasps during insertion and manipulation of the needle 103. The hub 204 may include an asymmetric member, such as an indicator 225 in an asymmetric known orientation relative to the tip 201. In this regard, the indicator 225 may be used to communicate to the user the orientation of the tip 201 within the patient. For example, in the embodiment shown in fig. 2A, the indicator 225 is fixed in an orientation circumferentially opposite the filament slots 304a, 304 b. Internally, hub 204 may include an internal cavity 213 sized to receive a longitudinal protrusion 218 of actuator 216. The hub 204 may include apertures and the protrusions 215 may protrude into the interior of the inner cavity 213 to control the movement of the actuator 216 relative to the hub 204 and to secure the actuator 216 to the hub 204. The hub 204 may comprise (e.g., be made of) any suitable material (e.g., thermoset plastic available from Bayer corporation2548）。

The actuator 216 may be used to control movement to deploy and/or retract the filaments 206a, 206 b. The actuator 216 is operable to move relative to the hub 204, the elongate member 203, and the tip 201 (e.g., parallel to the central longitudinal axis 223). The actuator 216 includes a longitudinal protrusion 218 that extends into the interior cavity 213 of the hub 204. The exterior surface of the longitudinal projection 218 includes a helical track 219 sized to receive the projection 215. In this regard, as the actuator rotates relative to the hub 204 (e.g., by a user to deploy the filaments 206a, 206 b), the helical guide 219 and the projection 215 combine to cause the actuator 216 to move longitudinally (e.g., parallel to the central longitudinal axis 223). The actuator 216 includes a contact surface portion 217 that can be grasped by a user when rotating the actuator 216. The interface portion 217 may be knurled or otherwise textured to enhance the user's ability to rotate the actuator 216. The hub 204 may also include a textured or shaped member (e.g., indicator 225) configured to enhance a user's ability to rotate the actuator 216 relative to the hub 204. The longitudinal protrusion 218 of the actuator 216 may include an internal cavity 226 sized to receive the filament hub 221 and allow the filament hub 221 to rotate freely relative to the actuator 216. In this regard, linear motion of the actuator 216 may be transferred to the filament hub 221 while rotational motion of the actuator 216 may not be transferred to the filament hub 221.

The actuator 216 may include a luer fitting 220 or any other suitable fitting type at its proximal end. The luer 220 may be in fluid communication with the cavity 222 and provide a connection so that fluid may be delivered to the cavity 222 and to the fluid port 210 of the tip 201, 211. Luer 220 may also be configured to allow insertion of RF probe 401 into cavity 222. The actuator 216 may comprise any suitable material (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, Inc.).

The filaments 206a, 206b may be fixedly interconnected to the filament hub 221. In this regard, longitudinal movement of the filament hub 221 by the actuator 216 may be communicated to the filaments 206a, 206b to deploy and retract the filaments 206a, 206b upon rotation of the actuator 216. The filament hub 221 may comprise any suitable material (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, Inc.).

The user can deploy or retract the filaments 206a, 206b by twisting or rotating the actuator 216. For example, as shown, counterclockwise (as viewed from the perspective of fig. 5) rotation of the actuator 216 relative to the hub 204 will cause the filaments 206a, 206b to deploy (extend), while clockwise rotation of the actuator 216 relative to the hub 204 will cause the filaments 206a, 206b to retract.

The filaments 206a, 206b may be partially deployed or retracted by partially rotating the actuator 216 relative to the hub 204. The actuator 216 and/or the hub 204 may include markings to indicate the position (e.g., depth or degree of deployment) of the filaments 206a, 206 b. The actuator 216 and/or the hub 204 may include detents to provide audible and/or tactile feedback of the position of the filaments 206a, 206 b.

In some embodiments, the filament may be deployed to a deployed position at the discretion of the user, either proximal or distal to a plane perpendicular to or transverse to the central longitudinal axis 223 at points 301, 312. For example, in some embodiments, full (e.g., 3/3) rotation of the actuator 216 may deploy filaments to a fully deployed position distal to a plane perpendicular to or transverse to the central longitudinal axis 223 at points 301, 312, partial (e.g., 2/3) rotation of the actuator 216 may deploy filaments to a partially deployed position in a plane perpendicular to or transverse to the central longitudinal axis 223 at points 301, 312, and partial (e.g., 1/3) rotation of the actuator 216 may deploy filaments to a partially deployed position proximal to a plane perpendicular to or transverse to the central longitudinal axis 223 at points 301, 312. The actuator 216 and/or the hub 204 may include components such as detents or detents to provide audible and/or tactile feedback regarding the degree of deployment (e.g., at 0/3, 1/3, 2/3, and 3/3) and/or the position of the filaments 206a, 206b (e.g., fully retracted, 1/3 deployed, 2/3 deployed, and fully deployed). Other scores are also possible, including scores of non-uniform spacing (e.g., a combination of 1/3, 1/2, and 4/5). In some embodiments, the selective controlled partial deployment allows for controlled adjustment of the lesion to any particular shape and/or conforming the filament to a particular anatomical structure (e.g., a bone structure).

Fig. 17A-17E illustrate the components of the mechanism at the proximal end 205 of the lance 103 of fig. 2D. This mechanism may also be used, for example, with the needle 103 of fig. 2A and other needles described herein. The assembly described with respect to fig. 17A-17E may include the components described herein with respect to fig. 2B and 2C, and an assembly described with respect to fig. 2B and 2C, for example, may include the components described herein with respect to fig. 17A-17E. Combinations of components are also possible.

Fig. 17A shows an exploded view of the components of the deployment mechanism of fig. 2D. The mechanism includes an advancing hub-like body or slide member 1710, a rotating ring or actuator 1720, and a main hub 1730. FIG. 17B shows a cross-sectional view of the advancing hub body 1710, the rotating ring 1720, and the main hub 1730 assembled together and half of the wire 206 shown in FIG. 2E. The advancing hub 1710 includes a stem or longitudinal projection 1712. The rotating ring 1720 includes a cavity 1721 extending from a proximal end to a distal end. The main hub 1730 includes a lumen 1731 extending proximally to a distal end. When assembled, stem 1712 of advancing hub 1710 is in cavity 1721 of rotating ring 1720 and in cavity 1731 of main hub 1730. The advancement hub 1710 can include annular protrusions 1714 that can interact with the annular protrusions of the rotation ring 1720 (e.g., annular protrusions 1714 having a larger diameter than annular protrusions 1724) to inhibit the stem 1712 from exiting the proximal end of the cavity 1712. In some embodiments, the annular protrusions 1714, 1724 include tapered surfaces that can interact to allow insertion of the stem 1712 and the annular protrusion 1714 into the cavity 1721 and include perpendicular surfaces to inhibit the annular protrusion 1714 and the stem 1712 from exiting the proximal end of the cavity 1721. Main hub 1730 includes a stem and longitudinal protrusions 1734. When assembled, stem 1734 of main hub 1730 is seated in cavity 1721 of rotating ring 1720. Other interactions between the advancing hub-body 1710, the rotating ring 1720, and the main hub 1730 are described herein, for example, with respect to fig. 17C-17E.

Fig. 17C shows a perspective view of the advancing hub 1710 and the example embodiment of the wire 206 of fig. 2E. The stem 1712 of the advancement hub 1710 includes a U-shaped recess 1713 configured to interact with the bent proximal end of the wire 206. Other shapes of the recess 1713 (e.g., V-shaped) are also possible. The recess 1713 may be complementary in shape to the proximal end of the wire 206. In some embodiments, the width of the recess 1713 is slightly less than the diameter of the wire 206 (e.g., about 0.001 inch (approximately about 0.025 mm)) so that after press fitting, the wire 206 is fixedly interconnected to the advancing hub 1710.

In some embodiments, the stem 1712 is shaped as shown in fig. 17C, which includes a vertical or transverse cross-section that includes a flat surface (e.g., the surface that includes the top of the recess 1713) and an arcuate surface, such as an oval with square ends. Cavity 1731 of main hub 1730 may include a complementary surface, such as a wider proximal portion, so that advancing hub 1710 is in a fixed rotatable position relative to main hub 1710 when stem 1712 is in cavity 1731. Other shapes and rotationally fixed configurations are also possible.

The proximal end of the advancing hub 1710 includes a fitting 220 (e.g., a luer fitting or any other suitable fitting). When assembled, the fitting 220 is adjacent the rotating ring 1720. The advancement hub 1710 includes a lumen 1711 extending from a proximal end to a distal end. A fluid delivery device, such as a syringe, can be attached to the fitting 220 to deliver fluid through the cavity 1711 and then through the cavity 1731 of the main hub, the cavity 308 of the elongate member 203, the cavity 306c of the tip 211, and out the fluid port 210 of the tip 211. The RF probe 401 may be inserted into the cavity 1711, then into the cavity 1731 of the main hub, then into the cavity 308 of the elongate member 203, and then into the cavity 306c of the tip 211. RF probe 401 may include a linker configured to interact with linker 220. The cavity 1711 may include a wide diameter portion in the region of the joint 220 and a narrow diameter portion in the region of the stem 1712, and a tapered surface 1715 that transitions from the wide diameter portion to the narrow diameter portion. The tapered surface 1715 may help guide the fluid and/or the RF probe 401 to the narrow diameter portion. In some embodiments, the narrow diameter portion of the cavity 1711 has a diameter of about 0.005 inch to about 0.05 inch (approximately about 0.13mm to about 1.3 mm), about 0.01 inch to about 0.03 inch (approximately about 0.25mm to about 0.76 mm), about 0.015 inch to about 0.025 inch (approximately about 0.38mm to about 0.64 mm) (e.g., about 0.02 inch (approximately about 0.5 mm)), combinations thereof, and the like. In some embodiments, the narrow diameter portion of the cavity 1711 has a diameter that is no greater than the diameter of any other cavity of the needle 103, such that fluid pressure will not occur at the distal end of the needle 103. For example, the narrow diameter portion of the cavity 1711 has a diameter of about 0.02 inches (approximately about 0.5 mm), the narrow diameter portion of the cavity 1731 has a diameter of about 0.05 inches (approximately about 1.3 mm), the cavity 308 of the elongated member 203 may have a diameter of about 0.05 inches (approximately about 1.3 mm), and the cavity 306c may have a width of about 0.02 inches (approximately about 0.5 mm). In some embodiments, the cavity 306c may be slightly smaller than the narrow diameter portion of the cavity 1711 and have the same effect, for example, due to small fluid losses through the cavities 306a, 306b and out of the filament ports 304a, 304b, which is acceptable because anesthetic and dye, for example, may permeate into the fluid and be adjacent to the filament ports 304a, 304b, even if only substantially dispersed from the fluid port 210. In some embodiments, the advancing hub 1710 comprises a polymer (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, inc.).

FIG. 17D illustrates a cross-sectional view of an example embodiment of a rotating ring 1720. This cross-section is along the same line in fig. 17B, but further components are visible, as they are not obscured by either the forward hub 1710 or the main hub 1730. As shown in fig. 17B, cavity 1721 is configured to at least partially contain stem 1712 and stem 1734, but not to contact fluid or RF probe 401. Cavity 1721 includes a helical guide 1722 sized to interact with a corresponding helical thread 1735 (fig. 17A) on stem 1734 of main hub 1730. As the spin ring 1720 is rotated relative to the main hub 1730 (e.g., by a user stabilizing the needle and grasping the main hub 1730 with a non-dominant hand and manipulating the spin ring 1720 with a dominant hand), such as to deploy the filaments 206a, 206b, the helical guides 1722 and helical threads 1735 interact, causing the spin ring 1720 and the advancement hub 1710 to move longitudinally parallel to the central longitudinal axis 223. In this regard, linear motion of the advancing hub 1710 relative to the main hub 1730 can be generated while rotational motion of the rotating ring 1720 may not be transmitted to the advancing hub 1710 and the main hub 1730. In some embodiments, about 1.25 to about 1.5 revolutions of the rotating ring 1720 fully unwinds the filaments 206a, 206 b. In some embodiments, about 0.75 to about 1.25 revolutions (e.g., one 360 ° rotation) of the rotating ring 1720 fully deploys the filaments 206a, 206 b. The configuration of the helical guide 1722 and helical thread 1735 can be adjusted to provide different levels of filament deployment with different levels of rotation of the rotating ring 1720. The outer surface of the spin ring 1720 may be textured or include features 1723 to assist a user in gripping the spin ring 1720 or twisting or rotating the spin ring 1720 relative to the main hub 1730. In some embodiments, the rotating ring includes helical threads 1735 and the main hub 1730 includes helical guides 1722. In some embodiments, the rotating ring 1720 comprises a polymer (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, Inc.).

Fig. 17E illustrates a cross-sectional view of the example embodiment of the main hub 1730 taken along line 17E-17E of fig. 17B, in an exploded view of the example embodiment of the elongate member 203. The proximal end of the elongate member 203 on the right side of fig. 17E includes a partial circumferential portion 1736. The distal cavity 1731 of the main hub 1730 includes a complementary partial circumferential portion 1737. Because the relative positions of the indicator 1733 and the partial circumferential portion 1737 are known, the partial circumferential portions 1736, 1737 can cause the elongate member 203 to be in a fixed and known rotatable orientation with respect to the main hub 1730, e.g., upon assembly. For example, the distal end of the elongate member 203 on the left side of fig. 17E includes the filament ports 304a, 304b on the same side of the partial circumferential portion 1736. Other partial circumferential portions and other complementary shapes are also possible. For example, the partial circumferential portion may include interlocking teeth. In some embodiments, the thickness of the partial circumferential portion 1737 is substantially the same as the thickness of the walls of the elongate member 1736 to provide a smooth transition between the cavity 1731 and the cavity 308. In some embodiments, the main hub 1730 includes a transparent polycarbonate (e.g., a thermoset available from Bayer corporation, such as2548). In some embodimentsIn (e.g., comprising 300 series stainless steel), the elongate framework comprises a hypotube in which components such as the filaments 304a, 304b and the partial circumferential portion 1736 are cut away (e.g., by laser, mechanical, chemical, or other cutting methods).

Other types of mechanisms may be used to control the deployment and retraction of the filaments. For example, in some embodiments, the mechanism includes a spring configured to bias the filaments 206a, 206b toward a predetermined position (e.g., fully deployed, fully retracted), similar to a spring-loaded mechanism used in retractable ballpoint pens. As another example, the mechanism may include a roller wheel, e.g., contained within the hub 204, that will advance or retract the filaments 206a, 206b when rotated, e.g., by a user's thumb. As yet another example, the hub 204 and the actuator 206 may interact through complementary threaded components. The filaments 206a, 206b will advance as the actuator 216 is threaded into the hub 204, and the filaments 206a, 206b will retract as the actuator 216 is threaded out of the hub 204. As yet another example, a Touhy-Borst type mechanism would be included to control the deployment and retraction of the filaments 206a, 206 b. Any other suitable mechanism for controlling the linear motion of the filaments 206a, 206b may be incorporated in the needle 103. Any of the mechanisms described herein can be used to control the deployment and retraction of the filaments of any of the embodiments described herein. For example, the mechanisms shown in FIGS. 2A-2D and 17A-17E may be used to deploy and retract the filaments shown in FIGS. 3A, 3C, 3D, 3G-3I, and 5-10.

Fig. 2C shows a partially cut-away and partially cross-sectional view of a portion of an alternative embodiment of a mechanism 230 that includes a hub 231 and an actuator 232 that may be part of the lance 103 used in an RF denervation procedure. The hub 231 may be fixedly attached to the elongate member 203. The hub 231 may be the main portion of the needle 103 that is gripped by the user during insertion and manipulation of the needle 103. The hub 231 may include an asymmetric component, such as an indicator 233, in a known orientation relative to the asymmetry of the tip 201. In this regard, the indicator 233 may be used to communicate the orientation of the tip 201 within the patient's body to the user. The hub 231 may include an internal cavity 234 therein that is sized to receive a longitudinal protrusion 235 of a slide member 236. The longitudinal protrusion 235 may include a key groove or key slot 237, which may extend in a longitudinal direction of the longitudinal protrusion 235. The interior surface of hub 231 through which longitudinal protrusion 235 moves may include a mating key (not shown) configured to fit and slide within key slot 237. The key slot 237 of the hub 231 and the mating key can together restrict the linear movement of the slide member 236 parallel to the central longitudinal axis 223.

The filaments 206a, 206b may be fixedly coupled to the longitudinal protrusion 235 of the sliding member 236 for longitudinal movement therewith. In this regard, distal movement of the longitudinal protrusion 235 relative to the hub 231 (e.g., to the right as shown in fig. 2C) may result in extension of the filaments 206a, 206b relative to the hub 231, the elongate member 203, and the tip 201. For example, distal movement of the longitudinal protrusion 235 may move the filaments 206a, 206b from the retracted position to the deployed position. As another example, proximal movement of the longitudinal protrusion 235 relative to the hub body 231 (e.g., to the left as shown in fig. 2C) may result in retraction of the filaments 206a, 206b relative to the hub body 231, the elongate member 203, and the tip 201.

The hub 231 may be made of any suitable material (e.g., a thermoset plastic available from Bayer, Inc., such as2548). The hub-like body 231 may be at least partially transparent so that a user may view the portion of the longitudinal protrusion 235 and/or other components of the hub-like body 231. The hub 231 may also include a boundary line (such as a cast or printed logo) so that the amount of extension of the filaments 206a, 206b may be determined by the position of the portion of the longitudinal protrusion 235 and/or other components relative to the boundary line.

The actuator 232 may be used to control the deployment and/or retraction movement of the filaments 206a, 206b fixedly connected to the longitudinal protrusion 235. The actuator 232 may be generally tubular so that it fits around a longitudinal hub projection 238 projecting from the proximal end of the hub 231. At least a portion of the lumen 234 can be within the longitudinal hub projection 238. The actuator 232 may also include an annular member 239 configured to fit in an annular slot 240 in the slide member 236. Annular member 239 can be sized relative to annular slot 240 such that actuator 232 can rotate relative to slide member 236 about central longitudinal axis 223 or an axis parallel thereto, while actuator 232 remains fixed relative to slide member 236 along central longitudinal axis 223. In this regard, the actuator 232 and the sliding member 236 may be configured to move in tandem (tandem) relationship along the central longitudinal axis 223. The ring component 239 and the ring slot 240 can be configured such that during assembly, the actuator 232 can press against the slide member 236 and the ring component 239 can snap into the ring slot 240.

The interior surface of actuator 232 may include a helical track 241 sized to receive a corresponding mating helical thread 242 on longitudinal hub projection 238. In this regard, as actuator 232 is rotated relative to slide member 236 and hub 231 (e.g., by a user to deploy filaments 206a, 206 b), helical guide 241 and helical thread 242 interact to cause actuator 232 and slide member 236 to move longitudinally along central longitudinal axis 223. In this regard, linear movement of the slide member 236 relative to the hub-like body 231 may be generated, while rotational movement of the actuator 232 may not be transmitted to the slide member 236 and the hub-like body 231. The exterior surface of the actuator 232 may be textured or may include features to aid in gripping the actuator 232 and twisting or rotating the actuator 232 relative to the hub 231. In some embodiments, longitudinal hub projection 238 includes a helical track 241 and the interior surface of actuator 232 includes helical threads 242.

The proximal end of slide member 236 may include a luer fitting 243 or any other suitable fitting type. The luer fitting 243 may be in fluid communication with a lumen through the sliding member 236 and may provide a connection so that fluid may be delivered through the luer fitting 243 and into the lumen of the sliding member 236. In turn, the lumen of the sliding member 236 can be in fluid communication with the lumen 234 of the hub 231, and the lumen 234 can in turn be in fluid communication with a lumen (e.g., lumen 222) in the elongate member 223. The cavity in the elongate member 223 may be in fluid communication with the tip 201 (e.g., fluid port 210). In this regard, fluid may flow into the luer 243, into and through the cavity in the sliding member 236, into and through the lumen 234 of the hub 231, into and through the elongate member 223, and out of the fluid port 210 of the tip 201. The luer fitting 243, the cavity in the sliding member 236, the inner lumen 234 of the hub 231, and the cavity of the elongated member 223 may also all be configured to allow insertion of the RF probe 401 therethrough. The protrusion 235 and the lumen 234 of the longitudinal hub-like projection 238 may be sized and/or configured to form a fluid-tight seal therebetween, allowing fluid to be delivered under pressure through the luer 220, through the lumen 238 and into the elongate member 203, substantially without leaking through the interface between the protrusion 235 and the lumen 234 of the longitudinal hub-like projection 238.

The filaments 206a, 206b may be fixedly interconnected to the sliding member 236, as described herein. Accordingly, axial movement of the sliding member 236 by the actuator 232 may be transferred to the filaments 206a, 206b to cause the filaments 206a, 206b to deploy and retract upon rotation of the actuator 232. The sliding member 236 may be made of any suitable material (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, Inc.). The actuator 232 may be made of any suitable material (e.g., Pro-fax6523 polypropylene homopolymer available from LyondellBasell industries, Inc.).

The user can deploy or retract the filaments 206a, 206b by twisting or rotating the actuator 232. The filaments 206a, 206b may be partially deployed or retracted by partially rotating the actuator 232 relative to the hub 231. The actuator 232 and/or the hub 231 may include detents to provide audible and/or tactile feedback of the position of the filament 206a, 206 b. As described herein, the detents can be configured such that audible and/or tactile feedback associated with engagement of the detents corresponds with a predetermined amount of deployment or retraction of the filaments 206a, 206 b. In this regard, the audible and/or tactile feedback may be used in determining the position of the filars.

In some embodiments, the lances 103 are multipolar (e.g., bipolar) devices as compared to the monopolar devices described herein. In some such embodiments, the filaments are isolated from each other and/or from the tip to enable bipolar operation (e.g., a filament having one pole and a tip having a second pole, one filament having one pole and one filament and tip having a second pole, one filament having one pole and one filament having a second pole, etc.). In embodiments where the needle 103 includes more than two filaments, elements may be included to allow selection of a particular filament polarity to aid in lesion shape, size, and/or location control. In some embodiments, the lances 103 may be used in a monopolar mode or a bipolar mode selected by the user. For example, RF probe 401 may include shapes, insulating members, etc., configured to produce a monopole or dipole.

The embodiments described herein of the lances may be used in spinal RF denervation procedures that will now be described. In general, for RF denervation procedures, the patient may lie down on a table top so that the user may contact the patient's spine. At any suitable time before, during, and/or after the procedure, the user may use an imaging device, such as a fluoroscope, to visualize the anatomy of the patient and/or to visualize the positioning of the device (e.g., the positioning of the needle relative to the target volume).

If desired, pain medication and/or intravenous solutions may be administered to the patient. Appropriate sterilization techniques may be used to prepare and maintain the patient's skin around the surgical site. In embodiments where the needle is monopolar, the return electrode pad 104 may be attached to the patient. Local anesthetic may be injected subcutaneously, either where the needle is to be inserted or along the approximate path of the needle, for example, by the needle itself or by a different needle.

With the filament in the retracted position, the needle can be introduced into the patient and moved to a target location relative to a target portion of the target nerve or to a target location relative to a target volume in which the target nerve can be located (all of which are generally referred to herein as the target nerve or a portion of the target nerve). The target nerve may be an afferent pain nerve, such as the medial branch nerve closest to the lumbar facet joint. Introducing the needle into the patient may include using the tip of the needle percutaneously to pierce the patient's skin. The movement of the needle may include navigating towards the target location using fluoroscopic guidance. Further, the movement of the needle may include advancing the needle to an intermediate position and then repositioning the needle to the target position. For example, the needle may be advanced until it contacts bone or other structure to reach an intermediate position. The needle may thereafter be retracted a predetermined distance to achieve the target position. The markings 224 or collars described herein may facilitate this procedure.

The needle may be used to inject anesthetic and/or dye adjacent the target nerve during needle movement or after the target site has been reached. The dye may improve contrast in fluoroscopic images to help visualize patient anatomy, which may help the user guide and/or identify the location of the needle.

The needle can be rotated about a central longitudinal axis of the elongate member of the needle to achieve a desired orientation relative to the target nerve. For example, the needle may be rotated so that the lesion created by the needle through the deployed filament will be offset from the central longitudinal axis toward the target nerve. This rotation of the needle may be performed before and/or after insertion of the needle into the patient. For example, the user may rotate the needle prior to insertion so that the needle is generally in the desired rotational orientation. Then, after reaching the target position, the user can fine-tune the rotational orientation of the needle to a more precise orientation by rotating the needle. As described herein, the hub or another portion of the needle outside of the patient's body may indicate the rotatable orientation of the needle.

Once the target location and desired rotational orientation have been achieved, the next step may be to advance one or more filaments of the needle relative to the tip of the needle. The particular lances used for the procedure may have been selected to enable specific sized and shaped lesions to be created at specific locations relative to the lances. The particular needle used may be of any suitable configuration as described herein (e.g., any suitable number of filaments, any suitable filament positioning, monopolar or bipolar, any suitable deployment and retraction mechanism, etc.).

In embodiments in which the needles are configured as shown in fig. 5 and 6 (e.g., about 120 ° apart), advancement of the filaments may include advancing the filaments such that a midpoint between the distal ends of the first and second filaments is offset from the central longitudinal axis of the needles and a terminal point of the filaments is distal of the tips of the needles when the filaments are in their respective deployed positions. This deployment may enable the needle to be used to create lesions that are offset from the tip of the needle toward the midpoint between the ends of the deployed filament. The resulting filament may also be positioned at least partially distally of the tip of the needle.

FIG. 11A shows a graph of an example set of isotherms 1010a-1010c that may be produced by the needle 103 of FIG. 2A. As shown by a set of isotherms 1010a-1010c, RF energy emitted from the tip 201 and from the filaments 206a, 206b may create an area of elevated temperature around the tip 201 and the filaments 206a, 206 b. The isotherms 1010a-1010c may be offset from the central longitudinal axis 223 such that the centroid of the isotherm shown in fig. 11A is offset from the central longitudinal axis 223 in the direction of the filars 206a, 206 b. The centroids of the isotherms 1010a-1010c shown in figure 11A may also be distal with respect to the tip 201 and between the tip 201 and the distal ends of the deployed filaments 206a, 206 b. The isotherms 1010a-1010c may also be shaped such that, as shown in fig. 11A, the isotherms 1010a-1010c have a maximum cross-sectional dimension along the central longitudinal axis 223 that is greater than a maximum cross-sectional dimension in the plane of fig. 11A perpendicular to the central longitudinal axis 223. As shown in the orientation shown in fig. 11B, the isotherms 1010a-1010c may have a maximum cross-sectional dimension along the central longitudinal axis 223 that is greater than a maximum cross-sectional dimension perpendicular to the plane of fig. 11A and perpendicular to the central longitudinal axis 223.

The offset of the centroids of isotherms 1010a-1010c from central longitudinal axis 223 may result in a greater lesion width in a plane perpendicular to central longitudinal axis 223 than a similarly sized straight needle without filars. The offset of the centroids of isotherms 1010a-1010c may also allow the centroid of the corresponding lesion volume to project in a direction away from central longitudinal axis 223. As an example, the offset may advantageously enable performance of the example procedures described herein. This offset may advantageously enable the creation of a lesion volume (e.g., a ossified procedure) at the distal end of the potentially obstructing structure (e.g., relative to the needle 103). The offset may also advantageously enable the needle 103 to be inserted into the patient at a more desirable angle (e.g., closer to perpendicular to the surface of the patient, such as within 30 ° of perpendicular to the surface of the patient), at a more desirable puncture location, and/or through a more desirable tissue than is attempted using a needle without the ability to offset the lesion.

FIG. 11B illustrates an example lesion 1011 map that may be created by the needle 103 of FIG. 2A. In fig. 11B, the lances 103 have been placed perpendicular to the surface 1012. Surface 1012 may be, for example, the surface of a bone, such as the lumbar spine. As shown, the filaments 206a, 206b are deployed such that they are adjacent to the surface 1012. In some embodiments, the contact surface 1012 may disadvantageously deform the filaments 206a, 206b, but may avoid such contact, for example, by the needle advancement and retraction procedures described herein. The lesion 1011 has a width along the surface 1012 that is wider than the lesion that would be created by the needle 103 if the filaments 206a, 206b were not deployed. This capability can be advantageous, for example, where it is known that a target structure (e.g., a nerve) will be located along surface 1012, but its exact location is unknown. In this case, the needle 103 may be positioned substantially perpendicular to the surface 1012 to achieve the lesion width along the surface 1012 as shown, where achieving the same lesion width along the surface 1012 using a needle 103 without deployed filaments 206a, 206b would require multiple repositioning steps or placement of the needle 103 substantially parallel to the surface 1012.

FIG. 11C illustrates an exemplary pattern of lesions 1022 that may be created by the monofilament needle 1020. The monofilament needle 1020 may be similar to the needle 103, but the monofilament needle 1020 includes only a single filament 1021. The filament 1021 may be constructed similarly to the filaments 206a, 206 b. The monofilament needle 1020 with deployed filaments 1021 may operate to produce a flat version of the filament 1022 that may be produced by a needle 103 with two deployed filaments 206a, 206b (e.g., thinner in a direction perpendicular to the central longitudinal axis 223, which is the left-right direction shown in fig. 11C). The ability to produce this lesion shape may be advantageous when it is desirable to have a relatively large lesion in a particular direction (e.g., to compensate for positional variability of the target nerve) and a relatively small lesion width in another direction (e.g., to avoid structures such as internal organs or the patient's skin). As described herein, certain embodiments of the needle 103 may allow for selective deployment and/or activation of the filaments 206a, 206b so that the needle 103 may mimic a monofilament needle 1020.

In embodiments where the needle is configured such that all filaments of the needle are deployed on a common side of a central plane of the needle (where the central longitudinal axis lies entirely within the central plane), filament advancement may comprise advancing the filaments such that the distal ends of all filaments are on the common side of the central plane when the filaments are in their respective deployed positions. This deployment enables the needle to be used to create lesions that are offset from the tip of the needle to the central plane on the same side as the end of the deployed filament. The lesion created may also be located at least partially at the distal end of the needle.

In embodiments in which the needles are configured as shown in fig. 7 or 8, advancement of the filaments may include advancing the filaments such that the distal ends of each filament define the vertices of a polygon having its centroid displaced from the central longitudinal axis of the needle when the filaments are in their respective deployed positions. The deployment may enable the needle to be used to create lesions that are offset from the tip of the needle towards the centroid. The lesion created may also be located at least partially distal to the needle tip.

Advancement of the filament may also be accomplished using any of the mechanisms described herein. For example, in the embodiment of fig. 2A, rotating the actuator 216 relative to the hub 204 may cause the filament to advance to the deployed position. Advancement of the filament may be performed such that each of the plurality of filaments passes through a surface of the needle parallel to the central longitudinal axis of the needle. In some embodiments, the filaments of the needle may be advanced to a position at an intermediate position between the retracted position and the fully deployed position. The degree of deployment may be based on the desired lesion size and/or accuracy of needle placement. For example, the same needle may be used in two different procedures where the target nerve is more variable in position in a first procedure than in a second procedure. In this case, a larger deployment of the filaments may be used in the first procedure, while in the second procedure, a lesser degree of deployment may be used, as a smaller lesion may be sufficient to ensure that the target nerve has been ablated. As another example, the position of the needle may be determined to be slightly offset from the target position after the needle has been deployed during the procedure. In this case, the filament may be deployed to a greater extent than would be required to accurately place the needle on the target. In this case, this greater degree of spreading can be used to compensate for inaccuracies in the positioning of the lances. In this case, repositioning of the lances and possible associated trauma may be avoided.

During and/or after advancing the filaments to the deployed position, their position may be verified using an imaging system (e.g., using a fluoroscope). Needles may also be used to stimulate the target nerve to verify proper filament positioning. For example, an electrical signal may be applied to the needle (e.g., up to about 2 volts applied at about 2 Hz), and the user may observe any relevant patient motion (e.g., fasciculation in the region of the neural supply). As another example, an electrical signal (e.g., up to about 1 volt applied at about 50 Hz) may be applied to the needle and an indication may be issued if the patient feels any associated sensation and its location to help verify proper needle positioning. This stimulation (user observation and/or patient reporting) can be used to stimulate the target nerve to determine if the deployed position is sufficient to effect denervation of the target nerve. In this regard, the stimulation is expected to affect the target nerve. Once it is determined that the target nerve is stimulated, higher energy may be applied to ablate the volume containing the target nerve.

The stimulation may also be used to attempt to stimulate nerves that are not targeted for nerve ablation/targeted nerves that are ablated (e.g., nerves that are not expected to be nerve severed) to determine the location of the needle relative to the non-targeted/non-targeted nerves. In this regard, if the stimulation signal does not stimulate the undetermined target nerve, the user may determine that the position of the needle relative to the undetermined target nerve is such that application of ablation energy to the needle will not result in significant damage to (e.g., ablation of) the undetermined target nerve. If the stimulation stimulates an undetermined target nerve (e.g., as determined by user observation and/or patient reporting), the needle may be repositioned to avoid damage to the undetermined target nerve. In this regard, it is desirable that the stimulation not affect the nerves of the undetermined target.

After proper needle positioning has been verified (e.g., by imaging and/or stimulation), anesthetic may be injected through the needle, e.g., out of fluid ports 210, 320, filament ports 304a, 304b, 318a, 318b, lumen 306c, etc.

After the filament has been advanced to the desired location, the next step may be to apply RF energy to the needle using an interconnected RF generator. In embodiments where a separate RF probe is used to transmit RF energy, the RF probe may be inserted into the lumen of the needle prior to application of the RF energy. When using this configuration, applying RF energy may include applying RF energy to the RF probe, and directing RF energy away from the probe through the tip and/or the filament.

The resulting RF energy emitted from the tip and/or filament may generate heat that ablates the target nerve. This ablation may be accomplished by creating a volume of the lesion that includes the target nerve. It is desirable to completely ablate the target nerve to prevent incomplete nerve severing that may lead to sensory disturbances and/or patient discomfort. For example, lesions of about 8mm to about 10mm in maximum cross-sectional dimension may be produced. Greater or lesser lesions may be created by varying the filament characteristics (e.g., filament advancement distance) and/or the RF energy level. The resulting lesion may be offset from the central longitudinal axis of the needle. The center of the lesion may be distal to the needle tip. It is well known that since RF energy is emitted from the tip and filament, lesions of a particular size can be produced by a lower peak temperature (the highest temperature experienced by the patient) than would be possible if a filament-free or un-deployed filament were used to produce needles of the same size lesion. For example, a particular lesion may be achieved by a needle with a deployed filament, where the peak temperature is about 55 ℃ to about 65 ℃, or less than about 70 ℃, whereas a peak temperature of about 80 ℃ would be required to produce the same lesion using a filament-free or non-deployed filament. This lower temperature achievable by having deployed filaments may lead to greater patient safety and/or procedural tolerances.

A temperature sensor (e.g., a thermocouple) at or near the tip of the needle can be used to monitor the temperature at or near the tip before, during, and/or after application of the RF energy. This reading can be used as a control signal (e.g., a feedback loop) to control the application of RF energy to the lances. For example, once temperature is detected, the needle 103 may be closed-loop controlled using control signals and/or temperature data by automatically adjusting parameters (e.g., frequency, wattage, and/or duration of application of RF energy and/or filament deployment length, needle position, etc.). A feedback loop involving the user is also possible. If it is desired to ablate additional target nerves or to ablate additional volume to ensure ablation of the original target nerves, the spinal RF denervation procedure can continue. In some embodiments, the distal end 402 of the RF probe 401 is a dual purpose wire capable of transmitting RF energy to the tip and/or filament and capable of functioning as a thermocouple (e.g., having heat sensing properties).

In embodiments where the needle is configured to create an injury off of the central longitudinal axis, and an additional target nerve or target volume is in a volume that can be ablated using the needle in its current position but in a different rotatable orientation, the procedure may continue as follows. First, the filament may be retracted into the needle after RF energy application is initiated. Once retracted, the needle may be rotated and the filament re-deployed. The re-deployment may have the same characteristics (e.g., length of the deployed portion of the filament) or different characteristics than the original deployment. The reoriented needle may then be used to at least partially ablate additional target nerves or target volumes. Retargeting of the ablation volume without repositioning (e.g., without withdrawing and reinserting the needle from the patient) may result in less patient trauma compared to known spinal RF denervation procedures, which may require removal and reinsertion of the needle to achieve the damaged second target volume. Furthermore, retargeting of the ablation volume without repositioning (e.g., by merely rotating the needle, without otherwise penetrating the tissue) may result in the ability to create unique molding lesions from a single insertion site. The shaped lesions may, for example, comprise lesions in the shape of two or more intersecting spheres or ellipsoids. The steps of retracting the filament, rotating the needle, re-deploying the filament, and applying RF energy may be repeated several times. In some embodiments, the second ablation volume may be defined by different deployment characteristics (e.g., length, RF energy parameters, etc.) of the filament without rotating the needle.

In embodiments where the additional target nerve or target volume is not within the volume that can be ablated by rotating the needle, the needle may be repositioned. Such repositioning may include partially or completely removing the lances from the patient's body, and then repositioning the lances and repeating the steps described herein. In some embodiments, the second ablation may be performed using a different needle (e.g., a needle having a different characteristic (e.g., a longer filament)) than the original needle.

When additional resection is not desired, the filaments of the needle may be retracted and the needle may be removed from the patient. After removal of the needles, a sterile bandage may be placed over one or more of the needle insertion sites. The patient's view may then be maintained and allowed to recover from the effects of any pain medication that may have been administered.

An example of a specific spinal RF denervation procedure will now be described. The unique steps of each procedure will generally be discussed, and the steps common to any spinal RF denervation procedure will not be discussed (e.g., site preparation, such as infiltration of the skin and subcutaneous tissue with 1.5% lidocaine to achieve skin anesthesia, incision of the skin to facilitate needle insertion, insertion monitoring by fluoroscopy, stimulation, etc., filament deployment mechanism, needle removal, etc.). Each of the procedures described is performed with a needle containing two filaments offset from a central longitudinal axis, such as described herein. It should be appreciated that variations of the needle configurations described herein may be used in these procedures. For example, to enhance the offset of the created lesion from the central longitudinal axis, curved filars (e.g., as shown in fig. 10) and/or partially insulating filars (e.g., as shown in fig. 3H and 3I) may be used to create different characteristics of the lesion (e.g., offset more from the central longitudinal axis).

1. Lumbar RF denervation of medial branch nerves adjacent to the lumbar zygapophyseal joint

The process may include the use of needles capable of creating lesions that are offset from the central longitudinal axis. The procedure will be described as being performed on the L5 vertebra 1101 of fig. 12 by the needle 103 of fig. 2A. It is understood that other embodiments and/or other lumbar vertebrae described herein may be used in the procedure or variations thereof.

The lumbar RF denervation procedure may include positioning the tip 201 of the needle 103 (e.g., using fluoroscopy navigation) so that the tip 201 contacts or is adjacent to the groove 1102 between the transverse process 1103 and the upper articular process 1104 of the targeted lumbar vertebra 1101. This positioning is shown in fig. 12. By contacting the lumbar vertebrae 1101, an active determination of the position of the lances 103 can be made. As an example, the positioning may be performed such that the needle 103 is within 30 ° of perpendicular to the lumbar vertebra 1101 at the point of contact with the lumbar vertebra 1101, or at the point of the lumbar vertebra 1101 closest to the tip 201 of the needle 103. Optionally, the needle 103 may be retracted from this position by a predetermined amount (e.g., about 3mm to about 5 mm), such as a predetermined amount as measured by the markings 224 on the needle 103, determined using a collar around the elongate member 203 described herein, and/or navigated by fluoroscopy.

The process may include rotating the needle 103 so that the midpoint 502 is oriented toward the superior articular process 1104 and the medial branch nerve 1105 located along the lateral side 1106 of the superior articular process 1104. The filaments 206a, 206b may then be advanced to the deployed position shown in fig. 12. The position of the needle 103 and the deployed filaments 206a, 206b may be verified using fluoroscopy and/or patient stimulation (e.g., motor and/or sensory). The RF probe 401 can then be inserted into the cavity 222 so that the RF energy emitted by the probe 103 is directed by the tip 201 and the filaments 206a, 206b to the target medial branch nerve 1105 and away from the medial branch of the posterior main nerve branch.

RF energy is then applied to the RF probe 401. The RF energy emitted from the needle 103 may preferably be deflected toward the target medial branch nerve 1105. The lesion created by this procedure may have a maximum cross-sectional dimension of between about 8mm and about 10mm, for example, and may resect a corresponding portion of the medial branch nerve 1105, thus resecting the nerve of the zygapophyseal joint.

In some embodiments, the lances may be operable to produce lesions that are substantially symmetrical with respect to their central longitudinal axis (e.g., as shown in fig. 9). In some such embodiments, the sequence of steps may include inserting a needle, deploying a filament, and applying RF energy.

In some embodiments, the lances may be inserted along the length of a portion of a nerve (as shown by lances 103' that are outlined in dashed lines). This positioning may be similar to known RF neurostimulation methods performed using filamentless needles. After positioning the needle, the filament may be deployed and a lesion may be created. As described herein, a needle having an expandable filament that is capable of producing the same damage as a needle without an expandable filament may have a smaller diameter than a needle without an expandable filament. While the positioning of the needle 103 'may be similar to known procedures, procedures utilizing a needle 103' with an expandable filament may be less traumatic and safer than procedures using needles without expandable filaments due to the smaller size of needles with expandable filaments. As described herein, the peak temperature that can produce the desired lesion volume can be lower when using a needle 103' with an expandable filament as compared to a needle without an expandable filament, which further contributes to patient safety. The filaments of the needle 103' may be partially or fully deployed to achieve a desired lesion location, shape, and/or size.

It will be appreciated that the illustrated deployment of the needle 103 with filaments 206a, 206b may be used to create a lesion that approximates the lesion that would be created by a filament-free needle placed in the location of the needle 103' (e.g., parallel to the target nerve 1105). Placement of the lances 103 substantially perpendicular to the surface of the L5 vertebra 1101 may be less difficult to achieve than parallel placement of the lances 103'.

2. Posterior nerve branch sacral joint (SIJ) RF denervation

The process may include the use of needles capable of creating lesions offset from the central longitudinal axis. The procedure will be described as being performed on the dorsal nerve branch 1201 of the SIJ of fig. 12 using the lance 103 of fig. 2A. It is understood that other embodiments of the lances and/or other portions of the SIJ described herein may be used in the described procedures or variations thereof.

As part of the SIJ RF denervation procedure, it may be desirable to create a series of lesions in a series of lesion target volumes 1203a-1203h transverse to the sacral foramen 1211, 1212, 1213 on one side of the sacrum 1200 to ablate the dorsal nerve branch 1201 responsible for propagating pain signals from SIJ. Since the precise location of the postganglionic branch 1201 may not be known, ablating the series of target volumes 1203a-1203h may include a change in the location of the postganglionic branch 1201. The series of target volumes 1203a-1203h may be in the form of one or more interconnected individual target volumes, such as target volumes 1203a, 1203 b. In some embodiments, the procedure further includes forming a lesion 1208 between the L5 vertebra 1209 and the sacrum 1200 to resect the L5 dorsal ramus.

The SIJ RF denervation procedure may include positioning the tip 201 of the needle 103 (e.g., using fluoroscopic navigation) so that it is in contact with or adjacent to a first point 1204 at the intersection of two target volumes 1203a, 1203b and in transverse relation to a SI Posterior Sacral Foramen (PSFA) 1211. This positioning may be performed such that the lances 103 are oriented within 30 ° of perpendicular to the sacrum 1200 at the point of contact (or at the point of the sacrum 1200 closest to the tip 201 of the lances 103). By contacting the sacrum 1200, an active determination of the location of the lances 103 can be made. Optionally, the needle 103 may be retracted a predetermined amount (e.g., about 3mm to about 5 mm), such as a predetermined amount as measured by the markings 224 on the needle 103, determined using a collar around the elongate member 203 described herein, and/or navigated by fluoroscopy. For example, a countertop oblique view may be obtained to determine that the tip 201 has not entered the spinal canal. For example, a fluoroscopic display view looking down the length of the needle 103 may be obtained to verify that the needle 103 is properly offset from the SI PSFA1211 and/or a fluoroscopic display view looking perpendicular to the central longitudinal axis 223 may be obtained to verify that the needle 103 is not below the surface of the sacrum (e.g., in the SI PSFA 1211). An electrical signal may be applied to the lances 103 to stimulate the nerves adjacent the tip 201 to verify proper lance 103 placement.

The SIJ RF denervation procedure may include rotating the needle 103 such that the midpoint 502 is oriented in the direction of arrow 1205a toward the first target volume 1203 a. The filaments 206a, 206b may then be advanced to the deployed position. The positions of the needle 103 and filaments 206a, 206b are verified using fluoroscopy and/or patient stimulation (e.g., motor and/or sensory). The RF probe 401 may be inserted into the cavity 222 before, during, and/or after the filament deployment in order to direct RF energy emitted from the needle 103 through the tip 201 and the filaments 206a, 206b to the first target volume 1203 a. RF energy may then be applied to RF probe 401. Preferably, the RF energy emitted from the lances 103 may be deflected towards the first target volume 1203 a. The lesion created by the applied RF energy may have a maximum cross-sectional dimension of between about 8mm and about 10mm, for example, and a corresponding portion of the postganglionic branch 1201 may be excised.

The filaments 206a, 206b may then be retracted and the needle 103 may be rotated approximately 180 ° so that the midpoint 502 is oriented in the direction of arrow 1205b toward the second target volume 1203 b. Optionally, some lateral repositioning of the lances may be performed (e.g., without any lance pullback, or with some amount of lance pullback and reinsertion). The filaments 206a, 206b may then be advanced to the deployed position. The position of the needle 103 and filaments 206a, 206b may be verified using fluoroscopy and/or patient stimulation (e.g., motor and/or sensory). During repositioning, RF probe 401 may remain in cavity 222, or may be removed and then reinserted. RF energy may then be applied to the RF probe 401 to create lesions corresponding to the second target volume 1203 b.

In this regard, two interconnected lesions may be created by a single insertion of the lances 103 (which may also be considered a single elliptical lesion). The number of probe repositioning steps can be greatly reduced, reducing patient trauma and the duration of the procedure, compared to methods in which the RF probe must be repositioned before each application of RF energy. In this regard, a continuous lesion area may be implemented around the SI PSFA1211 such that the lesion occupies a volume around the SI PSFA1211 from about 2:30 clock positions to about 5:30 clock positions (as shown in fig. 13). This injury may help achieve denervation of the dorsal nerve branch adjacent to SI PSFA 1211.

If desired, the procedure herein can be repeated to create lesions corresponding to the entire series of target volumes 1203a-1203h, thereby denervating the SIJ. For example, a first insertion may cut out volumes 1203a, 1203b, a second insertion may cut out volumes 1203c, 1203d, a third insertion may cut out volumes 1203e, 1203f, and a fourth insertion may cut out volumes 1203g, 1203 h. In this regard, a similar continuous damage region may be implemented around the S2PSFA1212, and a damage region from about 12:00 clock positions to about 3:00 clock positions (as shown in fig. 3) relative to the S3PSFA may be implemented around the S3PSFA 1213. The injury 1208 may also be created on the basis of the superior articular process of the L51209 posterior branch nerve in the groove between the superior articular process and the sacral body. The lances 103 may be inserted generally perpendicular to the plane of figure 13 to create the lesions 1208.

In some embodiments, three or more lesions may be created at a single location by the lances. For example, a needle positioned adjacent to a point 1206 of the three target volumes 1203c, 1203d, 1203e may be operated to create a lesion in each of the three target volumes 1203c, 1203d, 1203e, thus further reducing the number of needle relocations.

In some embodiments, each individual lesion corresponding to a series of target volumes 1203 may be created using a needle with an expandable filament, where the needle is repositioned before each application of RF energy. In certain such embodiments, the sequence of steps may be inserting the needle, deploying the filament, applying RF energy, retracting the filament, repositioning the needle, and repeating as necessary to create each desired lesion. For example, the procedure may be guided using needles that are capable of creating lesions that are symmetric to the central longitudinal axis of the needle (e.g., the needle in fig. 9).

3. Thoracic RF denervation of medial branch nerves

The process may include the use of needles that enable the creation of lesions that are offset from the central longitudinal axis of the needle. Successful treatment of thoracic z joint pain using radiofrequency ablation of the associated medial branch nerve may be challenging due to the inconsistency of medial branch position in the intertransverse space, particularly at levels T5-T8. The filaless needle is typically positioned at multiple locations in the intertransverse process space to achieve primary tissue ablation for successful medial branch denervation. Description this procedure will be performed using the needle 103 of fig. 14 and 2A on the intertransverse process space between adjacent vertebrae 1301, 1302 of the thoracic spine from T5-T8. It is understood that other embodiments of the lances described herein and/or other vertebrae may be used in the procedure or variations thereof.

The process may include obtaining a segmented leading-trailing image at the target level defined by counting from T1 to T12. It may then be that an image is obtained that is tilted about 8 ° to about 15 ° ipsilaterally to the non-sagittal plane of the vertebrae to transparently visualize the costal process joint clearly. This can improve visualization of the anterior transverse process, particularly in patients with reduced bone mass. This angle can help guide the probe to a thoracic vertebra anatomy safe region inside the lung, reducing the risk of pneumothorax.

The skin entry site of the lances 103 may be on the lowermost part of the transverse process slightly medial to the costal transverse process joint. Inserting the lances 103 may include navigating the device over transverse processes on the bone to contact the anterior transverse process slightly medial to the costal transverse process joint. The procedure may include pre-and post-examination imaging to demonstrate that the tip 201 of the needle 103 is in the superior lateral angle of the transverse process. The procedure may also include examining contralateral oblique images (e.g., ± 15 °), for example, to demonstrate that in the "Pinnochio" image, the target transverse process is in an elongated form. This figure may be useful for showing the relationship of the tip 201 of the needle 103 to the superior border of the transverse process of the target medial branch nerve. The process may include slightly retracting the tip 201 (e.g., about 1mm to about 3 mm). In some embodiments, retracting the tip 201 positions the port at the upper edge of the protrusion (e.g., visible through the radiopaque marker).

In some embodiments, medial to lateral placement may be performed by accessing the skin under the segmented spinous process and navigating the lances 103 over the transverse process to contact a point just adjacent to the superior azimuthal angle of the transverse process. The tip 201 may then be advanced to the exit 304a, 304b proximate the filaments 206a, 206b having the transverse upper edges, and the filaments 206a, 206b deployed.

The procedure may include rotating needle 103 so that midpoint 502 is oriented toward the intertransverse process space between vertebrae 1301, 1302 and medial branch nerve 1303 located therein. The filaments 206a, 206b may then be advanced anteriorly into the intertransverse process space between the vertebrae 1301, 1302 to a deployed position. The position of the needle 103 and the deployed filaments 206a, 206b may be verified using fluoroscopic visualization (e.g., using lateral imaging) and/or stimulation (e.g., motor and/or sensory), for example, to exclude the proximal abdominal branch. In some embodiments, the filaments 206a, 206b may be deployed in a ventral direction in the inter-transverse process space, which may be verified by obtaining a transverse image. An RF probe 401 may be inserted into the cavity 222 to direct RF energy emitted from the probe 103 through the tip 201 and the filaments 206a, 206b to the target medial branch nerve 1303. RF energy may then be applied to RF probe 401. Preferably, the RF energy emitted from the needle 103 may be deflected toward the volume between the vertebrae 1301, 1302. The lesion created by this procedure may have a maximum cross-sectional dimension of between about 8mm to about 10mm, for example, and may resect a corresponding portion of medial branch nerve 1303. This approach allows treatment of the medial branch as it curves out of the intertransverse space, entering the posterior space from the dorsal side. This directional deflection of the lesion may advantageously heat toward the target and away from the skin.

It should be noted that thoracic RF neurosurgery performed on other thoracic vertebrae may require different lesion sizes. For example, thoracic RF neurosurgery performed on the T3-T4 vertebra may require a smaller lesion volume than the procedures described herein, while thoracic RF neurosurgery performed on the T1-T2 vertebra may require an even smaller lesion volume. As described herein, the deployment of the filaments of the needle 103 may be varied to achieve this desired target lesion volume, or a different needle may be used (e.g., with shorter filaments in the fully deployed position).

4. Medial cervical branch RF nerve dissection

The needle embodiments described herein (e.g., needle 103 of fig. 2A) are capable of producing the tissue resection volume necessary to complete the neurosectomy of the cervical facet joint, including the C2/3 cervical facet joint (z-joint). Tissue resection of the cervical z-joint using the needle embodiments described herein can be accomplished using a single placement and a single heating cycle. This single deployment and single heating cycle may avoid unnecessary tissue damage from multiple deployments of filaless needles, as well as inadvertent damage to indirect tissue from excessive trauma. The resection area can be designed to provide sufficient and necessary tissue coagulation for a successful procedure, and thus may be expected to improve the outcome of patients undergoing spinal radio-frequency denervation.

Description this procedure of medial branch cervical RF denervation will be performed on the third occipital nerve at the C2/3z joint using the needle 103 shown in fig. 15. In fig. 15, the needle 103 is positioned between the C2 vertebra 1401 and the C3 vertebra 1402.

In a first step, the patient may be placed in a prone position on a radiolucent table suitable for performing fluoroscopic guided spinal procedures. The patient's head may be rotated away from the target side. Sterile skin preparation and coverage can be performed using standard well-known surgical techniques.

For the Third Occipital Nerve (TON) resection (C2/3 articular nerve distribution), the lateral ligament of the C2/3z joint is at an oblique or parasagittal, or alternatively ipsilateral rotation relative to the true sagittal plane of the cervical spine of less than or equal to about 30 ° (e.g., about 20 ° to about 30 °). Local anesthetics can penetrate the skin entry point. Then, when TON is the target, the tip 201 of the needle 103 is moved over the outermost bone of the joint post of the C2/3z joint, for example by using the "gun barrel" technique, to a first position contacting the bone closest to the rearmost and outside of the z-joint complex, to a point of maximum concavity for the level under C2/3, or a point of maximum concavity at the C2/3 level contacting the outermost and rear sides of the joint post.

Once bone contact is made, the needle 103 may be retracted a predetermined distance (e.g., about 1mm to about 3 mm) and the filament deployed toward the outside of the C2/3z joint. The filament will stretch to contain the expected longitudinal variation of the target nerve location (rossochaudal variation). The angle of the filament with respect to the tip can effectively encompass the ventral side of the joint column up to the border with the superior articular processes, thus including the advantage of a 30 ° oblique channel. Prior to filament deployment, the needle 103 may be rotated about the central longitudinal axis to ensure that deployment will occur in the desired direction.

Multiplanar fluorescence imaging may then be utilized to verify that the tip and filament are positioned as desired. For example, it can be verified that the filament is positioned so as to straddle the lateral articular hyaloid body and behind the C2/3 neural foramen. Useful imaging angles include Anteroposterior (AP), lateral and contralateral oblique (Sluijter) views. To further verify proper positioning of the needle 103, motor nerve stimulation may be performed by delivering a voltage of about 2Hz (e.g., up to 2 volts) to the tip 201 and filament, and sensory nerve stimulation may be performed at an appropriate voltage (e.g., about 0.4 volts to about 1 volt) and frequency (e.g., about 50 Hz).

After position verification, RF energy may be applied to the tip and the plurality of filaments to generate heat to ablate a portion of the third occipital nerve. The cross-sectional dimension of the lesion (e.g., about 8mm to about 10 mm) can include all medial branches and TON with a nerve diameter of about 1.5 mm. The directionality of the lesions, the offset towards the filament provides an advantageous safety measure for the skin and indirect structures with respect to undesired thermal damage. Safety concerns may be further met by fluoroscopic observation of the filaments at the back of the intervertebral foramen and/or lack of abdominal branch activation during stimulation (e.g., at 2Hz and 2 volts). After injury, the device may be removed. For the level below the C2/3z joint, the procedure may be similar to that described herein with respect to the third occipital nerve, except that the initial bone contact target is in the middle of the point of inflection of the joint column.

Other spinal RF procedures may also benefit from asymmetric RF energy application by the needle embodiments described herein. This asymmetry may be used, for example, to project RF energy in a desired direction and/or to limit RF energy projection in an undesired direction. The configuration of the filament may be selected to produce a desired size, shape and/or location of the lesion (relative to the needle tip) in the patient for a particular application. The location of the lesion may be offset distally and/or laterally outwardly from the tip of the needle as desired for a particular application.

It should be appreciated that the delivery of RF energy to tissue in the anatomy can be practiced for a variety of reasons, and that the embodiments of the lances described herein may be altered (e.g., modified or scaled) for use in other medical procedures. For example, the needle embodiments described herein can be used to deliver RF energy as a means to cauterize a "feeder vessel," such as in bleeding ulcers and/or in orthopedic applications. As another example, embodiments of the lances described herein can be varied for use in procedures such as cardiac ablation, where cardiac tissue is destroyed in an effort to restore normal electrical rhythm in the heart. Certain such uses can further benefit from the ability of the needle embodiments described herein to deliver fluids through a lumen, as, for example, a forming procedure in cardiac therapy may require the ability to deliver stem cells, Vascular Endothelial Growth Factor (VEGF), or other growth factors to cardiac tissue. The ability to manipulate embodiments of needles described herein may provide significant advantages in the field of cardiovascular drug delivery.

For example, the lances may be modified for use in heating the intervertebral disc. For example elsewhere for stimulating discography and/or therapeutic disc contact procedures, such asDiscectomy and cautery are described in which a predominantly longer needle (e.g., having a length of about 15cm, and a tip having an uninsulated active portion comprising a length of about 2mm, although other dimensions are possible) is placed in the posterior lateral edge of the painful disc. Once positioned in the posterior annulus, as confirmed by fluoroscopy, tactile feedback, and/or characteristic impedance readings, a single filament may be deployed in a sheet of looped fibers traversing the posterior annulus from lateral to medial, such as shown in fig. 18A and 18B, fig. 18A showing an axial view of a posterior oblique needle entering the posterior annulus through the tip of the principal axis, and deploying a filament moving from lateral to medial in the sheet of the posterior annulus, fig. 18B showing a sagittal view of the filament moving from lateral to medial across the posterior annulus.

In some embodiments, the filament may function as a thermocouple (e.g., comprising a material having the heat sensitive properties described herein) to allow for accurate measurement of the true temperature of the annulus. In some embodiments, the filament may include a lumen configured to allow injection of a therapeutic substance (e.g., methylene blue) upon retraction to substantially simultaneously chemo-thermal denervation, and/or to allow injection such as for verification of contrast agent placed within the annulus, which in turn may be the opposite of a potentially dangerous placement in the medullary cavity or a useless placement in the nucleus pulposus. In some embodiments, the filament has an exit angle of greater than about 30 °. In some embodiments, as the needle in the tissue advances away from the oblique angle, the filament includes a beveled kunck tip oriented to deflect from the intramedullary canal when advanced. In some embodiments, the deployed filament has a length of about 10mm to about 12 mm. In some embodiments, the needle does not include a cavity for injecting fluid. In some such embodiments, the area not occupied by the cavity may be used for the filament, which may be more complicated due to the use of thermocouples and/or the inclusion of cavities.

Bipolar or monopolar RF energy can be applied to the tip and to the filament, creating a therapeutically heated area through the posterior disc annulus and causing painful fibroid destruction in approximately the outer third of the annulus. This procedure can be repeated on the opposite side. In some embodiments, the needle may comprise a plurality of deployable filaments, and the spacing between the filaments (e.g., distance 604 in fig. 6) is about 2mm to about 10mm, about 4mm to about 8mm, about 5mm to about 7mm (e.g., about 6 mm), combinations thereof, and the like.

Example 1

The original muscle tissue portion was allowed to remain at 37 ℃ in a distilled water bath. The needle with the deployment tip was positioned to contact the tissue surface in 10 trials and to insert the tissue in 10 trials. The radio electron RFG3C RF generator power source was set at 75 ℃ for 80 seconds. The propagation of tissue coagulation is recorded by a video and calibrated forward looking infrared T400 thermography camera. The tissue sample is segmented and the coagulation zone is measured. Infrared observation demonstrated symmetric and homogeneous lesion propagation without hot spots or focal over-blocking. The volume average is calculated to be 467 +/-71 mm³Damage. Shaped as an elongated sphere that is skewed from a central axis toward the filament. Thus, the needles reliably create lesions that are potentially useful in spinal applications.

Example 2

A 47 year old male presented for radio frequency medial branch denervation with refractory right lumbar facet joint pain. A diagnosis has been made demonstrating greater than 80% remission by intra-articular z-joint injection and determination of medial branch block.

The patient is laid down on the fluoroscopy table in a prone position and a standard monitor is applied. No sedative agent was administered. Extensive preparation of the lumbar area with chlorhexidine alcohol and covering with a conventional sterile surgical procedure. The C-arm is adjusted to visualize/visualize the true AP of the L4/5 disc space while the vertebral endplates are in place and visualize the spinous processes located between the pedicle shadows. The C-arm is rotated 30-40 ipsilaterally to the target joint until the basis for SAP at L4 and L5 is clearly visible. The target point was determined as the midpoint of the basis of the SAP and the overlying skin and subcutaneous tissue was infiltrated with 1.5% lidocaine. A small skin incision is made through the 18-gauge needle to facilitate placement of embodiments of the needle described herein. Once the skin anesthesia has been established, the needle with the filament in the retracted position is advanced by the gun barrel method until bone contact is made with the foundation of SAP. The needle is then retracted slightly from the bone and the actuator is rotated 360 ° to fully deploy the filament using the serrations on the hub for orientation. The filament heuristically contacts the SAP-based bone. AP, oblique and transverse images were obtained to demonstrate the arrangement and to verify the guidance of the filament towards the SAP. In this position, the lesion is deflected to cover any variant medial branch nerve slightly above the SAP. If the filaments are not guided in the desired manner, they are retracted, the device is rotated as necessary, and the filaments are deployed. Activation by the activity of the multifidus muscle gradually gives motor nerve stimulation at a frequency of up to 2 volts at 2Hz, but without any anterior root innervating muscle tissue movement. A sensory nerve stimulation of 0.6 watts at 50Hz produces consistent pain in the patient's pain profile. For in vivo thermometry, a 22-gauge, 10cm, 10mm active tip RFK connected to a separately grounded second RF generator was placed in sequence at the following targets: (1) assessing the inferior and dorsal position in the neural foramen on the segment of the potentially heat-compromised spinal nerve; (2) lateral points on the transverse process adjacent to the medial/lateral branch locations of the posterior main branch; (3) during the stable heating period, the needle body is positioned on or near the central axis of the needle body; (4) on the basis and on SAP successively higher on the papillae to assess heating on the areas of potential MB changes (up to SAP). Then, the process was repeated in order to cut off the L5 nerve.

After the safe and optimal placement was verified by fluoroscopy and stimulation, the heating protocol was started in chicken egg white and chicken meat based on the above-described lateral nerve test. The experimental protocol includes: heating to 45 ℃ for 15-30 seconds, waiting for a rapid temperature rise that emits a primary stiffening signal of heating and physical change about the core axis; heating to 50 ℃ and keeping for 15 seconds; heating to 60 ℃ and keeping for 15 seconds; heat to 70 ℃ for 10 seconds to record only the well temperature.

The generator parameters during ablation are appropriate and within the tolerance of the genetic programming RF generator. The lower starting impedance relative to a monopolar needle may be explained by the larger conductive surface of the needle. Transient temperature fluctuations are noted as the damage propagates including the central axis of incorporation of the thermocouple. It should be understood that variations in the generator software may be useful for supporting the various embodiments of the apparatus. The impedance reading was 75 ohms to 250 ohms. The power range is 2 watts to 11 watts, and typically 3 watts to 4 watts after 10 seconds into the program.

The heat mapping results are as follows: (1) the perineural temperature (blot obtained through TC 2) at the superior proximal spinal nerve did not rise from the 38 ℃ baseline; (2) the temperature reading from TC2 is near the central axis of the temperature-transmitting needle of the reaction generator; (3) the temperature reading from the SAP base to the relative dorsal position on the SAP exceeded the 45 ℃ denervation threshold.

After this procedure, the patient experiences minimal discomfort. For the purposes of this complete disclosure, it is noted that the patient is the inventor of the present application. No postoperative pain relief is required. The patient reported substantially complete relief of his right lower back pain within 10 days of the procedure. After the RF procedure is demonstrated in table 1, bilateral cone EMG is performed at L3, L4, and L5:

TABLE 1 lateral taper EMG

Right L4 lateral cone and assessment of needles from the L5 lateral cone muscle showed higher insertion activity and slightly higher spontaneous activity.

All remaining muscles showed signs of no electrical instability.

At the levels of L4 and L5, there were diagnostic signs of electrical responses of active and intense denervation of the right lumbar spine. The left lateral cone on the contralateral side shows normal. These findings are consistent with the current clinical history of right lumbar radiculotomy.

Thus, the needle-shaped body is safely and effectively used to perform the lumbar medial branch nerve amputation. The heat map demonstrates compliance with the experimentally predicted safe and effective isotherms, and bilateral lumbar EMG demonstrates objective evidence of medial branch coagulation. The needle appears to be an effective extension of the prior art and technology. As a first example, the use of the "underbeam" technique to facilitate placement of a lumbar medial branch denervation is similar to diagnosing a medial branch denervation. The method can be applied to other spinal targets such as cervical spine z-joint denervation, thoracic spine z-joint denervation, sacral joint denervation, central innervation of the lateral CI-2 joint, RF denervation of thoracic spine sympathetic nerve trunk, RF denervation visceral nerve trunk at T10, 11, 12, RF denervation lumbar sympathetic nerve pain, and RF denervation upper and lower ventral plexus. As a second example, laboratory testing and in vivo thermal data demonstrate that large volumes are suitable for efficiently dealing with common changes in afferent sensory nerve pathways. The lesion can be directed toward the target and away from the sensory nerve indirect structure relative to the central longitudinal axis of the needle. As a third example, the needle can deliver meaningful motor and/or sensory nerve stimulation for proving a safe arrangement. As a fourth example, the lesion profile is driven by a needle design and does not require a longer time for high temperatures (e.g., over 80 ℃). It is believed that heating to 60 ℃ for 60 seconds is sufficient for most targets. Shorter procedure times and/or lower temperatures should translate to fewer complications, faster recovery, and/or less development of post-operative pain syndrome/dysesthesia. As a fourth example, the lances are of an uncomplicated and robust design that does not require additional support equipment and is economical to manufacture relative to other extensive damage techniques.

Although the present invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond certain disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while several variations of the embodiments of the present invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of ordinary skill in the art based upon this disclosure. It is also contemplated that various combinations and subcombinations of certain features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the embodiments of the disclosed invention. Thus, the scope of the invention disclosed herein should not be limited by the particular embodiments described herein.

Claims (12)

1. A needle, comprising:

an elongated member having a distal end;

a tip coupled to the distal end of the elongate member, the tip comprising a beveled portion comprising a point on one side of the elongate member; and

a plurality of filaments movable between a first position at least partially within the elongate member and a second position at least partially external to the elongate member to the side, the plurality of filaments and the tip configured to deliver radiofrequency energy from the probe to operate as a monopolar electrode,

wherein the elongate member has a proximal end, and wherein the needle further comprises a filament deployment mechanism coupled to the proximal end of the elongate member, the filament deployment mechanism comprising:

an advancing hub comprising a stem coupled to the plurality of filaments;

a rotating ring comprising a helical track, said stem of said advancing hub being at least partially inside said rotating ring; and

a main hub comprising a stem including a helical thread configured to cooperate with the helical track, the stem of the main hub being at least partially inside the rotating ring, the stem of the advancing hub being at least partially inside the main hub,

wherein upon rotation of the rotating ring, the filaments are configured to move between the first position and the second position,

wherein the plurality of filaments are formed from a single metal wire, and

wherein a proximal end of the wire is coupled to the stem of the advancing hub.

2. The needle of claim 1, wherein the inclined portion has an inclination angle between 20 ° and 30 °.

3. The needle of claim 1, wherein each of the plurality of filaments has a distal end that includes a slope away from the tip.

4. The needle of claim 3, wherein the plurality of filaments are inclined at an angle between 25 ° and 35 °.

5. The needle of claim 1, further comprising an insulating coating at least partially covering the dots.

6. The needle of claim 1, wherein the tip comprises a second stem at least partially within the elongate member, the stem comprising a first filamentous cavity and a second filamentous cavity.

7. The needle of claim 6, wherein the second stem comprises a third lumen, and wherein the inclined portion comprises a fluid port in communication with the third lumen.

8. The needle of claim 1, wherein the deployment mechanism comprises partially deployed indicia of the plurality of filaments relative to the tip.

9. The needle of claim 8, wherein the indicia comprises at least one of an audible and tactile detent.

10. The needle of claim 1, wherein at least one of the helical track and the helical thread comprises a plurality of detents configured to indicate partial deployment or retraction of the plurality of filaments.

11. The needle of claim 10, wherein the first position is a fully retracted position and the second position is a fully deployed position, and wherein the brake is configured to provide audible or tactile feedback to a user when the filament is in a third position between the first and second positions, a fourth position between the third and second positions, and a fifth position between the fourth and second positions.

12. The needle of claim 11, the plurality of filaments being adjacent to the point in the third position, the plurality of filaments being substantially longitudinally aligned with the point in the fourth position, and the plurality of filaments being distal to the point in the fifth position.