DE102006039471B3 - Body tissues treatment applicator for endovascular photodynamic therapy of thin hollow organ, has elastic unit formed such that distal section of fiber adopts permitted curved shape, and is pushed out of guide catheter - Google Patents

Abstract

The applicator (10) has an optical fiber with a cladding (2) comprising a defined recess with respect to a section of the cladding in a distal end section (13) of the fiber at several longitudinal coordinates. The recess has a vast portion of cladding thickness, and an elastic unit (6) is formed in such a manner that the distal section of the fiber adopts a permitted curved shape. The distal end section comprising a distal end of the applicator is pushed out of a guide catheter. An independent claim is also included for a method for manufacturing an applicator for treatment of body tissues.

Description

Technical application

The The invention relates to an optical fiber and a containing thereof Applicator, suitable for transfer of electromagnetic radiation in hollow organs of the body and for the Application of radiation for the treatment of body tissue, as well as a method for the production of the optical fiber. Preferred fields of application are those in which a sclerotherapy tissue, especially tumors, or sclerotherapy or suppression the conduction of the heart, especially the pulmonary veins reached shall be. About that In addition, the applicator for endovascular photodynamic therapy of thin Hollow organs suitable, such as. In interventional cardiology for the prophylaxis of restenosis.

State of the art

It has been known for some time, the application of body tissue with electromagnetic radiation, in particular laser radiation, for Generation of high temperatures for to use tissue coagulation as a surgical procedure. For laser therapy procedures such as photodynamic therapy (PDT) and laser-induced thermotherapy (LITT) is in many applications, the greatest possible depth of radiation he wishes. Deep in the body located places can be achieved when the radiation with the help of optical fibers via hollow organs or catheter introduced becomes.

by virtue of The strong scattering of radiation in the tissue decreases the power density a small radiation source with increasing penetration depth strong which reduces the depth at which tissues are effectively heated can, is limited. It is known in the art to use the tissue with the emerging from the distal end of an optical fiber To apply radiation. The diameter of the optical fiber and thus the radiating surface is typically 100-600 microns and is up through the for These applications require flexibility and flexibility of the fiber limited. This can be for a fixed position of the optical fiber only a comparatively small area be irradiated. The power density is very close to the fiber end high, falls However, even after distances of a few 100 microns from strong. Also regarding the effect of irradiation, which is closely linked to power density, thus arise big Gradients at short distances. This is problematic because for a successful one Treatment must be the heat generated in the tissue in a given temperature interval lie. For example, must for Effective laser-induced thermotherapy (LITT) of liver tumors in the tissue reaches a temperature of about 50-100 ° C and a certain Time to be kept. Such heating results due to denaturation the tissue proteins to the desired irreversible thermal cell damage and correspondingly heated tissue areas from. Too small temperatures lead to an incomplete destruction of the fabric, too high temperatures can lead to carbonation lead from tissue and also wound healing cause. This is particularly critical because the highest power density is present directly at the point of contact of fiber and tissue and in Case of carbonization of the tissue surface further spread the radiation in the tissue due to the high absorption of carbon even stronger limited or completely is prevented.

by virtue of the small size one area irradiated in this way is it for the treatment of a usually more extensive tissue area required to position the fiber at multiple locations. For this, e.g. attached to catheters bar marks to manually move the laser catheter forward or backward at defined intervals. If on a three-dimensional geometry line-shaped lesions by a juxtaposition represented by punctate lesions This is especially true of the beating heart Difficulty and requires special skill of the surgeon.

For some The problems described have already been different in the prior art Found solutions.

In particular, applicators are proposed, from which the radiation does not emerge, or not exclusively axially but also laterally. In this case, scattering bodies are often used, for example special plastics with embedded diffuser elements or light-scattering particles, which partially surround the end section of the optical fiber and are covered by a hose or a cap. The distal end of the fiber enclosed by the scattering body is completely freed of cladding over a certain length. Like in the DE 19739456 A1 and in the DE 10231463 A1 described, the possibility is already known, instead of using a separate additional scattering element by means of focused laser radiation to introduce scattering centers directly into the fiber core.

Alternatively, the US 20050135749 A1 To provide internal structures of translucent caps or covers of the distal fiber end with groove or notch-shaped structures. In the US 5871521 A Inside reflectors are described. However, these devices will additionally applied externally to the fiber and thus increase the diameter of the applicator significantly.

By Although the described laterally radiating applicators can indeed irradiated larger tissue areas become. However, all of these applicators produce one substantially cylindrical radiation field. Such is in many applications, however not suitable or at least not necessary. The possibility of adapting the generated radiation field for a particular application is not given in particular. Thereby is often a big one Lost part of the energy available in the optical fiber. It may even cause damage to healthy body tissue come. In particular, there is a risk of formation in blood vessels of coagulation, so for thermal therapy method with relatively high laser powers the Irradiation to the desired Place of action should be limited. So a vast area in the body tissue can be treated, if there is no adaptation of the generated radiation field the optical fiber or the applicator also here to several places be positioned.

For some applications, an extended, line-like exposure to electromagnetic radiation is required. This is the case, for example, in the suppression of the stimulation current conduction in the opening of the pulmonary veins. From the prior art, it is known to perform a high-frequency ablation with a so-called lasso catheter for this application. Likewise, eg in the US 2005267452 A1 Balloon catheter described in which radiation is radiated obliquely forward in an annular solid angle element. The radiation source sits in a balloon catheter, which can be positioned in a pulmonary vein, for example, thereby interrupting blood flow into the vein.

Of the Invention has for its object to provide an applicator whereby a radiation field can be generated, which is targeted to a extensive area to be treated in the body tissue, in particular in Hollow organs of the body, can be directed and is suitable, this is particularly homogeneous to warm up.

Presentation of the invention

The solution This technical problem is handled by an applicator for treatment of body tissue with electromagnetic radiation and a method of manufacture Such an applicator according to the independent claims. advantageous Embodiments and developments are specified by the dependent claims or can be understood from the following description and the embodiments remove.

According to the invention was recognized that the technical problem is due to an applicator for the treatment of body tissue can be solved with electromagnetic radiation, one in his desen Lichtleitfasser entire Length with a cladding fiber core, wherein the Sheath of the optical fiber in the distal end portion of several longitudinal coordinates each a defined, exactly a portion of the shell circumference relevant recess with a depth of at least a predominant Part of the shell thickness has, can escape through the radiation from the fiber.

The for the Treatment of body tissue provided Radiation thus becomes in the distal end portion of the optical fiber decoupled laterally. The decoupling takes place at several longitudinal coordinates the optical fiber in each case through a recess in the jacket of the optical fiber. The recesses are each limited to a specific one related true portion of the shell perimeter, i. a recess is located at each longitudinal coordinate only in a certain angular range. The decoupling of the radiation takes place at each longitudinal coordinate exclusively within a given (not necessarily common) Angle range. Preferably, only one lies at each longitudinal coordinate Recess in front; however, several recesses are possible as long as they only in exactly a portion of the shell circumference are located.

The applicator according to the invention thereby enables radiation to be coupled out laterally at a plurality of longitudinal coordinates, the simultaneous irradiation of a plurality of sites or one (essentially) one-dimensional, ie linear or two-dimensionally extended, area. In this case, the radiation can be targeted in certain solid angle, ie directed to certain zones in the body tissue, the radiation in other spatial directions, however, be avoided. It can thus be achieved that exclusively or almost exclusively tissue to be treated is exposed to radiation, while healthy tissue undergoes virtually no irradiation. Furthermore, the restriction of the recesses in each case over a certain angular range has the advantage that the length of the section of the optical fiber in which radiation is available with sufficient intensity and can be coupled out through the recesses is comparatively large. Furthermore, the optical fiber according to the invention or the applicator according to the invention has the advantage of being particularly stable, flexible and elastic. In particular, the optical fiber is particularly unbreakable, since the fiber core is surrounded in its full length by a jacket. Although this has at several longitudinal coordinates Ausspa on. However, since these are each limited to a certain angular range, ie because there is a recess in each longitudinal coordinate only in exactly a portion of the shell circumference, the stability and resistance to breakage is hardly limited. Therefore, the optical fiber or the applicator equipped therewith has a very wide range of applications. In particular, areas in the body which are very difficult to access, for example necessitating a highly curved access, can be safely reached and treated in the body with the applicator.

A Recess may be consistent according to the invention, i.e. The coat can be in the area of a recess in its entire Jacket thickness removed be. Possible But is also that a recess only a depth of a predominant Part of the jacket thickness has, i. that the jacket in the region of the recess a residual layer having a certain thickness, by which a certain proportion the radiation can escape. That still a part of the coat exists has the advantage that the stability of the optical fiber or the Applicator is particularly limited. In addition, can limits the power of the decoupled radiation and thus a otherwise, possibly excessive heating of the irradiated body tissue be avoided. Furthermore can be more guaranteed in this way be that over a sufficient length the optical fiber sufficient intensity of the radiation in the optical fiber for decoupling available stands. The jacket thickness is usually 5% of the core diameter, but can also be special Fibers are many times. For flexible fibers with core diameters from 50 to 400 μm is the strength of the jacket typically at 5 to 20 microns. In the area of a recess the jacket is preferably at least up to a residual layer of below 1 μm ablated.

Advantageous it is when at least 80%, preferably at least 90%, of the shell circumference the optical fiber at each longitudinal coordinate is not affected by a recess, i. that of a recess Affected portion of the shell circumference at most 20%, preferably at most 10%, of the shell circumference measures. This is at every longitudinal coordinate by far the largest (i.e. at least 80%) proportion of the shell circumference practically opaque. In order to on the one hand is the stability and Guaranteed breakage of the optical fiber, on the other hand allows that radiation only in a desired Solid angle is emitted and finally also ensured that the intensity the radiation in the optical fiber towards its distal end does not decrease too fast.

at the for The optical fiber used in the applicator is a highly flexible, thin fiber, preferably with a diameter of the fiber core of up to 600 microns, preferably at most 400 μm. fibers with higher Diameter are too large Bending radii on, i. are not sufficiently flexible. At the proximal End is electromagnetic radiation, preferably laser radiation of diode, solid-state or fiber lasers coupled. Usually Radiation in the infrared wavelength range is used because these a very big one has optical penetration depth.

The Recesses can for example, by a plurality of spaced openings or by a single elongated Slot be formed in the jacket.

A particularly flexible and stable embodiment of the invention is given, if the recesses in the fiber cladding are covered by several, at least 5, spaced openings given are. Such a configuration allows lateral decoupling the radiation over a vast area without the stability and flexibility crucial to impair. The cladding of the optical fiber is in fact only in the region of the openings, which each only make up a small part of the circumference of the shell, (completely or partially) removed. Between the openings In contrast, there are areas in which the mantle is fully present is. By a suitable special design and arrangement of the openings the applicator can be attached to a specific application, in particular Shape, size and accessibility the therapy site, be adjusted. The openings may be completely continuous, i. to the surface of the Fiber cores are sufficient, or partial, ie. that the coat in the area of the opening removed only to one on the fiber core adjacent residual layer is.

The openings can have a rectangular, round or oval cross-section. Of the Diameter or the width of the openings is typically between 5 and 100 microns. Preferably, at least two, in a particularly advantageous case all openings cross-sectional areas of different sizes. On this way can be considered be that the radiation intensity in the optical fiber in the direction of its distal end due to the lateral outcoupling of radiation decreases. By means of the variable cross-sectional area of the openings, taking into account this decrease in radiation intensity in the optical fiber in Direction of its distal end a suitable power density distribution the one from the openings emerging radiation can be generated. Is particularly advantageous it thereby, if each opening closer to the distal end one has larger cross-sectional area as a more distant opening. This makes it possible the decrease in the radiation density in the optical fiber in the direction of its compensate for the distal end.

Of the Distance between the openings is below 10 times, typically close to the two- to triple, the diameter or the width of the openings; preferably he 50 to 300 microns. Preferably, the distance is variable, i. two adjacent openings have a distance that is different from the distance between two others adjacent openings. Also, it can be taken into account the decrease of the radiation intensity in the optical fiber in Direction of its distal end, a suitable power density distribution of from the openings emerging radiation can be generated. Is particularly advantageous it does it when the distances between every two adjacent openings in the direction of the distal end of the optical fiber. Also so it is possible the decrease in the radiation density in the optical fiber in the direction to compensate for their distal end.

Of the Distance between the closest to the distal end of the optical fiber and the distal end of the optical fiber farthest opening and thus the length through the openings formed linear Arrangement is between 1 and 100 mm, preferably between 10 and 40 mm.

A wertere advantageous embodiment then given, if any opening has a predetermined Auskoppelgrad. The Auskoppelgrad an opening is thereby given by the ratio the radiant power exiting an opening to the immediate in front of this opening Radiation power present in the fiber. This embodiment has first the advantage that the extraction of radiation and thus the decrease of radiation intensity limited in the optical fiber is and thus guaranteed can be that a comparatively large radiation intensity over a huge Section of the optical fiber is available. In particular, can but also under consideration this decrease in radiation intensity in the optical fiber in Direction of its distal end a suitable power density distribution the one from the openings emerging radiation can be generated. For example, the Auskoppelgrad the opening be predetermined such that one, preferably each of the distal End closer opening one at least as big preferably larger Auskoppelgrad as a more distant opening. This also makes it possible the decrease in the radiation density in the optical fiber in the direction to compensate for their distal end. In a simple way can one certain degree of coupling of an opening be provided by the fact that the jacket in the region of the opening is not completely removed will, the opening thus not completely consistent is, but a certain residual layer of the sheath is maintained. Their thickness is just chosen that for the opening desired Decoupling is achieved. Alternatively or additionally, a specific Decoupling degree of an opening also be provided by the fact that the surface of the openings with a dielectric or thin Metallic coating is provided, which is a given Transmittance possesses. In this way, even for continuous openings a desired one Decoupling be set. In case of a continuous opening is located the coating directly on the surface of the fiber core and determines alone the Auskoppelgrad the opening. In the case of a residual layer having an opening closes the coating to the residual layer and determined together with the residual layer the Auskoppelgrad the opening.

In a further embodiment becomes the Auskoppelgrad of at least two, most advantageous Trap of all openings each chosen so that the decrease in the radiation density in the optical fiber in the direction its distal end is compensated such that the out of the openings emerging radiation has almost the same power.

at In the application, the applicator is usually in direct contact with the body tissue brought. The radiating openings preferably form a line or lie in a line tight side by side. This line-shaped Arrangement and in particular the distance and / or the size of the openings and / or the Auskoppelgrad the openings preferably selected overall such that by the scattering in the tissue and by overlapping the emission cone a linear Radiation characteristic and a line-shaped Verödungszone generated in the tissue becomes. Along the linear Arrangement is based on a very low body tissue depth, at least but from a body tissue depth of 500 μm, preferably 100 μm, a nearly homogeneous power density distribution.

Thereby can be targeted over an extended area in the body tissue along the entire for the treatment of body tissue provided distal end portion of the optical fiber, i. along the entire line formed by the erring openings one set appropriate power density and thus there along a this line is almost homogeneous, for the particular application desired warming be generated. Depending on the application, the heating is typically around 50-100 ° C. By the applicator according to the invention Is it possible, this warming to be confined to such areas of the body tissue, for the one desolation to be achieved in the tissue.

Instead of several spaced openings may be present according to an alternative embodiment of the invention, a single elongated slot. Since the slit width is less than 20%, preferably less than 10% of the cladding circumference, this embodiment also permits lateral decoupling of the radiation over a wide area without significantly affecting the stability and flexibility of the optical fiber. This embodiment has advantages in that the decoupling takes place continuously in the axial direction. The slot length is between 1 and 100 mm, preferably between 10 and 30 mm.

Preferably the slot has one over the slot length varying slit width. In this way can be considered be that the radiation intensity in the optical fiber in Direction of its distal end due to the lateral radiation decoupling through the slot decreases. By means of the varying slot width can be under consideration this decrease in radiation intensity in the optical fiber suitable power density distribution of emerging from the slot Radiation generated. It is particularly advantageous if the width of the slot towards the distal end of the optical fiber steadily or gradually increases. This makes it possible to reduce the radiation density in the optical fiber towards its distal end.

Of the Slit may in particular be formed so that the slot width in the direction of the distal end of the optical fiber changes such that the Power of emerging from the slot radiation per length element longitudinal is almost homogeneous. In this way it is possible the body tissue along the complete Slit evenly and homogeneous on one for to heat the application temperature suitable.

Especially can use the slot a linear radiation characteristic and a linear one desolation zone be produced in the tissue, wherein along the slot a nearly homogeneous power density distribution is present.

As in the embodiment with a multitude of openings can also in the embodiment with a single slot with the specification of a specific local Auskoppelgrades the power density distribution of the exiting radiation are suitably influenced. As a local Auskoppelgrad in this context, the ratio of at a longitudinal coordinate the fiber per length element the slot emerging from the fiber radiation power to the at this longitudinal coordinate understood in the fiber existing radiation power. Does that have Decoupling at a certain point in the slot a value of e.g. 5% per mm, it means that at this point from one 1 mm long slot area 5% of this longitudinal coordinate in the fiber existing radiation would be decoupled. The specification of a specific local Auskoppelgrades may alternatively or in addition to the variation of Slot width done. For the provision of a certain local Auskoppelgrades can for example, the slot will not be continuous to the fiber core, instead, the jacket in the region of the slot still with a Residual layer present. The strenght This residual layer is preferably used to obtain a desired Power density distribution of the exiting radiation along the Slot varies. For example, the residual layer, and thus the local Auskoppelgrad of the slot in the direction of the distal End of the optical fiber steadily or at least gradually decrease. A corresponding effect leaves also by coating the surface of the slot with dielectric or thin reach metallic layers, as already described for the openings.

The embodiment, at least one continuous opening or a continuous slot is present, can also be developed to the effect that to the at least one opening or to the slot in the fiber cladding is a recess in the fiber core connects, i.e. the at least one opening or the slot extends into the fiber core. A recess increased in the fiber core the decoupling at this point. The decoupling is all the more higher, the deeper the recess is. This offers another possibility the Auskoppelgrad the at least one opening or the local Auskoppelgrad to select appropriately along the slot. In particular, the Auskoppelgrad from opening to opening or along the slot by varying the depth of the recess be varied in the fiber core. So can the depth of the recess in the Fiber core preferably chosen so be that from opening to opening or steadily or gradually increases along the slot. Also This can in particular the decrease of the radiation density in the Optical fiber are compensated in the direction of its distal end. The depth of a recess in the fiber core is at most 20% of the fiber core diameter, so that a sufficient stability of the optical fiber ensures is.

A further aspect of the invention is the provision of a method for producing an optical fiber for use in an applicator provided for the treatment of body tissue with electromagnetic radiation, wherein the cladding of the optical fiber, by which the fiber core is enclosed in its entire length, in The distal end portion at a plurality of longitudinal coordinates in each case within exactly a portion of the shell circumference in such a manner from the outside with laser radiation is acted upon by ablation in each case a defined recess with a depth of at least a major part of the jacket thickness is formed, can escape through the radiation from the optical fiber.

The laser application for the ablation preferably takes place with an ArF or F ₂ excimer laser or a ps- or fs laser. As previously described, a plurality of spaced apertures or a single elongated slot are formed. In this case, the intensity, duration and / or number of laser pulses of the laser application is adjusted so that exactly one desired removal depth is achieved. This can correspond exactly to the sheath thickness, so that the sheath is completely removed to the fiber core, or may be slightly lower, so that a residual layer of the sheath is maintained with a desired layer thickness. Alternatively, it may also exceed the shell thickness if a recess is provided in the fiber core.

Preferably indicates the surface the optical fiber in the area of the openings or the slot structures or means on which the radiation characteristic of the exiting Change radiation in a targeted manner. In other words is the surface the optical fiber in the region of the openings or the slot designed such that a desired radiation characteristic is produced. This also makes it possible, the power density distribution along the linear Arrangement of the openings or along the slot for to adapt the respective application appropriately. In particular, the Training the surface or can the structures or funds effect or contribute to that already from one possible small body tissue depth a nearly homogeneous power density along the linear arrangement the openings or along the slot is present.

noted be that surface the optical fiber in the region of the openings or the slot depending on the embodiment of the invention (i.e., depending on the patency of the openings or the slot) in this area either with the surface of the Fiber core or with the surface of the Remaining layer of Mantes matches.

For example can the surface the optical fiber in the region of the openings or the slot be such or have such structures or means, that the exiting rays at least in the direction perpendicular to Fiber axis are collimated to limit the solid angle.

A such training of the surface can consist in that it consists of individual facets, in the the simplest case of two facets as in a prism, or out more like a segmented lens (Fresnel lens). alternative can the surface a curved one Possess contour, wherein the radius of curvature is perpendicular to the fiber axis. The generation of the openings by ablation with laser radiation is preferably carried out so that the curvature the surface about the original one cylindrical surface corresponds to the fiber.

The surface The optical fiber may be in the area of the openings or the slot also be designed in this way or have such structures or means, that the radiation characteristic in the axial and lateral directions is equal to. So there are structures or means available on act the beam path of the exiting radiation such that the Radiation characteristic adapted in the axial and lateral direction becomes. For this purpose, the surface of the openings or the slot, for example, with a grating or with a grid-shaped Be provided structure.

advantages It also has, if the structure of the surface of the optical fiber in the range at least one of the openings or of the slit is formed such that by refraction and / or Scattering of the radiation whose exit angle, at least either in the axial or in the lateral direction, is increased. In this way On the one hand, a larger tissue surface can be irradiated are, i. the available standing radiation power to be distributed over a larger area. on the other hand can for the embodiment with a multitude of openings be achieved in the mantle, that the emission cone especially strongly overlap and the linear arrangement the openings thus already at a very short distance from the applicator a linear emission characteristic having. This will help that even at particularly low body tissue depths a nearly homogeneous power density along the line-shaped arrangement of the openings present and a linear Desolation zone in the Tissue can be generated.

Especially This can be achieved by placing the surface of the optical fiber in the range at least one of the openings or the slot has a grid, grooved or wavy structure.

The Production of the lattice, groove or wavy structure can by a suitable modulation of the laser radiation during the generation of the openings or the slot can be achieved.

The distal end surface can be provided with a mirror coating. This can be achieved or supported that the existing at the distal end of the fiber laser power is not lost, but the radiation is reflected there and can be coupled out during the second pass. There Overall, the decoupled power increases.

The Optical fiber is provided at its distal end with a plastic sheath, e.g. a polymer. This enclosure preferably has the same or a higher one Refractive index on than the fiber core to a high degree of coupling ensure that the reflection losses during the passage from the thinner to denser medium are lower than vice versa. Before embedding the optical fiber in the plastic cladding become the recesses in the coat of fiber with a for the electromagnetic radiation transparent material, preferably a polymer, filled up, which preferably has a higher Refractive index has as the fiber core.

Of the Applicator can be used in a guiding catheter introduced be such that it is arranged axially displaceable therein. Enclosed by the guide catheter or through the guide catheter through the applicator can in this way to the therapy site to be brought. The guide catheter points a catheter tube having at least one axial channel for the applicator on. additionally the catheter tube can have further channels arranged lengthways to it, i.e. the catheter may be a multi-lumen catheter. The others channels can for example, for supply and removal of rinsing fluid, for probes e.g. for measuring the temperature or for electrodes for recording Signals, in particular used for the derivation of nerve signals become.

At the Therapy location is the distal end of the applicator, namely in Essentially, the part of the applicator by putting the the recesses having, distal end portion of the optical fiber is located off the guiding catheter pushed out. The plastic wrap covers the distal end of the Optical fiber over the optically active region, i.e. the outcoupling region, so far, that they are still up in the guide catheter extends into when the distal end of the optical fiber over the complete decoupling pushed out of the guide catheter is. Special advantages shows the invention when the applicator with at least one is equipped elastic element. The optical fiber is in In this case, together with the elastic element along each other embedded in the cladding. The elastic element is preferably preformed and capable of that - after pushing out the applicator from the guide catheter - free Force the end of the applicator into a given shape. The element is so elastic that it, and thus the entire applicator, inside the guide catheter can be brought in stretched form to the surgical site. It preferably consists of a polymer thread extruded in bent form or tube, a metal, a shape memory alloy or a Shape memory polymer.

By suitable choice and preforming of the elastic element, the Applicator can be flexibly adapted to the respective application. Thus, the light guide according to the invention or with a suitably preformed elastic element provided applicator for different applications are used. In addition, the Arrangement of the openings or slot with that of the applicator after pushing out the guiding catheter assumed form in such a way that the radiating openings or the slot in direct contact with the body tissue to be irradiated, and preferably exclusively with this, lie. In this way, a substantially linear or flat extensive area to be treated without relative movement between Applicator and this area are irradiated. In particular, can The irradiation is thus particularly well suited to this very treatment Limited area become.

In In practice, the invention can be used for example in such a way that for any different application (such as pulmonary vein isolation) one for this application optimized elastic element or an applicator equipped with it Depending on the application may also be available in different Sizes. Is possible it too, for every patient first Properties of the area to be irradiated, in particular its shape and to determine size and subsequently these qualities in the selection, shaping or manufacture of a suitable elastic element to flow in and the applicator to provide with it.

A Variety of different shapes, the free end of the applicator after pushing out of the guide catheter due to the preforming of the elastic element can, depending on the application be beneficial.

For the suppression of the stimulation current conduction in the opening of the pulmonary veins, a circular, circular lesion is advantageous, which can be achieved by forming a circular loop as in a Lassokatether. This shape is suitable for placing on the funnel-shaped opening of the vein. Alternatively, a spiral or helical configuration (similar to an immersion heater) is conceivable, which is introduced into the opening of the vein and rests close to the inner surface of a vessel. As a result, a spiral-shaped line can be irradiated whose total azimuth comprises more than 360 °. In this way, it can be a complete isolation in the axial direction with axially extending stimulus lines be targeted because each stimulus pathway is interrupted at least once. A similar multi-turn design over a distance of at least 10 mm would be suitable for PDT of vessel internal walls for prophylaxis of revascularization following interventional intervention for vascular recanalization. In a special embodiment for very thin vessels, however, an applicator in stretched form would be used, whose lateral surface is provided with openings in a spiral shape in order to achieve a radial radiation to the vessel wall.

Brief description of the drawings

The The present invention will now be described with reference to exemplary embodiments in conjunction with the drawings without limiting the scope of the claims Protection area again closer explained. Hereby show:

1 FIG. 4: a longitudinal section of the distal end of an applicator. FIG

2a , b, c: in each case a cross-section of an applicator

3 FIG. 2 is a side view of the distal end portion of an applicator having a plurality of apertures. FIG

4 FIG. 2: a side view of the distal end portion of a slot applicator. FIG

5 : an example of the form adopted by the applicator after being pushed out of the guide catheter

6 : Another example of the form adopted by the applicator after being pushed out of the guide catheter

7 : Another example of the form adopted by the applicator after being pushed out of the guide catheter

8th An embodiment of the invention with a multi-lumen guiding catheter

9 A further embodiment of the invention with a multi-lumen guiding catheter

10 : A sketch of an applicator, whose spiral-shaped windings attach to an inner wall of a vessel in the body.

11 : A sketch of the use of an applicator for the suppression of the stimulation current conduction in the opening of the pulmonary vein

Ways to execute the invention

In 1 is a (not to scale) longitudinal section of the distal end 13 an applicator 10 shown in stretched form. One recognizes fiber core 1 and coat 2 as well as at the distal end 12 the optical fiber multiple, pointing in the same direction openings 4 in the coat of fiber. The optical fiber is embedded in a plastic sheath 3 , In addition to the optical fiber is an elastic element 6 , which is also embedded in the plastic cladding. The distal end surface 5 the optical fiber is mirrored. The optical fiber has a diameter of 200μm, made of optical fiber, elastic element 6 and plastic cladding 3 existing applicator 10 has a diameter of less than 3 mm.

In 2a is a (not to scale) cross-section of an applicator 10 shown. You can see the fiber core 1 , the coat 2 and the plastic wrap 3 , The jacket has a recess at the present longitudinal coordinate of the optical fiber 7 on. The coat 2 is not completely removed in this area, but there is still a residual layer 8th of the coat 2 in front. This residual layer 8th typically has a thickness of less than 1 μm.

In 2 B is a (not to scale) cross section of another embodiment of an applicator 10 shown. In this case, the coat is 2 in the area of the recess 7 unlike in 2a completely removed.

In 2c is a (not to scale) cross section of another embodiment of an applicator 10 shown. One recognizes again the fiber core 1 , the coat 2 and the plastic wrap 3 , The jacket has a recess at the present longitudinal coordinate of the optical fiber 7 on. As in 2 B is the coat 2 In this area completely removed, moreover, in this embodiment, a part of the fiber core is removed, ie where the fiber core is exposed through the recess in the fiber cladding, there is additionally a recess 17 in the fiber core 1 in front. The depth of erosion in the nucleus 1 is typically up to 20% of the core diameter.

In 3 is a (not to scale) side view of the distal end portion of an embodiment of the applicator according to the invention 10 shown. The coat 2 The optical fiber has a plurality of openings in this embodiment 4 through which radiation can escape. The openings 4 have a round cross section. Their diameter increases from opening to opening in the direction of the distal end 12 the optical fiber to and varies between a size of 20 microns for the first opening, ie those with the greatest distance to the dis at the end of the applicator, and a size of 100 μm for the last opening, that is, the one closest to the distal end of the applicator. The distance between the first and last opening is 10 mm.

In 4 is a (not to scale) side view of the distal end portion of another embodiment of the applicator according to the invention 10 shown. The coat 2 The optical fiber has a single elongated slot in this embodiment 9 on, can escape through the radiation. The slot 9 has a length of 10 mm. The slot width increases steadily in the direction of the distal end of the applicator and varies between a width of 20 μm at the slot beginning facing away from the distal end of the applicator and a width of 100 μm at the slot end facing the distal end of the applicator.

In 5 is the rough sketch of an applicator 10 shown after sliding out of the guide catheter 11 assumes a curved shape similar to the shape of a lasso. Such a form is particularly suitable for circular Verödungen funnel-shaped vascular openings in hollow organs such as the isolation of the conduction to a pulmonary vein. In use, the lasso-shaped bent applicator is applied to the inside of the funnel-shaped vessel opening, wherein the plane defined by the Lasso form is substantially perpendicular to the funnel axis. The radiating openings, not shown in this sketch, are arranged so that they can be brought into contact with the body tissue to be irradiated in this application.

At the in 6 shown rough sketch of the applicator 10 is the elastic element (not shown) 6 so preformed that the applicator 10 after pushing out of the guide catheter 11 forming a spiral, that is, spiraling in a plane such that through several turns of the applicator 10 a surface which is almost completely filled up to a small area in the center of the spiral is created. The openings (not shown) in the fiber cladding point substantially in the direction of the normal of this area to one side. This is formed by the applicator in the plane surface several millimeters extended, radiating perpendicular to the plane surface radiator. In this way, extended flat areas in the body tissue can be exposed to radiation, without the need for a complex multiple positioning of the radiation source is required. This arrangement would be further suitable for the annular sclerosing of areas with a few mm in diameter. The arrangement of the openings, in particular their distance, and / or the openings themselves, in particular their respective Auskoppelgrad and their respective Abstrahlcharakteristik, are designed so that due to the uniform distribution of the radiation intensity and the intersections of Abstrahlkegel and the scattering in the tissue is a nearly homogeneous Radiation distribution is present.

In 7 is shown schematically another form, which is the free end of the applicator 10 after pushing out of the guide catheter 11 can assume (it is only outlined the form, for further details was omitted for reasons of clarity). This shape is spiral (similar to an immersion heater) and is intended for use in (nearly) cylindrical vessels. After pushing out of the guide catheter, the applicator lays down 10 Close to the inner surface of the vessel, so that a spiral-shaped line is irradiated, which covers more than 360 ° in total. In this way, a complete isolation in the axial direction can be achieved with axially extending stimulus lines. Such a shaped applicator is also suitable for the PDT of vessel inner walls for the prophylaxis of a revascularization after a balloon dilatation and insertion of a stent.

In 8th and 9 embodiments of the invention are shown in which the applicator 10 in a multi-lumen catheter 11 to be led. Next to the lumen 14 for the applicator 10 There are two more lumens 14 which can be used for rinsing or electrodes for recording signals. The in 8th respectively. 9 shown applicator 10 corresponds to the already in 5 respectively. 6 described applicator 10 ,

10 shows the situation in the vessel 15 for an applicator 10 to 7 , After exiting a lumen 14 of the here 2-lumen guide catheter 11 arises due to the elastic element 6 a spiral shape, with the turns close to the vessel wall. The openings 4 or recesses 7 are arranged on the lateral surface so that they are in contact with the inner surface of the vessel and the radiation is emitted in the direction of the vessel wall.

11 shows schematically the situation in the left atrium of the heart 18 for an applicator 10 to 8th , The guiding catheter 11 is from the left ventricle 19 passed through the atrioventricular valve or mitral valve into the left atrium. There is the lasso-shaped applicator 10 on or the funnel-shaped opening 16 placed in a pulmonary vein.

1

fiber core

2

fiber cladding (Cladding)

3

Plastic covering

4

Opening in fiber cladding

5

mirrored end face the optical fiber

6

elastic element

7

recess in the fiber coat

8th

residual layer of the fiber jacket

9

slot in the fiber coat

10

applicator

11

guide catheter

12

distal End of the optical fiber

13

distal End portion of the optical fiber

14

lumen of the guide catheter

15

vessel

16

Opening one pulmonary vein

17

recess in the fiber core

18

heart

19

left ventricle

Claims (31)

Applicator ( 10 ) for the treatment of body tissue with electromagnetic radiation, with an optical fiber, which in its entire length with a cladding ( 2 ) provided fiber core ( 1 ), and with an elastic element ( 6 ), wherein the applicator ( 10 ) into a guide catheter ( 11 ) is insertable and can be arranged axially displaceable therein, characterized in that the cladding ( 2 ) of the optical fiber in its distal end portion ( 13 ) at a plurality of longitudinal coordinates in each case a defined, exactly a portion of the cladding circumference relevant recess ( 7 ) having a depth of at least a major part of the cladding strength, can escape through the radiation from the optical fiber, and wherein the elastic element ( 6 ) is formed and preformed such that the distal end portion ( 13 ) the optical fiber assumes a predetermined curved shape as soon as the distal end portion ( 13 ) the optical fiber comprehensive distal end of the applicator ( 10 ) from the guide catheter ( 11 ) is pushed out. Applicator ( 10 ) according to claim 1, characterized in that the of a recess ( 7 ) affected portion of the cladding circumference at each longitudinal coordinate at most 20%, preferably at most 10%, of the shell circumference measures. Applicator ( 10 ) according to one of claims 1 to 2, characterized in that the recesses ( 7 ) through a plurality of spaced openings ( 4 ) or by a single elongated slot ( 9 ) in cladding ( 2 ) are formed. Applicator ( 10 ) according to claim 3, characterized in that the extent of the openings ( 4 ) in the axial direction of the optical fiber between 5 and 100 microns, preferably between 10 and 50 microns. Applicator ( 10 ) according to one of claims 3 to 4, characterized in that the distance between the distal end ( 12 ) of the optical fiber closest to and the distal end ( 12 ) of the optical fiber farthest ( 4 ) is between 1 and 100 mm, preferably between 10 and 40 mm. Applicator ( 10 ) according to one of claims 3 to 5, characterized in that each of the distal end ( 12 ) closer opening ( 4 ) has a larger cross-sectional area than a more remote opening ( 4 ) Applicator ( 10 ) according to one of claims 3 to 6, characterized in that the distances between each two adjacent openings in the direction of the distal end ( 12 ) of the optical fiber. Applicator ( 10 ) according to claim 3, characterized in that the slot width in the direction of the distal end ( 12 ) of the optical fiber changes in such a way that the power of the slot ( 9 ) emerging radiation per length element in the longitudinal direction of the slot is almost homogeneous. Applicator ( 10 ) according to one of claims 3 or 8, characterized in that the width of the slot ( 9 ) towards the distal end ( 12 ) of the optical fiber increases. Applicator ( 10 ) according to one of claims 3, 8 or 9, characterized in that the slot length is between 1 and 100 mm, preferably between 10 and 40 mm. Applicator ( 10 ) according to claim 3, characterized in that along the slot ( 9 ) there is a predetermined local Auskoppelgrad. Applicator ( 10 ) according to one of claims 3 to 7, characterized in that openings ( 4 ) each have a predetermined Auskoppelgrad. Applicator ( 10 ) according to one of claims 11 to 12, characterized in that the decoupling degree of at least one of the openings ( 4 ) or the local decoupling degree along the slot ( 9 ) is adjusted by the fact that for the optical fiber in the region of the opening ( 4 ) or slot ( 9 ) a certain cladding strength is provided and / or that the opening ( 4 ) or the slot ( 9 ) with a dielectric or metallic coating is provided. Applicator ( 10 ) according to one of claims 3 to 13, characterized in that the fiber core ( 1 ) in which at least one opening ( 4 ) or the slot ( 9 ) in Claddin ( 2 ) exposed area has a recess. Applicator ( 10 ) according to claim 14, characterized in that the decoupling degree of at least one of the openings ( 4 ) or the local decoupling degree along the slot ( 9 ) is adjusted through the recess in the fiber core. Applicator ( 10 ) according to one of claims 12 to 15, characterized in that the openings ( 4 ) are in a linear arrangement, and that the distances between adjacent openings and / or the size of the openings ( 4 ) and / or the decoupling degree of the openings ( 4 ) are selected such that from the openings ( 4 ) radiation field is formed such that the radiation in a direct contact with the applicator ( 10 ) body tissue is scattered so that, starting at a body tissue depth of 0.5 mm along the line-shaped arrangement of the openings ( 4 ) has a nearly homogeneous power density. Applicator ( 10 ) according to any one of claims 12 to 16, characterized in that the Auskoppelgrad of at least two of the openings (4) is in each case selected so that from the openings ( 4 ) emitted radiation has almost the same power. Applicator ( 10 ) according to one of claims 3 to 17, characterized in that the surface of the optical fiber in the region of at least one of the openings ( 4 ) or slot ( 9 ) is formed such that a desired radiation characteristic is generated. Applicator ( 10 ) according to one of claims 3 to 18, characterized in that the surface of the optical fiber in the region of at least one of the openings ( 4 ) or slot ( 9 ) is formed such that the exiting beams are collimated at least in the lateral direction. Applicator ( 10 ) according to one of claims 3 to 18, characterized in that the structure of the surface of the optical fiber in the region of at least one of the openings ( 4 ) or slot ( 9 ) is designed such that by refraction and / or scattering of the radiation whose exit angle is increased. Applicator ( 10 ) according to one of claims 3 to 20, characterized in that the surface of the optical fiber in the region of at least one of the openings ( 4 ) or slot ( 9 ) is formed such that the emission characteristic in the axial and lateral directions is the same. Applicator ( 10 ) according to one of claims 3 to 21, characterized in that the surface of the optical fiber in the region of at least one of the openings ( 4 ) or slot ( 9 ) has a lattice, groove or wavy structure. Applicator ( 10 ) according to one of claims 1 to 22, characterized in that it comprises a plastic sheath ( 3 ), into which the optical fiber and the elastic element ( 6 ) are embedded longitudinally to each other. Applicator ( 10 ) according to one of claims 3 to 23, characterized in that the arrangement of the openings ( 4 ) or slot ( 9 ) and with the applicator ( 10 ) after pushing out of the guide catheter ( 11 ), that a near-line or area-wide area without relative movement between applicator ( 10 ) and this area can be irradiated. Applicator ( 10 ) according to any one of claims 3 to 24, characterized in that that of the applicator ( 10 ) after pushing out of the guide catheter ( 11 ) is spiral or helical in shape and the openings ( 4 ) or the slot ( 9 ) are arranged along at least one full spiral or screw winding. Applicator ( 10 ) according to one of claims 1 to 25, characterized in that the recesses ( 7 ) are filled with a material which is transparent to the electromagnetic radiation, preferably a polymer, which has a higher refractive index than the fiber core (US Pat. 1 ). Applicator according to one of Claims 1 to 26, characterized in that the distal end surface of the optical fiber has a mirror coating ( 5 ) having. Method for producing an applicator ( 10 ), which is intended for the treatment of body tissue with electromagnetic radiation, wherein an elastic element ( 6 ) together with an optical fiber whose cladding ( 2 ), through which the fiber core is enclosed in its entire length, in its distal end portion (FIG. 13 ) is acted upon at a plurality of longitudinal coordinates in each case within exactly a portion of the cladding circumference from the outside with laser radiation such that by ablation in each case a defined recess ( 7 ) is formed with a depth of at least a major part of the cladding strength, can escape through the radiation from the optical fiber, in a Kunststoffum wrapping ( 3 ) and within this plastic envelope ( 3 ) into a guide catheter ( 11 ), and wherein the elastic element ( 6 ) is formed and preformed such that the distal end portion ( 13 ) the optical fiber assumes a predetermined curved shape as soon as the distal end portion ( 13 ) of the Lichtieitfaser comprehensive distal end of the applicator ( 10 ) from the guide catheter ( 11 ) is pushed out. Process for the preparation of an applicator ( 10 ) according to claim 28, characterized in that the ablation by means of the laser application a plurality of spaced openings ( 4 ) or a single elongated slot ( 9 ) in cladding ( 2 ) are formed. Process for the preparation of an applicator ( 10 ) according to claim 29, characterized in that when generating at least one opening ( 4 ) or slot ( 9 ) the ablation depth the strength of cladding ( 2 ), so that a recess is formed in the fiber core. Process for the preparation of an applicator ( 10 ) according to one of claims 29 to 30, characterized in that at least one of the openings ( 4 ) or slot ( 9 ) in cladding ( 2 ) of the optical fiber, the laser radiation is modulated such that the surface of the optical fiber in the region of the at least one opening ( 4 ) or slot ( 9 ) receives a lattice, groove or wavy structure.