GB2573981A

GB2573981A - Electrosurgical probe and apparatus

Info

Publication number: GB2573981A
Application number: GB1803302.7A
Authority: GB
Inventors: Davidge Matthew
Original assignee: Gyrus Medical Ltd
Current assignee: Gyrus Medical Ltd
Priority date: 2018-02-28
Filing date: 2018-02-28
Publication date: 2019-11-27
Anticipated expiration: 2038-02-28
Also published as: GB201803302D0; GB2573981B

Abstract

A probe 1 for an electrosurgical apparatus for coagulating tissue, the probe 1 comprising an elongated tube 2 through which an ionisable gas can be delivered. The tube 2 including a longitudinally extending lumen 3 surrounded by a circumferential wall 5. The wall 5 further has at least two apertures 6, 7 provided therein, the apertures 6, 7 being spaced one from another along the longitudinal axis of the tube 2, and also being oriented in different radial directions around the tube 2. An electrode 11 for ionising the ionisable gas prior to the gas exiting the apertures 6, 7 is also provided, the electrode 11 being longitudinally movable within the tube 3 so as to be selectively positioned adjacent one of the apertures 6, 7. The probe also includes a supply aperture 9 through which the ionisable gas can be supplied to the lumen 3. In a preferred embodiment the electrode 11 is connected to a moveable baffle 13 which serves to obstruct the lumen 3 so as to prevent the ionisable gas flowing further along the lumen 3 than required.

Description

This invention relates to an electrosurgical probe and apparatus, and in particular to the non-contact coagulation of tissue using an ionisable gas such as argon. Argon beam coagulators have been known for many years, and examples are given in US patents 4,040,426, 5,720,745, 6,039,736 and 6,197,026. The first example is an end-effect instrument, in which the ionised gas exits through the end of the instrument, while the latter two examples are directed at side-effect instruments, in which the ionised gas exits the instrument though an aperture in the side of the instrument. Such instruments are often referred to as APC instruments (Argon Plasma Coagulation).

The invention attempts to provide an instrument which is more versatile than any of the instruments in the prior art, and accordingly resides in an electrosurgical probe for an electrosurgical apparatus for coagulating tissue, the probe comprising:

an elongated tube having a proximal end and a distal end and defining a longitudinal axis therebetween, the tube including a longitudinally extending lumen surrounded by a circumferential wall, the wall having at least a first aperture and a second aperture, the first and second apertures being spaced one from another along the longitudinal axis, the first and second apertures also being oriented in different radial directions around the tube, the probe also including a supply aperture through which an ionisable gas can be supplied to the lumen to flow out of the tube through one of the first and second apertures, and an electrode for ionising the ionisable gas prior to the gas exiting the first and second apertures, the electrode being longitudinally movable within the tube so as to be selectively positioned adjacent the first aperture or adjacent the second aperture.

Previous side-effect APC instruments have had a fixed side aperture or array of apertures, such that the direction of the tissue effect is unchangeable. The present invention provides a way of changing the direction of the tissue effect, such that the instrument can selectively treat tissue in different lateral directions. The first and second apertures provide two different directions of operation, which can be selectively chosen by the user of the instrument.

The tube preferably includes a baffle capable of obstructing the lumen so as to prevent the ionisable gas flowing further along the lumen. The baffle prevents the gas from flowing further along the tube and urges it out of the side apertures. Conveniently, the baffle is longitudinally movable with respect to the lumen so as to assume at least two different longitudinal positions within the lumen. The baffle is preferably longitudinally movable with respect to the lumen so as to assume at least a first position distal of the first aperture and proximal of the second aperture, and a second position distal of the second aperture. In this way, the baffle can be moved to cause the gas to exit via a selected one of the first and second apertures.

The baffle is conveniently in the form of a piston longitudinally slideable within the lumen. The baffle is conceivably connected to the electrode such that the electrode and the baffle move together within the lumen. In this way, as the electrode is moved so as to be located adjacent one of the side apertures, the baffle is automatically located so as to urge the gas to exit that same aperture.

According to one convenient arrangement, the tube includes at least three apertures, each being spaced one from another along the longitudinal axis, and each being oriented in different radial directions around the tube. Preferably, the tube includes a baffle capable of obstructing the lumen so as to prevent the ionisable gas flowing further along the lumen, the baffle being longitudinally movable with respect to the lumen so as to assume at least a first position distal of the first aperture and proximal of the second aperture, a second position distal of the second aperture and proximal of the third aperture, and a third position distal of the third aperture. By positioning the baffle in one of the three selected positions, the gas can by urged to exit the first aperture, the second aperture or the third aperture as desired. This provides three different directions of operation, which can be selectively chosen by the user of the instrument, without needing to re-orient the probe within the patient.

The invention further resides in an electrosurgical apparatus for coagulating tissue, comprising:

an elongated tube having a proximal end and a distal end and defining a longitudinal axis therebetween, the tube including a longitudinally extending lumen surrounded by a circumferential wall, the wall having at least a first aperture and a second aperture, the first and second apertures being spaced one from another along the longitudinal axis, the first and second apertures also being oriented in different radial directions around the tube, a source for supplying ionisable gas to the lumen such that it can flow out of the tube through one of the first and second apertures, an electrode for ionising the ionisable gas prior to the gas exiting the first and second apertures, an electrosurgical generator for supplying electrosurgical energy to the electrode, and actuation means for moving the electrode longitudinally within the tube so as to be selectively positioned adjacent the first aperture or adjacent the second aperture.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic partly transparent view of an electrosurgical probe in accordance with the present invention,

Figure 2 is a schematic partly transparent view of the electrosurgical probe of Figure 1, with the electrode assembly in a second position,

Figure 3 is a schematic partly transparent view of the electrosurgical probe of Figure 1, with the electrode assembly in a third position,

Figure 4 is a transparent plan view of the electrosurgical probe of Figures 1 to 3,

Figure 5 is a schematic sectional view of the actuator of an electrosurgical instrument containing the probe of Figures 1 to 4, with the actuator shown in a retracted position, and

Figure 6 is a schematic sectional view of the actuator of Figure 5, shown in an advanced position.

Referring to Figure 1, an APC probe is shown generally at 1, and comprises an elongate tube 2 with an internal lumen 3 closed off by an end cap 4. The tube has a cylindrical side wall 5 having a first side aperture 6 extending therethrough at a first longitudinal position and facing in a first radial direction. A second side aperture 7 extends through the side wall 5 at a second longitudinal position and faces in a second radial direction. A third side aperture 8 extends through the side wall 5 at a third longitudinal position and faces in a third radial direction.

A supply aperture 9 is present at the proximal end of the tube 2 such that an ionisable gas such as argon can be fed into the lumen 3, to exit through one of the side apertures 6, 7 or 8. Slideably present within the lumen 3 is an electrode assembly 10, the electrode assembly comprising a wire electrode 11 exposed towards its distal end but otherwise covered by an insulating sheath 12. At the distal end of the electrode assembly 10 is a baffle in the form of a piston 13 slideably contained within the lumen

3. The piston 13 may or may not form a gas-tight seal within the lumen 3, but either way it blocks the lumen sufficiently to prevent the majority of the argon gas from passing.

In Figure 1, the electrode assembly 10 is located in a first longitudinal position, such that the electrode 11 is located adjacent the first side aperture 6. The argon gas supplied to the lumen is ionised by the electrosurgical energy supplied to the electrode 11 by an electrosurgical generator (not shown), converting the argon into a plasma, which then exits the tube through the first aperture 6 in a first radial direction. The piston 13 prevents the gas travelling further down the lumen 3, such that no plasma exits through the second or third side apertures 7 or 8.

In Figure 2, the electrode assembly 10 has been advanced to its second position, such that the electrode 11 is adjacent the second aperture 7. The electrode 11 converts the argon gas to a plasma, which exits through the aperture 7 in a different radial direction to that of aperture 6. In this way, the user can switch between treating tissue located in a radial direction associated with aperture 6, and treating tissue in a radial direction associated with aperture 7, all without needing to re-orient the probe 1.

The piston 13 prevents the argon gas travelling further down the lumen 3, such that no plasma exits through the side aperture 8. Whereas some small amount of nonionised argon gas can exit through side aperture 6, when the electrode assembly is in its second position as shown in Figure 2 the distance between the aperture 6 and the electrode 11 is great enough that this argon gas will not be ionised, and so tissue located near aperture 6 will not be affected. The insulating sheath 12 minimises the exposed area of the electrode 11, such that only gas in the immediate vicinity of the electrode is ionised to form a plasma.

Figure 3 shows the electrode assembly 10 located in its third position, in which it is adjacent the third side aperture 8. As before, the electrode 11 converts the argon gas to a plasma, which exits through the aperture 8 in a further different radial direction to that of apertures 6 or 7. Thus, the user can switch to treating tissue located in a third radial direction, again without needing to re-orient the probe 1. As before, the distance between the electrode 11 and the small amount of argon gas exiting through apertures 6 or 7 means that the gas will not be ionised, and hence will not create any tissue effect with respect to tissue in these other orientations.

Figure 4 shows the different radial directions for the side apertures 6, 7 & 8, being radially spaced each at a 120 degree angle one to another. In this way, by the selection of one or other of the apertures 6, 7 & 8, tissue can be treated at whatever position with respect to the probe 1, without needing to re-orient the probe.

Figure 5 shows an actuator 20 used to move the electrode assembly 10 between its first, second and third positions. The actuator 20 comprises a first part 13 and a second part 14, the first and second parts being slideable with respect to one another. The first part 13 is connected to an elongate flexible shaft 15, the tube 2 being attached at the distal end of the shaft 15. The second part 14 is attached to the electrode assembly 10, via an elongate conductive wire 16. With the actuator in the position shown in Figure 5, with the second part 14 separated from the first part 13, the electrode assembly 10 is withdrawn such that it is in its first position as illustrated in Figure 1. This is the position for using the instrument to produce plasma through side aperture 6.

To change the orientation of the tissue treatment effect, the second part 14 is advanced towards the first part 13, thereby advancing the electrode assembly 10 to its second position. Finally, to advance the electrode assembly 10 to its third position, the second part 14 is advanced such that it is adjacent the first part 13, as shown in Figure

6. This advances the electrode assembly to the position shown in Figure 3, where the plasma emerges through side aperture 8. By moving the second part 14 towards and away from the first part 13, the electrode assembly can be advanced and retracted, in order to vary the aperture through which the plasma emerges, and hence the direction of tissue treatment. All this can be achieved merely by moving the actuator 20, and without rotating the probe 1.

Those skilled in the art will appreciate that other constructions can be envisaged without departing from the scope of the present invention. For example, different side apertures can be envisaged, with greater or lesser differences in their radial position.

Other designs of baffle can be employed instead of the piston 13. Whichever alternatives are employed, the longitudinal movement of an electrode assembly changes which side aperture is used to dispense the ionised gas, and hence the angle at which the tissue is treated.

Claims

1. A probe for an electrosurgical apparatus for coagulating tissue, the probe comprising:

2. A probe according to claim 1, wherein the tube includes a baffle capable of obstructing the lumen so as to prevent the ionisable gas flowing further along the lumen.

3. A probe according to claim 2, wherein the baffle is longitudinally movable with respect to the lumen so as to assume at least two different longitudinal positions within the lumen.

4. A probe according to claim 3, wherein the baffle is longitudinally movable with respect to the lumen so as to assume at least a first position distal of the first aperture and proximal of the second aperture, and a second position distal of the second aperture.

5.

A probe according to any of claims 2 to 4, wherein the baffle is in the form of a piston longitudinally slideable within the lumen.

6. A probe according to any of claims 2 to 5, wherein the baffle is connected to the electrode such that the electrode and the baffle move together within the lumen.

7. A probe according to any preceding claim, wherein the tube includes at least three apertures, each being spaced one from another along the longitudinal axis, and each being oriented in different radial directions around the tube.

8. Apparatus according to claim 7, wherein the tube includes a baffle capable of obstructing the lumen so as to prevent the ionisable gas flowing further along the lumen, the baffle being longitudinally movable with respect to the lumen so as to assume at least a first position distal of the first aperture and proximal of the second aperture, a second position distal of the second aperture and proximal of the third aperture, and a third position distal of the third aperture.

9. An electrosurgical apparatus for coagulating tissue, comprising: