WO2017005830A1 - Electrosurgical instrument for argon-plasma coagulation, and a method for operating same - Google Patents

Abstract

The invention relates to an electrosurgical instrument for argon-plasma coagulation, and to a method for operating such an electrosurgical instrument. The electrosurgical instrument comprises an instrument shaft having an inner cavity (111, 211, 311) and a distal end section (120, 220, 320, 420) with a distal opening (130, 230, 330, 430), and an electrode (140, 240, 340) arranged in said cavity, wherein a shape and/or diameter of the distal opening is made to be variable.

Description

 Electrosurgical instrument for argon plasma coagulation and method of operation

The invention relates to an electrosurgical instrument for argon plasma coagulation and to a method for operating such an electrosurgical instrument.

Argon plasma coagulation (also abbreviated to argon plasma coagulation) is a procedure of monopolar radiofrequency surgery and is used in both endoscopic and conventional surgery. In argon plasma coagulation, electrical energy in the form of a radio frequency (RF) current is transferred by ionized, and thus electrically conductive, argon gas to the tissue to be coagulated. The argon-plasma coagulation is thus a contactless process. The electrical energy in the form of an HF current is transmitted by means of a plasma jet in plasma channels, so that the tissue hit by this plasma jet is thermally devitalized up to vaporized. The depth of penetration of the thermal effect is limited so that deeper tissue layers are not detected and therefore no damage. One advantage of plasma coagulation over laser coagulation lies in this deep-limited mode of action. Another advantage of the plasma coagulation results from the contactless application of the high-frequency current, since in this way no tissue can adhere to the electrode. The desired effect on the tissue to be treated is usually adjusted via the power of the radio frequency (RF) generator, the argon gas flow and the distance of the electrosurgical instrument to the tissue surface. Excessive energy input into the tissue can lead to unwanted, excessive tissue damage, such as carbonization of the tissue, or can result in heavy smoke development. For example, too little energy input into the tissue can lead to inadequate treatment. The energy input in existing solutions depends mainly on the experience of the respective surgeon and its handling of the electrosurgical instrument and electrosurgical system.

It is therefore an object of the present invention to provide an electrosurgical instrument for argon plasma coagulation and a method of operating such an instrument, which are improved over existing solutions and / or reduce or eliminate one or more of the mentioned disadvantages. In particular, it is an object of the present invention to provide an electrosurgical instrument for argon plasma coagulation and a method for operating such an instrument, which improve and / or facilitate the adjustability of the energy input into the tissue.

This object is achieved by an electrosurgical instrument for argon plasma coagulation, comprising an instrument shaft having an internal cavity and a distal end portion having a distal opening, and an electrode disposed in the cavity, wherein a shape and diameter of the distal opening is designed variable.

Electrosurgical instruments for argon plasma coagulation may also be referred to as argon plasma coagulation applicators or probes or, briefly, as APC instruments, applicators or probes.

An electrosurgical instrument for argon plasma coagulation comprises a hollow, usually elongate instrument shaft having a longitudinal axis, wherein a distal opening is formed at a distal end portion. In the inner cavity of the instrument shaft, an electrode is arranged. Preferably, this electrode does not project beyond the distal opening in the axial direction, so that contact of the electrode with the tissue is avoided, even if the instrument shaft, in particular the edge of its distal opening, should once come into contact with the tissue. At a proximal end of the electrosurgical instrument, in particular the instrument shaft, a gas connection and a high-frequency connection are preferably present. The high-frequency connection is preferably used to connect the electrode to a high-frequency generator. The gas connection serves preferably to supply ionized argon gas into the internal cavity of the instrument shaft, which can emerge from the distal opening in the form of a plasma jet or in plasma channels.

While it is generally provided in existing solutions in existing solutions that the distal opening has a diameter tapered with respect to the instrument shaft, so that the distal end section has the shape of a nozzle, it is provided here that the shape and / or the diameter the distal opening are designed variable. In this way, in addition to the known adjustment parameters, an additional parameter is created, which influences the energy input into the tissue. An enlargement of the diameter or the Ouerschnittsform the distal opening allows the exit of a plasma jet with a correspondingly larger diameter or larger Ouerschnittsform and thus correspondingly more plasma channels, whereas a distal opening with a smaller diameter or small Ouerschnittsform only the passage of a plasma jet with a correspondingly smaller diameter or smaller Ouerschnittsform and a smaller number of plasma channels allowed. One way of variably designing the distal opening is to provide various end pieces for the electrosurgical instrument, from which the user can select one immediately prior to application and place it on the electrosurgical instrument.

A change in the shape and / or orientation of the distal end section may in particular be a change in the angle of inclination and / or a curvature and / or a curvature profile of a lateral surface of the distal end section.

Preferably, the electrosurgical instrument, in particular the distal end portion, is designed and arranged such that the shape and / or the diameter of the distal opening can be changed by a user and preferably also fixed in a desired position or shape and / or diameter size , In this way, a user may change the shape and / or diameter of the distal opening prior to and / or during treatment in order to maintain the same in the desired shape and / or size during (further) treatment If necessary, a further adjustment or change is displayed. Alternatively or additionally, it can also be provided that an automatic change in the shape and / or diameter of the distal opening is made on the electrosurgical instrument and / or by a control unit on an electrosurgical system if a measured value, for example a temperature measurement, is a measured value for the Impedance of the tissue to be treated, a voltage, current or power reading of the generator or a measurement of the composition of the resulting during the treatment of flue gas enters a predetermined range of values or leaves a predetermined range of values. In this way, unwanted tissue effects can be prevented or reduced by the energy input is timely and preferably adjusted automatically by a change in the shape and / or the diameter of the distal opening or a user is warned in good time.

In a preferred embodiment, it is provided that a shape and / or orientation of the distal end portion is configured variably. It is furthermore particularly preferred that the distal end section is designed to be variable such that a change in the distal end section causes a change in the shape and / or the diameter of the distal opening.

The variability or changeability of the shape and / or the diameter of the distal opening can preferably take place in that the distal end section is variable or changeable, in particular with respect to its shape and / or orientation. Since the distal opening is preferably formed by or surrounded by the end of the distal end portion, altering the shape and / or orientation of the distal end portion typically also automatically causes a change in the shape and / or diameter of the distal opening.

Furthermore, an embodiment is preferred in which the electrode is arranged and formed such that a change in the position of the electrode relative to the distal end portion causes a change of the distal end portion, in particular its shape and / or orientation. The electrode may, for example, be fastened to the instrument shaft, in particular to the distal end section, for example via a support structure. A change in the position of the electrode relative to the distal end portion may, for example, be a relative displacement, in particular in the axial direction. In particular, it is preferable that a retraction of the electrode in the proximal direction can increase the diameter of the distal opening and / or a Displacement of the electrode in the distal direction can cause a reduction in the diameter of the distal opening. This can preferably be done by changing the angle of inclination and / or the curvature of the outer circumferential surface of the distal end portion. Further, an embodiment is preferred, which is characterized by an activation element, which is designed and arranged to effect a change of the distal end portion. Preferably, the activation element is operable from a proximal end of the instrument. The activation element can also be actuated by a handpiece and / or by a generator and / or another part of an electrochemical system for operating the electrosurgical instrument.

It is particularly preferred that the activation element is arranged to be movable relative to the distal end section, in particular displaceable along a longitudinal axis and / or rotatable about a longitudinal axis. For example, the activation element can be connected to the instrument shaft via a thread and / or can be actuated by a thread.

In an exemplary embodiment, the activation element may be formed as a sleeve. Furthermore, it may be preferred that the activation element runs coaxially inside or outside the instrument shaft. In particular, it is further preferred that the activation element is connected to the instrument shaft, preferably the distal end section.

In a further preferred embodiment it is provided that the distal end portion is divided several times in the circumferential direction. Preferably, the distal end portion has a plurality of fins, which may be formed in particular curved. It is particularly preferred that the lamellae overlap in the circumferential direction at least in sections.

The formation of the distal end portion in a multiple subdivision in the circumferential direction, in particular with a plurality of partially overlapping lamellae, represents a particularly preferred embodiment, which the change of the distal end portion of a taper to the distal end with a distal opening with a small Diameter toward an extension to the distal end to a distal opening with a large diameter realized in a particularly advantageous and efficient way. Especially in combination with an activating element ment, which is connected to the distal end portion and movably arranged relative to the distal end portion, in particular displaceable along a longitudinal axis and / or rotatable about a longitudinal axis, a transition of the, preferably curved, lamellae from a position with a small diameter distal opening to achieve a position with a large-diameter distal opening particularly easily and efficiently.

According to a further aspect of the invention, the object mentioned at the outset is achieved by an electrosurgical system for argon plasma coagulation, comprising a high-frequency generator, an argon gas source, and a previously described electrosurgical instrument. Preferably, the electrosurgical system further comprises a control unit which is designed to issue a warning in dependence on a measured value and / or to make a change in the shape and / or the diameter of the distal opening.

According to a further aspect of the invention, the object mentioned is achieved by a method for operating an electrosurgical instrument for argon plasma coagulation, comprising: providing a previously described electrosurgical instrument for argon plasma coagulation, changing the shape and / or the diameter of the distal opening. Preferably, the alteration of the diameter of the distal opening can be carried out automatically after exceeding a limit value of a measured value and / or a warning can be output when a limit value of a measured value is exceeded.

The system and the method are particularly suitable for use or for operating a previously described electrosurgical instrument and its training. The system and method and their respective further developments preferably have features or method steps which make them particularly suitable for use with an electrosurgical instrument according to the invention and its further developments. For the advantages, embodiments and details of execution of the system and the method and their respective possible developments, reference is made to the preceding description of the corresponding features of the electrosurgical instrument.

A preferred embodiment of the invention will be described by way of example with reference to the accompanying drawings. Show it: Fig. 1: an electrosurgical instrument for argon plasma coagulation according to the prior art;

2a to c are schematic representations in transverse and longitudinal section of an exemplary embodiment of a distal end portion of an electrosurgical instrument according to the invention with a large diameter (a), medium diameter (b) and small diameter (c) distal opening;

3a and b: schematic representations of a further exemplary embodiment of a distal end section of an electrosurgical instrument according to the invention in longitudinal section with the distal opening of large diameter (a) and of small diameter (b);

4 shows a schematic representation of a further possible embodiment of a distal end section of an electrosurgical instrument according to the invention; and

Fig. 5: a schematic representation (side view) of another possible

 Embodiment of a distal end portion of an electrosurgical instrument according to the invention.

FIG. 1 shows a prior art electrosurgical instrument 1 for argon plasma coagulation, which may also be referred to as an APC probe, comprising an elongated instrument shaft 10 having an inner cavity 11 and a distal end portion 20 having a distal opening 30. In the cavity 1 1, an electrode 40 is arranged, from which plasma channels 4 in the argon gas 3 extend to the surface of the tissue 2 to be treated. In the prior art example shown in FIG. 1, the distal end portion 20 is not variable but has a defined, fixed geometry so that the shape and diameter of the distal opening 30 are fixed.

A distal end section 120 with a distal opening 130 of an exemplary embodiment of an electrosurgical instrument according to the invention is shown schematically in FIGS. 2a to c, respectively, at the top in cross-section and at the bottom in longitudinal section. In the inner cavity 1 1 1 of the distal end portion 120, an electrode 140 is arranged, which is connected via an electrically non-conductive support structure 1 12 with the distal end portion 120. With the arrow A, the flow direction of the ionized, argon gas is indicated. 2b, the lateral surface of the end portion 120 extends substantially parallel to the electrode 140 and to a longitudinal axis of the distal end portion 120 which is preferably identical to a longitudinal axis of an instrument shaft and the electrosurgical instrument as a whole. The diameter of the distal opening 130 thus substantially corresponds to the diameter of the inner cavity 1 1 1.

If now the electrode 140 is displaced in the proximal direction as shown in Fig. 2a (in Fig. 2a to the left, which is indicated by the displacement of the dashed extension of the support structure 1 12 relative to the mark x / 2), this leads to a change the inclination and thus the orientation of the distal end portion 120, in particular its lateral surface, so that the diameter of the distal opening 130 is enlarged relative to the situation shown in Fig. 2b.

In the situation illustrated in FIG. 2 c, the electrode 140 is displaced in the axial direction distally relative to the situation illustrated in FIG. 2 b, which is displaced to the right by the dashed extension of the support structure 1 12 which is opposite to the position x / 2 in FIG. 2 c is displayed. This distal displacement of the electrode 140 results in a change in the orientation of the lateral surface of the distal end portion 120 in the reverse direction to the orientation shown in FIG. 2a, so that the distal opening 130 has a smaller diameter in the situation illustrated in FIG. 2c than in the situations shown in Figs. 2a and 2b.

A further possible embodiment of a variable distal end section 220 of an exemplary embodiment of an electrosurgical instrument according to the invention is shown schematically and by way of example in FIGS. 3 a and 3 b in longitudinal section. Again, an electrode 240 is disposed in an internal cavity 21 1 of an instrument shaft and connected to the distal end portion 220 via a support structure 212. With the arrow A, the flow direction of the ionized, argon gas is indicated.

A displacement of the electrode in the proximal direction, shown here in Fig. 3a, leads to a change in the shape and orientation of the distal end portion 220 such that the diameter of the distal opening 230 is increased, as can be seen in Fig. 3a. In contrast, a displacement of the electrode 240 in the distal direction leads to a change in the shape and orientation of the distal end portion 220 in an opposite direction to the situation shown in Fig. 3a, so that the Durchstr. reduced diameter of the distal opening 230 with respect to the situation shown in Fig. 3a.

FIG. 4 shows schematically and by way of example another possible embodiment of a distal end section 320 of an embodiment of an inventive electrosurgical instrument. Also in Fig. 4, an electrode 340 is disposed in an internal cavity 31 1 of an instrument shaft. In the variant shown in FIG. 4, an activation element 350 in the form of a sleeve is arranged coaxially outside the instrument shaft or the distal end section 320 and connected to the distal end section 320 such that an axial displacement of the activation element 350 (in FIG. 4 via the double arrow indicated) causes a corresponding axial displacement of the distal end portion 320. This is particularly preferred when the distal end portion 320 is divided several times in the circumferential direction and has a plurality of, preferably curved, lamellae which overlap in the circumferential direction at least in sections. In this way, by a, preferably small, axial displacement of these lamellae of the distal end portion 320, a change in the shape and orientation of the distal end portion 320 between the indicated with the broken lines in Fig. 4 forms of the distal end portion 320 of the large and small diameter distal aperture 330, since in this way the lamellae of the distal end portion 320 relative to the instrument shaft can change position accordingly.

FIG. 5 diagrammatically and by way of example shows another possible embodiment of a distal end section 420 of an embodiment of an inventive electrosurgical instrument in a side view. The distal end section 420 is divided several times in the circumferential direction and has a plurality of slightly curved louvers 421, wherein the louvers 421 overlap in the circumferential direction at least in sections. In the situation illustrated in FIG. 5, the distal opening 430 has a small diameter. Preferably, the distal end portion 420 is also provided with an activating member (not shown) which can move the slats 421 from the small distal opening 430 position shown in FIG. 5 to a larger distal opening position and move it in reverse ,

Due to the variability of the diameter and / or the shape of the distal opening of the electrosurgical instrument for argon plasma coagulation, a further adjustable parameter can thus be made available to the user or can be provided in FIG an electrosurgical system, preferably automatic control, are made possible, which in addition to or instead of existing parameters, the energy input before and / or can change during a treatment in a desired and / or required amount. In this way, a treatment can be improved, in particular undesired tissue damage can be avoided, the treatment can be carried out more precisely and effectively and thus a better overall treatment result can be achieved.

The variable configuration of the distal end portion of the instrument can further serve to facilitate the introduction of the instrument, for example in the working channel of an endoscope or in a trocar cannula.

Claims

Electrosurgical instrument for argon plasma coagulation comprising an instrument shaft having an inner cavity (1 1 1, 21 1, 31 1) and a distal end portion (120, 220, 320, 420) having a distal opening (130, 230, 330, 430), and an electrode (140, 240, 340) disposed in the cavity, wherein a shape and / or a diameter of the distal opening is configured variable, and wherein an activation element (350) is formed and arranged to cause a change of the distal end portion (120, 220, 320, 420). Electrosurgical instrument according to at least claim 1, characterized in that a shape and / or orientation of the distal End portion (120, 220, 320, 420) is configured variable. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the distal end portion (120, 220, 320, 420) is variably configured such that a change in the distal end portion causes a change in the shape and / or diameter of the distal opening (130, 230, 330, 430). Electrosurgical instrument according to at least one of the preceding claims, characterized in that the electrode (140, 240, 340) is arranged and formed such that a change in the position of the electrode relative to the distal end portion causes a change of the distal end portion (120, 220, 320, 420), in particular its shape and / or orientation. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) is operable from a proximal end of the instrument. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) is arranged to be movable relative to the distal end section (120, 220, 320, 420), in particular displaceable along a longitudinal axis and / or rotatable about a longitudinal axis. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) connected via a Ge thread with the instrument shaft and / or can be actuated by a thread. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) is designed as a sleeve. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) extends coaxially inside or outside the instrument shaft. Electrosurgical instrument according to at least one of the preceding claims, characterized in that the activation element (350) is connected to the instrument shaft, preferably the distal end portion (120, 220, 320, 420). Electrosurgical instrument according to at least one of the preceding claims, characterized in that the distal end portion (120, 220, 320, 420) is divided multiple times in the circumferential direction. 12. electrosurgical instrument according to at least one of the preceding claims,  characterized in that the distal end portion (420) has a plurality of, preferably curved, blades (421), wherein the blades preferably overlap in the circumferential direction at least in sections. 13. An electrosurgical system for argon plasma coagulation comprising a high frequency generator,  - an argon gas source, and  - An electrosurgical instrument according to at least one of the preceding claims. 14. A method of operating an electrosurgical instrument for argon plasma coagulation,  full:  Providing an electrosurgical instrument for argon plasma coagulation according to at least one of the preceding claims 1-13,  - Changing the shape and / or the diameter of the distal opening (130, 230, 330, 430).