WO1998055036A1

WO1998055036A1 - Procedure for removal of highly vascularised tissue

Info

Publication number: WO1998055036A1
Application number: PCT/AU1998/000328
Authority: WO
Inventors: Kanag Baska
Original assignee: Nathan Surgicals Pty. Ltd.
Priority date: 1997-06-04
Filing date: 1998-05-07
Publication date: 1998-12-10
Also published as: AUPO716597A0

Abstract

A method for servering highly vascularised tissue bodies such as tonsils and haemorrhoids whilst at the same time at least partly cauterising any severed blood vessels. Severing of the highly vascularised tissue body is achieved using a snare (10) which can act as an electrode (14) whereby the snare is tightened around the highly vascularised tissue body and an electric current applied to it.

Description

Procedure for removal of highly vascularised tissue Technical Field

The present invention relates to a procedure for the removal of the palatine tonsils of a patient. More particularly the invention relates to the use of an electro-surgical device in a new way to bring about excision of the palatine tonsils and other highly vascularised tissues. Background Art

It is known to use monopolar or bipolar electro-surgery to cut and coagulate bodily tissue. This typically involves the use of radio frequency current that flows from a generator to an active electrode that delivers the current to the patient. The resistance to the current, provided by the patient's tissue and/or the air between the active electrode and the tissue, produces the heat that is necessary for the surgical effect. The RF current flows from the active electrode through the patients body to the return electrode, which recovers the current and returns it to the generator.

Such electro-surgery has been used for a variety of surgical procedures for the cutting of tissue and the cauterising of blood vessels. It has also been used in association with a snare to sever small lightly vascularised tissues, such as polyps in the intestinal tract, from some underlying tissue. The palatine tonsils are a pair of masses of lymphoid tissue situated in the tonsillar fossa in each lateral wall of the oropharynx. Their projecting medial surfaces are each free and covered by a mucus membrane , while their lateral surfaces are each covered by a capsule that separates it from the superior constrictor muscle of the pharynx. Removal of each palatine tonsil is relatively easy because of the rounded lateral aspect of the gland presented by the capsule. The tonsil is however loosely attached to underlying tissues and is richly supplied with blood vessels.

To remove a tonsil the mucus membrane covering the tonsil is typically cut and the tonsil loosened from the underlying tissue. A snare is then placed around the tonsil and drawn tight to cut the vessels and other tissues that are holding the tonsil to the underlying tissue. The blood vessels and connective tissue are ruptured by the snare as it is drawn tight. The ruptured blood vessels obviously bleed profusely and steps must be taken to stop the flow of blood resulting from the operation. To do this pressure is typically applied initially to the area of bleeding. The cut blood vessels are then sought by the surgeon and individually cauterised or otherwise ligated.

The major problem confronting a surgeon in carrying out a tonsillectomy is the suppression of bleeding after the tonsil has actually been removed. This is typically done by suture, ligature or electrodessication. It may be necessary to resort to further measures including cautery or by one of several methods of applying pressure . In severe cases it may be necessary to use coagulant chemicals and/or vasoconstrictors to stop the bleeding. It is to be noted that in those tonsillectomies where electro-surgical procedures have been used they have been used only for the purpose of stopping blood flow from the ruptured blood vessels after the tonsil has been removed.

A similar problem arises with other highly vascularised tissues such as haemorrhoids. Haemorrhoids are distended veins associated with the anus. They may be internal with respect to the anal orifice or they may be external to it. External haemorrhoids are covered with skin while internal haemorrhoids are covered with mucus membrane. While haemorrhoids are common they do not require treatment until they become enlarged and symptomatic. Treatment may be by medication and dietary modification or by operative intervention. In the latter case the haemorrhoids may be treated by injection of an irritant chemical into the loose areolar tissue above the internal haemorrhoid; by rubber band ligation; by cryosurgery; or by surgical excision. Commonly used methods of surgically excising haemorrhoids involve cutting the mucous membrane covering the haemorrhoids, separating the vascular tissue from the surrounding tissue such that the vascular tissue is still attached to the anal wall only by means of its blood vessels. The blood vessels may then be ligated by means of a stitch before being severed. This reduces the problem of loss of blood. Unfortunately this method of stitch ligature cannot be employed for the removal of a tonsil. Accordingly, a reliable means of preventing excessive blood loss is required. Disclosure of Invention

The present invention is directed to a procedure for the removal of a highly vascularised tissue, such as a palatine tonsil or haemorrhoid, from a patient in which the vascularised tissue is loosened from its surrounding tissue and the blood vessels and other tissue connecting the vascularised tissue to the underlying tissue is severed by electro-surgery while simultaneously at least partly cauterising the blood vessels so severed.

In the tonsillectomy procedure according to the present invention the blood vessels are cut and cauterised at the one time as compared with the conventional procedure in which the vessels are cut and then cauterised in a second step. As the vessels can often be drawn back into the underlying tissue due to their inherent elasticity it can be difficult for a surgeon to find the vessels to bring about the cauterisation of the vessels after they have been severed. The arrangement according to the present invention has the advantage that the blood vessels are cauterised as they are cut and the risk of excessive bleeding is substantially reduced. The fact that the surgeon does not have to search among the surrounding muscle fibres to find the vessels that require cauterisation means that there is far less muscle damage caused by the operation than would otherwise be the case. There is a far lower incidence of blood loss by the patient and less vomiting of blood containing stomach contents. The patient therefor is more comfortable and recovers more quickly than with conventional tonsillectomy. There is also less need for analgesia and patient discharge occurs more quickly.

The tonsillectomy procedure according to the present invention is preferably carried out by loosening the tonsil from the underlying tissue in the traditional manner and then placing around the tonsil a snare that can act as an active electrode in a monopolar electro-surgical system or as both electrodes in a bipolar system. The snare is then drawn tight around the tissue and blood vessels and a current applied to the electrode(s). Further tightening of the snare will cut through the blood vessels and other tissue and cause coagulation and cauterisation of the blood vessels as they are severed.

Operative procedures according to the present invention on other highly vascularised tissues such as haemorrhoids follow the same general procedure as has been described in respect of tonsillectomy. The surprising finding in the present invention is that such highly vascularised tissue as the tonsil and the haemorrhoid can be removed with a substantial reduction in blood loss by the use of the procedure according to the present invention. It has been found that it is only necessary to apply to the snare electrical power at a level that is suitable for typical coagulation procedures rather than the higher powers that are used for typical surgical cutting. Brief Description of Drawings

The following description of a preferred embodiment of the present invention is provided as an example of the invention and is described with reference to the accompanying drawings in which:- Figure 1 a side elevational view of one side of an electro-surgical snare for use in the procedure according to the present invention,

Figure 2 is a side elevational view of the other side of the electro- surgical snare of fig. 1,

Figure 3 is a diagrammatic representation of a first stage of a tonsillectomy procedure according to the present invention,

Figure 4 is a diagrammatic representation of a second stage of a tonsillectomy procedure according to the present invention, and

Figure 5 is a diagrammatic representation of a third stage of a tonsillectomy procedure according to the present invention. Best Mode for Carrying Out the Invention

The procedure according to the present invention preferably uses an electro-surgical snare such as that shown in figs. 1 and 2. The snare 10 comprises a handle 11, an elongate tube 12 extending from the handle 11, a slide 13 mounted slidably on the handle 11. and an electrode 14 connected at one end to the slide 13 and extending along the tube 12 to emerge at its free end.

The handle 11 is formed of an electrically insulating material such as a synthetic plastics material. It comprises a grippable portion 15, that can be gripped by a user, and an elongate portion 16 extending laterally from the top of the grippable portion in the manner of the barrel of a pistol. A slot 17 is provided longitudinally of the elongate portion 16. The slide 13 is positioned on the handle 11 so that it is slidable along the handle 11. The slide 13 projects below the elongate portion 16 of the handle 11 such that a loop 18 may be contacted by a finger of a user gripping the handle 11. The use may thus move the slide 13 along the handle while the handle 11 is being gripped.

The elongate tube 12 is connected to the end of the elongate portion 16 distal to the grippable portion 15. It is formed of an electrically non- conductive material that is sufficiently stiff to contain and deform the electrode in a manner that will be described later in this specification. The electrode 14 comprises an elongate wire 19 that is provided at its free end with a doubled over section of spring wire 21. The wire 19 is coimected at one end to the slide 13 so that movement of the slide causes corresponding movement of the electrode 14. The wire 19 runs along the elongate tube 12 . When the slide 13 is moved to the end of handle 11 closer to the tube 12 the spring wire 21 of the electrode 14 will be caused to protrude a distance beyond the end of the tube 12. when the slide is retracted to the other end of the handle 11 the spring wire 21 will be drawn at least almost completely within the tube 12. When the electrode 14 projects beyond the end of the tube 12 the spring wire 21 is formed to take on the configuration of an open loop. Retraction of the spring wire 21 into the tube 12 contracts the loop.

The snare 10 forms one electrode in an electro-surgical system (not shown). The other electrode is attached to the patient^'s body at a point distant to the site of the surgical procedure. Each of the electrodes is electrically connected to an RF frequency generator also forming part of the electro-surgical system. In the case of the snare 10 this electrical connection includes a lead 24 which is electrically connected to a terminal 25 on the slide 13 which is in turn electrically connected to the electrode 14. The slot 17 in the handle facilitates the connection of the electrode 14 to the terminal 23.

In carrying out the tonsillectomy procedure according to the present invention the usual operative procedures are followed to the stage of making an incision through the mucosa starting at the at the upper pole of the tonsil and carried anteriorly and posteriorly just within the respective tonsil pillars. This situation is depicted in Fig.3. The tonsil is then grasped by forceps and everted from its bed by traction on the forceps. The traction causes gaping of the anterior mucosal incision. Through this incision a dissecting instrument is inserted and used to separate the capsule from its bed. Usually the anterior pillar is separated first and then the upper pole. The posterior pillar is visualised by everting the upper pole, and under direct vision it is dissected free from the tonsil. This situation is depicted in fig. 4. The finger may also be used as a dissecting instrument in this procedure. In carrying out this dissection the surgeon should as far as possible avoid cutting any of the various blood vessels supplying the tonsil. Once the dissection has progressed to the point where the tonsil is substantially free of the underlying tissue apart from the inferior pole and the various blood vessels the loop of wire 21 of the snare 10 is placed over the tonsil and drawn firm about the anterior pole and the blood vessels. This situation is shown in fig.5. A coagulation current is then caused to flow from the electrode 14 to the patient. A maximum power of about 30 W is probably sufficient to bring about the simultaneous cutting of the tissue ensnared by the loop and to cauterise the blood vessels. Simple trial and experiment with any particular electro-surgical device will indicate the best power setting for any given patient. The tonsil is removed in the usual way after completion of the electro-surgical procedure. Any continuing bleeding can be staunched in the usual manner.

Using the procedure according to the present invention it is possible for the surgeon to use the same snare 10 to remove the patients other tonsil. By comparison conventional, non-electro-surgical snares cannot be used on both tonsils, rather a separate snare must be used for each tonsil due to the frequency of snare breakage in use or due to its deformation in the first use. In replacing the snare the operator is risking injury and infection during the replacement of such a snare as they are conventionally stiff and sharp. The preferred embodiment of the invention utilises a monopolar electrode snare. It would be possible to use a similar snare adapted to operate as a bipolar snare. This could be done by dividing the tube 12 longitudinally into two channels and running a separate wire 19 down each channel. Each of these wires would be connected at its proximal end to a respective one of the poles on the RF signal generator. At their other ends the wires 19 would each be connected to one half of the wire loop 21. The wire loop 21 would itself be divided by an insulator at its apex. In this arrangement the coagulation and cutting current would pass between the two parts of the wire 21 through the intervening tissue. Haemorrhoidectomy according to the present invention is carried out in a manner essentially similar to the tonsillectomy described above. The patient with second- or third-degree haemorrhoids will be treated in the lithotomy position. The sphincter will be widely stretched and the internal haemorrhoids prolapsed by traction on the skin tags, or on skin of the anal margin. Each haemorrhoid will be treated by being picked up with dissecting forceps and traction is exerted. When the haemorrhoid is free of the underlying tissue the forceps will be removed and the loop of an electro- surgical snare slid over the haemorrhoid and it will be then grasped again with the forceps. The loop of the snare will be slid up as close as possible to the base of the haemorrhoid and the loop tightened around the haemorrhoid. The RF generator of the electro-surgical device will then be activated and the loop slowly tightened further. The haemorrhoid will be severed from the underlying tissue and the blood vessels therein will be simultaneously cauterised by the action of the tightening loop through which a cauterising current is being applied to the patient. The severed haemorrhoid may then be removed with the forceps.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are. therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS :

1. A method for removing a highly vascularised tissue body from surrounding tissue wherein the highly vascularised tissue body is attached to the surrounding tissue by connecting tissue and blood vessels and including the steps of loosening the highly vascularised tissue body from the surrounding tissue, and electro-surgically severing the connecting tissue whilst simultaneously at least partly cauterising the severed blood vessels.

2. The method according to claim 1 wherein the highly vascularised tissue body is a palatine tonsil or a haemorrhoid.

3. The method according to claim 1 or claim 2 wherein the highly vascularised body of tissue is electro-surgically removed by way of at least one electrode brought into intimate contact with the connecting tissue.

4. The method of claim 3 wherein the electrode is a snaring means and the highly vascularised body of tissue is removed by tightening the snare around the connecting tissue and applying a current to the electrode.

5. The method according to claim 4 wherein the snaring means acts as an active electrode in a monopolar electro-surgical system.

6. The method according to claim 4 wherein the snaring means acts as both electrodes in a bipolar electro-surgical system.

7. The method according to any one of claims 4 to 6 wherein the maximum power of the current applied is 30W.

8. A device for removing a highly vascularised tissue from the surrounding tissue wherein the highly vascularised tissue body is attached to the surrounding tissue by connecting tissue and blood vessels, including a body, an electrode or electrodes on the body adapted to be brought in engagement with the highly vascularised tissue body, and electro-surgical current generating means operatively connected to the electrode or electrodes, the device being such that the connecting tissue is severed whilst simultaneously the severed blood vessels are at least partly cauterised.