Method of and device for cryogenic surgery

[57] ABSTRACT

A system for performing cryogenic surgery, especially the removal or treatment of mammalian tissue such as tonsil tissue, wherein the tissue is drawn by suction into the cavity of an instrument the walls of which are chilled, e.g., by liquid nitrogen.

Claims, 3 Drawing Figures

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PATENTEOJUL 41972

3,674,031

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FIG. 5

H^ns-Joachim Weiche INVENTOR.

BY

Λ^τΙ ^{J J} Attorney

3,674,031

METHOD OF AND DEVICE FOR CRYOGENIC SURGERY

FIELD OF THE INVENTION

My present invention relates to a method of and a device for cryogenic surgery and, more particularly to a system for treating or removing cellular tissue and especially mammalian tissue such as torisil growth.

BACKGROUND OF THE INVENTION

It has been proposed heretofore to provide cryogenic devices for a rapidly expanding branch of surgery referred to as “cryosurgery” or low-temperature surgery. For this purpose, a low-temperature fluid, e.g., liquid nitrogen, is fed through a probe or like structure which is applied to the tissue to be treated or removed, thereby abstracting heat rapidly from this tissue and destroying the tissue structure so that the cells can be taken from the body of the tissue so treated or growth or the like can be separated from the body of the tissue.

Such systems have, however, encountered difficulty in that the cold transmitted to the tissue tends to spread divergently from the site of contact of the probe with the surface of the tissue and often adversely affects healthy tissue or cell growth which is not to be removed or treated and which in many cases : may be vital.

Also, even when removal of the tissue to which the cold is transmitted is desired, the total freezing of the cell tissue in regions somewhat removed from the contact site is not complete, thereby rendering the surgery relatively difficult and often imprecise. It has been difficult, therefore, to concentrate the cold at the tissue site with precision and yet without such dissipation of the low temperature as to enable clean removal of the cellular tissue.

It has been proposed to make use of such cryogenic probes in tonsillectomies which heretofore have required local anesthetic and enucleation or extirpation of the cellular tissue with prolonged convalescence and bed rest. Furthermore, the conventional operation was bloody and could not be carried out effectively with patients in whom loss of blood might lead to other complications. The use of the cryogenic probe eliminated these difficulties by permitting removal of the tonsil follicles without bleeding and while the patient remains ambulatory. The tonsils may be wholly or partly removed upon necrosis resulting from contact with the cryogenic probe.

The use of such probes in tonsillectomies has, however, the disadvantage that immediately behind the tonsils lies the venal and arterial (vascular) system removing blood from and feeding it to the head. Excessive travel of cold from the probe to these sensitive organs has been found to deteriorate the blood vessels and possible damage not only to the surrounding tissue but also to the tissues in the region of the tonsils which must remain intact. As a matter of fact, the damage to such blood vessels increases the time required for healing the region of the tonsillectomy. Consequently, cryogenic: probes have not been found to be satisfactory to many surgeons. In fact they have not received wide spread acceptance in the ear, nose and throat field and, while they offer many advantages over conventional tonsillectomy techniques, their handling is difficult, complex and frequently gives rise to complications.

OBJECTS OF THE IN VENTION

It is, therefore, the principal object of the present invention to provide an improved instrument for cryogenic surgery 65 ^an&lt;^ constituting a shell, the outer rim of which is bent outwherein the aforementioned disadvantages can be avoided.

Another object of this invention is to provide an improved apparatus or device for the removal of cellular tissue, especially mammalian tissue, without excessive damage to surrounding tissue and without complications which have hereto- 70 form the handle or part thereof and is connected to a suction fore been encountered in cryogenic surgery using cold probes and the like.

Still another object of my invention is to provide an improved method of removing selected portions of cellular tissue __ __ __ from the human anatomy and especially tonsils or parts 75 may be of the type commonly'employed in“sur^calinstril· thereof with minimum damage to the vascular system adjoining such tissues.

It is a further object of my invention to provide a device readily and accurately manipulatable by surgeons or other workers in the field with minimum danger of complications and maximum effectiveness for the removal of tonsils and like cellular tissue.

SUMMARY OF THE INVENTION

I

These objects and others which will become apparent hereinafter are obtained, in accordance with the present invention, by the provision of a concave shell at the end of the cryogenic instrument which may be placed over the area to be subjected to cryogenic surgery and communicating with a suction source while being provided with means for cooling the wall of this cell externally of the concavity.

The present system thus includes a suction device for drawing the cellular tissue into the concavity concurrently with the cryogenic freezing of this tissue by heat transfer through the wall of the cavity of a cryogenic fluid in contact with this wall. The cooling system may include means for circulating a coolant through the instrument or merely designed to deliver a coolant to the surface whereupon the coolant may be discharged.

The suction action in accordance with the present invention makes use of a cavity which is preferably dimensioned to the volume of the cellular tissue to be affected by cryogenic surgery, i.e., the volume of the tissue to be removed. It has been found, most surprisingly, that by drawing the removable tissue out of its normal position, e.g., by distorting the tissue into the concavity, it is possible to transfer cold to this limited volume of tissue more or less preferably and without any significant dissipation of the cold or travel thereof to adjacent areas which remain unaffected by the cryogenic action. The significant advantage of the system of the present invention over conventional systems making use of cold probes, therefore, resides in the convergence of the cold upon the cellular tissue drawn into the concavity and the exclusion of adjacent tissue from cryogenic attack. When the system is applied to tonsillectomies, therefore, the cryogenic attack and removal is limited to the tonsil follicles without any danger of adversely affecting the vascular system communicating blood to and from the head.

It is contemplated, in accordance with the present invention, to provide concavities of the character described in the form of heads at the ends of an elongated handling facilitating manipulation of the instrument, the concavity being dimen50 sioned and shaped to correspond to the tissue to be removed.

It will be understood, of course, that a wide variety of sizes and shapes of the concavity, in terms of depth and breadth can be provided at relatively low cost in the form of a set of such instruments so that the practitioner need merely select the instrument of closest proximity to the volume and configuration of the tissue removal desired. The dimensioning of the instrument, need not, however, be precise since the suction action will invariably concentrate or localize the cryogenic action at 60 the tissue drawn into the concavity and repeated operations may be carried out with, say, a smaller concavity than might otherwise be desirable.

The instrument according to the invention is advantageously provided with a hollow body open at one end wardly at a radius or is of rounded configuration to minimize any tearing of the tissue during the induced movement of the tissue into the concavity. Communicating with the concavity at a location close to the apex thereof, is a tube which may source. The convex outer surface of this shell-like element receives the cooling fluid, e.g., liquid nitrogen. The shell itself is preferably composed of a material having a high coefficient of heat transfer, advantageously a metal which is inert and

3,674,031 merits: silver, stainless steel or the like. It has been found to be advantageous, moreover, to provide the concavity with a ratio of depth-to-mouth diameter between 1:10 and 1:1 and to provide a wall thickness which is of the order of millimeter and is in a ratio to the depth of the cavity between 1:2 and 1:10.

Most desirable, the hollow shell is of double-wall construction, i.e., is formed with a compartment extending along the outer wall of the concavity and constituting a cooling compartment and a handle may be provided in the form of a coaxial-tube arrangement one tube of which serves to deliver the coolant while the other carries it away from this chamber. Preferably the inner tube, which may be of relatively small diameter, supplies cryogenic liquid which expands into the chamber and passes through the outer tube as a vapor or gas. It is interesting to note that all of the embodiments described are characterized by a rapid transfer of cold (or abstraction of heat from) at the cellular tissue to be treated and indeed a significantly more rapid transfer than conventional cold probes even though the wall thickness of the probe and the instrument according to the present invention are similar. ²⁰

The present invention, while finding its most significant application in cryogenic surgery and in the treatment of human cellular tissue is also suitable for use in biology and veterinary medicine in general. In fact, wherever more or less flexible materials are to be cryogenically treated, the instrument of the ^zpresent invention finds application.

DESCRIPTION OF THE DRAWING

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being , made to the accompanying drawing in which:

FIG. 1 is an axial cross-sectional view schematically illustrating the principles of the present invention;

FIG. 2 is a sectional view similar to FIG. 1 showing the instrument in operation; and

FIG. 3 is a further sectional view of a preferred embodiment of the invention.

SPECIFIC DESCRIPTION

In FIGS. 1 and 2,1 have shown a device for performing tonsillectomies but which is suitable for other cryogenic operations and substantially any treatment of relatively soft matter with cold.

The device comprises a thin-walled metal cup 1 having a shell configuration and formed with a concavity la which is open against the tissue portion 2 to be treated with cold. As is apparent from FIGS. 1 and 2, the depth d of the concavity can be a fraction of the mouth diameter D or may equal or exceed this diameter as shown in FIG. 3 and as described above. The mouth lb of the shell 1 is formed with an outwardly turned and rounded rim 1c which defines a radius portion id at the annulus with which the instrument contacts the tissue 2. The radius id prevents tearing of the tissue when the latter is drawn by suction into the concavity la. At a portion of the shell distal from the surface 2α of the tissue body, I provided an orifice le which communicates between the concavity la and a tube 3 formed unitarily with the wall 2 and serving to apply suction to the concavity, e.g., via a suction pump or aspirator 3α.

In FIG. 2,1 have shown the instrument of FIG. 1 in operation. Suction applied to the bore 3b of tube 3 reduces the pressure within the concavity la, thereby drawing the tissue body 2b surrounded within the annulus lb into the concavity and into contact with the inner surface thereof. A cryogenic cooling medium, e.g., nitrogen, passes the outer surface lb of the shell 1 as represented at 4, thereby cooling the shell which lies in heat conductive relationship to the bulge 2b of tissue received within the concavity. The cold transfer is represented diagrammatically by the arrows in FIG. 2 and appears to con verge to a center close to the center of curvature of the inner wall of the concavity. As a result, freezing and cell destruction occurs along an arc defined by the arrowheads without spread of the damage to areas beyond the outline ib. When the tissue has been sufficiently cooled, with continued suction, the in5 strument is drawn away from the tissue body and carries with it the tissue to be removed.

In FIG. 3,1 have shown an embodiment of this invention wherein the cooling medium may be recirculated. In this case, the shell 8 is substantially hemispherical and is formed as a 10 double wall or socket body, the outer wall of which is represented at 7. The walls are formed unitarily with one another and adjoin at the rounded rim 8α defining an annulus contacting the tissue surface 2. The inner chamber 9 of the hollow-wall body 5 is a cooling compartment to which the coolant supplies via a passage 10α in an inner duct leading from a refrigerating system or liquid nitrogen tank 106 to the interior of the compartment 9. The tube 10 is coaxially surrounded by a tube 11, also unitary with a hollow body 5, and defining a passage 11α of greater cross section than the passage 10α. Consequently a liquid coolant (generally liquid nitrogen) passes through the narrow bore 10α and expands in the chamber 9 with the formed gases emerging via the passage 11α for recycling or release. The coaxial tubes 10 and 11 or the tube 6 may constitute a handle or may be mounted in a handle to facilitate manipulation of the device by the surgeon. The tube 6, whose bore 6a opens into an orifice 6b at the apex of the concavity 8b, is connected to a suction pump 6c as described with reference to the embodiment of FIGS. 1 and 2. The device of FIG. 3, of course, operates identically to the device of FIGS. 1 and 2.