US3393679A - Cryosurgical instrument - Google Patents

Description

July 23, 1968 R. E. CRUMP ETAL 3,393,679

CRYOSURGICAL INSTRUMENT 5 Sheets-Sheet l Filed Dec. 27. 1965 INVENTORS July 23, 1.968 R. E. CRUMP ETAL 3,393,679

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United States Patent O 3,393,679 CRYOSURGICAL INSTRUMENT Ralph E. Crump, Trumbull, and Frank L. Reynolds, Monroe, Conn., assignors to Frigitronics, Inc., Bridgeport, Conn., a corporation of Connecticut Filed Dec. 27, 1965, Ser. No. 516,383 13 Claims. (Cl. 12S-303.1)

ABSTRACT OF THE DISCLOSURE A cryosurgical instrument in the form of a hand-held casing having a tipped member extending therefrom defining a low temperature boiling chamber with a supply tube and an exhaust tube communicating therewith. An inlet valve having a metering oritce therein is located between the supply tube and the boiling chamber and an exhust valve is associated with the exhaust tube. An actuating lever, operatively connected to the normally open inlet valve and normally closed outlet valve, is provided for simultaneously closing the inlet valve and opening the exhaust valve to cool the tip.

One of the most exciting aspects of modern-day surgery has lbeen the development of techniques for performing various surgical procedures by drastic cooling of limited regions of the patients Ibody. These techniques are included within the general subject of cryosurgery and the instruments for performing them are known as cryosurgical instruments. Cryosurgery has already been employed in the treatment of numerous diseases and shows great promise in others. These surgical techniques may make use of any of several characteristics of cryosurgery. One such characteristic is the formation of an ice'ball within the tissues and the adherence of the tissues to a refrigerated probe. This permits manipulation of the affected part with substantially reduced pro'bability of tearing and has 'been highly successful, for example, in cataract removal. A second characteristic of cryosurgery is that cells may `be killed by lowering their temperature below a certain level. This technique has been employed in brain surgery on the thalamus to remove the crippling disabilities of Parkinsons disease. Cell destruction is also employed in the treatment of detached retina. This treatment involves placement of the probe against the back of the eyeball and freezing a small portion of the choroid and retina. Upon healing, a scar is formed which acts as a weld and holds the retina in place.

Various cryosurgical instruments have been developed for utilizing the techniques of cryosurgery. Several methods have been used for cooling the tips or probes of these instruments. These include pre-chilling by an exterior medium such as Dry Ice; thermoelectric refrigeration; internal cooling by passing a low temperature liquid therethrough; and vaporization of a low 'boiling liquid within the instrument tip. External cooling is of very limited practicality. Heat removal capacity and temperature control are dependent upon physical characteristics of the probe and sustained low temperatures cannot be achieved. Thermoelectric cooling has much to recommend it, particularly for use in manipulation. However, for cell destruction, scar formation, or necrosis, there are three thermal parameters that must be controlled: (l) A terminal temperature that insures the goal; (2) The rate at which the heat is withdrawn;

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(3) The change in temperature with respect to timei.e., some tissue can be frozen and returned to its viable state when thawed.

At this point, it would be well to refer to another problem in cryosurgery. This is the problem of rapidly warming or cooling the probe tip when the surgeon desires. If the surgeon should inadvertently touch some portion of the body, other than that to which the low temperature is to be applied, the tip will immediately adhere to such portion. Safety then requires that he Ibe able to rapidly warm the probe tip so as to remove it without causing injury to healthy tissue. Secondly, it may often be necessary to pass through or by healthy tissue to reach the affected site. For example, in performing a retinal attachment, the probe is passed between the eye socket and the eyeball. Once the proper site has 'been reached, the surgeon should then be able to cool the probe tip rapidly to achieve the necessary necrosis. The ability to warm the tip is lacking in some prior art instruments and in others it is provided by a supplemental electrical heater. The heater is energized by a switch which is separate from the refrigerant flow control. The valving for the refrigerant flow presents a problem in itself, inasmuch as such valving is often located remote from the surgeons hand and, in any event, requires rather complex manipulation.

Accordingly, it is a primary object of the present invention to provide an improved cryosurgical instrument. Other objects are to provide such an instrument which may Ibe cooled to sufficiently low temperatures to induce cell necrosis; which may 'be rapidly warmed and rapidly recooled; wherein warming and recooling are initiated by a single control means; and which is of trustworthy and reliable construction.

The manner in which the foregoing o'bjects are achieved will be more apparent from the following description, the appended claims, and the gures of the attached drawings, wherein:

FIG. l is a plan view of a crysurgical retinal instrument in accordance with this invention, partially lbroken away to illustrate its internal construction;

FIG. 2 is a cross section taken substantially along the line 2 2 of FIG. 1;

FIG. 3 is an enlarged cross section showing the internal construction of the probe and tip;

FIG. 4 is a cross section taken substantially along the line 4--4 of FIG. 3;

FIG. 5 is a cross section illustrating the actuating mechanism of the invention, the mechanism being shown in the warm position;

FIG. 6 is a view similar to FIG. 5, showing the mechanism activated to the freeze position;

FIG. 7 is a cross section of the probe tip when the mechanism is in the freeze position;

FIG. 8 is an enlarged section taken substantially along the line 8-8 of FIG. 2;

FIG. 9 is a perspective view illustrating the construction of one portion of the instrument; and

FIG. 10 is a partially schematic illustration of the instrument connected to a supply cabinet.

The objects of the present invention are achieved by means of a -cryosurgical instrument including a hand held casing and a tip member extending from the casing which defines a low temperature boiling chamber. A supply tube and an exhaust tube communicate with the chamber. Means are provided for injecting a tluid into the supply tube and inlet -valve means is provided in the supply tube between the injection means and the chamber. A metering orice is provided between the injection means and the chamber. An exhaust valve is associated with the exhaust tube. Actuating means are provided for simultaneously closing the inlet valve and opening the exhaust valve and, alternatively, simultaneously opening the inlet valve and closing the exhaust valve.

With reference to the drawings, there is illustrated a cryosurgical instrument including a central body member 10 of rectangular cross section having a rounded forward end 12. Body member 10 defines an elongated cylindrical cavity 14 therethrough. The rear end of the body member 10 is provided with a counterbore 16 (FIG. 9) which extends for a short distance into the body member, forming an annular shoulder 18. The diameter of the counterbore is essentially equal to the outer dimensions of the body member 10. The side walls of body member 10 are slotted from the rear to provide a pair of aligned, horizontal, forwardly extending slots 20 which extend through the side walls into the cavity 14. A cylindrical tubular rearward body member 22 is positioned with its forward end secured within counterbore 16 and abutting against shoulder 18. The internal bore 14 of this member is of the same diameter as cavity 14, and thus forms a rearwardly continuing extension thereof.

Slideably positioned within the cavity 14 is a tubular control block 24, provided with horizontally extending opposed actuating pins 26 which extend through the slots 20. Secured within control block 24 is an exhaust tube 28 which extends forwardly and rearwardly of the control block, as shown in FIGS. and 6. Mounted on the lower surface of the rectangular portion of central body member is a camming plate 30 which has its forward edge substantially aligned with pins 26. An exhaust valve housing 32 is mounted on the rear of rearward body member 22 by means of a reduced diameter portion 34 which is inserted Within the end of the member and sweated, brazed, or otherwise secured in place. A resilient metal bellows 36 interconnects the central body member 10 and the valve housing 32. The rearward end ofthe exhaust valve housing 32 is threaded to receive a hollow plug 38 having a forwardly projecting stud 40 with a conical depression in which is permanently seated by soldering or other means a spherical ball 42. The sides of stud 40 are provided with radial ports 44 which communicate with a central axial opening 46 of plug 38. The exhaust tube 28 is provided with an end are 48 adjacent ball 42.

Mounted in the forward end 12 of central body member 10 is an elongated probe support member 50 which defines a passage 52 which is of larger diameter than exhaust tube 28. A resilient metal bellows 54 interconnects the probe support member 50 and the control block 24 and is open to the passage 52 surrounding the exhaust tube 28. That end of the bellows adjoining the control block 24 is closed. The probe support member 50 is ported to provide a fluid inlet 56 which receives the end of a fluid supply line 58. Mounted in the forward end of exhaust tube 28 is a tubular valve stem 60, which extends through the end of probe support member 50, its forward end having an external taper as shown in FIG. 3. Secured to the end of probe support member 50, and surrounding the valve stem 60, is a probe assembly P.

-Probe assembly P includes a stainless steel fluid inlet tube 62 of larger diameter and surrounding the valve stem 60 so as to form a luid passage 52 therebetween of annular cross section. The rearwardmost end of tube 62 carries a collar 64 seated within a recess 66 in probe support 4member 50. A threaded bushing 68, threaded into the end of the probe support member, secures the collar and tube securely in place. The forward end of the fluid inlet tube 62 is angled to form a downwardly depending tip 70 closed at its end by a .heat conductive 4button 72 of silver or other suitable material of high heat conductivity. The L-shaped volume enclosed by the tip and tube end comprises a boiling chamber 74. Mounted within the uid inlet tube 62, adjacent the tapered end lof valve stem 60, is an annular ring 76 which defines a tapered val-ve seat therein. Along one side of the valve seat there is provided a small inlet metering orifice 78. A thermocouple 80 is embedded in :button 72 and the leads 82 extend outward of the tip 70 through a suitable opening 84. The probe P is completed by a small plastic bushing 86 cemented against the bushing `68 to which is secured the open end of la cylindrical plastic probe insulating housing 88. The probe housing 88 is closed at its outer end and includes an opening through which the tip 70 extends.

The operating mechanism of the instrument of this invention is enclosed by a two-part housing including a lbullet shaped forward housing member 90 and a substantially cylindrical rearward housing member 92. The -forward portion of the rearward housing member is apertured to permit an actuating lever 94 to extend therethrough. The rear end of lever 94 is bifurcated to form a pair of spaced arms 96, each of which terminates in a downwardly extending projection 98 which is rotatably mounted on one of the actuating pins 26 against a resilient plastic washer 97 and held in place by a snap ring 99 housed in an annular slot (not shown) in pin 26. The ends of pin 26 are coated with a plastic heat insulation material 101. Each of projections 98 includes a downwardly extending camming step 100 which abuts against the forward edge of camming plate 30.

The rearward end of housing member 92 is closed by a lbase plate 102 which is apertured to receive a vacuum exhaust line 104, a bushing 106 for the thermocouple leads 82 and the uid supply line 58. The vacuum exhaust 104 is connected to the plug 38 by means of a suitable coupling 108. The fluid supply line 58, therimocoup-le leads 82 and vacuum exhaust line 104 are flexible and are connected -by means of suitable connectors to a cabinet C, which is schematically illustrated in FIG. l0. Fluid supply line S8 is connected to a three-Way valve which permits it to 'be connected either to a standard supply 'bottle 112 of a suitable liquefied gas, or to an exhaust 114. The vacuum exhaust line 104 is connected through a vacuum regulating valve 116 to a vacuum pump 118. The thermocouple leads 82 are connected to a temperature indicating meter 120.

A number of iiuids which have low boiling points are usable in the instrument of this invention. Those which appear to be most suitable are the halogenated hydrocarbons which are noneorrosive and stable. Typical of these uids are dichlorodiliuoromethane, with an atmospheric boiling point of 29.9 C., monochlorodiluoromethane, boiliing at 40.9 C., and bromotriiluoromethane, boiling at -57.8 C. In the disclosed apparatus, these boiling points are lowered even further by applying to the system, by means of vacuum pump 118, a vacuum of approximately 22 inches of mercury. For purposes of illustration only, in a retinal instrument the probe housing 88 might have an external diameter as small as .060 inch and the once 78 might have a diameter of bet-Ween .003 inch and .0005 inch.

Operation With the components of the invention in the position illustrated in FIGS. 2, 3, and 5, it will be noted that the pressurized iiuid will flow into liuid inlet 56 from the supply line 58 and lill passage 52 around the exhaust tube 28 and valve stem 60. From passage 52, the fluid will pass freely into bellows 54 and through the valve ring 76, flooding the chamber 74. It will also be noted that the end iiare 48 of exhaust tube 28 is seated against the lball 42, preventing the escape of fluid into the exhaust line. The iiuid pressure within the bellows 54 serves to expand the bellows and retain the control block 24 and exhaust tube 28 in this rearward position. This is the warm condition of the probe, as the tip 70 is filled with the relatively warm liquid fluid.

With the instrument in this warm condition, the surgeon inserts the probe P between the eyeball and the eye socket and guides it into position. He is guided in this by observation through the iris, observing the indentation made by tip 70. Upon reaching the proper position, the surgeon depresses actuating lever 94. The projections 98 of the lever rotate about the pins 26 and, due to the presence of camming plate 30, force the control block 24 and exhaust tube 28 forward, as shown in FIGS. 6 and 7, against the pressure of the fluid in bellows 54. This results in two valving actions. As shown in FIG. 6, the end flare 48 of the exhaust tube is shifted forwardly from ball 42, thereby opening the exhaust tube through the ports 44 to the vacuum exhaust line 104. At the same time, the forward tapered end of the valve stem 60 is forced into the valve ring 76 (FIG. 7) closing off the incoming supply, with the exception of that which passes through the small metering orifice 78. The vacuum rapidly exhausts the liquid fluid from chamber 74 through valve stern 60 and exhaust tube 28. As the pressure within the boiling chamber 74 begins `to drop, the fluid which is passing through the orifice 718 vaporizes and rapidly lowers the temperature of tip 70 and button 72. The cooling rate is quite rapid and the temperature of -a selected area may be lowered from body temperature to a necrotic temperature in five seconds or less. It will be noted that the `relatively warm pressurized fluid filling the passage S2 forms an insulating layer reducing any tendency to freeze at undesired points along inlet tube 62.

To release the tissue, the surgeon merely releases the actuating lever 94. The fluid pressure within bellows 54 immediately returns the control block 24, the exhaust tube 28, and the valve stem 60 to their rearward position, closing the exhaust at ball 42 and retracting the tapered tip of valve stern 60 from v-alve seat ring 76. A copious flow of fluid then passes through this valve seat, flushing it clear of any foreign particles that might have lodged therein and flooding the boiling chamber 74. The tip 70 thereupon returns to the temperature of the liquid in a fraction of the ltime required for cooling.

It is believed that the many -advantages of this invenrrefrigerant, which is slightly above freezing. This occurs tion will now be apparent to those skilled in the art. It is also believed that many variations and modifications may lbe made in the invention without departing from its spirit and scope. For example, the actu-ation of the mechanism described above is effected by means of a lever. However, the same rresults could be achieved by means of a solenoid coil around the central portion of the instrument. Block 24 could then be of iron and the Coil could be energized by an electrical switch-for example, a foot-operated switch. It will also be apparent that the unique valve of this invention may have applications in other fields than cryosurgery. Accordingly, the foregoing description is to be construed as illustraytive only, rather than limiting. This invention is limited only by the scope of the following claims.

What we claim as new and desire to secure by Letters Patent of the United St-ates is:

1. A cryosurgical instrument which comprises: a tip member defining a low temperature boiling chamber; a supply tube communicating with said chamber; an exhaust tube communicating with said chamber; means for injecting a fluid into said supply tube; inlet valve means in said supply tube bet-Ween said injection means and said chamber; means defining a metering orifice located in said inlet valve means; exhaust valve means associated with said exhaust tube; and actuatin-g means operatively connected to said inlet and exhaust valves for substantially simultaneously closing said inlet valve means and opening said exhaust valve means, and, alternatively, substantially simultaneously opening said inlet valve means and closing said exhaust valve means.

2. The'instrument of claim 1 vwherein said exhaust tube is positioned substantially concentrically of said supply tube.

3. The instrument of claim 2 wherein said exhaust tube is positioned internally of and longitudinally movable relative to said supply tube between a first and a second position and wherein said inlet valve means comprises a valve seat within said supply tube engageable by a first end of said exhaust tube when in said first position.

4. The instrument of claim 3 wherein said exhaust valve means comprises flow obstructing means adapted to engage-the second end of said exhaust tube when in said ysecond position.

5. vThe t instrument of claim 4 wherein said actuating means comprises means for selectively moving said exhaust tube into either of said first and second posit-ions.

6.\A cryosu-rgical instrument which comprises: a handheld casing; a probe tip extending from said casing and defining a.low temperature boiling chamber therein; a fluid supply line; an exhaust line; v-alve means for substantially simultaneously stopping fluid flow from said supply line into said chamber and permitting fluid flow from said chamber into said exhaust line; and means defining a metering orifice located in said valve means for limited passage of the fluid when the fluid flow is substantially stopped.

7. The instrument of claim 6 wherein said valve means comprises: la body member; an exhaust tube having a first and a second end longitudinally movable within said body member between a first and la second position; a supply tube extending from said body member yand surrounding the first end of said exhaust tube to define a fluid passage therebetween, said fluid passage communieatin-g between said chamber and said supply line; first valve seat means in said supply tube adjacent the first end of said exhaust tube to cooperate therewith to close said fluid passage when sai-d exhaust tube is in its first position; exhaust valve means communicating with said exhaust line including second valve seat means adjacent the second end of said exhaust tube to cooperate therewith to close said exhaust tube when in its second position; and actuating means for moving said exhaust tube between its first and second positions.

8. The instrument of claim 7 wherein said metering orifice is defined by said first valve seat means and the first end of said exhaust tube.

9. A combination supply and exhaust valve which comprises: a body member defining an elongated bore therein; an exhaust tube having a first and a second end longitudinally movable within said bore between -a first and a second position; a supply tube extending from said body member and surrounding the first end of said exhaust tube to define a fluid passage therebetween; means for supplying a fluid to said fluid passage; first valve seat means in said supply tube adjacent the first end of said exhaust tube to cooperate therewith to form a first valve to substantially close said fluid passage when said exhaust tube is in its first position; means defining a metering orifice located in said first valve; exhaust valve means including second valve seat means adjacent the second end of said exhaust tube to cooperate therewith to close said exhaust tube when in its second position; yand actuating means for moving said exhaust tube between its first and second positions.

10. The valve of claim 9 wherein said exhaust tube includes a control block portion intermediate its ends and slidable in said bore.

11. The valve of claim 10 wherein cylindrical bellows means is positioned with one end secured to said control block portion and the other end secured to said body member, the interior of said bellows means being in fluid communication with said uid passage.

12. The valve of claim 9 wherein said body member defines first and second slots communicating with said bore; said exhaust tube includes first and second arms extending through said slots; and said actuating means comprises a camming lever rotatably mounted on said arms to move said arms longitudinally within said slots.

13. A cryosurgical instrument for Irepairing retinal detachments which comprises: a hand-held casing; an elongated cylindrical probe housing extending from said ycasing; ya uid supply tube extending from said casing within said probe housing, the outermost end of said supply tube forming a laterally projecting tip extending through the side of said probe housing and dening a low temperature boiling chamber therein; la uid supply line connectable to a source of pressurized low boiling point uid;

References Cited UNITED STATES PATENTS 3,272,203 9/1966 Chato 12S-303.1 3,289,424 12/ 1966 Shepherd 62-55 L. W. TRAPP, Primary Examiner.

D. L. BAKER, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,393,679 July 23, 1968 Ralph E. Crump et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column l, line I8, "exhust" should read exhaust Column 5, line 42, beginning with "It is" cancel all to and including "It" in line 45, and insert refrigerant, which is Slightly above freezing. This occurs in a fraction of the time required for cooling.

It is believed that the many advantages of this invention will now be apparent to those skilled in the art. It

Signed and sealed this 9th day of "December 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, I r.

Attesting Officer

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