US3333587A

US3333587A - Cryosurgical device

Info

Publication number: US3333587A
Application number: US428724A
Authority: US
Inventors: Robert D Johnston
Original assignee: Union Carbide Corp
Current assignee: Union Carbide Corp
Priority date: 1965-01-28
Filing date: 1965-01-28
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

1, 1957 R. 0. JOHNSTGN 3,3335%? CRYOSURGICAL DEVICE Filed m. 28, 1965 INVENTOR ROBERT D. JOHNSTON 50 ATTORNEY United States Patent O 3,333,587 CRYOSURGICAL DEVICE Robert D. Johnston, Brownsbnrg, Ind., assiguor to Union Carbide Corporation, a corporation of New York Filed Jan. 28, 1965, Ser. No. 428,724 10 Claims. (Cl. 128-3031) This invention relates to cryosurgery devices and particularly to such devices adapted to conduct a refrigerant to a surgical tip member regardless of the attitude of the device.

Known cryosurgery devices comprise a source of refrigerant, a surgical tip member, and means such as a vacuum-insulated hose to transport the refrigerant from the source to the tip member. For some purposes, the elongated refrigerant transfer means is cumbersome and could be a serious handicap. One such purpose is cryosurgery on opthalmic tissues where the surgical tip must be easily manipulatable.

An object of this invention is to provide a compact cryosurgery device which incorporates a refrigerant source and a surgical tip member within one body. Anotherobject is to provide such cryosurgical device adapted to apply low temperatures to opthalmic tissues. A further object is to provide such a cryosurgical device having a double-walled Dewar and probe assembly insulated by a common vacuum.

The cryosurgical device of, this invention comprises a thermally-insulated refrigerant storage container and an elongated thermally-insulated probe connected to the container. The container has a scalable opening providing access to the interior for filling the container with a vaporizable liquid refrigerant. A major portion of the interior of the container is filled with porous material that is adapted to hold a vaporizable liquid refrigerant. The probe extends outwardly from the container and comprises an enclosed thermally conductive tip member attached at the outer end, a refrigerant supply tube extending from the container interior into the tip member, and an enclosed refrigerant exhaust tube extending from the tip member to an exterior outlet provided therefor in a wall of the container. The container is adapted for attachment to a pressurizing device so that liquid stored within the porous material can be pressurized, transferred into the probe to the tip member and then exhausted.

The preferred refrigerant is liquid nitrogen which has a suitably low boiling point and is inert. The pressurizing gas is also preferably nitrogen gas. Other low boiling cryogens may be suitable.

The container preferably comprises a double-walled vessel having an inner vessel, a larger outer jacket gastightly enclosing the inner vessel with an evacuated insulating space between the outer surface of the inner vessel and the inner surface of the outer jacket, and an access tube extending across the insulating space and gas-tightly connected to a wall of the inner vessel and to a wall of the outer jacket in communication with the aforementioned scalable opening. The porous material can be of a porous nature capable of either adsorbing a vaporizable liquid refrigerant such as synthetic crystalline zeolites, or by holding a vaporizable liquid refrigerant by capillary action, such as a monolithic porous mass of sand-lime (calcium silicate) as described in U.S. Patent 2,883,040.

The probe is preferably insulated by an evacuated space enclosed by an elongated, gas-tight shell that encloses the aforementioned refrigerant supply tube and refrigerant exhaust tube, and which extends from the probe tip member to the container outer jacket such that the refrigerative effects of the vaporizable liquid refrigerant are confined to the probe tip member. The probe refrigerant supply tube and refrigerant exhaust tube may be positioned concentrically or longitudinally adjacent within the probe.

The cryosurgical device of this .invention has made possible the clinical development of new cryosurgery techniques for retinal detachment and lens extraction in the human eye by employing the low temperatures of cryogens such as liquid nitrogen. This device has an ultra-low temperature capacity which permits a rapid rate of cooling in excess of 15/sec. A minute warming coil may be incorporated into the probe tip member to provide warming rates in excess of l5/sec. These rapid rates permit precision control in the uniform application of cold. When employed as an opthalmic cryosurgery device, the probe tip employed is curved to p'ermitcorrect angulation and application of the freezing temperature to the desired location on the eye. The entire device is sufliciently compact to enable a surgeon to hold the device in his hand and yet the refrigerant capacity of the device is suflicient for even a protracted surgical procedure. The figure shows a preferred embodiment of the cryosurgical device of this invention. Thermally insulated refrigerant storage container 10 comprises an innervessel 12, a larger outer jacket 14 gas-tightly enclosing the inner vessel with an evacuated insulating space 16 therebetween. An access tube 18 extends across insulating space 16 at one end of container 10 and gas-tightly connectsone end of inner vessel 12 to an adjacent end of outer jacket 14, the latter containing a scalable opening 20 closed by threaded cap 22. Access tube 18 is preferably constructed in the form of bellows, as shown, to provide a longer heat leak path and to allow for any relative expansion or contraction between the inner vessel 12 and the outer jacket 14. For greater protection against heat leakage evacuated space '16 may be filled with an opacified insulation such as described in U.S. Patent 2,967,752 or 3,007,596. A vacuum of less than about 1 micron mercury may be maintained when the inner vessel 12 is cold by a synthetic crystalline zeolite absorbent material, such as described in U.S. Patent 2,900,800, positioned in gas communication with evacuated space 16. In addition, a palladium oxide getter material may be provided in gas communication with evacuated space 16 to remove traces of hydrogen gas. Outer jacket 14 may be provided with a bursting disk and a vacuum pinch-off tube. Inner vessel 12 is substantially completely filled with a calcium silicate porous material 24. Porous material 24 is provided in a plurality of sections, two being shown, 'separated by porous means such as screens 26 which extend transversely across the interior of inner vessel 12. Screens 26 have a relatively coarse mesh on' the order of about 50 mesh. Screens 26 serve the function of providing low pressure drop sections through which the porous material 24 can be uniformly and fully saturated with the vaporizable liquid refrigerant when container'ltl is filled. At the end of inner vessel 12 opposite access tube 18 several screens 30 are superimposed in staggered relation to prevent particles of the porous material 26 from being passed beyond the storage space within inner vessel 12 that is occupied by the porous material 24. Screens 30 are of a relatively fine mesh on the order of 240 mesh.

An elongated space 32 axially aligned with access tube 18 passes through screens 26 and porous material 24 so that a refrigerant filling tube may be inserted through access tube 18 into inner vessel 12 in close proximity to screens 30 for filling and saturating porous material 24 with liquid refrigerant. The cross sectional area of porous material 24 is preferably slightly smaller than the cross sectional area of inner vessel 12 such that an outer annular space 34 is provided between the outer surface of porous material 24 and the inner vessel 12. As liquid refrigerant is transferred into inner vessel 12, it will dis- :perse info elongated space 32 and an annular space 34 and thence into the sections of the porous material 24 primarily through screens 26. After the porous material 24 has been saturated with the liquid refrigerant, the filling tube would be withdrawn and the sealable opening 20 closed by cap 22. The liquid refrigerant will remain suspended within porous material 24 until driven otf by the addition of heat or pressure regardless of the attitude of container 10.

Probe 36 comprises a refrigerant supply tube 38, a

tip member 40, refrigerant exhaust tube 42 and an enclosing elongated shell 44. Supply tube 38 gas-tightly extends th-rough the end of inner vessel 12 opposite the access tube 18 into tip member 40. Exhaust tube 42 is gas-tightly connected to tip member 40 and concentrically encloses the portion of supply tube 38 adjacent the tip member 40. Toward the inner end of supply tube 38, supply tube 38 passes gas-tightly through the wall of exhaust tube 42 and the latter extends non-concentrically and gas-tightly into inner vessel 12, through a space 28 provided therefor in porous material 24, and through evacuated space 16 adjacent to access tube 18 to an exterior outlet 46 provided therefor in outer jacket 14. The probe outer shell 44 is connected gas-tightly to tip member 40, enclosing supply tube 38 and exhaust tube 42, and is extended to the outer jacket 14 of container and gas-tightly connected thereto such that space 48 within the outer shell 44 is in gas communication with evacuated space 16 of container 10.

Tip member 40 is preferably curved as shown when the cryosurgical device of this invention is to be used in performing opthalmology operations so that the pointed projection 50 on tip member 40 can be conveniently positioned against the portion of an eye on which the operation is performed. Other tip configurations of course may be employed depending upon the type of cryosurgery to be performed.

The exhaust tube 42 is preferably coiled within evacuated space 12 surrounding access tube 18 so that any residual refrigerative effects of the exhaust refrigerant may be employed to cool that portion of evacuated space 12.

The cryosurgery device depicted in the figure is provided with a pressurizing tube 52 which is gas-tightly connected to inner vessel 12 and outer jacket 14 to provide a means for pressurizing the interior of the inner vessel 12. Pressurizing tube 52 is preferably coiled concentrically with exhaust tube 42, as shown, such that incoming pressurizing gas through pressurizing tube 52 can be cooled by the residual refrigerative effects of exhaust gas passing out through exhaust tube 42.

The cryosurgical device of this invention is preferably operated in the following manner. The porous material 2 is filled with liquid nitrogen in the manner described in a preceding paragraph. A pressurizing gas is then transferred into inner vessel 12 through pressurizing tube 52 at a temperature above the temperature of the liquid nitrogen within porous material 24. The pressurizing gas withgas to the probe tip member 40 by way of supply tube .38

and then to exhaust from the device by way of exhaust tube 42. If the pressurizing gas is initially at about ambient temperature, the heat exchange arrangement between exhaust tube 42 and pressurizing tube 52 will lower the temperature of the incoming pressurized gas to below about --40 F. The temperature of tip member 40 is monitored by a thermo-couple (not shown) attached to tip member 40 and the temperature of tip member 40 may be controlled by controlling the flow rate of pressurizing gas into the cryosurgery device. A relatively high flow rate of pressurized gas will result in greater evaporation of liquid nitrogen within porous material 24 and hence the gas reaching tip member 40 will be colder.

What is claimed is: a

1. A cryosurgical device which comprises a thermallyinsulated refrigerant storage container having a sealable opening providing access to the interior of the container for filling said container with a vaporizable liquid refrigerant; non-metallic porous material positioned within the interior of said container and adapted to hold a vaporizable liquid refrigerant in the liquid phase; a thermallyinsulated probe connected to said container and extending outwardly therefrom comprising a hollow, thermallyconductive tip member, an enclosed refrigerant supply tube extending from the interior of said container into the tip member, and an enclosed refrigerant exhaust tube extending from said tip member to an exterior outlet provided therefor m a wall of said container; and a pressurizing conduit joined to said container in fluid communication with said non-metallic porous material for introducing pressurized fluid to vaporize said liquid refrigerant for flow to said probe.

2. A cryosurgical device according to claim 1 wherein the probe supply and exhaust tubes extend concentrically into said probe tip member; and wherein said supply tube extends gas-tightly through the wall of said exhaust tube toward said container; and wherein said probe supply and exhaust tubes extend gas-tightly and nonconcentrically into said container.

3. A cryosurgical device according to claim 1 wherein said porous material comprises a monolithic calcium silicate filler.

4. A cryosurgical device according to claim 1 wherein said porous material is capable of holding said vaporizable liquid refrigerant in the liquid phase by capillary action.

5. A cryosurgical device which comprises a refrigerant storage container having an inner vessel, an outer jacket gas-tightly enclosing said inner vessel and spaced therefrom to provide an evacuated space between the inner vessel outer surface and the outer jacket inner surface, a sealable opening in the outer jacket Wall providing access to the inner vessel for filling said inner vessel with a vaporizable liquid refrigerant; a bellows-type access tube within said evacuated space being gas-tightly connected to the walls of said inner vessel and outer jacket and having a first end in fluid communication with said sealable opening; non-metallic porous material positioned within said inner vessel so as to fill a major portion thereof, being in fluid communication with a second end of said access tube and adapted to hold said vaporizable liquid refrigerant in the liquid phase; a thermally-insulated probe gas-tightly connected to said container and extending outwardly therefrom comprising a hollow thermally-conductive tip member, an enclosed refrigerant supply tube having one end in fluid communication with said non-metallic porous material in said inner vessel and another end extending through said evacuated space into said tip member, an enclosed refrigerant exhaust tube positioned to extend from said tip member through said evacuated space; an exterior outlet through said outer jacket wall being joined to an end of said exhaust tube in said evacuated space; and a pressurizing conduit having one end extending through the outer jacket wall and said evacuated space, and the other end extending through the inner vessel wall in fluid communication with said non-metallic porous material for introducing pressurized fluid to vaporize said liquid refrigerant and flow refrigerant vapor to said probe.

6. A cryosurgical device according to claim 5 wherein said porous material comprises a monolithic calcium silicate filler.

7. A cryosurgical device according to claim 5 wherein said probe includes an outer shell enclosing the probe supply and exhaust tubes and gas-tightly joining said tip member and said container outer jacket such that the space between the probe outer shell and the probe supply and exhaust tubesis in gas communication with the container evacuated space.

8. A cryosurgical device according to claim 5 wherein a plurality of screens extend transversely across said inner vessel to divide the porous material therein into axiallyadjacent sections; and wherein the crosssectional area of said porous material is less than the cross-sectional area of the inner vessel interior such that an annular space is provided between the inner surface of said inner vessel and the outer surface of said porous material, said plurality of screens extending into said annular space.

9. A cryosurgical device according to claim 8 wherein said porous material is provided with an elongated space axially of said access tube which extends through said screens and said adjacent sections of porous material.

10. A cryosurgical device according to claim 5 wherein said pressurizing conduit is coiled around said access tube within said evacuated space; and wherein the probe refrigerant exhaust tube extends through said inner vessel tube in heat exchange adjacency with said pressurizing conduit.

References Cited UNITED STATES PATENTS 1,516,437 11/1924 Humpoletz. 1,815,570 7/1931 Jones. 2,883,040 4/1959 Pater et al 2067 OTHER REFERENCES I.A.M.A. Cryogenic Surgery of the Basal Ganglia, 128- 401, pp. 600-604, author I. S. Cooper, September 1962.

RICHARD A. GAUDET, Primary Examiner.

into said evacuated space and is coiled around said access 15 MCNEILL, Assistant Examiner-

Claims

1. A CRYOSURGICAL DEVICE WHICH COMPRISES A THERMALLYINSULATED REFRIGERANT STORAGE CONTAINER HAVING A SEALABLE OPENING PROVIDING ACCESS TO THE INTERIOR OF THE CONTAINER FOR FILLING SAID CONTAINER WITH A VAPORIZABLE LIQUID REFRIGERANT; NON-METALLIC POROUS MATERIAL POSITIONED WITHIN THE INTERIOR OF SAID CONTAINER AND ADAPTED TO HOLD A VAPORIZABLE LIQUID REFRIGERANT IN THE LIQUID PHASE; A THERMALLYINSULATED PROBE CONNECTED TO SAID CONTAINER AND EXTENDING OUTWARDLY THEREFROM COMPRISING A HOLLOW, THERMALLYCONDUCTIVE TIP MEMBER, AN ENCLOSED REFRIGERANT SUPPLY TUBE EXTENDING FROM THE INTERIOR OF SAID CONTAINER INTO THE TIP MEMBER, AND AN ENCLOSED REFRIGERANT EXHAUST TUBE EXTENDING FROM SAID TIP MEMBER TO AN EXTERIOR OUTLET PROVIDED THEREOF IN A WALL OF SAID CONTAINER; AND A PRESSURIZING CONDUIT JOINED TO SAID CONTAINER IN FLUID COMMUNICATION WITH SAID NON-METALLIC POROUS MATERIAL FOR INTRODUCING PRESSURIZED FLUID TO VAPORIZE SAID LIQUID REFRIGERANT FOR FLOW TO SAID PROBE.