GB1427415A - Cryosurgical instruments - Google Patents

Abstract

1427415 Cryosurgical instruments T A ARMAO 21 Sept 1973 44507/73 Heading A5R A method of preventing cryoadhesion of cryosurgical instruments to body tissue comprises placing on the surface of the instrument which comes into contact with tissue, a coating of anti-adhesion material which is a good conductor of heat, is liquid at cryogenic temperatures and is non-toxic to body tissue. The antiadhesion material is a viscous fluorocarbon. A cryosurgical instrument has a hollow member 12 of good heat conducting material having an inlet passage 13 and an outlet passage 14 for cryogenic fluid, and a sheath 15 of good heat conducting material spaced from members 12 to define therewith an enclosed space 16 into which opens a passage 18 for anti-adhesion liquid, at least a portion of the sheath being porous so that the liquid can flow out to the tissue-contacting surface. A blade 17 with cutting edge 17a may be secured in the sheath. A porous metal structure the pores of which are interconnected may be located in space 16. The sheath may comprise an apertured inner layer and an outer layer of porous metal. The sheath may be of porous stainless steel or a material woven from stainless steel wire and may be detachable from member 12. The blade may comprise two halves the inner surfaces of which are shaped to provide a V- shaped groove through which the anti-adhesion liquid flows to exit between their edges which are at the cutting edge of the blade. In a modification the blade comprises alternate sheets of porous stainless metal and non-porous stainless metal. In a further modification the blade comprises a central core with a cutting edge and outer porous members. The blade may also comprise a plurality of non-porous metal sheets each having a side with depressions therein located against a smooth side of an adjacent sheet to provide liquid passages. The instrument may also comprise a probe having cryogenic fluid passages 33, 34 connecting with a hollow member 31 and a porous metal sheath 35 supplied with anti-adhesion liquid through passage 39. The sheath may have a covering of steel wool-like material or may be provided with a non-porous portion 35e at its tip and an annular covering 35f of steel wool-like material. The instrument may also comprise a hollow surgical element, e.g. a scalpel, having inlet and outlet passages for cryogenic fluid and spray means directed along the outside of the element and connecting with a supply passage for anti-adhesion liquid so that the liquid can be continuously sprayed along the element. A system for supplying cryogenic fluid and anti-adhesion liquid is also disclosed.