Patent ID: 7137978

Claim:
A cryosurgical instrument and an accessory system, suitable for operating said cryosurgical instrument, said cryosurgical instrument comprising: a distal cryotip, made from material with high thermal conductivity the internal surface of which is covered with a metal porous coating having open porosity; an elongated tubular sub-unit comprising an external shaft made from flexible or rigid material the distal end of which is sealed by a surface of said cryotip; a central feeding-venting tube situated therein and adapted for delivering a cryogenic liquid therethrough to an internal surface of said distal cryotip and for removing vapors generated in the process of boiling of said cryogenic liquid on the internal surface of said distal cryotip; a coaxial tubular piece positioned in the gap between the distal sections of said central feeding-venting tube and said external shaft; and an inlet-outlet connection provided at the proximal end of said central feeding-venting tube; wherein the distal end of said coaxial tubular piece is sealed by said external shaft or by said cryotip, and the proximal end of said coaxial tubular piece is sealed by said central feeding-venting tube, said accessory system comprises: a thermo-insulated tank for supplying said cryogenic liquid; a feed pipe, the lower end of which is positioned near the bottom of said thermo-insulated tank; a multi-way valve comprising: a first inlet connected to an outlet connection of said feed pipe via a first duct, a second inlet connection communicated by a second duct with a bottle used to provide a pressurized gas, an outlet connection communicated via a third duct with the atmosphere or with a vacuum pump, and an inlet-outlet connection communicated with said inlet-outlet connection of said central feeding-venting tube of said cryosurgical instrument via a main duct; an electromechanical or pneumatic drive for sequentially changing communication state between said inlet-outlet connection and said first, second and third ducts; a sensor used for controlling a changeover frequency of said multi-way valve; a set of four shut-off valves installed on said main, first, second and third ducts; and a control unit, for controlling said changeover frequency and said shut-off valves.