Abstract: The invention concerns a cryosurgical instrument with a probe for cooling limited zones of biological tissues, of which the thermally well-conducting tip has a hollow interior cross-section, into which a supply conduit connects with a constricted exit gap, through which a gas for cooling of the tip by means of the Joule-Thomson effect can be supplied by flow through the exit gap and can be led away therefrom through a coaxial discharge conduit open eventually to the atmosphere, the instrument also being provided with a device for control of the temperature of the probe tip.

Abstract: A heating coil close to the freezing tip of a cryosurgical probe operates through a highly heat conductive portion of the probe wall so as to cauterize previously frozen tissues. The liquid nitrogen supply is continued long enough to cool the cauterizing surface to body temperature after the heating winding is switched off, after which the probe is withdrawn. An insulating spacer member on the end of the tip prevents unintended freezing of the bladder wall when the instrument is used for an operation on the prostate gland. The use of general anesthesis in such an operation is avoided by the use of the new probe. A probe for cauterizing only, for use after freezing by a conventional cryosurgical probe has the same kind of heater, temperature sensor and insulating tip but is equipped for circulating cooling water rather than cryogenic flow in the cooling space.

Abstract: The base of a clip or forceps for application of high-frequency electricity for coagulation of living tissues provides mechanical securing of the electrodes to each other by means of a dovetail tongue and groove engagement with an intervening insulation layer of material hardened after injection between the jaws or branches of the clip. A contact socket can simply be applied over the surface of the base of the clip, so that the device is easily handled by the surgeon, while at the same time the security of the mechanical fastening at the base of the clip is not subject to impairment by repeated sterilization at 134.degree. C.

Abstract: To insulate the supply lines to an operating tip of a cryogenic surgical instrument, a coaxial assembly of tubes is provided, the inner one being connected to a supply of cryogenic liquid, such as liquid nitrogen; the space between the outer wall of the inner tube and the next tube forming a return line for evaporated cryogenic liquid which is vented to the atmosphere; and the space between the outermost one of the coaxial tubes and the intermediate tube containing a gas such as normal butane, introduced at atmospheric pressure and which has high heat-insulating properties, and which solidifies, or sublimates, to avoid a vacuum and make possible construction of the supply lines as plastic, preferably polyamide tubes, retaining flexibility in use.