A new closed-loop cryosurgical device for endometrial ablation

Abstract

A new cryosurgical device was developed in an attempt to overcome problems of current systems. It incorporates a mixed-fluid J-T stage, thereby reducing working pressure. This allows incorporation of an oil-free compressor to circulate the mixture and eliminates the need for coolant replenishment. The compressor console is small and portable, with a footprint of 3.5 square feet. Probe surface temperatures of −90 to −110°C are achieved. Working pressures are reduced 3- to 10-fold over existing devices (300–350 p.s.i.). In a live goat study, liver ice balls 3.7 cm in diameter were created in 10 minutes. In an extirpated uterus, in a 37°C water bath, tissue ice balls ranging from 29.1 to 35.4 mm were created in 6 minutes and tissue was destroyed to depths of 6 to 12 mm. This cryosurgical system is suitable for endometrial ablation.