Abstract
With the recent development of endoscopic devices with increased instrumental efficiency, the application of endoscopy is no longer limited only to the field of diagnosis but has been extended to facilitate treatment of lesions inorgans or body cavities under direct vision. Meanwhile, the usefulness of cryosurgery has recently been widely propagated. However, this technique of surgery has at present rather limited clinical applications to the body surface and region close to it. We have devised two different procedures for the practice of cryosurgery within the gastrointestinal tract under direct vision via an endoscope. Procedure 1 Endoscopic cryo-contact method: The probe used in this technique consists of a pliable tube (9mm diam. x 900 mm length) with a foremost metal cooling device (9 mm diam. x 30 mm length) where the extreme cold is produced via adiabatic expansion of nitrous oxide gas cirulating in it. The metal cooling device with the same angular mechanism as fiberscope is passed into the digestive tract along with a GIF-P fiberscope and applied with pressure onto a lesion under direct f iberscopic vision. Procedure 2 Endoscopic cryo-spray method: An instrument consisting of a pressure-aspirtion interlocking device, a spray-nozzle and a baroceptive system, with the use of liquid nitrogen which is sprayed directly over a lesion through biopsy or manipulatory fiberscope. This presentation deals with the basic experimental findings and the results of clinical tests of these cryosurgical procedures.
