Experimental evaluation of water-jet dissection in endoscopic surgery.

The problems associated with high-velocity high-pressure water-jet dissection were investigated by in-vivo experiments using endoscopic equipment. Three problems were identified: backspray with fouling of the optic, poor control of the depth of cut, and detachment of tissue fragments and isolated cells which contaminate the operative field. The first two problems have been resolved by adoption of a hooded hand-piece and the incorporation of an adjustable back stop. A "dry" system which enables the evacuation of the back spray may deal with the problem of contamination of the operative field by detached cells but further in-vivo experiments are needed to confirm this. Until then, water-jet cutting is considered unsafe for both open and endoscopic surgery in patients undergoing extirpative procedures for cancer because of the risk of tumour seeding within the peritoneal cavity.