Use of pressure release valve to prevent colonic injury during colonoscopy.

Although bowel perforation during colonoscopy is often related to direct endoscopic pressure or injury in the rectosigmoid area, colonic perforation has been also reported with overinflation of air. This latter type of rupture appears related to formation of a blind loop, to an overly competent ileocecal valve that prohibits colonic decompression, or to use of particular power sources that generate unsafe pressure levels. In an effort to obviate this pneumatic type of rupture, the authors tested a pressure release valve developed by the Olympus Corporation that supplants the standard air-water valve in available Olympus colonoscopes. Use of this valve revealed a significant difference in mean and maximal intracolonic pressures generated during colonoscopy. Moreover, its use resulted in a marked decrease in tissue damage in the pneumatically inflated cadaver colon. Incorporation of such a pressure release valve into available colonoscopes should reduce the risk of pneumatic colon rupture and improve the safety of diagnostic colonoscopy.