Air-pressure-induced colon injury during diagnostic colonoscopy

Abstract

During colonoscopy, pressurized air is slowly introduced to distend the bowel lumen. This study describes the effect of colonoscopically introduced air pressure on dog, pig, and human cadaver colon and reports measurement of intraluminal air pressure during routine colonoscopy. Four commonly used endoscopic power sources delivered air at pressures in excess of 300 mmHg. Dog colon could not be ruptured by the maximal air pressure generated. In contrast, serosal tears, pneumatosis, and transmural rupture developed in both pig and human cadaver colon at air pressure Jess than 225 mmHg. In every instance, less air pressure was required to produce damage to the right as compared to the left colon. For example, human cadaver cecum ruptured at a mean intraluminal air pressure of only 81 mmHg, while a pressure of 169 mmHg was required for disruption of the sigmoid. During routine colonoscopy in 34 patients, intraluminal pressures ranged from 9–57 mmHg when the endoscope tip was free in the bowel lumen. Maximum pressures observed were usually recorded at a time when the endoscope tip was impacted against the bowel wall and pressures ranged between 34–138 mmHg. This investigation demonstrates that current standard colonoscopic equipment can deliver air at pressures great enough to damage the colon wall; and although intraluminal pressure usually remains low during colonoscopy, potentially it may exceed a level associated with serosal and mucosal tears.