COLONOSCOPIC PERFORATIONS - ETIOLOGY, DIAGNOSIS, AND MANAGEMENT

Since its introduction into clinical medicine, flexible fiberoptic col onoscopy has had a great impact on diagnosis and management of disease s of the colon and rectum. There are three mechanisms responsible for colonoscopic perforation: specifically, mechanical perforation directl y from the colonoscope or a biopsy forceps, barotrauma from overzealou s air insufflation, and, finally, perforations that occur during thera peutic procedures. Perforation of the colon, which requires surgical i ntervention more frequently than bleeding, occurs in less than 1 perce nt of patients undergoing diagnostic colonoscopy and may be seen in up to 3 percent of patients undergoing therapeutic procedures such as po lyp removal, dilation of strictures, or laser ablative procedures. Man agement of colonic perforation secondary to colonoscopy remains a cont roversial issue in that it can be effectively managed by operative and nonoperative measures. If a perforation does occur, signs and symptom s that the patient will experience will be related to both the size an d site of the perforation, adequacy of the bowel preparation, amount o f peritoneal soilage, underlying colonic pathology (where a thin walle d colon from colitis or ischemia, for example, may result in a larger perforation than a healthy colon), and, finally, overall clinical cond ition of the patient. Radiology often establishes diagnosis. Plain fil ms of the abdomen and an upright chest x-ray may reveal extravasated a ir confined to the bowel wall, free intraperitoneal air, retroperitone al air, subcutaneous emphysema, or even a pneumothorax. A localized pe rforation may demonstrate lack of pneumoperitoneum. Some surgeons reco mmend surgery for all colonoscopic perforations; however, there does a ppear to be a role for conservative management in a select group of pa tients such as those with silent asmptomatic perforations and those wi th localized peritonitis without signs of sepsis that continue to impr ove clinically with conservative management. Finally, conservative man agement works well in those patients with postpolypectomy coagulation syndrome. Surgery is most definitely indicated in the presence of a la rge perforation demonstrated either colonoscopically or radiographical ly and in the setting of generalized peritonitis or ongoing sepsis. Th e presence of concomitant pathology at time of colonoscopic perforatio n such as a large sessile polyp likely to be a carcinoma, unremitting colitis, or perforation proximal to a nearly obstructing distal coloni c lesion may force immediate surgery. Finally, in the patient who dete riorates with conservative management, one should proceed to surgery.