Snare polypectomy by sigmoid-rectal intussusception.

Snare polypectomy by sigmoid-rectal intussusception Appreciable bleeding or perforation after colonoscopic polypectomy is relatively unusual. Nevertheless, either may occur with broad-based sessile polyps owing to insufficient electrocoagulation of the base resulting from excessive current application, excessive snare-wire tightening, or a combination of both. If a polyp base is over about 2 cm in diameter the endoscopist has either to remove it "piecemeal" in several sessions or refer the patient for abdominal surgery. Sigmoid colon polyps have been excised after deliberate intussuscep-tion to the anus using a conventional sigmoidoscope and surgical forceps.1 On two occasions recently we have successfully used this approach at colonoscopy to remove polyps which would have been dangerous or impossible to remove endoscopically. Case reports Case 1-A 63-year-old man was admitted for colonoscopic snare removal of a sigmoid colon polyp diagnosed radiologically. He gave an eight-year history of recurrent colicky lower abdominal pain. On five occasions he had noticed a "lump" which had prolapsed to the anus but could be reduced by lying supine. Colonoscopy was performed with an Olympus CFMB-3 colonoscope. A 2 5-cm, broad-based polyp in the proximal sigmoid colon was snared and polypectomy attempted. The patient began to have pain from Diagram of broad-based mid-sigmoid colon polyp before and after snare loop intussusception. peritoneal irritation before visible electrocoagulation occurred. It was judged dangerous to continue and that the shape of the polyp was unsuitable for complete piecemeal removal. It was resnared with a handleless snare wire.2 This was left in situ tightened on to the base of the polyp, and the colonoscope was withdrawn. The next day under general anaesthesia the polyp was intussuscepted to the anus by 6entle traction on the snare wire and locally excised. The wvound was sutured with absorbable sutures. The polyp histologically was a benign tubular adenoma and was completely excised. The patient was discharged two days later. Case 2-A 65-year-old man was admitted for colonoscopic removal of threc polyps shown radiologically. Snare polypectomy of two 1-cm poiyps in the mid-transverse colon was uneventful. The third polyp in the mid-sigmoid colon was broad based and 2 5 cm in diameter. Snare polypectomy was judged to be difficult and hazardous because of the configuration of the polyp base. The handleless snare loop was closed loosely at the base, the colonoscope withdrawn, and an artery forceps used to hold the loop closed. In the operating theatre and under general anaesthesia the …