Cumulative risk of developing polyps or malignancy at the ileal pouch-analanastomosis in patients with familial adenomatous polyposis

Restorative proctocolectomy with an ileal pouch-anal anastomosis is perform ed in an increasing number of patients with familial adenomatous polyposis (FAP). Two techniques are currently used to construct an ileal pouch-anal a nastomosis: (1) a double-stapled anastomosis between the pouch and the anal canal and (2) mucosectomy with a hand-sewn ileoanal anastomosis at the den tate line. Although this procedure is thought to abolish the risk of colore ctal adenoma, an increasing number of case reports have been published conc erning the development of adenoma at the anastomotic site. The purpose of t his study was to evaluate the overall cumulative risk of developing adenoma tous polyps after ileal pouch-anal anastomosis and to compare the cumulativ e risk after either anastomotic technique. A total of 126 consecutive FAP p atients undergoing a restorative proctocolectomy were identified from polyp osis registries in The Netherlands, Denmark, Italy, Germany, and New York. Life-table analysis was used to calculate the cumulative risk of developing polyps in 97 patients with at least 1 year of endoscopic follow-up (median 66 months, range 12 to 188 months). A double-stapled anastomosis was used in 35 patients, whereas in 62 patients a handsewn anastomosis with a mucose ctomy was performed. Ln 13 patients polyps developed at the anastomotic sit e, foul with severe and four with moderate dysplasia. None of the patients developed a carcinoma at the anastomotic site. The cumulative risk of devel oping a polyp at the anastomotic site was 8% (95% confidence interval 2% to 14%) at 3.5 years and 18% (95% confidence interval 8% to 28%) at 7 years, respectively. The risk of developing a polyp at the anastomotic site within 7 years was 31% for patients with a double-stapled vs. 10% for patients wi th a hand-sewn anastomosis with mucosectomy (P = 0.03 [log-rank test]). Bec ause FAP patients undergoing a restorative proctocolectomy with either a do uble-stapled or hand-sewn anastomosis have a substantial risk of developing adenomatous polyps at the anastomotic site, lifelong endoscopic surveillan ce is mandatory in both groups.