Objective: The study compared the risk of adenoma or carcinoma formation in the anorectal segment after either mucosectomy with manual anastomosis or stapled ileoanal anastomosis (IAA) following restorative proctocolectomy (RPC) for familial adenomatous polyposis (FAP).
Background: Few data exist on the risk of adenoma formation after either technique in FAP.
Methods: All endoscopy and histology reports for patients having RPC for FAP attending for annual pouchoscopy from 1978 to 2007 were reviewed. The incidence, timing, and histological characteristics of adenoma or carcinoma formation were recorded.
Results: Of the 206 patients, 140 attended for endoscopic follow-up for a median of 10.3 years after RPC. Fifty-two patients developed neoplastic transformation in the anorectal segment, with a cumulative risk at 10 years of 22.6% after mucosectomy with manual anastomosis and 51.1% after stapled IAA (P < 0.001). The median time to first adenoma was longer after mucosectomy with handsewn anastomosis than after stapled IAA (10.1 vs 6.5 years, P < 0.001). On multivariate analysis, stapled IAA (hazard ratio= 3.45, 95% confidence interval = 1.01–4.98) and age at RPC older than 40 years (hazard ratio = 2.20, 95% confidence interval = 1.01–4.89) were significantly associated with increased risk of adenoma formation. Nine patients developed a large (>10 mm) adenoma. One patient (handsewn ileoanal anastomosis) developed adenocarcinoma in the anorectal mucosa at 13 years and required pouch excision.
Conclusions: Adenoma formation in the anorectal mucosa after RPC for FAP is common but carcinoma is rare. The risk is lower after mucosectomy with handsewn anastomosis than after stapled IAA. Regular endoscopic surveillance after either technique is mandatory.