Adenoma formation and malignancy after restorative proctocolectomy with or without mucosectomy in patients with familial adenomatous polyposis.

Background: There is controversy concerning whether or not to perform mucosectomy after IPAA in patients with familial adenomatous polyposis. Although more frequent adenoma formation at the anastomotic site in patients without a mucosectomy is documented, the interpretation of the theoretical reflections and empirical findings are ambiguous.

Objective: The aim of this study was to assess the differences in adenoma formation at the anastomotic site and in the ileal pouch among patients with familial adenomatous polyposis after IPAA with or without mucosectomy.

Design: Data were gathered from The Norwegian Polyposis Registry and The Cancer Registry of Norway.

Patients: Sixty-one patients with familial adenomatous polyposis who had IPAA were included in the Norwegian Polyposis Registry.

Main Outcome Measures: The frequency of adenoma development in the pouch or at the anastomotic site was measured.

Results: Thirty-nine patients had a pelvic pouch performed with mucosectomy and 22 patients without. The observational time was 15.5 and 13.7 years. Adenoma formation at the anastomotic site was 4 in 39 and 14 in 22, and the estimated rate was 17% vs 75% (p = 0.0001). One patient without mucosectomy had a cancer (Dukes A) at the anastomotic site. There was no estimated long-term difference in adenoma formation in the ileal pouches between the 2 surgical procedures (38%) (p = 0.10).

Limitations: The study is retrospective, in part, and relies on data from registries. There is a limited number of cases, and selection bias because of surgeon preference may exist.

Conclusion: In patients with familial adenomatous polyposis who undergo IPAA, adenoma formation at the anastomotic site is significantly reduced after mucosectomy. Mucosectomy may be the preferable procedure to prevent adenomas at the anastomotic site.