The Risk of Adenomas and Carcinomas in the Ileal Pouch and Rectum after Surgical Treatment in Patients with Familial Adenomatous Polyposis

Abstract

Purpose: Our aim was to evaluate the prevalence andnature of ileal pouch and non-pouch adenomas andcarcinoma in patients with familial adenomatouspolyposis （FAP）. Patients and methods: This was aretrospective study of 40 FAP patients with Kock’scontinent ileostomy（Kock）（n=8）, ileorectal anastomosis（IRA）（n=8）, and ileal pouch-anal anastomosis（IPAA）（n=24）. All patients were followed by endoscopy in theileal pouch and non-pouch mucosa. Results: Twenty of 32pouch patients（Kock and IPAA） developed adenomas in the ileal pouch mucosa, and all patients with 8 IRApatients developed adenomas in the rectal mucosa. Theprevalence of ileal adenomas was significantly higher inpouch patients than in IRA patients（P ＜ 0.01）. Threecases of adenocarcinomas were found in the ileal pouchmucosa. The risk of adenoma development in the ilealpouch was 10%, 45%, and 90% at 5, 10, and 20 years offollow-up, respectively after proctocolectomy with Kockand IPAA. The risk of rectal adenoma after colectomywith IRA was 50%, 75%, and 100% at 5, 10, and 20 yearsof follow-up, respectively. Conclusion: Our results showa high frequency of adenomas in the ileal pouch mucosa,with evolution into carcinoma in some patients. Regularendoscopic surveillance of the pouch is recommended.