Ileal Pouch Adenomas and Carcinomas After Restorative Proctocolectomy for Familial Adenomatous Polyposis

Abstract

Restorative proctocolectomy and IPAA has become the treatment of choice in familial adenomatous polyposis. However, several cases of adenomas and carcinomas arising in the ileal pouch were reported. The aim of this study was to evaluate the prevalence and natural history of ileal pouch adenomas and the development of carcinomas in patients with restorative proctocolectomy for familial adenomatous polyposis. We prospectively studied patients who underwent IPAA during the past 20 years at the surgical unit of the University of Florence in Italy. We investigated the extent of the risk and the factors that are involved in the development of neoplastic changes of the pouch. Furthermore, because it is not entirely clear when and how polyps should be treated, we have revised our modality of treatment for this unusual pathology. Sixty-nine patients with familial adenomatous polyposis underwent restorative proctocolectomy. In 66 patients, handsewn ileoanal anastomosis with anal canal mucosectomy was performed. After surgery, all patients underwent endoscopic surveillance. After 10 years of follow-up, 1 ileal pouch adenoma was found in 64.9% of restorative proctocolectomy patients, and ileal pouch carcinomas occurred in 2 patients (29 and 59 years old), 3 and 11 years after restorative proctocolectomy. The number of colonic adenomatous polyps influenced the occurrence of pouch adenomas. No patients with <200 colonic adenomas experienced pouch adenomas, but 46% of patients with >1000 colonic polyps had pouch adenomas, and 25% of patients with 200 to 1000 colonic polyps had pouch adenomas at follow-up. No relationship was found between ileal pouch adenomas and pouch shape (J, S, or straight ileoanal anastomosis with multiple myotomies) or the APC mutation. Polyps larger than 5 mm were removed by endoscopy or surgery. Ileal pouch adenomas were common after restorative proctocolectomy. Patients >50 years of age and patients with >1000 colonic adenomas at the time of colectomy were more prone to ileal pouch adenomas. The development of malignancy in the terminal ileum can present a fast course and does not seem to follow the classic adenoma-carcinoma sequence.