Subsequent Adenomas of Ileal Pouch and Anorectal Segment after Prophylactic Surgery for Familial Adenomatous Polyposis.

Abstract

Familial adenomatous polyposis (FAP) is an autosomally dominant disease characterized by the early development of colorectal adenomas and carcinoma in untreated patients. Patients with FAP may develop rectal cancer at their initial presentation (primary) or after prophylactic surgery (secondary). Controversies exist regarding which surgical procedure represents the best first-line treatment. The options for FAP are ileorectal anastomosis (IRA) or a restorative proctocolectomy (RPC) with either a handsewn or a stapled ileal pouch-anal anastomosis (IPAA), with or without mucosectomy. The purpose of these surgeries is to stop progression to an adenoma-cancer sequence by eradicating the colon, a disease prone organ. Unfortunately, these surgical procedures, which excise the entire colon and rectum while maintaining transanal fecal continence, do not guarantee that patients still won't develop adenomas. Based on the available literature, we therefore reviewed reported incidences of pouch-related adenomas that occurred post prophylactic surgery for FAP. The review consists of a collection of case, descriptive, prospective and retrospective reports.

Objectives: To provide available data on the natural history of subsequent adenomas after prophylactic surgery (by type) for FAP.

Methods: A review was conducted of existing case, descriptive, prospective and retrospective reports for patients undergoing prophylactic surgery for FAP (1975 - August, 2013). In each case, the adenomas were clearly diagnosed in one of the following: the ileal pouch mucosa (above the ileorectal anastomosis), within the anorectal segment (ARS) below the ileorectal anastomosis, or in the afferent ileal loop.

Results: A total of 515 (36%) patients with pouch-related adenomas have been reported. Two hundred and eleven (211) patients had adenomas in the ileal pouch mucosa, 295 had them in the ARS and in 9 were in the afferent ileal loop. Patients with pouch adenomas without dysplasia or cancer were either endoscopically polypectomized or were treated with a coagulation modality using either a Nd:Yag laser or argon plasma coagulation (as indicated). Patients with dysplastic pouch adenomas or pouch adenomas with cancer had their pouch excised (pouchectomy).

Conclusion: In patients with FAP treated with IRA or RPC with IPAA, the formation of adenomas in the pouch-body mucosa or ARS/anastomosis and in the afferent ileal loop is apparent. Because of risks for adenoma recurrence, a life time endoscopic pouch-surveillance is warranted.