Risk of Proctectomy After Ileorectal Anastomosis in Familial Adenomatous Polyposis in the Modern Era

Abstract

BACKGROUND: Prophylactic surgery for familial adenomatous polyposis has evolved over several decades. Restorative proctocolectomy with ileal pouch anal anastomosis provides an alternative to total abdominal colectomy with ileorectal anastomosis. We have previously shown the rate of proctectomy and rectal cancer after total abdominal colectomy with ileorectal anastomosis in the “pre-pouch” era was 32% and 13%, respectively. OBJECTIVE: To determine the rate of proctectomy and rectal cancer among familial adenomatous polyposis patients and relative-rectal sparing (< 20 rectal polyps) selected for total abdominal colectomy with ileorectal anastomosis in the modern era. DESIGN: Retrospective cohort study. SETTING: Single tertiary care institution with a hereditary colorectal cancer registry. PATIENTS: Familial adenomatous polyposis patients who underwent total abdominal colectomy with ileorectal anastomosis between 1993 and 2020. MAIN OUTCOME MEASURES: Incidence of proctectomy for any indication and rectal cancer. RESULTS: A total of 197 patients with median age of 24 years (range, 10-67) were included. Median follow-up after total abdominal colectomy with ileorectal anastomosis was 13 years (IQR 6-17). Sixteen patients (8%) underwent proctectomy. Indications included rectal cancer in 6 (3%) (2 Stage I and 4 Stage III); polyps with high grade dysplasia in 4 (2%); progressive polyp burden in 3 (1.5%), defecatory dysfunction in 2 (1%); and anastomotic leak in 1 (0.5%). Among 30 patients (18%) with ≥ 20 rectal polyps at the time of total abdominal colectomy with ileorectal anastomosis, 8 patients (26%) underwent proctectomy and 3 patients developed rectal cancer (10%). Among 134 patients (82%) with < 20 polyps, 8 patients (6%) underwent proctectomy and 3 patients developed rectal cancer (2%). Number of rectal polyps at the time of total abdominal colectomy with ileorectal anastomosis was associated with the likelihood of proctectomy (OR 1.1, p < 0.001) but not incident rectal cancer (p = 0.3). LIMITATION: Retrospective data collection. CONCLUSION: Patients with familial adenomatous polyposis selected for total abdominal colectomy with ileorectal anastomosis by rectal polyp number have low rates of proctectomy and rectal cancer compared to historical controls. With appropriate selection criteria and surveillance, total abdominal colectomy with ileorectal anastomosis remains an important and safe treatment option for patients with familial adenomatous polyposis.