IPAA Is More "Desmoidogenic" Than Ileorectal Anastomosis in Familial Adenomatous Polyposis

BACKGROUND: Desmoid disease is a leading cause of morbidity and mortality in patients with familial adenomatous polyposis. Abdominal desmoid disease usually follows total proctocolectomy with IPAA or total abdominal colectomy with ileorectal anastomosis. Sex, extraintestinal manifestations, and a 3'-mutation location have been identified as risk factors, but surgical risk factors are poorly understood. We hypothesized that pouch construction creates a higher risk of desmoid formation due to the increased stretch of the small-bowel mesentery. OBJECTIVE: This study aimed to investigate the surgical risk factors for desmoid formation. DESIGN: This was a retrospective, single-center, registry-based cohort study. SETTINGS: This study was conducted at a single academic institution with a prospectively maintained hereditary colorectal cancer database between 1995 and 2015. PATIENTS: All patients with familial polyposis (total 345) who underwent either proctocolectomy with a pouch or colectomy with an ileorectal anastomosis during the study period and met inclusion criteria were selected. MAIN OUTCOME MEASURES: The development of symptomatic abdominal desmoid disease was the primary end point. Associations between desmoid formation and resection type, surgical approach, and other patient factors were analyzed. RESULTS: A total of 172 (49%) patients underwent proctocolectomy/ileoanal pouch, whereas 173 (51%) underwent total colectomy/ileorectal anastomosis. Overall, 100 (28.9%) developed symptomatic desmoids after surgery. On univariable analysis, open surgery and pouch surgery were associated with desmoid development, along with extracolonic manifestations, family history of desmoids, mutation location, and a high desmoid risk score. On multivarible analysis, proctocolectomy with pouch was most strongly associated with desmoid disease (p<0.01). LIMITATIONS: This study was limited by its retrospective nature, the lack of uniform desmoid screening, and the variable duration of follow-up. Unanalyzed confounding factors include polyposis severity and number of surgeries. CONCLUSIONS: Patients with polyposis who underwent total proctocolectomy with pouch by any approach had significantly greater risk of developing desmoid disease than total colectomy with ileorectal anastomosis, even when accounting for other risk factors.