Adenoma and carcinoma in the anal transitional zone following hand-sewn versus stapled ileal pouch-anal anastomosis in familial adenomatous polyposis

Restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis (IPAA) is the standard surgical treatment for familial adenomatous polyposis (FAP) in our institution. Stapled and hand-sewn IPAA differ in the amount of retained rectal mucosa, influencing both adenoma risk and functional outcomes. In this retrospective cohort study, we compared oncological and functional outcomes between the two techniques. Consecutive patients with FAP who underwent RPC with IPAA at Seoul National University Hospital between 1994 and 2022 were included. The ATZ adenoma and cancer occurrence, operative time, and anorectal functional outcomes were compared between hand-sewn and stapled anastomosis groups. The cumulative incidence risk of adenoma recurrence was compared using the log-rank test. 89 patients were analyzed: 32 underwent hand-sewn and 57 underwent stapled IPAA. Median follow-up was 100 months in the stapled group and 79 months in the hand-sewn group. Stapled IPAA was associated with shorter operative time (220.6 vs. 332.9 min, p < 0.001), lower diverting ileostomy rate (78.9% vs. 96.9%, p = 0.027), and lower Wexner incontinence scores (1.54 vs. 3.43, p = 0.009). Adenomas or carcinomas at the ATZ were identified in 29.2% of patients, with a higher 5-year adenoma recurrence in the stapled group (20.1% vs. 3.2%, p = 0.02). Most adenomas were successfully managed endoscopically, with no cancer progression in the stapled group. Two cancers occurred in the hand-sewn group during long-term follow-up. Stapled IPAA offers advantages in operative efficiency and anorectal function, with higher adenoma recurrence manageable under surveillance. These findings suggest stapled IPAA may be a reasonable surgical option for FAP when coupled with diligent follow-up.