Comparison of the outcomes of ileal pouch-anal anastomosis and ileorectal anastomosis for patients with familial adenomatous polyposis: A systematic review and meta-analysis.

BACKGROUND: Familial adenomatous polyposis (FAP) is an inherited colorectal cancer syndrome for which ileorectal anastomosis (IRA) preserves the rectum but ileal pouch-anal anastomosis (IPAA) removes it. These procedures may influence the risk of desmoid tumors and involve trade-offs in oncologic protection and bowel function. This study compared the oncologic, desmoid, functional, and postoperative outcomes of IRA and IPAA in FAP. METHODS: PubMed, Embase, Scopus, and the Cochrane Library were searched for relevant studies. Primary outcomes were rectal or pouch-anal cancer and desmoid tumors. Risk of bias was assessed using the ROBINS-I tool, and certainty of evidence was assessed using the GRADE framework. Random-effects meta-analyses were conducted using pooled risk ratios (RRs), mean differences (MDs), and hazard ratios. RESULTS: Thirty-four studies involving 4,700 patients were included. Compared with IRA, IPAA was associated with lower risks of postoperative rectal and pouch-anal cancer (RR: 0.22, 95% CI: 0.09-0.54) but with a higher risk of desmoid tumors (RR: 1.58, 95% CI: 1.13-2.19). IPAA was associated with higher 24-hour incontinence (RR: 1.90, 95% CI: 1.24-2.92) and 24-hour stool frequency (MD: 1.89 stools/day, 95% CI: 1.29-2.49). Anastomotic stricture was more frequent after IPAA (RR: 2.91, 95% CI: 1.46-5.78), but major complications did not differ substantially between the procedures. CONCLUSIONS: IPAA is associated with greater long-term oncologic protection but worse bowel function and a higher desmoid tumor risk compared with IRA. These findings support individualized procedure selection based on surveillance feasibility to balance functional trade-offs, perioperative risk, and durability.