Full mucosal proctectomy initiated below the dentate line may prevent the development of a perianal fistula after ileal pouch-anal anastomosis for ulcerative colitis.

BACKGROUND

Long-term functional results of ileal pouch-anal anastomosis (IPAA) with mucosal proctectomy (MP) for ulcerative colitis (UC) are satisfactory but may be compromised by perianal fistulae.

METHODS

We analyzed the effect of the level of MP (above or below the dentate line) on the risk of perianal fistulae in 151 patients undergoing IPAA for UC.

RESULTS

A postoperative perianal fistula occurred in 12 patients (10 with MP from the level above the dentate line and 2 below). Patients developing perianal fistulae after IPAA were significantly younger at IPAA (23 vs. 32 years, p = 0.015). Age <25 years at UC onset (hazard ratio, HR, 3.5, p = 0.041), age <30 years at IPAA (HR 4.3, p = 0.015) and MP above the dentate line (HR 4.7, p = 0.010) were significant risk factors for perianal fistulae after IPAA. Multivariate analysis showed that age <30 years at IPAA (HR 4.4, p = 0.018) and MP above the dentate line (HR 6.0, p = 0.012) were significant risk factors.

CONCLUSION

IPAA with MP below the dentate line for UC might reduce the risk of postoperative perianal fistulae.