Needle-knife stricturotomy in Crohn's-related anorectal strictures: a prospective study of long-term outcomes, safety profile, and risk factors for recurrence.

Abstract

Background: Anorectal stricture is a challenging complication of Crohn's disease (CD). Endoscopic needle-knife stricturotomy (NKSt) has emerged as a minimally invasive treatment option, but its long-term outcomes and factors influencing recurrence remain underexplored.

Objectives: This study aimed to prospectively evaluate the long-term efficacy, safety, and risk factors for recurrence after NKSt for primary high-grade anorectal strictures in CD.

Design: Single-center prospective cohort study.

Methods: Between October 2020 and September 2023, 54 consecutive CD patients with primary high-grade anorectal strictures undergoing NKSt were enrolled. The primary endpoint was stricture recurrence requiring re-intervention. Risk factors were analyzed using univariable and multivariable Cox proportional hazards regression. Recurrence-free survival was estimated with the Kaplan-Meier method. A restricted cubic spline model within the Cox framework was employed to explore the nonlinear relationship between stricture length and recurrence.

Results: The median follow-up was 24 months (interquartile range (IQR): 6-43). Immediate technical success was achieved in all patients (100%), and 38 patients (70.4%) reported symptomatic improvement at 3 months. Recurrence occurred in 20 patients (37.0%). Multivariable analysis identified stricture length (hazard ratio (HR) 1.184 per cm increase, 95% confidence interval (CI): 1.015-1.380; p = 0.032), the presence of an ostomy (HR 3.901, 95% CI: 1.406-10.823; p = 0.009), and concurrent biologic therapy (HR 0.177, 95% CI: 0.057-0.546; p = 0.003) as independent predictors of recurrence. In univariable analysis, NKSt combined with bleomycin injection was associated with a lower recurrence risk compared to NKSt alone (p = 0.027).

Conclusion: NKSt is an effective and safe treatment for primary high-grade anorectal strictures in CD, although recurrence is common. Stricture length, ostomy status, and the use of biologic agents are independent predictors of recurrence, while concomitant bleomycin injection may reduce recurrence risk. These findings can inform individualized treatment strategies and highlight the need for validation in larger, multicenter trials.