Cyanoacrylate Glue Insertion Versus Seton Placement in the Management of Trans-sphincteric Anal Fistula: A Prospective Comparative Study.

Anal fistula is a common perianal condition associated with significant morbidity, recurrence, and risk of incontinence. Traditional surgical techniques such as seton placement are effective but are often associated with pain, prolonged healing time, and extended hospitalisation. Cyanoacrylate glue has emerged as a minimally invasive sphincter-preserving alternative. This prospective comparative study was conducted at Sri Ramachandra Institute of Higher Education and Research, Chennai, India, between June 1, 2023, and December 31, 2024. Fifty patients with uncomplicated trans-sphincteric fistula (St James University Hospital classification grade 3) were randomly allocated to receive either seton placement (n=25) or cyanoacrylate glue insertion (n=25). Primary outcomes included postoperative pain measured by visual analogue scale (VAS), duration of hospital stay, healing time, healing rate, and anal incontinence assessed by the Wexner continence score. The mean age was 45.3 years (SD 8.2) in the seton group and 39.1 years (SD 7.6) in the glue group. Both groups were comparable in demographic characteristics. VAS pain scores were significantly lower in the glue group compared with the seton group (mean 2.0 (SD 0.8) vs 3.4 (SD 1.1); p<0.001). Hospital stay was shorter in the glue group (2.6 days (SD 1.2) vs 5.3 days (SD 1.8); p<0.001). Healing time was significantly reduced with cyanoacrylate glue (2.75 weeks (SD 1.1) vs 5.79 weeks (SD 2.3); p<0.001). Healing rates were 96% (24 of 25) in the seton group versus 80% (20 of 25) in the glue group (p=0.189). No anal incontinence was observed in either group at three-month follow-up. Cyanoacrylate glue insertion offers a safe, minimally invasive alternative to seton placement for carefully selected patients with uncomplicated trans-sphincteric anal fistula, with significant advantages in pain reduction, shorter hospital stay, and faster healing. Although healing rates were lower with glue (80% vs 96%), this difference was not statistically significant, and the study was underpowered to detect this difference in healing rate as a secondary endpoint. All treatment failures were successfully managed with salvage fistulotomy or repeat glue application without morbidity. Larger randomised controlled trials adequately powered for healing rate as a co-primary endpoint are warranted to confirm long-term efficacy.