EP770 - A Novel Technique for Repair of Transsphincteric Fistula in Ano

Purpose/Background: Transsphincteric anal fistulae pose a significant surgical challenge given their high recurrence rates and concern of sphincter injury. Current techniques often compromise between healing and continence preservation, with a constant search for a superior repair method. We evaluated the clinical outcomes of a novel anal canal anodermal advancement flap approach for transsphincteric fistulae in a retrospective cohort. The repair consists of obliteration of the primary fistulous orifice with 3-0 barbed unidirectional PDS suture, followed by tension-free approximation of the raised anal canal anoderm over the obliterated fistulous orifice with the same suture. This obliviates the need to create a perianal or endorectal mucosal advancement flap, decreasing operative time and tissue manipulation.

Methods/Interventions: We conducted a review of 25 charts of patients over the age of 18 who underwent the repair between February 2024 and May 2025 with at least 3 months of postoperative follow up. Fifteen patients (mean age 44 ± 19 years; 80% male) qualified for our study. Five patients (33%) had Crohn’s disease of which 3 were undiagnosed, and 60% had preoperative seton placement (median duration 4 months) which was removed intraoperatively. Mean OR time was 21 ± 12 min, with a median OR time of 17 min. Risk factors included BMI, smoking status, diabetes, HIV, other immunosuppression, prior fistula surgeries, and the location of the internal orifice. The primary outcome was clinical healing at three and six months, defined by cessation of drainage and no reintervention. Logistic regression adjusted for demographic, disease, and anatomical factors assessed predictors of recurrence.

Results/Outcomes: At three months, 86.7% (13/15) of patients achieved clinical healing; at six months, 73.3% (11/15) remained healed. Persistent drainage or recurrence occurred in 26.7% (4/15) by six months, (mean 102 ± 41 days postoperatively). On multivariable analysis including age, gender, BMI, smoking, diabetes, immunosuppression, Crohn’s diagnosis, steroid/biologic exposure, prior surgeries, preoperative seton use, and internal orifice location, only Crohn’s disease was significantly associated with recurrence (p = 0.039).

Five patients had Crohn’s disease, three of which were undiagnosed at the time of surgery and thereby untreated. Those were the same patients that also had a recurrence of their fistulae, while the other two that were being treated had a successful procedure.

Conclusion/Discussion: Our novel technique demonstrated at least promising short-term healing rates for transsphincteric anal fistulae, with acceptable recurrence rates. Crohn’s disease emerged as a key risk factor for recurrence. Prospective studies comparing this approach with other techniques such as anodermal or rectal mucosal advancement flap or the LIFT procedure are warranted to confirm long-term efficacy and safety.