EP513 - Efficacy of Dermal Advancement Flap for Treatment of Anal Fissure and Stenosis

Purpose/Background: When the conservative treatment of anal fissure fails, partial lateral internal anal sphincterotomy (IAS) remains the standard of care for an anal fissure with a hypertonic anal sphincter. In the setting of a normotonic or hypotonic anal sphincter, IAS is avoided because of the risk of fecal incontinence and the poor rate of fissure healing. This study reports on the outcomes of dermal advancement flaps for chronic anal fissure when anal sphincterotomy is contraindicated or broad scarring requires tissue interposition.

Methods/Interventions: This is a retrospective observational study. The Colon and Rectal Institute of the Lehigh Valley conducted a chart review of all patients who underwent dermal advancement flap procedures from January 2019 through October 2025. Indications for surgery included non-healing anal fissures, postoperative anal stenosis due to scarring, or broad-based anal ulcers. Types of repairs were divided into two groups: those with tissue advancements (TA) that simply mobilized skin or mucosa (U-flap, Transverse Anoplasty) versus rotational flaps (RF) maintaining subcutaneous tissue and blood supply (House Flap, V-Y Anoplasty). The primary outcome of overall symptom relief and healing rates were compared between groups. Re-operation indicated failure of the original procedure.

Results/Outcomes: A total of 34 patients underwent 40 procedures with dermal advancement flaps. Indications for surgery were chronic anal fissure in 23 patients (68%), anal stenosis in 5 (15%), and chronic ulcer in 6 (17%). Mean age was 44 years, and 25 of 34 patients were female (73.5%). Location of the lesion was primarily posterior (68%) compared to anterior (32%). All patients underwent enema preparation without full bowel preparation. 38 of 40 surgical procedures were performed with local anesthetic under MAC sedation and all as outpatient cases. Antibiotics were not routinely administered. Mean follow-up time was 70 days.

20 of 34 patients (59%) underwent rotational repair and the remaining 14 had tissue advancements (41%). Early wound breakdown occurred in 8 of 34 patients (23.5%). Only 1 of 20 rotational flaps dehisced (5%) compared to 7 of 14 tissue advancements (50%). Of these 8 patients, two were treated non-operatively and healed by secondary intention. The remaining 6 patients with non-healing wounds required re-operation.

5 patients had re-operation with a rotational flap and went on to full healing. One patient had a repeat tissue advancement flap which has not yet healed. With intention to treat, RF had the greatest efficacy, reporting a 95% healing rate and only 5% rate of re-operation. The TA repairs were much less successful, with an overall success rate of 42.9%.

Conclusion/Discussion: The use of House or V-Y rotational flaps can treat anal stenosis and anal fissure with a high rate of success when sphincterotomy is contraindicated. The risk of fecal incontinence minimized as the sphincter complex is untouched. Skin advancement for repair of anal fissure or stenosis in the setting of a normotonic or hypotonic sphincter is a poor choice with high rate of wound breakdown and re-operation, and this technique should be avoided.

Table 2
Repair Results
Table 1
Patient Characteristics