The Anatomy of Failures Following the Ligation of Intersphincteric Tract Technique for Anal Fistula: A Review of 93 Patients Over 4 Years

BACKGROUND: Although the ligation of intersphincteric tract technique is a promising sphincter-preserving option in managing anal fistulas, failures are still seen. OBJECTIVE: This study aimed to illustrate the patterns of failures and recurrences following the ligation of intersphincteric tract procedure for anal fistulas. DESIGN: This study is a retrospective review. SETTINGS: This study was conducted at the Division of Colorectal Surgery, University Surgical Cluster, National University Health System, Singapore, from April 2006 to September 2010. PATIENTS: Ninety-three patients were evaluated. INTERVENTIONS: All patients underwent the ligation of intersphincteric tract procedure for anal fistulas. MAIN OUTCOME MEASURES: Failure was defined as nonhealing of the surgical wound or fistula. Recurrence was defined as the reappearance of the fistula after initial healing. RESULTS: After a median follow-up of 23 (range, 1-85) weeks, there were 7 failures and 6 recurrences. The median time to healing was 4 (range, 1-12) weeks. The freedom from failure or recurrence at 1 year following the ligation of intersphincteric tract procedure was 78% (95% CI: 66%-90%). All 7 failures had discharge at the intersphincteric wound. Four had an unhealed internal opening, and 3 had isolated failures at the intersphincteric wound. Endoanal ultrasonography revealed a less complicated anatomy that enabled successful treatment with either local application of silver nitrate (n = 3) or fistulotomy (n = 4). All 6 recurrences had a demonstrable tract from the previous internal opening to an external opening with healing of the intersphincteric wound. The median time to recurrence was 22 (range, 15-33) weeks from the ligation of the intersphincteric tract procedure. Fistulotomy, repeat ligation of intersphincteric tract, or anocutaneous advancement flap procedure was successfully performed subsequently. CONCLUSION: In patients with early failures, the medialization of the external opening to the intersphincteric wound simplified subsequent management. All recurrences should be reevaluated and managed accordingly.