Two-Stage Complete Deroofing Fistulotomy Approach for Horseshoe Fistula: Successful Surgery Leaving Continence Intact.

Purpose: Surgery of the horseshoe fistula is challenging due to its complex configuration and sphincter muscle involvement. Complete deroofing fistulotomy for horseshoe fistula is highly curative with the eradication of all fistulous lesions but has been discredited for its high incontinence rate. It was replaced with the more conservative Hanley's procedure leaving the lateral tracts intact, despite its issue of recurrence. Our study aimed to report the outcomes of a procedure dividing complete deroofing fistulotomy for horseshoe fistula into 2 stages to avoid impairment of sphincter function.

Methods: We retrospectively reviewed 139 patients who underwent surgery for horseshoe fistula using the 2-stage complete deroofing fistulotomy method between 2014 and 2017. The first surgery deroofed the lateral tracts with an arch-like incision severing the anococcygeal ligament. The primary lesion was also drained and curetted. A seton was placed in the primary tract which was laid open in the second surgery after the lateral wound had partially healed.

Results: Recurrence was observed in 12 patients. All were superficial recurrences except for 1, in which recurrence was confirmed in the primary lesion. Those with blind intersphincteric upward extensions had a significantly higher recurrence rate. Furthermore, patients who resided far from the hospital and could not make visits for frequent wound inspections also had a significantly higher recurrence rate. No patient had any continence issues at the end of the follow-up period.

Conclusion: Managing horseshoe fistula with the 2-stage deroofing fistulotomy approach allows for eradication of the fistula tract without compromising anal sphincter function.