Lessons learned from an audit of 1250 anal fistula patients operated at a single center: A retrospective review

BACKGROUND: A complex anal fistula is a challenging disease to manage. AIM: To review the experience and insights gained in treating a large cohort of patients at an exclusive fistula center. METHODS: Anal fistulas operated on by a single surgeon over 14 years were analyzed. Preoperative magnetic resonance imaging was done in all patients. Four procedures were performed: fistulotomy; two novel sphincter-saving procedures, proximal superficial cauterization of the internal opening and regular emptying and curettage of fistula tracts (PERFACT) and transanal opening of intersphincteric space (TROPIS), and anal fistula plug. PERFACT was initiated before TROPIS. As per the institutional GFRI algorithm, fistulotomy was done in simple fistulas, and TROPIS was done in complex fistulas. Fistulas with associated abscesses were treated by definitive surgery. Incontinence was evaluated objectively by Vaizey incontinence scores. RESULTS: A total of 1351 anal fistula operations were performed in 1250 patients. The overall fistula healing rate was 19.4% in anal fistula plug (n = 56), 50.3% in PERFACT (n = 175), 86% in TROPIS (n = 408), and 98.6% in fistulotomy (n = 611) patients. Continence did not change significantly after surgery in any group. As per the new algorithm, 1019 patients were operated with either the fistulotomy or TROPIS procedure. The overall success rate was 93.5% in those patients. In a subgroup analysis, the overall healing rate in supralevator, horseshoe, and fistulas with an associated abscess was 82%, 85.8%, and 90.6%, respectively. The 90.6% healing rate in fistulas with an associated abscess was comparable to that of fistulas with no abscess (94.5%, P = 0.057, not significant). CONCLUSION: Fistulotomy had a high 98.6% healing rate in simple fistulas without deterioration of continence if the patient selection was done judiciously. The sphincter-sparing procedure, TROPIS, was safe, with a satisfactory 86% healing rate for complex fistulas. This is the largest anal fistula series to date.