Results of surgical treatment in chronic anal fissure complicated by abscess or fistula in a retrospective cohort of patients.

We report the results of the surgical treatment of anal fissures complicated by abscess or fistula and formulate hypotheses about their nature. Among patients operated between 2012 and 2020 for anal fissure resistant to medical therapy, those affected by septic complications were selected for our inquiry. Surgical treatment consisted in the drainage of the sepsis, fissurectomy, posterior sphincterotomy and anoplasty. Intra-sphincteric fistulas were removed with the fissure, whereas low trans-sphincteric tracks, including horseshoe fistulas, were partially opened and curetted. Patients were followed on post-operative days 7-10 and then until healing. Pre- and post-operative Visual Analog Scale (VAS) and Cleveland Clinic Incontinence Score (CCIS) scores were compared. Recurrence rates of disease were recorded. We operated 988 patients and 55 of them showed local sepsis (5.5%) complicating anal fissures. There were 23 abscesses and 32 fistulas. Of these latter, 17 were intra or inter-sphincteric (2 anterior) and 15 low trans-sphincteric (6 horseshoes). Pre-operative VAS score was 7.6 ± 0.9 (mean ± sd), CCIS was 0.1 ± 0.5. Complete healing occurred after a median of 6 weeks (range 3-14 weeks). Mean VAS score dropped to 2.3 ± 0.6 at first follow-up visit and CCIS rose to 0.4 ± 0.2. After a mean of 56.4 months, 41 patients agreed to a visit and 14 were interviewed by phone. At office visit no disease recurrences were observed; pain and continence scores were within normal ranges in all patients. Abscess and fistula in anal fissures are not frequent and may represent a different disease from cryptoglandular fistulas. Surgical treatment achieves higher success than that reported for cryptoglandular fistulas.