Management of anorectal horseshoe abscess and fistula.

Over a 10-year period 69 patients were treated consecutively for posterior and anterior horseshoe abscesses and fistulas. Fifty-nine patients had posterior and ten had anterior abscesses or fistulas. There were 52 patients with acute abscess. Treatment consisted of incision and drainage, incision and drainage with primary fistulotomy, incision and drainage with primary fistulotomy and counter-drainage, and incision and drainage with insertion of seton. Seventeen patients with chronic fistulas were treated by primary fistulotomy with curettage, or incision and drainage with insertion of seton. Patients were followed from three months to ten years with a mean follow-up of three years. No incidences of incontinence were reported in this series. The overall rate of recurrence was 18 percent, and included only patients with posterior abscesses and fistulas. Recurrence was related to the failure to maintain prolonged drainage in the midline after primary fistulotomy. The use of seton for delayed fistulotomy appears to promote wound drainage and precludes premature wound closure. More liberal use of the seton in the treatment of horseshoe abscesses and fistulas is advocated.