Perianal abscesses and fistulas

Abstract

In a five and one-half year period, 1023 patients with anorectal abscesses and fistulas were treated. Under regional anesthesia the abscesses were unroofed and debrided and a primary fistulotomy was performed whenever a low fistula was identified. In 355 (34.7 per cent) an internal fistulous opening was demonstrated at the time of abscess drainage. Thirty-two patients had suprasphincteric fistulas and underwent two-stage fistulotomy using a seton. Perianal abscesses were encountered in 42.7 per cent of the patients, followed by ischiorectal (22.7 per cent), intersphincteric (21.4 per cent), and supralevator (7.33 per cent). The patients with supralevator and intersphincteric abscesses had a high incidence of fistula identified during abscess drainage. The recurrence rates were 3.7 per cent in the group with abscess drainage only and 1.8 per cent in the group that had primary fistulotomy along with abscess drainage. The follow-up period averaged 36 months. To accomplish adequate drainage and identify the deeper components and associated fistulous opening (34.7 per cent of the entire group), careful examination under regional anesthesia is recommended. Early aggressive treatment of an anorectal abscess and fistula significantly reduces the possibility of recurrent abscesses and/or the need for further surgery.

Anorectal Infection: Abscess-Fistula

“…In a large series of anorectal abscess treated in the operating room with simultaneous search for an anorectal fistula, the incidence of fistula was 34%. 6 In two other singleinstitution series, the incidence of fistula following an abscess was 26% and 37%. 7,8 If one is to extrapolate from fistula numbers, the incidence of anorectal abscess falls between 68,000 and 96,000 per annum in the United States.…”

“…11 In adult patients the male to female ratio is 2:1. 4,6,12 Race There are few epidemiologic studies regarding the racial distribution of anal fistulas. In a series of 474 patients from Cook County Hospital in Chicago, 92% of the patients were black; this closely corresponded with the racial distribution of patients at that time and in that Hospital.…”

“…With unroofing and primary fistulotomy, when deemed safe, the incidence of recurrent infection was only 3.7%. 6 …”

“…Others have reported a good success rate with primary fistulotomy. 6 If the surgeon is not familiar with anorectal anatomy or pathology, anal fistula should not be searched for. However, an experienced surgeon may probe the corresponding anal crypt gently, looking for a fistula.…”

“…If a fistula is identified and is quite superficial, primary fistulotomy may be attempted. 6 If the surgeon is not certain of the thickness of the sphincter muscle involved in the fistula, a loose seton of braided, nonabsorbable suture should be inserted into the fistula tract, tied loosely to act as a drain as well as a marker for future fistula surgery. 21 In horseshoe abscesses, the deep postanal space should be unroofed.…”