Randomized clinical trial comparing simple drainage of anorectal abscess with and without fistula track treatment

Abstract

Background and aims. Anal abscess is a frequent acute proctological disorder and whether the underlying fistula should be treated at the same time when the abscess is drained remains controversial. We examined indications for drainage alone versus drainage plus fistulotomy in terms of recurrence and continence.

Patients and methods. We carried out a randomized prospective study of 200 consecutive patients with anal abscess. One group received drainage alone, while in the other group drainage plus fistulotomy was performed when a subcutaneous-mucosa, low transsphincteral, or intersphincteral fistula was found. Delayed progressive fistulotomy with suture threads was performed in cases of high transsphincteric or suprasphincteric fistula.

Results. The internal opening of the fistula track was found in 83% of the patients. The recurrence rate was related to the surgical technique employed: 29% in the group with drainage alone and 5% in the group for which treatment of the fistula track was attempted. The incontinence rate was also related to the surgical option. In those receiving drainage and treatment of the fistula track incontinence was restricted mostly to patients with delayed fistulotomy (36.7%), compared to 2.8% of patients when simple fistulotomy was performed. There was no incontinence in the drainage alone group.

Conclusion. Drainage of anal abscess with fistulotomy can be safely performed in cases of subcutaneous, intersphincteral, or low transsphincteral fistulae with a minimal recurrence rate. However, drainage alone and posterior treatment of the fistula track is recommended for high transsphincteral or suprasphincteral fistulae.