Definitive seton management for transsphincteric fistula-in-ano: harm or charm?

The treatment of transsphincteric anal fistula requires a balance between eradication of the disease and preservation of faecal control. A cutting seton is an old tool that is now out of vogue for many surgeons. We hypothesized that the concept remains reliable and safe with results that exceed those reported for many of the more recently described methods.

A retrospective review was conducted of real-time electronic health records (single institution, single surgeon) of patients presenting during the 14 years between 2001 and 2014 with a transsphincteric anal fistula who were treated with a cutting seton. Excluded were patients with Crohn's disease, fistulae related to malignancy or a previous anastomosis and patients whose fistula was treated by another method including a loose draining seton. Data collection included demographics, duration of the disease, duration of the treatment, outcome and continence.

In all, 121 patients (80 men) of mean age 40.2 ± 12.2 years (range 18-76) with a mean follow-up of 5.1 ± 3.3 (1-24) months were included in the analysis. The median duration of symptoms was 6 (1-84) months; 36% had failed other fistula surgery, 12% had a complex fistula with more than one track and 35% had some form of comorbidity. The median time to healing was 3 (1-18) months; 7.4% required further surgery, but eventually 98% had complete fistula healing. The incontinence rate decreased postoperatively to 11.6% from 19% before treatment with 17/121 with pre-existing incontinence resolved and 8/107 new cases developing.

Despite its retrospective non-comparative design, the study has demonstrated that a cutting seton is a safe, well tolerated and highly successful treatment for transsphincteric anal fistula and is followed overall by improved continence. The results compare very favourably with other techniques.