Seton or glue for trans-sphincteric anal fistulae: a prospective randomized crossover clinical trial

Fibrin glue treatment of anal fistulae has been proposed to minimize the risk of faecal incontinence but its acceptance by coloproctologists is still poor because the published data is controversial. Therefore, we carried out a prospective randomized crossover trial comparing treatment with a commercial fibrin glue to classical seton treatment, with healing rate, hospital stay, healing time, faecal incontinence and postoperative pain as study outcomes.

Sixty-four homogeneous patients with trans-sphincteric anal fistulae referred to seven colorectal units were randomized to undergo fibrin glue (39 patients) or seton (25 patients) treatment. Patients failing to heal after treatment with fibrin glue were re-randomized to undergo a second injection with glue or seton treatment.

Sixty-two of the 64 patients completed the minimum 1-year follow-up period. Twenty-one of 24 patients healed in the seton group compared with 15/38 in the fibrin glue group (P = 0.0007). The 23 failures after glue treatment were re-randomized to have a second glue injection (eight patients) or a seton treatment (15 patients). Four of the eight (50%) patients treated with a second injection of glue, and nine out of the 15 (60%) patients in the seton group, healed. Patients treated with fibrin glue reported less postoperative pain and had a shorter hospital stay than patients treated with a seton; furthermore, faecal continence and anal manometry significantly worsened after seton treatment.

Seton treatment has a significantly higher probability of success compared with fibrin glue treatment but poses a higher risk of faecal incontinence. Fibrin glue could be considered as a first line of treatment for patients at risk of faecal incontinence or other comorbidities.