To observe the clinical effect of one-stage extra-dissection and loose seton operation in the treatment of complex anal fistula combined abscess.

From September 2008 to October 2015, eighty-eight cases of complex anal fistula were randomly divided into two groups, treatment group of 53 cases with one-stage extra-dissection and loose seton operation, control group of 35 cases with the first stage abscess dissection and the second stage extra-dissection and loose seton operation. The data between two groups including types of fistula, preoperative and postoperative anal functional status (Wexner score assessment), hospitalization time, cure time, recurrence rate and complications were compared.

The most common type of fistula was the anal intersphincteric fistula. The apparent healing rate of treatment group and control group was 92.5% and 91.4%, respectively, with no significant difference between the two groups (χ²=0.030, P=0.862). Preoperative and postoperative incontinence average credit of two groups were 1.8±1.3 and 1.9±1.3, 1.7±1.5 and 2.0±1.2 (t=0.332, 0.364, both P>0.05). Wexner incontinence scores were in the range of 0-5. There was no significant difference in complication rates (χ²=0.133, P=0.998). For a 0.5-4 years follow up, the two groups showed no difference in recurrence rate (7.5% vs 8.6%, χ²=0.030, P=0.862). The hospital stay and wound healing time of treatment group was (5.9±0.3) d and (6.2±1.5) d, while the control group was (20.3±1.3) d and (25.2±1.2) d, with a significant difference (t=24.351, 16.523, both P<0.01).

Compared with traditional stages, the one-stage extra-dissection and loose seton operation has advantages of less pain, shorter course, better protection of anal function for treating complex anal fistula combined abscess.