How to Insert a Draining Seton Correctly

Ambulatory seton placement followed by fistulotomy: efficacy and safety for perianal fistula treatment

PURPOSE

To evaluate the efficacy and safety of ambulatory seton placement followed by superficial fistulotomy as treatment of perianal fistula.

METHODS

Retrospective observational analysis of patients with cryptogenic perianal fistula aged 18-90 years, followed in a central hospital proctology consultation between 2006 and 2017. Data were obtained through clinical record's analysis. Fistula was characterized, using Parks Classification. A probe was passed through the fistula tract, followed by a seton, which remained in situ until superficial fistulotomy was possible.

RESULTS

Ninety-six patients were included (66.67% males, mean age 56 ± 15 years old). Nineteen patients (19.89%) had previous history of perianal fistula and 14 (14.58%) previous anorectal surgery. Seventy-four patients (78.72%) were submitted to fistulotomy, three (3.19%) had seton fistulotomy and one had no seton progression. Intention-to-treat and per-protocol efficacy analyses were 80.2 and 98.7%, respectively. Among the 74 patients who completed the procedure, type of fistula and time with seton were distributed as followed: 47 (63.51%) intersphincteric fistula (15 ± 31 weeks), 26 (35.14%) transsphincteric fistula (32 ± 47 weeks), one (1.35%) suprasphincteric fistula (11 weeks). Previous fistula was associated with a longer time with seton (P = 0.018). Incontinence was reported in two (2.7%) patients, who had previous perianal fistula or anorectal surgery. Two patients (2.7%) had recurrence after fistulotomy.

CONCLUSION

Placement of seton followed by superficial fistulotomy in an ambulatory setting is a safe and effective method for simple low perianal fistula treatment. Incontinence rate may be higher in patients with previous perianal fistula or anorectal surgery.