Fistulotomies are performed by unroofing the track between the internal and external openings (Fig. 32.2). Reported recurrence rates are low. A zero recurrence rate was reported by a single surgeon case series of 38 patients over 5 years [17]. A more recent multicenter retrospective review of 537 patients undergoing fistulotomy for low perianal fistula reports a primary healing rate of 83.6 %, 81.7 % for transsphincteric, and a secondary healing rate of 90.3 % after treatment for recurrence [4]. Incontinence rates following fistulotomy depends on both the amount of muscle divided at the time of operation as well as any preexisting sphincter damage. Although Gottgens et al. reported a major incontinence rate of 28 %, the risk of incontinence in simple fistulas is very low. Abramowitz et al. described only a 1-point increase in Wexner score postoperatively after 1 year in patients undergoing fistulotomy for low fistula with a reported score ≤5 in 69 %. However, the median Wexner score worsened by 3 points for patients with high transsphincteric fistulas, which was statistically significant [5].

Setons are the oldest recorded surgical approach to fistula management, first described by the Indian Surgeon Shushruta 1200 BC. A seton serves to drain sepsis, enables preservation of the sphincter mechanism and can prepare the patient for a two-stage procedure. A draining seton prevents the internal and external orifices of the fistulas from closing, allowing infection to dissipate. Cutting setons enable slow division of a fistula tract by pressure necrosis of the intervening tissue. Because the division is slow, it is postulated that this leads to greater fibrosis without a significant gap in the sphincter complex.