Abstract
High trans-sphincteric fistulas, involving the upper two-thirds of the external sphincter, remain a surgical challenge because incontinence may result from the division of muscle involving more than one-third of the sphincter. The principles of anal fistula surgery are to eliminate the fistula, prevent recurrence and preserve sphincter function. In contrast with fistulotomy for low anal fistulas, a well-accepted, simple, safe, and efficient method is still lacking for high anal fistulas. Seton techniques still occupy an important position in the treatment of high anal fistulas. The seton works by several mechanisms: (1) it helps in draining pus and controlling sepsis prior to definitive treatment; (2) it stimulates fibrosis and acts as a marker of the fistula tract for sphincter sparing procedures such as fistula plug, fibrin glue and ligation of intersphincteric fistula tract (LIFT); and (3) the tight (cutting) seton promotes slow transection of the external sphincter muscle as a result of pressure necrosis with minimal separation of the cut ends. Long-term seton drainage is a simple and efficient procedure in treating high anal fistulas in Crohn's disease. This article describes the current options available for management of anal fistula with setons. When a patient presents with anal fistula, it is important to determine the level of fistula, involvement of sphincters (high vs low transphincteric), abscess or local sepsis and the etiology. For low fistula involving less than a third of the sphincters, primary fistulotomy can be performed. For high transphincteric fistula with abscess and local sepsis, a loose seton to act as drainage seton or a drainage tube seton should be placed. Once the abscess has resolved than for a crypt glandular fistula the treatment decision involves the use of sphincter sparing vs sphincter cutting options. Setons for such treatment can be considered either as a cutting or loose seton after discussing the individual merits with the patients. Cutting seton can be used as a single stage or multi-stage procedure. Currently cutting setons are not in much use in the developed countries because of the pain associated with treatment, uncontrolled cutting of sphincter muscles and a higher rate of incontinence. If the patient is willing to try for a prolonged treatment option then he can be offered the long term loose seton. For patients who want to opt for sphincter saving surgery the loose setons are generally left in the fistula tract for 4-6 weeks. Also patient who had started on long term loose seton, but did not want to continue with loose seton, can be considered for one of the sphincter sparing surgery. Patients with Crohn's disease have a higher risk of recurrence. Once the perianal sepsis is controlled with loose drainage setons/ drainage tubes, consideration should be given for treatment with biological agents such as infliximab. After the disease and sepsis is under control these patient can choose between long term loose seton or sphincter sparing surgeries. © 2013 by Nova Science Publishers, Inc. All rights reserved.