Complex anal fistula surgery

An anal fistula is called complex when its tract crosses a large part of the anal muscle (sphincter), has branches, keeps recurring, or occurs in a particular setting (Crohn's disease, previous anal surgery, a fistula at the front of the anus in women). In these situations, simply laying the tract open could affect continence. Treatment is therefore carried out in stages. The first stage often involves draining the infection and placing a seton: a soft thread passed through the tract and tied outside, which provides continuous drainage and calms the inflammation for several weeks. In a second stage, the surgeon chooses the most suitable technique to close the tract while preserving the sphincter: an advancement flap that covers the internal opening, ligation of the tract between the muscles (LIFT technique), laser closure of the tract, or keeping the seton in place for longer. The choice depends on the anatomy of the fistula, as shown on pelvic MRI. At Clinique Pasteur Tunis, these fistulas are treated step by step, with appropriate imaging and, when needed, in coordination with the gastroenterologist. Patients are informed at each stage of the aims and timing of treatment.