How is the seton procedure for anal fistula performed?

Seton placement for anal fistula is the primary method for treating high transsphincteric or suprasphincteric anal fistulas. The procedure involves the following steps: 1. Preoperative preparation: The patient is placed in the lithotomy or lateral decubitus position. The perianal skin is disinfected and sterile drapes are applied. Anesthesia is commonly achieved via spinal, sacral canal, or epidural anesthesia to ensure smooth surgical progression. 2. Exploration and seton placement: After the anesthesia takes effect, the physician gently inserts a probe through the external opening of the fistula, carefully passing it through the fistulous tract and out the internal opening. Once an adequate length of the probe extends beyond the internal opening, it is bent and pulled out through the anus. An elastic rubber band is then tied to the end of the probe, which is subsequently pulled completely out through the anus, drawing the rubber band tightly through the fistulous tract. 3. Ligation and incision: The physician makes an incision through the epidermis and subcutaneous tissue between the internal and external openings of the fistula. A portion of the skin covering the fistula is excised, and the rubber band is tightened. Close to the perianal skin, the rubber band is double-ligated using hemostatic forceps to ensure it is securely embedded within the skin incision. 4. Postoperative management: After completing the ligation, the excess portion of the rubber band is cut off. The wound is compressed with oiled gauze and dressed with appropriate bandages. Regular dressing changes are required postoperatively, and attention should be paid to the status of rubber band sloughing. Typically, the fistulous tissue is severed and shed within 7–10 days after surgery due to the cutting action of the rubber band. If the rubber band does not fall off spontaneously, it should be tightened further to promote ischemic necrosis and eventual sloughing of the tissue. If you have any concerns, please consult your physician.