If a large transsphincteric fistula involving a significant amount of external sphincter muscle is present, a seton should be placed. The probe is first passed from the external opening to the internal opening, and a 0 silk suture is tied around the groove in the probe (Figure 14). The probe with the suture is then pulled back through the fistula track, and the 0 silk suture is tied tightly around the muscle. All fat and skin are removed leaving the seton compressing sphincter muscle only. Silk is an irritant, and with time the silk will cut through the sphincter muscle. However, the fistulotomy will be performed incrementally giving time for the sphincter to heal. The fistula is slowly drawn out by the seton. This protects against incontinence, by preventing the sphincter muscle from separating, as would happen during a fistulotomy. A non-cutting seton using a vessel loop is indicated in chronic perianal disease.
The patient may be out of bed as soon as the anesthesia has worn off. The patient is allowed a light diet, and there is no attempt to restrain bowel movements. Stool softeners are prescribed. Sitz baths may be started on the second day following operation. Patients may be discharged the day of surgery and are seen within one week.
An alternative therapy for a complex fistula is an endorectal advancement flap (Figure 15). A flap with mucosa and submucosa is created to include the internal opening (Figure 16). The dissection is carried far enough proximal until the flap can be advanced distally without tension. The internal opening is excised, and then the flap is matured to the intersphincteric groove (Figure 17). The external sphincter may be plicated to close the fistula opening and then the flap is sutured to the intersphincteric groove with interrupted absorbable sutures (Figure 17). This effectively treats a complex fistula in ano with minimal risk of injury to the sphincter muscles.
Fissure in ano is a common painful condition that can be found in children and adults alike. These wounds usually heal spontaneously in children but may require operative correction in adults. It is usually caused by constipation or a large traumatic bowel movement, and it is almost always located posterior. The fissure, which runs between the dentate line and anal verge, if deep enough exposes the internal sphincter muscle. This causes considerable spasm and pain. Chronic fissures may be associated with a hypertrophied anal papilla and a skin tag. Over a period of time, the internal sphincter muscle hypertrophies, becoming more effective in keeping the wound open, and preventing spontaneous closure of the fissure. Topical salves and fiber are usually effective early on. Once the wound becomes chronic, surgical repair is usually necessary.
No preoperative preparation is necessary. The cleaning enema, which is such an excruciating procedure to the patient, is omitted.
Spinal, epidural, or local anesthesia is satisfactory.
The field is prepared with local antiseptic solution. No attempt is made to dilate the canal and irrigate the rectum.
The patient is placed in the position as shown and prepped and draped in the usual fashion. The prone jack-knife position may be used. A Hill-Ferguson retractor is placed in the anal canal, and the anal canal is inspected. The fissure is usually posterior and may be associated with a right posterior hemorrhoid (Figure 18). The fissure and the hemorrhoid, if necessary (Figure 19), are excised and the anal mucosa and anoderm closed with a running 2-0 chromic suture (Figure 20). A lateral internal sphincterotomy is performed to reduce sphincter spasm. A separate incision is then made in the left lateral position, again excising the hemorrhoid in that location if necessary, to expose the hypertrophied internal sphincter muscle. A partial lateral internal sphincterotomy is done in this position. This wound is closed with a running 2-0 chromic stitch.
The procedure may be done as a closed technique. With the finger in the anal canal, an 11-blade is inserted into the intersphincteric plane staying below the dentate line (Figure 21). The blade is then moved medially, dividing the inferior one-third to one-half of the internal sphincter (Figure 22).
An open technique may be done. A skin incision is made (Figure 23). A hypertrophied band of internal sphincter is freed and elevated (Figure 24). The internal sphincter is then partially divided (Figure 25). The wound is left open. The sphincterotomy is done in the lateral position to avoid creating a keyhole deformity, a complication of the procedure that can be challenging to correct. This procedure removes the chronic fissure in ano and releases the tension on the anal canal sufficiently enough to allow the fissure to heal.
Patients are allowed out of bed and encouraged to move their bowels as soon as possible after operation. Daily sitz baths and daily rectal examinations are indicated to ensure that granulations do not build up and protrude into the anal canal. The patient should be kept under weekly observation after discharge until healing is complete.