Plate 229

Pilonidal cysts and sinuses should be completely excised or exteriorized (Figure 3A and B). Acutely infected sinuses should be incised and drained, followed later by complete excision after the acute infection subsides. The more limited procedure of exteriorization (marsupialization) is effective when the sinus tract is well defined (Figure 3B). Regardless of the various surgical approaches, such lesions may recur.

In complicated sinuses with several tracts present, a dye such as methylene blue may be injected for better identification, although if a careful dissection is carried out in a bloodless field, the surgeon can identify the sinus tracts. It is important that this be done several days before operation to avoid excessive staining of the operative area, which may occur if the injection is done at the time of operation.

Light general anesthesia is satisfactory. The patient's position requires that special care be taken to maintain an unobstructed airway. Spinal anesthesia should not be used in the presence of infection near the site of lumbar puncture.

The patient is placed on his or her abdomen with the hips elevated and the table broken in the middle (Figure 1).

Two strips of adhesive tape are anchored snugly and symmetrically about 10 cm from the midline at the level of the sinus and pulled down and fastened beneath the table (Figure 2). This spreads the intergluteal fold for better visualization of the operative area. A routine skin preparation follows after the skin is carefully shaved.

An ovoid incision is made around the opening of the sinus tract about 1 cm away from either side (Figure 4). Firm pressure and outward pull make the skin taut and control bleeding.

An Allis forceps is placed at the upper angle of the skin to be removed, and the sinus is cut out en bloc (Figure 5). The subcutaneous tissue is excised downward and laterally to the fascia underneath. Great care is exercised to protect this fascia from the incision, as it offers the only defense against deeper spread of infection (Figure 6). Small, pointed hemostats should be used to clamp the bleeding vessels in order that the smallest amount of tissue reaction be incurred. Electrocoagulation may be used to control bleeding and to keep the amount of buried suture material to a minimum. Some prefer to avoid burying any suture material by using compression or electrocoagulation to control all the bleeding points. Extreme care should be taken in the dissection of the lower end of the incision, as many small, troublesome vessels are encountered frequently that tend to retract when divided. After careful inspection of the wound to make sure that all sinus tracts have been removed, the subcutaneous fat is undercut at its junction with the underlying fascia (Figure 7). This undercutting should extend only far enough to allow approximation of the edges without tension (Figure 8).

After all bleeding points are controlled, the wound should be thoroughly washed with saline. The chances for primary healing are greatly enhanced if the field is absolutely dry. If unexpected infection has been encountered, the wound should be packed open. In uncomplicated sinuses, the wound is closed after all bleeding is controlled. Rather than bury sutures, the skin can be closed and the dead space eliminated by a series of interrupted vertical mattress sutures (Figure 9). The suture is introduced 1 cm or a little more than the margins of the wound to include the full thickness of the mobilized flap of skin and subcutaneous tissue. A second bite includes the fascia in the bottom of the wound (Figure 9). The suture is then continued deep into the opposite flap. The suture is directed back to the original side as it passes back through the skin margins (Figure 10). When tied, this obliterates the dead space and accurately approximates the skin margins (Figure 11). The sutures should be placed at intervals of not more than 1 cm. Skin approximation must be very accurate, since even a small overlap may be surprisingly slow to heal in this area. A pressure dressing is applied with great care, and the sutures are allowed to remain in place for 10 to 14 days.

When the sinus appears small and in the presence of recurrence, a probe may be inserted into the sinus, and the skin and subcutaneous tissue divided (Figure 3A). The entire sinus, including any tributaries, must be laid wide open and all granulation tissue wiped away repeatedly with sterile gauze or a curette. The thick lining of the sinus forms the bottom of the wound. A wedge of subcutaneous tissue is excised to facilitate the sewing of the mobilized skin margins to the thick wall of the retained sinus. This ensures a cavity that can be dressed easily with a minimum of drainage as well as discomfort to the patient. The raw margins of the wound are held apart by a gauze pack until healing is complete (Figure 3B). This method has the advantage of being a procedure of less magnitude than complete excision. The period of hospitalization and rehabilitation is shortened and insurance against recurrence enhanced.

Complete immobilization of the area and protection against contamination are essential. Early ambulation is advisable, but sitting upon the incision in a hard chair is not. The patient should be encouraged always to sit on a cushion or to sit to the side on one buttock or the other. The diet is restricted to clear liquids for several days, followed by a low-residue diet to decrease the chances of contamination from a bowel movement. When the sinus is packed open or exteriorized, the patient is not immobilized. Regardless of the method used, frequent and repeated dressings are indicated to avoid possible early bridging of the skin with recurrence and prolonged discomfort and disability. The importance of keeping all hair removed from the intergluteal fold until healing is complete cannot be overemphasized. Depilatory agents may be used several times per month provided that pretesting for sensitivity to the agent has been negative.