Pilonidal Disease Treatment & Management

The treatment of pilonidal sinuses with phenol injections^{[5, 6]} is more common in Europe than in the United States. Chronic pilonidal disease and acute pilonidal abscess (after drainage) may be managed by phenol injection. Eighty percent phenol is injected into the sinus, left there for 1 minute, and then expressed out of the cavity. The sinus is then curetted. This may be repeated as many as 3 times, for a total of 3 minutes of phenol exposure at 1 treatment. The treatments may be repeated every 4-6 weeks as necessary, as wound healing progresses. Paraffin jelly may be used to protect the skin from the phenol, which destroys the epithelium.

Phenol sterilizes the sinus tract and removes embedded hair. Phenol injections may be combined with local excision of the sinus. Wound healing usually requires 4-8 weeks. The incidence of recurrence is reported to be approximately 9-27%, which is similar to the incidence following simple excision and packing open the wound. Because of the intense local inflammatory response after the phenol injection, patients usually stay in the hospital overnight. Thereafter, the patient is allowed to return home, with instructions to bathe daily and keep the area shaved. Dressings are used for comfort.

Pilonidal disease is divided into 3 categories to better determine the most appropriate surgical management. These 3 categories are (1) acute pilonidal abscess, (2) chronic pilonidal disease, and (3) complex or recurrent pilonidal disease.

Pilonidal abscess

A pilonidal abscess is managed by incision, drainage, and curettage of the abscess cavity to remove hair nests and skin debris. This can be accomplished in the surgical office or in the emergency department, under local anesthesia.^[7] If possible, make the drainage incision laterally, away from the midline. Wounds heal poorly in the deep, intergluteal natal cleft, which allows frictional movement of one buttock over the other. The wound should be cleansed daily in the shower or with a sitz bath. Paying close attention to hygiene and hair shaving of the surrounding area is important in preventing hair from penetrating the healing scar.

This meticulous treatment of the diseased area should continue for approximately 3 months, even after the wound has completely healed. In more than 90% of cases, the wound heals completely in approximately 1 month. In approximately 60% of patients, incision and drainage without curettage results in wound healing within 10 weeks. Of these patients, 40% develop a recurrent pilonidal sinus, requiring further treatment.

Inform patients that drainage of the abscess is not a curative procedure. Some studies have shown that as many as 85% of patients require further surgical treatment. Excising the pilonidal pit at the time of abscess drainage reduces the recurrence rate to 15%. The difficulty with doing this is that the pilonidal pit initially cannot be identified during the first drainage procedure of the abscess. Approximately 5 days later, when the edema is reduced, the pit can be identified. Often, having the patient return 5-7 days after abscess drainage to identify the pit and to excise it with a small incision is possible.

Chronic pilonidal sinus

Chronic pilonidal sinus disease is the term applied when patients who have had a pilonidal abscess drained have a pilonidal sinus. The term also refers to a pilonidal sinus that is associated with a chronic discharge without an acute abscess. The surgical options for management of a noncomplicated chronic pilonidal sinus include excision with primary closure, excision and laying open of the tract, wide and deep excision to the sacrum, incision and marsupialization, and phenol injection.

Excision of a pilonidal sinus^[7] entails excision of the midline pits and lateral openings down to the presacral fascia, with removal of minimal surrounding skin. In general, removing more than 0.5 cm of skin surrounding the sinus opening is not necessary. Curetting the wound to remove the hair, granulation tissue, and skin debris is essential to the promotion of adequate wound healing. Although performing this procedure under local anesthesia alone is possible, mild sedation in addition to local anesthesia allows for a more complete excision and a more comfortable patient.

Currently, there are surgeons modifying the technique of sinus excision with minimal tissue removal in an attempt to decrease morbidity. In addition to pit excision and curettage, these surgeons are using synthetic fibrin sealant to close these small defects.^[8] Early data have shown a reduction in the amount of time it takes for these patients to return to work. Radiofrequency ablation techniques have also been trialed, in an attempt to reduce postoperative pain.^[9] These 2 innovations reflect the ongoing attempt to define a less invasive procedure with equal efficacy.

Lord and Millar popularized their technique of coring out the midline epithelial follicles, but they also included a brush in their procedure to cleanse the cored cavity of hair and any hair left over in the remaining laterally oriented, granulation-lined tract. The brushing of the tracts continues in the outpatient setting in the postoperative period until the tract heals completely and closes. The follicle excision sites may be closed primarily but are usually packed and dressed to heal by secondary intention.

Bascom described using a lateral incision for entry into the pilonidal cavity. Curettage of the cavity is accomplished through this lateral incision, which is not excised. The midline pits are excised separately, including the epithelialized tube. The midline incisions are closed, while the lateral wound may be either left open to drain and heal by secondary intention or closed primarily. The advantages of a primary closure are small wounds; quicker healing time, usually within 3 weeks; minimal wound care; earlier return to work; and no need for daily, scheduled dressing changes. The obvious disadvantages are wound infection and wound dehiscence.

Rather than primarily closing a midline or lateral vertical incision, some physicians advocate the use of asymmetrical^[10] or oblique elliptical incisions in an attempt to keep incisions out of the natal cleft, where wound healing is poor, and to prevent unnecessary tension on the closure of the wound. The goal of the asymmetrical incision is to reduce the depth of the gluteal fold, thereby eliminating the frictional forces between the 2 opposing skin edges. Although the use of an incision that crosses the vertical gluteal fold to excise the pilonidal cavity does eliminate a vertical suture line within the gluteal fold,^[11] healing times may remain considerable.

Skin flaps have also been described to cover a sacral defect after wide excision. Similarly, this keeps the scar off the midline and flattens the natal cleft. The potential complications include loss of skin sensation in the flap, which is observed in more than 50% of patients, and necrosis of the flap edges. Again, primary healing is achieved in 90% of cases.

An option has been described in which the pilonidal sinus is excised and the tract is laid open to allow healing by secondary intention; this technique, which is intended to ensure adequate drainage for the cavity,^[12] avoids a wound infection after primary closure. In those cases in which the primary closure is not free of tension, consider laying the tract open. Even after excision of the pilonidal sinus down to healthy presacral fascia, the wound is still considered contaminated. Aerobic and anaerobic organisms are found in 50-70% of wounds. The disadvantages of laying the tract open are the inconvenience to the patient, with frequent dressing changes, and close observation of the wound to ensure proper wound healing and to avoid premature closure of the skin edges. The average time for wound healing to occur is approximately 6 weeks. Laying the tract open is always appropriate when a cellulitis is surrounding the pilonidal sinus.

Primary wound closure versus wound healing by secondary intention are the 2 principal surgical options for a chronic pilonidal sinus.^{[12, 13]} Differences remain between these 2 techniques in terms of wound healing and recurrence. Although primary closure has the potential for earlier wound healing if infection does not occur, it does require that the patient restrict many activities until wound healing is complete. The incidence rate of failed primary healing is approximately 16%. This is because a primary closure is rarely completely free of tension and the wound is considered contaminated despite excision and debridement. Recurrence rates after primary closure may be as high as 38%. Although the technique of excising the pilonidal disease and allowing the patient to heal by secondary intention requires longer healing time, it is associated with a lower rate of recurrence.

Not uncommonly, wounds may require 4-6 months to heal, but on average, the healing time is approximately 2 months. The recurrence rate ranges from 8-21%. The reduced recurrence rate is felt to be due to the more broad-based, flattened, and hairless scar produced by secondary intention.^[10] This prevents buttocks friction, hair penetration, and hair follicle infection. Although advantages exist, these open wounds require aggressive management in the form of frequent dressing changes and close observation by the patient and surgeon.

Marsupialization as a treatment option of a pilonidal sinus was first introduced in 1937. Marsupialization is a compromise between primary wound closure and wound healing by secondary intention. The rational is to avoid wound infection and dehiscence after primary closure, as well as frequent packing of the open wound. With marsupialization, the wound is sutured open. After excision of the pilonidal sinus, cavity, and lateral tracts, the cavity is scrubbed and curetted to remove hair and granulation tissue. The skin edges of the wound are then sutured to the presacral fascia. The wound is then loosely packed and requires daily dressing changes.^{[13, 14]}

Marsupialization provides the patient with a smaller wound compared with wounds that are left open to granulate. By suturing the wound open, wound infection is prevented and the subcutaneous tissue is covered, resulting in reduced healing time. Healing is usually complete by 6 weeks, and the recurrence rate has been reported to be 4-8%. Many authors consider marsupialization to be the preferred method of treatment for chronic pilonidal disease, because it avoids closure of a contaminated wound and combines shorter healing times with a lower recurrence rate. The patient still needs to pay meticulous attention to personal hygiene, with daily wound cleansing and frequent hair shaving and removal.

Complex or recurrent pilonidal disease

See Complications for information about surgical therapy for complex or recurrent pilonidal disease.

With excision of pilonidal disease and healing by secondary intention, the open wounds left after surgery require aggressive management in the form of frequent dressing changes and close observation by the patient and surgeon.

Because of the poor quality of life that results from open excision and packing in the surgical treatment of pilonidal disease, Spyridakis et al evaluated whether platelet-derived growth factors could speed the wound-healing process.^[15] Results from a controlled trial using 52 patients indicated that postoperative treatment with local infusion of growth factors hastens recovery.

Patients who received the platelet-derived growth factors went back to their normal activities approximately 17 days after surgery, when mean wound volume was about 10 cm³, while control group patients returned to normal activities around postoperative day 25. Surgical wounds in the platelet group healed completely in 24 days; wounds in the control group took more than 30 days to heal (p < 0.01). The authors concluded that platelet-derived growth factors enhance the healing process, thereby shortening patient recovery time.

For excellent patient education resources, visit eMedicine's Skin, Hair, and Nails Center. Also, see eMedicine's patient education articles Pilonidal Cyst and Abscess.

Patients with recurrent pilonidal disease or complex, unhealed pilonidal wounds present a challenge to the surgeon. Tissue loss from previous attempts at excision further complicates the surgical management and limits options. The causes of recurrence are thought to be an unrecognized sinus at the time of the initial excision; repeated infections of the scar, causing abscess; or an intergluteal cleft anatomy that promotes the accumulation of perspiration, friction, and the tendency for hair to grow into the scar. The midline scar is the most susceptible to the recurrence of pilonidal disease and poor wound healing.

The techniques developed for recurrent disease and unhealed wounds generally involve the use of a flap procedure to achieve primary closure and to obliterate the deep natal cleft. This relocates hair follicles away from the midline and prevents the frictional forces associated with the principal etiologic factors in the development of pilonidal disease. Reserve the use of a flap closure for complex or recurrent pilonidal disease that has failed to respond to the simple, conservative operative techniques that are initially used to treat chronic pilonidal disease.

A wound that has failed initial therapy must be reexcised down to the sacrococcygeal fascia. The reexcision must include the unhealed wound, scar, and granulation tissue. A flap procedure^{[16, 17, 18, 19, 20]} is then performed to achieve primary wound closure. The techniques available include (1) the cleft closure, (2) the advancement flap (Karydakis procedure^{[21, 22]} ), (3) the local advancement flap (3-plasty rhomboid flap^[16] or V-Y advancement flap), and (4) the rotational flap (gluteus maximus myocutaneous flap).

The cleft closure technique involves excising the wound using a triangular incision, with the apex of the incision lateral to the apex of the natal cleft. The inferior margin becomes crescent shaped, with its point positioned towards the anus. A skin flap involving only the dermis is created on the convex side of the lower wound margin. Prior to beginning the procedure, the line of contact of the buttocks is marked to define the lateral edge of the raised skin flap. The 2 skin edges are then overlapped, and the excess skin is excised. This creates a primary closure that is off midline and obliterates the intergluteal cleft. The wound is closed in multiple layers over a closed suction drain. The recurrence rate is reported to be 3.3%.

The advancement flap or Karydakis procedure^{[21, 22]} begins by excising the wound, with the sinuses removed en bloc with an elliptical specimen of overlying skin. The incision is made off midline. Once the wound is excised, a full-thickness flap is created on the opposite side of the semilateral incision. This allows the opposite side to be mobilized in order to allow primary wound closure, thus avoiding a midline wound. The wound is closed in multiple layers over a closed suction drain. This technique has been used as a primary procedure for the surgical management of pilonidal disease. The disadvantage is that the dissection is too extensive for an outpatient setting. The recurrence rate is reported to be 1.3%.

Local advancement flaps, such as the 3-plasty rhomboid flap or V-Y advancement flap, are methods of covering defects resulting from recurrent pilonidal disease. However, such flaps in the pilonidal area may be at risk for compromised vascularity due to continued infection, external compression, cigarette smoking, and tension on the flap. Accordingly, whenever an advancement flap is contemplated, a myocutaneous flap should be considered.

Complex wounds are reconstructed using muscle and myocutaneous flaps, because these flaps typically heal well and cover areas of extensive skin loss. Compared to skin flaps, these flaps are less susceptible to infection and have a predictable vascular supply that promotes safe elevation and better wound healing. These techniques are technically demanding and produce reliable results (with recurrence rates of 6-20%); however, they require prolonged hospitalization and longer operating time and are associated with more serious complications. A failed flap is a significant problem that ultimately leads to more extensive skin loss and a wound that is difficult to manage. These procedures are reserved for the surgical management of complex, recurrent wounds when more conservative procedures have failed.

In summary, the goal for treatment of pilonidal disease is 2-fold. The first is excising and healing with a low rate of recurrence. The second is minimizing patient inconvenience and morbidity after the surgical procedure and avoiding hospitalization with loss of workdays. The method used to treat the patient should satisfy these goals. A definite shift has occurred among physicians to treat these patients in an outpatient setting. A new class of proponents who support nonoperative management point out that regardless of the therapy used, the pilonidal disease resolves after age 40 years. These physicians focus their efforts on conservative medical management of pilonidal sinus disease rather than on a surgical cure for the disorder.