Pilonidal Disease Treatment & Management

The ideal treatment for a pilonidal sinus varies according to the clinical presentation of the disease. First, it is important to divide pilonidal disease into the following three categories, which represent different stages of the clinical course:

• Acute pilonidal abscess
• Chronic pilonidal disease
• Complex or recurrent pilonidal disease

Surgical management is then tailored to the classification category. Although there are several treatment options for pilonidal disease in each category, they all have similar goals, as follows:

• Wound healing with a low risk of recurrence
• Short hospitalization
• Maximal patient comfort
• Low morbidity, with few wound-management problems

In addition, treatment should allow the patient to resume normal daily activities as quickly as possible.

Ideally, the method used to treat the patient should satisfy all of these goals. A definite shift has occurred among physicians toward treating these patients in an outpatient setting. Current proponents of nonoperative management point out that regardless of the therapy used, the pilonidal disease resolves after the age of 40 years. These physicians focus their efforts on conservative medical management of pilonidal disease rather than on a surgical cure for the disorder.

Concern surrounding long-term pilonidal disease is secondary to the rare occurrence of squamous cell carcinoma found in the pilonidal sinus tracts. The treatment is similar to that of other squamous cell carcinomas (ie, excision and grafting if necessary). There has been discussion about the utility of treating this disease process with chemotherapy and radiation after excision, an approach that is increasingly common with high-risk disease. ^[12]

No specific contraindications exist for the treatment of pilonidal disease. Acute infections should be drained; however, when more extensive procedures are required, every effort should be made to perform these in a noninfected field.

Practice parameters for the management of this disease have been developed by the American Society of Colon and Rectal Surgeons (ASCRS). (See Guidelines.)

There are several medical treatments for pilonidal sinuses. It is fairly widely agreed that an abscess formed from a pilonidal sinus should undergo surgical treatment with incision and drainage. However, regimens for elective treatment of pilonidal sinuses vary widely.

One of the simplest medical treatments of pilonidal sinuses is to shave the sacral area free of hair and to pluck all visible embedded hair in the sinus. ^[13] There have been several suggestions of applying laser hair removal treatments to this region to decrease the likelihood of further exacerbations. Some success has been reported, but there remains a need for forther studies to determine the utility of this treatment. ^[14]

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 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.

In Europe, it has been much more common to treat pilonidal sinuses with phenol injections ^{[15, 16, 17]} than it has been in the United States. Both chronic pilonidal disease and acute pilonidal abscess (after incision and drainage) may be managed by phenol injection.

In this procedure, 80% phenol is injected into the sinus, left there for 1 minute, and then expressed out of the cavity. The sinus is then curetted. This can be repeated as many as three times, for a total of 3 minutes of phenol exposure during a single 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 in the range of 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 follow a postoperative hair removal regimen, including shaving of the surrounding areas on a near-daily basis. Dressings are used for comfort.

Another medical therapy that can be applied after simple curettage of the sinus tract is fibrin glue. The glue is applied to each individual tract after curettage, and the excess is then wiped away. ^[18] Early data showed a reduction in time to return to work. Reports suggested that healing rates were comparable to those of the Bascom operation (see Surgical Therapy). ^[10]  

A Cochrane review from early 2017, however, found that the currently available evidence was insufficient to determine whether fibrin glue offered a significant benefit in this setting, either alone or in conjunction with surgery. ^[19]  A systematic review from 2021 found that fibrin glue seemed beneficial in the management of pilonidal disease but noted the need for further high-quality studies to confirm this potential benefit. ^[20]  

Radiofrequency ablation (RFA) techniques have also been studied in an attempt to reduce the pain associated with the procedures. ^[21]  Laser ablation of the pilonidal sinus is receiving interest as well. ^[22]

These innovations reflect the ongoing effort to define an approach to the treatment of pilonidal disease that is less invasive than standard methods but at least equally effective.

Acute 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, using local anesthesia. ^[23]

If possible, the drainage incision should be made laterally, away from the midline. Wounds heal poorly in the deep, intergluteal natal cleft, for two reasons. The first is the frictional motion of the deep cleft, which creates continuous irritation to the healing wound; the second is the midline nature of the wound, which is a product of constant lateral traction during sitting.

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 and causing further pilonidal sinuses to form.

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 that requires further treatment.

When incision and drainage of an abscess is performed for pilonidal disease, the patient should be informed that this 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, because of the acute inflammatory response surrounding the abscess. Approximately 5 days later, when the edema is reduced, the pit can be identified.

Chronic pilonidal disease

Chronic pilonidal disease is the term applied when patients have undergone at least one pilonidal abscess drainage procedure and continue to have a pilonidal sinus tract. The term also refers to a pilonidal sinus that is associated with a chronic discharge without an acute abscess. Surgical options for management of a noncomplicated chronic pilonidal sinus include the following:

• Excision and laying open of the sinus tract
• Excision with primary closure
• Wide and deep excision to the sacrum
• Incision and marsupialization
• Bascom procedure
• Asymmetrical incisions

Excision and laying open of sinus tract

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, ^[24] avoids the wound infections that can be seen after primary closure. This technique can be either the primary treatment option or a secondary option chosen with a view to wound tension. In cases where the primary closure is not free of tension, the wound can be left to heal by laying the tract open.

Even after the pilonidal sinus has been excised 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 the need for 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. Not uncommonly, wounds may require 4-6 months to heal, but the average healing time is approximately 2 months.

The recurrence rate is in the range of 8-21%. The reduced recurrence rate is believed to be due to the more broad-based, flattened, and hairless scar produced by secondary intention. ^[25] This prevents buttocks friction, hair penetration, and hair follicle infection. Although advantages exist, the disadvantages associated with these open wounds (ie, aggressive management in the form of frequent dressing changes and close observation by the patient and surgeon) must be taken into account.

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 (PDGFs) could speed the wound-healing process. ^[26] Results from a controlled trial involving 52 patients indicated that postoperative treatment with local infusion of growth factors hastens recovery.

In this study, ^[26] patients who received the PDGFs went back to their normal activities approximately 17 days after surgery, when mean wound volume was about 10 cm³, whereas 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. The authors concluded that PDGFs enhance the healing process, thereby shortening patient recovery time.

Excision with primary closure

Excision of a pilonidal sinus ^[23] entails excision of the midline pits and lateral openings down to the presacral fascia, with removal of minimal surrounding skin. In general, it is unnecessary to remove more than 0.5 cm of skin surrounding the sinus opening. Curetting the wound to remove hair, granulation tissue, and skin debris is essential for promoting adequate wound healing. Although this procedure can be performed with local anesthesia alone, the addition of mild sedation to local anesthesia allows a more complete excision and a more comfortable patient.

Primary wound closure and wound healing by secondary intention are the two principal surgical options for a chronic pilonidal sinus. ^{[24, 6]} There remain some differences between these two approaches with regard to 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 of failed primary healing is approximately 16%. This is because a primary closure is rarely completely free of tension and because 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 a longer healing time, it is associated with a lower recurrence rate.

In a study that included 242 patients with symptomatic pilonidal disease, Khodakaram et al compared conventional wide excision (n=129) with a modified Lord-Millar (mLM) approach consisting of minimal excision of pilonidal sinuses with primary suture (n=113). ^[27] The mLM operation was associated with more frequent use of local anesthesia, a lower frequency of hospital admission, fewer postoperative health care visits (2.4 vs 14.6), and a shorter average sick leave (1.0 vs 34.7 days). Estimated 5-year recurrence rates were similar (32 vs 23%). Cost per operated patient and utilization of hospital resources were also lower for the mLM group.

Incision and marsupialization

Marsupialization as a treatment option of a pilonidal sinus was first introduced in 1937. It represents a compromise between primary wound closure and wound healing by secondary intention. The aim 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. Finally, the wound is loosely packed; daily dressing changes are required. ^{[6, 28]}

Marsupialization provides the patient with a smaller wound as 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.

Bascom procedure

Bascom and Edwards described a procedure in which pilonidal disease was treated with only removal of the hair and the follicles. ^{[29, 30]} The recurrence rate in these early reports was 8%, and all of the patients healed within 3 weeks of the procedure. Since the initial reports, there have been several studies that showed comparable results. ^{[31, 32]}

The Bascom procedure focuses on avoiding the midline incision and performing a minimal amount of tissue removal. The approach is described as consisting of a lateral incision, removal of the hair, and excision of the sinus tract with small incisions overlying each sinus. The lateral incision is tunneled medially toward the base of the sinus tract, and this region can be curetted to remove the base of the sinus.

The cavity is cleansed and either closed primarily or packed open, depending on the operator's preference. The advantages of a primary closure are small wounds, a shorter healing time (usually ≤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.

Asymmetrical incisions

Rather than primarily closing a midline or lateral vertical incision, some physicians advocate the use of asymmetrical ^[25] or oblique elliptical incisions in an attempt to keep incisions out of the natal cleft. In this way, the procedure can be performed in a midline vertical orientation, with the final incision being lateral to the gluteal cleft.

This operation, often termed the Karydakis procedure, ^{[33, 34]} begins with excision of the wound and en-bloc removal of the sinuses with an elliptical specimen of overlying skin. The incision is made off the midline. Once the wound is excised, a full-thickness flap is created on the opposite side from the semilateral incision; this allows the opposite side to be mobilized for 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 surgical management or for complicated disease. The disadvantage is that the dissection is too extensive for an outpatient setting. The recurrence rate is reported to be 1.3%. 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, ^[35] 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.

Complex or recurrent pilonidal disease

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

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 include the following:

• Unrecognized sinus at the time of the initial excision
• Repeated infections of the scar, causing abscess
• 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. Flap closure should be reserved 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 not responded to initial therapy must be reexcised down to the sacrococcygeal fascia. The reexcision must include the unhealed wound, scar, and granulation tissue. A flap procedure ^{[36, 37, 38, 39, 40]} is then performed to achieve primary wound closure. The techniques available include the following:

• Cleft closure
• Advancement flap (Karydakis procedure ^{[33, 34]} )
• Local advancement flap (3-plasty rhomboid flap ^[36] or V-Y advancement flap)
• Rotational flap (gluteus maximus myocutaneous flap)

The cleft closure technique involves excising the wound with 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.

Before the procedure is begun, the line of contact of the buttocks is marked to define the lateral edge of the raised skin flap. The two skin edges are then overlapped, and the excess skin is excised. This creates a primary closure that is off the 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 ^{[33, 34]} (described earlier) can be used as a primary procedure or for the treatment of recurrent complicated disease.

Local advancement flaps (eg, the 3-plasty rhomboid flap and the V-Y advancement flap) are used to cover defects resulting from recurrent pilonidal disease. However, such flaps in the pilonidal area may be at risk for compromised vascularity as a consequence of 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 by using muscle and myocutaneous flaps because these flaps typically heal well and cover areas of extensive skin loss. Compared with skin flaps, they are less susceptible to infection and have a predictable vascular supply that promotes safe elevation and better wound healing.

Reconstructions using muscle and myocutaneous flaps are technically demanding, usually requiring the assistance of a plastic surgeon; however, they produce reliable results (with recurrence rates of 6-20%). Among the disadvantages of such procedures is that they necessitate prolonged hospitalization, require longer operating times, and are associated with more serious complications.

A failed flap represents a significant morbidity that ultimately leads to more extensive skin loss and a wound that is difficult to manage. These procedures are reserved for surgical management of complex recurrent wounds when more conservative procedures have failed.

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, cleansing, hair removal, and close observation by the patient and surgeon.