Midline pits (Photograph courtesy of Charles O. Finne MD, Minneapolis)
Pilonidal sinus (Photograph courtesy of Charles O. Finne MD, Minneapolis)
Chronic pilonidal wound (Photograph courtesy of Charles O. Finne MD, Minneapolis)
Controlling hair growth in the sinuses is important in preventing disease progression in early pilonidal disease and preventing recurrences as hair growth in the natal cleft has been linked to pilonidal disease . Hair growth can be controlled by shaving, waxing, electrolysis, and use of depilatory creams . Another technique for hair removal is laser depilation. Khan et al. had good results in preventing disease recurrence using this technique. Photoelectrolysis has the advantage of being able to reach deep areas not easily accessed by other techniques of hair removal . The complications of laser depilation include skin erythema and irritation, hyperpigmentation or hypopigmentation, and skin crusting . The paper emphasized the adherence to hair removal techniques and suggested that lapse in adherence as the cause in disease recurrence.
Phenol injection into pits has been suggested. The mechanism of action is thought to be due to destruction of the epithelium in the pit, leading to inflammation and scar formation . The procedure is performed under local anesthesia on an outpatient basis. Weekly phenol instillation in addition to local hair removal has a success rate of approximately 60%  with recurrence rate of approximately 11% . High recurrence rate is a disadvantage of phenol injection, and is thought to be due to inadequate phenol penetration of extensive sinus tracts . The complications of this therapy are local toxicity, resulting in skin irritation, burns, cellulitis, and abscess formation . This is avoided by protecting the surrounding skin and with the application of ointment containing nitrofurantoin prior to phenol application which can reduce the risk of skin burns [6, 16]. Analgesia, topical anesthetics use, and wound care can aid in skin healing if phenol toxicity occurs (Figs. 6.4, 6.5, 6.6, and 6.7).
Connection between pilonidal sinus tracts delineated following peroxide injection
Unroofing of pilonidal disease (Photograph courtesy of Charles O. Finne MD, Minneapolis)
Marsulpialzation following unroofing (Photograph courtesy of Charles O. Finne MD, Minneapolis)
Antibiotic use has a limited role in conservative management of pilonidal disease. The use of preoperative antibiotics has not shown benefit in wound healing, preventing complications, or disease recurrence . Equivocal data exists for the use of antibiotics postoperatively [2, 16]. In chronic pilonidal disease, antibiotic use is only recommended in cases of associated cellulitis, immunosuppression, and systemic illness .
Surgical approaches are offered when there is failure of conservative management and in cases of chronic pilonidal disease [1, 15]. There are several approaches ranging from minimally invasive procedures, such as pit picking and more extensive procedures such as wide local excision.
In the acute stage incision and drainage vs needle aspiration followed by antibiotic course is recommended for acute pilonidal abscesses . Incision and drainage results in complete wound healing in 60% of cases . Definitive surgical excision is recommended after inflammation subsides, to address the resultant wound. Disease recurrence occurs in 10–15% of cases despite complete wound healing, as drainage of a pilonidal abscess does not address the underlying cause of its pathology .
Pit picking is one of the minimally invasive procedures. There are various methods of performing this type of surgery. A common feature in all these methods is the excision and removal of midline pits followed by drainage or curetting of the subcutaneous tissues. The aim of these techniques is to remove minimal amount of tissues. It is important to note that the sinus tract is not excised with these techniques. The advantage of this method is that it is performed on an outpatient basis, has short wound healing time and short recovery time. The disadvantage is a recurrence rate of approximately 20–25% in 5 year follow-up .
Sinusectomy first described by Soll et al. is another minimally invasive technique. The sinus tracts are probed and injected with methylene blue. The sinus tracts are then excised following the methylene blue delineation. The wounds are left open to close by secondary intent . A recurrence rate of 5% was reported in the study . This technique is recommended for patients with less than three pilonidal pits .
Unroofing and marsupialization (UM) of the sinus tracts is another surgical option . In this procedure no healthy, normal tissue is removed and only affected tissue is incised . This technique still results in a 1–2 cm open wound, but the wound is much smaller than the wound caused by wide local excision (WLE) . Rouch et al. described a low recurrence rate with UM when compared to WLE in their retrospective review .
The most common procedure offered is wide local excision with or without closure [1, 2, 12, 14, 17]. In this procedure all of the involved tissue is excised and the resultant wound is either closed or left to close by secondary intent . The technical approach of WLE is similar to sinusectomy and UM, in that the sinus tracts are probed and sometimes injected with methylene blue prior to being excised; however, the extent of excision is larger . The disadvantage of allowing the wound to close by secondary intention is prolonged wound healing time, increased recurrence rate, patient effort in wound care and time off work [2, 14].
Midline and off midline closure is used in primary closure following WLE. Shorter time of wound healing is noted with primary closure. Off midline closure is shown to have faster healing rates, lower infection as well as lower recurrence rates compared to midline closure . Three off midline procedures commonly used are the Karydakis flap, the Limberg flap and the cleft lift procedure (Bascom II). The advantage of off midline closure is that it first removes the chronically diseased tissue and second it flattens the natal cleft, thereby minimizing recurrence due to anatomic and mechanical stress . Disadvantage of the off midline closure is tension on the suture line, resulting in wound dehiscence, and esthetic of ultimate scar . The most common complications following off midline flap closure is hematoma, seroma and wound separation [5, 11]. The use of drains intra-operatively may prevent the formation of seromas and hematomas. If wound hematoma or seroma develop, fluid aspiration with large bore needle is suggested. Wound separation is treated with wet to dry dressing applied to the region (Table 6.1).
Flap closure techniques following WLE and their complications
Asymmetrical excision of pilonidal sinus and lateral closure of flap secured to sacrococcygeal fascia
Wound separation and delayed wound healing
Rhomboid excision of pilonidal tissue using closure with a rotational fasciocutaneous flap
Surgical site infections and wound separation
Cleft lift procedure
Excision of midline pits with mobilization of healthy skin adjacent to the midline. Skin and subcutaneous tissue is apposed for off midline closure
Seroma, hematoma and wound separation
Pilonidal disease can recur up to 20 years after surgery, but 60% will recur within 5 years . Early recurrence in midline closures is thought to be secondary to the surgical site infection and occur in up to 24% of case that undergo WLE with primary closure [2, 3]. The administration of systemic antibiotics has been reviewed in several randomized controlled trials, showing no significant benefit [2, 14, 15]. Postoperative antibiotics can be used as an adjunct following surgical excision; however studies have shown mixed results in term of wound healing and recurrence rate . Nyugen et al. suggested the use of gentamycin collagen sponge to reduce the local infection rates; however, the study did not reach statistical significance . Other studies failed to show that the use of gentamycin improved wound healing and prevented disease recurrence [2, 15].