Pilonidal cyst derives its name from Latin pilus (hair) and nidus (nest). O.H. Mayo was the first to describe the disease in 1883.


  • Pilonidal cyst
  • Infected pilonidal cyst or sinus should undergo I&D followed by later excision

Preoperative Considerations

  • Dye (e.g., methylene blue) may be injected for better identification of complicated sinuses. It must be done several days before surgery to avoid excessive staining of the operative area.

Relevant Information

  • Hair punctures the skin and becomes embedded
  • Risk factors: male sex, family history, overweight/obese, trauma, irritation, sedentary lifestyle, hirsute habitus, poor hygiene

Surgical Technique

  • Patient is placed in the prone position with hips elevated and the table broken in the middle. Strips of tape are anchored symmetrically about 10 cm from midline at the level of the sinus and pulled down and fastened beneath the table in order to spread the intergluteal fold for better visualization. The area is prepped and draped in the usual sterile fashion.
  • An ovoid incision is made around the opening of the sinus tract off-midline about 1 cm from either side. 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. The subcutaneous tissue is excised downward and laterally to the fascia underneath. Care is taken to protect this fascia because it is the only defense against the spread of deeper infection. Small, pointed hemostats should be used to clamp bleeding vessels so the smallest amount of tissue reaction occurs. Electrocoagulation may be used to control bleeding and keep the amount of buried suture material to a minimum. Some surgeons prefer to avoid burying any suture by using compression or electrocoagulation to control all bleeding. Extreme care should be taken in the dissection of the lower end of the incision because many small, troublesome vessels encountered tend to retract when they are divided. 
  • Careful inspection of the wound is done to make sure all sinus tracts have been removed. The subcutaneous fat is undercut at its junction with the underlying fascia –  this undercutting should extend only far enough to allow approximation of the edges without tension.
  • The wound is washed with saline and dried completely. If an unexpected infection has been encountered, the wound should be packed and left open. In uncomplicated sinuses, the wound is closed. The closure should be off-midline. Dead space should be eliminated by a series of interrupted vertical mattress sutures. The suture is introduced 1 cm or little more than the margins of the wound to include full thickness of the mobilized flap of skin and subcutaneous tissue. A second bite includes the fascia at the bottom of the wound. Suture is then continued deep into the opposite flap, then directed back to the original side as it passes back through the skin margins. Once tied, this obliterates the dead space and accurately approximates the skin margins. Sutures should be placed at intervals no more than 1 cm. Skin approximation must be performed since even a small amount of overlap can slow healing. A pressure dressing is applied and sutures remain in place for 10 – 14 days.
  • Exteriorization. When the sinus appears small and in the presence of recurrence, a probe can be inserted into the sinus and the skin and subcutaneous tissue divided. The entire sinus and any tributaries must be laid wide open and all granulation tissue must be removed. 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 minimum drainage. The raw margins of the wound are held apart by a gauze pack until healing is complete. 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 is enhanced.

Postoperative Considerations

  • Early ambulation is advisable
  • Patient should sit on a cushion or on one buttock or the other to avoid sitting on the incision.
  • Wound dressings should be changed frequently and repeatedly replaced