Pilonidal Sinus

Pilonidal Sinus

Introduction to Procedure

We know that undergoing any procedure is a scary experience.  We understand the worry and anxiousness that is associated with surgeries and procedures and aim to walk the road to recovery with you every step of the way. We put this information together using the very helpful handbook, ‘Handbook of Surgical Consent” from Rajesh Nair and David J. Holroyd.  We hope that the following information will answer all your questions and help you with the preparation phase for your procedure.

Description of procedure

A pilonidal sinus is a small tract present in or near the natal cleft at the top of the buttocks.  They commonly form around a dilated hair follicle into which hairs, desquamated skin, and other debris become entrapped leading to secondary infection (the pit is the primary cause).

There are two traditional methods for excising the pilonidal sinuses and two for closing the wound.  Regarding the excision the first is a midline approach, the second off-midline.  When closing the wound following the excision of pilonidal sinuses one method is to leave the wound open (therefore allowing healing through secondary intention), the second method is for primary closure.  Risks involved have been structured around the categories mentioned here, however, within these categories there are a number of different surgical procedures for which individual risks have not been given.

Operative techniques

Rhomboid flap:  The sinus tracts are excised and a rhomboid flap is transposed to cover the defect.

V-Y advancement flap:  In this technique a V incision is made, this is then approached to cover the defective as a Y shape.

Bascom procedure:  Lateral (or off-line) incision to access the pilonidal cavity followed by curettage.  The midline pits are then excised separately.  The midline incisions are closed, the lateral incisions are left open.

Karydakis procedure:  A midline elliptical incision of the sinus down to the sacrum.  A flap is then created by undercutting the midline side of the wound and advanced across the wound to the opposite side and sutured in place.  The skin is then closed.

Marsupialisation:  The sinus is incised; the borders are raised and stitched to form a pouch.  This gradually loses and may need to be packed until this has happened.

Additional procedures that may become necessary
  • Drainage of underlying sepsis
  • Laying open of sinus tract
  • Insertions of surgical drain
  • Diagnostic: Assess extent of injury.
  • Therapeutic: To resolve a symptomatic or recurrent pilonidal sinus.
Alternative procedures/conservative measures
  • Conservative: Meticulous hygiene although resolution of the sinus is unlikely.
Serious/frequently occurring risks
  • Bleeding, infection, pain, scar, prolonged healing, wound dehiscence, need for regular dressing changes, large cavity/dimple/scar, recurrence (open wound 53%, closed wound 8.7%).
  • Midline procedures:Surgical site infection (124%) recurrence rate (9.4%), variable healing time (midline open wound is 41-91 days, midline closed wound is 10-27 days).
  • Off-midline procedures:Surgical site infections (3.6-9.3%), recurrence rate (1.5-2.4%), variable healing time. (off-midline open wound 41-120 days, off-midline closed wound is 15-23 days).
Blood transfusion necessary
  • Group and save: The process of determining the patient’s ABO blood group and screening serum for the presence of antibodies to common red cell antigens that can cause transfusion reactions in emergency situations.
Type of anaesthesia/sedation
  • Regional.
  • Local anaesthesia.
  • General anaesthesia.
Follow-up or need for further procedure
  • Regular follow-up is required to monitor progress.

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