A pilonidal sinus is a small infected tract or a network of interlinking tracts under the skin between the buttocks. The exact cause is unknown but it may be from loose hairs pushing into the skin, combined with friction from clothes. The risk of developing a pilonidal sinus is increased by spending long periods of time sitting down, being overweight, a persistent irritation or injury to the affected area, having a hairy buttock cleft or a family history of the condition.
A pilonidal sinus does not usually cause symptoms unless it is infected and an abscess develops causing pain, redness, swelling under the skin and leakage of blood and pus.
Treatments include conservative management with regular bathing and keeping the area dry, and antibiotics if the sinus is infected. However this does not close the sinus tract. Procedures to close the sinus include injecting fibrin glue and surgical excision.
Endoscopic ablation of a pilonidal sinus is less invasive than surgery and is usually done as a day case, using spinal or local anaesthesia. With the patient in the prone position, the external opening of the sinus is incised and a fistuloscope is inserted into the sinus tract. A continuous jet of irrigation solution is used, allowing optimal visualisation and assessment of the inside of the sinus. Under direct vision, forceps are used to remove hairs, infected tissue and any debris. Then an electrode is passed through the fistuloscope to cauterise the main sinus tract and any secondary tracts or abscess cavities. Necrotic material is removed using an endobrush and the sinus tract is cleaned using irrigation solution.