Perioperative management - Excision of pilonidal sinus with secondary healing

• Chronic pilonidal sinus 
• Pilonidal sinus with acute abscess

• Asymptomatic pilonidal sinus without signs of inflammation does not require treatment. The patient should be informed that it may progress to a chronic or acute infection with abscess formation. Follow-up of these patients reveals that over time they are not truly asymptomatic but simply suffer from very few symptoms and will have to undergo surgery sooner or later.
• Radical excision in the abscess stage is uncertain and is associated with a high recurrence rate (up to 41%), as this is often carried out as an emergency and then by an inexperienced surgeon. In addition, complete excision of the wound will often be unnecessarily extensive because of the swelling. Therefore, the first step should be to unroof the abscess to ensure effective drainage. This is followed by radical excision during the infect-free stage 7-10 days later.

If pilonidal sinus is suspected, first note risk factors such as excessive body hair, copious sweating, obesity, and poor personal hygiene. Differential diagnosis then must first establish whether there is:

• A porus without inflammation
• Sinus with acute abscess formation
• Sinus with chronic secretion

Ultrasound, CT or MRI are not required.

In porus without inflammation, inform the patient about the course of the disease, in particular about the fact that spontaneous healing is not possible, and that malignant transformation may be possible in very rare cases (see above). Schedule the patient for annual follow-ups.

In case of acute abscess, the typical signs of a soft tissue abscess with local redness, warmth and swelling paramedian to the gluteal fold are usually present. Pilonidal sinus with acute abscess requires immediate treatment, and the first step should be surgical abscess drainage (1-2 cm long incision). The wound should be drained adequately, and definitive surgical treatment usually takes place seven to ten days later.

• Recurrence
• Local wound healing problems
• Bleeding
• Unsightly cosmesis in the gluteal region
• Impaired skin sensitivity
• Longer healing period of possibly several months