Distinct recurrence patterns according to disease manifestation in pilonidal sinus disease treated with cleft lift surgery at 5 years' follow-up in a large prospective Danish cohort.

Aim: Pilonidal sinus disease (PSD) is a common condition particularly affecting the young population. The disease is incompletely understood, and optimal treatment is still debated. However, off-midline closure techniques have become the standard of care in more advanced cases. The literature is, however, lacking disease stratification in evaluation of surgical results. The aim of this study was to evaluate the surgical outcomes in a prospective cohort following Bascom's cleft lift (BCL) in primary extensive disease, nonhealing wounds after previous surgery and recurrence on a large Danish cohort from a high-volume centre.

Method: The study is based on a prospective database established at Randers Regional Hospital in 2016. All patients undergoing BCL surgery from June 2016 until June 2020 were included in this study.

Results: Three hundred and ninety two patients (326 men/66 women) underwent BCL surgery over a 4-year period. Of these, 127 (32.4%) presented with primary extensive PSD, 136 (34.7%) with nonhealing wounds and 129 (33.9%) with recurrent PSD. Overall, 87% healed uneventfully within the first 3 months, and 17% had recurrence at a median follow-up of 60 months (45-73 months). However, the risk of recurrence was higher among patients with nonhealing wounds (20%) and recurrence (17%) compared with primary extensive manifestation (13%).

Conclusion: Treatment of advanced PSD remains challenging with a high rate of wound complications and recurrences, stressing the need for dedicated care. Patients with either failed surgery or recurrence need particular attention.