Minimally Invasive Phenol Treatment for Pilonidal Sinus: A Single-Center Case Series From Japan

Pilonidal sinus is a chronic inflammatory condition of the natal cleft that commonly affects young adults. Conventional surgical treatments, such as wide excision and flap reconstruction, are associated with large wounds and prolonged recovery. Phenol treatment has been reported as a minimally invasive alternative in several countries; however, clinical experience in Japan remains limited. We retrospectively reviewed patients with pilonidal sinus who underwent phenol treatment at our institution between 2020 and 2025. After excision of the midline pits and curettage of the sinus tract, undiluted phenol was injected into the cavity and subsequently neutralized with ethanol. Clinical data, including patient characteristics, number of pits, operative time, postoperative hospital stay, complications, and recurrence, were analyzed. A total of 11 patients were included in the study. The median age was 27 years (range, 13-50), and 10 patients were male. The median number of pits was 3 (range, 1-5). The median operative time was 32 min (range, 19-56), and the median postoperative hospital stay was 2 days (range, 1-6). Postoperative bleeding occurred in two patients and was successfully managed conservatively. No recurrence was observed during the follow-up period (median, 331 days; range, 100-979). Phenol treatment for pilonidal sinus appears to be a simple and minimally invasive procedure associated with short hospitalization and favorable short-term outcomes. This technique may represent a useful treatment option for pilonidal sinus in Japan.