P150 Treatment protocols for laser hair removal in pilonidal sinus disease: a post hoc analysis of a retrospective cohort study

Abstract Pilonidal sinus disease (PSD) is a chronic, debilitating condition predominantly affecting young men. Laser hair depilation is an established adjunct to surgical treatment for PSD and can lead to reduced rates of recurrence and postsurgical interventions. This post hoc analysis of a retrospective cohort study evaluates 97 patients referred for laser hair removal (LHR) at a regional centre between 2017 and 2023. Patient demographics, PSD clinical stage, laser type, number of laser sessions, presence of surgical intervention and type of surgical procedure performed, and treatment outcomes were extracted from consecutive electronic medical records. Statistics were performed using Microsoft Excel and R. Treatment outcomes were categorized as improvement (healed, improved) or no improvement of underlying PSD. Disease severity was classified using the method of Guner et al. (Guner A, Cekic AB, Boz A et al. A proposed staging system for chronic symptomatic pilonidal sinus disease and results in patients treated with stage-based approach. BMC Surg 2016; 16: 18). The median number of LHR sessions was 8 (interquartile range 5.5–10), with treatment cessation occurring at visual assessment of 70% hair reduction. The number of LHR sessions provided was the only predictive factor for symptom resolution (Kruskal–Wallis test, P < 0.001). Data were also transformed into a binary logistic regression model for treatment response (likelihood ratio test, P < 0.001). There was no statistically significant association between treatment outcome and age, type of laser, disease severity, presence of surgical intervention, or type of surgical procedure performed. No complications were reported and there was only one case of PSD recurrence. Furthermore, no statistically significant correlation was found between increasing disease severity and the number of treatment sessions required (P = 0.51), though a weak positive correlation was noted (Spearman’s rank = 0.07, visual inspection of estimated marginal means). These findings support the theory that LHR removes the irritating hairs in the natal cleft in the early stages of PSD, allowing the sinuses, pits and inflammation associated with PSD to resolve. The authors propose that complete hair removal, rather than the current treatment threshold of 70%, may optimize treatment outcomes. This study highlights the critical role of the number of laser hair removal sessions in achieving PSD improvement and resolution, while surgical interventions appear less predictive of treatment outcomes. In the current literature, surgical treatment appears associated with a higher risk of disease recurrence and morbidity burden, although literature on laser hair depilation alone for early-stage pilonidal sinus disease are sparse. Future protocols may benefit from emphasizing a higher number of laser treatment sessions and complete LHR to improve treatment success rates. Future work could aim for a cost-effectiveness analysis comparing LHR against current surgical management, and exploratory studies to better establish treatment protocols for LHR in this patient population.