Long-term outcomes and predictors of recurrence after sinus laser-assisted closure (SiLaC) for pilonidal sinus disease: a retrospective study of 509 patients

This study aimed to evaluate the long-term efficacy of sinus laser-assisted closure (SiLaC) for pilonidal sinus disease (PSD) through a large-sample, single-center retrospective study and to analyze the factors influencing healing and recurrence. Consecutive patients with PSD who underwent SiLaC between March 2019 and February 2025 were retrospectively enrolled. Demographic data, clinical characteristics, surgical parameters, and follow-up outcomes were recorded. A total of 509 patients were included, comprising 425 males and 84 females, with 65 patients aged ≤ 18 years. The median follow-up duration was 29 (10, 47) months. The overall healing rate was 98.6% (502/509), and 22 of 502 patients who achieved complete wound healing developed recurrence (4.4%). The only postoperative complication observed was minor wound bleeding, occurring in 2.8% (14/509) of patients, and no postoperative infections were observed. Only 2.9% (15/509) of patients required analgesics. The median patient satisfaction score was 9 (9, 10), the median time to return to work was 7 (5, 13) days, and the median healing time was 37 (32, 42) days. Exploratory multivariable logistic regression suggested an association between age ≤ 18 years and non-healing at 2 months (OR = 5.527, 95% CI: 1.166–26.188, P = 0.031). Among patients who achieved complete wound healing, multivariable Cox proportional hazards regression showed that each one-year increase in age was associated with a lower hazard of recurrence (HR = 0.83, 95% CI: 0.74–0.93, P < 0.001). Longer disease duration was also associated with a modestly increased hazard of recurrence (HR = 1.01, 95% CI: 1.01–1.03, P = 0.034). SiLaC is a safe and effective surgical treatment for PSD, offering high healing rates, low recurrence rates, and minimal complications. Younger age was associated with less favorable postoperative outcomes, including non-healing at 2 months and a higher hazard of recurrence. The association with non-healing should be interpreted cautiously because only seven events occurred. Further research is needed to explore the associations between hormonal levels and the mechanisms underlying healing and recurrence risk.