Background and Objectives: Pilonidal Sinus Disease shows an increasing incidence. Surgical interventions are often necessary; thus, we wanted to analyze whether the usage of methylene blue (MB) for staining the PSD fistulas for better visualization during surgery shows an effect concerning recurrence rates. Materials and Methods: A thorough data search and cross-study data synthesis of publications in the time period of 1833 to 2023 lead to a total of 7936 studies focusing on PSD. The data sets were scanned for the eligibility criteria, namely treatment information, follow-up, recurrence data, and the use of MB in surgery. The data were sorted into different surgical treatment groups, and the recurrence rates were analyzed using Kaplan–Meier-survival curves. Results: A total of 1192 studies involving 130,677 patients were eligible for analysis. A total of 263 studies were performed with MB (22.1%, n = 25,602 patients) and 929 studies without MB (77.9%, n = 105,075 patients). Overall, there was a highly significant difference in RR between the group of MB-stained patients and those without (p < 0.0001), even if analyzed separately for treatments. Primary open approach, primary midline closure, primary asymmetric closure, and Limberg/Dufourmentel all showed a significantly lower RR when MB was used (p < 0.0001). The use of MB in Bascom/Karydakis-Flap showed a statistically significant disadvantage concerning RR (p < 0.0001), and Other Flaps showed less RR with the use of MB (p = 0.011); both groups showed a notable loss of follow-up data, diminishing the meaning of these p values. Conclusions: This study shows that the use of MB as a staining technique in PSD surgery may be beneficial regarding recurrence rates. Therefore, the routinely use of MB staining in PSD surgery should be considered.
Maak et al. (Fri,) studied this question.