Clinical efficacy and failure-related factors of the loose-seton procedure combined with transanal opening of the intersphincteric space technique (LoSet-TROPlS) in the treatment of complex anal fistulas

OBJECTIVE: To observe the clinical efficacy of the loose-seton procedure combined with transanal opening of the intersphincteric space technique (LoSet-TROPlS) for complex anal fistulas. METHODS: A retrospective analysis was conducted on the clinical data of 73 patients with cryptoglandular anal fistulas who underwent LoSet-TROPlS in our hospital from September 2020 to March 2021. The study evaluated the surgical healing rate, recurrence rate, time to seton removal, and postoperative anal incontinence. RESULTS: The median follow-up time was 34.0 (32.0, 38.0) months. The primary healing rate was 83.56% (61/73), with a failure rate of 16.44% (12/73). The recurrence rate was 9.84% (6/61), and the overall healing rate was 86.30% (63/73). The median time for seton removal was 27 (23, 30) days. No patients experienced formed stool incontinence. Two patients occasionally had anal gas or fluid leakage, which improved after biofeedback therapy. Two patients experienced occasional mucous discharge. There was no statistically significant difference in anal canal and rectal pressure before and after surgery (P > 0.05). CONCLUSIONS: The LoSet-TROPlS is an effective treatment for complex anal fistulas while preserving anal function. The procedure is not complicated and can be promoted for clinical application.