TROPIS Procedure in Complex Anal Fistulas: Single-Center Long-Term Results

Transanal opening of the intersphincteric space (TROPIS) has recently emerged as a sphincter-preserving option for the treatment of complex anal fistulas. Although high success rates have been reported in large international series, data on long-term real-world outcomes remain limited. This study aimed to evaluate long-term results of TROPIS, focusing on recurrence and continence, and to compare them with existing literature.

This retrospective single-center cohort included 28 patients who underwent the TROPIS procedure between 2020 and 2023. Demographic data, Parks classification of fistula, operative details, recurrence rates, healing times, and continence outcomes were analyzed. Recurrence was defined as the reappearance of fistula after initial complete healing. Continence was assessed using the Wexner score. Patients were followed with a mean follow-up of 680 ± 120 days.

The mean age was 42.6 years. According to Parks' classification, 21 patients (75%) had transsphincteric, 5 (17.9%) extrasphincteric, and 2 (7.1%) complex transsphincteric (horseshoe variant). The average healing time was 36 days. No recurrence occurred within the first 90 days; thereafter, 9 patients (32.1%) developed recurrence (median 225 days, range 90-660). Early postoperative mild incontinence occurred in 42.9% of patients, but only 5 (17.8%) reported persistent mild symptoms at long-term follow-up. No major incontinence was recorded.

TROPIS appears to be a safe, sphincter-preserving technique for complex anal fistulas, providing acceptable healing with preserved continence. However, recurrence rates in this cohort were higher than those reported internationally, underscoring the need for careful patient selection, surgical expertise, and adequate long-term follow-up.