Novel surgical procedure in design of advancement endorectal flap in the surgical treatment of complex anal fistulas.

INTRODUCTION: Anal fistula is a common disease with incidence of 5.6 per 100,000 women and 12.3 men. It is most often of cryptoglandular origin. The aim of this study is to evaluate our experience with patients treated for complex anal fistula with our own complex surgical procedure with advancement endorectal flap.

METHODS: 524 patients with complex anal fistulas who were sent to our surgical clinic from January 2005 to the end of December 2022 were in- cluded in the study. We established the diagnosis by detecting the fistula tract by physical examination, anoscopy, probing the fistula tract and endorectal ultrasonography. We performed a complex operation together with the construction of the advancement endorectal flap in our own modification for all patients.

RESULTS: Primary surgical intervention in a group of 326 patients with complex anal fistulas (excluding patients with Crohn's disease) was successful in 283 (87%) patients. We identified advancement endorectal flap defect in the postoperative period in 17 (5.2%) patients, soiling in 16 (4.9%) and flatus incontinence in 9 (2.7%) patients. In a group of 120 patients after multiple surgeries (excluding patients with Crohn's disease), our surgical procedure was successful in 92 (76.6%) patients. In the postoperative period, we identified a advancement endorectal flap defect in 6 (5%) patients, soiling in 8 (6.6%) and flatus incontinence in 3 (2.5%) patients.

CONCLUSIONS: The construction of the advacement endorectal flap was curative and without affecting the level of anal continence in 87% of patients after primary surgical intervention and in 76.6% after multiple surgical procedures. Complex surgery with the construction of the advancement endorectal flap according to our procedure preserves the function of the sphincters and has a relatively low percentage of recurrences. The number of previous surgical interventions had no affect on the level of anal continence.