PTU-168 Risk factors for transperineal gracilis flap interposition failure: another reason to avoid mesh

Abstract

Introduction Transperineal gracilis muscle flap interposition (TGMFI) has been used to treat complex or recurrent perineal fistulas including rectovaginal fistula (RVF), pouch vaginal fistula (PVF), rectourethral fistula (RUF), and complex perianal fistula, refractory to heal or having failed other procedures (CPF), with an overall success rate of 50–90%. Our study was designed to evaluate risk factors for TGMFI failure in the treatment of complex perineal fistula. Method After IRB approval, a retrospective review of all patients who underwent TGMFI interposition for complex perineal fistula between 1994–2014 was undertaken. Data collected included patient demographics including BMI, fistula characteristics, prior attempts at fistula repair, procedure details including suture material, use of mesh, and surgical outcomes. The results were compared between patients whose fistula healed and those whose fistula failed to heal. Risks factors for TGMFI failure were assessed using Student’s t-test and Fisher’s exact test. Results 84 patients [34 females; mean age 57.5 (22–85) yeas] with a mean follow up of 18 (1–120) months were included. The most common cause of fistula was radiation. All patients had a diverting stoma. 36 (42.8%) patients (RVF: 9, RUF: 23, PVF: 2, CPF: 2) healed after initial TGMFI; 24 (28.6%) healed following further procedures including 10 redo TGMFI, for a final success rate of 71.4%. 24 (28.6%) patients (RVF: 11, PVF: 2, RUF: 10 RUF, CPF: 1) failed. The only significant risk factors for TGMFI failure were female gender (44.1% vs. 20% p = 0.04), 2 or more surgical attempts at prior fistula repair TGMFI (42.8% vs 20.4%; p = 0.04), urethral closure using mesh vs no mesh (80% vs. 25%; p = 0.01), and perineal skin closure with nylon versus polyglactin suture material (56.2% vs. 27.8%; p = 0.03). Conclusion Risks factors for TGMFI failure in patients with complex fistula include female gender, 2 or more prior surgical closure attempts, use of nylon suture material for perineal closure, and mesh interposition for urethral closure. Disclosure of interest None Declared.