Postobstetric Anovaginal Fistula Managed by Primary Repair and Modified Martius Flap with Intraoperative Indocyanine Green Fluorescence Imaging

A BSTRACT Anovaginal fistula (AVF) is a debilitating complication of obstetric trauma causing fecal incontinence and severe social morbidity. This report describes a 31-year-old primipara who developed an AVF after obstructed labor complicated by right vaginal wall hematoma. Magnetic resonance imaging fistulogram demonstrated a curvilinear tract extending from the right lateral anal canal to the upper vagina with secondary ramifications. The patient underwent primary fistula excision and layered reconstruction with tissue interposition using a modified Martius labial fat pad flap. Intraoperative vascularization assessment was performed using indocyanine green (ICG) fluorescence to confirm real-time flap perfusion and viability. The ICG imaging demonstrated uniform and homogeneous fluorescent signals throughout the flap, indicating excellent arterial inflow and venous drainage. The postoperative course was uncomplicated with early restoration of continence and good wound healing at follow-up. This case highlights the value of ICG angiography as an objective, real-time assessment tool for vascularized tissue interposition and supports the modified Martius flap as an effective sphincter-preserving option for postobstetric AVF repair combined with modern perfusion accessing technology.