A 47-year-old transgender woman developed a persistent rectovaginal fistula following neovagina construction. Colonoscopy identified a 5-mm fistulous tract near the dentate line. Initial management included argon plasma coagulation (APC) for edge debridement followed by OTS clip closure (Padlock clip, Aponos Medical Corp, Kingstone, New Hampshire). Due to recurrence, a second session was performed with additional debridement and placement of TTS clips. Because the fistula persisted despite both OTS and TTS clip attempts, we transitioned to endoscopic vacuum therapy (EVT). A handmade negative-pressure system was assembled using an adaptively crafted catheter wrapped in polyurethane material, enabling continuous suction within the fistulous cavity. EVT sessions were repeated with interval reassessment. After two catheter-based vacuum exchanges, the cavity demonstrated marked reduction, robust granulation tissue, progressive collapse of the fistulous tract, and ultimately complete closure. This case highlights EVT as an option rescue therapy for complex rectovaginal fistulas unresponsive to conventional endoscopic closure. A tailored, multimodal endoscopic approach can achieve complete healing while avoiding the need for more invasive surgical interventions.