Accelerated Preoperative Wound Bed Preparation Using Negative Pressure Wound Therapy With Instillation and Dwell Time: A Comparison With Conventional Negative Pressure Wound Therapy in Necrotic Wounds

Negative pressure wound therapy with instillation and dwell time (NPWTi-d) and conventional NPWT are established treatments for complex wounds, yet direct comparative evidence remains limited. This retrospective observational study evaluated the clinical effectiveness of NPWTi-d for hard-to-heal necrotic wounds using standardized parameters from our previous research. We included 116 patients (50 NPWTi-d; 66 conventional NPWT). The primary endpoint was the time from therapy initiation to achieving a 'reference wound' suitable for definitive closure, defined in accordance with clinical trial guidance from the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). The NPWTi-d group achieved reference wound status in a median of 14 days versus 22 days for the conventional NPWT group-a statistically significant 8-day reduction. Furthermore, whereas conventional NPWT typically requires a prolonged debridement phase prior to application, NPWTi-d can be initiated earlier, even in the presence of residual necrotic tissue. Ultimately, NPWTi-d provides a synergistic clinical advantage by both shortening active treatment duration and bypassing pre-initiation delays, enabling clinicians to achieve surgical readiness significantly faster than with standard modalities.