Hydromechanical Debridement with Use of Negative Pressure Wound Therapy and Instillation to Assist Limb Salvage

Introduction: Tissue necrosis and infection stall wound healing and can lead to other complications, including disseminated infection and ampu- tation.1 For wound care patients at risk of lower limb amputation, rapid conversion from infected nonhealing wounds to healing wounds is essen- tial in avoiding amputation. Use of negative pressure wound therapy with instillation and dwelling (NPWTi-d) of a topical wound solution assists in diluting, solubilizing and removing nonviable tissue in infected wounds,2,3 which may help reverse a negative wound healing trajectory. We report our experience with NPWTi-d to adjunctively manage infected lower extremity ulcers of diabetic patients admitted under a limb salvage protocol. Methods: NPWTi-d was applied with hypochlorous acid via a retic- ulated open-cell foam dressing with through holes (ROCF-CC) in 9 complex lower extremity ulcers of 3 patients. Systemic antibiotics were administered, and sharp surgical debridement was performed prior to or in conjunction with NPWTi-d application. In addition to NPWTi-d, limb salvage protocol included diabetic control, offloading, revascularization, nutritional support and smoking cessation. NPWTi-d settings included instilling hypochlorous acid every 2 to 3.5 hours with a 10-20 minute dwell time between cycles of continuous negative pressure at -125 mmHg. At each dressing change, non-contact real-time fluorescence wound imaging was used to determine the presence and location of pathogenic bacteria, and non-contact near infrared spectroscopy studies were per- formed to measure deoxyhemoglobin, oxyhemoglobin, and ratio of tissue oxygenation (StO2). Dressings were changed 3 times/week. NPWTi-d was discontinued when patient was discharged and/or wound bed was covered with clean granulation tissue. Results: At presentation, wound size volume ranged from 4.6 to 49.2 cm3 and percent surface area coverage of nonviable tissue was between 15% and 100%. Wounds were converted to at least 90% coverage with clean granulating tissue in an average of 24.1 days during use of NPWTi-d. Amputation was avoided in all cases. Discussion: Limbs previously at risk of amputation were salvaged fol- lowing adjunctive use of NPWTi-d. NPWTi-d facilitated hydromechanical debridement as evidenced by removal of devitalized tissue through the ROCF-CC dressing. A clean granulating wound base allowed for success- ful application of cellular, acellular or matrix-like products.