Comparison of surgical site infection (SSI) between Negative Pressure Wound Therapy (NPWT) assisted delayed primary closure and conventional delayed primary closure in grossly contaminated emergency abdominal surgeries: a randomised controlled trial

Purpose NPWT has been tried in many surgical fields including colorectal, thoracic and vascular, and non-healing wounds for prevention of SSI. But its efficacy on prevention of SSI grade IV closed abdominal wound yet to be explored. Methods All patients with grade-IV abdominal wound were included in the study. They were randomised into conventional arm and VAC arm after confirming the diagnosis intra-operatively. The sheath was closed and skin laid open in post-operative period. In VAC arm, the NPWT dressing applied on post-operative day (POD)-1 and it was removed on POD-5. In conventional arm, only regular dressing was done postoperatively. The skin was closed with delayed primary intention on POD-5 in both the arms. The sutures were removed after 7 to 10 days of skin closure. Results The rate of SSI (10% in VAC arm vs 37.5% in conventional arm, p-value = 0.004) was significantly lower in VAC arm, as well as the rate of seroma formation (2.4% in VAC arm vs 20% in conventional arm, p = 0.014) and wound dehiscence (7.3% vs 30%, p = 0.011). The conventional arm had significantly delay in skin closure beyond POD5 due to increased rate of SSI and also lead to prolonged hospital stay (5days in VAC arm vs 6.5days in conventional arm, p-value = 0.005). Conclusion The VAC dressing can be used routinely in grade IV closed abdominal wounds to prevent SSI and other post-operative wound related complications.