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 randomized controlled trial

PURPOSE: NPWT has been tried in many surgical fields, including colorectal, thoracic, vascular, and non-healing wounds, for the prevention of SSI. However, its efficacy in the prevention of SSI-grade IV closed abdominal wounds is yet to be explored. METHODS: All patients with grade IV abdominal wounds were included in the study. They were randomized into the conventional arm and the VAC arm after confirming the diagnosis intra-operatively. The sheath was closed, and the skin was laid open in the postoperative period. In the VAC arm, the NPWT dressing was applied on postoperative day (POD)-1 and removed on POD-5. In the conventional arm, only regular dressing was done postoperatively. The skin was closed with a delayed primary intention on POD-5 in both arms. The sutures were removed after 7 to 10 days of skin closure. RESULTS: The rate of SSI (10% in the VAC arm vs. 37.5% in the conventional arm, p-value = 0.004) was significantly lower in the VAC arm, as were the rates of seroma formation (2.4% in the VAC arm vs. 20% in the conventional arm, p = 0.014) and wound dehiscence (7.3% vs. 30%, p = 0.011). The conventional arm had a significant delay in skin closure beyond POD5 due to an increased rate of SSI, which also led to a prolonged hospital stay (5 days in the VAC arm vs. 6.5 days in the conventional arm, p-value = 0.005). CONCLUSION: The VAC dressing can be used routinely in grade IV closed abdominal wounds to reduce the risk of SSI and wound dehiscence.