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.