Surgery · Medical Literature
Effectiveness of negative pressure wound therapy versus conventional dressings in emergency laparotomy: a systematic review and meta-analysis of randomized controlled trials.
Abstract
Surgical site infections represent a significant complication after emergency laparotomy, contributing to increased morbidity, mortality, and healthcare costs. Negative pressure wound therapy (NPWT) may reduce the incidence of surgical site infections; however, evidence from randomized controlled trials remains inconsistent. To present a systematic review and meta-analysis, comparing NPWT with conventional dressings in emergency laparotomies. Systematic searches were conducted according to the Cochrane Handbook and reported according to the PRISMA 2020 guidelines. The PubMed, Embase, and Cochrane CENTRAL databases were searched since their inception, using terms related to emergency laparotomy, NPWT, and conventional dressings. The reference lists of included studies were manually examined to identify additional eligible trials. Only randomized controlled trials that compared NPWT with conventional dressings in emergency abdominal surgeries and that reported surgical site infection rates or other clinical outcomes were included. The primary outcome was the incidence of surgical site infection. Secondary outcomes included wound dehiscence, seroma formation, length of hospital stay, and 30-day mortality. Eight randomized controlled trials, totaling 1,377 patients (707 in the NPWT group and 670 in the conventional dressing group), were included. NPWT significantly reduced the risk of surgical site infection (risk ratio [RR] 0.43; 95% confidence interval [CI] 0.26-0.73; p=0.002; heterogeneity [I2]=76%) and wound dehiscence (RR 0.32; 95%CI 0.18-0.58; p=0.0002). No significant differences were observed regarding seroma formation (RR 0.59; 95%CI 0.34-1.01; p=0.05), length of hospital stay (mean difference [MD] -0.39 days; 95%CI -1.15- 0.36; p=0.92) or mortality (RR 0.96; 95%CI 0.55-1.68; p=0.88). This systematic review and meta-analysis of randomized clinical trials suggests that NPWT reduces the incidence of surgical site infection and wound dehiscence after emergency laparotomy, supporting its use in high-risk patients. Surgical site infections are a major postoperative complication after emergency laparotomies, contributing substantially to morbidity, mortality, and healthcare costs. Strategies to reduce postoperative complications have increasingly focused on perioperative optimization through evidence-based, multimodal protocols. Retrospective analyses have demonstrated the efficacy of intermittent negative pressure wound therapy in diminishing the incidence of surgical site infections following laparotomy in patients undergoing gynecological and general surgical procedures. Nonetheless, the findings derived from randomized controlled trials have yielded inconsistent results. This original systematic review and meta-analysis of randomized controlled trials demonstrated the efficacy of negative pressure wound therapy in reducing the incidence of surgical site infections and wound dehiscence among patients undergoing emergency laparotomy when compared to conventional dressings.
Clinical relevance
Surgical site infections (SSIs) are a leading source of postoperative morbidity, mortality, and excess healthcare costs following emergency laparotomy — a population at inherently elevated wound complication risk due to contaminated fields, physiologic derangement, and limited preoperative optimization. Prior randomized controlled trial (RCT) data on negative pressure wound therapy (NPWT) in this setting have been inconsistent, leaving surgeons without high-confidence guidance on wound closure strategy. This systematic review and meta-analysis of 8 RCTs (n=1,377) provides the most rigorous current synthesis of evidence to inform intraoperative and perioperative decision-making for emergency abdominal surgery.
Key findings
1. NPWT significantly reduced the risk of surgical site infection compared to conventional dressings (RR 0.43; 95% CI 0.26–0.73; p=0.002), representing a 57% relative risk reduction in SSI incidence, though notable heterogeneity was present (I²=76%). 2. NPWT significantly reduced the risk of wound dehiscence (RR 0.32; 95% CI 0.18–0.58; p=0.0002), representing a 68% relative risk reduction — the most robust finding in the analysis. 3. Seroma formation did not differ significantly between NPWT and conventional dressings (RR 0.59; 95% CI 0.34–1.01; p=0.05), narrowly missing conventional thresholds for statistical significance. 4. Length of hospital stay showed no statistically significant difference between groups (mean difference −0.39 days; 95% CI −1.15 to 0.36; p=0.92). 5. Thirty-day mortality was not significantly different between NPWT and conventional dressing groups (RR 0.96; 95% CI 0.55–1.68; p=0.88). 6. The meta-analysis included 8 RCTs totaling 1,377 patients (707 NPWT vs. 670 conventional dressing), conducted via systematic searches of PubMed, Embase, and Cochrane CENTRAL per Cochrane Handbook and PRISMA 2020 methodology; NNT was not explicitly reported in the abstract.
Practice implications
Surgeons performing emergency laparotomy — particularly in contaminated or dirty wound classifications where SSI risk is highest — should consider prophylactic NPWT over conventional dressings for primary wound closure, given a 57% relative reduction in SSI and 68% relative reduction in wound dehiscence. Patient selection should prioritize those at elevated wound complication risk (e.g., obesity, diabetes, immunosuppression, fecal contamination, or hemodynamic instability at time of surgery), as these are the populations most likely to derive meaningful absolute risk reduction. The absence of significant benefit in hospital length of stay or 30-day mortality suggests NPWT's value is localized to wound-level outcomes, and cost-effectiveness analyses should guide institutional protocol adoption; the high heterogeneity in SSI outcomes (I²=76%) warrants cautious, individualized application pending further standardized RCT data.