A Meta-Analysis Investigating Incisional Negative Pressure Wound Therapy for the Prevention of Surgical Site Infection

Hannah Groenen; Hasti Jalalzadeh; Stijn de Jonge; Niels Wolfhagen; Ricardo Orsini; Anne Eskes; Marja Boermeester

Prophylactic use of negative pressure wound therapy on primary closed incisional wounds (iNPWT) has increasingly been used for the prevention of postoperative wound complications, including surgical site infections (SSI). Current international guidelines for the prevention of SSI made recommendations regarding this topic. However, since publication of these guidelines, an enormous amount of new randomized controlled trials (RCTs) have been conducted, which have not been implemented in their recommendations. In this study, we have multiple aims. Primarily, we provide an overview of all available evidence and conduct an update of a previous systematic review and meta-analysis. Furthermore, we aim to explore additive value of new RCTs with a trial sequential analysis (TSA).

We hypothesize that iNPWT is an effective intervention for the prevention of SSI over a broad range of surgical procedures.

For the overview of all available evidence, we identified existing systematic reviews and meta-analyses of RCTs, including those conducted for guideline development, comparing iNPWT with standard dressings in all types of surgery. PubMed, Embase and Cochrane CENTRAL databases were searched on November 1, 2022. For the meta-analysis, we used the same literature search and screening method to identify RCTs. We calculated relative risks (RR) with corresponding 95% confidence intervals (CI) using a Mantel-Haenzsel random-effects model. TSA was used to assess the risk of random error. The certainty of evidence was evaluated using the Cochrane Risk of Bias-2 tool and GRADE approach.

In the systematic review, 58 RCTs with 13,716 patients were included. Meta-analysis showed, with high-certainty of evidence, a reduction of SSI rate with iNPWT compared to standard dressings (RR 0.67, 95% CI: 0.59-0.76). For TSA of all trials in the meta-analysis, the cumulative Z-curve crossed the trial sequential monitoring boundary for benefit. We identified eight previously published systematic reviews including meta-analyses investigating the effect of iNPWT on SSI and compared the results. 

GRADE assessment showed high-certainty evidence, through the great number of included RCTs and patients, that iNPWT is effective in reducing SSI. Compared to previous meta-analysis, the RR stabilized and the confidence interval narrowed indicating less uncertainty in the evidence. Furthermore, TSA indicated that new RCTs are unlikely to meaningfully change the effect estimate.