Negative pressure wound therapy for surgical site infections: a systematic review and meta-analysis of randomized controlled trials.

Objectives: Previous studies showed the effectiveness of negative pressure wound therapy (NPWT) in preventing surgical site infections (SSIs), but current guidelines do not recommend its routine use for surgical wounds. The aim was to compare the effectiveness and safety of NPWT with standard surgical dressing or conventional therapy for preventing SSIs.

Methods: Pubmed, Embase and the Cochrane Library were systematically searched on 10 April 2019. Also, we searched clinicaltrials.gov and references of relevant studies. Eligibility criteria were randomized controlled trials (RCTs) and adult surgical patients were included. The effectiveness of NPWT versus standard surgical dressing or conventional therapy was investigated. Relative risks (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were used to estimate the pooled effect of dichotomous outcomes and continuous outcomes respectively. The primary outcome was surgical site infections. The quality of included studies and the certainty of the evidence were assessed using the risk of bias tool and the GRADE approach.

Results: A total of 45 RCTs with 6624 surgical patients were included. NPWT reduced SSIs (RR 0.58; 95% CI 0.49-0.69) and wound dehiscence(17 RCTs; RR 0.80; 95% CI 0.65-1.00). NPWT did not increase the risk of hematoma (9 RCTs; RR 0.91; 95% CI 0.40-2.07) and hospital readmission(9 RCTs; RR 0.77; 95% CI 0.52-1.12) or prolong length of hospital stay(15 RCTs; MD -0.38; 95% CI, -0.78 to 0.02). NPWT significantly increased the risk of all adverse event-related outcomes (10 RCTs; RR 3.21; 95% CI, 1.17-8.78). The level of certainty was identified as low for the primary outcome and very low for all the secondary outcomes.

Conclusions: Compared with standard wound care, NPWT may reduce the risk of SSIs. We are uncertain whether NPWT reduces or increases the risk of wound dehiscence, haematoma, hospital readmission and all adverse event-related outcomes or if it shortens or prolongs length of hospital stay.