Predictors of vacuum-assisted closure failure of sternotomy wounds

SummaryPurposeVacuum-assisted closure (VAC) is a minimally invasive alternative to a muscle flap for closure of sternotomy wounds. The purpose of this study is to evaluate clinical predictors of VAC therapy failure in order to predict which patients would benefit from this approach.MethodsA retrospective cohort study of all patients with VAC management of sternotomy wounds between January 1997 and July 2003 was conducted. In this study, 37 patients had VAC management of their wounds post-cardiac surgery. Prior to data collection, 12 risk factors for impaired wound healing were identified. Information was obtained from patient charts and laboratory values.ResultsEight of the 36 patients failed the VAC therapy. Of the 12 variables studied, three were found to be predictive of VAC outcome. Bacteraemic patients had a higher failure rate as compared to patients with negative blood cultures (p ≤ 0.01). Patients with wound depth ≥4 cm also had a greater occurrence of VAC failure (p ≤ 0.01). Finally, VAC failure was significantly higher in patients who had a high degree of bony exposure and sternal instability (BESI, p ≤ 0.03). Patient characteristics and co-morbidities traditionally associated with impaired wound healing did not appear to worsen outcome with VAC.ConclusionPatients who have positive blood cultures, wound depth ≥4 cm or a high degree of BESI tend to have worse outcomes with VAC and may be better managed by a surgical approach. Otherwise, VAC may be a reasonable option even in patients with high risks of impaired wound healing. Prospective randomised studies are needed to validate these hypotheses.