Background: The relationship between venous congestion and acute kidney injury (AKI) in cardiac surgery after cardiopulmonary bypass has not thoroughly investigated. Vacuum-assisted venous drainage (VAVD) reduces venous congestion, so we hypothesized that it would reduce the incidence of AKI in cardiovascular surgery.Methods and Results: We used a retrospective propensity score-matched analysis to evaluate the effect of VAVD on AKI in adult patients undergoing cardiac surgery. The primary outcomes were AKI and renal replacement therapy (RRT). Multivariable logistic regression was used to explore the association between VAVD exposure and adverse kidney outcomes. Of 15,387 eligible subjects, 13,480 and 1,907 had gravity drainage (GD) or VAVD, respectively, during cardiopulmonary bypass. On the basis of propensity scores, there were 1,468 matched patient pairs for GD and VAVD. The average central venous pressure (CVP) in the GD group was higher than in the VAVD group (4.43±1.23 mmHg vs. 2.30±0.98 mmHg, P<0.001). The occurrence of AKI and RRT was statistically significantly different in the 2 groups [(600/1,468, 40.87%) vs. (445/1,468, 30.31%), P<0.001; (36/1,468, 2.45% vs. 8/1,468; 0.54%), P<0.001, respectively)]. Multivariate logistic regression analysis revealed that VAVD was effective in protecting kidney function.
Conclusions: VAVD was associated with a lower CVP and lower incidence of AKI, suggesting it protects adult cardiac patients from adverse renal outcomes.
Keywords: Acute kidney injury; Cardiopulmonary bypass; Cardiovascular surgery; Vacuum-assisted venous drainage; Venous congestion.