Vacuum-assisted venous drainage (VAVD) has been proposed as a better alternative option than conventional gravitational venous drainage (GVD) in cardiac surgery. However, the literature reports conflicting results between both methods in terms of post-cardiac surgery complications. Therefore, we aimed to perform a meta-analysis to compare clinical outcomes between VAVD and GVD in patients undergoing cardiac surgery.

PubMed, Scopus, and Web of Science databases were searched for any randomized control trials or cohort studies that compared clinical outcomes between VAVD and GVD in patients undergoing cardiac surgery.

Sixteen studies with 8426 patients were included in our study. The pooled effect estimate of the postoperative results showed a statistically significant association between VAVD and decreased blood loss/chest tube drainage (MD = −88.7, 95% CI = −154.71 to −22.69, p-value = 0.008), amount of packed red blood cells (pRBC) transfusion (MD = −0.25, 95% CI = −0.27 to −0.22, p < 0.00,001), re-exploration (RR = 0.6, 95% CI = 0.35 to 1, p = 0.05), and re-operation (RR = 0.47, 95% CI = 0.23 to 0.99, p-value = 0.05). However, our study revealed no significant difference between both groups in terms of postoperative mortality, hospital/ICU stay, other blood product transfusions, change of free hemoglobin at 24 h, and other clinical outcomes.

Our study revealed that VAVD is at least equivalent and may provide some benefits compared to GVD in patients undergoing cardiac surgery. While, VAVD requires specific expertise and training in order to optimize its outcomes, its ability to reduce blood loss and blood transfusion, support its use as a valuable alternative for GVD in high-risk groups.