Management of mini-cardiopulmonary bypass devices: Is it worth the energy?

Purpose of review To address the role of mini-cardiopulmonary bypass systems in cardiac operations, with specific respect to clinical outcome. Recent findings Mini-cardiopulmonary bypass systems are not accompanied by major complications, even if some safety concerns have been raised. Randomized controlled trials and large retrospective trials suggest that they can induce a beneficial effect in terms of morbidity reduction, shortening of mechanical ventilation time, ICU, and hospital stay, whereas mortality seems not to be affected. Studies failing to demonstrate significant differences were generally underpowered. A meta-analysis focused on allogeneic blood products transfusion rate demonstrates that mini-cardiopulmonary bypass systems reduce the transfusion rate (odds ratio 0.4, 95% confidence interval 0.26-0.63, P<0.001). This may be because of containment in hemodilution during cardiopulmonary bypass. The better outcome may be related to both this mechanism and the consequent reduction in transfusional needs. Summary Mini-cardiopulmonary bypass systems reduce the need for allogeneic blood transfusions. Other improvements in postoperative outcome are more debated. They require a long learning curve and are more expensive. A cost analysis based on a large randomized controlled trial is still needed to clarify the potential future role of these systems in clinical practice.