Can leucocyte depletion reduce reperfusion injury following cardiopulmonary bypass?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was 'Can leucocyte depletion (LD) reduce reperfusion injury following cardiopulmonary bypass?'. Altogether more than 74 papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that there appears to be little or no clinical benefit gained from the use of LD treatment. The majority of studies, looking at outcomes including the duration of hospital and intensive care unit (ICU) stay, intubation time, inotropic support required and postoperative arrhythmias, found the results comparable between patients receiving LD treatment and controls. Biochemical parameters of reperfusion inflammation and cardiac damage are reduced in many studies, suggesting an attenuation of reperfusion injury at a cellular level, but this does not appear to be transferable to clinical improvement. However, one study using patients with severely low left ventricular ejection fractions (LVEF), found those receiving LD treatment required less inotropic support and experienced a significant increase in LVEF postoperatively when compared with controls, indicating that the benefit of LD may depend on preoperative status and susceptibility to reperfusion damage. In conclusion, LD should not be used routinely in cardiac surgery.