Veno-venous versus Veno-arterial extracorporeal membrane oxygenation for the management of primary graft dysfunction following lung transplantation: A systematic review and meta-analysis.

Background: Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. In its severe forms, extracorporeal membrane oxygenation (ECMO) may be required. However, there is no consensus on whether venovenous (VV) or venoarterial (VA) ECMO modality provides superior outcomes. The objective of this meta-analysis is to compare the use of VV-ECMO versus VA-ECMO in the management of grade 3 PGD after lung transplantation. Methods: Three databases were assessed. Primary outcome was overall survival (OS). Secondary outcomes included cerebrovascular complications, incidence of pneumonia, reintubation, acute kidney injury, ICU length of stay and ECMO duration. Hazard ratios (HR), odds ratios (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated. Reconstruction of time-to-event data and sensitivity analyses were performed for the primary endpoint. Results: Four studies including 210 patients (VV-ECMO: 142; VA-ECMO: 68) were analyzed. VV-ECMO was associated with improved early survival (HR 0.41; 95%CI 0.22 to 0.76; p=0.005) within the first 2 months after transplantation, although no significant difference was observed in long-term survival (HR 0.72; 95%CI 0.46 to 1.15; p=0.168). Cerebrovascular complications occurred significantly more often in the VA-ECMO group (OR 18.33; 95%CI 3.62 to 92.81; p=0.0004), while no significant differences were found in pneumonia, reintubation, acute renal failure, ICU length of stay, or ECMO duration. Conclusion: VV-ECMO appears to be associated with better short-term survival and fewer neurological complications compared to VA-ECMO in patients with grade 3 PGD after lung transplantation.