Double-stage venous cannulation combined with Avalon® cannula for potential prolongation of respiratory ECMO in end-stage pulmonary disease.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a treatment option to correct blood oxygenation in cases of severe respiratory failure. However, it is time-limited and, in cases of no- recovery, it is a bridge-to-lung transplant therapy. We report our experience of two patients waiting for emergency lung transplantation under VV-ECMO using the Avalon® cannula. Both presented signs of ECMO failure after prolonged support, i.e. increased hemolysis, decreased blood flow rate and increased negative pressure of the venous inflow line, leading to an inadequate systemic oxygenation. The addition of a second venous inflow line, by the insertion of another venous femoral cannula, significantly increased blood flow rate, decreasing both centrifugal pump rotation speed and negative pressure (suction) of the venous inflow line. These hemodynamic improvements, together with reduced blood consumption, were maintained during an additional week of ECMO support. Ultimately, both patients died from multi-organ failure due to the absence of available donor organs. Few cases having been described up until now, but the addition of a second venous drainage cannula to the Avalon® system could potentially improve hemodynamic parameters and, therefore, stabilize hypoxemic patients. This may be an option to gain time in long-lasting VV-ECMO support as a potential life-saving attempt