Trans-aortic or pulmonary artery drainage for left ventricular unloading and veno-arterial extracorporeal life support: a porcine cardiogenic shock model.

The peripheral veno-arterial extracorporeal life support (V-A ECLS) in cardiogenic shock (CS) may lead to LV overload. The trans-aortic suction device (Impella, ABIOMED Inc., Danvers, Massachusets) was compared to the pulmonary artery (PA) drainage, for LV unloading efficacy during V-A ECLS in a porcine cardiogenic shock model. A dedicated CS model included twelve swine (21± 1.8-weeks old and weighing 54.3 ± 4.6 kg) supported with V-A ECLS and randomized to Impella or PA-related LV drainage. LV unloading and end-organ perfusion were evaluated through the pulmonary artery catheter and LV pressure/volume analysis. The LV end diastolic volume sharply dropped with Impella (143.6±67.4 vs 123±75.7 ml) compared to a slight decrease in the PA cannula group (134.1±39.9 vs 130.1±34.7 ml), resulting in an overall stroke work (SW) and Pressure-Volume Area (PVA) reductions with both techniques. However, SW reduction was more significant in the Impella group (V-A ECLS 3998.8±2027.6 vs V-A ECLS + Impella 1796.9±1033.9 mmHg x ml, p=0.016), leading to a more consistent PVA reduction (Impella reduction 34.7% vs PA cannula reduction 9.7%) In terms of end organ perfusion, central and mixed O2 saturation improved with V-A ECLS, and subsequently, remaining unchanged with either Impella or PA cannula as unloading strategy (SVmO2: Impella 86.0±5.8 vs 87.8±5.8; PA cannula 82.5±10.7 vs 82.5±11.3 %). Trans-aortic suction and PA drainage provided effective LV unloading during V-A ECLS while maintaining adequate end-organ perfusion. Impella provides a greater LV unloading effect and reduces more effectively the total LV stroke work.