In Vitro Tests of Antegrade Distal Limb Perfusion Modalities in Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation.

Distal limb ischemia is a frequent complication of femoro-femoral veno-arterial extracorporeal membrane oxygenation (V-A ECMO) associated with high morbidity and mortality. The optimal distal limb perfusion strategies remain a challenge. Furthermore, during a prolonged weaning phase, a significant distal limb hypoperfusion due to the reduced ECMO-based flow may occur. This study evaluated the hemodynamics of different distal perfusion cannula (DPC) configurations (6Fr, 8Fr, or 10Fr introducer sheaths, 8Fr and 9Fr arterial pediatric cannulas [APC], and a 19Fr bidirectional cannula incorporating a perfusion port) through an in vitro V-A ECMO model. A simulated ECMO weaning trial was tested with gradually reduced ECMO flows and related distal perfusion. Four flow conditions were tested: continuous or pulsatile V-A ECMO flow with different simulated native cardiac output, and V-A weaning conditions. Key metrics included distal pressure, distal flow, and flow/resistance ratio. Reinforced APCs achieved the highest distal perfusion pressure and flow at the high ECMO flow, whereas the bidirectional cannula ensured consistent perfusion with low hydraulic resistance, outperforming both introducer sheaths and APCs, especially under reduced ECMO flows. Overall, the bidirectional cannula showed the most favorable hemodynamic performance across all ECMO flow conditions, followed by the APCs and the introducer sheaths.