Transaortic Catheter Venting for Left Ventricular Unloading in Veno-Arterial Extracorporeal Life Support: A Porcine...

Background and Objectives: Left ventricle (LV) overloading during veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) is detrimental to myocardial recovery. To determine whether LV unloading using transaortic catheter venting (TACV) is effective, we analyzed the effect of TACV in a human-sized porcine model. Materials and Methods: Hypoxic biventricular dysfunction was induced in 11 pigs using femoro-femoral VA-ECMO and custom-made TACV catheters in the LV through the common carotid artery. Hemodynamic conditions were then simulated. The TACV was either opened or closed under a controlled ECMO flow. Conversely, the ECMO flow was adjusted, varying from 1 L to 4 L, with and without TACV; 2115 observations were collected. Results: In comparing observations without TACV (TACV-) and with TACV (TACV+), the change in left ventricular end-diastolic pressure (LVEDP) after TACV application was -1.2 mmHg (p < 0.001). In the linear regression model, the reduction in LVEDP was maximized when the baseline LVEDP and ECMO flow were higher. When escalating the ECMO flow in the respective settings of TACV- and TACV+, the rise in LVEDP was significantly lower in TACV+. Conclusions: TACV decreased LVEDP; this effect was more prominent when ECMO flow and baseline LVEDP were higher. These findings suggest that TACV might support LV recovery through effective unloading, even when ECMO flow is high.