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Peripheral veno-arterial extracorporeal membrane oxygenation (ECMO) is a powerful life-saving tool; however, it can sometimes induce severe pulmonary edema in patients with critical heart failure. We report favorable outcomes in critically ill patients by using a central ECMO system with an innovative blood perfusion method.

We analyzed 10 patients with severe heart failure and pulmonary edema who were treated with the central ECMO system at our institution between April 2022 and October 2023. The system consists of central cannulation with two inflows from the right atrium and left ventricle, and two outflows to the aorta and pulmonary artery, connected by two Y-connectors to a single ECMO circuit (RALV-AOPA ECMO). In this system, blood flow to the pulmonary artery is adjusted and mean pulmonary artery pressure is limited to <20 mm Hg, which reduces right ventricular afterload and prevents the worsening of pulmonary edema and hemorrhage.

Six patients were diagnosed with fulminant lymphocytic myocarditis, and four were diagnosed with coronavirus disease 2019-related myocardial injury. The ejection fraction was 6.5 ± 4.1%. The average intraoperative pulmonary vascular resistance was 4.6 ± 1.3 Wood units. After 24 h, the mean pulmonary arterial pressure was 12.8 ± 4.3 mm Hg, and pulmonary vascular resistance was 1.5 ± 0.3 Wood units. The duration of central RALV-AOPA ECMO was 3.7 ± 2.1 days. Finally, six patients were weaned, three received HeartMate3, and one received heart transplantation. At follow-up, all patients remained alive (428 ± 208 days), and two patients experienced cerebrovascular accidents without any lasting sequelae.

The central RALV-AOPA ECMO is an innovative system that achieves early improvement in pulmonary vascular resistance and is safe and feasible for patients with acute biventricular failure and pulmonary edema.

The cost and complexity associated with animal testing are significantly reduced by using mock circulatory loops prior. Novel mock circulatory loops allow us to test biomedical devices preclinically due to their flexibility, scalability, and cost-effectiveness. The presented work describes the development of a hardware-in-the-loop platform to emulate human physiology for the Istanbul Heart (iHeart-II) LVAD.

A closed-loop system is developed whereby the effect of the LVAD on the heart and vice versa can be studied. An acausal model of the cardiovascular system is calibrated to emulate advanced-stage heart failure. A new prototype of the iHeart-II LVAD is connected between two air-actuated chambers emulating the left ventricle and aortic chambers with PID controllers tracking numerically modeled pressures from the in silico model. A lead-lag compensator is used to maintain fluid level. Controllers are tuned using nonlinear Hammerstein-Weiner models identified using open-loop data. The iHeart-II LVAD is operated at various speeds in its operational range, and the resulting hemodynamics are visualized in real time.

Hemodynamic variables, such as LVAD flow rate, aortic, left ventricular, and pulse pressure, demonstrate trends similar to clinical observations. The iHeart-II LVAD achieves hemodynamic normalization at ~3500 rpm for the emulated condition.

A novel evaluation methodology is adopted to study the performance of the iHeart LVAD under advanced-stage heart failure emulation. The models and controllers used in the platform are readily replicable to facilitate VAD research, pedagogy, design, and development.