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bioRxiv · 10.1101/2022.12.12.519951

Switching the left and the right hearts: A novel bi-ventricle mechanical support strategy with spared native single-ventricle

Sisli, E.·Pekkan, K.·Yildirim, C.·Aka, I. B.·Tuncer, O. N.·Atay, Y.·Ozbaran, M.
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Abstract

Mechanical circulatory support (MCS) is used as a bridge-to-heart transplantation for end-stage failing Fontan patients with single-ventricle (SV) circulation. Donor shortage and complexity of the single-ventricle circulation physiology demands novel circulatory support systems and alternative solutions. An out-of-the-box circulation concept in which the left and right ventricles are switched with each other inspired a novel bi-ventricle MCS configuration for the "failing" Fontan patients. In the proposed configuration, the systemic circulation is maintained by a conventional mechanical ventricle assist device while the venous circulation is delegated to the native SV. This approach spares the SV and puts it to a new use at the right-side providing the most needed venous flow pulsatility. To analyze its feasibility and performance, 8 realistic Fontan circulation scenarios have been studied via a multi-compartmental lumped parameter cardiovascular model (LPM). Model is developed specifically for simulating the SV circulation and validated against pulsatile mock-up flow loop measurements for the ideal (Fontan), failed (VD) and assisted Fontan (PVR-cmcs) scenarios. The proposed surgical configuration maintained the cardiac index (3-3.5 l/min/m2) providing a normal mean systemic arterial pressure. For a failed SV with low ejection fraction (EF=26%), representing a typical systemic failure, proposed configuration introduced a venous/pulmonary pulsatility of [~]28 mmHg and a drop of 2 mmHg in central venous pressure (CVP) with acceptable pulmonary artery pressures (17.5 mmHg). In the pulmonary vascular resistance (PVR) failure model, it provided approximately 5 mmHg drop in CVP with venous/pulmonary pulsatility reaching [~]22 mmHg. For high PVR failure case with a healthy SV (EF = 44%) pulmonary hypertension is likely to occur, indicating a need for precise functional assessment of the failed-ventricle before it is considered for the proposed arrangement. Comprehensive in vitro and in silico results encourage this concept as an economical alternative to the conventional bi-ventricle MCS pending animal experiments.

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Sisli, E., Pekkan, K., Yildirim, C., Aka, I. B., Tuncer, O. N., Atay, Y., Ozbaran, M.. 2022-12-14. Switching the left and the right hearts: A novel bi-ventricle mechanical support strategy with spared native single-ventricle. https://doi.org/10.1101/2022.12.12.519951

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