Cavoatrial Partial Heart Transplant: Ex Vivo Feasibility of a Novel Fontan Conduit

The Fontan circulation is the single common pathway for patients with single ventricle defects, but has adverse effects due to passive pulmonary blood flow. Pulsatile pulmonary blood flow may mitigate the adverse effects of Fontan circulation, but a subpulmonary assist device is yet to reach clinical use. We hypothesize that fresh right atrial homograft (cavoatrial partial heart transplant [CAPHT]) may be utilized as a pulsatile Fontan conduit with growth potential.

The surgical technique for CAPHT conduit procurement was demonstrated in a live porcine donor. The CAPHT conduit was connected to a cardiopulmonary bypass circuit utilizing different cannulation orientations for inflow and outflow. Electrical activity and transduced pressure were recorded.

Freshly procured live porcine CAPHT conduits demonstrate pulsatility with extracorporeal perfusion. The conduits have a variable intrinsic rhythm but have the ability to be paced epicardially. With adequate volume loading, the average generated pulse pressure was 9.2 mm Hg. The CAPHT conduit maintains viability and pulsatility for at least 152 minutes while connected to extracorporeal perfusion.

Our preliminary investigations demonstrate the technique for CAPHT conduit procurement. We show that the right atrium and vena cava can maintain viability pulsatility independent of coronary blood flow in an ex vivo setting. Subsequent in vivo studies will aim to evaluate the viability, function, and feasibility of the CAPHT conduit as an alternative extracardiac Fontan conduit that can be used as a subpulmonary assist device with growth potential.