Differential Oxygenation During Peripheral Thoracoabdominal Normothermic Regional Perfusion in Controlled Donation After Circulatory Death: An Underrecognized Cause of Potential Allograft Dysfunction and Discard.

Abstract

Thoracoabdominal normothermic regional perfusion (TA-NRP) is increasingly adopted for cardiac allograft procurement in controlled donation after circulatory death (cDCD). In settings where ante-mortem femoral guidewire placement is permitted, peripheral TA-NRP may be employed following declaration of death to enable rapid restoration of organ perfusion, reducing warm ischemic time and avoiding manipulation of the cardiac structures before procurement. However, the differential oxygenation that may develop in this setting can be dangerously unrecognized due to supra-aortic vessel occlusion and the resulting inability to monitor upper-body oxygenation as an estimation of blood oxygenation in the ascending aorta. This phenomenon may lead to impaired myocardial oxygenation, potentially resulting in primary graft dysfunction after transplantation or, alternatively, in the unnecessary discard of an otherwise suitable cardiac allograft. In order to detect and correct this phenomenon, we implemented a modification of the TA-NRP circuit by incorporating a continuous aortic root oxygenation monitoring device. Continuous monitoring proved crucial in two scenarios: first, by identifying differential oxygenation resolved by left ventricular unloading; and second, by detecting severe aortic root desaturation after TA-NRP discontinuation, undetectable by conventional upper-body oxygenation monitoring. This simple strategy may improve the safety and reliability of donor heart functional assessment during TA-NRP.