Determination of Optimal Coronary Flow for the Preservation of "Donation After Circulatory Death" Heart

Introduction: Transplantation of hearts from donation after circulatory death donors (DCD) have the potential to increase the number of transplants. However, DCD hearts undergo an extended period of warm ischemia and necessitate use of ex-vivo machine perfusion preservation after recovery. The minimum flow needed to meet basal oxygen demand (DCRIT) and the necessary machine perfusion conditions to achieve this are unknown for perfused DCD hearts. Aim: To determine the DCRIT of DCD hearts during midthermic perfusion preservation. Methods: Sprague Dawley adult male rats were anesthetized, intubated, heparinized (500 U/rat) and paralyzed with vecuronium (2 mg/rat). The DCD protocol was observed by withdrawal of ventilatory support. After circulatory death, 30 min of “stand-off” time was observed. DBD rats were continuously ventilated. Hearts (DBD n=8, DCD n=4) were perfused on Langendorff mode, with an oxygenated preservation solution at 15oC starting at a flow index of 300 mL/min*100g, decreasing it by 40 m...