Background: Cardiac transplantation is limited to an ischemic time of around 6 hours by available preservation solution and technique. Complex organ preservation devices have been developed that extend this time to 24 hours or more, but are clinically impractical. This study evaluates a portable oxygen-driven organ perfusion device weighing approximately 13.5 kg.
Methods: Organs are perfused with the University of Wisconsin solution at low perfusion pressure using less than 400 L of oxygen per 12 hours. Left ventricular parameters were measured in anesthetized adult beagles to establish control values (n = 5). Hearts were procured after cardioplegia with 4 degrees C University of Wisconsin solution, weighed, then stored for 12 hours in University of Wisconsin solution at 4 degrees C. Hearts were perfused (n = 3) or nonperfused (n = 2) during storage. Organ temperature, partial pressure of oxygen in the aorta and right atrium, perfusion pressure, and aortic flow were recorded hourly in perfused hearts. After 12 hours, hearts were transplanted into littermates and left ventricular parameters measured after stabilization off bypass.
Results: Organ weight for both groups was unchanged. Nonperfused hearts required both pump and pharmacologic support with significantly depressed left ventricular function. Perfused hearts needed minimal pharmacologic support, with left ventricular end-diastolic pressure, cardiac output, and rate of change of left ventricular pressure showing no statistical difference from control.
Conclusions: These findings confirm the potential for extended metabolic support for ischemia-intolerant organs in a small, lightweight, easily portable preservation system.