12-HOUR CANINE HEART PRESERVATION WITH A SIMPLE, PORTABLE HYPOTHERMICORGAN PERFUSION DEVICE

Background. Cardiac transplantation is limited to an ischemic time of around 6 hours by available preservation solution and technique. Compl ex organ preservation devices have been developed that extend this tim e to 24 hours or more, but are clinically impractical. This study eval uates a portable oxygen-driven organ perfusion device weighing approxi mately 13.5 kg. Methods. Organs are perfused with the University of Wi sconsin solution at low perfusion pressure using less than 400 L of ox ygen per 12 hours. Left ventricular parameters were measured in anesth etized adult beagles to establish control values (n = 5). Hearts were procured after cardioplegia with 4 degrees C University of Wisconsin s olution, 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 i n the aorta and right atrium, perfusion pressure, and aortic flow were recorded hourly in perfused hearts. After 12 hours, hearts were trans planted into littermates and left ventricular parameters measured afte r stabilization off bypass. Results. Organ weight for both groups was unchanged. Nonperfused hearts required both pump and pharmacologic sup port 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 ventri cular pressure showing no statistical difference from control. Conclus ions. These findings confirm the potential for extended metabolic supp ort for ischemia-intolerant organs in a small, lightweight easily port able preservation system.