ASSESSMENT OF FUNCTION, PERFUSION, METABOLISM, AND HISTOLOGY IN HEARTS PRESERVED WITH UNIVERSITY-OF-WISCONSIN SOLUTION

Background. University of Wisconsin solution has shown promise for prolonged cardiac preservation. This study compared the effects of 24-hour cold storage and perfusion preservation techniques by assessment of function, perfusion, metabolism, and histological changes. Methods and Results. Three groups of rabbit hearts (n=6 each) were evaluated: 1) control with immediate reperfusion, 2) continuous perfusion preservation, and 3) cold storage. Hearts were reperfused for 30 minutes, and left ventricular systolic pressure (LVSP) was measured by isovolumetric balloon (LVEDP, 20 mm Hg). We used Tl-201 to assess perfusion and C-14-acetate to assess metabolism by macroautoradiography. LVSP was similar for controls and hearts preserved with continuous perfusion (134.8+/-2.1 versus 112.2+/-6.0 mm Hg, respectively). Hearts preserved with cold storage techniques were significantly worse (36.7+/-6.0 versus 134.4+/-8.2 mm Hg, p<0.001). Controls showed homogeneous perfusion and metabolism, whereas hearts in the continuous perfusion group showed mild hypoperfusion and histological damage (26.4+/-2.7% of left ventricular cross section). Hearts in the cold storage group had 51.7+/-1.2% of the left ventricle hypoperfused and damaged. Histology in the control group was normal; in the perfused group, there were only mild changes; and in the cold storage group, there were extensive derangements of cellular architecture. Conclusions. Continuous perfusion of the heart with 4-degrees-C modified University of Wisconsin solution provided function comparable to that of control. Conversely, cold storage showed extremely poor return of function. Autoradiography confirmed mild perfusion and metabolism abnormalities in control and continuous perfusion hearts, whereas there was marked derangement of cellular architecture, perfusion, and metabolism in the cold storage hearts.