CONTINUOUS PERFUSION IMPROVES PRESERVATION OF DONOR RAT HEARTS - IMPORTANCE OF THE IMPLANTATION PHASE

Background. Continuous hypothermic perfusion of donor hearts may provi de extra protection for long ischemic times and suboptimal donors. The aim of three separate studies was to assess the effect of continuous hypothermic perfusion during simulated donor heart storage and implant ation. Methods. In study 1 twelve isolated rat hearts underwent 10 min utes of normothermic ischemia to simulate the effect of brain death on the heart and 5 hours of cardioplegic arrest, using University of Wis consin solution. Six hearts were statically stored in University of Wi sconsin solution at 2 degrees C, and six were perfused with University of Wisconsin solution. To assess the effect of simulated implantation , in study 2 an additional 12 hearts were statically stored for 5.5 ho urs in University of Wisconsin solution, six of which were rewarmed to a mean of 16 degrees C over the last 30 minutes of arrest. To assess the effect of simulated perfusion, in study 3 during implantation 12 h earts were rewarmed to a mean of 16 degrees C over the last 30 minutes of arrest, during which time six were perfused with 2 degrees C solut ion. Results. Hearts perfused during storage demonstrated greater reco very of prearrest power, 85.8% +/- 1.8%, than hearts preserved by stat ic storage, 72.7% +/- 3.0% (p < 0.01). The simulated warm implantation period reduced recovery of power from 68.3% +/- 5.1% to 40.2% +/- 2.0 % (p < 0.001). Perfusion during warm implantation improved recovery to 61.8% +/- 3.9% (p < 0.01). In all experiments improved function was a ccompanied by improved metabolic energy status. Conclusions. During th e implantation period of heart transplantation the donor heart sustain s injury that could amount to 50% of total ischemic injury. Continuous perfusion during the cold storage phase and during simulated implanta tion improves recovery of the donor heart. (C) 1998 by The Society of Thoracic Surgeons.