COMPARISON OF CONTINUOUS MICROPERFUSION AND COLD-STORAGE FOR PIG-HEART PRESERVATION

The aim of this study was to compare two methods of hypothermic heart preservation. Isolated hearts of pigs were preserved in cold cardiople gic solution (St. Thomas Hospital solution) either by simple storage o r continuous microperfusion (with a new perfusion device) for 6 hours (group I, n = 12), 12 hours (group II, n = 12) and 24 hours (group III , n = 12). After storage, the myocardial function was studied for 60 m inutes under nonworking conditions with an ex vivo functional testing system. Hearts preserved 24 hours by cold storage (group III) showed v entricular compliance and mean spontaneous left ventricular developed pressure significantly lower than hearts preserved by microperfusion ( respectively, 63 +/- 47 versus 14 +/- 18 mm Hg and 16.8 +/- 22.0 versu s 83 +/- 33 mm Hg). After 12 hours (group II) of preservation, mean le ft ventricular developed pressure was higher in microperfused hearts c ompared to immersed hearts (respectively, 133.3 +/- 39.0 versus 83.1 /- 27.0 mm Hg, p < 0.05), whereas after 6 hours of preservation, no fu nctional difference was observed between the microperfused and the imm ersed hearts. Hearts were also studied using myocardial biopsy specime ns taken at the end of the preservation. The biopsy specimens were ana lyzed for high-energy phosphates. After 6 hours of preservation, the m icroperfusion group showed higher levels of adenosine triphosphate and total adenine nucleotides (adenosine triphosphate + adenosine diphosp hate + adenosine monophosphate) (respectively, 4.60 +/- 0.5 mumol/gm a nd 5.98 +/- 0.5 mumol/gm fresh tissue) versus the cold storage group ( respectively, 3.10 +/- 0.4 mumol/gm and 3.75 +/- 0.4 mumol/gm). These studies show the beneficial effect of the microperfusion apparatus com pared to immersion for long-term heart preservation.