Minimal amounts of hyaluronidase in HTK or UW solution substantially improve the recovery of preserved hearts.

Rat hearts were preserved by simple storage for 18 h at 0-1 degree C and reperfused parabiotically with whole blood from a host rat. The preservation solutions used for flush perfusion and storage were the commercial solutions EuroCollins, HTK, or UW with or without adding 40 mg/l hyaluronidase or EuroFlush-Glutathione (EFG) solution, especially designed for prolonged heart storage. All solutions were filtered (0.45 micron) before use. The functional recovery was measured using a latex balloon in the left ventricle for LVP, dp/dt, and isotonic stroke volume. The metabolic recovery as well as the edema formation was determined from freeze-clamped myocardium at the end of reperfusion. In hearts preserved with hyaluronidase-containing solutions, the edema formation during reperfusion was reduced combined with an improvement in the coronary flow. Functional and metabolic recovery were improved in these hearts with significant increase in the stroke volume and ECP in all groups versus hearts preserved in the hyaluronidase-free basic solutions. The effectiveness of HTK preservation was significantly improved by hyaluronidase in all parameters measured in our study. The best functional and metabolic recovery was found in hearts preserved by HTK + H- or EFG-solution. Thus, preservation solutions containing hyaluronidase, especially HTK + H and EFG, seem best suited for the prolonged storage preservation of the heart.