ALLOGRAFT HEART-VALVE VIABILITY AND VALVE-PROCESSING VARIABLES

Background. The impact of allograft valve viability on valve durabilit y remains controversial. Analyses of our clinical results have demonst rated the superiority of the cryopreserved valve viable at the time of implantation over the 4 degrees C stored valve nonviable at the time of implantation. In this study, we quantitatively assessed the effects on viability of current and past valve-processing protocols at The Pr ince Charles Hospital. Methods. The viability of pulmonary valves was quantitatively analyzed by thin-layer autoradiography to assess the ef fects of donor type, antibiotics, and valve storage. Results. Control valve segments obtained from beating-heart donor valves had a higher i nitial viability (0.92 +/- 0.02) than nonbeating-heart donor valves (0 .66 +/- 0.03). Cryopreservation after low-dose antibiotic sterilizatio n significantly reduced viability to 50% to 60% of the control, and in the presence of amphotericin B, viability dropped further to 10% to 3 6% of the control. After 7 days' storage at 4 degrees C, viability was reduced to 2% of control and to 0% viability after 21 days. Conclusio ns. For maximal preimplantation viability, valves should be procured a s soon as possible after cessation of heart beat and should be cryopre served if they are not to be clinically implanted within 1 to 2 days. Amphotericin B should not be used in conjunction with cryopreservation if viability is to be maximized. (C) 1998 by The Society of Thoracic Surgeons.