Viability studies of human valves prepared for use as allografts

The preimplantation viability status of pulmonary and aortic valves prepared for use as allografts by the methods in current use at Green Lane Hospital, Auckland was determined by autoradiography and culture. The valves were obtained from cadaver donors, disinfected in antibiotic solution and stored by cryopreservation. A group of 45 banked valves considered unsuitable for clinical use was assayed initially and very few were found to have viable fibroblasts in their leaflets. A series of 29 valves collected at postmortem examination then was assayed sequentially after each phase of the preparation procedure. Valves obtained within 24 hours of donor death usually retained considerable viability. However, in all but a minority of cases this declined markedly after antibiotic treatment and further still after cryopreservation, so that most valves were nonviable when thawed.