Establishment of a heart valve homograft bank using existing facilities

Abstract

THE PROGRESS of cryobiology together with broadening surgical indications have increased the demand for heart valve homografts. Cryopreserved aortic valves have been implanted either in the sub-coronary position or as a complete aortic root replacement. Reconstruction of the right ventricular outflow tract for various forms of congenital heart defects has been performed with aortic or pulmonary homografts. Pulmonary valve homografts have been used for right ventricular outflow reconstruction during the “Ross” procedure. Mitral valve homografts are used for the replacement of the mitral valve in female patients of child-bearing age and in other patients who bears contraindications for anticoagulation. The disadvantages of homografts include limited availability and durability. Although some authors claim the durability of cryopreserved homograft to be superior to that of fresh homografts, other studies did not affirm this, and the different results are probably related to some extent to variability in the sterilization and the preservation protocols. On the other hand, it is widely agreed that cryopreservation increases the shelf life of homografts from a few weeks of the fresh antibiotic-preserved material to at least 5 years among cryopreserved grafts. Thus the problem of availability may be partly solved by using cryopreservation rather than “fresh” grafts, and by establishing more homograft laboratories (“banks”) in remote areas. Establishing an independent homograft bank is costly. We sought to establish an independent bank at no additional cost as a model that can be implemented in any medical center containing some form of tissue bank (eg, a bone marrow bank).