Histological assessment of orthotopic aortic valve leaflet allografts: its role in selecting graft pre-treatment.

Histopathological studies of human cardiac valve grafts recovered at autopsy or re-operation, together with long-term clinical follow-up of valve graft recipients, have indicated that the success of grafts is largely dependent upon the extent to which they are replaced by host fibrous connective tissue. To find the valve preparation technique with least inhibitory effect on tissue ingrowth after grafting, various sterilizing and storage procedures were evaluated using a series of aortic valve leaflet allografts in dogs. To facilitate evaluation, a method for rapidly assaying relative degrees of colonization of grafts was first devised. Application of this method has unequivocally identified a newly-formulated antibiotic solution as the pre-treatment most compatible with host tissue ingrowth.