The Effects of Antibiotics and Storage on the Viability and Ultrastructure of Fibroblasts in Canine Heart Valves Prepared for Grafting1

Abstract

Aortac und pulmonary valve cusps from mongrel dogs were suspended in a nutrient medium and exposed for one week at 4°C to an antibiotic solution and were thereafter stored in nutrient medium without antibiotics at 4°C. The cusps were subjected to tissue culture and microscopic examination at intervals ranging from one day to five weeks after collectzon. Growth of fibroblasts was noted on tissue culture in 93% of cusps after 24 hours, in 61% after one week and in 15% after two weeks. There was no growth beyond two weeks. Elertron microscopic examination showed progressively severe ultrastructural changes recognizable after the cusps had been in the antibiotic solution for 24 hours. This and other studies on human material make it clear that satisfactory function of antibiotic‐sterilized valve allografts is not primarily dependent on viable graft fibroblasts.