Effects of antibiotics on the endothelium of fresh and cryopreserved canine saphenous veins.

To determine if antibiotic solutions for potential use in antimicrobial treatment of tissues were detrimental to cell viability, canine saphenous veins were exposed to three different antibiotic solutions at 37 degrees C for 12 h. Viability was determined by tissue culture, utilizing a limiting dilution assay. The antibiotic series included two formulations currently used for the preservation of heart valves and a new formulation containing imipenem, a broad spectrum beta-lactam. Currently used antibiotic regimes and imipenem with gentamicin resulted in a decrease of 30 to 50% of the viable endothelial cells within 12 h. Exposure of the saphenous veins to imipenem or imipenem combined with amphotericin B had no adverse effects on the viability of the endothelial cells with 12 h exposure. However, veins exposed to amphotericin B were more susceptible to subsequent damage during freezing and thawing than veins frozen after incubation with either imipenem alone or imipenem combined with flucytosine. These studies indicate that imipenem combined with flucytosine is suitable for use with vein grafts.