Determination of Residual Antibiotics in Cryopreserved Heart Valve Allografts

Cardiovascular allografts are systematically incubated in antibiotics for their decontamination, and the antibiotics are removed before allograft implantation. We studied the occurrence of antibiotic residues in allograft valves. MATHODS: 12 experimental allografts were analyzed in this study. The concentration of the residual antibiotics was determined by high-performance liquid chromatography and the results were expressed as microgram per gram of allograft tissue. RESULTS: The initial analysis showed that only vancomycin HCl and lincomycin HCl were retained in the allograft, whereas no traces of polymyxin B sulfate were detected in the tissue samples. Furthermore, the values found for the antibiotic residues in the extracted solution from the allografts were similar to the initial results: Vancomycin and lincomycin were detected in very low concentrations and no polymyxin B residues were observed. According to the World Health Organization (WHO), the maximum daily doses for vancomycin, lincomycin and pol-ymyxin B are 2.0, 1.8 and 0.4 g, respectively. The thresholds for reporting degradation products are 0.05% for vancomycin and lincomycin and 0.1% for polymyxin B. The residual values for the two detected antibiotics were largely below 0.05%. CONCLUSIONS: Antibiotic residues in the allograft valves do not present any risk for their recipients. Increased allograft resistance to infections is probably due to the retention of antibiotics in the tissue.