DAMAGE TO ARTERIAL AND VENOUS ENDOTHELIAL-CELLS IN BYPASS GRAFTS INDUCED BY SEVERAL SOLUTIONS USED IN BYPASS-SURGERY

The purpose of our study was to evaluate the cytotoxicity of incubatio n solutions used in heart surgery to endothelial cells. The endothelia l layer of human saphenous veins (HSV) and bovine internal mammary art eries (BMA) and veins (BMV) were studied after a two-hour storage inte rval and compared with control vessel segments prepared immediately af ter harvesting. To visualize the endothelial cell damage, specimens we re stained with a silver nitrate technique. The surface covered by lig ht-microscopically intact endothelial cells was computed in percent. I n the control HSV segments 70.8 +/- 4.6% of the endothelium were found to be morphologically intact. The results for stored HSV segments wer e 50.0 +/- 4.2% (Bretschneider's solution), 14.8 +/- 4.5% (physiologic al saline), 0.45 +/- 0.1% (physiological saline with heparin), 16.7 +/ - 4.7% (Ringer's lactate) and 37.2 +/- 5.3% (heparinized blood). Compa rable values obtained with BMA specimens were 98.3 +/- 0.7% (controls) , 78.1 +/- 4.7% (Bretschneider's solution), 39.2 +/- 3.3% (physiologic al saline), 8.4 +/- 2.0% (physiological saline with heparin), 11.3 +/- 1.7% (Ringer's lactate) and 67.8 +/- 6.2% (heparinized blood). A simi lar trend was found with BMV segments: 85.2 +/- 4.7% (controls), 75.6 +/- 6.0% (Bretschneider's solution), 49.5 +/- 8.9% (physiological sali ne), 5.95 +/- 0.7% (physiological saline with heparin), 6.2 +/- 0.7% ( Ringer's lactate) and 54.3 +/- 5.1% (heparinized blood). In conclusion , Bretschneider's solution proved to be superior for storage of bypass grafts in comparison to all other tested solutions in this series.