Cytotoxicity of various crystalloid solutions to the endothelial cells of autologous grafts

Abstract

Harvesting and storage may influence the early failure of autologous grafts. We studied the endothelial layer of human saphenous veins (HSV) and bovine internal mammary arteries (BMA) after a two-hour storage period in comparison to vessel segments prepared immediately after harvesting. The storage solutions were 0.92% NaCl, 0.9% NaCL heparinized, Ringer's Lactate (RL), heparinized blood or Bretschneider's cardioplegic solution. To visualize the endothelial cell damage, specimens were stained with silver nitrate. The surface covered by morphologically intact endothelial cells was computed in percent. In a perfusion model using the carotid artery of rabbits, the increase of the permeability of the endothelium after two hours' perfusion was investigated (n = 5 each). In native HSV-segments 70.8 +/- 4.5% of the endothelium were found to be morphologically intact. The figures for stored grafts were: 14.7 +/- 4.4% (NaCl), 0.5 +/- 0.3% (hep. NaCl), 16.0 +/- 4.6% (RL), 37.2 +/- 5.3% (hep. blood) and 50.0 +/- 4.2% (Bretschneider). Comparable results were found with BMA specimens. BMA: 98.3 +/- 2.1% (native), 39.2 +/- 3.3% (NaCl), 8.4 +/- 3.5% (hep. NaCl), 11.2 +/- 4.8% (RL). 67.0 +/- 6.1% (hep. blood) and 78.1 +/- 4.7% (Bretschneider). In accordance with these results the increase of the permeability of the endothelial cell layer of the carotid artery of rabbits was significantly less after perfusion with Bretschneider's solution. The condition of the endothelial cells of autologous grafts at the time of implantation was found to be clearly dependent on the type of solutions used for perfusion and immersion. In comparison to all crystalloids studied in this series, Bretschneider's cardioplegic solution proved to be superior.