Protecting the endothelial integrity of internal thoracic arteries

Previous functional studies on human internal thoracic arteries, comparing the effect of the traditional harvesting method (occlusion with a clip) with a method leaving the artery perfused, revealed considerably impaired endothelial function associated with enhanced contractility after clipping. We have now investigated whether these observations could be correlated (1) with plasma markers of endothelial dysfunction, and (2) with structural changes in the endothelial layer.

32 patients were randomly distributed into groups of clipped and perfused arteries. Arterial blood samples were obtained from both the artery and extracorporeal circulation to determine sP-selectin, sE-selectin, sL-selectin, and thrombomodulin using enzyme-linked immunosorbent assay. Arteries from three patients were examined by scanning electron microscopy.

Concentrations of sP-selectin and thrombomodulin were significantly higher in plasma from clipped arteries compared to perfused arteries, whereas sE-selectin and sL-selectin concentrations were similar within the groups. Scanning electron microscopy revealed significant structural changes and loss of endothelial cells in clipped arteries.

Biochemical and structural results support our findings that leaving the internal thoracic artery perfused preserves endothelial function in the arterial graft.