Endothelial preservation of the minimally manipulated saphenous vein composite graft: histologic and immunohistochemical study.

OBJECTIVE: We evaluated the efficacy of minimally manipulative surgical strategies to harvest the saphenous vein for use in a Y-composite graft based on the left internal thoracic artery in terms of preservation of endothelial structure and function.
METHODS: Twenty patients who underwent off-pump coronary revascularization using the saphenous vein in a Y-composite graft based on the left internal thoracic artery were studied. The saphenous vein was harvested from each patient with minimal manipulation. An excess saphenous vein segment was removed before dilatation (control group), and a second segment was removed after dilation performed using a pressure-sensing syringe (conventional group). A third segment was obtained from a Y-composite vein graft dilated by flow and pressure from the left internal thoracic artery (composite group). Hematoxylin-eosin staining and immunohistochemistry using antibodies against CD31, CD34, von Willebrand factor, and endothelial nitric oxide synthase were performed. A generalized estimating equation was adopted for statistical analysis.
RESULTS: Histologic and immunohistochemical studies revealed better endothelial preservation in the composite and control groups than in the conventional group (P < .01 in each). The composite group saphenous vein showed a lower grade of endothelial integrity than the control group saphenous vein based on hematoxylin-eosin staining, CD34 immunohistochemistry, and nitric oxide synthase staining (P < .001 in each).
CONCLUSIONS: Harvesting of the saphenous vein using minimal manipulation for use in a Y-composite graft based on the left internal thoracic artery preserved endothelial structure and function when compared with manually dilated saphenous vein harvesting.