Effects of harvesting technique on endothelial inflammation and nitric oxide production in saphenous vein grafts

Background: In this study, we investigated the effects of harvesting technique in saphenous vein grafts (SVG) (either conventional or endoscopic) on endothelial integrity, inflammation, and nitric oxide (NO) synthesis. Methods: Segments of 20 SVGs were harvested from 20 patients (23 males, 17 females; mean age 65.6 +/- 6.3 years; range 43 to 78 years) undergoing coronary artery bypass graft (CABG) surgery with the endoscopic (group 1) or conventional (group 2) technique. Saphenous vein specimens were stored in heparinized blood for one hour at the room temperature. As a marker of preserved endothelial function, nitric oxide (nitrate, NO3 and nitrite, NO2) levels in the SVGs were measured by means of the Greiss method. Saphenous tissual myeloperoxidase (MPO) activity, as a marker of neutrophil infiltration into the saphenous vein graft endothelium, was also measured in each group. This measurement revealed the extent of SVG endothelial damage and inflammation resulting from neutrophils. Results: Nitric oxide formation, as NO3 plus NO2, (group 1=34.18 +/- 5.43 mu M versus group 2=25.73 +/- 2.52 mu M, p<0.001) was higher in endoscopically harvested SVGs as compared to conventionally harvested SVGs. Saphenous tissual MPO activity (group 1=6.71 +/- 0.86 nm/min versus group 2=9.11 +/- 0.94 nm/min; p<0.001) was significantly lower in endoscopically harvested SVGs as compared with conventionally harvested grafts. Conclusion: Neutrophil infiltration into the vascular endothelium and neutrophil-induced endothelial injury is reduced in endoscopically harvested SVGs. Also, endothelial NO synthesis is better preserved in endoscopically harvested SVGs. These results suggest that endoscopic harvesting techniques can be used without major detrimental effects on vascular endothelial function and integrity in SVGs.