Effects of Ultrasonic Skeletonization of the Gastroepiploic Artery on Endothelial Nitric Oxide Production

Abstract

Objective The right gastroepiploic artery (GEA) is a reliable conduit for coronary artery bypass grafting. Recently, ultrasonic skeletonization in graft harvesting has attracted attention as an alternative technique to increase the length and caliber size of grafts. The influence of GEA skeletonization using an ultrasonically activated device with that using an electrosurgical unit was compared from the viewpoint of production of nitric oxide (NO). Methods Fourteen pigs were used in this study. The GEA were harvested using an ultrasonically activated device (group ultrasonically activated device [USAD], n = 7) or electrocautery (group E, n = 7). Blood sampling was performed at the following three times from the distal end of the GEA: (1) preskeletonization, (2) pedicle, and (3) postskeletonization. Plasma NOx (NO metabolites) levels were measured by chemiluminescent assay. Moreover, in excised specimens, the expression of nitric oxide synthase was examined immunohistologically. Results In group USAD, the preskeletonization basal level of plasmaNOx in GEA was 25.7 ± 10.9 μmol/L, which then increased to 26.9 ± 10.5 μmol/L (pedicle) and 32.2 ± 12.1 μmol/L (postskeletonization). In group E, the preskeletonization basal plasma NOx level in GEA was 28.9 ± 11.4 μmol/L, which changed to 27.5 ± 8.9 μmol/L (pedicle) and 21.8 ± 8.3 μmol/L (postskeletonization). The results of multivariate analysis indicated that the patterns of changes in plasma NOx level were significantly different in both groups (P = 0.024). In group USAD, post hoc multiple comparison tests revealed a significant difference between preskeletonization and postskeletonization (P = 0.037). Conclusions Ultrasonically skeletonized GEA showed increased effective graft length, higher free flow capacity, and increased endothelial NO production than that prepared using an electrosurgical unit.