Intraoperative and histochemical comparison of the skeletonized and pedicled internal thoracic artery.

Background: Skeletonization of the internal thoracic artery (ITA) has advantages, but the variation of ITA preparation may be traumatic for the arterial wall. We sought to compare intraoperative results and endothelial nitric oxide synthase (e-NOS) expression on the vessel wall after left ITA harvesting with skeletonization and the conventional technique.

Methods: A prospective evaluation of 84 consecutive patients undergoing coronary artery bypass grafting was performed: 40 patients with skeletonized and 44 patients with pedicled left ITA. The lengths of ITA and free ITA blood flow were measured. Distal ITA segments were analyzed histopathologically and stained by antibodies against e-NOS.

Results: In the skeletonized group, the length of the ITA were significantly longer than in the pedicled group (15.7 +/- 0.4 cm versus 19.0 +/- 0.6 cm; P = .001). Also, the free-flow capacity of the ITA was significantly higher than in the pedicled group (62.4 +/- 4.8 mL/min versus 88.6 +/- 6.9 mL/min; P = .001). e-NOS expressions on endothelial cells were similar between the groups. Dense e-NOS immunostaining was observed in vaso vasorum of the adventitia in the pedicled group. However, there was not any e-NOS immunostaining in vaso vasorum of the adventitia in the skeletonized group.

Conclusions: Although skeletonization of the ITA is a more technically demanding procedure, it provides some advantages such as increased available graft length and reduced sternal devascularization. This technique did not have any detrimental effects on the endothelial cell lining and e-NOS expressions on the endothelial layer. To reach a definitive judgment for using skeletonized ITA, we need information about the long-term angiographic patency rates.