Effect of skeletonizing dissection on the internal thoracic artery.

Abstract

Skeletonization of the internal thoracic artery (ITA) produces greater length for coronary bypass grafting. We studied the effect of skeletonization on the morphology, histology, and tissue viability of the ITA wall. Six mongrel dogs underwent unilateral ITA dissection; the contralateral ITA was the control. Study periods were 3 weeks (n=3) and 12 weeks (n=3). At sacrifice, the entire anterior chest wall was removed and dynamically fixed with formalin. Extensive histologic comparisons were performed on three tissue blocks taken from each ITA, 2, 8, and 24 cm from their origin. Flows at the end of the study were comparable to measurements taken during operation, immediately after skeletonization. Grossly, the ITA wall was not injured by skeletonization and there was no adventitial hematoma or bleeding from the sealed branch ends. Microscopic observations showed intact, normal wall structures. Histologic data showed no major significant difference between controls and skeletonized ITAs. Careful skeletonizing dissection is not detrimental to the integrity of ITAs, which justifies their use for myocardial revascularization.