Histomorphological studies of the distal internal thoracic artery which support its use for coronary artery bypass grafting.

The use of the internal thoracic artery (ITA) for myocardial revascularization in coronary artery disease increased because of its relative immunity to atherosclerotic obstruction. This study investigated the distal part of the vessel, the region of anastomosis by means of histology to focus the visualization of this region of interest. The histological examination of arterial segments showed minor intimal thickening in 48 out of 100 patients. Twelve patients demonstrated a severe intimal thickening, the residual patients were without any changes. In 52% the elastic type dominated in the distal part. Hybrid and muscular patterns were found in 22 and 26%, respectively. The media could be classified into three different types: muscular, hybrid and elastic type. There was no correlation concerning the different histological type and the incidence of intimal thickening. No evidence whatsoever of atherosclerotic lesion was encountered in any of the investigated vessels. There is no limitation in the use of the distal part of the ITA for coronary artery revascularization.