Morphological changes in normal canine basilar arteries after transluminal angioplasty

The balloon catheter technique is being utilized in various intravascular procedures and transluminal angioplasty, but the type of morphological changes which take place in intracranial vessels after balloon inflation and dilatation are still unknown. This study reports on morphological changes in normal canine basilar arteries after transluminal angioplasty (TA) with 1.5 Atmospheres of inflation pressure and 30% dilatation. Histological changes 1 h after TA consisted of denudation of endothelial cells, deposition of fibrin which covered the denuded endothelium, stretching and focal dehiscence of internal elastic lamina and altered myocytes in media. These morphological changes were more prominent when the balloon was inflated longer. Seven days after TA, however, the endothelium had been regenerated almost completely, while slight chronic changes still remained in the internal elastic lamina and media. Angiographical and morphometrical analyses did not disclose any significant differences. This report proposes that under some conditions intra-arterial inflation and dilatation of the intracranial arteries causes reversible changes, which are noted mainly in the endothelium. In addition, a new in vivo experimental model which could be of use for physiological or pathophysiological investigations of intracranial arteries is introduced.