Abstract
The vasodilation mode and degree of the invasion "caused by balloon angioplasty for vasospasm after subarachnoid hemorrhage were experimentally examined. Eleven main cerebral arteries of the circle of Willis were collected in autopsies of 11 patients who died of vasospasm. Using the 5 arteries, in vitro angioplasty was performed at 1 atm for various time duration, ranging from 10 seconds to 5 minutes on 3 arteries (Group A) and 10 times at 3 atm for 1 minute on 2 arteries (Group B). In light microscopy, the treated site of Group A showed compression of the intima, streching of the media and the disappearance of vacuolization of the muscular cells. However, there was neither rupture nor fragmentation of the intima. In scanning electron microscopy, the unevenness seen at the nontreated intima was smooth out at the treated sites. When compared Group A and B, no remarkable histopathological differences were identified. On the other hand, in order to evaluate the effect of angioplasty under conditions similar to clinical state, the remailling 6 spastic arteries of 5 cm length, were quickly implanted in' the carotid or femoral artery of mongrel dogs under general anesthesia. Using fluoroscope, angioplasty was also performed in the same conditions of Group A and B as in vitro study. The implanted artery showed dilatation of over 30% on angiography after angioplasty. Then, the implanted arteries were removed and submitted to histological examination. In vitro angioplasty performed 10 times at 1 atm or 3 atm for 1 minute showed almost the same results in histological changes with in vitro angioplasty. In conclusion, it was found that in vitro angioplasty performed at least 10 times at 1 atm for 1 minute provided sufficient dilatation of spastic arteries without damage to the arterial walls.
