Cerebral vasospastic vessels: histologic changes after percutaneous transluminal angioplasty.

PURPOSE

To investigate histologic changes before and after percutaneous transluminal angioplasty (PTA) in experimental cerebral vasospasm in comparison with normal vessels.

MATERIALS AND METHODS

In seven monkeys, vasospasm was induced in the subarachnoid space. After 7 days, PTA was performed. Microscopic studies were performed in vasospastic vessels. In two animals, vasospasm was induced but angioplasty was not performed. The controls were two animals without vasospasm who underwent only contralateral angioplasty.

RESULTS

Angiography after vasospasm revealed marked narrowing but dilatation after PTA, without changes in distal spastic vessels. Specimens after PTA showed platelets that covered denuded endothelium, stretching, and focal dehiscence of internal elastic lamina and altered myocytes in media. Myocytes were deformed and arranged irregularly. These changes were not uniform.

CONCLUSION

The prolonged effect of PTA may be caused by mechanical damage of myocytes and the nonuniformity of histologic changes in vascular walls.