Safety of Angioplasty for Intracranial Artery

We read with interest the article “Intracranial Angioplasty: Experience and Complication” by Takis et al (1) in the October 1997 issue of the American Journal of Neuroradiology. The authors performed angioplasty in intracranial arteries in 10 patients with TIA or minor stroke and reported a relatively high rate of intraprocedural complications, including vasospasm (63%), dissection (25%), and compromise of perforating vessels (25%). We speculate that perhaps technical differences in their procedures may have contributed to their unfavorable results. In our previous study of angioplasty for the basilar artery (2), we suggested less invasive techniques, such as lowering inflation pressure (<3 atm), dilating fewer times (once or twice), and using a smaller balloon catheter (2.0 mm). It is also important to inflate the balloon catheter slowly. These techniques could minimize the intimal damage and prevent occlusion of the perforating artery and excessive dissection. In addition, significant hemodynamic disturbance is reported to occur only with more than 70% stenosis; further dilatation of less than 50% stenosis may not always be necessary to achieve adequate cerebral blood flow. The purpose of angioplasty should be to provide sufficient perfusion to reduce ischemic symptoms, not to achieve an angiographic cure, which is often associated with an unacceptable complication rate. Nevertheless, the restenosis rate of our techniques is to be determined by a larger number of patients and long-term follow-up data. In our limited experience with 25 cases that have been followed up more than one year, the restenosis rate has been less than 10% (two cases). This is relatively low when compared with the reported data regarding angioplasty for the intracranial artery (30% [3]) and angioplasty for the coronary artery. Most important, our complication rate, based on our 30 cases, is much lower (6%, unpublished data) than that reported by Takis et al.

In general, mechanical vasospasm is temporary and responsive to vasodilators, as suggested by the authors. Persistent vasospasm is mostly related to arterial dissection, particularly the dissection of small vessels, such as intracranial arteries, and may not always be apparent on cerebral angiograms. Because silent dissection does not commonly cause stroke, systemic heparinization administrated for 3 days after angioplasty is the preferred treatment of patients with potential arterial dissection in our institution.