Preview of a new trial of extracranial-to-intracranial arterial anastomosis

In 1985, the International Study of Extracranial-to-Intracranial Arterial A nastomosis demonstrated no benefit from extracranial-to-intracranial arteri al bypass operations in treatment of patients with extensive cerebrovascula r disease including those with occlusions of the internal carotid artery. I nterest in the potential use of extracranial-to-intracranial arterial bypas s operations, however, has been rekindled by evidence that some patients wi th occlusion of the internal carotid artery have a poor collateral circulat ion and a high risk for recurrent ischemic events. Other patients with adeq uate perfusion after occlusion have a low likelihood for recurrent stroke. Restricting surgical treatment to only those patients judged to have a high risk for recurrent stroke might improve the usefulness of the bypass opera tion. A new clinical trial proposed, testing the potential usefulness of ex tracranial-to-intracranial arterial bypass operations for treatment of care fully selected patients with occlusion of the internal carotid artery. Seve ral issues that are being addressed in this new trial are described in this article.