Results of the international extracranial/intracranial bypass study. Implications for neuroradiologists.

A randomized trial to determine whether bypass surgery would benefit patients with appropriate atherosclerotic lesions followed 1377 patients for almost five years, and found no benefit from surgery. This negative result has a number of potential implications for neuroradiologists including the expectation for other randomized trials to be carried out, such as for carotid endarterectomy, and the need for neuroradiologists to carry out trials for embolization of cerebral arteriovenous malformations and angioplasty of stenotic cervical or cranial vessels. We are reminded that, ultimately, the clinical outcome is the real measure of procedures, not pretty pictures.