The radiographic anatomy of surgical extracranial-intracranial anastomoses.

Microvascular surgical techniques have been developed that allow anastomosis between extracranial arteries and cortical branches of intracranial arteries distal to a stenotic, occluded, or diseased arterial segment. Indications for this procedure other than cerebrovascular occlusive disease are discussed. The radiographic anatomy of the various surgical bypasses is described.