Use of interposition long vein grafts in extracranial-to-intracranial bypass operations

Extracranial to intracranial bypass using an interposed saphenous vein has become a valuable cerebrovascular surgical procedure in the past 30 years. Most commonly, the vein is connected to the cervical carotid system proximally and the intracranial internal carotid or middle cerebral artery distally. Bypass procedures to augment the posterior circulation are also possible. These procedures have been used primarily to increase cerebral blood flow to an ischemic cerebral hemisphere and to prevent ischemic complications when a major vessel, such as the internal carotid or vertebral artery, must be sacrificed to treat a skull base tumor or unclippable aneurysm. Meticulous attention to the technique of vein harvest, tunneling, anastomosis, and restoration of flow will help ensure high patency and low complication rates. The history, indications, technique, complications, and results of interposition long vein grafts in extracranial to intracranial bypass operations is reviewed.