Extracranial-Intracranial Bypass Procedures

Extracranial–intracranial bypass procedures are performed either for purposes of flow augmentation in the setting of cerebrovascular occlusive disease, or for flow replacement in the setting of planned vessel sacrifice. Flow replacement bypass is typically performed for the treatment of complex aneurysms, and its role is well accepted, although infrequently required. Extracranial–intracranial bypass for flow augmentation is a well-established treatment in moyamoya disease, but has a limited role for atherosclerotic occlusive disease treatment due to evidence failing to support its role in routine management in this setting. In this chapter, we briefly discuss the indications for extracranial–intracranial bypass, patient selection, and different types of bypasses, which can be offered for flow augmentation and flow replacement.