An intracranial bypass is a surgical procedure used to restore blood flow within the brain by connecting a blood vessel from outside the brain to a vessel within the brain. Similar to cardiac bypass surgery, the goal of intracranial bypass is to prevent strokes by rerouting blood around the damaged blood vessel.

It is most often performed when the patient has severe carotid artery stenosis that produces symptoms such as weakness and speech difficulties. The procedure can also be performed on an aneurysm that cannot be treated through surgical clipping or endovascular embolization. Skull base tumors that invade the artery can also be treated using intracranial bypass surgery.