If the bypass is from outside of the head to inside of the head, it is referred to as an extracranial-to-intracranial (EC/IC) bypass. This can be a helpful procedure in select patients with appropriate clinical circumstances. Brain bypass operations are carried out by a relatively few neurosurgeons with experience in this area of neurovascular surgery.
There are two types. The first type is called a superficial temporal artery to middle cerebral artery bypass or STA-MCA. The superficial temporal artery (STA) normally provides blood to the face and scalp and can safely be surgically disconnected from the scalp and attached to the affected brain vessels. This operation is performed to decrease the risk of stroke in a small subset of patients. The second type of bypass utilizes a transplanted vessel from the leg (saphenous vein bypass graft or SVBG) or arm (radial artery bypass graft or RABG) to connect an artery in the neck to a large brain vessel. These types of bypasses provide more flow than STA-MCA. SABG or RABG are utilized primarily when a large vessel of the brain needs to be removed in order to cure an untreatable aneurysm, or a skull base tumor that involves a major brain vessel.
ELANA (Excimer Laser Assisted Non-occlusive Anastomosis) is a new technique used to create bypasses without closing the main bloodstream. ELANA is mostly used to treat giant intracranial aneurysms (aneurysms larger than 2.5 cm wide) or to give new blood supply to patients with an occluded artery to the brain (ischemia). Dr. Miller is certified to use this innovative procedure.