3 The procedure
3.1 The aim of extracranial to intracranial bypass for intracranial atherosclerosis is to increase blood flow in intracranial arteries to relieve symptoms of cerebral hypoperfusion or reduce the risk of stroke. Under general anaesthesia, the extracranial donor artery (usually the superficial temporal artery) is anastomosed to a superficial cerebral artery (usually a subpial middle cerebral artery branch) through a mini-craniotomy. Typically, an end-to-side anastomosis is used. A graft (for example a radial artery or a saphenous vein graft) may be needed to allow higher flow.
3.2 Careful pre-operative planning involving ultrasound, angiography, computed tomography (CT), single-photon emission CT scanning or brain reserve testing is needed.