A calcified superficial temporal artery to posterior cerebral artery bypass mimicking occlusion.

A 65-year-old man had progressive vertebrobasilar insufficiency, including cerebellar infarction, despite aggressive use of antiplatelet agents (aspirin, dipyridamole) and anticoagulants (heparin, Coumadin). Angiography showed 99% stenosis at the origin of the right vertebral artery and 99% stenosis of the basilar artery proximal to both superior cerebellar arteries. Because the patient 's signs and symptoms were refractory to all medical therapy, an STA to posterior cerebral artery (PCA) bypass was performed. A CT scan obtained immediately after surgery showed a high attenuation of the ST A-PCA bypass (Fig . 1 ). This was apparent on bone windows as well , sug-