[A case of severe stenosis of bilateral distal vertebral artery successfully treated with anastomosis operation].

A 65-year-old male complained of loss of consciousness for several minutes, transient diplopia and dizziness. He had no neurological deficits nor abnormalities in MR imaging. However, flow velocity of bilateral vertebral artery on ultrasonography indicated severe stenosis of bilateral distal vertebral artery. Brain angiography revealed severe stenosis of bilateral distal vertebral artery as well as occlusion of right middle cerebral artery (MCA). Single photon emission CT (SPECT: ECD-RVR method with acetazolamide loading) showed decreased cerebral blood flow and poor perfusion reserve in bilateral cerebellar hemisphere and right MCA territory. Superficial temporal artery-superior cerebellar artery (STA-SCA) anastomosis was performed. The patient turned out to have no episodes of unconsciousness attack, transient diplopia and dizziness after operation. Cerebral blood flow (CBF) in the posterior circulation was also improved. Evaluating quantitative CBF measurement by means of ECD-RVR method was useful for evaluating CBF. In cases who have severe stenosis of bilateral distal vertebral artery with complaints of vertebrobasilar insufficiency, STA-SCA anastomosis may be one of the most effective treatments.