Abstract
We report a case in which stepwise revascularization was performed for highly calcified and hemodynamically compromised internal carotid artery (ICA) stenosis with contralateral ICA occlusion to prevent intraoperative ischemic stroke and postoperative hyperperfusion. A 74-year-old man having vertigo was initially diagnosed with asymptomatic lacunar infarction of the left thalamus. Additional examinations revealed severe stenosis of the right ICA with occlusion of the left ICA, aplasia of the right posterior communicating artery, and anastomosis of each branch from the right vertebral and occipital arteries. Single photon emission computed tomography (SPECT) showed bilateral hemispheric hypoperfusion, which suggested the risks of intraoperative ischemic stroke during ICA cross clamping for carotid endarterectomy (CEA) and postoperative hyperperfusion syndrome. To prevent these risks, we performed right superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis prior to CEA. Vertebral angiograms obtained after anastomosis indicated blood flow in the MCA territory via the occipital artery and STA, and SPECT confirmed improvement in cerebral hemodynamics. One month later, right CEA using a shunt was successfully performed without any intraoperative ischemic event. The patient experienced no symptom of ischemic stroke or hyperperfusion syndrome. Stepwise revascularization may prevent postoperative hyperperfusion in patients with severe hemodynamic compromise. In addition, increasing the cerebral blood flow by STA-MCA anastomosis would prevent ischemic events during CEA. However, the indications should be strictly limited to the angioarchitecture of anastomosis between the vertebral and occipital arteries, as in this case.
