Abstract
We report a case of subclavian steal syndrome in which recanalization of the left subclavian artery by percutaneous transluminal angioplasty (PTA) resulted in global improvement of cerebral blood flow (CBF).
A 57-year-old diabetic male was admitted to our neurologic ward due to right homonymous hemianopsia and word amnesia. Coarse bruit was audible in the left supraclavian fossa and blood pressure measured in the left upper limb was lower by 39 mmHg than that in the opposite side. Digital subtraction angiogram revealed 90% stenosis of the left proximal subclavian artery, back flow in the left vertebral artery, and severe stenosis of the left internal carotid artery, as well. Left hemisphere was mainly perfused from the contralateral internal carotid artery and vertebral artery via the circle of Willis. CT scan showed low attenuated area in the territories of left posterior and middle cerebral arteries. Stenosis of the left subclavian artery was released by PTA with a balloon catheter so that flow direction in the left vertebral artery returned to forward. SPECT 99mTc-HMPAO) performed before and after the PTA demonstrated a significant recovery of CBF in the territories of both posterior and middle cerebral arteries. The flow improvement persisted in the follow-up SPECT performed 4 months later. Neurological abnormalities such as visual field defect and word amnesia are gradually improved after the PTA.
Subclavian steal syndrome is frequently accompanied with arteriosclerotic stenosis of the other major cerebral arteries. The present case suggests that normalization of vertebral flow can cause global CBF improvement by raising perfusion pressure at the Willis ring. Percutaneous transluminal angioplasty can be a first choice of treatment in cases of subclavian syndrome with ischemic events.
