The subclavian steal syndrome: a review.

Proximal occlusions of the subclavian and innominate arteries may create a cerebrovascular insufficiency syndrome. The syndrome is generally characterized by neurologic symptoms of the vertebral-basilar arterial distribution. Blood is siphoned along the vertebral artery because of the low pressures distal to the occlusion. The clinical syndrome is best confirmed by a thoracic arch aortogram. Treatment is reserved for symptomatic patients. An extra-thoracic revascularization of the distal subclavian artery is the preferred operation.