Subclavian steal with ipsilateral vertebral artery occlusive disease.

The classical subclavian steal syndrome is a larcenous vertebrobasilar insufficiency, secondary to retrograde flow in the vertebral artery. The authors present their experience with an unusual variant of subclavian steal in which the ipsilateral vertebral artery was completely or partially occluded, or arose from the aortic arch. These patients had symptoms typical of vertebrobasilar insufficiency--dizziness or brain stem transient ischemic attacks--despite steal through relatively small cervical collaterals to the obstructed subclavian artery. Physical findings of diminished pulses and blood pressure in the involved upper extremity are similar to those in the common form of subclavian steal. The alternate collaterals found in these patients are documented by angiography and other potential collaterals are reviewed. All three symptomatic patients were treated successfully by carotid-subclavian bypass or anastomosis of the subclavian to the common carotid artery. They have remained asymptomatic for 1 1/2 to 3 years following operation. The potential for development of subclavian steal in the absence of a vertebral artery to provide collateral flow adds another reason for abandoning vertebral artery ligation as an alternative treatment for the subclavian steal syndrome.