Non-invasive methods of the evaluation of obliterative disease of the subclavian or innominate artery.

The preoperative investigation of 25 patients referred for evaluation of subclavian artery obliteration is reported. Non-invasive methods were used prior to angiography to assess arm circulation and the direction of blood flow in the vertebral artery. A retrograde flow in one vertebral artery was found in 18 patients, but only 7 had symptoms judged to be caused by the reversal of flow. In only one patient was the arm circulation so impaired as to justify the diagnosis of arm claudication. A high frequency of carotid lesions was found on the angiograms. The report demonstrates that in cases of suspected subclavian steal and/or arm claudication due to a subclavian artery obliteration, non-invasive methods should be used to screen the patients before angiography. In many cases it will be found that symptoms cannot be attributed to steal or impairment of the arm circulation and therefore angiography is not indicated. However, in some cases signs of a coexistent carotid lesion may still necessitate angiography.