CEREBRAL ANGIOGRAPHY IN THE EVALUATION OF PATIENTS WITH CEREBROVASCULAR DISEASE

Abstract

Accurate visualization of all of the extracranial and intracranial vasculature, including serial studies for evaluation of collaterals and circulatory physiology is essential before undertaking any therapeutic measures for patients with evidence of ischemic cerebrovascular disease. The methods now at our command make it possible to identify vascular lesions in 80 per cent of patients with cerebrovascular disease. In order to achieve a complete picture of extra-or intracranial circulation one must obtain excellent contrast filling and technically good films of the entire brachiocephalic arterial tree. Films must be obtained in rapid succession and must be taken during a period of time long enough to make visible not only the anatomy but the physiology of flow and collateral circulation. The techniques of angiography used at New York University Medical Center include right and left percutaneous brachial angiography and left carotid angiography. Biplane films of the origins of the vessels and their course in the neck are taken in the oblique projection during the brachial examination. Biplane head and neck films are obtained during both brachial and carotid angiograms. Extracranial stenoses and occlusions are readily identified. Such lesions are most commonly found at the common carotid bifurcation and at the vertebral artery origin. Intracranial stenoses and occlusions may occur in conjunction with extracranial disease or independently. Collateral channels of every conceivable type have been seen. An understanding of the alteration of flow caused by the formation of collateral beds is basic to an understanding of ischemic phenomena. Acute major vascular occlusions are often associated with edema of the involved hemisphere, and in such instances these findings suggest a grave prognosis. Although the status of surgical and medical therapy is not entirely clear at this point, it is probable that surgical removal of certain stenotic lesions in particular cases of stenotic cerebrovascular disease may offer a more favorable prognosis. It is imperative that the study of the entire intra- and extracranial circulation be completed before a rationale for therapy can be developed.