Relative safety of intravenous digital subtraction angiography over other methods of carotid angiography and impact on clinical management of cerebrovascular disease.

Data from a multicentre survey based on three London teaching hospitals on the relative safety and clinical utility of intravenous carotid digital subtraction angiography (DSA) over intra-arterial DSA and conventional carotid angiography are presented. The incidence of stroke during intra-arterial DSA was 0.7% (n = 538) and during conventional angiography was 0.8% (n = 780). The incidence of stroke during intravenous DSA was zero (n = 3710). When it constituted the initial investigation, intravenous DSA achieved a 93.8% replacement value over intra-arterial studies as a whole (n = 474) and 89% replacement value for patients having carotid endarterectomy (n = 99). It was also noted that the installation of DSA equipment at one unit coincided with a sixfold increase in the number of carotid angiographic examinations and an almost threefold increase in carotid endarterectomies.