Utility of Screening for Cerebral Vasospasm Using Digital Subtraction Angiography

Background and Purpose-Cerebral arterial vasospasm (CVS) is a common complication of aneurysmal subarachnoid hemorrhage strongly associated with neurological deterioration and delayed cerebral ischemia (DCI). The utility of screening for CVS as a surrogate for early detection of DCI, especially in patients without clinical signs of DCI, remains uncertain. Methods-We performed a retrospective analysis of 116 aneurysmal subarachnoid hemorrhage patients who underwent screening digital subtraction angiography to determine the association of significant CVS and subsequent development of DCI. Patients were stratified into 3 groups: (1) no symptoms of DCI before screening, (2) ≥1 episodes of suspected DCI symptoms before screening, and (3) unable to detect symptoms because of poor examination. Results-Patients asymptomatic before screening had significantly lower rates of CVS (18%) compared with those with transient symptoms of DCI (60%; P<0.0001). None of the 79 asymptomatic patients developed DCI after screening, regardless of digital subtraction angiography findings, compared with 56% of those with symptoms (P<0.0001). Presence of CVS was significantly associated with DCI in those with transient symptoms and in those whose examinations did not permit clear assessment (odds ratio 16.0, 95% confidence interval 2.2-118.3, P=0.003). Conclusions-Patients asymptomatic before screening have low rates of CVS and seem to be at negligible risk of developing DCI. Routine screening of asymptomatic patients seems to have little utility. Screening may still be considered in patients with possible symptoms of DCI or those with examinations too poor to clinically detect symptoms because finding CVS may be useful for risk stratification and guiding management.