Noninvasive cerebrovascular evaluation: a prerequisite for angiography?

Results of cerebrovascular evaluation were reassessed in 768 patients to determine whether angiography performed in unselected patients was safe and economically efficient, and whether previous noninvasive screening was sensitive enough and effective in increasing the yield of subsequent angiography. In 543 patients undergoing angiography without previous noninvasive screening, positive results were obtained in 21 percent. Complications included hemorrhage (2.4 percent), neurologic deficit (2.2 percent), and death (0.2 percent). Of 225 patients undergoing previous screening with Doppler, ophthalmoplethysmography, and carotid phonoangiography, none with negative screening results had subsequent cerebrovascular complications. Of 82 patients having positive noninvasive test results, 53 underwent angiography with a 74 percent yield of positive results. Twenty-nine had no angiography or corrective therapeutic action. Of these, 3 percent died after a cerebrovascular accident, and 21 percent developed complete stroke (mean follow-up 3 years). Noninvasive screening reliably eliminated necessity for angiography in 64 percent of patients while increasing the angiographic yield from 21 to 74 percent. Therefore, performance of cervicoencephalic angiography is asymptomatic and unselected patients cannot be condoned any longer. Likewise, positive noninvasive screening results should not be ignored because in the absence of treatment, death (3 percent) and permanent neurologic deficit (21 percent) occur over a 3 year period.