Stenting Versus Aggressive Medical Management for Symptomatic Vertebral Artery Stenosis

Posterior circulation strokes account for 20% of all strokes (2). Traditional studies cite a 5-year stroke rate ranging from 22%e 35% following an initial vertebrobasilar transient ischemic attack (TIA) or stroke (11, 14). Contrary to traditional beliefs, the overall risk of recurrent stroke in the posterior circulation is similar to the risk after an anterior circulation stroke, and likely higher in the acute phase (8). In one pooled analysis of 359 patients experiencing vertebrobasilar territory TIA or stroke, the 90-day risk of stroke after the presenting event was 9.6% in patients with vertebrobasilar stenosis versus 2.8% in those without (OR 3.7, 95% CI 1.2e11.0, P 1⁄4 0.012) (9). The authors noted a trend that this risk was higher with intracranial vertebrobasilar stenosis than extracranial vertebral stenosis (P 1⁄4 0.06). To mitigate this risk, aggressive medical management incorporating diet and lifestyle modification, control of hypertension, and the usage of statins and antiplatelet agents may be used (3, 5, 16). In addition, multiple individual case series have suggested that stenting vertebrobasilar lesions may be associated with a low-risk profile and subsequently low rates of referable TIAs or strokes (1, 10, 12, 13, 15). A systematic review of stenting symptomatic, atherosclerotic vertebrobasilar disease reported periprocedural TIA, stroke, and death rates of 1.6%, 1.3%, and 0.3%, respectively, across 313 cases with proximal vertebral artery disease (6). Over a mean follow-up period of 14.2 months, the post-treatment annual rate of TIA or stroke in the vertebrobasilar territory was 0.6%. Interestingly, for 283 cases of distal vertebrobasilar stenting, the periprocedural TIA, stroke, and death rates were 0.7%, 10.6% and 3.2%, respectively (6). The annual rate of subsequent vertebrobasilar stroke over a mean follow-up of 13 months after treatment was 1.9%. Thus although patients with symptomatic intracranial vertebrobasilar stenosis may have a greater risk of TIA or stroke without treatment (9), the risk of stenting may also be higher in this group (6). However, more specifically, a subgroup analysis from the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial demonstrated significantly higher periprocedural ischemic events in patients undergoing stenting of the basilar artery as compared with those undergoing stenting of the intracranial internal carotid, middle cerebral, or vertebral artery (7). Before the Vertebral Artery Stenting Trial (VAST) (3), subgroup analyses of 2 randomized control trials comparing stenting of symptomatic arterial stenosis to best medical management demonstrated no benefit of stenting for patients with vertebral artery stenosis (4, 5). In the Carotid And Vertebral Artery Transluminal Angioplasty Study (CAVATAS), 16 patients with