Abstract 1122‐000192: Transient Blood Flow Reversal in The Vertebral Artery As an Embolic Protection Method During Angioplasty/Stenting

Introduction : Approximately 20% of all acute ischemic strokes occur in the vertebrobasilar (VB) circulation. Similar to carotid stenosis, symptomatic vertebral artery (VA) stenosis is associated with a high risk of stroke recurrence. The use of embolic protection devices for recanalization in the setting of carotid stenosis in order to improve clinical outcomes is well established. Recent randomised trials have failed to demonstrate improvement of clinical outcomes in VB stroke patients treated with stenting. To our knowledge, these studies did not require the use of embolic protection devices or techniques. This may be due to several factors. Firstly, since the caliber of the stenotic segment of VA is not large enough to safely allow the protection device delivery system to pass through, initial angioplasty without protection is needed. Secondly, the most common segment of VA to become stenotic is its origin, and usually after stenting of this segment, the edge of the stent is protruding into the SCA. When the angle of the VA relative to the SCA is acute, passing the filter capture catheter through this protruded stent is very difficult and dangerous. Methods : We are introducing a VA reversal blood flow technique for prevention of emboli through the VB system in the setting of symptomatic extracranial VA stenosis. In this technique, we used a balloon tip guide catheter in order to transiently occlude the proximal segment of the SCA, causing flow arrest. We then evaluated the presence of blood flow reversal in the VA. Theoretically, this induction of blood flow reversal in the VA can be considered protective because it washes the embolic particles into the distal SCA. Results : Of the 11 cases of VA origin symptomatic stenosis, 4 had desirable VA blood flow reversal after balloon occlusion trial. These patients had successful angioplasty‐stenting of the VA origin using balloon mounted stent without major complications such as ischemic stroke in the posterior circulation territory. Conclusions : This study demonstrates the feasibility of proximal SCA balloon occlusion to cause transient flow reversal in the VA during angioplasty +/‐ stenting of the proximal VA. Future studies are required to determine the effectiveness of this approach in the setting of extracranial VA stenosis due to atherosclerosis, especially at its proximal segment.