Abstract 169: Using Thyrocervical Trunk Collaterals For Bailout Access of Vertebral Artery with Occluded Atherosclerotic Origin

Introduction/Purpose Rarely, Vertebral Artery (VA) origin atherosclerotic occlusion may need to be accessed. It can be challenging if occlusion cannot be traversed anterograde. We present two cases of successful retrograde access of vertebral arteries through collaterals from ascending cervical arteries. Materials/methods Retrospective chart review of two endovascular cases from a list of retrograde access of vertebral arteries from ascending cervical arteries was performed. Results (1) A 58‐year‐old male who presented with recurrent posterior circulation embolic events in setting of left VA occlusion (failed maximal medical therapy); presented with sudden onset left‐sided weakness ataxia and facial numbness. Patient was deemed not be a thrombolytic candidate. Imaging demonstrated acute Right PCA territory stroke. Contralateral vertebral artery was non‐dominant with hypoplastic V4. Due to recurrent embolic events attributed to stump embolization from occluded left vertebral artery despite medical management, we decided to embolize left vertebral artery. Cerebral angiogram demonstrated complete occlusion of left VA with collateralization from left thyrocervical trunk. We accessed left VA from thyrocervical trunk/ascending cervical collaterals and occluded left VA below major collaterals anastomosis. Coil embolization of left VA above scattered filling defect 1.5 cm above left VA origin prevented further embolic events. (2) A 46‐year‐old male who presented with slurred speech, monocular right eye blurred vision, right facial droop and bilateral upper extremity ataxia. Post thrombolytic administration, patient failed maximal medical management. Due to recurrent posterior circulation strokes, urgent cerebral angiogram was attempted which confirmed proximal left VA and distal basilar artery occlusions, right VA terminating in PICA; retrograde filling and reconstitution of VA from central and deep cervical artery off left subclavian artery. Combined transradial and transfemoral access was acquired. Microcatheterization was attempted into thyrocervical trunk/ascending cervical branches reconstituting in left VA after which microcatheter was advanced into left VA which was advanced retrograde into left subclavian. From left transfemoral access site, Sophia catheter was used to access proximal left VA ensuring microcatheter and Sophia abut each other (image 1). Balloon angioplasty was successfully completed. This was followed by suction thrombectomy of left VA and distal basilar artery ending in stenting proximal left VA. Conclusion In patients with abnormal and challenging VA anatomy , thyrocervical trunk collaterals can serve as alternative pathways to access posterior circulation. image