Mechanical Thrombectomy for Hyperacute Vertebrobasilar Ischemic Stroke via Nondominant Vertebral Artery : Clinical Experience and Considerations

Abstract

Objective: The dominant vertebral artery (VA) approach is primarily considered in mechanical thrombectomy (MT) for acute occlusion of the vertebrobasilar (VB) artery. As accessing the dominant artery is sometimes difficult, we present our experience treating acute VB stroke via a nondominant VA approach through a comparison with the dominant VA approach.

Methods: Among 2785 patients diagnosed with hyperacute ischemic stroke between January 2014 and December 2022, 50 patients with VB ischemic stroke underwent recanalization therapy through either dominant, nondominant, or bilateral VA approach. We evaluated patient characteristics and clinical course, highlighting the pros and cons of the access routes.

Results: The patients with hyperacute VB ischemic stroke were predominantly male (72%), with a mean age of 68.12 years and an initial National Institutes of Health Stroke Scale score mean of 17.1. Large-artery atherosclerosis (48%) and cardioembolism (36%) were the main etiologic factors in the Trial of Org 10172 in Acute Stroke Treatment classification. After thrombectomy, 45 cases (90%) had final modified thrombolysis in cerebral infarction score of 2b or higher. In summary, 41 patients were treated through the dominant VA, and eight patients underwent the nondominant VA approach. However, there was no statistically significant difference in functional outcome or mortality between the two approaches.

Conclusion: In MT for VB occlusions, nondominant VA approach may be an option in situations when the vessel is accessible, stable, or less risky, as recanalization can be achieved without rescue balloon angioplasty and/or stenting.

Keywords: Basilar artery; Ischemic stroke; Thrombectomy; Vertebral artery.

Fig. 1.

Flow diagram of VA access choice and recanalization modalities. ‘Difficult access to VB’ is defined as a case in which the approach was disturbed during either symptomatic main lesion navigation (near occlusion of VA ostium, VA segment 4 around PICA ostium, or subclavian artery) or involved device access failure. VB : vertebrobasilar, VA : vertebral artery, MT : mechanical thrombectomy, RAS : rescue angioplasty and/or stent insertion.

Fig. 2.

Nondominant vertebral artery (VA) access examples. A : Bilateral VA roadmap image. The thick arrow shows near occlusion of the VA ostium in leftmost image, and the thin arrow shows mid-basilar artery occlusion in the preprocedural angiogram in center image. The rightmost image shows recanalization by mechanical thrombectomy through the nondominant VA route. B : Arrow shows the thrombus as a filling defect in leftmost image. The aspiration catheter could not be advanced to the lesion site, so the contralateral nondominant VA approach was used in center image. Postprocedural image showed removed thrombus in rightmost image. C : The subclavian artery was completely occluded in the volume rendering image (arrow shows the occlusion).