In acute ischemic stroke due to tandem occlusion, the emergent stenting has recently become an endovascular treatment option combining with mechanical thrombectomy to achieve recanalization. However, the data on the beneficial endovascular management of tandem occlusion in two circulations is still limited. The purpose of our study was to compare the improvement of clinical outcome between two circulations after emergent stenting at 3 months.

The posterior circulation (about 20 - 25%) is less frequent than the anterior one in the acute ischemic stroke, but high mortality and morbidity in the acute vertebrobasilar thrombosis even successful recanalization are revealed. Besides, tandem occlusion is one of the complex lesions in large vessel occlusions relating to the poor outcome, particularly in the posterior circulation. Recent studies have suggested that emergent stenting could be used as an additional treatment to achieve permanent recanalization together with mechanical thrombectomy in the intracranial segments. Permanent recanalization is one of the most important factors that impact patient outcomes after acute ischemic stroke. However, although there are various approaches for this lesion, the comparision of the effectiveness in the two circulations remains unclear. Thus, the aims of our study were to compare baseline characteristics and clinical outcome of tandem occlusions between anterior and posterior circulation after emergent stenting in extracranial arteries.

Inclusion Criteria:

• Age > 18 years old
• Premorbid mRS < 2
• NIHSS > 5
• ASPECTS ≥ 5 or pc-ASPECTS ≥ 5

Exclusion Criteria:

• Onset to treatment time > 24 hours
• Loss to follow up after discharge