Analysis of the clinical characteristics of V4 segment steal blood in the vertebral artery

Objective To explore the clinical characteristics of unilateral vertebral artery V4 segment occlusive lesions(severe stenosis or occlusion),where the contralateral vertebral artery can be compensated through blood flow and reverse supplytothe posterior inferior cerebellarartery(PICA).Methods This study is a retrospective case series of 66 patients with V4 segment occlusive lesions of unilateral vertebral artery diagnosed and treated from June 2020 to October 2022.Patient data were retrospectively collected,and their hemodynamic characteristics and imaging data were analyzed.Results Of the 66 cases,11 patients(16.7%)with V4 segment occlusive disease showed the blood flow of the vertebral artery on the opposite side of the lesion on the digital subtraction angiography(DSA),which can be reversely stolen to the posterior inferior cerebellar artery of the diseased side through the confluence point of the vertebrobasilar artery through the distal end of the ipsilateral vertebral artery V4.Owing to the lack of literature on this pathway and based on the characteristics of previous definitions of subclavian artery steal and carotid artery steal,we referred to this pathway as the vertebral artery V4 segment steal.In 6 patients(9.1%)。