Natural History of Unruptured Vertebral Basilar Artery Dissection: Temporal Changes in Imaging Findings and Contributory Factors

Abstract

\n PurposeTo investigate temporal changes in imaging findings of conservatively treated unruptured vertebral basilar artery dissection and its contributing factors.MethodsFifty-three patients who underwent conservative treatment for 64 cases of vertebral basilar artery dissection diagnosed between January 2006 and March 2019 and follow-up of at least 12 months after onset were retrospectively investigated. Statistical analyses of age, sex, medical history, pattern of onset, lesion site, imaging findings and changes over time, regular medication, and outcomes were performed. ResultsChanges in the vascular morphology of the lesion site during the follow-up period were observed in only 23 (43%) patients (median time until change: 19 days). Univariate analysis of factors contributing to morphological changes at the dissection site showed that changes were significantly more likely in younger patients (p = 0.011). Patients taking antiplatelet drugs had a significantly greater rate of deterioration at the dissection site (p = 0.028) than others. On multivariate analysis, age was an independent factor contributing to changes at the dissection site, and taking antiplatelet drugs, particularly clopidogrel, was an independent factor contributing to deterioration. No patient developed intracranial hemorrhage, cerebral infarction, or worsening of neurological symptoms during follow-up.ConclusionsMorphological changes at the dissection site are more likely in younger patients with unruptured vertebral basilar artery dissection and those taking antiplatelet drugs. However, chances of intracranial hemorrhage, cerebral infarction, or worsening of neurological symptoms during conservative therapy are low. Therefore, unruptured vertebral basilar artery dissection may be considered a benign condition.