The association between vertebral artery dissection aetiology, morphology and patient factors with the outcome of cerebral infarction

Abstract

Purpose: Vertebral artery dissection (VAD) is a potentially catastrophic phenomenon induced by spontaneous or traumatic mural injury to the vertebral artery1-4. Radiological investigation to exclude acute vertebral artery dissection is increasingly common in the emergency setting. The sequelae of intraluminal haemorrhage - stenosis, dissecting aneurysm or rupture - may manifest as thromboembolic or ischaemic stroke, with significant associated morbidity1. In this retrospective study, we aim to determine if there exists a significant association between the aetiology and radiological features of VAD, with the outcome of cerebral infarction within two Queensland hospital centres. Methods and Materials: Retrospective, non-blinded, cross-sectional study of acute patients with suspected vertebral artery dissection. Patients were identified from two hospital centers in South East Queensland between 2009 and 2013. Acute VAD was confirmed with CT angiography, MR angiography, and/or digital subtraction angiography of the neck and brain. Potential study participants were identified through PACS search using predefined search terms. Confirmed cases of vertebral dissection were identified through manual review of radiology reports and medical charts. Information regarding baseline patient characteristics, dissection aetiology and radiological characteristics were collected utilising a standardised data collection form. Chi-square and Fisher's exact tests were implemented to test the association between infarction and categorical variables. Continuous variables were analysed with a one-way analysis of variance (ANOVA). The study was performed in full compliance with principles of the Declaration of Helsinki and local institutional ethical requirements. Informed consent from participants was not required. All patients were de-identified. Results: 497 patients were identified by the search criteria, of which 90 patients were confirmed to have acute vertebral artery dissection, mean age 50.3 years (+/- 18.7 years). 32.2% patients demonstrated dissections of traumatic aetiology, and 67.8% were spontaneous. 64.4% of patients with acute VAD subsequently developed cerebral infarction. Of the variables investigated, those significantly associated with the outcome of cerebral infarction were aetiology of dissection (p < 0.001) with infarction more frequent in spontaneous dissections; dissection size (p < 0.001), with infarction more common in segmental rather than focal dissections; and the presence of thrombosis (p < 0.001). Dissection location (p = 0.002) was also significantly associated with infarction, being more frequent in dissections of distal (V3, V4), or combined proximal and distal location. Conclusion: Vertebral artery dissection is an increasingly diagnosed pathology with a propensity for serious neurological sequelae. Variables significantly associated with the outcome of cerebral infarction (p < 0.05) were dissection aetiology, location, size and the presence of vertebral/basilar artery thrombosis.<br />