Association Between Vertebral Arterial Tortuosity and Aneurysm Growth in Intracranial Vertebral Artery Dissection

Background and purpose: An intracranial vertebral artery dissecting aneurysm (iVADA) increases the risk of future subarachnoid hemorrhage, which is a severe complication with high rebleeding rates and poor outcomes. Identifying potential risk factors associated with iVADA growth is crucial for their effective management.

Methods: This observational study was carried out at a single center and included patients who had been diagnosed with iVADA based on neuroimaging findings. We divided the patients into two groups: with and without iVADA growth. Growth was defined as any enlargement of a dilated region or a morphological change in follow-up imaging. We measured the vertebral artery tortuosity index (VTI) in the contralateral vertebral artery (VA), defined as its actual length divided by its straight length. We investigated the factors associated with iVADA growth.

Results: This study included 124 patients. The median follow-up period was 7 months. We observed iVADA growth in 54 patients (43.5%), who were more likely to be current smokers (33.3% vs. 14.3%, p=0.012) and have a higher VTI (1.14±0.11 [mean±standard deviation] vs. 1.06±0.12, p=0.035) compared with those without iVADA growth. A multivariate analysis revealed that the VTI (adjusted odds ratio=28.490, 95% confidence interval=1.025-792.046, p=0.048) was independently associated with iVADA growth.

Conclusions: This study has identified an independent association between VA tortuosity and iVADA growth.