Posterior Communicating Artery Hypoplasia: A Risk Factor for Vertebral Artery Dissection Causing Subarachnoid Hemorrhage.

OBJECTIVE

Subarachnoid hemorrhage due to vertebral artery dissection is often fatal; however, its anatomical predictors remain unclear. We conducted a retrospective hospital-based case-control study to evaluate whether variations in the posterior communicating artery are associated with the risk of vertebral artery dissection with subarachnoid hemorrhage.

MATERIALS AND METHODS

We obtained data from patients who underwent computed tomography angiography at our hospital between April 2010 and March 2020. Based on the connection between the anterior and posterior circulation of the arterial circle of Willis, the patients were categorized into a separated group (posterior communicating artery hypoplasia) and a connected group (all others). We evaluated the association between the development of posterior communicating artery and subarachnoid hemorrhage due to vertebral artery dissection using multivariate logistic regression analysis.

RESULTS

Thirty-eight patients had subarachnoid hemorrhage due to vertebral artery dissection and 76 were identified as age- and sex-matched controls. In conditional multivariate logistic regression analysis, the separated group showed a significant association with subarachnoid hemorrhage due to vertebral artery dissection, with an adjusted odds ratio of 2.8 (95% confidence interval, 1.2-6.5; P = 0.021).

CONCLUSIONS

The present study demonstrates that posterior communicating artery hypoplasia may be associated with subarachnoid hemorrhage due to vertebral artery dissection. Our results highlight the importance of anatomical variations in the cerebral artery and provide evidence to help develop preventive measures against strokes.