Subarachnoid Hemorrhage from Ruptured Aneurysm in the Middle Cerebral Artery and Anterior Cerebral Artery Trunk: A Single-Center Study

Objective: Ruptured anterior cerebral artery (ACA) trunk aneurysms and middle cerebral artery (MCA) trunk aneurysms are rare, and little is known about them. This study was conducted to determine the difference between these and other types of aneurysms.Methods: We performed a retrospective review of patients diagnosed with subarachnoid hemorrhage over an 8-year period at a single institution. We analyzed the characteristics, clinical factors, and radiological components of aneurysms at the trunk portion of A-1 and M-1. Descriptive analysis and univariate analysis for factors were performed to determine the differences of ACA A-1 portion trunk and MCA M-1 portion trunk aneurysms from other ACA and MCA aneurysms, respectively.Results: Univariate logistic regression modeling showed that trunk aneurysms in MCA M-1 had a smaller dome size (p=0.026) and dome/neck ratio (p=0.048) than other MCA aneurysms. Likewise, through univariate logistic regression modeling, the ACA group showed differences in dome size including age (p=0.001) as well as dome size (p=0.038) and dome neck ratio (p=0.041) in the A1 region.Conclusion: MCA M-1 and ACA A-1 trunk aneurysms are likely to have several different characteristics such as small in size and a lower dome/neck ratio. Also, due to their close locations to the perforator arteries, there is a high possibility of perforator artery injury when treating these aneurysms. Thus, careful attention is required when setting the treatment methods, and further studies about these aneurysms are needed.