Differences in Morphologic and Hemodynamic Characteristics for "PHASES-Based" Intracranial Aneurysm Locations

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Radiology

Background:

• Unruptured intracranial aneurysms (UIAs) show varying rupture risks based on location.
• Understanding rupture-prone characteristics is crucial for UIA management.
• Morphological and hemodynamic factors are implicated in aneurysm rupture.

Purpose of the Study:

• To investigate differences in rupture-prone characteristics among intracranial aneurysms at distinct anatomical locations.
• To compare morphological and hemodynamic factors in aneurysms of the internal carotid artery (ICA), middle cerebral artery (MCA), and anterior/posterior circulation.

Main Methods:

• Retrospective analysis of 311 unruptured aneurysms.
• Classification into three location groups: ICA, MCA, and anterior/posterior communicating and posterior circulation arteries.
• Comparison of morphological (e.g., size ratio) and hemodynamic (e.g., wall shear stress, pressure loss) characteristics based on the PHASES study criteria.

Main Results:

• Significant differences in size ratio, low wall shear stress area, and pressure loss coefficient were observed between aneurysm location groups.
• ICA aneurysms demonstrated lower size ratios, lower wall shear stress areas, and lower pressure loss coefficients compared to MCA and other posterior circulation aneurysms.
• No significant differences in morphologic or hemodynamic characteristics were found between MCA aneurysms and the anterior/posterior circulation group.

Conclusions:

• Internal carotid artery aneurysms may possess inherently less rupture-prone morphologic and hemodynamic profiles.
• These findings may contribute to the observed lower rupture propensity of intracranial aneurysms in the ICA location.
• Further research into location-specific UIA characteristics is warranted.