Middle Cerebral Artery Bifurcation Geometry and Aneurysm Formation: A Propensity Score-Matched 3D Rotational...

Area of Science:

• Neurosurgery
• Vascular Neurology
• Medical Imaging

Background:

• The middle cerebral artery (MCA) bifurcation is a frequent location for intracranial aneurysms.
• Understanding the geometric factors influencing aneurysm formation and rupture is crucial for clinical management.

Purpose of the Study:

• To investigate the association between MCA bifurcation geometry and the presence of aneurysms.
• To explore the relationship between aneurysm rupture and aneurysm size, as well as bifurcation geometry.

Main Methods:

• A retrospective, propensity score-matched case-control study involving 133 MCA bifurcation aneurysms and 266 controls.
• Quantification of bifurcation and aneurysm sac geometry using 3D rotational digital subtraction angiography (DSA).
• Statistical analysis using generalized estimating equation (GEE) logistic regression and receiver operating characteristic-area under the curve (ROC-AUC).

Main Results:

• Wider MCA bifurcation opening angles and more asymmetric branch angles were independently associated with aneurysm presence.
• A larger opening angle (per 5° increase) correlated with approximately 40% higher odds of aneurysm presence.
• Aneurysm rupture was not linked to bifurcation geometry but was associated with larger aneurysm size.

Conclusions:

• MCA bifurcation aneurysm presence is associated with wider, more asymmetric geometric features.
• Aneurysm rupture risk appears more strongly correlated with aneurysm sac size than with the geometry of the MCA bifurcation itself.