Predicting Morphological Changes to Vessel Walls Adjacent to Unruptured Cerebral Aneurysms Using Computational Fluid...

Area of Science:

• Neurosurgery
• Medical Imaging
• Biomechanical Engineering

Background:

• Unruptured middle cerebral artery aneurysms pose a risk of rupture.
• Accurate assessment of perianeurysmal vessel wall integrity is crucial for treatment planning.
• Computed tomography angiography (CTA) visualizes the vessel lumen but may miss subtle wall abnormalities.

Purpose of the Study:

• To compare intraoperative findings with preoperative computed tomography angiography (CTA) and computational fluid dynamics (CFD) analysis.
• To evaluate the utility of the parent artery radiation sign (PARS) in CFD analysis for detecting vessel wall thinning or microaneurysms.
• To assess the correlation between CFD-identified PARS and intraoperative surgical findings.

Main Methods:

• Retrospective analysis of 38 patients with unruptured middle cerebral artery aneurysms treated surgically.
• Preoperative CTA and CFD analysis were performed to identify the parent artery radiation sign (PARS).
• PARS was defined by specific criteria including streamline impingement, wall shear stress vector radiation, and increased wall pressure.

Main Results:

• In 9 cases with identified PARS, CTA showed no morphological abnormalities.
• Intraoperative findings revealed parent artery wall thinning in 1 case and microaneurysm formation in 3 cases, discrepancies not seen on CTA.
• All 9 patients with PARS underwent additional surgical intervention at the identified site.

Conclusions:

• The parent artery radiation sign (PARS) in CFD analysis may indicate subtle vessel wall thinning or microaneurysms missed by CTA.
• Endovascular therapies relying solely on lumen visualization may overlook these perianeurysmal abnormalities.
• CFD analysis highlights the importance of direct intraoperative confirmation of vessel wall findings around aneurysms.