Correlation between lumenal geometry changes and hemodynamics in fusiform intracranial aneurysms

Area of Science:

• Cerebrovascular research
• Medical imaging and computational modeling
• Fluid dynamics in biological systems

Background:

• Hemodynamic forces are implicated in aneurysm rupture, but their role in aneurysm growth is not fully understood.
• Investigating hemodynamic descriptors is crucial for predicting the growth of fusiform basilar artery aneurysms.
• This study aims to identify specific hemodynamic variables associated with aneurysm expansion.

Observation:

• Two patients with similar-sized fusiform basilar artery aneurysms were monitored over two years.
• MR angiography and velocimetry were used to assess lumenal geometry and flow rates.
• Computational fluid dynamic simulations were employed to calculate hemodynamic descriptors and compare them with aneurysm growth patterns.

Findings:

• One aneurysm exhibited significant growth (approx. 3 mm/year) at the inferior aspect, correlating with very low wall shear stress (<0.1N/m²).
• The other similar-sized aneurysm remained unchanged, despite similar general flow patterns over time.
• Histograms of wall shear stress differed significantly between the growing and stable aneurysms.

Implications:

• Hemodynamic descriptors, particularly wall shear stress, show potential for correlating with regional aneurysm lumen morphology on a patient-specific basis.
• This patient-specific approach can facilitate future longitudinal studies to elucidate mechanisms driving aneurysm growth.
• Understanding these mechanisms is vital for developing targeted treatments and improving aneurysm management strategies.