Stagnation and complex flow in ruptured cerebral aneurysms: a possible association with hemostatic pattern

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Pathology

Background:

• Cerebral aneurysms are abnormal blood vessel bulges that can rupture, leading to life-threatening hemorrhage.
• Histopathological examination of ruptured aneurysms reveals varying hemostatic patterns based on clot location.
• Understanding these patterns is crucial for predicting aneurysm behavior and treatment strategies.

Purpose of the Study:

• To investigate the hemodynamic features associated with different hemostatic patterns in ruptured cerebral aneurysms.
• To determine if computational fluid dynamics (CFD) can differentiate between inside-pattern and outside-pattern aneurysms.

Main Methods:

• Twenty-six ruptured middle cerebral artery aneurysms were analyzed using 3D CT angiography.
• Histopathological examination assessed hemostatic patterns at rupture sites.
• CFD analysis calculated hemodynamic parameters like wall shear stress and invariant Q.

Main Results:

• Thirteen aneurysms showed an inside pattern, nine an outside pattern, and four were classified as other.
• Inside-pattern aneurysms were associated with significantly lower dome volume, gradient oscillatory number, and invariant Q.
• Higher aneurysm formation indicator values were also linked to inside-pattern aneurysms.

Conclusions:

• Inside-pattern cerebral aneurysms appear to have less complex blood flow and reduced flow stagnation.
• CFD analysis shows promise as a tool for characterizing hemostatic patterns in ruptured cerebral aneurysms.
• These findings may aid in understanding aneurysm rupture mechanisms and guiding clinical decisions.