Estimating the hemodynamic impact of interventional treatments of aneurysms: numerical simulation with experimental validation: technical case report.
OBJECTIVE
The goal of this study was to use phase-contrast magnetic resonance imaging and computational fluid dynamics to estimate the hemodynamic outcome that might result from different interventional options for treating a patient with a giant fusiform aneurysm.


METHODS
We followed a group of patients with giant intracranial aneurysms who have no clear surgical options. One patient demonstrated dramatic aneurysm growth and was selected for further analysis. The aneurysm geometry and input and output flow conditions were measured with contrast-enhanced magnetic resonance angiography and phase-contrast magnetic resonance imaging. The data was imported into a computational fluid dynamics program and the velocity fields and wall shear stress distributions were calculated for the presenting physiological condition and for cases in which the opposing vertebral arteries were either occluded or opened. These models were validated with in vitro flow experiments using a geometrically exact silicone flow phantom.


RESULTS
Simulation indicated that altering the flow ratio in the two vertebrals would deflect the main blood jet into the aneurysm belly, and that this would likely reduce the extent of the region of low wall shear stress in the growth zone.


CONCLUSIONS
Computational fluid dynamics flow simulations in a complex patient-specific aneurysm geometry were validated by in vivo and in vitro phase-contrast magnetic resonance imaging, and were shown to be useful in modeling the likely hemodynamic impact of interventional treatment of the aneurysm.
Acevedo-Bolton
Gabriel
G
Department of Radiology, Veterans Affairs Medical Center San Francisco, San Francisco, California 94121, USA. gabriel.acevedo-bolton@med.va.gov
Jou
Liang-Der
LD
Dispensa
Bradley P
BP
Lawton
Michael T
MT
Higashida
Randall T
RT
Martin
Alastair J
AJ
Young
William L
WL
Saloner
David
D
D000368:Aged; D001488:Basilar Artery / Q000473:pathology* / Q000503:physiopathology*; D001794:Blood Pressure; D002560:Cerebrovascular Circulation; D002985:Clinical Protocols / Q000592:standards; D003198:Computer Simulation; D003661:Decision Support Techniques; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008953:Models, Anatomic; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D013314:Stress, Mechanical; D014656:Vascular Surgical Procedures / Q000295:instrumentation / Q000379:methods; D014711:Vertebral Artery / Q000473:pathology