title: High WSS or low WSS? Complex interactions of hemodynamics with intracranial aneurysm initiation, growth, and rupture: toward a unifying hypothesis.
abstract: Increasing detection of unruptured intracranial aneurysms, catastrophic outcomes from subarachnoid hemorrhage, and risks and cost of treatment necessitate defining objective predictive parameters of aneurysm rupture risk. Image-based computational fluid dynamics models have suggested associations between hemodynamics and intracranial aneurysm rupture, albeit with conflicting findings regarding wall shear stress. We propose that the "high-versus-low wall shear stress" controversy is a manifestation of the complexity of aneurysm pathophysiology, and both high and low wall shear stress can drive intracranial aneurysm growth and rupture. Low wall shear stress and high oscillatory shear index trigger an inflammatory-cell-mediated pathway, which could be associated with the growth and rupture of large, atherosclerotic aneurysm phenotypes, while high wall shear stress combined with a positive wall shear stress gradient trigger a mural-cell-mediated pathway, which could be associated with the growth and rupture of small or secondary bleb aneurysm phenotypes. This hypothesis correlates disparate intracranial aneurysm pathophysiology with the results of computational fluid dynamics in search of more reliable risk predictors.
authors.affiliation: From the Toshiba Stroke and Vascular Research Center (H.M., V.M.T., J.X., A.S.)Departments of Mechanical and Aerospace Engineering (H.M.)Neurosurgery (H.M., J.X., A.S.)Biomedical Engineering (H.M., V.M.T.), University at Buffalo, State University of New York, Buffalo, New York. huimeng@buffalo.edu.
authors.forename: H
authors.initials: H
authors.lastname: Meng
authors.affiliation: From the Toshiba Stroke and Vascular Research Center (H.M., V.M.T., J.X., A.S.)Biomedical Engineering (H.M., V.M.T.), University at Buffalo, State University of New York, Buffalo, New York.
authors.forename: V M
authors.initials: VM
authors.lastname: Tutino
authors.affiliation: From the Toshiba Stroke and Vascular Research Center (H.M., V.M.T., J.X., A.S.)Neurosurgery (H.M., J.X., A.S.).
authors.forename: J
authors.initials: J
authors.lastname: Xiang
authors.affiliation: From the Toshiba Stroke and Vascular Research Center (H.M., V.M.T., J.X., A.S.)Neurosurgery (H.M., J.X., A.S.).
authors.forename: A
authors.initials: A
authors.lastname: Siddiqui
mesh_terms: D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000792:Angiography; D000818:Animals; D001783:Blood Flow Velocity; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008955:Models, Cardiovascular; D008959:Models, Neurological; D033081:Shear Strength; D013314:Stress, Mechanical