Article Figures & Data
Figures
- Fig 1.
Examples of aneurysm growth (A and B) and rupture (C and D) correlated with high wall shear stress and low WSS. A, In a serial study consisting of a baseline and 4 follow-ups, Acevedo-Bolton et al10 found that the maximal growth region (1) of a giant basilar fusiform intracranial aneurysm consistently had the lowest WSS. B, Sugiyama et al13 reported 2 adjacent growing aneurysms, with different hemodynamic characteristics and growing patterns in 1 patient. The proximal growing aneurysm (2) was subjected to local high flow in the growing lobe, while the distal aneurysm (3) was associated with low and oscillatory WSS in the entire aneurysm sac. C, From multivariate statistical analysis of 119 aneurysms, Xiang et al5 found that intracranial aneurysm rupture could be predicted by low WSS and high oscillatory shear index. D, Castro et al11 found, from analysis of 26 aneurysms, that intracranial aneurysm rupture was correlated with high maximum WSS. Images were adapted with permission from the cited references.
- Fig 2.
How hemodynamics plays into intracranial aneurysm dynamics. A, Three-way relationship of aneurysmal geometry, flow, and pathobiology. Flow exerts mechanical forces on the vessel wall, eliciting cell-mediated biologic pathways. Sustained changes in flow (thus WSS and pressure) lead to remodeling of the wall, resulting in aneurysm geometry change. In turn, geometry determines the flow, which could drive further biologic processes. B, The balance between growth/repair and degradation/destruction results in aneurysm stability. Aberrant hemodynamics disrupts the balance and amplifies degradation and destruction mechanisms, leading to enlargement and rupture of aneurysm.
- Fig 3.
Heterogeneity of saccular aneurysms as a spectrum from type I (A) to type II (D) with various intermediate or combination types in between (B and C). A, A small thin-walled, entirely translucent aneurysm (type I). B, A mostly thin-walled aneurysm with some thicker-walled patches. C, A mostly thick-walled aneurysm with a few thin-walled patches. D, An aneurysm with an entirely thick, atherosclerotic wall (Type II). Images adapted with permission from Kadasi et al 2012.50
- Fig 4.
A unified role of high and low WSS in aneurysm initiation, growth, and rupture.
- Fig 5.
Two hypothesized, independent, hemodynamic-biologic pathways that drive intracranial aneurysm growth and rupture (A) and the proposed relationship between them and the spectrum of intracranial aneurysm phenotypes (B).
Tables
Vascular responses to aberrant WSS conditions reported in literature
Pathobiologic Responses to High WSS and Positive WSS Gradienta Pathobiologic Responses to Low WSS and High OSIb EC damage24,45 Proinflammatory ECs that are “leaky” and “sticky”21,62 EC turnover25,72 Increased ROS62 MMP production by mural cells25 Increased inflammatory cell infiltration70 ECM degradation36 MMP production by macrophages61 Medial thinning36 SMC proliferation and migration63 Mural cell apoptosis25 Thrombus formation23,63
Jump to section
Related Articles
Cited By...
- Statin treatment for unruptured intracranial aneurysms study: a study protocol for a double-blind, placebo-controlled trial
- Hemodynamics in aneurysm blebs with different wall characteristics
- Hemodynamic conditions that favor bleb formation in cerebral aneurysms
- A Hemodynamic Mechanism Correlating with the Initiation of MCA Bifurcation Aneurysms
- Effects of size and elasticity on the relation between flow velocity and wall shear stress in side-wall aneurysms: A lattice Boltzmann-based computer simulation study
- Comparing Morphology and Hemodynamics of Stable-versus-Growing and Grown Intracranial Aneurysms
- Novel Models for Identification of the Ruptured Aneurysm in Patients with Subarachnoid Hemorrhage with Multiple Aneurysms
- Genetic correlates of wall shear stress in a patient-specific 3D-printed cerebral aneurysm model
- Differences in hemodynamic characteristics under high packing density between the porous media model and finite element analysis in computational fluid dynamics of intracranial aneurysm virtual treatment
- Local Hemodynamic Conditions Associated with Focal Changes in the Intracranial Aneurysm Wall
- Impact of the global outflow angle on recanalization after endovascular treatment of middle cerebral artery bifurcation aneurysms
- Low Wall Shear Stress Is Associated with Local Aneurysm Wall Enhancement on High-Resolution MR Vessel Wall Imaging
- Critical role of angiographic acquisition modality and reconstruction on morphometric and haemodynamic analysis of intracranial aneurysms
- Shared and Distinct Rupture Discriminants of Small and Large Intracranial Aneurysms
- Does the DSA reconstruction kernel affect hemodynamic predictions in intracranial aneurysms? An analysis of geometry and blood flow variations
- A patient-specific intracranial aneurysm model with endothelial lining: a novel in vitro approach to bridge the gap between biology and flow dynamics
- Presence of Anterior Communicating Artery Aneurysm Is Associated With Age, Bifurcation Angle, and Vessel Diameter
- Differences in Morphologic and Hemodynamic Characteristics for "PHASES-Based" Intracranial Aneurysm Locations
- Flow Diversion with Low-Profile Braided Stents for the Treatment of Very Small or Uncoilable Intracranial Aneurysms at or Distal to the Circle of Willis
- Angioarchitectures and Hemodynamic Characteristics of Posterior Communicating Artery Aneurysms and Their Association with Rupture Status
- Computational fluid dynamics of cerebral aneurysm coiling using high-resolution and high-energy synchrotron X-ray microtomography: comparison with the homogeneous porous medium approach
- Differences in Hemodynamics and Rupture Rate of Aneurysms at the Bifurcation of the Basilar and Internal Carotid Arteries
- Flow Conditions in the Intracranial Aneurysm Lumen Are Associated with Inflammation and Degenerative Changes of the Aneurysm Wall
- Assessment of intracranial aneurysm rupture based on morphology parameters and anatomical locations
- Thinner Regions of Intracranial Aneurysm Wall Correlate with Regions of Higher Wall Shear Stress: A 7T MRI Study
- Hemodynamic characteristics of large unruptured internal carotid artery aneurysms prior to rupture: a case control study
- Hemodynamic-morphological discriminant models for intracranial aneurysm rupture remain stable with increasing sample size
- Hemodynamic Differences in Intracranial Aneurysms before and after Rupture
- Wall Mechanical Properties and Hemodynamics of Unruptured Intracranial Aneurysms
- Narrowing the Expertise Gap for Predicting Intracranial Aneurysm Hemodynamics: Impact of Solver Numerics versus Mesh and Time-Step Resolution
- The Computational Fluid Dynamics Rupture Challenge 2013--Phase I: Prediction of Rupture Status in Intracranial Aneurysms
- CFD: Computational Fluid Dynamics or Confounding Factor Dissemination? The Role of Hemodynamics in Intracranial Aneurysm Rupture Risk Assessment
- Generalized versus Patient-Specific Inflow Boundary Conditions in Computational Fluid Dynamics Simulations of Cerebral Aneurysmal Hemodynamics