Seyedeh Fatemeh Salimi Ashkezari1, Fernando Mut2, Anne M Robertson3,4, Juan R Cebral2,5. 1. Department of Bioengineering, Volgenau School of Engineering, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA. ssalimia@gmu.edu. 2. Department of Bioengineering, Volgenau School of Engineering, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA. 3. Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA. 4. Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. 5. Department of Mechanical Engineering, George Mason University, Fairfax, VA, USA.
Abstract
PURPOSE: Blebs are known risk factors for intracranial aneurysm (IA) rupture. We analyzed differences between IAs that ruptured with blebs and those that ruptured without developing blebs to identify distinguishing characteristics among them and suggest possible mechanistic implications. METHODS: Using image-based models, 25 hemodynamic and geometric parameters were compared between ruptured IAs with and without blebs (n = 673), stratified by location. Hemodynamic and geometric differences between bifurcation and sidewall aneurysms and for aneurysms at five locations were also analyzed. RESULTS: Ruptured aneurysms harboring blebs were exposed to higher flow conditions than aneurysms that ruptured without developing blebs, and this was consistent across locations. Bifurcation aneurysms were exposed to higher flow conditions than sidewall aneurysms. They had larger maximum wall shear stress (WSS), more concentrated WSS distribution, and larger numbers of critical points than sidewall aneurysms. Additionally, bifurcation aneurysms were larger, more elongated, and had more distorted shapes than sidewall aneurysms. Aneurysm morphology was associated with aneurysm location (p < 0.01). Flow conditions were different between aneurysm locations. CONCLUSION: Aneurysms at different locations are likely to develop into varying morphologies and thus be exposed to diverse flow conditions that may predispose them to follow distinct pathways towards rupture with or without bleb development. This could explain the diverse rupture rates and bleb presence in aneurysms at different locations.
PURPOSE: Blebs are known risk factors for intracranial aneurysm (IA) rupture. We analyzed differences between IAs that ruptured with blebs and those that ruptured without developing blebs to identify distinguishing characteristics among them and suggest possible mechanistic implications. METHODS: Using image-based models, 25 hemodynamic and geometric parameters were compared between ruptured IAs with and without blebs (n = 673), stratified by location. Hemodynamic and geometric differences between bifurcation and sidewall aneurysms and for aneurysms at five locations were also analyzed. RESULTS: Ruptured aneurysms harboring blebs were exposed to higher flow conditions than aneurysms that ruptured without developing blebs, and this was consistent across locations. Bifurcation aneurysms were exposed to higher flow conditions than sidewall aneurysms. They had larger maximum wall shear stress (WSS), more concentrated WSS distribution, and larger numbers of critical points than sidewall aneurysms. Additionally, bifurcation aneurysms were larger, more elongated, and had more distorted shapes than sidewall aneurysms. Aneurysm morphology was associated with aneurysm location (p < 0.01). Flow conditions were different between aneurysm locations. CONCLUSION: Aneurysms at different locations are likely to develop into varying morphologies and thus be exposed to diverse flow conditions that may predispose them to follow distinct pathways towards rupture with or without bleb development. This could explain the diverse rupture rates and bleb presence in aneurysms at different locations.
Authors: Seyedeh Fatemeh Salimi Ashkezari; Fernando Mut; Bong Jae Chung; Anne M Robertson; Juan R Cebral Journal: J Neurointerv Surg Date: 2020-07-17 Impact factor: 5.836
Authors: Seyedeh Fatemeh Salimi Ashkezari; Fernando Mut; Bong Jae Chung; Alexander K Yu; Christopher J Stapleton; Alfred P See; Sepideh Amin-Hanjani; Fady T Charbel; Behnam Rezai Jahromi; Mika Niemelä; Juhana Frösen; Spandan Maiti; Anne M Robertson; Juan R Cebral Journal: J Neurointerv Surg Date: 2020-10-05 Impact factor: 5.836