J R Cebral1, F Detmer2, B J Chung2, J Choque-Velasquez3, B Rezai3, H Lehto3, R Tulamo3,4, J Hernesniemi3, M Niemela3, A Yu5, R Williamson5, K Aziz5, S Shakur6, S Amin-Hanjani6, F Charbel6, Y Tobe7, A Robertson7, J Frösen8. 1. From the Department of Bioengineering (J.R.C., F.D., B.J.C.), Volgenau School of Engineering, George Mason University, Fairfax, Virginia jcebral@gmu.edu. 2. From the Department of Bioengineering (J.R.C., F.D., B.J.C.), Volgenau School of Engineering, George Mason University, Fairfax, Virginia. 3. Neurosurgery Research Group (J.C.-V., B.R., H.L., R.T., J.H., M.N.), Biomedicum Helsinki and Helsinki University Central Hospital, Helsinki, Finland. 4. Department of Vascular Surgery (R.T.), Helsinki University Central Hospital, Helsinki, Finland. 5. Department of Neurosurgery (A.Y., R.W., K.A.), Allegheny General Hospital, Pittsburgh, Pennsylvania. 6. Department of Neurosurgery (S.S., S.A.-H., F.C.), University of Illinois at Chicago, Chicago, Illinois. 7. Mechanical Engineering and Materials Science and Department of Bioengineering (Y.T., A.R.), Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania. 8. Hemorrhagic Brain Pathology Research Group (J.F.), Neurocenter, Kuopio University Hospital, Kuopio, Finland.
Abstract
BACKGROUND AND PURPOSE: Aneurysm hemodynamics has been associated with wall histology and inflammation. We investigated associations between local hemodynamics and focal wall changes visible intraoperatively. MATERIALS AND METHODS: Computational fluid dynamics models were constructed from 3D images of 65 aneurysms treated surgically. Aneurysm regions with different visual appearances were identified in intraoperative videos: 1) "atherosclerotic" (yellow), 2) "hyperplastic" (white), 3) "thin" (red), 4) rupture site, and 5) "normal" (similar to parent artery), They were marked on 3D reconstructions. Regional hemodynamics was characterized by the following: wall shear stress, oscillatory shear index, relative residence time, wall shear stress gradient and divergence, gradient oscillatory number, and dynamic pressure; these were compared using the Mann-Whitney test. RESULTS: Hyperplastic regions had lower average wall shear stress (P = .005) and pressure (P = .009) than normal regions. Flow conditions in atherosclerotic and hyperplastic regions were similar but had higher average relative residence time (P = .03) and oscillatory shear index (P = .04) than thin regions. Hyperplastic regions also had a higher average gradient oscillatory number (P = .002) than thin regions. Thin regions had lower average relative residence time (P < .001), oscillatory shear index (P = .006), and gradient oscillatory number (P < .001) than normal regions, and higher average wall shear stress (P = .006) and pressure (P = .009) than hyperplastic regions. Thin regions tended to be aligned with the flow stream, while atherosclerotic and hyperplastic regions tended to be aligned with recirculation zones. CONCLUSIONS: Local hemodynamics is associated with visible focal wall changes. Slow swirling flow with low and oscillatory wall shear stress was associated with atherosclerotic and hyperplastic changes. High flow conditions prevalent in regions near the flow impingement site characterized by higher and less oscillatory wall shear stress were associated with local "thinning" of the wall.
BACKGROUND AND PURPOSE:Aneurysm hemodynamics has been associated with wall histology and inflammation. We investigated associations between local hemodynamics and focal wall changes visible intraoperatively. MATERIALS AND METHODS: Computational fluid dynamics models were constructed from 3D images of 65 aneurysms treated surgically. Aneurysm regions with different visual appearances were identified in intraoperative videos: 1) "atherosclerotic" (yellow), 2) "hyperplastic" (white), 3) "thin" (red), 4) rupture site, and 5) "normal" (similar to parent artery), They were marked on 3D reconstructions. Regional hemodynamics was characterized by the following: wall shear stress, oscillatory shear index, relative residence time, wall shear stress gradient and divergence, gradient oscillatory number, and dynamic pressure; these were compared using the Mann-Whitney test. RESULTS: Hyperplastic regions had lower average wall shear stress (P = .005) and pressure (P = .009) than normal regions. Flow conditions in atherosclerotic and hyperplastic regions were similar but had higher average relative residence time (P = .03) and oscillatory shear index (P = .04) than thin regions. Hyperplastic regions also had a higher average gradient oscillatory number (P = .002) than thin regions. Thin regions had lower average relative residence time (P < .001), oscillatory shear index (P = .006), and gradient oscillatory number (P < .001) than normal regions, and higher average wall shear stress (P = .006) and pressure (P = .009) than hyperplastic regions. Thin regions tended to be aligned with the flow stream, while atherosclerotic and hyperplastic regions tended to be aligned with recirculation zones. CONCLUSIONS: Local hemodynamics is associated with visible focal wall changes. Slow swirling flow with low and oscillatory wall shear stress was associated with atherosclerotic and hyperplastic changes. High flow conditions prevalent in regions near the flow impingement site characterized by higher and less oscillatory wall shear stress were associated with local "thinning" of the wall.
Authors: Juhana Frösen; Riikka Tulamo; Anders Paetau; Elisa Laaksamo; Miikka Korja; Aki Laakso; Mika Niemelä; Juha Hernesniemi Journal: Acta Neuropathol Date: 2012-01-17 Impact factor: 17.088
Authors: Juan R Cebral; Marcelo A Castro; Sunil Appanaboyina; Christopher M Putman; Daniel Millan; Alejandro F Frangi Journal: IEEE Trans Med Imaging Date: 2005-04 Impact factor: 10.048
Authors: J Cebral; E Ollikainen; B J Chung; F Mut; V Sippola; B R Jahromi; R Tulamo; J Hernesniemi; M Niemelä; A Robertson; J Frösen Journal: AJNR Am J Neuroradiol Date: 2016-09-29 Impact factor: 3.825
Authors: Juan R Cebral; Fernando Mut; Piyusha Gade; Fangzhou Cheng; Yasutaka Tobe; Juhana Frosen; Anne M Robertson Journal: Int J Numer Method Biomed Eng Date: 2018-08-21 Impact factor: 2.747
Authors: L M Gottwald; J Töger; K Markenroth Bloch; E S Peper; B F Coolen; G J Strijkers; P van Ooij; A J Nederveen Journal: AJNR Am J Neuroradiol Date: 2020-06-25 Impact factor: 3.825
Authors: Ashrita Raghuram; Alberto Varon; Sebastian Sanchez; Daizo Ishii; Chaorong Wu; Vincent A Magnotta; David M Hasan; Timothy R Koscik; Edgar A Samaniego Journal: Stroke Vasc Interv Neurol Date: 2022-05-08
Authors: Katharina A M Hackenberg; Hamidreza Rajabzadeh-Oghaz; Rita Dreier; Bruce A Buchholz; Ali Navid; David M Rocke; Amr Abdulazim; Daniel Hänggi; Adnan Siddiqui; R Loch Macdonald; Hui Meng; Nima Etminan Journal: Stroke Date: 2020-03-20 Impact factor: 7.914
Authors: Seyedeh Fatemeh Salimi Ashkezari; Fernando Mut; Bong Jae Chung; Anne M Robertson; Juhana Frösen; Juan R Cebral Journal: Int J Numer Method Biomed Eng Date: 2020-11-25 Impact factor: 2.747