Linkai Jing1, Jingru Zhong2, Jian Liu1, Xinjian Yang1, Nikhil Paliwal3, Hui Meng4, Shengzhang Wang5, Ying Zhang6. 1. Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. 2. Department of Biomedical Engineering, Capital Medical University, Beijing, China. 3. Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA; Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA. 4. Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA; Toshiba Stroke and Vascular Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA; Department of Neurosurgery, University at Buffalo, The State University of New York, Buffalo, New York, USA; Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York, USA. 5. Department of Mechanics and Engineering Science, Fudan University, Shanghai, China. Electronic address: szwang@fudan.edu.cn. 6. Beijing Neurosurgical Institute, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. Electronic address: yingzhang829@163.com.
Abstract
BACKGROUND: This study aimed to investigate the hemodynamic changes induced by a flow diverter (FD) and coils in the treatment of internal carotid artery aneurysms, as well as to evaluate the effect of this treatment by using angiographic follow-up data. METHODS: Six large and giant aneurysms were treated by the Tubridge FD and loose packing coils between June 2013 and May 2015. Patient-specific models were constructed and analyzed using a computational fluid dynamics (CFD) method. The virtual FD deployment method was used to implant the Tubridge stent into a 3-dimensional digital subtraction angiographic image of the aneurysms, and the coils were simulated by a porous medium model. RESULTS: Tubridge FD alone can significantly reduce the intra-aneurysmal flow velocity (0.17 ± 0.05 m/s-0.11 ± 0.06 m/s, P < 0.001) and wall shear stress (WSS, 1.39 ± 0.29 Pa-0.77 ± 0.34 Pa, P = 0.001) and increase the low wall shear area (LSA, 6.38% ± 1.49%-34.60% ± 28.90%, P = 0.047). Coils, as a supplementary measure, further reduced the velocity (0.11 ± 0.06 m/s-0.08 ± 0.05 m/s, P = 0.03) and WSS (0.77 ± 0.34 Pa-0.47 ± 0.35 Pa, P = 0.04) and increased the LSA (34.60% ± 28.90%-63.33% ± 34.82%, P = 0.044). Aneurysm with sustained strong inflow after treatment (case 3, 25% reduction in velocity, 12% reduction in WSS, and 16% increment in LSA) showed partial patency, whereas others with a weaker inflow jet (mean 56% reduction in velocity, 74% reduction in WSS, and 1081% increment in LSA) showed complete occlusion at follow-up. CONCLUSIONS: On the basis of using the CFD method, adjunctive coiling with the Tubridge FD placement may significantly reduce intra-aneurysmal flow velocity and WSS, promoting thrombosis formation and occlusion of aneurysms.
BACKGROUND: This study aimed to investigate the hemodynamic changes induced by a flow diverter (FD) and coils in the treatment of internal carotid artery aneurysms, as well as to evaluate the effect of this treatment by using angiographic follow-up data. METHODS: Six large and giant aneurysms were treated by the Tubridge FD and loose packing coils between June 2013 and May 2015. Patient-specific models were constructed and analyzed using a computational fluid dynamics (CFD) method. The virtual FD deployment method was used to implant the Tubridge stent into a 3-dimensional digital subtraction angiographic image of the aneurysms, and the coils were simulated by a porous medium model. RESULTS: Tubridge FD alone can significantly reduce the intra-aneurysmal flow velocity (0.17 ± 0.05 m/s-0.11 ± 0.06 m/s, P < 0.001) and wall shear stress (WSS, 1.39 ± 0.29 Pa-0.77 ± 0.34 Pa, P = 0.001) and increase the low wall shear area (LSA, 6.38% ± 1.49%-34.60% ± 28.90%, P = 0.047). Coils, as a supplementary measure, further reduced the velocity (0.11 ± 0.06 m/s-0.08 ± 0.05 m/s, P = 0.03) and WSS (0.77 ± 0.34 Pa-0.47 ± 0.35 Pa, P = 0.04) and increased the LSA (34.60% ± 28.90%-63.33% ± 34.82%, P = 0.044). Aneurysm with sustained strong inflow after treatment (case 3, 25% reduction in velocity, 12% reduction in WSS, and 16% increment in LSA) showed partial patency, whereas others with a weaker inflow jet (mean 56% reduction in velocity, 74% reduction in WSS, and 1081% increment in LSA) showed complete occlusion at follow-up. CONCLUSIONS: On the basis of using the CFD method, adjunctive coiling with the Tubridge FD placement may significantly reduce intra-aneurysmal flow velocity and WSS, promoting thrombosis formation and occlusion of aneurysms.