Flow Diversion and Outcomes of Vertebral Fusiform Aneurysms After Stent-Only Treatment: A Hemodynamic Study.

Li, Wenqiang; Liu, Jian; Zhang, Yisen; Wang, Kun; Tian, Zhongbin; Zhang, Qianqian; Jiang, Chuhan; Yang, Xinjian; Wang, Yang

BACKGROUND The aim of this study was to determine the effectiveness of treating vertebral fusiform aneurysms (VFAs) only with stents. Using computational fluid dynamics, we evaluated the hemodynamic patterns of VFAs after stent-only treatment (SOT) and monitored hemodynamic changes in the side branches. METHODS Between September 2014 and December 2015, we enrolled 10 consecutive patients with VFAs who underwent SOT. Successful aneurysm reconstruction is defined as perfect reconstruction of the parent artery and complete or nearly complete occlusion of the aneurysm. Otherwise, the reconstruction was considered unsuccessful. After SOT, we used computational fluid dynamics to assess hemodynamic changes in aneurysmal velocity, wall shear stress, and relative residual time (RRT) as well as velocity in side branches. RESULTS Ten patients were studied. At follow-up after initial treatment, 7 of the 10 reconstructions were successful. Compared with the 3 unsuccessful reconstructions, successful reconstructions showed a significantly greater increase in the mean RRT (1185.1% vs. 204.8%; P = 0.030) and a greater reduction in mean velocity (44.5% vs. 34.7%; P = 0.053) and wall shear stress (49.2% vs. 27.9%; P = 0.087). The average velocity in the branches decreased by 10.0% after SOT. There was also a significant difference between the mean reduction in the rate of flow velocity in the aneurysm and the side branches (42.1% vs. 10.0%; P < 0.001). CONCLUSIONS We found a significant increase in RRT of successful reconstruction of aneurysms. There may be less effect on the flow in branches arising from VFAs after SOT, whether the aneurysms showed complete occlusion or not.