Hemodynamic study of overlapping bare-metal stents intervention to aortic aneurysm

Peng Zhang^a, Anqiang Sun ^a,*, Fan Zhan^a, Jingyuan Luan^b, Xiaoyan Deng^a,*

a. Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China

b. Department of Interventional Radiology and Vascular Surgery, Peking University Third Hospital, North Garden Road 49, Haidian district, Beijing 100191, China

Abstract

       To investigate the hemodynamic performance of overlapping bare-metal stents intervention treatment to thoracic aortic aneurysms (TAA), three simplified TAA models, representing, no stent, with a single stent and 2 overlapped stents deployed in the aneurismal sac, were studied and compared in terms of flow velocity, wall shear stress (WSS) and pressure distributions by means of computational fluid dynamics. The results showed that overlapping stents intervention induced a flow field of slow velocity near the aneurismal wall. Single stent deployment in the sac reduced the jet-like flow formed prior to the proximal neck of the aneurysm, which impinged on the internal wall of the aneurysm. This jet-like flow vanished completely in the overlapping double stents case. Overlapping stents intervention led to an evident decrease in WSS, meanwhile the pressure acting on the wall of the aneurysm was reduced slightly and presented more uniform distribution. The results therefore indicated that overlapping stents intervention may effectively isolate the thoracic aortic aneurysm, protecting it from rupture. In conclusion, overlapping bare-metal stents may serve a similar purpose to that of the multilayer aneurysm repair system (MARS) manufactured by Cardiatis SA (Isnes, Belgium).

Key words:

Thoracic aortic aneurysm; Overlapping bare-metal stents; Hemodynamics; Numerical simulation;