Comparative Study of the Elasticity of the Aorta and Synthetic Vascular Prostheses Made by Electroforming - Approach to Overcome the Biomechanical Mismatch

Shota Zhorzholiani, Eugeny Talygin, Yury Cygankov, Andrey Agafonov, Alexander Gorodkov, Leo Bockeria

Bakulev Research Center for Cardiovascular Surgery, Moscow, Russia

Date, time and location: 2018.05.25 13:30, Congress Hall, 2F–B

Abstract

It has been shown that dynamic geometric configuration of the aorta provides the conditions for self-organization and maintenance of a tornado-like blood flow in aortic lumen. This allows energy losses minimization due to maintaining the homogeneous 3D moving boundary layer along the aorta’s length during cardiac cycle. Elasticity distribution deviation along the aorta leads to local thickening of the boundary layer with consequent formation of flow separation and stagnant zones. Therefore, implantation of a vascular prosthesis(VP), substantially different from the aorta, inevitably leads to a boundary layer violation.

AIM: To study the regularity of the elasticity distribution along the aorta, and the manufacturing of a synthetic VP, that would not change the dynamic configuration of the aortic flow channel.

METHODS: Elasticity of the aorta and VP samples was examined on INSTRON 5965 and specially designed ex vivo hemodynamic test stand. Vascular prostheses were made by the electrospinning technics.

RESULTS: The elasticity decreased along the aorta, which ensured the maintenance of a constant converging configuration of the channel corresponding to conditions of self-organization of tornado-like jet throughout the cardiac cycle. The study of elasticity of synthetic VP made of several polymers has shown that their extensibility is many times greater than that of the native aorta under physiological pressure. The necessary range of deformation characteristics change was found in the prostheses made from a mixture of copolymers fluoroplastic F-26 and synthetic rubber SCF-26 in the selected proportion 85%/15%.

CONCLUSION: It has been shown that a synthetic VP made of a mixture of polymers F-26 and SCF-26 allows reproducing the dynamic extensibility of the native aorta. Varying the elasticity of the prosthesis is possible by changing the proportion of polymers in the mixture and changing the thickness of the prosthetic wall. The work was supported by the RSCF (16-15-00109)