Analysis of Vascular Mechanical Characteristics after Coronary Degradable Stent Implantation.

Hao Ding,Haoyu Liu,Ying Zhang,Yujia Liu,Yuling Gu,Chunxun Shi,Zhichao Nie

doi:10.1155/2019/8265374

Abstract

Purpose To explore the effect of vascular stress changes on endothelial function recovery and vascular restenosis inhibition, under the condition of dynamic degradation process of the degradable stent. Methods Fitting the material parameters of the hyperelastic vascular constitutive relationship, the stress distribution of the intima of the blood vessel before the stent was implanted and during the dynamic degradation was calculated by numerical simulation. In vitro culture experiments were carried out, and the stretch ratios of the silicone chamber were set to 0%, 5%, 10%, and 15%, respectively, to simulate the effects of different degradation stages on the growth state of endothelial cells. Results After the stent was completely degraded, the circumferential intimal stress (strain) of the vessel was recovered to 0.137 MPa, 5.5%, which was close to the physiological parameters (0.122 MPa, 4.8%) before stent implantation. In vitro experiments showed that the endothelial cell survival rate was the highest under the condition of circumferential stress (strain) of 0.1 MPa, 5%, and all adhesion growth could be achieved. Conclusions With the occurrence of degradation process of the stent, the circumferential stress (strain) of the intima was recovered to a range close to physiological parameters, which promotes the growth of endothelial cells. The recovery of intimal function can effectively inhibit the process of vascular restenosis. The results can provide a theoretical basis and experimental platform for the study of coronary intervention for the treatment of vascular restenosis.

Highlights

Coronary heart disease has become one of the most common and serious diseases that endanger human life. e cause of this disease is that atherosclerotic plaque formed in the coronary arteries blocks blood ow and forms a fatal longterm hidden danger
The usual metal stent will be permanently present in the blood vessels of the human body, causing the endothelial cells (ECs) to be damaged in the contact site, which will inevitably lead to a blood vessel remodeling reaction
According to Fung's hypothesis about the quasi-elasticity of biological so tissue, the relationship between stress and strain of arterial vessels is not single-valued during the speci ed loading and unloading process. ey will creep under constant stress and relax under constant strain. erefore, the material properties of the coronary arteries cannot be described by a few coe cients like homogenous materials [8]

Summary

Introduction

Coronary heart disease has become one of the most common and serious diseases that endanger human life. e cause of this disease is that atherosclerotic plaque formed in the coronary arteries blocks blood ow and forms a fatal longterm hidden danger. Coronary heart disease has become one of the most common and serious diseases that endanger human life. E cause of this disease is that atherosclerotic plaque formed in the coronary arteries blocks blood ow and forms a fatal longterm hidden danger. Mechanical expansion of the lesion by coronary stenting is an e ective treatment to maintain blood ow. The usual metal stent will be permanently present in the blood vessels of the human body, causing the endothelial cells (ECs) to be damaged in the contact site, which will inevitably lead to a blood vessel remodeling reaction. A er coronary stent implantation, the mechanical environment of the vascular wall changes, resulting in intimal injury, which causes blood cells to adhere and aggregate in the blood ow, and eventually causes intimal hyperplasia and restenosis [2]

Methods

Results

Conclusion