title: Degradation model of bioabsorbable cardiovascular stents.
abstract: This study established a numerical model to investigate the degradation mechanism and behavior of bioabsorbable cardiovascular stents. In order to generate the constitutive degradation material model, the degradation characteristics were characterized with user-defined field variables. The radial strength bench test and analysis were used to verify the material model. In order to validate the numerical degradation model, in vitro bench test and in vivo implantation studies were conducted under physiological and normal conditions. The results showed that six months of degradation had not influenced the thermodynamic properties and mechanical integrity of the stent while the molecular weight of the stents implanted in the in vivo and in vitro models had decreased to 61.8% and 68.5% respectively after six month's implantation. It was also found that the degradation rate, critical locations and changes in diameter of the stents in the numerical model were in good consistency in both in vivo and in vitro studies. It implies that the numerical degradation model could provide useful physical insights and prediction of the stent degradation behavior and evaluate, to some extent, the in-vivo performance of the stent. This model could eventually be used for design and optimization of bioabsorbable stent.
authors.affiliation: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China; Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Qiyi
authors.initials: Q
authors.lastname: Luo
authors.affiliation: Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Xiangkun
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China; Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Li
authors.affiliation: Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Chubo
authors.initials: C
authors.lastname: Huang
authors.affiliation: Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Meng
authors.affiliation: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China; Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Chang
authors.affiliation: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China; Shanghai MicroPort Medical (Group) Co., Ltd., Shanghai, China.
authors.forename: Zezhao
authors.initials: Z
authors.lastname: Hua
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D006801:Humans; D008422:Materials Testing; D008962:Models, Theoretical; D015607:Stents; D013552:Swine; D013997:Time Factors