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Degradation model of bioabsorbable cardiovascular stents.

Luo Q, Liu X, Li Z, Huang C, Zhang W, Meng J, Chang Z, Hua Z - PLoS ONE (2014)

Bottom Line: 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.This model could eventually be used for design and optimization of bioabsorbable stent.

View Article: PubMed Central - PubMed

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.

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.

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The stented anatomy of the in vivo model after 6-month implantation.
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pone-0110278-g005: The stented anatomy of the in vivo model after 6-month implantation.

Mentions: The degradation condition of the implanted stent of the in vivo models over the 6 months post-implantation can be observed from Figure 4, where it can be seen that the surface and edges of the stents from the in vitro degradation experiment suffered slight erosion, with a smaller area with thin skin fall. Yet, the stents were in overall good condition without any collapse phenomenon. Figure 5 demonstrates the anatomy of stent of the in vivo degradation model over the 6 months post-implantation: the implanted stent was able to keep good mechanical integrity and was successful in maintaining the support stability of blood vessels. It was seen that at 6 months after implantation, there was still minimal structure change in the stents in both the in vitro and in vivo models. The designed stent not only prevented extensive degradation during the six months, but could also support the patency of the blood vessels during 6 month implantation.


Degradation model of bioabsorbable cardiovascular stents.

Luo Q, Liu X, Li Z, Huang C, Zhang W, Meng J, Chang Z, Hua Z - PLoS ONE (2014)

The stented anatomy of the in vivo model after 6-month implantation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4217724&req=5

pone-0110278-g005: The stented anatomy of the in vivo model after 6-month implantation.
Mentions: The degradation condition of the implanted stent of the in vivo models over the 6 months post-implantation can be observed from Figure 4, where it can be seen that the surface and edges of the stents from the in vitro degradation experiment suffered slight erosion, with a smaller area with thin skin fall. Yet, the stents were in overall good condition without any collapse phenomenon. Figure 5 demonstrates the anatomy of stent of the in vivo degradation model over the 6 months post-implantation: the implanted stent was able to keep good mechanical integrity and was successful in maintaining the support stability of blood vessels. It was seen that at 6 months after implantation, there was still minimal structure change in the stents in both the in vitro and in vivo models. The designed stent not only prevented extensive degradation during the six months, but could also support the patency of the blood vessels during 6 month implantation.

Bottom Line: 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.This model could eventually be used for design and optimization of bioabsorbable stent.

View Article: PubMed Central - PubMed

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.

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.

Show MeSH
Related in: MedlinePlus