Expansion and drug elution model of a coronary stent

Migliavacca, Francesco; Gervaso, Francesca; Prosi, Martin; Zunino, Paolo; Minisini, Sara; Formaggia, Luca; Dubini, Gabriele

doi:10.1080/10255840601071087

Cited by 79 publications

(59 citation statements)

References 40 publications

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“…Further inspection of Table 2 shows that the combination of a low-viscosity carrier fluid and extended therapy duration gives rise to a significant increase of drug concentration compared to that which results from the use of [5,[17][18] a high viscosity fluid and a shorter therapy duration.…”

Section: Impact Of Balloon Permeability On Drug Deliverymentioning

confidence: 99%

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Controlling the rate of penetration of a therapeutic drug into the wall of an artery by means of a pressurized balloon

Stark¹,

Gorman²,

Sparrow³

et al. 2013

JBiSE

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The focus of this paper is to propose, model, and characterize a means of accelerating the rate of delivery of therapeutic drugs to human tissues. The investigated means is a pressurized, permeable-walled balloon filled with a homogeneous mixture of the drug and the carrier fluid. The fluid mixture, driven by pressure, traverses the thickness of the balloon wall through laser-drilled pores. The number and deployment of the pores can be controlled to a high degree of precision. As a consequence, the wall of the balloon can be regarded as a homogeneous porous medium, and the traversing fluid flow can be analyzed by means of porous media models. When the balloon is in intimate contact with the surface of a tissue bed, the therapeutic fluid flows in series as it passes through the balloon wall and penetrates the tissue. The flow rate can be controlled by proper selection of the balloon permeability, the viscosity of the flowing medium, and the pressure internal to the balloon. The delivered concentration of the drug was predicted by coupling the present balloon-focused theory with a previously developed tissue-bed model that includes both diffusion and advection processes. The tribologic interaction of the pressurized balloon with an artery wall was investigated experimentally to assess the possible formation of aneurysms.

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Section: Impact Of Balloon Permeability On Drug Deliverymentioning

confidence: 99%

“…For example, it is now common practice to employ drug-coated stents to slow restenosis following angioplasty [1][2][3][4][5][6][7][8]. The transport pathway of the medication first involves mass transfer in the polymerdrug compound that coats the stent and subsequent diffusion of the drug into the tissue.…”

Section: Introductionmentioning

confidence: 99%

Controlling the rate of penetration of a therapeutic drug into the wall of an artery by means of a pressurized balloon

Stark¹,

Gorman²,

Sparrow³

et al. 2013

JBiSE

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“…More important, model validation results against appropriate experimental data may be sensitive to the model boundary conditions. FEM studies on stenting have employed both implicit [Welch, 2008;Migliavacca, 2007;Migliavacca, 2002, Lia;Lim, 2008] and explicit codes [Lim, 2008;Gervaso, 2008;Ju, 2008;De Beulea, 2008;Zahedmanesh, 2009;Mortier, 2009;Pericevic, 2009; and large deformations, explicit code is more attractive. Moreover, the contact algorithm in explicit code is more straightforward than would be achieved with implicit formulations, which makes it the first choice when analyzing complex contacts.…”

Section: Implicit Versus Explicit Femmentioning

confidence: 99%

Finite element methods to analyze helical stent expansion

Paryab

Cronin

Lee‐Sullivan

2013

Numer Methods Biomed Eng

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SUMMARYHelical polymeric stents have been proposed as a suitable geometry for biodegradable drug‐eluting polymer‐based stents. However, helical stents often experience nonuniform local expansion (dog boning), which can prohibit full stent expansion using conventional methods. The development of stents and deployment methods is challenging and can be supported by numerical analysis; however, this complex problem is often approached with simplified boundary conditions that may not be appropriate for helical stents. The finite element method (explicit and implicit) was used to investigate three common stent expansion approaches with a focus on helical stent geometry, which differs from traditional wire mesh stent expansion. Although each of the three methods considered provided some insight into the expansion characteristics, common displacement controlled, and uniform expansion methods were not able to demonstrate the characteristic local deformations observed in expansion. A coupled stent‐balloon model, although computationally expensive, was able to demonstrate the expected nonuniform deformation. To address nonuniform expansion, a progressive expansion approach has been investigated and verified numerically. This method may also provide a suitable solution for nonuniform expansion in other stent designs by minimizing loading and potential damage to the artery that can occur during stent deployment. Copyright © 2013 John Wiley & Sons, Ltd.

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“…Hwang et al 15 predicted the free as well as bound drug concentrations by solving for distribution of free drug and then using a multiplicative factor (partition approach) to predict the concentration of bound drug. Migliavacca et al 16 studied the drug release pattern in vascular wall from drug-eluting stents using a single species approach along with a partition coefficient approach to relate the free and the J Explor Res Pharmacol bound drug concentrations. Borghi et al 17 opined that the inclusion of reversible binding leads to delayed release and that the erosion of polymer affects the drug release from a single strut.…”

Section: Introductionmentioning

confidence: 99%

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confidence: 99%

Modelling Time-dependent Release Kinetics in Stent-based Delivery

Saha¹,

Mandal²

2018

Journal of Exploratory Research in Pharmacology

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IntroductionArterial stenting, acting as a supporting scaffold, has revolutionized the treatment of coronary artery disease, as it reopens the occluded vessel and restores the normal flow of blood. The bare metal stents (BMS s ), while revolutionary at the time, were soon rendered unsatisfactory due to their inability to prevent in-stent restenosis. The next wave of arterial stents coated by drug-the so-called drug-eluting stents (DES s ) raised all sorts of questions by releasing antiproliferative agents in a controlled manner into the injured site to reduce restenosis rates. 1-9 Drug-eluting stents are now the primary choice of percutaneous coronary interventions (PCI s ) in millions of patients, but questions regarding their longevity and safety still arise.Some experimental studies have been carried out in the recent past, with the aim of quantifying the capability of this device to reduce in-stent restenosis after stent implantation. 10-12 Lovich et al. 10 studied the behaviour of heparin in explanted arteries and concluded that the presence of binding sites changes along the transmural direction, being higher in the endothelium and lower in the adventitia. Lovich and Edelman studied the effects of specific binding sites inside the arterial wall on the drug uptake, 13 where the presence of specific binding site action was modelled using the reversible chemical reaction. Sakharov et al. 14 disregarded the convective effects on the transport of free drug. Hwang et al. 15 predicted the free as well as bound drug concentrations by solving for distribution of free drug and then using a multiplicative factor (partition approach) to predict the concentration of bound drug. Migliavacca et al. 16 studied the drug release pattern in vascular wall from drug-eluting stents using a single species approach along with a partition coefficient approach to relate the free and the Modelling Time-dependent Release Kinetics in Stent-based Delivery AbstractBackground and objective: The present study deals with a computational model of the transport and retention of drug within the arterial wall eluted from a drug-eluting stent, to enhance our understanding of the performance of this device. We considered a two-species model (free and bound) incorporating a reversible reaction to describe drug interactions with the constituents of the arterial wall. An axisymmetric model of drug delivery from a pair of stent struts has been developed, where the transport of free drug is modelled as an unsteady reaction-diffusion process, while the bound drug, assuming complete immobilization in the tissue, is modeled as an unsteady reaction process. The model also took into account a second-order binding process that describes a saturating reversible binding and time-dependent release kinetics of the drug-eluting stent. Considering that diffusion takes place over a tortuous path in a porous media, the effects of porosity and tortuosity on diffusion cannot be ruled out from this present investigation.

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Expansion and drug elution model of a coronary stent

Cited by 79 publications

References 40 publications

Controlling the rate of penetration of a therapeutic drug into the wall of an artery by means of a pressurized balloon

Controlling the rate of penetration of a therapeutic drug into the wall of an artery by means of a pressurized balloon

Finite element methods to analyze helical stent expansion

Modelling Time-dependent Release Kinetics in Stent-based Delivery

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