scholarly journals Should ultrathin strut drug eluting stents be considered the new benchmark for novel coronary stents approval? The complex interplay between stent strut thickness, polymeric carriers and antiproliferative drugs

2018 ◽  
Vol 10 (2) ◽  
pp. 678-681 ◽  
Author(s):  
Alessandro Lupi ◽  
Alon Schaffer ◽  
Angelo Sante Bongo
Keyword(s):  
Coronary Stents ◽  
Drug Eluting Stents ◽  
Complex Interplay ◽  
Strut Thickness ◽  
Polymeric Carriers ◽  
Stent Strut ◽  
Drug Eluting

scholarly journals The Newest Generation of Drug-eluting Stents and Beyond

2018 ◽  
Vol 13 (1) ◽  
pp. 54 ◽  
Author(s):  
Dae-Hyun Lee ◽  
Jose M de la Torre Hernandez ◽  
◽  
Keyword(s):  
Control Release ◽  
Radial Force ◽  
Coronary Stents ◽  
Drug Eluting Stents ◽  
Optimal Duration ◽  
Drug Eluting ◽  
The Ideal

There has been a great evolution in the development of coronary stents in order to avoid both restenosis and thrombosis. Improvements have led to improvements in the design and conformation of metallic or resorbable structures, with an adequate balance between trackability and radial force, the development of antiproliferative drugs and the polymers to control release and allow adequate endothelialisation and an optimal duration of the antiplatelet regimen. Some suggestions are provided about the ideal characteristics of future coronary stents.

scholarly journals Evolution of Coronary Stents: From Bare-Metal Stents to Fully Biodegradable, Drug-Eluting Stents

2013 ◽  
Vol 3 (1-2) ◽  
pp. 9-24 ◽  
Author(s):  
Jason Foerst ◽  
Marc Vorpahl ◽  
Michael Engelhardt ◽  
Till Koehler ◽  
Klaus Tiroch ◽  
...  
Keyword(s):  
Bare Metal Stents ◽  
Coronary Stents ◽  
Drug Eluting Stents ◽  
Metal Stents ◽  
Bare Metal ◽  
Drug Eluting

Stent fracture and restenosis after placement of a drug-eluting device in the vertebral artery origin and treatment with the stent-in-stent technique

2007 ◽  
Vol 106 (5) ◽  
pp. 907-911 ◽  
Author(s):  
Seong-Rim Kim ◽  
Min-Woo Baik ◽  
Seung-Hoon Yoo ◽  
Ik-Seong Park ◽  
Sang-Don Kim ◽  
...  
Keyword(s):  
Vertebral Artery ◽  
Stent Placement ◽  
Coronary Stents ◽  
Drug Eluting Stent ◽  
Stent Fracture ◽  
Stent Restenosis ◽  
Stent Strut ◽  
Drug Eluting ◽  
In Stent Restenosis

✓ The authors report two cases of stent fracture and restenosis after placement of a drug-eluting device in the vertebral artery (VA) origin, and describe management of restenosis with the stent-in-stent technique. Two women, one 62 and the other 67 years of age, underwent stent placement in the VA origin to treat symptomatic and angiographically significant stenosis in this vessel. Sirolimus-eluting coronary stents (Cypher) were used in both cases. Four months after placement of the devices, the symptoms recurred. Follow-up angiography performed 5 months after insertion of the devices revealed a transverse stent fracture with separation of the fragments and severe in-stent restenosis in both cases. The restenoses were treated with reinsertion of coronary stents (Cypher and Jostent FlexMaster) by using the stent-in-stent technique. After stent reinsertion, the patients exhibited relief of symptoms. This paper is the first report of fracture in a drug-eluting stent and restenosis after stent placement in the VA origin. Restenosis caused by such a fracture can be managed successfully by performing the stent-in-stent maneuver. The physical properties of metallic devices, stent strut geometry, and anatomical peculiarities of the subclavian artery may be associated with stent fractures. Earlier follow-up angiography studies (within 6 months) are warranted.

Experimental Validation of the Influence of Stent Strut Compression on Artery Wall Drug Mass Transport

2009 ◽  
Author(s):  
Barry M. O’Connell ◽  
Tim M. McGloughlin ◽  
Michael T. Walsh
Keyword(s):  
Interventional Procedures ◽  
Experimental Validation ◽  
The Body ◽  
Drug Eluting Stents ◽  
Peripheral Arteries ◽  
Plaque Progression ◽  
Artery Wall ◽  
Stent Strut ◽  
Drug Eluting ◽  
Ischemic Attack

Atherosclerosis is a degenerative disease that affects coronary, carotid and other peripheral arteries in the body. Arterial occlusions ensuing from aggressive atherosclerotic plaque progression can often culminate in an ischemic attack, such as an apoplectic attack or a myocardial infarction [1–3]. Several interventional procedures are available to the clinician but in recent years drug eluting stents (DES) have become the preferred choice and by the beginning of 2006 more than 8 out of 10 coronary stents were DES [4] at a cost of between $4 and $5 billion annually [5].

The Localized Hemodynamics of Drug-Eluting Stents Are Not Improved by the Presence of Magnetic Struts

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
P. R. S. Vijayaratnam ◽  
T. J. Barber ◽  
J. A. Reizes
Keyword(s):  
Blood Flow ◽  
Stent Thrombosis ◽  
Separated Flow ◽  
Drug Eluting Stents ◽  
Magnetic Flux Density ◽  
Drug Eluting Stent ◽  
Shear Stresses ◽  
Stent Strut ◽  
Drug Eluting ◽  
Wall Shear

The feasibility of implementing magnetic struts into drug-eluting stents (DESs) to mitigate the adverse hemodynamics which precipitate stent thrombosis is examined. These adverse hemodynamics include platelet-activating high wall shear stresses (WSS) and endothelial dysfunction-inducing low wall shear stresses. By magnetizing the stent struts, two forces are induced on the surrounding blood: (1) magnetization forces which reorient red blood cells to align with the magnetic field and (2) Lorentz forces which oppose the motion of the conducting fluid. The aim of this study was to investigate whether these forces can be used to locally alter blood flow in a manner that alleviates the thrombogenicity of stented vessels. Two-dimensional steady-state computational fluid dynamics (CFD) simulations were used to numerically model blood flow over a single magnetic drug-eluting stent strut with a square cross section. The effects of magnet orientation and magnetic flux density on the hemodynamics of the stented vessel were elucidated in vessels transporting oxygenated and deoxygenated blood. The simulations are compared in terms of the size of separated flow regions. The results indicate that unrealistically strong magnets would be required to achieve even modest hemodynamic improvements and that the magnetic strut concept is ill-suited to mitigate stent thrombosis.

Biodegradable-polymer versus durable-polymer drug eluting stents for coronary artery disease: systematic review and a meta-analysis

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Toyota ◽  
T Morimoto ◽  
T Kitai ◽  
M Park ◽  
Y Sasaki ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Clinical Outcomes ◽  
First Generation ◽  
Meta Analysis ◽  
Drug Eluting Stents ◽  
Target Vessel ◽  
Strut Thickness ◽  
Drug Eluting ◽  
Artery Disease

Abstract Background Biodegradable polymer drug-eluting stents (BP-DES) has been developed to overcome the potential drawbacks of the first-generation durable polymer drug-eluting stents (DP-DES). However, it is still under debate whether BP-DES is associated with superior efficacy and safety over DP-DES. Purpose We sought to compare the effects of BP-DES and DP-DES in patients with coronary artery disease. Methods We performed systematic review and a meta-analysis of randomized controlled trials comparing BP-DES and DP-DES on clinical outcomes in patients with coronary artery disease using CE-mark approved drug-eluting stents (DES) with at least 1-year follow-up. We included 32 studies involving 39,686 patients (BP-DES: 21,439 patients, and DP-DES: 18,247 patients). Primary outcome measure was target vessel failure (TVF; equivalent to the composite of cardiac death, target-vessel myocardial infarction, or ischemia-driven target vessel revascularization). We performed subgroup analysis according to the DP-DES generations (newer-generation DP-DES: 15,179patients, and first-generation DP-DES: 3,068 patients), and the effects of newer-generation DP-DES was compared with the BP-DES according to the BP-DES strut thickness (Ultra-thin strut [<80μm]: 7,572 patients, Thin-strut [80–100μm]: 5,465 patients, and Thick-strut [≥80μm]: 5,876 patients). Results The odds for TVF was not significantly different between the BP-DES group and the DP-DES group in the entire study population (odds ratio [OR] 0.96, 95% confidence interval [CI] [0.90–1.02], P=0.20). The odds for TVF was significantly low in the BP-DES group relative to the first-generation DP-DES group, however the odds were comparable between the BP-DES group and the newer-generation DP-DES group (BP-DES versus first-generation DP-DES: OR 0.82, 95% CI [0.73–0.92], P<0.001, and BP-DES versus newer-generation DP-DES: OR 1.00, 95% CI [0.93–1.08], P=0.99). We also found no significant differences between the BP-DES and newer-generation DP-DES, in all subgroups stratified by the BP-DES strut thickness (Ultra-thin strut BP-DES versus newer-generation DP-DES: OR 0.88, 95% CI [0.76–1.02], P=0.10, Thin-strut BP-DES versus newer-generation DP-DES: OR 1.01, 95% CI [0.90–1.13], P=0.89, and Thick strut BP-DES versus newer-generation DP-DES: OR 1.11, 95% CI [0.99–1.25], P=0.08). Conclusions In this meta-analysis of randomized controlled trials evaluating clinical outcomes, there was no significant differences between BP-DES and DP-DES. We found beneficial effects of BP-DES relative to the first-generation DP-DES, however, there was no statistical differences between BP-DES and newer-generation DP-DES, irrespective of the BP-DES strut thickness. Pooled odds ratios for clinical outcomes Funding Acknowledgement Type of funding source: None

scholarly journals PDLLA-Zn-nitrided Fe bioresorbable scaffold with 53-μm-thick metallic struts and tunable multistage biodegradation function

2021 ◽  
Vol 7 (23) ◽  
pp. eabf0614
Author(s):  
Danni Shen ◽  
Haiping Qi ◽  
Wenjiao Lin ◽  
Wanqian Zhang ◽  
Dong Bian ◽  
...  
Keyword(s):  
Sacrificial Layer ◽  
Drug Eluting Stents ◽  
Subsequent Stage ◽  
Bioresorbable Scaffold ◽  
Strut Thickness ◽  
Mechanical Integrity ◽  
Initial Stage ◽  
Radial Strength ◽  
Drug Eluting ◽  
Drug Coating

Balancing the biodegradability and mechanical integrity of a bioresorbable scaffold (BRS) with time after implantation to match the remodeling of the scaffolded blood vessel is important, but a key challenge in doing so remains. This study presents a novel intercalated structure of a metallic BRS by introducing a nanoscale Zn sacrificial layer between the nitrided Fe platform and the sirolimus-carrying poly(d,l-lactide) drug coating. The PDLLA-Zn-FeN BRS shows a multistage biodegradation behavior, maintaining mechanical integrity at the initial stage and exhibiting accelerated biodegradation at the subsequent stage in both rabbit abdominal aortas and human coronary arteries, where complete biodegradation was observed about 2 years after implantation. The presence of the nanoscale Zn sacrificial layer with an adjustable thickness also contributes to the tunable biodegradation of BRS and allows the reduction of the metallic strut thickness to 53 μm, with radial strength as strong as that of the current permanent drug-eluting stents.

The influence of strut thickness and cell design on immediate apposition of drug-eluting stents assessed by optical coherence tomography

2009 ◽  
Vol 134 (2) ◽  
pp. 180-188 ◽  
Author(s):  
Jun Tanigawa ◽  
Peter Barlis ◽  
Konstantinos Dimopoulos ◽  
Miles Dalby ◽  
Philip Moore ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Drug Eluting Stents ◽  
Cell Design ◽  
Optical Coherence ◽  
Strut Thickness ◽  
Drug Eluting

Modeling Drug Eluting Stents for Coronary Artery Bifurcation Considering Non-Newtonian Effects

2010 ◽  
Author(s):  
Marjan Molavi Zarandi ◽  
Rosaire Mongrain ◽  
Olivier F. Bertrand
Keyword(s):  
Arterial Wall ◽  
Drug Eluting Stents ◽  
Drug Eluting Stent ◽  
Simulation Techniques ◽  
Drug Concentrations ◽  
Conventional Drug ◽  
Computational Fluid Dynamics Analysis ◽  
Stent Strut ◽  
Drug Eluting ◽  
Stenotic Arteries

Drug Eluting Stents (DES) are commonly used for the treatment of stenotic arteries. Restenosis can be treated by delivering anti-thrombotic and anti-proliferative drugs to the arterial wall. The main mechanism of the drug eluting stent is to allow diffusion of the drug from the coating on the stent, into the arterial wall over a prolonged period of time. Investigation of blood flow hemodynamics and shear stress are of great importance in understanding the transport of drugs through the circulatory systems and predicting the performance of drug eluting stents. While drug eluting stent effectively reduces restenosis rate, the conventional drug eluting stent should be optimized to be used in the bifurcation stenting. Various flow patterns due to specific designs of drug eluting stent influence drug delivery. Numerical simulation techniques are appropriate approaches to study such phenomena which can be used to optimize the design of drug eluting stents for bifurcations. In this paper, the complexity of drug eluting stent function in the bifurcation is presented by employing computational fluid dynamics analysis for various stent strut designs. Drug transportation through the lumen and determination of local drug concentrations in arterial wall is carried out for both Newtonian and non-Newtonian flow conditions. It is, to the author’s best knowledge, the first investigation of drug dispersion in arterial bifurcation considering the effects of both the blood rheological properties and stent strut design.

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