Pathology of Acute and Chronic Coronary Stenting in Humans

Farb, Andrew; Sangiorgi, Giuseppe; Carter, Andrew J.; Walley, Virginia M.; Edwards, William D.; Schwartz, Robert S.; Virmani, Renu

doi:10.1161/01.cir.99.1.44

Cited by 787 publications

(528 citation statements)

References 16 publications

(17 reference statements)

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“…7,22,23,32,35,46,77,81,82,86 The mechanical impact of the investigated stents was evaluated in terms of the equivalent von Mises stress (ES) distribution predicted in the artery wall. The ES is calculated as follows:…”

Section: Analysis Of Balloon-expandable Coronary Stentsmentioning

confidence: 99%

“…Over the past two decades, several clinical studies have identified strong correlations between neointimal hyperplasia following coronary stent deployment and both stent-induced arterial injury 7,22,23,32,35,46,77,81,82,86 and altered vessel hemodynamics. 6,17,18,20,21,52,71,79,88 In light of these observations, a significant body of research has been carried out in this area.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Martín¹,

Boyle²

2015

Cardiovasc Eng Tech

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Abstract-Several clinical studies have identified a strong correlation between neointimal hyperplasia following coronary stent deployment and both stent-induced arterial injury and altered vessel hemodynamics. As such, the sequential structural and fluid dynamics analysis of balloon-expandable stent deployment should provide a comprehensive indication of stent performance. Despite this observation, very few numerical studies of balloon-expandable coronary stents have considered both the mechanical and hemodynamic impact of stent deployment. Furthermore, in the few studies that have considered both phenomena, only a small number of stents have been considered. In this study, a sequential structural and fluid dynamics analysis methodology was employed to compare both the mechanical and hemodynamic impact of six balloon-expandable coronary stents. To investigate the relationship between stent design and performance, several common stent design properties were then identified and the dependence between these properties and both the mechanical and hemodynamic variables of interest was evaluated using statistical measures of correlation. Following the completion of the numerical analyses, stent strut thickness was identified as the only common design property that demonstrated a strong dependence with either the mean equivalent stress predicted in the artery wall or the mean relative residence time predicted on the luminal surface of the artery. These results corroborate the findings of the large-scale ISAR-STEREO clinical studies and highlight the crucial role of strut thickness in coronary stent design. The sequential structural and fluid dynamics analysis methodology and the multivariable statistical treatment of the results described in this study should prove useful in the design of future balloon-expandable coronary stents.

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Section: Analysis Of Balloon-expandable Coronary Stentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Martín¹,

Boyle²

2015

Cardiovasc Eng Tech

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“…2,3 Injury stimulates medial smooth muscle cells to undergo proliferation, dedifferentiate with expression of fetal phenotype proteins, and migrate into the intima. The morphologic changes in ultrastructure entail both hyperplasia of the migrant smooth muscle cells and enhanced deposition of extracellular matrix proteins and glycosoaminoglycans, [4][5][6] leading to thickening of the intimal layer and narrowing of the arterial lumen.…”

Section: Introductionmentioning

confidence: 99%

Dose-dependent Inhibition of Myointimal Hyperplasia by Orally Administered Rapamycin

Uchimura

Perera

Fujitani

et al. 2004

Annals of Vascular Surgery

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Myointimal hyperplasia (MIH) after vascular intervention is a major problem. Recent reports describing elimination of within-stent restenosis by means of rapamycin-eluting stents prompted us to examine the effect of systemic oral rapamycin on MIH induced by arterial trauma. We studied the effect of oral rapamycin on MIH after rabbit aorta balloon injury. Thirty-five New Zealand white rabbits (2.5-3 kg) had aortic injury and were given either no rapamycin (control), 0.1 (low dose) rapamycin mg/kg/day, or 0.4 mg/kg/day (high dose). Rapamycin was started 1 week before injury and continued for 3 (4 weeks total) or 6 weeks (7 weeks total) post-injury. Sections were analyzed to measure aortic intima/media area ratios (I:M) at either 3 or 6 weeks. At 3 weeks, the I:M (mean ± SD) for controls was 0.53 ± 0.1; for low dose, 0.17 ± 0.13; and for high dose, 0.24 ± 0.07 (p < 0.001 vs. control). At 6 weeks, the I:M for controls was 0.52 ± 0.12; for low dose-4 weeks, 0.29 ± 0.15; low dose-7 weeks, 0.33 ± 0.07; and high dose-4 weeks, 0.47 ± 0.16. At 6 weeks only the difference between the low dose-4 weeks and control I:M ratios was significant (p = 0.018). The results confirm earlier studies showing that systemic rapamycin inhibits MIH after arterial injury when drug therapy is started before injury. Therapy for 3 or 6 weeks after injury yields similar inhibition, indicating that exposure to the drug early in the response to injury is more important than prolonged exposure. We observed a paradoxical relation between dose and degree of MIH inhibition, with the low dose being more effective than the high dose at both time intervals studied. Overall, the results suggest that oral rapamycin therapy might be a useful adjunct to clinical interventions at risk for development of MIH.

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“…Le traumatisme artériel provoqué par l'implantation d'un stent est très différent de celui qui suit une angioplastie au ballonnet [7]: les barreaux métalliques dilacèrent profondément la paroi artérielle, non seulement au niveau de la plaque d'athérosclérose et de son centre lipidique, mais aussi de la média sous-jacente, avec une relation quasi linéaire entre la sévérité du traumatisme et l'épaississement intimal qu'il engendre (voir Encadré). L'examen de prélèvements post-mortem montre une réaction inflammatoire riche en macrophages et en lymphocytes T, présente à tous les stades de développement de la néointima et prédominant dans les premières semaines [7].…”

Section: Revues Dossier Techniqueunclassified

Prévention des resténoses intrastent: vers un traitementin situ

et al. 2004

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L'introduction des stents à la fin des années 80 a constitué une étape décisive dans le développement des techniques de cardiologie interventionnelle [1] (voir Encadré). En France, 75% à 90% des procédures d'angioplastie coronaire s'accompagnent de l'implantation d'un ou plusieurs stents (environ 120000 stents ont ainsi été implantés en 2000). Cette «stentomanie» s'explique autant par l'efficacité des stents dans le traitement des occlusions coronaires aiguës survenant en cours d'angioplastie que par leur simplicité d'emploi ou encore par la diminution sensible de la fréquence des resténoses par rapport à la seule angioplastie au ballonnet [2, 3]. Dans les études cliniques les plus récentes, l'incidence des resténoses intrastent varie entre 10% et 20 % [4]. Ces chiffres doivent néanmoins être considérés avec précaution, car les critères d'inclusion très stricts aboutissent dans ces grandes études à une sélection de « cas idéaux » (typiquement, des sténoses focales touchant des artères coronaires natives de plus de 3 mm de diamètre) et donc à une très probable sous-évaluation de l'incidence réelle des resténoses intrastent. En cas de resténose, une nouvelle angioplastie est quasiment toujours possible, mais le risque de resténose récurrente peut alors atteindre 50% [5]. Physiopathologie de l'hyperplasie intimale intrastentL'effet protecteur des stents contre les resténoses résulte essentiellement d'un meilleur gain luminal immédiatement après le déploiement du stent (par inhibition du rappel élastique de la paroi artérielle) et d'une prévention du remodelage constrictif chronique (principal mécanisme des resténoses après angioplastie au ballonnet). En revanche, l'hyperplasie intimale est plus marquée qu'après une angioplastie au ballonnet et constitue le mécanisme presque exclusif des resténoses intrastent [6]. MEDECINE/SCIENCES 2004 ; 20 : 98-104 > La pose de stents est devenue la principale technique d'angioplastie coronaire percutanée en France, comme dans les autres pays occidentaux. La principale limite de cette technique est la survenue de resténoses au site d'implantation du stent. Les techniques médicamenteuses de prévention, inefficaces dans l'ensemble, souffrent autant d'une méconnaissance de la physiopathologie des resténoses intrastent que d'une inadéquation entre des traitements systé-miques et un phénomène biologique éminem-ment focal. Des traitement locaux prenant en compte ces données physiopathologiques sont donc en cours d'évaluation chez l'homme. Les premiers résultats cliniques des stents impré-gnés actifs, qui permettent de délivrer localement de fortes concentrations de substances antiproliférantes (sirolimus, paclitaxel…), sont très prometteurs et suggèrent que ces nouveaux stents devraient probablement révolutionner la pratique de la cardiologie interventionnelle. Quant à la thérapie génique, son application au problème des resténoses nécessite une simplification et une amélioration de l'efficacité des techniques de transfert génique. <

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Pathology of Acute and Chronic Coronary Stenting in Humans

Cited by 787 publications

References 16 publications

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Sequential Structural and Fluid Dynamics Analysis of Balloon-Expandable Coronary Stents: A Multivariable Statistical Analysis

Dose-dependent Inhibition of Myointimal Hyperplasia by Orally Administered Rapamycin

Prévention des resténoses intrastent: vers un traitementin situ

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