Dominique Crochet

Drug-Eluting Stents in Bifurcations Bench Study of Strut Deformation and Coating Lesions

Background—The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results—Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberté) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturers data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberté, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturers data/calculated drug application [&mgr;g/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberté, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated (P<0.05). Conclusions—Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating.Background— The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results— Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberte) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturer’s data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberte, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturer’s data/calculated drug application [μg/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberte, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated ( P <0.05). Conclusions— Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating. Received December 22, 2008; accepted January 15, 2010. # CLINICAL PERSPECTIVE {#article-title-2}

Drug-Eluting Stents in Bifurcations

Background—The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results—Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberté) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturers data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberté, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturers data/calculated drug application [&mgr;g/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberté, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated (P<0.05). Conclusions—Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating.Background— The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results— Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberte) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturer’s data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberte, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturer’s data/calculated drug application [μg/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberte, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated ( P <0.05). Conclusions— Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating. Received December 22, 2008; accepted January 15, 2010. # CLINICAL PERSPECTIVE {#article-title-2}

Stent implantation activates RhoA in human arteries: Inhibitory effect of rapamycin

In-stent restenosis is a novel pathobiologic process resulting from vascular smooth muscle cell (VSMC) proliferation, migration and excessive matrix production. The present study was designed to assess the activity of RhoA, a major regulator of VSMC proliferation and migration, after stenting and to determine its role in the neointimal formation. Analysis of RhoA activity in an ex vivo organ culture model of human internal mammary arteries demonstrates that stenting induced a time-dependent increase in RhoA activity (4.9 ± 0.4 vs. 1.2 ± 0.2 in control at 28 days, n = 4, p < 0.0001) associated with a concomitant decrease in p27 expression. Treatment of stented arteries with the permeant RhoA inhibitor TAT-C3 (10 µg/ml) or Rho-kinase inhibitors (Y-27632, 10 µmol/l; fasudil, 10 µmol/l) inhibited both neointimal formation and decrease in p27 expression. Rapamycin (1 and 10 nmol/l) also inhibited neointimal formation, and induced a loss of RhoA expression. The inhibitory effect of rapamycin on neointimal thickening is prevented by the dominant active form of RhoA. Our study shows that stent implantation induces maintained RhoA activation and demonstrates that the inhibitory action of rapamycin on RhoA expression plays a key role in its antirestenotic effect.

Neointimal Hyperplasia after Stenting in a Human Mammary Artery Organ Culture

Although the use of stents has limited the incidence of restenosis, in-stent restenosis remains an important problem. In-stent restenosis is the result of a healing process that induced neointimal hyperplasia through mechanisms that are still not understood. The aim of this study was to analyze the histological consequences of the healing process following stent implantation. Internal mammary arteries from atheroslerotic patients undergoing coronary artery bypass surgery were stented and maintained in culture for 0–28 days. Stent implantation after predilatation induced an extensive loss of endothelial cells whereas direct stenting preserved endothelium between the struts. Morphometric analysis shows that stent placement induced neointimal thickening. Smooth muscle α-actin labeling indicates that neo-intimal formation was mainly due to proliferation and migration of smooth muscle cells. Smooth muscle cell proliferation, assessed by MIB-1 staining, was maximal at day 14 after stent insertion. Human mammary artery organ culture thus provides valuable information on histological consequences of stent implantation with or without predilatation regarding endothelial cell disappearance and neointimal hyperplasia. These data also demonstrate that neointimal thickening induced by stent implantation comprises an intrinsic component resulting from the vessel wall response to stent insertion and suggest that blood factors could play an amplifying but not necessary role.

Drug-Eluting Stents in BifurcationsCLINICAL PERSPECTIVE

Background—The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results—Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberté) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturers data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberté, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturers data/calculated drug application [&mgr;g/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberté, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated (P<0.05). Conclusions—Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating.Background— The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results— Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberte) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturer’s data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberte, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturer’s data/calculated drug application [μg/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberte, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated ( P <0.05). Conclusions— Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating. Received December 22, 2008; accepted January 15, 2010. # CLINICAL PERSPECTIVE {#article-title-2}

Drug-Eluting Stents in BifurcationsCLINICAL PERSPECTIVE: Bench Study of Strut Deformation and Coating Lesions

Background—The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results—Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberté) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturers data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberté, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturers data/calculated drug application [&mgr;g/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberté, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated (P<0.05). Conclusions—Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating.Background— The use of a drug-eluting stent (DES) has strongly limited the incidence of in-stent restenosis in bifurcation lesions; nevertheless, restenosis still remains a problem at the origin of the bifurcation side branch. The aim of this study is to analyze the consequences of the kissing postdilatation technique on 5 DESs, using microfocus x-ray computerized tomography and scanning electron microscopy. Methods and Results— Five different DESs (Cypher, Cypher Select, Endeavor, Taxus Express, and Taxus Liberte) were deployed using kissing postdilatation protocols in a bench-top model. For all types of DES, microfocus x-ray computerized tomography analysis showed that (1) kissing postdilatation of the stent by 2 coaxial balloons caused elliptic deformation in the proximal segment and (2) kissing postdilatation technique reduced the ratio of potential metal to artery (manufacturer’s data/calculated ratio [%]: Cypher, 12.7/8.8; Cypher Select, 13.5/10.2; Endeavor, 19.0/13.3; Taxus Express, 20.5/4.7; Taxus Liberte, 17.9/12.5) and the potential drug application to area in the proximal segment, including the ostial struts (struts adjacent to and lying around the side branch ostium) (manufacturer’s data/calculated drug application [μg/mm2]: Cypher, 1.4/1.0; Cypher Select, 1.4/1.1; Endeavor, 1.6/1.1; Taxus Express, 1.0/0.7; Taxus Liberte, 1.0/0.7). Scanning electron microscopy analysis showed a significantly greater coating damage to the ostial struts in all stents evaluated ( P <0.05). Conclusions— Commercially available DESs subjected to simultaneous kissing balloon postdilatation in an unconstrained model may contribute to side branch ostial restenosis by proximal segment elliptic deformation and damage to the polymer coating. Received December 22, 2008; accepted January 15, 2010. # CLINICAL PERSPECTIVE {#article-title-2}

Fibroélastome papillaire de la valve mitrale

Un homme de 72 ans beneficie d’une echographie cardiaque dans le bilan d’un trouble visuel d’apparition brutale qui s’avere etre une thrombose de la veine centrale de la retine. L’echographie met en evidence une masse intraventriculaire gauche de petite taille implantee a proximite du troisieme segment du feuillet posterieur de la valve mitrale. Cette masse n’a pas pu etre responsable de l’accident visuel recent, mais une indication operatoire est retenue compte tenu du risque emboligene. Un coroscanner est programme dans le bilan preoperatoire (fig. 1). Il confirme la masse pediculee intraventriculaire gauche et montre un reseau coronaire sain.

Masse calcifiée de l’anneau mitral

Un homme de 67 ans, en bon etat general, sans antecedent particulier hormis un accident de la voie publique (AVP) severe a l’âge de 20 ans, consulte aux urgences ophtalmologiques pour cecite brutale de l’œil gauche. Le diagnostic retenu est une thrombose de l’artere centrale de la retine. Le patient beneficie d’une echographie cardiaque qui met en evidence une masse d’allure kystique (centre hypoechogene et corticale hyperechogene) situee a proximite de l’anneau mitral, juste en arriere de la valve posterieure. La valve mitrale est continente. Le bilan biologique est normal. Les serologies hydatidoses sont negatives. Un scanner thoracoabdominal confirme la presence d’une masse calcifiee au niveau du sillon auriculoventriculaire gauche. Une IRM cardiaque est realisee. Celle-ci met en evidence une masse en isosignal T1, hypersignal T2, non rehaussee apres injection de gadolinium.

Myxome de localisation atypique

A l’occasion d’un episode viral, on decouvre, chez une jeune fille de 12 ans, un souffle cardiaque a l’auscultation. Une echographie cardiaque est realisee et montre une masse intraventriculaire droite, situee dans l’infundibulum, mobile a chaque systole. En IRM, cette masse unique est pediculee, implantee sur le septum interventriculaire, et obstrue partiellement l’infundibulum a chaque systole.