A novel design of a noncylindric stent with beneficial effects on flow characteristics: An experimental and numerical flow study in an axisymmetric arterial model with sequential mild stenoses

Papaioannou, TG; Christofidis, CC; Mathioulakis, DS; Stefanadis, CI

dc.contributor.author	Papaioannou, TG	en
dc.contributor.author	Christofidis, CC	en
dc.contributor.author	Mathioulakis, DS	en
dc.contributor.author	Stefanadis, CI	en
dc.date.accessioned	2014-03-01T01:25:43Z
dc.date.available	2014-03-01T01:25:43Z
dc.date.issued	2007	en
dc.identifier.issn	0160-564X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17745
dc.subject	ostial lesions	en
dc.subject	recirculation	en
dc.subject	separation zones	en
dc.subject	in-stent	en
dc.subject	restenosis	en
dc.subject	intravascular devices	en
dc.subject	computational fluid dynamics	en
dc.subject	flow visualization	en
dc.subject	coronary flow	en
dc.subject.classification	Engineering, Biomedical	en
dc.subject.classification	Transplantation	en
dc.subject.other	WALL SHEAR-STRESS	en
dc.subject.other	DESCENDING CORONARY-ARTERY	en
dc.subject.other	DRUG-ELUTING STENTS	en
dc.subject.other	OSTIAL LESIONS	en
dc.subject.other	FLUID-DYNAMICS	en
dc.subject.other	IN-VIVO	en
dc.subject.other	ATHEROSCLEROSIS	en
dc.subject.other	IMPLANTATION	en
dc.subject.other	INFLAMMATION	en
dc.subject.other	RESTENOSIS	en
dc.title	A novel design of a noncylindric stent with beneficial effects on flow characteristics: An experimental and numerical flow study in an axisymmetric arterial model with sequential mild stenoses	en
heal.type	journalArticle	en
heal.identifier.primary	10.1111/j.1525-1594.2007.00431.x	en
heal.identifier.secondary	http://dx.doi.org/10.1111/j.1525-1594.2007.00431.x	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	The objective of this study was to investigate whether a novel noncylindric "stent," implanted upstream of one or more mild arterial stenoses could be beneficial, by increasing in-stent wall shear stresses (WSS) and by limiting the flow recirculation zones in the vicinity of the stenoses. An in vitro model employing flow visualization, and computational fluid dynamics were used for the study of steady and unsteady flow fields in a model of a coronary artery with two sequential 50% stenoses. Two different tube-entrance geometries (a cylindric and a convergent nozzle), modeling an ostial stented arterial segment, were studied regarding their effect on flow patterns and WSS at various Reynolds numbers (Re = 200-800). In this preliminary study, the internal walls of these tube entrance geometries were smooth, not taking into account the roughness of the actual stent's strut. "In-stent" WSS was significantly increased at the noncylindric configuration compared to that in the regular cylindric geometry. The difference of the spatially averaged "in-stent" WSS between the two designs gradually increased with the increase in Re, reaching a peak value up to 50% in the case of the noncylindric endovascular device, for the examined Re range. For the same configuration, both the experimental and numerical analyses indicated a decrease in flow recirculation region at the vicinity distally to a sequential stenosis up to 6%, and the mean flow velocity was increased for both steady and pulsatile flow. These effects of the new "stent" configuration could be important for the delay of restenosis processes and should be further investigated in vivo.	en
heal.publisher	BLACKWELL PUBLISHING	en
heal.journalName	ARTIFICIAL ORGANS	en
dc.identifier.doi	10.1111/j.1525-1594.2007.00431.x	en
dc.identifier.isi	ISI:000248193800006	en
dc.identifier.volume	31	en
dc.identifier.issue	8	en
dc.identifier.spage	627	en
dc.identifier.epage	638	en