title: Intravascular ultrasound comparison of small coronary lesions between novel guidewire-based sirolimus-eluting stents and conventional sirolimus-eluting stents.
abstract: BACKGROUND
  The Sparrow stent system (Biosensors International) consists of a self-expanding, ultra-thin nitinol stent mounted within a 0.014″ guidewire designed for small or tortuous coronary lesions. We compared the intravascular ultrasound (IVUS) findings between the novel self-expanding sirolimus-eluting stent (Sparrow-SES) and a conventional balloon-expandable sirolimus-eluting stent (Cypher-SES) in patients with small coronary disease.
  
  
  METHODS
  We examined 14 lesions treated with the Sparrow-SES from CARE II, compared with 22 small vessel lesions treated with Cypher-SES. IVUS examination was performed post-procedure and 8 months later. Volumetric data were standardized by length as volume index (VI; mm³/mm).
  
  
  RESULTS
  While baseline stent VI trended smaller in Sparrow-SES, follow-up stent VI became similar between the 2 groups due to a significant increase of stent VI in self-expanding Sparrow-SES during the follow-up period. At 8 months, Sparrow-SES showed greater neointima than Cypher-SES (0.8 ± 0.6 mm³/mm vs 0.2 ± 0.2 mm³/mm; P<.001). However, the decrease in lumen VI was only 0.3 ± 0.7 mm³/mm in Sparrow-SES, as compared to 0.1 ± 0.3 mm³/mm in Cypher-SES (P=.259), since the late loss due to neointimal hyperplasia was partly counterbalanced by the chronic stent expansion in Sparrow-SES.
  
  
  CONCLUSIONS
  While 8-month follow-up of Sparrow-SES revealed greater amounts of neointimal hyperplasia compared with conventional Cypher-SES, chronic stent expansion preserved the lumen by increasing stent volume. This novel, guidewire-based, self-expanding stent system designed to be delivered through complex anatomies may be useful to treat patients with small-caliber coronary lesions by offering sufficient lumen preservation at follow-up.
authors.affiliation: Division of Cardiovascular Medicine, Stanford University, 300 Pasteur Drive, Room H3554, Stanford, California 94305- 5637, USA.
authors.forename: Teruyoshi
authors.initials: T
authors.lastname: Kume
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Bon-Kwon
authors.initials: BK
authors.lastname: Koo
authors.forename: Roberto
authors.initials: R
authors.lastname: Botelho
authors.forename: Stefan
authors.initials: S
authors.lastname: Verheye
authors.forename: Robert
authors.initials: R
authors.lastname: Whitbourn
authors.forename: Ian
authors.initials: I
authors.lastname: Meredith
authors.forename: Stephen
authors.initials: S
authors.lastname: Worthley
authors.forename: Koh Tian
authors.initials: KT
authors.lastname: Hai
authors.forename: Paul G
authors.initials: PG
authors.lastname: Yock
authors.forename: Flavio Roberto
authors.initials: FR
authors.lastname: Azevedo de Oliveira
authors.forename: Alexandre
authors.initials: A
authors.lastname: Abizaid
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
mesh_terms: D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000473:pathology; D054855:Drug-Eluting Stents / Q000145:classification*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D058426:Neointima / Q000000981:diagnostic imaging / Q000473:pathology; D011446:Prospective Studies; D012189:Retrospective Studies; D016037:Single-Blind Method; D020123:Sirolimus; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D020123:Sirolimus