title: Mechanism of luminal patency of the self-expanding Sideguard sidebranch stent: evaluation by intravascular ultrasound and optical coherence tomography.
abstract: BACKGROUND
  The Cappella Sideguard (CS) sidebranch stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the sidebranch ostium designed to treat bifurcation lesions.
  
  
  OBJECTIVE
  To evaluate the mechanism of long-term lumen patency of the novel, self-expanding CS sidebranch stent compared with a balloon-expandable stent in the main vessel.
  
  
  METHODS
  We performed intravascular ultrasound postintervention and at follow-up in 24 CS stents and in 28 balloon-expandable drug-eluting stents deployed in the corresponding main vessel. Thirteen patients also had optical coherence tomography (OCT) at follow-up to evaluate neointimal hyperplasia and strut coverage.
  
  
  RESULTS
  CS stent area at the sidebranch carina increased significantly from 3.8 ± 1.2 mm(2) postintervention to 4.6 ± 1.2 mm(2) at follow-up (P < 0.001), resulting in no change in lumen area (3.8 ± 1.2 mm(2) to 3.7 ± 1.2 mm(2) , P = 0.72) despite a neointimal area at follow-up of 0.9 ± 0.8 mm(2) . Volumetric changes were similar, and the distribution of neointimal hyperplasia peaked 1-2 mm distal to the carina. Change of lumen volume inversely correlated to the neointimal volume (R = -0.48, P < 0.001), but correlated positively to the change in stent volume (R = 0.52, P < 0.0001). By OCT, most CS struts were covered (100% [98.9, 100]) at the bifurcation site, whereas 61% of floating DES struts that crossed the sidebranch were covered by smooth tissue with a similar texture compared with neointima.
  
  
  CONCLUSIONS
  Although neointimal hyperplasia accumulates within the CS stent mainly 1-2 mm distal to the carina, the self-expanding CS stent may be effective in maintaining an adequate patency in the sidebranch by continued stent expansion noted at follow-up.
authors.affiliation: Clinical Trials Center, Cardiovascular Research Foundation, New York, New York; Division of Cardiology, Columbia University Medical Center, New York, New York.
authors.forename: Shixin
authors.initials: S
authors.lastname: Ma
authors.forename: Akiko
authors.initials: A
authors.lastname: Maehara
authors.forename: Karl E
authors.initials: KE
authors.lastname: Hauptmann
authors.forename: Giulio
authors.initials: G
authors.lastname: Guagliumi
authors.forename: Orazio
authors.initials: O
authors.lastname: Valsecchi
authors.forename: Angelina N
authors.initials: AN
authors.lastname: Vassileva
authors.forename: Yolande
authors.initials: Y
authors.lastname: Appelman
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sangiorgi
authors.forename: Francesco
authors.initials: F
authors.lastname: Prati
authors.forename: Gary S
authors.initials: GS
authors.lastname: Mintz
mesh_terms: D000368:Aged; D000497:Alloys; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000379:methods; D016009:Chi-Square Distribution; D017023:Coronary Angiography / Q000379:methods; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000628:therapy*; D054855:Drug-Eluting Stents; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D058426:Neointima / Q000473:pathology / Q000503:physiopathology; D018583:Pliability; D011446:Prospective Studies; D011474:Prosthesis Design; D018709:Statistics, Nonparametric; D041623:Tomography, Optical Coherence; D018084:Ultrasonography, Interventional; D014654:Vascular Patency / Q000502:physiology*
chemical_list: D000497:Alloys; C013616:nitinol
keywords: bifurcation; intravascular ultrasound; optical coherence tomography; stent