Is the "candy-wrapper" effect of (32)P radioactive beta-emitting stents due to remodeling or neointimal hyperplasia? Insights from intravascular ultrasound.
A recognized limitation of radioactive stents is the development of restenosis at the stent edges, known as the "candy-wrapper" effect. The mechanisms of this effect remain incompletely understood and controversial. The aim of this study is to assess the effect of endovascular irradiation on neointima formation and vascular remodeling. (32)P Palmaz-Schatz stents (1.5-4 microCi) were implanted in 11 patients with restenosis after previous percutaneous transluminal coronary angioplasty (PTCA). Intravascular ultrasound (IVUS) images of target sites and adjunct vessel segments were acquired both during intervention and after 6 months. The angiographic restenosis rate was 54%, and the MLD decreased from 2.21 +/- 0.6 mm to 1.38 +/- 0.4 mm at follow-up (P < 0.01). IVUS analysis demonstrated that late lumen loss was the result of neointimal tissue proliferation, which was nonuniformly distributed and exaggerated at both the central articulation and the distal stent edges. Negative remodeling did not contribute to restenosis. In contrast, we found a linear relationship between increase of area stenosis and a positive remodeling index (r = 0.84, P < 0.0001). Restenosis after implantation of (32)P Palmaz-Schatz stents was mainly the result of neointimal tissue proliferation which tended to be nonuniformly distributed in the stent articulation and edges. Negative remodeling or stent recoil was not observed. Cathet Cardiovasc Intervent 2001;54:41-48.
Hansen
A
A
Department of Cardiology, University of Heidelberg, Heidelberg, Germany. alexander_hansen@med.uni-heidelberg.de
Hehrlein
C
C
Hardt
S
S
Bekeredjian
R
R
Brachmann
J
J
Kubler
W
W
Bode
C
C
Kuecherer
H F
HF
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000528:radiation effects*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D006965:Hyperplasia / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010761:Phosphorus Radioisotopes / Q000009:adverse effects; D015607:Stents / Q000009:adverse effects*; D018084:Ultrasonography, Interventional
D010761:Phosphorus Radioisotopes