title: Geometric vascular remodeling after balloon angioplasty and beta-radiation therapy: A three-dimensional intravascular ultrasound study.
abstract: BACKGROUND
  Endovascular radiation appears to inhibit intimal thickening after overstretching balloon injury in animal models. The effect of brachytherapy on vascular remodeling is unknown. The aim of the study was to determine the evolution of coronary vessel dimensions after intracoronary irradiation after successful balloon angioplasty in humans.
  
  
  RESULTS
  Twenty-one consecutive patients treated with balloon angioplasty and beta-radiation according to the Beta Energy Restenosis Trial-1.5 were included in the study. Volumetric assessment of the irradiated segment and both edges was performed after brachytherapy and at 6-month follow-up. Intravascular ultrasound images were acquired by means of ECG-triggered pullback, and 3-D reconstruction was performed by automated edge detection, allowing the calculation of lumen, plaque, and external elastic membrane (EEM) volumes. In the irradiated segments, mean EEM and plaque volumes increased significantly (451+/-128 to 490.9+/-159 mm(3) and 201.2+/-59 to 241.7+/-74 mm(3); P=0.01 and P=0.001, respectively), whereas luminal volume remained unchanged (250.8+/-91 to 249.2+/-102 mm(3); P=NS). The edges demonstrated an increase in mean plaque volume (26.8+/-12 to 32. 6+/-10 mm(3), P=0.0001) and no net change in mean EEM volume (71. 4+/-24 to 70.9+/-24 mm(3), P=NS), resulting in a decrease in mean luminal volume (44.6+/-16 to 38.3+/-16 mm(3), P=0.01).
  
  
  CONCLUSIONS
  A different pattern of remodeling is observed in coronary segments treated with beta-radiation after successful balloon angioplasty. In the irradiated segments, the adaptive increase of EEM volume appears to be the major contributor to the luminal volume at follow-up. Conversely, both edges showed an increase in plaque volume without a net change in EEM volume.
authors.affiliation: Thoraxcenter, Heartcenter, Rotterdam, Dijkzigt Academisch Ziekenhuis Rotterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Sabaté
authors.forename: P W
authors.initials: PW
authors.lastname: Serruys
authors.forename: W J
authors.initials: WJ
authors.lastname: van der Giessen
authors.forename: J M
authors.initials: JM
authors.lastname: Ligthart
authors.forename: V L
authors.initials: VL
authors.lastname: Coen
authors.forename: I P
authors.initials: IP
authors.lastname: Kay
authors.forename: A L
authors.initials: AL
authors.lastname: Gijzel
authors.forename: A J
authors.initials: AJ
authors.lastname: Wardeh
authors.forename: A
authors.initials: A
authors.lastname: den Boer
authors.forename: P C
authors.initials: PC
authors.lastname: Levendag
mesh_terms: D000800:Angioplasty, Balloon; D001610:Beta Particles; D001918:Brachytherapy / Q000379:methods; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology*; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged