title: Histological findings after angioplasty using conventional balloon, radiofrequency thermal balloon, and stent for experimental aortic coarctation.
abstract: BACKGROUND
  Use of balloon angioplasty or stent implantation has been reported to be effective in relieving coarctation of the aorta. However, restenosis frequently occurs after balloon angioplasty for native aortic coarctation in small infants, and sometimes develops after stent implantation because of vessel growth. The causes of restenosis remain uncertain. The purpose of this study was to assess the histologic differences in vascular responses to angioplasty using conventional balloon, radiofrequency thermal balloon (RFTB), or stent for experimental aortic coarctation.
  
  
  METHODS
  The authors surgically created an aortic coarctation model using 14 puppies. Angioplasty using conventional balloon, RFTB, or stent was performed 1 month after the initial operation. At the acute or chronic phase after angioplasty, the animals were killed and histologic studies were performed.
  
  
  RESULTS
  More vascular injuries were noted in the specimens from animals undergoing conventional angioplasty than in those with RFTB or stent. However, neointimal hyperplasia was seen more often after RFTB or stent because of the proliferation of smooth muscle cells from the tunica media, caused by secretion of growth factors. Apoptosis reached a peak 1-2 weeks after angioplasty, regardless of the type of intervention.
  
  
  CONCLUSIONS
  The authors conclude that angioplasty with RFTB or stent can provide relatively small injuries in the vessel wall for aortic coarctation, but care must be taken to prevent restenosis caused by intimal hyperplasia, because neointima hyperplasia is more frequent after RFTB or stent.
authors.affiliation: Department of Pediatrics, Juntendo University School of Medicine, Tokyo, Japan. mohkubo@med.juntendo.ac.jp
authors.forename: Mataichi
authors.initials: M
authors.lastname: Ohkubo
authors.forename: Ken
authors.initials: K
authors.lastname: Takahashi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kishiro
authors.forename: Katsumi
authors.initials: K
authors.lastname: Akimoto
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamashiro
mesh_terms: D000800:Angioplasty, Balloon / Q000379:methods*; D000818:Animals; D001017:Aortic Coarctation / Q000473:pathology* / Q000628:therapy*; D017209:Apoptosis; D004285:Dogs; D019332:Endothelin-1 / Q000097:blood; D012008:Recurrence; D015607:Stents; D017539:Tunica Intima / Q000473:pathology
chemical_list: D019332:Endothelin-1