Histological Changes at Sites of Pulmonary Venous Stenting in a Normal Porcine Model

  • Dr Takeshi Furukawa, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Masahiko Kishiro, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Hideo Fukunaga, Department of Pediatrics, Juntendo Nerima Hospital, Japan
  • Dr Masahiro Ohtsuki, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Ken Takahashi, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Katsumi Akimoto, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Toshiaki Shimizu, Department of Pediatrics, Juntendo University School of Medicine, Japan
  • Dr Shiori Kawasaki, Department of Cardiovascular Surgery, Juntendo University School of Medicine, Japan

    • Objective: The outcome of stent implantation by catheter intervention for pulmonary vein stenosis (PVS) remains poor in children. Meanwhile, use of drug eluting stents (DES) in PVS has never been reported, and its effectiveness remains unknown. Methods: In this study, 3 bare-metal stents (BMS) and sirolimus-eluting stents (SES) each were implanted in one-month-old pigs which were autopsied 8 weeks later to compare restenosis. Results: The extent of neointimal thickness by injury score was significantly less in the SES groups than in the BMS group (injury score 1: SES 0.226 ± 0.031 mm versus BMS 0.351 ± 0.033 mm (P < 0.01); injury score 2: SES 0.609 ± 0.208 mm versus BMS 1.232 ± 0.244 mm (P < 0.01)). Neointimal thickness for injury score 3 did not differ significantly. Pathological findings with BMS showed a confluence of abscessed inflammatory cells around the stent wires as well as granuloma formation around it. Granuloma formation was not seen with SES. Conclusions: Restenosis was significantly reduced in the SES group, suggesting the effectiveness of DES in PVS treatment. Due to the small number of cases in the present study and the considerable spread in injury scores and balloon to vein ratios, future studies with more cases are needed.