title: Endovascular stent implantation for the management of postoperative right ventricular outflow tract obstruction: clinical efficacy.
abstract: OBJECTIVE
  Extracardiac conduits between the right ventricle and pulmonary arteries commit patients to multiple reoperations. We reviewed our experience with stent implantation in obstructed conduits.
  
  
  METHODS
  Between 1990 and 1997, stents were implanted across 43 conduits. The median age at procedure was 6 years (0.5-17 years), and the median interval between conduit insertion and stent implantation was 2.4 years (0.3-14 years).
  
  
  RESULTS
  Mean systolic right ventricular pressures and gradients, respectively, decreased from 71 +/- 18 mm Hg and 48 +/- 19 mm Hg before to 48 +/- 15 mm Hg and 19 +/- 13 mm Hg after stent placement. Mean percentage of predicted valve area for body surface area increased from 26% +/- 12% to 48% +/- 17% after stent placement. Fifteen patients underwent a second transcatheter intervention (dilation or additional stent), and 2 patients, a third, allowing further postponement of surgery in 8 patients. One sudden death occurred 2.8 years after stent placement. Surgical conduit replacement has occurred in 20 patients. Body growth was maintained during follow-up. Freedom from surgical reintervention was 86% at 1 year, 72% at 2 years, and 47% at 4 years. Higher right ventricular pressure and gradient before and after stent placement and lower percentage of predicted valve area for body surface area after stent placement were associated with shorter palliation.
  
  
  CONCLUSIONS
  Endovascular stent placement across obstructed conduits is a safe and effective palliation that allows for normal body growth.
authors.affiliation: Departments of Pediatrics and Surgery, Division of Cardiology, and the Variety Club Cardiac Catheterization Laboratories, The Hospital for Sick Children, The University of Toronto School of Medicine, Toronto, Ontario, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Ovaert
authors.forename: C A
authors.initials: CA
authors.lastname: Caldarone
authors.forename: B W
authors.initials: BW
authors.lastname: McCrindle
authors.forename: D
authors.initials: D
authors.lastname: Nykanen
authors.forename: R M
authors.initials: RM
authors.lastname: Freedom
authors.forename: J G
authors.initials: JG
authors.lastname: Coles
authors.forename: W G
authors.initials: WG
authors.lastname: Williams
authors.forename: L N
authors.initials: LN
authors.lastname: Benson
mesh_terms: D006328:Cardiac Catheterization; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D008297:Male; D010166:Palliative Care / Q000379:methods; D011183:Postoperative Complications / Q000601:surgery / Q000628:therapy; D019919:Prosthesis Implantation; D015607:Stents; D013997:Time Factors; D014694:Ventricular Outflow Obstruction / Q000209:etiology / Q000601:surgery / Q000628:therapy*