title: Clinical and stent-related outcomes after transcatheter or operative placement of bare-metal stents in the ventricular septum or subvalvar systemic outflow tract.
abstract: BACKGROUND
  Stenting of the systemic ventricular outflow tract and creation or enlargement of a ventricular septal defect using stents are potential therapeutic options in rare patients with congenital heart disease who develop significant ventricular hypertension due to outflow obstruction. These stents may be at increased risk of fracture because of exposure to cyclic compressive stresses. The objective of this study was to evaluate the safety and efficacy of this intervention and to determine the incidence of stent fracture and other adverse outcomes after placement of intraventricular or interventricular stents for this indication.
  
  
  RESULTS
  Between 1992 and 2010, 27 patients underwent bare-metal stent placement in the ventricular septum or subvalvar systemic outflow tract, using 1 of the following 3 delivery approaches: (1) percutaneous (n=18), (2) intraoperative (n=8), and (3) hybrid (n=1). The median ventricular-to-aortic systolic pressure ratio decreased from 1.7 (1.3-2.6) to 1.1 (0.9-1.8) (P<0.001). Survival free from surgical reintervention for outflow obstruction was 92% at 1 year and 66% at 3 years. Stent fracture was diagnosed in 11 patients (41%) a median of 2.6 years (0.03-7.8 years) after stent placement and was always associated with recurrent obstruction. Survival free from diagnosis of stent fracture was 84% at 1 year and 73% at 3 years. Other adverse events included complete heart block (n=2) and increased atrioventricular valve regurgitation requiring surgical intervention (n=2).
  
  
  CONCLUSIONS
  Transcatheter, intraoperative, or hybrid stenting of the ventricular septum or systemic outflow tract is feasible and effective in the short term. Stent fractures were common during follow-up and associated with recurrent obstruction.
authors.affiliation: Department of Cardiology and Department of Cardiac Surgery, Children's Hospital Boston, 300 Longwood Ave, Boston, MA 02115, USA. diego.porras@cardio.chboston.org
authors.forename: Diego
authors.initials: D
authors.lastname: Porras
authors.forename: Doff B
authors.initials: DB
authors.lastname: McElhinney
authors.forename: Pedro
authors.initials: P
authors.lastname: Del Nido
authors.forename: James E
authors.initials: JE
authors.lastname: Lock
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Meadows
authors.forename: Audrey C
authors.initials: AC
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000328:Adult; D006328:Cardiac Catheterization / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D019245:Compressive Strength; D017023:Coronary Angiography; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008670:Metals; D008875:Middle Aged; D011475:Prosthesis Failure; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D013314:Stress, Mechanical; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D054088:Ventricular Septum / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery*; D055815:Young Adult
chemical_list: D008670:Metals