title: Angioplasty of obstructed homograft conduits in the right ventricular outflow tract with ultra-noncompliant balloons: assessment of therapeutic efficacy and conduit tears.
abstract: BACKGROUND
  Angioplasty and stent placement in right ventricle-to-pulmonary artery (RV-PA) conduits have been shown to prolong the functional lifespan of a conduit. Safety and efficacy of angioplasty of obstructed RV-PA homografts using ultra-noncompliant (UNC) or ultrahigh-pressure balloons are unknown.
  
  
  RESULTS
  From 2004 to 2012, 70 patients underwent 76 procedures for angioplasty of RV-PA homografts with UNC Atlas balloons. The UNC group was compared with a partially contemporaneous control cohort of 81 patients who underwent 84 angioplasty procedures with conventional balloons. Acute hemodynamic changes after angioplasty of homografts with UNC balloons included significantly reduced RV:Ao pressure ratio (P=0.02) and right ventricular outflow tract gradients (P≤0.001). Balloon waist resolution was more frequently achieved with UNC balloons (P=0.04), and balloon rupture occurred less often (P<0.001). Conduit tears of any severity occurred in 22% of patients overall and were more common in the UNC group (P=0.001). Patients with any conduit tear had significantly greater reduction in their RV:Ao pressure ratio (P<0.001) and right ventricular outflow tract gradient (P=0.004) than those with no tear. There were 4 unconfined tears, all in the UNC group, with no acute decompensations or deaths and only 1 patient who required surgical management.
  
  
  CONCLUSIONS
  RV-PA conduit tears are common in patients undergoing angioplasty, but clinically important tears, which only occurred during UNC angioplasty in this series, were uncommon. UNC balloons can be used to good effect with significant reduction in right ventricular outflow tract gradient and the RV:Ao ratio when compared with conventional balloons.
authors.affiliation: From the Department of Pediatric Cardiology, Children's Hospital Boston, MA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hainstock
authors.forename: Audrey C
authors.initials: AC
authors.lastname: Marshall
authors.forename: James E
authors.initials: JE
authors.lastname: Lock
authors.forename: Doff B
authors.initials: DB
authors.lastname: McElhinney
mesh_terms: D000293:Adolescent; D000792:Angiography; D000800:Angioplasty, Balloon / Q000295:instrumentation* / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D004867:Equipment Design; D004868:Equipment Failure; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D061214:Patient Safety; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult
keywords: angioplasty; conduit; ventricular outflow obstruction