title: Balloon dilation of pulmonary valve stenosis in infants less than 3 kg: a 20-year experience.
abstract: OBJECTIVE
  This study focused on the anatomical features and outcomes of percutaneous pulmonary valve balloon dilation (PVD) in newborns < or = 3 kg in weight.
  
  
  BACKGROUND
  Although PVD is the treatment of choice for isolated pulmonary valve stenosis, there are no studies detailing technical, anatomical, and outcome variables in the smallest of infants undergoing the procedure.
  
  
  METHODS
  A retrospective, consecutive review of all initial and follow-up echocardiograms, catheterization data, cineangiograms, and surgical records of all neonates less than 3 kg.
  
  
  RESULTS
  Fifty infants underwent 55 PVD's, median age 7 days and weight 2.7 kg. Congestive heart failure and/or cyanosis were present in 55%, 46% prostaglandin dependent, with 28% having a hypoplastic right ventricle. The pulmonary valve diameter median z-score was -2.6, (range -5.8 to 1.2, P < 0.0001 vs. normal). The procedure was accomplished in all but one child, using a balloon to annulus ratio of 1.3 (range 1.1 to 1.7). There was a reduction in both the peak right ventricular systolic pressure (P < 0.0001) and outflow gradient (P < 0.0001). There was no procedure related mortality, although six children died in long-term follow-up (14%). Reintervention was necessary in 15 infants within 8 months of the procedure. Pulmonary regurgitation, present in 36% after the procedure, showed a gradual increase over time while outflow gradients decreased and valve annular dimensions increased toward normal.
  
  
  CONCLUSIONS
  In infants < or = 3 kg, PVD is safe and effective. A large proportion remains free from surgery (76% at 10 years). Small valve annular dimensions show catch up growth with time.
authors.affiliation: The Department of Pediatrics, Division of Cardiology, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada M5G 1X8.
authors.forename: Tevfik
authors.initials: T
authors.lastname: Karagoz
authors.forename: Kentaro
authors.initials: K
authors.lastname: Asoh
authors.forename: Edward
authors.initials: E
authors.lastname: Hickey
authors.forename: Rajiv
authors.initials: R
authors.lastname: Chaturvedi
authors.forename: Kyong-Jin
authors.initials: KJ
authors.lastname: Lee
authors.forename: David
authors.initials: D
authors.lastname: Nykanen
authors.forename: Lee
authors.initials: L
authors.lastname: Benson
mesh_terms: D000015:Abnormalities, Multiple; D001724:Birth Weight; D006328:Cardiac Catheterization; D002404:Catheterization / Q000009:adverse effects / Q000401:mortality; D002932:Cineangiography; D003326:Coronary Circulation; D004452:Echocardiography; D005260:Female; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D011665:Pulmonary Valve Insufficiency / Q000209:etiology; D011666:Pulmonary Valve Stenosis / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D017725:Ventricular Pressure