title: Significance of low peak Doppler velocity in the proximal sano conduit in hypoplastic left heart syndrome.
abstract: BACKGROUND
  The Sano modification of the Norwood operation is a well-established first step palliation for hypoplastic left heart syndrome (HLHS). Theoretically, the first point of resistance to pulmonary flow should be in the proximal Sano, generating high Doppler flow velocity. Paradoxically, however, some patients have low gradients in the proximal Sano conduit. The objective of this study was to determine the hemodynamic and anatomic significance of low proximal Sano Doppler flow velocity and its clinical implications.
  
  
  METHODS
  Doppler-derived peak gradients in the proximal Sano conduits were measured in HLHS patients after Norwood-Sano surgery over a 4-year period and confirmed by cardiac catheterization within 2 to 4 weeks. Clinical outcomes of patients with proximal Sano gradients of 30 mm Hg or less (group 1) were compared with patients whose gradient was greater than 30 mm Hg (group 2).
  
  
  RESULTS
  Of the 53 patients, 21 (40%) belonged to group 1. Patients in group 1 had smaller ostial right and left pulmonary artery (PA) diameter (3.2 ± 1.2 mm versus 4.5 ± 1.8 mm, p = 0.03; and 3.4 ± 1.2 mm versus 5.6 ± 2.1 mm, p = 0.01) when compared with patients in group 2. Patients (7 of 10) who needed either balloon angioplasty of a distal Sano or proximal branch PA were from group 1 (p = 0.01). Patients in group 1 had higher rates of unintended PA interventions (33% versus 9%) and complications (48% versus 16%) compared with group 2.
  
  
  CONCLUSIONS
  Low peak Doppler flow velocity in the proximal Sano correlates with the presence of either distal Sano stenosis or proximal branch PA stenosis. These patients require close follow-up in the interstage period and may need earlier intervention.
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois; Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee.
authors.forename: Shyam K
authors.initials: SK
authors.lastname: Sathanandam
authors.affiliation: Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee. Electronic address: rphill15@uthsc.edu.
authors.forename: Ranjit
authors.initials: R
authors.lastname: Philip
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: Andrew
authors.initials: A
authors.lastname: Van Bergen
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: David A
authors.initials: DA
authors.lastname: Roberson
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: Wei
authors.initials: W
authors.lastname: Cui
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: Michel N
authors.initials: MN
authors.lastname: Ilbawi
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Javois
authors.affiliation: The Heart Institute for Children, Advocate Hope Children's Hospital, Oak Lawn, Illinois.
authors.forename: Tarek S
authors.initials: TS
authors.lastname: Husayni
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D005260:Female; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000503:physiopathology / Q000601:surgery*; D007231:Infant, Newborn; D008297:Male; D012189:Retrospective Studies