The RV-PA conduit stimulates better growth of the pulmonary arteries in hypoptastic left heart syndrome

Objective: This retrospective study compared the size of the central pulmonary arteries in patients with hypoplastic left heart syndrome (HLHS) following either a classical Norwood or Norwood procedure with a right ventricle to pulmonary artery (RV-PA) conduit. Methods: Between May 2001 and May 2003, 30 patients with HLHS underwent cardiac catheterization prior to stage 11 palliation. Patients were initially palliated with a classical Norwood (Classical group, n=18) or Norwood procedure with RV-PA conduit (RV-PA group; n=12). Indexed maximum and minimum diameters of the LPA and RPA were measured using the McGoon ratio. Cardiac catheterisation was performed at a median age of 4.0 months. There was no difference in the time interval to catheterisation (P=0.13), Qp:Qs (P=0.41) or median haemoglobin (P=0.42) between the groups. Results: The combined PA diameter was (larger in the RV-PA group (B) than the classical group (A) (1.99 +/- 0.38 versus 1.630 +/-.29, P<0.05). There were marked differences in the relative size of the pulmonary arteries between the two groups. In RV-PA patients, the LPA and RPA sizes were comparable (0.99 +/- 0.22 versus 1.00 +/- 0.31, P=1.00) whereas, in the classical group, the LPA was smaller than the RPA (0.75 +/- 0.15 versus 0.88 +/- 0.17, P<0.05). Both techniques were also associated with discrete PA stenoses at the site of shunt insertion. Stenoses were more severe in RV-PA group (RV-PA), causing a 42 +/- 16% reduction in the combined PA diameter compared with a 28 +/- 18% reduction in Classical group (classical) (P<0.05). Conclusions: The Norwood procedure with RV-PA conduit is associated with better and more evenly distributed central pulmonary artery growth. Nevertheless, it is also associated with central PA stenoses, which may require subsequent reconstruction. (c) 2005 Elsevier B.V. All rights reserved.