Objectives: Postoperative left pulmonary artery (PA) or bronchus compression occasionally follows narrowing of the retroaortic space after the Norwood procedure. We examined hypoplastic left heart syndrome (HLHS)-specific anatomical malformations and hypothesized that a long main pulmonary arterial trunk might contribute to a larger retroaortic space. In this study, we introduced a modified Norwood procedure [pulmonary artery trunk-saving method (PATS)] and evaluated the results.
Methods: HLHS-specific anatomical malformations were examined using computed tomographic data from 23 consecutive patients who underwent bilateral pulmonary banding. Fourteen patients had HLHS or associated conditions (Group H), and 9 patients had other complex cardiac defects and underwent biventricular repair (Group B). Five consecutive HLHS patients underwent PATS as a modified Norwood operation, and 6 controls underwent a conventional Norwood procedure. We used computed tomography to measure the lengths of the aorta and PA and the angle of both pulmonary branches to evaluate the effect of PATS.
Results: Preoperative examination confirmed HLHS-specific right PA branching adjacent to the pulmonary valve and a trend towards a shorter main pulmonary arterial trunk with the conventional Norwood procedure. Also, both right and left pulmonary arterial branching from the dorsal aspect of the main pulmonary arterial trunk and the PA branch angle were minimal in HLHS patients. Postoperative data showed the retroaortic space behind the reconstructed neoaorta was significantly wider in PATS patients than in conventional Norwood patients. Longitudinal measurements (between the aortic arch and pulmonary valve) and sagittal measurements (ascending aorta to descending aorta) were larger in PATS patients, and no left PA or airway obstruction was observed following PATS.
Conclusions: PATS resulted in a wider aortopulmonary space without left pulmonary arterial stenosis or bronchus obstruction. HLHS-specific anatomical malformations suggested that PATS may avoid extrinsic compression of the left PA and bronchus by the neoaorta and can be an alternative for HLHS patients.