1002-85 Utility of Unique Projections in Dynamic Transthoracic Three-Dimensional Echocardiography in the Pre- and Post-Operative Delineation of Lesions Associated with Tetralogy of Fallot in Neonates and Infants

Abstract

Management of tetralogy of Fallot (TOF) is influenced by the size and position of the ventricular septal defects (VSD) and the size and magnitude of infundibular, and pulmonary annular and arterial obwtruction. Three dimensional (3D) visualization may provide valuable information on these complex lesions and relations to guide gatheter and surgical interventions in TOF. To assess this, we performed 3D Echo (3DE) in 33 neonates and infants with TOF. In 8 pts additional post-operative studies were acquired. Using 5 or 7.5 MHz transducers placed within a rotational or fan-like scanning device positioned on the chest wall or subcostal position, 2DE images were obtained every two degrees over a span of 180 or 90 degrees with ECG and respiration gating. These data then underwent reformatting, and segmentation, and dynamic 3DE reconstructions derived. Optimal 3DE studies were obtained in all. Based on the experience in these 36 pts, we were able to define specific 3D projections that yielded more detailed or additional information compared to 2DE. These new 3D cuts-ections allowed us to delineate the relative size and degree of malalignment of the VSD, their spatial orientations and relations, morphology of the infundi-bulum, the internal caliber and continuity with the proximal pulmonary arteries, and pulmonic valve morphology and annular size in a reliable manner. Besides defining these abnormalities, 3DE yielded unique en face views of the VSD, and coronal and cylindrical display of the infundi-bulum and pulmonary arteries, not available in 2DE. In the 8 post-op studies, 3DE depicted the geometry and relative size of the reconstructed outflow tract, and continuity to the pulmonary arteries and the integrity of VSD patches. Overall, 3DE was superior in portraying the functional morphology of lesions associated with TOF both pre- and post-operatively. We conclude that dynamic 3DE, easily performed by the transthoracic approach, provides important spatial information that could be valuable in planning catheter and surgical interventions in TOF.