Extracardiac Conduit Reconstruction Of Right Ventricular Outflow Tract Flow Field Visualization

BackgroundThe lesions that affect congenital heart disease have well been recognized to be neither concentrated primarily on or to be associated with the pulmonary circulation. At present, reconstruction of the right ventricular outflow tract (RVOT) with cryopreserved valved homograft conduits was one of the most important means for the surgical management of congenital heart disease. In vitro pulsatile and steady flow visualization focused formerly on the systemic circulation, however, tended presently to those normal and diseased pulmonary artery, pulmonary valve and Fontan operation instead. Tracing and laser Doppler anemometry measurements have been regarded as main methods for internal qualitative and quantitative studies. As to the best of our current knowledge, in vivo Doppler echocardiographic flow visualization was wanting in qualitative analysis for RVOT reconstruction with valved or non-valved extracardiac conduits, while the in vitro pulsatile and steady flow visualization studies have not been reported.Subjects and methodsA simplified pulmonary pulse duplicator system was set up according to RVOT reconstruction with valved homograft extracardiac conduit in cardiac surgery. Both qualitative and quantitative pulsatile studies were employed on models of normal pulmonary and pulmonary artery atresia with RVOT reconstruction using various extracardiac conduits. The pulse duplicator system was slightly reequiped, and a steady circuit was finished with the right atrium model removed, and steady flow source joined, when driven with a DOB10 model monophase motor. Steady flow field of RVOT reconstruction with normal pulmonary valved homograft conduit was observed.Eleven patients with congenital transposition of the great arteries (TGA) or double outlet right ventricle accompanied with ventricular septal defect and pulmonary stenosis were consecutively selected in in vivo study. All patients of the group had indication for Rastelli operation. The procedures, of which intracardiac baffle with Gore-Tex and extracardiac conduit with -196 ℃ cryopreserved aortic valved homograft^TM, were performed with traditional hypothermic cardiopulmonary bypass. Proximal anastomosis to the right ventricle was made in an end-to-side fashion, and distal to the main pulmonary artery in an end-to-end fashion with its proximal extremity sutured. Echocardiographic flow mapping and parameters were measured both pre- and postoperatively, and the flow patterns of the right ventricle, pulmonary artery, and extracardiac conduit were visualized.