The Application Of64-slice Computed Tomography In Evaluation The Immature Pulmonary Vascular In The Porcine Model Of Congenital Heart Defect With Decreased Pulmonary Blood FLow

Objective: Using a novel Hybrid method to establish Porcine model of congenital heartdisease with diminutive pulmonary blood, To evaluation the value of64-slice computedtomography in evaluate the immature pulmonary vascular.Methods: Choose twenty piglets with about one to two-month-old,which areexclusively for experiment used. The piglets were randomly divided into threegroups:contrasting-operated group （group S n=6）: Small incisions on the right chest,produced a transient reduction in pulmonary blood; Operation group1（group T₁=7）:Small incisions on the right chest, did artificial room septostomycreation by self-dilatorswhich were delivered into the surface of the right atrium and controlled pulmonaryartery banding to generate a systolic pressure gradient at pressure of20³0mmHg;Operation group2（group T₂=7）: T₂were the same surgical procedures with group1, andcontrolled pulmonary artery banding to generate a systolic pressure gradient at pressureof≥30⁵0mmHg. All three group underwent64-slice spiral CT, cardiac ultrasound,intraoperative probe measurements and histopathological examination. The diameters ofmain pulmonary artery （MPA）, left pulmonary artery （LPA）, right pulmonary artery（RPA）, ascending aorta （AOD） and pulmonary artery banding （BD） that got by using64-slice spiral CT angiography were compared with these diameters that got byechocardiography measurement and intraoperative exploration.We obtained rightmiddle lobe lateral segment size of1.0×0.8×0.8cm³lung tissue from the three groupat thoracotomy, the end of surgery, postoperative February. In the light microscopeobservation of lung tissues, we mainly use the microscope-computer color imagesystem measurement of pulmonary vascular density per unit area of alveolar,arterialratio and media thickness of muscular arteries, the ratio of vascular density and alveolarvascular cross-sectional area and so on.Results:After surgery prompted the size of atrial septal defect in the two experimentalgroups were8.0±0.5mm and8.9±1.4mm （p>0.05）.After two months surgical exploration Trans-PABP by ultrasound measurements was significantly increased from19.1±5.6mmHg to24.1±3.0mmHg in T₁（p <0.01）, and from34.2±3.9mmHg to43.6±6.4mmHg in T₂（p <0.01）. After one month surgical exploration,64-slice computedtomography for the qualitative diagnosis of pulmonary artery is superior toechocardiography （diagnostic sensitivity: the former was91.4%, the later was45.7%）;64-slice computed tomography and surgical exploration had a good correlation forpulmonary artery measurements,.（RPA r=0.91,LPA r=0.86）.In the thoracotomy and atthe end of surgery lung histopathology showed: the diameter of pulmonary arterioleswas not significant difference between T₁, T₂and S group（p>0.05）. After surgerycompleted two months, small artery diameter of lung in T₁was higher than the S group（p <0.05）, the pulmonary artery diameter of T₂group was significantly higher than theS group （p <0.01）; lung arterioles APSC in T₁was lower than the control group （p <0.05）, pulmonary artery APSC in T₂was also lower than the S group （p <0.01）.Conclusion:1. This study may successfully establish the porcine model of congenital heart defectwith decreased pulmonary flood flow by these methods of balloon atrial septal stomaand pulmonary artery banding.2.64-slice spiral CT in determining the proximal pulmonary vascular development maysuperior to cardiac ultrasound which is in a more traditional location, its exploration andintraoperative pulmonary artery diameter measurements obtain good correlationvalues.It also can be used to evaluate the pulmonary form of pulmonary blood sourcesand suitable for complex congenital heart disease in children pulmonary vascularmorphology assessment.3.64-slice spiral CT by which in determining the distal lung vascular developmentdistal pulmonary arteries showed sparse textures, consistent with the morphologicalchanges, has high practicability and accuracy in assessing the distal pulmonary vasculardevelopment.