OBJECTIVETo establish an animal model of congenital heart defect with decreased pulmonary blood flow for better understanding the pathophysiology of pulmonary vascular development and related regulatory mechanisms of congenital heart defect with decreased pulmonary blood flow.

METHODOne to two months old pigs were randomly divided into three groups: control group (group C, n = 6) with right chest small incisions induced transient pulmonary blood reduction; light-moderate stenosis groups (group T(1), n = 7): artificial atrial septum defect (ASD) plus controlled pulmonary artery banding to generate a systolic pressure gradient of 20 - 30 mm Hg (1 mm Hg = 0.133 kPa); severe stenosis groups (group T(2), n = 7): similar surgical procedures as group T(1), and controlled pulmonary artery banding to generate a systolic pressure gradient ≥ 30 - 50 mm Hg. 64-slice computed tomography scanning was performed at one month post operation. Arterial blood gas analysis, hemoglobin value, pulmonary vessel, ASD and banding ring diameters and trans-pulmonary artery banding pressure (Trans-PABP) were determined at two months post operation.

RESULTSOne pig died due to tracheal intubation accident in the C group, one pig died due to bowel obstruction in the T(1) group and two pigs died due to acute right heart failure and chronic heart failure respectively in T(2) group. 64-slice CT angiography results showed that aortic diameter of T(1) group was significantly lower than that of C group and banding diameter was significantly lower than aortic diameter in the T(1) and T(2) groups at one month post operation. Two months after operation, the size of ASD were (8.0 ± 0.5) mm and (8.9 ± 1.4) mm (P > 0.05) respectively in the T(1) and T(2) groups after operation. The Trans-PABP was significantly higher in the T(1) and T(2) groups than in C group (P < 0.01), and the Trans-PABP was significantly higher in the T(2) group than in T(1) group (P < 0.01). PaO2 and SaO2 in the T(1) and T(2) groups were significantly lower than those in C group.

CONCLUSIONArtificial atrial septum defect combined pulmonary artery banding procedures could be successfully used to establish model of congenital heart defect with decreased pulmonary blood flow and this model could help to understand the pathophysiology and monitor therapy efficacy for patients with congenital heart defect with decreased pulmonary blood flow.