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Objective To create an experimental model of cyanotic congenital heart defect with decreased pulmonary blood flow using a novel hybrid method. Methods A model of congenital heart defect with decreased pulmonary blood flow and chronic cyanosis was produced surgically in eight piglets (mean, 2 mo old). An artificial atrial septal defect was created followed by pulmonary artery banding to generate a systolic pressure gradient at 2 mo of ≥50 mm Hg (cyanotic group). Another eight piglets underwent a sham operation (control group). Results There were six long-term survivors in the cyanotic group. At a mean duration of 2 mo following the hybrid procedure, the resting gradient across the pulmonary artery band was 53.7 mm Hg. The Qp/Qs reached 0.54:1. The arterial oxygen tension, arterial oxygen saturation, hematocrit, and hemoglobin concentration were 52.9 mm Hg, 85.6%, 49.8%, and 16.6 g/dL in the cyanotic group versus 118.0 mm Hg, 98.0%, 37.9%, and 12.2 g/dL in the control group, respectively (all P Conclusions A porcine model of cyanotic congenital heart defect with decreased pulmonary blood flow was established by a hybrid method. Application of this experimental design may enhance our understanding and possibly influence the treatment of patients who have cyanotic heart disease with decreased pulmonary blood flow.

Congenital heart defects with intractable hypoplasia of the pulmonary arteries without intercourse or with intercourse stenosis is unsuitable for surgical correction or regular palliative procedures. We reported our experience with combined palliative procedures for congenital heart defects with intractable hypoplasia pulmonary arteries.From 2001 to 2012, a total of 41 patients with cyanotic congenital heart defects and intractable hypoplasia of the pulmonary arteries underwent surgical procedures. From among them, 31 patients had pulmonary atresia with ventricular septal defect (VSD) and the other 10 cases had complicated congenital heart defects with pulmonary stenosis. Different kinds of palliative procedures were performed according to the morphology of the right and left pulmonary arteries in every patient. If the pulmonary artery was well developed, a Glenn procedure was performed. A modified Blalock-Taussig shunt or modified Waterston shunt was performed if pulmonary arteries were hypoplastic. If the pulmonary arteries were severely hypoplastic, a Melbourne shunt was performed. Systemic pulmonary artery shunts were performed bilaterally in 25 cases. A systemic-pulmonary shunt was performed on one side and a Glenn procedure was performed contralaterally in 16 cases. Major aortopulmonary collateral arteries were unifocalized in six cases, ligated in two cases and interventionally embolized in two cases. There was one early death because of cardiac arrest and the hospital mortality was 2.4%.Five patients suffered from postoperative low cardiac output syndrome, three had perfusion of the lungs, and two pulmonary infections. Systemic pulmonary shunts were repeated after the original operation in three cases due to the occlusion of conduits. The mean follow-up time was 25 months. The pre- and the post-operation left pulmonary indices were (8.13 ± 3.68) vs. (14.9 ± 6.21) mm(2)/m(2). The pre- and post-operation right pulmonary indices were (12.7 ± 8.13) vs. (17.7 ± 7.78) mm(2)/m(2). The pre- and post-operational pulmonary indices were (20.87 ± 9.43) vs. (32.6 ± 11.7) mm(2)/m(2). They were all significantly increased (P0.001). The diameter of the pulmonary artery increased after the modified Blalock-Taussig shunt ((5.51 ± 0.94) mm(2)/m(2) pre-operation vs. (7.01 ± 1.97) mm(2)/m(2) post-operation), the modified Waterston shunt ((5.70 ± 3.96) mm(2)/m(2) pre-operation vs. (9.17 ± 3.62) mm(2)/m(2) post-operation) and the Melbourne shunt ((2.17 ± 0.41) mm(2)/m(2) pre-operation vs. (7.35 ± 2.49) mm(2)/m(2) post-operation) (all P0.05). Bilateral pulmonary arteries developed well as compared to their pre-operation development. Hemoglobin decreased from (194 ± 27) to (174 ± 24) g/L (P0.05) and peripheral oxygen saturation increased from (65 ± 11)% to (84 ± 6)% (P0.001). During the follow-up of 27 to 49 months, ultimate complete repair was performed in four cases and one patient underwent a Glenn procedure.The procedures should be considered on a case to case basis in patients having hypoplasia of the pulmonary arteries with cyanotic congenital heart defects. Combined palliative operations could be an adequate strategic treatment.

To compare the effect of different antegrade pulmonary blood flow on the further development of pulmonary artery after Glenn procedure in cyanotic congenital heart defects (CHD) patients.Between October 2000 and December 2006, 132 CHD patients with decreased pulmonary artery blood flow underwent bidirectional Glenn shunt, among them 18 patients received intraoperative lung biopsy. Patients were divided into two groups according to their different sources of antegrade pulmonary blood flow: antegrade arterial blood flow group (n = 33) and antegrade venous blood flow group (n = 99). The percutaneous oxygen saturation (SpO2), hemoglobin (Hb) concentration, and hemotocrit (Hct) value were examined and recorded before and after operation. The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured with two-dimensional echocardiography and the results were used to calculate the pulmonary artery index (PAI). The method of half-quantitative morphometric technique and an image analyzer were used to measure the following indicators of pulmonary microvessels: the percentage of media thickness (MT%), the percentage of media section area (MS%), vascular numbers of per square centimeter (VPSC), and mean alveolar number (MAN).Before the operation, obvious cyanosis was found in both groups, while SpO2, Hct, and Hb were not significantly different (P0.05). LPA, RPA, and PAI were not significantly different between two groups (P0.05). The MT% and MS% in antegrade venous blood flow group were significantly less than those in antegrade arterial blood flow group (P0.05), but VPSC and MAN were not significantly different (P0.05). After Glenn procedure, hypoxia and cyanosis were remarkably improved in both two groups. There was a significantly negative correlation between SpO2 and Hct (r = -0.49, P0.01) or Hb (r = -0.196, P0.01 ). The PAI increased by 22% in antegrade arterial blood flow group and 44% in antegrade venous blood flow group (P0.05). The diameters of LPA and RPA in antegrade venous blood flow group were significantly larger than those in antegrade arterial blood flow group (P0.05) and the growth of RPA in antegrade arterial blood flow group was not significant.A better pulmonary artery growth occurs in the patients of pulmonary stenosis after Glenn shunt than in those of pulmonary atresia, and it contributes to an earlier completion of Fontan procedure.

To investigate the relationship between pulmonary pathological features and clinical physiology of congenital heart defects (CHD) with decreased pulmonary artery blood flow.Between July 2001 and May 2006, 18 patients with CHD with decreased pulmonary artery blood flow undergoing palliative or definitive repair and having lung biopsy intraoperatively were enrolled in this study. The patients' age was 0.4 - 8.0 years, and body weight was 6.0 - 20.0 kg. The method of semi-quantitative morphometric technique and an image analyzer were applied to measure the following indices of pulmonary microvessels: the percentage of media thickness (MT%), the percentage of media section area (MS%) and numbers of microvessels per square centimeter (VPSC). The diameters of left pulmonary artery (LPA) and right pulmonary artery (RPA) were measured with two-dimensional echocardiography. The percutaneous oxygen saturation (SpO(2)), hemoglobin concentration (HB) and hematocrit value (HCT) were examined and recorded preoperatively.There was a significant negative correlation between SpO(2) and HCT or Hb (R(2) = 0.4914, P = 0.001 and R(2) = 0.5505, P0.001), the variation trend of these three variables was linked. There was a negative correlation between SpO(2) and the body weight (R(2) = 0.2208, P = 0.049), which is in accordance with clinical features of aggravated process of cyanosis and hypoxia. The morphological observation of lung biopsy specimens indicated that most of peripheral pulmonary arteries were distended, irregular and their walls were uneven, and "lake" type of pulmonary AV malformations were observed. There was a positive correlation between VPSC and the body weight or BSA (R(2) = 0.5472, P0.001 and R(2) = 0.5233, P = 0.001). There was a significant correlation between VPSC and LPA or RPA (R(2) = 0.4312, P = 0.003 and R(2) = 0.2463, P = 0.036). It was shown that the diameter of central pulmonary arteries could be a reflection of peripheral pulmonary artery growth. The diameter of LPA also correlated with the diameter of RPA (R(2) = 0.286, P = 0.022).For patients with congenital heart defects with decreased pulmonary blood flow, the pulmonary pathological changes are the bases of their clinical physiologic features. It is suggested that they should be treated in their earlier stage of life.