Pathological features of pulmonary arteries in a porcine model of cyanotic congenital heart defect with decreased pulmonary blood flow / 临床与实验病理学杂志

ABSTRACT

Purpose Using quantitative morphometric techniques, To analyzse the developmental characteristics of pulmonary arterial and alveolar with a porcine model of cyanotic congenital heart defect with decreased pulmonary blood flow that we had established. Methods Lung biopsy specimens were taken from animals of control ( C) and cyanosis ( D) groups and than sectioned and stained. The morphological observation and the method of half-quantitative morphometric technique were applied to measure the following char-acteristicsthe media thickness ( MT) and the percentage of media thickness ( MT%) , the media section area ( MS%) and the per-centage of media section area ( MS) , the numbers of micro-arteries per square centimeter ( APSC) . In addition, we calculated the ratio of CMA, PMA and NMA in the same section of lung biopsy specimens. Results There showed universally distended, irregular and thin-walled vessels in the lung biopsy specimens of group D under the light microscope. There was an increased number of pulmonary arteries whose media were hypoplastic. The MT, MT% and MS, MS% in group D were significantly less than those of group C ( all P0. 05). Electron microscopy revealed endothelial swell and irregularity, a thinned basement membrane, a disorganized or disrupted elastic fibers layer. The smooth muscle of vascular media shrunk. In addition to these, other changes included the mitochon-drion vacuolization, a diminished cellular organelle and type Ⅱ alveolar epithelial hyperplasia. Conclusion The pulmonary vessels are evidently hypoplastic or degenerated in cyanotic congenital heart defect with decreased pulmonary blood flow, and the function is thought to be influenced by the morphological changes. To promote the pulmonary artery growth and improve this pathophysiological state, it is critical to increase the pulmonary blood flow.