ABSTRACT
Objective Artificial atrial septum defect combining pulmonary artery banding to create a model of congenital heart defect with decreased pulmonary blood flow to explore the morphological changes of immature pulmonary vascular. Methods Choose twenty piglets with about one to two-month-old, which are exclusively for experiment used. The piglets were randomly divided into three groups: normal control group (group C, n = 6), Small incisions on the right chest, produced a transient reduction in pulmonary blood; low-medium pulmonary artery stenosis groups ( group T1, n = 7 ) : Did artificial room septostomy creation by self-dilators which were delivered into the surface of the right atrium and controlled Systolic trans pulmonary artery banding pressure (Trans-PABP) at pressure of 20 - 30 mmHg; severe pulmonary artery stenosis groups ( group T2, n = 7): T2 were the same surgical procedures with group T1 ,and controlled Trans-PABP ≥ 30 -50 mmHg. Monitored ultrasound after operation , carried out 64-slice computed tomography scanning after one month, to measure the proximal vessel diameter and TransPABP , after two month surgical exploration on the left chest. When the animals were sacrificed, the heart and lung tissue was cut to measure atrial septal defect, pulmonary artery and the banding diameter. By weihgt elastic fiber and van Cieson staining to observe the morphological pathological changes, three groups took lung tissue with right middle lobe lateral segment about 1.0 cm × 0.8 cm × 0.8cm at the end of surgery and 2-months after operation respectively. Results The models were all successfully in the survival animal of the two test groups. One pig died from tracheal intubation accident in the C group, there was one case died due to bowel obstruction in the T1 group, And there were two cases died result from acute right heart failure and chronic heart failure respectively in T2 group. 64-slice CT angiography showed that BD was significantly lower than the AOD in the two test groups, the proximal pulmonary vascular expansion result from stenosis, distal pulmonary vascular scarce. Histopathology showed that the pulmonary artery inside diameter of T1 and T2 was significantly higher than group C(P ＜0. 05,P ＜ 0.01), and the NAPSC of two experimental groups were significantly lower than group C 2-month after operation( P ＜0.01).Conclusion This type of Piglet model is closer to clinical pathological and physiological ,64-slice spiral CT combined with lung histopathology observed for the evaluation of pulmonary vascular hypoplasia is a reliable method. Tunica media of pulmonary arterioles hypoplasia with the number reducing, with pulmonary artery banding increased,the degree of pulmonary arterioles hypoplasia gradually increased.
ABSTRACT
Objetivo - Avaliar o resultado pós-operatório imediato de crianças portadoras de cardiopatias congênitas com hipofluxo pulmonar, submetidas à derivaçäo sistêmico-pulmonar. Casuística e Métodos - Sessenta e quatro pacientes, 30 (46,8%) do sexo masculino, com idades entre 1 dia e 17 anos, divididos em: grupo I, 13 (20,3%) pacientes submetidos à operaçäo de Blalock-Taussig (B-T) clássica; grupo II, 46 (71,8%) pacientes submetidos à B-T modificada, sendo usados 2 tipos de enxertos, polytetrafluoroetylene (PTFE) em 34 casos e veia umbilical em 12; grupo III, em 5 (7,8%) pacientes submetidos à derivaçäo central com emprego de 3 tipos de enxertos, PTFE em 3, veia umbilical em 1 e artéria mamária bovina em 1. Os procedimentos associados foram ligadura do canal arterial persistente em 2 casos, ligadura de artérias brônquicas em 3, valvotomia pulmonar em 3, ampliaçäo de via de saída do ventrículo direito em 3 e apliaçäo de estenose de artéria pulmonar em outros 2 casos. Resultados - No grupo I houve 4 (30,7%) casos com obstruçäo da derivaçäo, tendo sido 2 reoperados, com mortalidade de 30,7%. No grupo II houve 4 (8,6%) casos com obstruçäo e 2 reoperaçöes com mortalidade de 15,2% (7 casos) e no grupo III houve 1 (20%) de obstruçäo e mortalidade de 80% (4 casos). A mortalidade relacionada exclusivamente à derivaçäo foi de 15,3%, 8,6% e 40% respectivamente. Conclusäo - A operaçäo de B-T modificada, realizada com maior freqüência, apresentou menor índice de obstruçäo e menor mortalidade, sendo recomendada como primeira escolha