慢性发绀型肺血减少先天性心脏病幼猪模型的建立与病理学观察

Development and pathological observation on a chronic cyanotic porcine model with decreased pulmonary blood flow

目的:采用人工血管肺动脉(PA)-左心房(LA)分流与肺动脉环缩的方法建立慢性发绀型肺血减少先天性心脏病(先心病)幼猪模型。方法:将6～8 w龄幼猪分2组,肺血减少组7只,行人工血管PA-LA分流及PA远端环缩;对照组6只,仅开胸。饲养4 w后行二次手术,评估建模效果。结果:对照组均存活,肺血减少组存活6只。肺血减少组跨肺动脉环缩处收缩压差由(10.33±6.09)mmHg(1 mmHg=0.133 kPa)增至4 w后的(19.67±4.76)mmHg,P=0.011。与对照组比较,肺血减少组动脉血氧饱和度(SaO2)、动脉氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)、血红蛋白含量(Hb)和血细胞比容(Hct)差异均有统计学意义(P<0.05)。2组幼猪肺脏、心脏组织比较有明显的病理学特征差异。结论:应用人工血管PA-LA分流与PA环缩的方法成功建立慢性发绀型肺血减少先心病动物模型,创伤小、可重复性高。

Objective：To create an experimental model of chronic cyanotic piglet model with decreased pulmonary blood flow using pulmonary artery（PA）-left atrial（LA） shunt with pulmonary artery banding,and optimize experimental protocol in order to improve repeatability of this model.Methods：In 7 piglets（6-8 weeks old）,a beveled,5 mm,polytetrafluoroethylene（Gore-Tex） tube graft was anastomosed to the PA and LA,and then surgical pulmonary artery banding was operated（cyanotic model group）.Another 6 piglets underwent sham operations（control group）.After a mean duration of 4 weeks,these piglets underwent secondary procedure.Pulmonary artery pressures were recorded by direct puncture of a pressure-monitoring catheter.Arterial blood gas samples and echocardiogram data were drawn preoperatively and 4 weeks postoperatively.Results：At a mean duration of 4 weeks postoperatively,there were 6 long-term survivors in cyanotic model group.The gradient pressure of pulmonary artery banding in cyanotic model group was increased from（10.33±6.09） mmHg（1 mmHg=0.133 kpa） to（19.67±4.76） mmHg after 4 weeks（P=0.011）.The arterial oxygen saturation（SaO2）,arterial oxygen tension（PaO2）,arterial carbon dioxide tension（PaCO2）,hemoglobin concentration（Hb） and hematocrit value（Hct） were 82.35%,68.73 mmHg,51.83 mmHg,13.82 g/dl and 42.67% in cyanotic model group versus 96.43%,194.08 mmHg,36.9 mmHg,10.98 g/dl and 31.17% in control group,respectively（all P0.05）.There were significant pathologic differences of lung and heart tissue between the two groups.Conclusion：A chronic porcine model of cyanotic congenital heart disease with decreased pulmonary blood flow was successfully established by right-to-left shunting with a PA-to-LA synthetic graft with PA banding.Application of this experimental design may enhance our understanding and possibly influence the treatment of patients having congenital cyanotic heart disease with decreased pulmonary blood flow.