肺血少型先天性心脏病肺血管病理变化及临床病理生理关系

目的 分析肺血少型先天性心脏病肺血管的病理特点及其与临床病理生理的关系,为判断病情进展和手术时机提供一定的依据.方法 选择2001年7月至2006年5月行姑息或矫治术并有术中肺活检的18例肺血少型先天性心脏病患儿.年龄0.4～8.0岁,体重6.0～20.0 kg.光镜下形态半定量测量肺细小动脉平均中膜厚度百分比(MT%)、平均中膜面积百分比(MS%)、单位面积肺小血管数目(VPSC)、单位面积肺泡数(MAN).临床资料包括超声心动图测量左、右肺动脉(LPA和BPA)直径,近红外线探头测量经皮血氧饱和度(SpO2),检测红细胞压积(HCT)和血红蛋白浓度(HB),利用直线回归分析病理指标与临床指标之间的相关关系.结果 相关性分析发现,SpO2与HB、HCT存在显著的负相关关系(R2=0.4914,P=0.001和R2=0.5505,P＜0.001),三者的变化相互关联;SpO2与体重之间存在显著的负相关关系(R2=0.2208,P=0.049),表现为SpO2逐渐降低和继发性红细胞增多症逐渐加重,说明紫绀缺氧在肺血少型先天性心脏病中呈一慢性加重的过程;病理观察结果显示,肺小动脉管腔扩大,形状不规则,多数呈"湖泊状"样改变,有动静脉吻合形成.VPSC与体重和体表面积(BSA)之间存在显著的正相关关系(R2=0.5472,P＜0.001和R2=0.5233,P=0.001),VPSC与超声测量的LPA、RPA直径之间存在显著的正相关关系(R2=0.4312,P=0.003和R2=0.2463,P=0.036).LPA和RPA直径之间也存在正相关关系(R2=0.286,P=0.022),说明超声测量的中央肺动脉径值能够反映外周肺小血管的发育情况.结论 通过病理与临床指标相结合进行分析,初步发现肺血少型先天性心脏病临床病理生理变化是以肺血管的特殊病理改变为基础的,对这类患儿需要尽早手术治疗.

Relationship between clinical pathophysiology and pulmonary pathology in patients with congenital heart defects and decreased pulmonary artery blood flow

Objective To investigate the relationship between pulmonary pathological features and clinical physiology of congenital heart defects (CHD) with decreased pulmonary artery blood flow.Methods 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 microveszels: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 (SpO2),hemoglobin concentration (HB) and hematocrit value (HCT) were examined and recorded preoperatively.Results There was a significant negative correlation between SpO2 and HCT or lib (R2=0.4914,P=0.001 and R2=0.5505,P ＜0.001),the variation trend of these three variables was linked.There was a negative correlation between SpO2 and the body weight (R2=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 (R2=0.5472,P ＜0.001 and R2=0.5233,P=0.001).There was a significant correlation between VPSC and LPA or RPA (R2=0.4312,P=0.003 and R2=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 (R2=0.286,P=0.022).Conclusions 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.