产前超声诊断主动脉缩窄的相关指标及其价值研究

Research on relevant factors and the value on prenatal ultrasound diagnosis for coarctation of the aorta

目的探讨产前超声诊断主动脉缩窄(CoA)的相关因素及其应用价值。方法回顾分析2011年1月至2018年7月因右心优势和主动脉弓内径细小而疑诊为CoA并出生的胎儿112例。根据出生后的超声及CT结果分为CoA组(A组)和主动脉弓正常组(B组)。综合分析两组胎儿一般情况和超声资料,筛选与诊断最相关的指标,判断其诊断价值。结果138例胎儿疑诊为CoA,其中有112例选择出生,其中A组59例(52.7%),B组53例(47.3%)。两组间孕周、左室Z值、升主动脉(AAO)内径Z值、主动脉弓峡部Z值、主肺动脉/升主动脉(MPA/AAO)内径比值、动脉导管/峡部内径比值差异有统计学意义(P<0.05)。使用Logistic回归对两组病例的一般资料和超声资料进行分析并筛选出四个指标,单因素ROC曲线选取的截点分别为初次就诊孕周≤34.5周、左室内径Z值<-1.8、峡部Z值<-2.7和MPA/AAO内径比值>1.6。根据截点将人群分组后四因素分类变量ROC曲线下面积可达0.94(95%CI:0.89-0.99)。根据孕周截点将人群分为Ⅰ组(≤34.5周)和Ⅱ组(>34.5周)后再次分析,Ⅰ组右室内径Z值>2.1、MPA/AAO内径比值>1.6,Ⅱ组MPA/AAO内径比值>1.7、动脉导管/峡部内径比值>2.3可作为诊断CoA的重要参考指标。同时,注意一些特征性的超声征象(主动脉弓发育不良、主动脉弓峡部双向血流等)也可协助提高诊断的准确率。结论产前诊断CoA仍存在很大困难,需结合孕周对超声图像和特征进行综合评估,在不同孕周分组中的超声评估指标可能存在差异。

Objective To improve the accuracy of prenatal diagnosis for coarctation of the aorta(CoA)by comparatively analyzing the relevant factors and their application value.Methods Cases of disproportion of ventricles and great vessels were selected between January 2011 and July 2018.Only liveborn fetuses with complete postnatal follow-up were included in the study.One hundred and twelve cases were retrieved and analyzed.According to the postnatal ultrasound and CT results,the patients were divided into gruop A and goup B.Different fetal echocardiography parameters and features were selected to evaluate the diagnostic value.Logistic regression analysis was used to select the best predictors of CoA and optimal cut-offs for these parameters were identified by ROC analysis.Results One hundred and thirty eight fetuses were suspected to be CoA,and 112 of them were born.They included 59 cases(52.9%)with CoA(Group A)and 53 cases(47.3%)without CoA(Group B).There were statistically significant differences between the two groups in gestational age,Z-score of diameter of left ventricle,ascending aorta(AAO)and aortic arch isthmus,main pulmonary artery(MPA)/AAO diameters ratio,and arterial duct/isthmus diameters ratio.The parameters most predictive of postnatal CoA selected by logistic regression and the cut-off values identified by ROC analysis were:gestational age at first diagnosis≤34.5 weeks,Z-score of diameter of left ventricle<-1.8,Z-score of diameter of isthmus<-2.7,MPA/AAO diameters ratio>1.6.AUC yielded by these parameters in combination was 0.94(95%CI:0.89-0.99).The study group were divided into two subgroups by gestational age at first diagnosis.The parameters and cut-off values in subgroups were selected by the same analysis as above:GroupⅠ(≤34.5 weeks),Z-score of diameter of right ventricle>2.1,MPA/AAO diameters ratio>1.6;GroupⅡ(>34.5 weeks),MPA/AAO diameters ratio>1.7,arterial duct/isthmus diameters ratio>2.3.Meanwhile,some ultrasound features(including aortic arch hypoplasia,retrograde blood flow of aortic isthmus)should also be considered to improve diagnostic accuracy.Conclusions Combined with the use of different ultrasound parameters and features at different gestational weeks can improve the accuracy of the prenatal diagnosis of CoA in the right heart dominant fetus.