Persistent Left Superior Vena Cava: Why is Prenatal Diagnosis Important?

Prenatal Diagnosis and Postnatal Outcomes of Persistent Left Superior Vena Cava Associated With Mild Narrow Aorta: A Cohort Study

PURPOSE

To explore prenatal ultrasonic features and prognosis of the persistent left superior vena cava (PLSVC) complicated with mild narrow aorta.

MATERIALS AND METHODS

A retrospective study was conducted involving 1348 fetuses diagnosed with PLSVC prenatally between January 2016 and December 2019. Forty-five fetuses with PLSVC associated with mild narrow aorta were selected from the cohort as the study group and 79 fetuses with isolated PLSCV were recruited randomly as the control group. All clinical and ultrasound results, including images and parameters of cardiac structures, were reviewed retrospectively. General conditions, ultrasound (US) measurements, and fetal prognosis were compared between the groups.

RESULTS

Aorta valve diameter (AOD), Z-score of aorta valve (AODz-score), aortic isthmus diameter (AOIsD), and pulmonary diameter (PAD)/AOD were significantly different in study group than control group no matter in the second or third trimester. Thirty-eight fetuses in study group were born with favorable outcomes after long-term follow-up. A total of 13.16% (5/38) remain mild narrow aorta and 3 of them showed smaller left ventricle after 3 years follow up. Prenatal AODz-score in infants remains mild narrow aorta after 2 years aged was higher than ones' aorta return to normal (P = .01), especially when AODz-score >1.725. Moreover, when prenatal ratio of AOIsD/left subclavian artery was <1.12, it was more likely that the aorta would remain mildly narrow at age 2.

CONCLUSION

Fetuses diagnosed with PLSVC with mild narrow aorta had favorable prognosis. AODz-score and AOIsD/left subclavian artery may be two predictors that reveal the risk of a mildly narrowed aorta remaining after birth.

Association of Prenatally Diagnosed Isolated Single Left Superior Vena Cava and Postnatal Development of Coarctation of the Aorta

To report the prevalence of coarctation of the aorta (CoA) in fetuses with single left superior vena cava (SL-SVC) and to evaluate changes in echocardiographic measurements. Additionally, to report the prevalence of associated malformations. Retrospective observational study of fetuses diagnosed with SL-SVC between 2012 and 2021 at a tertiary fetal cardiology unit. In fetuses without intracardiac abnormalities, Z-scores of the ventricles, great arteries, and Doppler flow patterns are reported. We identified 47 fetuses with SL-SVC of which 8/47 (17%) had abnormal intracardiac anatomy. One fetus was lost to follow-up. Of those with normal intracardiac anatomy and postnatal follow-up (38), karyotype abnormalities were confirmed in 2/38 (5%) and ECA in 8/38 (21%). 33/38 were live-born. None developed CoA postnatally. Paired analysis of Z-scores between early and late scans of 24 fetuses showed that diameters of the right heart structures and Doppler flows of tricuspid valve increased significantly during pregnancy, while the left heart structures and flow patterns did not change. The median risk of CoA did not change between the early and the late scan. We did not observe CoA in this cohort. A degree of ventricular asymmetry was present, but this was due to right heart dominance rather than hypoplasia of left heart structures. This likely reflects redistribution of blood and does not appear to confer increased risk of CoA. Predictive models of the postnatal development of CoA which set the dimensions of right and left heart structures in relation might not be applicable in this situation.

Persistant Left Superior Vena Cava with and Without Right Superior Vena Cava: Significance of Prenatal Diagnosis

This study aims to define the associated anomalies with PLSVC, and to compare single PLSVC and bilateral superior vena cava in terms of accompanying anomalies and pregnancy outcomes. This was a retrospective study of the fetuses diagnosed with single and/or bilateral SVC at a tertiary fetal medicine center during 8 years. We detected 16 cases of single PLSVC and 84 cases of bilateral SVC. We found an association between the PLSVC and cardiac and extracardiac anomalies. Comparison between single PLSVC and BSVC cases revealed significant differences in the occurrence of heterotaxy and right isomerism. The study highlights the importance of prenatal diagnosis in PLSVC cases. Isolated PLSVC with situs solitus may be considered a benign finding, but larger studies are needed to understand the clinical implications of PLSVC in relation to chromosomal anomalies. Routine screening protocols should include three-vessel and trachea views to detect PLSVC.

Integrated analysis of comorbidity, pregnant outcomes, and amniotic fluid cytogenetics of fetuses with persistent left superior vena cava

BACKGROUND

Persistent left superior vena cava (PLSVC) is the most common venous system variant. The clinical characteristics and amniotic fluid cytogenetics of fetuses with PLSVC remain to be further explored.

AIM

To develop reliable prenatal diagnostic recommendations through integrated analysis of the clinical characteristics of fetuses with PLSVC.

METHODS

Cases of PLSVC diagnosed using prenatal ultrasonography between September 2019 and November 2022 were retrospectively studied. The clinical characteristics of the pregnant women, ultrasonic imaging information, gestational age at diagnosis, pregnancy outcomes, and amniocentesis results were summarized and analyzed using categorical statistics and the chi-square test or Fisher's exact test.

RESULTS

Of the 97 cases diagnosed by prenatal ultrasound, 49 (50.5%) had isolated PLSVC and 48 (49.5%) had other structural abnormalities. The differences in pregnancy outcomes and amniocentesis conditions between the two groups were statistically significant (P < 0.05). No significant differences were identified between the two groups in terms of advanced maternal age and gestational age (P > 0.05). According to the results of the classification statistics, the most common intracardiac abnormality was a ventricular septal defect and the most common extracardiac abnormality was a single umbilical artery. In the subgroup analysis, the concurrent combination of intra- and extracardiac structural abnormalities was a risk factor for adverse pregnancy outcomes (odds ratio > 1, P < 0.05). Additionally, all abnormal cytogenetic findings on amniocentesis were observed in the comorbidity group. One case was diagnosed with 21-trisomy and six cases was diagnosed with chromosome segment duplication.

CONCLUSION

Examination for other structural abnormalities is strongly recommended when PLSVC is diagnosed. Poorer pregnancy outcomes and increased amniocentesis were observed in PLSVC cases with other structural abnormalities. Amniotic fluid cytogenetics of fetuses is recommended for PLSVC with other structural abnormalities.

Heterotaxy Syndrome with Increased Nuchal Translucency and Normal Karyotype Associated with Complex Systemic Venous Return. Ultrasound Diagnosis with Autopsy Correlation

Background: Prenatal ultrasound (US) detection of heterotaxy syndrome can be challenging, especially in identifying cardiovascular and associated anomalies. We present a new case of heterotaxy syndrome with anomalous systemic venous return (ASVR) fully displayed at autopsy. Case report: Left heterotaxy syndrome was diagnosed in a 19 weeks' of gestation fetus with right-sided stomach. The heart showed both ventricles with left morphology, a large ventricular septal defect, persistent left superior vena cava draining into the coronary sinus, ASVR with interrupted inferior vena cava (IVC) and azygous continuation. Autopsy dissection further identified the azygous draining into the left lower pulmonary vein (LLPV). Prenatal a-CGH on villous sampling showed 22q13.1 microduplication inherited from the father, not contributory to the phenotype. Conclusion/discussion: Heterotaxy syndrome requires US accuracy for anomaly identification, as they allow legal termination of pregnancy. Our case is unusual as IVC drained into the azygous vein and then into the LLPV.