Utility of the 3-Vessel and 3-Vessel and Trachea Views in Prenatal Diagnosis of a Pulmonary Artery Sling

Fetal diagnosis and management of pulmonary artery sling: A case series

OBJECTIVE

Pulmonary artery sling is a rare congenital anomaly accounting for 2% of all patients with vascular anomalies that cause airway obstruction. In the normal heart, the left (LPA) and right (RPA) pulmonary arteries arise in the intrapericardial space. However, in the pulmonary artery sling, the LPA trunk arises in the extrapericardial space from the posterior aspect of the mid RPA and courses posterior to the trachea causing tracheal compression and, at times, bronchial compression. While a full spectrum of congenital cardiac pathology can be identified before birth, only a few case reports document the prenatal diagnosis of an Left pulmonary artery sling (LPAS).

METHOD

We retrospectively identified all cases of prenatal LPAS from three Canadian fetal cardiology centers (2015-2022).

RESULTS

Using the 3-vessel-tracheal view via fetal echocardiography (FE), four fetuses from three pregnancies demonstrated abnormal origin of the LPA from RPA and echogenic trachea. In one of two affected monochorionic twins coronal imaging demonstrated a significant narrowing of the large airways consistent with significant airway obstruction.

CONCLUSION

Prenatal detection of LPAS by FE is possible and should prompt an evaluation for airway obstruction in the coronal view. Investigating associated lesions and genetic testing are recommended for informed shared decision making.

Pregnancy outcomes of fetuses with congenital heart disease after a prenatal diagnosis with chromosome microarray

OBJECTIVE

To evaluate the pregnancy outcomes of fetuses with congenital heart disease (CHD) after chromosome microarray (CMA)-based prenatal diagnosis.

METHOD

Amniocentesis was performed in 1035 pregnant women carrying fetuses with CHD between September 2014 and December 2019. Chromosomal aberrations in fetuses with CHD were evaluated using CMA. The pregnancy outcomes were followed up from 6 months to 5 years.

RESULTS

The overall CHD detection rate by CMA was 10.1% (105/1035; 50 fetuses: aneuploidy, 55 fetuses: pathogenic or likely pathogenic copy number variations). Among 1003 fetuses who were followed up, 4, 236, 763, and 18 cases were of miscarriages, pregnancy termination, live births, and postnatal deaths, respectively. Self-healed CHD was observed in 401 (52.6%) fetuses. The pregnancy termination rate of fetuses with chromosomal anomalies was significantly higher than that of fetuses without chromosomal anomalies (93.1% vs. 15.5%, p < 0.001). However, other pregnancy outcomes, including mortality, preterm labor, and low-weight birth rate, were similar between the two groups.

CONCLUSION

The outcome of CMA is an important factor influencing parents' choice of whether to continue the pregnancy. Self-healing rate of prenatal diagnosed CHD is high. The mortality and morbidity of fetuses with CHD following prenatal CMA testing are relatively low.

Fetal Vascular Rings and Pulmonary Slings: Strategies for Two- and Three-Dimensional Echocardiographic Diagnosis

Fetal aortic arch anomalies and pulmonary slings can be difficult to accurately diagnose but have important clinical implications related to vascular rings, congenital heart disease, and chromosomal anomalies. In this article, the authors briefly review the embryology and development of the fetal arch to facilitate understanding of its diverse variants. Two-dimensional echocardiographic characteristics are summarized for each type of these malformations to propose a strategy for fetal diagnosis. The added benefits of three-dimensional echocardiography with spatiotemporal image correlation are also shown. Finally, the authors propose a strategy for volume acquisition and postanalysis to spur postanalysis clinical use of this technology.

Prenatal ultrasound diagnosis of fetal isolated right ventricular noncompaction with pulmonary artery sling: A rare case report

Noncompaction of the ventricular myocardium (NVM), also known as spongy myocardium, is a rare type of cardiomyopathy that has a serious impact on fetuses, children, and adults. NVM mainly affects the left ventricle, as isolated right ventricular noncompaction (IRVNC) is rare. Pulmonary artery sling (PAS) is a rare condition in which the left pulmonary artery anomalously originates from a normal positioned right pulmonary artery, and only a few studies have reported PAS in fetuses. Fetal IRVNC complicated with PAS has not been reported yet. Here, we report a case of IRVNC complicated with PAS that was diagnosed prenatally at 30 weeks gestation and confirmed by postpartum anatomy and pathology.

Prenatal diagnosis of left pulmonary artery sling and review of literature

Left pulmonary artery sling (LPAS) is a very rare cause of large airway compression. In LPAS, the left pulmonary artery (LPA) arises from the proximal right pulmonary artery, coursing over the right mainstem bronchus, posterior to the trachea and anterior to the esophagus prior to reaching the left hilum. The aberrant course of the LPA results in anatomical obstruction of the right mainstem bronchus, the trachea, or both. Only a few reports present the prenatal features of LPAS. In this report, we present the prenatal diagnosis of a case of LPAS in one of a set of identical twins in which the only feature was that of an abnormal course of the LPA on 3-vessel tracheal view. The cross-sectional view at the level of three vessels which includes both pulmonary artery branches is useful to detect this abnormality. Color and power Doppler may be helpful as well.