Prenatal diagnosis of fetal pulmonary artery sling by two-dimensional ultrasound combined with STIC technology: a case report.

BACKGROUND: Pulmonary artery sling (PAS) is a rare congenital vascular anomaly, in which the left pulmonary artery arises aberrantly from the right pulmonary artery and courses between the trachea and esophagus, often causing tracheobronchial compression. It is frequently considered within the spectrum of vascular rings. Prenatal diagnosis remains challenging yet crucial for optimizing perinatal management and neonatal outcomes. This case report illustrates the enhanced diagnostic capability achieved by integrating conventional two-dimensional (2D) ultrasound with spatiotemporal image correlation (STIC) technology for the accurate prenatal identification of PAS.

CASE DESCRIPTION: A 33-year-old gravida 2 para 0 woman was referred for routine fetal assessment at 31 weeks of gestation. Initial 2D ultrasonography in the three-vessel tracheal view revealed an anomalous vascular configuration, suggesting the left pulmonary artery (LPA) originating from the right pulmonary artery (RPA). To confirm the diagnosis and delineate the vascular course, STIC technology was employed. The STIC volumetric acquisition and subsequent multi-planar reconstruction unequivocally demonstrated the LPA arising from the RPA and coursing posteriorly behind the trachea, thereby confirming the diagnosis of PAS. A comprehensive fetal echocardiogram excluded associated intracardiac anomalies. Following extensive parental counseling, the pregnancy continued uneventfully. The infant was delivered via elective cesarean section at 38+2 weeks and developed mild respiratory symptoms postnatally, requiring transient non-invasive support. Postnatal computed tomography angiography (CTA) confirmed the prenatal findings. Surgical correction was successfully performed at 3 months of age, with an excellent outcome at 6-month follow-up.

CONCLUSIONS: The synergistic use of routine 2D ultrasound and STIC technology provides a robust, clinically accessible method for the precise prenatal diagnosis of fetal PAS. This integrated imaging approach facilitates definitive diagnosis, enhances parental counseling, enables coordinated multidisciplinary perinatal planning, and ensures timely surgical intervention, all of which are pivotal for achieving favorable long-term outcomes in affected infants.