Prenatal diagnosis of abnormal cardinal systemic venous return without other heart defects: a case series.

Objectives: To describe fetal spectrum and echocardiographic characteristics of anomalous systemic venous return (ASVR, cardinal veins) without other structural heart defects (isolated ASVR), evaluate associated extracardiac and genetic anomalies and review neonatal outcome.

Methods: From 2003 to 2009, 369 consecutive fetuses were diagnosed with cardiac malformation, including 27 cases with an isolated ASVR. The following variables were collected: type of ASVR, extracardiac anomalies, karyotype and short-term outcome.

Results: The most common forms of ASVR were persistent left superior vena cava (SVC) (n = 15) and interrupted inferior vena cava (IVC) (n = 6). The other ASVR types were a persistent left SVC without a right SVC (n = 4), bilateral agenesis of the SVC with cephalic venous drainage toward the IVC through the azygos system (n = 1) and total ASVR to the coronary sinus (n = 1). Genetic disorders were confirmed in five cases, all with a persistent left SVC, with extracardiac anomalies present in four of them. Ten other patients had extracardiac anomalies detected prenatally or postnatally. When available, ASVR diagnosis was confirmed postnatally in all cases.

Conclusion: Isolated ASVRs can be accurately diagnosed prenatally and are frequently associated with extracardiac and genetic anomalies. A detailed morphological ultrasound and fetal karyotype should be suggested. Neonatal outcome was mainly related to the associated anomalies.