Clinical presentation, conventional/4D spatio-temporal image correlation imaging findings, pregnancy and early postnatal outcomes in fetuses having anomalies of systemic venous return in the absence of significant intracardiac defects: A retrospective study from two centres in Southern India.

BACKGROUND
Recent advances in fetal ultrasound imaging, especially four-dimensional (4D) spatio-temporal image correlation techniques permit detailed evaluation of the fetal venous system and its abnormalities. In this report, we present the clinical presentation, conventional/4D spatio-temporal image correlation imaging findings, pregnancy, and early postnatal outcomes in fetuses having anomalies of systemic venous return in the absence of significant intracardiac defects from two centres in southern India.


OBJECTIVES
To report the clinical presentation, conventional/4D spatio-temporal image correlation imaging findings, pregnancy, and early postnatal outcomes in fetuses having anomalies of systemic venous return in the absence of significant intracardiac defects from two centres in Southern India.


METHODS
Retrospective study (October 2017 to March 2022). All fetuses referred with abnormal cardiac imaging findings who were diagnosed to have anomalies of systemic venous return in the absence of significant intracardiac defects were included. Imaging techniques like 2D with color and 4D spatio-temporal image correlation fetal imaging were used to evaluate systemic venous anomalies. Systemic venous anomalies were grouped into cardinal venous anomalies and umbilico-portosystemic venous anomalies.


RESULTS
Thirty-nine fetuses were included; this represented 4.4% of all cardiac anomalies diagnosed during the study period. Cardinal venous anomalies were seen in 29 fetuses (74%); the mean gestation age at diagnosis was 25.5 ± 3.4 weeks. Absent dilated coronary sinus was associated with anomalous drainage of superior caval vein through completely unroofed coronary sinus into the left atrium (n = 3) which resulted in cyanosis after birth in all infants. Among the three cases, one underwent surgery at 6 months of age due to a progressive increase in cyanosis (Spo2 78%) and others are awaiting surgery. A prenatal genetic evaluation was performed in 17 (58.6%). Cardinal venous anomalies were not associated with genetic abnormalities. Live births occurred in all fetuses with cardinal venous anomalies. Umbilico-portosystemic venous anomalies were seen in 10 (26%). The mean gestation age at diagnosis was 26.5 ± 4.5 weeks. Except in a fetus with the extrahepatic portosystemic shunt (umbilical vein to iliac vein), the genetic evaluation was normal in our cohort. Extracardiac anomalies (n = 3/10; 30%) were seen in both intra (n = 1) and extrahepatic portosystemic shunts (n = 2).


CONCLUSION
Anomalies of systemic venous return in the absence of significant intracardiac, extracardiac, and genetic abnormalities carried an overall favorable prognosis in our cohort. Precise characterization of anatomic details using advanced imaging techniques helps in the understanding of this complex three-dimensional anatomy and in the prognostication of these anomalies.