Ductus venosus agenesis and portal system anomalies – association and outcome

Ductus venosus agenesis and portal system anomalies – association and outcome

REVIEWED BY | Ann Quinton ASA SIG: Women’s Health

REFERENCE | Authors: Nagy RD, Cernea N, Dijmarescu AL, Manolea M-M, Zorila G-L, Dragusin RC, et al. Journal: Biology 2022; 11:548

WHY THE STUDY WAS PERFORMED

There has been limited research assessing the association of fetal portal venous system (PVS) anomalies (both partial and total agenesis) and agenesis of the ductus venosus (DV).

HOW THE STUDY WAS PERFORMED

Prospective cohort study in a European tertiary prenatal unit of referred and routine second and third trimester scans. Sonographers were trained to identify i) DV in the longitudinal plane of the upper fetal abdomen; and ii) PVS in the transverse plane of the fetal abdomen at the level of the stomach and umbilical vein (UV). Junction of the portal sinus with the right and left portal veins and main portal vein were identified. All cases of agenesis DV were rescanned by maternal fetal specialists. Pregnant patients were offered karyotype and/or offered autopsy after termination or stillbirth. Live births had 6-month postnatal follow-up.

WHAT THE STUDY FOUND

Agenesis of DV is three times more common than PVS anomalies. Incidence of agenesis DV was 5.1%, and PVS anomalies was 1.9%. The best predictor of adverse outcomes for agenesis of DV was the presence of other fetal anomalies. Other anomalies included major cardiac anomalies and gastrointestinal atresias. There were in total 19/3517 cases of agenesis DV and/ or PVS anomalies: 12 cases with agenesis DV and normal PVS; three cases with agenesis DV and total PVS agenesis; three cases with agenesis DV and partial PVS agenesis; one case of DV present with partial PVS agenesis. When agenesis of the DV occurs, drainage can be i) via the PVS (intrahepatic), usually the left portal vein; or ii) connect to systemic veins outside of the liver (extrahepatic) including the femoral vein, inferior vena cava, azygous vein, coronary sinus or direct to atria. Fourteen cases of agenesis DV had intrahepatic drainage, three extrahepatic and one combined intra and extrahepatic drainage. Isolated agenesis DV occurred in 28% of these cases and 5/19 cases had abnormal karyotype (T21, 45X0, mosaicism). The authors felt PVS development is DV dependent, and as isolated agenesis of the DV had a good outcome, they questioned whether the poor outcomes reported in the previous work of agenesis DV are overestimated.

“This article describes new research which depicts how to scan the fetal portal venous system (PVS) and ductus venosus (DV) and assess for agenesis in both systems. It demonstrates how assessment of the PVS and DV can be incorporated into a routine scan.”

STRENGTHS AND LIMITATIONS OF THE STUDY

Prospective study on a mixed population of low and high risk pregnancies. Provided excellent labelled images of the PVS and DV and anomalous drainage and techniques for imaging. Outcomes being available in all cases was a strength, although postnatal outcomes were only up to 6 months, so long-term outcomes of partial PVS anomalies were not ascertained. Limitation: small numbers of cases of agenesis DV and PVS anomalies.

RELEVANCE TO CLINICAL PRACTICE

This work demonstrates how assessment of the DV and PVS can be incorporated into routine and tertiary practice. Isolated agenesis DV can have a good outcome. PVS anomalies were frequent in cases of agenesis DV with total PVS agenesis found in all cases of agenesis DV. When agenesis DV is found, the PVS should be interrogated. Total PVS anomalies and agenesis DV with other fetal anomalies are a predictor of poor fetal outcome.