What are the implications of an absent ductus venosus (DV) after delivery?

Absent Ductus Venosus After Delivery: Clinical Implications

An absent ductus venosus (ADV) after delivery represents a rare congenital vascular anomaly that carries significant risk for associated cardiac and extracardiac malformations, chromosomal abnormalities, and persistent portosystemic shunts requiring postnatal intervention, though survival is possible depending on the specific pattern of abnormal venous circulation and associated anomalies.

Understanding the Anatomic Variants

The absent ductus venosus manifests in distinct patterns of abnormal venous circulation, each with different hemodynamic implications 1, 2:

• Extrahepatic shunts (worst prognosis): Umbilical vein bypasses the liver and connects directly to the right atrium (46% of cases) or to the inferior vena cava (25% of cases) 1, 3
• Intrahepatic connection: Umbilical vein connects to the portal circulation without forming a ductus venosus (21% of cases) 1
• Iliac/renal vein drainage: Umbilical vein drains into iliac or renal veins 2

The extrahepatic patterns, particularly direct connection to the right atrium, carry the highest risk of heart failure and adverse outcomes 1, 3.

Associated Anomalies and Chromosomal Risks

Major anomalies occur in approximately 24-58% of cases with ADV 1, 2:

• Chromosomal aberrations: Turner syndrome and Noonan syndrome are specifically associated 2
• Cardiac anomalies: Cardiomegaly is common and should prompt investigation 3, 4
• Extracardiac malformations: Facial clefts, hemivertebrae, genitourinary and gastrointestinal anomalies 3
• Portal vein absence: Found in 50% of examined infants after birth 1

Immediate Postnatal Assessment Required

Neonates with prenatally diagnosed ADV require comprehensive cardiovascular evaluation immediately after delivery to identify persistent portosystemic shunts and cardiac complications 4:

• Detailed echocardiography to assess cardiac function and identify abnormal venous connections 4
• Evaluation for hydrops, which develops in 33% of cases 1
• Assessment for portal vein presence, as absence occurs in half of affected infants 1
• Monitoring for signs of heart failure, particularly with extrahepatic shunting patterns 1, 3

Prognosis and Outcomes

The overall mortality rate is approximately 20% for isolated ADV cases, though outcomes vary significantly by anatomic pattern 1:

• Survival is possible: Four of six neonates survived in one series, with both deaths occurring in extrahepatic ADV cases 5
• Heart failure risk: Particularly elevated when umbilical vein connects to inferior vena cava or right atrium 1
• Intervention requirements: Some neonates require cardiovascular intervention, including device occlusion of persistent portosystemic shunts 4

Critical Management Considerations

The key determinant of prognosis is the specific pattern of abnormal venous circulation combined with the presence or absence of associated malformations 1, 3:

• Isolated ADV with intrahepatic portal connection has better prognosis than extrahepatic shunts 1, 3
• Normal karyotype improves outcomes significantly 5
• Absence of hydrops at birth is a favorable prognostic indicator 1

Postnatal Surveillance Strategy

Neonates with ADV require ongoing monitoring even if initially stable 4:

• Serial echocardiography to detect evolving cardiac dysfunction
• Assessment for development of hepatic complications related to abnormal portal circulation 1
• Evaluation for persistent portosystemic shunts that may require device occlusion 4
• Monitoring for manifestations of associated congenital anomalies 3

Common Pitfalls to Avoid

• Do not assume normal outcome based on prenatal stability: Postnatal decompensation can occur, particularly with extrahepatic shunting 1, 3
• Do not overlook portal vein assessment: Absence of the portal vein occurs in 50% of cases and has significant implications 1
• Do not delay cardiovascular intervention: Persistent portosystemic shunts may require device occlusion to prevent complications 4
• Do not miss associated anomalies: Comprehensive evaluation for cardiac, chromosomal, and extracardiac malformations is essential 3, 2