UMBILICAL VEIN VARIX

• Uncommon, representing only 4% of malformations of the umbilical cord (1).
• There are two types which may / may not be associated with malformations:
1. Intra-abdominal portion of the umbilical vein and / or umbilical portion of the left portal vein

(i.e. intrahepatic or intra-abdominal extrahepatic)

2. Intra-amniotic portion of the umbilical vein.

ULTRASOUND OF INTRA-ABDOMINAL VARIX (2)

• Cystic round or fusiform shaped mass.
• Orientated in an anteroposterior, caudocranial direction.
• Located within the substance of the liver (Intrahepatic type).
• Located directly cephalad to the insertion of the umbilical vein into the fetal abdomen.
• Differential diagnosis:
• Choledochal cyst.
• Liver, mesenteric, ovarian or urachal cyst.
• Cystic lymphangioma.

The demonstration of blood flow within the mass on color doppler differentiates the varix from the above cystic masses.

Intra-abdomonal intrahepatic varix
Intra-abdominal Extrahepatic varix

ULTRASOUND OF INTRA-AMNIOTIC VARIX

• Tortuous cystic varix of umbilical vein.
• Detection is enhanced by using color doppler imaging.
• Complications:
• Cord thrombosis (may be seen in 1 in 25 autopsies in fetuses with cord abnormalities) (3).
• Hemorrhage through the amniotic sheath with fetal demise.

PROGNOSIS

• Estroff and Bernacerraf (2) - excellent outcome for all five fetuses.
• Mahony and co-workers (4) - nine cases of fetal intraabdominal varix in which four fetuses died and one developed hydrops.
• White and Kofinas (5) - Normal outcome.
• Rahemtullah et.al. (7) – No fetal or neonatal deaths, but a high rate of fetal malformations (chromosomal, syndromes, cardiac defects and diaphragmatic hernia). 34.8% had major congenital abnormalities.

Cardiac decompensation, especially prior to 30 weeks gestation, has a worse prognosis.

REFERENCES

1. Jeanty P. Fetal funicular vascular anomalies: identification with prenatal ultrasound. Radiology 1989;173:367.
2. Estroff JA, Bernacerraf BR. Fetal umbilical vein varix: Sonographic appearance and postnatal outcome. J Ultrasound Med 1992;11:69-73.
3. Heifetz S. Thrombosis of the umbilical cord: Analysis of 52 cases and review of the literature. Pediatr Pathol 1988;8:37.
4. Mahony BS, McGahan JP, Nyberg DA et.al. Varix of the intra-abdominal umbilical vein: Comparison with normal. J Ultrasound Med 1992;11:73.
5. White SP, Kofins A. Prenatal diagnosis and management of umbilical vein varix of the intra- amniotic portion of the umbilical vein. J Ultrasound Med 1994;13:992-994.
6. Moore L, Toi A, Chitayat D. Abnormalities of the intra-abdominal fetal umbilical vein: report of four cases and a review of the literature. Ultrasound Obst Gynecol 1996;21-25.
7. Rahemtullah A, Lieberman E, Benson C. Outcome of pregnancy after prenatal diagnosis of umbilical vein varix. J Ultrasound Med 2001;20:135-139.