2010-08-03-09 Umbilical vein varix, Intra-abdominal © Cerekja www.TheFetus.net
Umbilical vein varix, Intra-abdominal
Albana Cerekja, MD, PhD*, Juan Piazze MD, PhD**.
* Ultrasound Division, ASL Roma B, Rome, Italy
** Ultrasound Division, Ceprano Hospital, Ceprano, Italy.
Aneurysm and varix are both focal dilatations of the umbilical vessels affecting the umbilical artery or vein respectively.
1) Intra-abdominal portion of the umbilical vein and / or umbilical portion of the left portal vein (i.e. intrahepatic or intra-abdominal extrahepatic). It involves more frequently the intraabdominal extrahepatic portion of the umbilical vein because this is part of the vessel with the least support.
Varix of the umbilical vein is an uncommon anomaly, representing only 4% of umbilical cord malformations (1). There are two following types of umbilical vein varices:
2) Intra-amniotic portion of the umbilical vein. This type has rarely been reported (2).
A varix of the intra-abdominal part of the umbilical vein is recognized as a cystic round or fusiform shaped mass oriented obliquely in the caudo-cranial direction and located within the liver (intrahepatic type) or between the abdominal wall and the inferior edge of the liver (extrahepatic type) (3).
Rarely, it may show as a large mass. Color Doppler and color flow imaging is valuable tool in the prenatal diagnosis. It demonstrates continuous or turbulent flow within the mass. Color flow imaging and its continuity with the umbilical vein, allows a definite diagnosis of the umbilical vein varix (4) and differentiation from other abdominal cystic masses.
Mahony et al. showed that the diameter of the normal intra-abdominal umbilical vein increases linearly with the gestational age. It ranges from 3 mm at 15 weeks gestation to 8 mm at term (R = 0.92) (3).
Diagnostic criteria of umbilical vein varix include:
- umbilical vein diameter greater than 9 mm
- or minimum 50% enlargement in the varix diameter than the diameter of the intrahepatic umbilical vein (5).
Choledochal, liver, mesenteric, ovarian or urachal cyst, cystic lymphangioma.
Regarding the clinical significance of the umbilical vein varix, literature reports controversial data: favorable outcome (2,6,7) and high incidence of fetal anomalies (8) and/or obstetric complications mostly due to thrombosis of the varix (3,9).
Although data are discordant, a meticulous study of the fetal morphology and serial sonographic evaluation of the fetus, with particular attention to the blood flow within the varix, should be carried out.
Case report 1
This is a case of a 33-year-old patient in her second pregnancy (G2 P1). Her previous pregnancy, 10 years ago, was uneventful and she delivered healthy baby, neonatal weight of 4500 grams. Patient and her husband, father of the baby, were both tall, she measured 178 cm and him 190 cm.
Her current pregnancy was uncomplicated and previous ultrasound examinations performed at different center were reported as normal.
At 33 weeks of gestation, her amniotic fluid index (AFI) was 30 cm and an estimated fetal weight was 3000 grams (abundantly above the 95° percentile) with proportional fetal growth. There was no sign of visceromegaly.
We saw an ovoid structure at the level of the urinary bladder. The structure showed continuity with the intraabdominal part of the umbilical vein that resulted to be of a normal diameter at the hepatic level. The largest diameter measured 13 mm. The Doppler showed continuous flow. Our diagnosis was intraabdominal extrahepatic umbilical vein varix.
Patient delivered spontaneously at 38 weeks. A healthy female of 4300 grams, neonatal length of 55 cm, Apgar scores of 9/10 at 1st/5th min respectively, was born. Both were dismissed in very good conditions 3 days after delivery.
Images 1,2: Images show an anechogenic lesion, umbilical vein varix, in front of the urinary bladder measuring 13 mm in diameter.
Images 3,4: Image 3 shows umbilical vein varix in front of the urinary bladder. Image 4 shows the varix in the longitudinal view.
Images 5 - 8: Color Doppler of the umbilical vein varix with continuous flow.
Images 9,10: Images showing the extrahepatic location of the varix.
Case report 2
This is a case of a 27-year-old patient G3 P2. She suffered from epilepsy and was under continuous treatment with antiepileptics, depakin (sodium valproate), tegretol (carbamazepin) and rivotril (clonazepam). Patient underwent a cardiac surgery for ventricular septal defect during her infancy. Her previous pregnancies were uncomplicated and she delivered her babies via cesarean section.
First and second trimester ultrasound scans were performed at a different center and were reported as normal. Fetal echocardiogram was normal.
The patient was scanned at our center 33 weeks of gestation. We performed an evaluation of the fetal growth and an estimated fetal weight, which was in 50-75° percentile. Amount of the amniotic fluid was increased (AFI=23 cm). Doppler measurement was normal.
There was a cystic structure at the level of the urinary bladder. It showed a color Doppler flow, continuous flow at pulsed Doppler and continuity with the intraabdominal segment of the umbilical vein. The largest diameter measured 14 mm. Our diagnosis was intraabdominal extrahepatic umbilical vein varix.
The cardiac examination showed a prominent flap of the foramen ovale, atrial septal aneurysm. It originated in the region of the fossa ovalis and extended into the left atrium, almost reaching the free atrial wall. The cardiac anatomy and rhytm were otherwise normal. We did not see any premature atrial contractions.
Patient delivered via cesarean section at 35 weeks. A healthy male neonate weighing 2750 grams with Apgar score 7/9 at 1st/5th minute was born. The baby was dismissed five days after delivery.
Images 1-4: Images show umbilical vein varix, round anechogenic lesion in the lower abdomen, in front of the urinary bladder, 14 mm in diameter.
Images 5,6: Color Doppler of the umbilical vein varix.
Images 7,8: Image 7 shows a continuous flow via umbilical vein varix. Image 8 shows a umbilical artery Doppler.
Image 9: Normal appearance of the umbilical vein at the level of the liver.
Images 10-13: Images show a 4-chamber-view of the heart. Note the flap of the foramen ovale almost reaching free left atrial wall, atrial septal aneurysm..
Videos 1,2: Videos showing the atrial septal aneurysm.
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2. White SP, Kofinas A. Prenatal diagnosis and management of umbilical vein varix of the intra- amniotic portion of the umbilical vein. J Ultrasound Med 1994;13(12):992-994.
3. Mahony BS, McGahan JP, Nyberg DA, Reisner DP. Varix of the fetal intra-abdominal umbilical vein: comparison with normal. J Ultrasound Med 1992;11(2):73-6.
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