PERSISTENT RIGHT UMBILICAL VEIN

 ±  ABNORMAL EXTRAHEPATIC CONNECTIONS

A right umbilical vein is a relatively common variation (23:10,000) where the right umbilical vein persists instead of obliterating around 6 weeks as a result from enlargement of the liver.

Persistent right umbilical vein may retain a number of primitive channels:

  1. Direct connection to the right atrium (1,2).
  2. Suprahepatic IVC.
  3. Infrahepatic IVC.
  4. Iliac veins.
  5. Subcutaneous collaterals to SVC.
  6. Direct connection to the portal venous system (2,3).

 

ULTRASOUND

 

  • Located lateral rather than medial to the gallbladder and curves towards the stomach. It passes to the right side of the gallbladder where it connects to the right portal vein.

  • Portal vein curves left towards the stomach rather than curving away to the right (1).

 

  • Color doppler facilitates the diagnosis by accentuating the aberrant intrahepatic course of the umbilical vein distinguishing it from the gallbladder (1).

 

ASSOCIATIONS

Link to Associations

 

 

PROGNOSIS

When a persistent right umbilical is identified a thorough search for other anomalies is essential. If no other anomaly is detected, the patient should be reassured that the condition is usually benign, and does not require further investigation.

Hill and co-workers: Found 33 cases in 15,237 consecutive cases. 6 cases (18.2%) had additional malformations (dysplastic kidneys, heart defects, hemivertebrae, caudal regression, clubbed feet, cleft lip and palate, IUGR, anencephaly, asplenia) (11).

Kinare and co-workers: Described in 10 fetuses, 6 of whom had associated anomalies (3 of the six had CNS defects) (12).

Ariyuki and co-workers: Describe two cases with no sequelae after birth (13).

Kirsch and associates: 9 cases of isolated right umbilical vein, no sequelae besides hypospadias were identified after birth (14).

Karyotyping may be indicated and should be dictated by the nature of the associated malformations that are present (1).

ANOMALIES  ASSOCIATED WITH A DIRECT COMMUNICATION

BETWEEN UMBILICAL VEINS AND SYSTEMIC CIRCULATION

1.      Noonan phenotype and nuchal edema (3,4).

2.      Single umbilical artery (5).

3.      Hydranencephaly (6).

4.      Endocardial cushion defect (7)

5.      Atrial septal defect (8).

6.      Total anomalous pulmonary venous drainage (9).

7.      Unilateral renal agenesis (2,9).

8.      Hydronephrosis (7).

9.      Unicornuate uterus (9).

10.  Hemivertebrae (2).

11.  Sympus dipus (10).

12.  Phocomelia (9).

13.  Bifid thumb (2).

 

REFERENCES
  1. Shen O, Tadmor P, Yagel S. Prenatal diagnosis of persistent right umbilical vein. Ultrasound Obstet Gynecol 1996;8:31-33.
  2. Greiss HB, McGahan JP. Umbilical vein entering the right atrium: significance of in utero diagnosis. J Ultrasound Med 1992;11:111-113.
  3. Currarino G, Stannard MW, Kolni H. Umbilical vein draining into the inferior vena cava via the internal iliac vein, by passing the liver. Pediatr Radiol 1991;21:265.
  4. Tordjeman N, Ville Y, Fermont L et.al. Anomalies of the umbilical vein in the fetus; A case report and review of the literature. J Gynecol Obstet Biol Reprod Paris 1996;25:495.
  5. Leonidas JC, Fellows RA. Congenital absence of the of the ductus venosus: With direct connection between the umbilical vein and distal inferior vena cava. AJR 1976;126:892.
  6. Fliegel CP, Nars PW. Aberrant umbilical vein. Pediatr Radiol 1984;14:55.
  7. 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 Obstet Gynecol 1996;7:21.
  8. Theander G, Karlsson S. Persistent right umbilical vein. Acta Radiol 1978;19:268.
  9. Bell AD, Gerlis LM, Varriend S. Persistent right umbilical vein – a case report and review of the literature. Int J Cardiol 1986;10:167.
  10. Shryock EH, Janzen J, Barnard MC. Report of a newborn human presenting sympus dipus, anomalous umbilical vein, transposition of the viscera and other anomalies. Anat Rec 1942;82:347.
  11. Hill LM, Mills MA, Peterson C et.al Persistent right umbilical vein: Sonographic detection and subsequent neonatal outcome. Obstet Gynecol 1994;84:923-925,
  12. Kinare AS, Ambardekar ST, Bhattacharaya D et.al. Prenatal diagnosis with ultrasound of anomalous course of the umbilical vein and its relationship to fetal outcome. J Clin Ultrasound 1996;24:333-338.
  13. Ariyuki Y, Hata T, Manabe A et.al. Antenatal diagnosis of persistent right umbilical vein. J Clin Ultrasound 1995;23:324-326.
  14. Kirsch CFE, Feldstein VA, Goldstein RB et.al. Persistent intrahepatic right umbilical vein: A prenatal sonographic series without significant anomalies. J Ultrasound Med 1996;15:371-374.