Retrocaval (Circumcaval) Ureter


 

General Considerations

  • Also known as “circumcaval ureter”
  • Abnormality in embryogenesis of IVC
    • Results from abnormal persistence of right subcardinal vein positioned ventral to ureter in the definitive IVC
    • Developing right ureter courses behind and medial to the IVC
  • Incidence
    • 0.07%
    • Male to female ratio of  3:1

Clinical Findings

  • Symptoms of right ureteral obstruction
    • Pain
    • Hematuria

Imaging Findings

  • Normal course of ureters
    • About the width of your thumb lateral to the lumbar vertebral pedicles
    • About the width of two fingers medial to pelvic brim in true pelvis
  • With retrocaval ureter
    • Right ureter’s course swings medially over pedicle of L3/4
      • Passes behind IVC
    • Then exits anteriorly between IVC and aorta returning to its normal position in lower third
    • Produces varying degrees of proximal hydroureteronephrosis
  • Can be associated with Turner’s syndrome
  • Types of retrocaval ureter

Types of Retrocaval Ureter

Type 1

More common. Ureter crosses behind IVC at level of  third lumbar vertebra; has fish hook  shape at point of obstruction.
Marked hydronephrosis in 50%

Type 2

Less common. Ureteral crossover higher at level of renal pelvis.
Mild hydronephrosis in majority of this type

 

Differential Diagnosis

 

Causes of Ureteral Deviation or Displacement

Medial Displacement or Deviation

Upper ureter

Lower ureter

Retrocaval ureter

Lymphadenopathy

Retroperitoneal fibrosis

Iliac artery aneurysm

 

Bladder diverticulum

 

Post-surgical (esp. AP resection)

 

Pelvic lipomatosis

Lateral Displacement or Deviation

Upper ureter

Lower ureter

Lymphadenopathy

Pelvic mass, e.g. uterine fibroids

Aortic aneurysm

 

Retroperitoneal hematoma

 

 

Treatment

  • Surgery may be done if there is hydronephrosis or recurrent infection

 



Retrocaval ureter. Coronal reformatted MIPS image from a CT urogram demonstrates medial
displacement of the right ureter at the level of L3 (White arrow). The ureter is medial to the pedicle
of the vertebral body (blue arrow). The Axial CT (below) shows the inferior ureter (white arrow)
coursing posterior to the inferior vena cava (red arrow).

For this same photo without the arrows, click here and here
For more information, click on the link if you see this icon

       

Herman, T and McAlister, W: Radiologic Clinics of North America. Vol. 29:2, March, 1991.

Retrocaval ureter. B. B. Hyams, C. Schneiderman, and A. B. Mayman. Can Med Assoc J. 1968 January 6; 98(1): 45–49