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