Retrocaval Ureter
  

• 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
• 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
    • Produces varying degrees of proximal hydroureteronephrosis

Retrograde pyelogram of right ureter demonstrates displacement of the ureter which passes
medial to the pedicle ft the level of L4. The ureter is slightly dilated proximal to this point and returns to a
normal position distal to its retrocaval placement.

CT scan below the level of the kidneys demonstrates a more medial
retrocaval placement of the right ureter.

• Retrocaval ureter can be associated with Turner’s syndrome
   

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

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