Circumcaval Ureter

A circumcaval ureter in one that develops normally, but, due to the anomalous development of the inferior vena cava, ends up travelling posterior to the inferior vena cava and then travels around the medial border anteriorly to partially encircle the inferior vena cava. Patients may be asymptomatic or present with symptoms of ureteral obstruction.

The normal infrarenal inferior vena cava derives from the supracardinal vein, which is posterior to the ureter. A circumcaval inferior vena cava derives from the subcardinal or postcardinal veins, which are anterior to the ureter.

This should be differentiated from the normal oblique impression from the crossing iliac vessels, which occurs at the level of L5 or S1. Adenopathy, retroperitoneal fibrosis, or pelvic lipomatosis may also be considered in the differential.

A circumcaval ureter can be associated with horseshoe kidney, Turner syndrome, and double vena cava.

References

Lautin EM, Haramati N, Frager D, Friedman AC, Gold K, Kurtz A, Self J. CT diagnosis of circumcaval ureter. AJR Am J Roentgenol. 1988 Mar;150(3):591-4.