Circumcaval ureter

From Dog

Circumcaval ureter (retrocaval ureter) is a ureteral disease of dogs characterized by abnormal ureteral positioning.

In this disease, the ureter exits the kidney at the caudal end of the renal hilus and passes dorsal to the caudal vena cava resulting in ureteral stenosis and hydronephrosis at the ureteropelvic junction.

This condition is often an incidental finding at postmortem but has been diagnosed antemortem in dogs.

Circumcaval ureter is usually associated with concurrent congenital defects such as intrahepatic portosystemic shunts[1] or transposition of the caudal vena cava[2].

It may occur unilaterally (more common) or bilaterally[3].

A circumcaval ureter has been reported in the Bernese Mountain Dog which presented clinically with shifting hindlimb lameness and lethargy due to hypertrophic osteoarthropathy.

Diagnosis may be difficult but can be presumptively diagnosed pre-surgically with excretory urography, static fluid magnetic resonance urography and dynamic contrast-enhanced magnetic resonance urography.

A differential diagnosis would include other causes of hydronephrosis such as ureteroliths, nephroliths, pyelonephritis, urothelial carcinoma, ureteral stenosis, ureteral atresia, ureteral duplication[4], ectopic ureter[5] and ureteral unicornis[6].

Unilateral circumcaval ureters can be surgically corrected by transection and anastomosis of the ureter and repositioning it ventral to the vena cava, usually resulting in resolution of clinical signs.

References

  1. Doust RT et al (2006) Circumcaval ureter associated with an intrahepatic portosystemic shunt in a dog. J Am Vet Med Assoc 228(3):389-391
  2. Duconseille AC et al (2010) Imaging diagnosis - left retrocaval ureter and transposition of the caudal vena cava in a dog. Vet Radiol Ultrasound 51(1):52-56
  3. Honma S et al (2007) Preureteric inferior vena cava with possible rudiment of the proper inferior vena cava. Ann Anat 189(2):191-195
  4. Esterline ML et al (2005) Ureteral duplication in a dog. Vet Radiol Ultrasound 46(6):485-489
  5. North C et al (2010) Congenital ureteral ectopia in continent and incontinent-related Entlebucher mountain dogs: 13 cases (2006-2009). J Vet Intern Med 24(5):1055-1062
  6. Rousset N et al (2011) Unilateral hydronephrosis and hydroureter secondary to ureteric atresia, and uterus unicornis in a young terrier. J Small Anim Pract 52(8):441-444