RETROCAVAL URETER PRESENTING AS HYDROURETERONEPHROSIS - A Case Report with Review of Literature
SV Mehta*, SH Somani*, AA Bokil*,JB Bhawani**, M Patil***, PJ Chibber****
*Senior Resident; **Lecturer; ***Asst. Honorary; ****Honorary Professor and Head, Department of Urology, Sir JJ Hospital, Mumbai 400 008.
Hydroureteronephrosis due to obstruction is a common urological entity. A congenital malformation presenting late ( at the age of 42 years ) makes this case report interesting. The classical fishhook/reverse ‘J’ sign on intravenous urography helps in diagnosis.
Retrocaval ureter is a congenital abnormality in which the ureter passes behind the inferior vena cava leading to varying degrees of ureteral compression. It was first described by Hochsteller in 1893.
Developmentally, the metanephros forms in the pelvis and rises through a ring of embryonic venous channels as it moves to a lumbar position. The major venous channels in the very young embryo are the posterior cardinal veins. The minor venous channels, the subcardinal veins are connected to the posterior cardinal veins by numerous prominent anastomotic vessels. Normally the posterior cardinal vein undergoes a complete regression caudal to the renal vein, allowing the ureter to assume a more normal position i.e. ventral to the inferior vena cava. The subcardinal vein remains as a tributary of the inferior vena cava. Persistence of the posterior cardinal vein as the major portion of the infrarenal inferior vena cava causes medial displacement and compression of the ureter after the lateral migration of the kidney. The ureter spirals from a dorsolateral position above, to a venteromedial position below around the developing inferior vena cava. Variants of the condition include duplication of the vena cava with the ureter lying beside, between or behind the vascular limbs.
Most patients present with right lumbar pain. They may have recurrent urinary tract infection or episodes of acute pyelonephritis. Occasionally calculi may form above the obstruction and symptoms may be attributed to these.
A 42 year old male presented with right flank pain of 10 years duration. The pain was fixed, dull-aching and non radiating. He had 2 episodes of fever with chills associated with pain. He had no other urological complaints. Examination revealed tenderness in the right lumbar area and the right renal angle. Urine examination revealed 10-12 pus cells and cultures grew E. Coli sensitive to gentamycin and amikacin. His haematological profile including serum creatinine was normal. Ultrasonography showed right hydroureteronephrosis with cortical thickness of 1 cm and normal echotexture. The opposite kidney and bladder were normal.
Intravenous urography showed prompt concentration and delayed excreation of contrast on the affected side along with hydroureteronephrosis. The ureter was found to make a typical reversed ‘J’ shaped deformity (Fig. 1) as it passed behind the inferior vena cava, between the third and fourth lumbar verterbrae. Delayed plates showed hold up of contrast at 24 hours. A retrocaval ureter was suspected and the patient was prepared for retrograde pyelography with right renal exploration.
Cystoscopy with retrograde pyelography showed a tortuous ureter in the form of an Italic ‘S’ (Fig. 2). The patient was
Fig 1 Fig 2 Preoperative IVU showing fish hook deformity. Cystoscopy with retrograde pyelography showed a tortuous ureter in the italic ‘S’ form.
downwards towards the umbilicus. The ureter was hooked up and the retrocaval segment demonstrated. The abnormal segment was dissected off the vena cava easily and an end to end ureteroureterostomy was performed over a double ‘J’ stent, after excising the abnormal segment.
Post operatively the patient had an uneventful recovery. His flank pain disappeared and an intravenous urography repeated after 6 weeks showed reduction in the hydronephrosis (Fig. 3).
2 types of retrocaval ureters have been described  and are to be distinguished from the entity in which only a loop or knuckle of ureter passes behind the vena cava and re-emerges laterally. 
Type 1 (low loop) is the most common and the dilated proximal ureter assumes a reverse ‘J’ shape, possibly a ureteral kink, an adynamic segment or pressure from the psoas muscle is contributing to the obstruction.  The nondilated distal ureter emerges medially, crosses the right iliac vessels anteriorly and enters the pelvis and bladder normally.
Fig 3 Post operative IVU after 6 weeks showing reduction in hydronephrosis.
Type 2 (high loop) is rarer and goes behind the cava at the level of or just above the ureteropelvic junction. The condition can be confused with ureteropelvic junction obstruction. It has been suggested that circumcaval ureter be used to describe the condition in which the ureter crosses behind the vena cava and re-emerges medially.
No therapy other than observation is indicated in patients without symptoms. Occasionally nephrectomy is needed in the presence of thinned out cortex and poor function or infection. Renal sparing procedure was performed in this case due to good function and severe symptoms with evidence of infection.
Harril (1940) emphasised that the position of the ureter and involved structures makes transection of the pelvis with transposition and re-anastomosis the most efficient surgical treatment.
The performance of the anastomosis as far distally on the dilated segment as possible has the advantage of preserving the blood supply of the ureter that comes from the renal artery. If there are adhesions between the venacava and the ureter, the compressed segment can be left in situ and the ureteral anastomosis done. Transection and reanastomosis of the vena cava can be done but is not recommended.
- Bateson EM, Atkinson D. Circumcaval ureter : A new classification. Clin Radiol 1969; 20 : 173.
- Talner LB. Specific causes of obstruction. Pollack HM ed. Clinical urography Philadelphia WB Saunders. 1990; 12 : 1629.
- Kumar S, Bhandari M. Selection of operative procedure for Circumcaval ureter (type 1). Br J Urol 1985; 57 : 399.
- Campbell’s Urology 7th ed. WB Saunder’s Comp. Philadelphia. 1998.