Retrocaval ureter or preureteral vena cava: Lest we forget this rare cause of hydronephrosis

Abstract

Retrocaval ureter or circumcaval ureter is a rare congenital abnormality arising from dysgenesis of the inferior vena cava (IVC) that results in the right ureter coursing behind and medial to the IVC. The ideal nomenclature for the anomaly is preureteral vena cava, keeping in mind the aberrant embryology. It can result in hydronephrosis and is a rare cause of long-standing cyclical pain abdomen. Ultrasound, intravenous urography, nuclear scintigraphy, computed tomography urography (CTU) and magnetic resonance urography (MRU) have been used in the diagnosis of this abnormality but CTU, with its ability to depict the abnormality in three dimensions gives the most "wholesome" solution to its diagnosis. When symptomatic, the condition is treated surgically, either by laparoscopic or open surgery. The characteristic imaging findings that can help clinch the diagnosis are described as a reminder for this infrequently encountered cause for pain abdomen and hydronephrosis.

Percutaneous nephrolithotomy and retroperitoneal laparoscopy in treatment of retrocaval ureter with right renal and ureteral calculi: a case report

“…According to the relationship between the ureter and the vena cava, retrocaval ureter can be classified as type I, type II, and type III. 2 The periureteral space is narrower in patients with type II retrocaval ureter. The pressure of the ureter towards the vena cava readily causes clinical symptoms and secondary calculi; notably, type II retrocaval ureter is more commonly encountered in clinical practice, with the characteristic imaging finding of "fish-hook" morphology.…”

“…2 The principles of retrocaval ureteral treatment are as follows: (1) patients who exhibit mild hydronephrosis or calyceal hydronephrosis without hydronephrosis can be closely observed and regularly reexamined, without active treatment; (2) surgical treatment should be performed as soon as possible when severe hydronephrosis is present and the upper ureter exhibits obvious dilation that affects the function of the right kidney; (3) patients with recurrent infection, secondary stones, and bleeding require urgent surgical treatment. 2,5 Our patient exhibited retrocaval ureter and right ureteral calculi with right hydronephrosis and right renal calculi. Ureteral calculi occur above the site where the vena cava causes pressure to the ureter; their presence constitutes a surgical indication.…”

“…1 Treatment of retrocaval ureter depends on the degree of renal functional damage and the type of retrocaval ureter in an affected patient. 2 Asymptomatic patients without obstructions visible in imaging examinations can undergo regular follow-up without active treatment. When obstruction leads to renal failure and the contralateral kidney is normal, nephrectomy is feasible; when ureteral obstruction and corresponding symptoms occur, ureteroplasty (i.e., ureteral reduction and orthopedic surgery [anterior to inferior vena cava transposition, combined with ureter anastomosis]) is the main treatment approach.…”

“…When obstruction leads to renal failure and the contralateral kidney is normal, nephrectomy is feasible; when ureteral obstruction and corresponding symptoms occur, ureteroplasty (i.e., ureteral reduction and orthopedic surgery [anterior to inferior vena cava transposition, combined with ureter anastomosis]) is the main treatment approach. 2 Notably, laparoscopic surgery is the gold standard of treatment. 3 The incidence of retrocaval ureter is approximately 0.13%.…”

Obstructed left retrocaval ureter in a dog

“…The ventrally located CVC can cause compression and narrowing of the ureter leading to ureteral wall hypertrophy and sclerosis 5. Retrocaval ureters are largely an incidental finding in human beings and in affected patients, it is almost exclusively seen affecting the right ureter, with male patients over‐represented 4 6–8…”