A case of retro-caval ureter and discussion

1. RETROCAVAL URETER

2. Case Report.
• 64 year old lady presented with complaints of right lower limb
edema x 6 months.
• H/o recurrent episodes of intermittent right flank pain.
• No relevant past medical and surgical history.

3. USG Abdomen ….
• Moderate right proximal hydro-ureteronephrosis
• No evidence of calculus.
• Normal left kidney and ureter.

4. EU….
hydronephrosis of the
right kidney and dilated
ureter upto the level of
the L3 vertebra with a
reverse-J deformity at
this level with non-
visualization of the distal
ureter
 Normal left kidney
and ureter.

5. CT Urogram..
• Right kidney: reveal normal size, shape, position and attenuation .Few small sub centimetric
simple cortical cysts are noted. There is proximal hydroureteronephrosis of the right kidney
upto the L3 vertebral level where ureter crosses lateral border of the right psoas muscle. It is
then noted making a cephalad course and deviating medially behind the inferior vena cava,
winding about and crossing in front of it to resume a normal course, distally, to the bladder.No
radiopaque stone is seen in the renal parenchyma or collecting systems. Features are suggestive
of Type I retro-caval ureter.
• Left kidneys: reveal normal size, shape, position and attenuation. Few small sub centimetric
simple cortical cysts are noted. No radiopaque stone is seen in the renal parenchyma or
collecting systems. No signs of obstructive uropathy are detected.
• Urinary bladder is normal. No focal mass or calculi.
• Other findings:
 Hepatomegaly.
 Mild nodularity involving the medial limb and body of left adrenal. Suggested further
evaluation if indicated.
 Few colonic diverticuli. No evident features of diverticulitis.
 Bilateral simple renal cortical cysts.
 Other findings as described above.

6. Current status…
• Patient symptomatically treated.
• Not operated.

8. Introduction..
• Retro-caval ureter /circum-caval ureter / pre-ureteral vena cava,
is a rare congenital anomaly in which the ureter passes posterior to the
inferior vena cava (IVC).
• The proximal ureter deviates medially passing behind the IVC and winding
around it before crossing anteriorly and laterally to resume its normal
course distally.
• It occurs in 1 in 1500 live births /overall incidence -0.006%–0.17%.
• M>F with a male-to-female ratio between 3 and 4:1.
• In clinical practice, reported cases have also shown male preponderance.

9. History and embryology…
• The first case was described by Hochstetter in 1893.
• The etiology relates to the embryological development of the ureter
and vena cava.
• The meta-nephros or fetal kidney, during its craniad migration
ascends through a ring of venous channels comprising of the
posterior cardinal and supracardinal veins dorsally and the
subcardinal vein ventrally.
• Normally the inferior vena cava forms from the right supracardinal
vein.
• However, if the ventrally placed subcardinal vein fails to regress and
becomes the vena cava instead, the ureter is trapped dorsal to it

13. • In a circumcaval ureter there is anomalous development of the infrarenal
IVC from the right posterior cardinal vein that is embryologically more
medial.
IVC
RIGHT SUBCARDINAL PRE-RENAL IVC
S.CARDINAL & SUPRA-
CARDINAL
ANASTOMOSIS
RENAL SEGMENT
RIGHT SUPRACARDINAL POST RENAL IVC
SUMMARY

15. Presentation
• Retrocaval ureter may be asymptomatic; discovered only during imaging or
surgery for unrelated pathology or at autopsy.
• It becomes symptomatic usually in the third or fourth decade of life due to
hydronephrosis from kinking of the ureter, compression or aperistaltic
segment (retrocaval segment).
• It usually occurs on the right side but can be on the left side in patients with
the very rare situs inversus, duplication of IVC or persistent left subcardinal
vein.
• Most patients present with right flank pain, recurrent urinary tract infection
(UTI), renal stones and hydronephrosis. It is also one of the causes of
pelviureteric junction (PUJ) obstruction.

16. • Some of the associated anomalies include
 -duplication of IVC,
 - situs inversus,
 -imperforate anus,
 -oesophageal atresia,
 -myelomeningocele,
 -renal agenesis,
 -horse shoe kidney,
 -ureteral duplication,
 -congenital absence of vas deference,
 - hypospadias,
 -syndactyly,
 -intestinal malrotation,
 -VECTERL and Turner's branchial arch or Goldenhar syndromes.

17. CLASSIFICATION…
• Bateson and Atkinson classified retrocaval ureter radiologically into two types in 1969.
▫ Type I/Low loop - typical S-shaped, 'fish hook' or 'Shepherd crook' deformity
extreme medial deviation in 50% of the cases at the level of L3
moderate-to-severe hydronephrosis.
most of the symptomatic cases.
▫ Type II/High loop -more gentle curve appearing as J-shaped or 'sickle'-shaped
deformity
medial deviation at the level of renal pelvis;
mild or no hydronephrosis in 10% of the cases
asymptomatic.

19. • Another classification scheme uses the level of obstruction in which
Type I -at the level of third lumbar vertebra
Type II - crosses at the level of ureteropelvic junction.

22. RADIOLOGICAL FINDINGS….
• Pyelography.
• EU.
• USG.
• CT
• MRI
• Renal functional imaging.
Any chosen imaging
modality will usually show
a right hydronephrosis
above the segment
embracing the IVC.

23. • The diagnosis of retrocaval
ureter can be confirmed
preoperatively with
antegrade or retrograde
pyelography.

24. • IVU/EU readily
demonstrates
hydroureteronephrosis
with upward curving and
abrupt termination of the
ureter and non-
visualisation of the
middle and distal thirds
of the ureter as seen in
Type I

25. • Abdominal ultrasound can at best demonstrate the presence of
hydronephrosis since it poorly delineates the ureter.

26. Spiral computerised tomography (CT) is considered the investigation
of choice compared to IVU because it can delineate both the ureter
and IVC.

29. • MRI may be better than the CT as it can delineate the course of the
entire ureter and is not associated with exposure to radiation as
compared to IVU or CT.
• Diuretic renography with diethylenetriaminepentaacetic acid or
mercaptoacetyltriglycine can assess the level of obstruction and
determine the best therapeutic modality.

30. Management…
• Asymptomatic patients and those with mild hydronephrosis and infection can
be managed non-operatively and followed up.
• surgical treatment is required in symptomatic patients or those with severe
hydronephrosis.
• Treatment can be by open or laparoscopic approach.
• The first successful surgical correction was by Kimbrough in 1935.
• It involved division of the ureter with or without excision of the narrowed or
aperistaltic segment, anteriorisation, uretero-ureterostomy or dismembered
pyeloplasty over a stent.
• Laparoscopic approach through transperitoneal or retroperitoneal route is less
invasive and associated with less morbidity, less post-operative pain, early
recovery, short hospital stay and cosmetically acceptable scar.
• Patients who are treated generally have an uneventful course and an excellent
prognosis.Post opeartive EU should be acquired.

31. References..
• Congenital anomalies of the inferior vena cava. Review of embryogenesis and presentation of a
simplified classification By Vincent P. Chuang, M.D.,* C. Ernesto Mena, M.D., and Phillip A.
Hoskins, M.D. Departments of Radiology, University of Michigan Medical Center and St. Joseph
Mercy Hospital, Ann Arbor, Michigan 48104 {Received March, 1973)
• The ‘‘fish hook’’ sign of retrocaval ureter Cane F. Hoffman, Raymond B. Dyer Department of
Radiology, Wake Forest Baptist Medical Center, Wake Forest University School of Medicine,
Medical Center Blvd., Winston-Salem, NC 27157, USA.