Indian Journal of Radiology and Imaging Indian Journal of Radiology and Imaging

GENITO-URINARY
Year
: 2000  |  Volume : 10  |  Issue : 3  |  Page : 157--158

Duplication of IVC and associated renal anomalies


NBS Mani, NK Venkataramu, Paramjeet Singh, Sudha Suri 
 Dept of Radiodiagnosis & Imaging, PGIMER, Chandigarh - 160 012, India

Correspondence Address:
Paramjeet Singh
Dept of Radiodiagnosis & Imaging, PGIMER, Chandigarh - 160 012
India




How to cite this article:
Mani N, Venkataramu N K, Singh P, Suri S. Duplication of IVC and associated renal anomalies.Indian J Radiol Imaging 2000;10:157-158


How to cite this URL:
Mani N, Venkataramu N K, Singh P, Suri S. Duplication of IVC and associated renal anomalies. Indian J Radiol Imaging [serial online] 2000 [cited 2020 Sep 21 ];10:157-158
Available from: http://www.ijri.org/text.asp?2000/10/3/157/30586


Full Text

Anomalies of the IVC are uncommon but are important clinical entities to vascular surgeons, radiologists, urologists and oncologists [1],[2],[3]. Duplication of IVC is a rare condition. It is known to be associated with various urogenital tract anomalies such as horseshoe kidneys and circum-aortic renal collar [4],[5],[6]. The radiologist must be well aware of this condition and should be able to differentiate between an anomalous IVC and pathological lymphadenopathy. In this report, we present imaging findings of duplication of IVC with rare association of renal developmental anomalies.

 Case Report



Case 1:

A fourteen-years-old boy who had right-sided congenital ureteropelvic junction obstruction with hydronephrosis underwent Anderson Hyne's pyeloplasty at the age of one. We evaluated him for abdominal pain suspecting ureteric colic. Plain radiographs, however, did not reveal calculi. He was subjected to abdominal CT scanning, both pre and post contrast. Scanning revealed a small right kidney, which was hydronephrotic with a grossly dilated pelvis [Figure 1]. There was delayed excretion of contrast into the pelvis. The left kidney and both ureters were normal. There was no calculus in either the kidney or the ureters. A tubular structure was seen to the left of the aorta [Figure 1] whose enhancement was similar to that of adjacent vessels, continuing inferiorly as the left common iliac vein and communicating superiorly with the left renal vein. Duplication of vena cava was diagnosed based on CT findings. Magnetic resonance venography revealed similar findings confirming the double vena cava in this patient [Figure 2].

Case 2:

A ten-years-old boy, who was diagnosed to have polycystic disease of the kidney (autosomal recessive type) at the age of two, underwent CT scanning for re-evaluation. The scan revealed enlarged kidneys with multiple small cysts and a striated nephrogram [Figure 3]. The liver also showed multiple cysts and ectatic biliary radicles. A tubular structure was seen as in the first patient, to the left of aorta with enhancement similar to that of adjacent vessels [Figure 3]. This structure was identified on contiguous slices. A diagnosis of double IVC was made based on these CT findings. MR venography was attempted. However the patient was claustrophobic and it had to be abandoned. Doppler ultrasound also revealed vascular signals consistent with venous flow confirming the diagnosis.

 Discussion



Duplication of IVC is an uncommon anomaly with an incidence of 0.2-3% [3]. Its origin can be understood from its development in the fetus. The development of normal IVC is a complex and continuously evolving process occurring during the sixth to tenth weeks of gestation [7]. The posterior cardinal veins appear first but regress completely except for the distal part, which forms the iliac bifurcation. The subcardinal veins appear next and are located medial and ventral to the posterior cardinal veins. The left subcardinal system regresses and the right subcardinal system forms the suprarenal segment of IVC. The supracardinal veins are the last to appear and are located medial and dorsal to the subcardinals. The left system regresses and the right persists to form the infrarenal segment of IVC. The development of the adult single right sided IVC therefore involves processes of vessel fusion, regression and formation of midline anastomoses between these three pairs of embryonic vessels [7].

Duplication of IVC or double IVC results from persistence of the left supracardinal vein. The size of both the vessels is variable and attempts have been made to classify such duplications as being of equal size or, left or right side dominant [8]. The size of the vessels was almost equal in our patients. The left sided vena cava typically starts as a continuation of the left common iliac vein and crosses anterior to the aorta to join the right at the level of the renal veins, as was demonstrated in our patients. However, venous communications have also been described at or near the common iliac level.

Duplication of the IVC can be associated with various genitourinary anomalies [4],[5],[6]. These include anomalies of the renal vein such as circum-aortic renal vein known as 'venous collar', retro-aortic left renal vein, cloacal exstrophy and horseshoe kidney. The exact cause and effect or association between IVC anomalies and genitourinary anomalies is not completely understood. Smith et al [6] postulated that due to fusion of metanephric buds in horseshoe kidneys and impairment of the normal renal ascent and rotation, the usual venous development could be disturbed [6]. The developing kidneys are cradled laterally by the large posterior cardinals and anteromedially by the distal subcardinals. With normal renal enlargement and migration, the posterior cardinals get compressed against the lateral pelvic wall and this probably leads to regression of posterior cardinals accompanied by enlargement of the anastomosing subcardinal and supracardinal systems.

In our cases, double IVC was associated with polycystic kidneys and congenital pelviureteric obstruction. An extensive search of English literature however, did not reveal any such associations. Although no definite reasoning could be attributed to such an association of double IVC and autosomal recessive polycystic kidney disease, a postulation can be made regarding the association of pelviureteric junction obstruction with double IVC. Both the subcardinal and supracardinal system form extensive anastomotic channels at the level of the renal vein which later coalesce to form a large vein anterior and posterior to the aorta, that drains the left kidney. Eventually the venous channel posterior to the aorta regresses and the vein anterior to the aorta persists to become the left renal vein. We believe that persistence of one of these midline anastomoses could have resulted in pelviureteric junction obstruction seen in one of our patients as the ureter lies dorsal to the posterior cardinal veins and ventral to the supracardinal veins. Contrast enhanced CT and/or MRI are usually sufficient to identify the anomalous vessel, differentiate it from lymphadenopathy and detect any associated renal anomalies.

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