congenital anomalies of ivc

CONGENITAL ANOMALIES OF IVC

By Dr M.Ajay. K & Dr Eranna Palled

Please visit www.jssmcradiology.com for more cases


There are Spectrum of Congenital Anomalies of the Inferior Vena Cava and are usually seen in asymptomatic patients .

TYPESI. Left IVCII. Double IVCIII. Azygos continuation of the IVCIV. Circumaortic left renal veinV. Retroaortic left renal veinVI. Circumcaval ureterVII. Double IVC with Retroaortic Right Renal Vein and

Hemiazygos Continuation of the IVCVIII. Double IVC with Retroaortic Left Renal Vein and Azygos

Continuation of the IVCIX. Absent Infrarenal IVC with Preservation of the Suprarenal Segment


I. Left IVC

It is seen as a result from regression of the rightsupracardinal vein with persistence of the leftsupracardinal vein.

Prevalence is 0.2%–0.5%.

Here left IVC joins the left renal vein, which crosses anterior to the aorta in the normal fashion, uniting with the right renal vein to form a normal right-sided prerenal IVC


Schematic shows a left IVC terminating at the left renal vein.


LEFT SIDED IVC IN A PATIENT OF 28 YEARS OLD WITH PANCREATITIS COMPLICATED WITH PSEUDOCYSTS

Left IVC inferior to the renal veins. Left IVC joins the left renal vein



Left IVC crossing over aorta before uniting with right renal vein

Left IVC shifted towards right side and in close relation with small pseudocyst



Left IVC shifted towards right side compressed by large pseudocyst



Hepatic veins draining into IVC


II Double IVC : the left IVC typically ends at the left renal vein, which crosses anterior to the aorta to join the right IVC

III Azygos continuation of the IVC : the prerenal IVC passes posterior to the diaphragmatic crura to enter the thorax as the azygos vein

IV Circumaortic left renal vein : one left renal vein crosses anterior to the aorta and another crosses posterior to the aorta.

V Retroaortic left renal vein : As with circumaortic left renal vein, a retroaortic left renal vein results from persistence of the dorsal arch of the renal collar


VI Circumcaval ureter

VII Double IVC with Retroaortic Right Renal Vein and Hemiazygos Continuation of the IVC.

VIII Double IVC with Retroaortic Left Renal Vein and Azygos Continuation of the IVC

IX Absent Infrarenal IVC with Preservation of the Suprarenal Segment


EMBRYOGENESIS OF THE IVC

The infrahepatic IVC develops between the 6th and 8th weeks of embryonic life as a composite structure formed from the continuous appearance and regression of three paired embryonic veins.

In order of appearance, they are the posterior cardinal, the subcardinal, and the supracardinal veins .

Initially, all blood return from the body wall caudal to the heart proceeds through the posterior cardinal veins


EMBRYOGENESIS OF THE IVC Blood return from the viscera is conveyed by the vitelline

veins , which drain the yolk sac.

Subsequently, the subcardinal veins develop ventromedial to the posterior cardinal veins and ventrolateral to the aorta.

The intersubcardinal anastomosis forms between the paired subcardinal veins anterior to the aorta and caudal to the superior mesenteric artery.

Anastomoses between the posterior cardinal and subcardinal veins develop on each side at approximately the level of the intersubcardinal anastomosis.


EMBRYOGENESIS OF THE IVC At the same time, union occurs between the right

subcardinal vein and the hepatic segment of the IVC, which forms from the vitelline vein.

As the cranial portions of the posterior cardinal veins begin to atrophy,blood return from the lower extremities is shunted through the postsubcardinal anastomosis, then through the subcardinal-hepatic anastomosis to the hepatic segment of the IVC.

This process establishes the prerenal division of the IVC.



The next major development is the appearance of the paired supracardinal veins,which lie dorsomedial to the posterior cardinal veins and dorsolateral to the aorta.

Initially, multiple anastomoses form between the posterior and supracardinal veins.

On each side, a suprasubcardinal anastomosis develops from union of the postsupracardinal and the postsubcardinal anastomoses.

In addition, intersupracardinal anastomoses develop dorsal to the aorta.

The supracardinal veins then separate into cranial (azygos) and caudal (lumbar) ends.



Meanwhile, inferiorly, anastomoses develop between the two posterior cardinal veins and between the posterior and lumbar supracardinal veins.

With further atrophy of the posterior cardinal veins, blood return from the lower extremities is shunted through the supracardinal system to the suprasubcardinal anastomosis, then to the prerenal division of the IVC.

In addition, blood return from the left side of the body is shunted to the right across the intersupracardinal and interpostcardinal anastomoses.

Finally, the left supracardinal vein is one of the last veins to disappear, although Huntington and McLure (4state that the vessel does not so much atrophy as become incorporated into the right supracardinal vein by coalescence of the multiple anastomoses.


EMBRYOGENESIS OF THE IVC In summary, the normal IVC is composed of four

segments: hepatic, suprarenal, renal, and infrarenal.

The hepatic segment is derived from the vitelline vein.

The right subcardinal vein develops into the suprarenal segment by formation of the subcardinal-hepatic anastomosis.


The renal segment develops from the right suprasubcardinal and postsubcardinal anastomoses.

It is generally accepted that the infrarenal segment derives

from the right supracardinal vein, although this idea is somewhat controversial .

In the thoracic region, the supracardinal veins give rise to the azygos and hemiazygos veins.

In the abdomen, the postcardinal veins are progressively replaced by the subcardinal and supracardinal veins but persist in the pelvis as the common iliac veins.


Since the embryonic ureter passes posterior to the posterior cardinal veins and anterolateral to the supracardinal vein, formation of the postsupracardinal anastomosis inferiorly and the suprasubcardinal anastomosis at the level of the kidney allows development of a potential periureteric venous ring.

The renal collar is formed from the intersupracardinal anastomosis dorsally, the intersubcardinal anastomosis and postsubcardinal anastomoses ventrally, and the suprasubcardinal anastomosis laterally. The embryonic kidneys are initially drained by paired ventral and dorsal limbs.

Ordinarily, both dorsal limbs regress.

On the right side, the ventral limb is incorporated into the lateral wall of the renal segment of the IVC.

On the left side, the ventral limb and the anterior limb of the renal collar form the normal adult left renal vein.


THANK YOU

congenital anomalies of ivc

Education