This document discusses the normal anatomy and common congenital anomalies of the superior and inferior vena cavae. It begins with an overview of the embryological development of the vena cavae. It then describes the normal anatomy of the superior and inferior vena cavae and their major tributaries. Common congenital anomalies are then outlined, including double superior vena cavae, left-sided superior vena cava, left inferior vena cava, double inferior vena cava, azygos continuation of the inferior vena cava, and circumcaval anomalies of the left renal vein and ureter. Clinical significance is discussed for some anomalies.

1. Normal anatomy and Congenital
anomalies of Vena cavae
Dr. Gobardhan Thapa
Resident, MD Radiodiagnosis
NAMS, Bir hospital,
Kathmandu, Nepal

2. Presentation outline
• Embryology of the vena cavae
• Anatomy of the vena cavae
– Superior vena cava
– Inferior vena cava
• Congenital anomalies of the vena cavae

3. Vena cavae
• Vena cava
– largest veins that return deoxygenated blood into
the heart
• Two vena cavae
– superior vena cava
– Inferior vena cava

4. Embryology of the vena cavae

5. Embryology of the vena cava
• Veins of the body develop
from three primitive veins
1. Viteline vein-drain from
yolk sac
2. Umblical vein- drain from
the placenta
3. Common cardinal vein-
return poorly oxygenated
blood from the body of
the embryo

6. Development of the superior vena
cava
• First part: right anterior
cardinal vein caudal to
oblique transverse
anastomosis
• Second part: right
common cardinal vein
(right duct of Cuvier)

7. • Initially,
– Vitelline veins: drain the
viscera to the Yolk sac
– Posterior cardinal veins:
drain the body wall
caudal to the heart
• 6-8 weeks:
development of the
infrahepatic IVC
segments from 3 pairs
of primitive veins
• Infrahepatic IVC
– Posterior cardinal veins
– Subcardinal veins
– Supracardinal veins
Development of inferior vena cava

8. Development of inferior vena cava
Normal IVC from 4 segments:
• Hepatic: from the vitelline
vein
• Suprarenal: from the right
subcardinal vein (via
subcardinal-hepatic
anastomosis)
• Renal: right supracardinal
and subcardinal
anastomosis
• Infrarenal: right
supracardinal vein

9. •Azygos and hemiazygos veins develop from the
cranial aspect of the supracardinal veins
• In abdomen, posterior cardinal veins are replaced by
Subcardinal and supracardinal veins
• In pelvis, the posterior cardinal veins persist as
common iliac veins

10. Normal Anatomy

11. Superior vena cava (SVC)
• formed by the junction of
– the short, vertically oriented right and
– the longer obliquely oriented left brachiocephalic
veins
at the level of T-1
• The third tributary to the SVC is the azygos vein, which
enters the dorsal aspect of the SVC at its midpoint
• SVC contains no valves
• Length: approx 7 cm
• usually less than 2 cm in diameter

12. Superior vena cava: Gross anatomy
Beginning: at the level of first right
costal cartilage
Course: Descend vertically behind the
2nd and 3rd ICS
End: Ends into right atrium at the level
of right 3rd costal cartilage
Lower half is covered by the parietal
pericardium and its wall is partially
composed of visceral pericardium
Tributaries:
• Azygos vein
• Small veins draining pericardium and
other mediastinal structures

13. Relations
• Ventrally: mediastinal fat,
pleura, thymus, and the
adjacent right lung
• Posteriorly: innominate
artery, trachea, right main
bronchus, right main
pulmonary artery, right
superior pulmonary vein
and vagus nerve
• Large number of adjacent
lymph nodes, mostly in its
dorsal aspect

14. Inferior vena cava (IVC)
• formed by the junction of
– right and left common iliac
veins
– at L-5
• ascends on the right of the
abdominal aorta and anterior to
the spine to enter the right
atrium (RA) at about T-8
• The main tributaries of the IVC
are the hepatic (T-10), renal (L-2),
right adrenal and gonadal and
lumbar veins

15. Inferior vena cava: course
Abdominal:
-Retroperitoneal
-run along the side of vertebral
column
-Various other veins drain into
IVC along its course

16. Thoracic
-Pierce the diaphragm at
T-8 level
-Short thoracic course
before draining into right
atrium
• Normal diameter:1.5-
2.5cm

17. Tributaries
• T8: Paired inferior phrenic veins
• T8: Hepatic veins - 3
• L1: Right suprarenal vein
• L1: Renal vein
• L2: Right gonadal veins
• L1-L5: Lumbar veins
• L5: Common iliac veins (origin)

18. Relation of the abdominal part of the
inferior venecava
Anteriorly:
• first part of duodenum
• common bile duct
• portal vein
• head of pancreas
• right gonadal artery
• root of mesentery
• Right common iliac artery

19. Posteriorly:
• The lower three lumbar
vertebral bodies
• Their intervertebral disc
• Right psoas major
• Sympathetic trunk
• Right crus of the
diaphragm
• The medial part of the
suprarenal gland
• Right coeliac ganglion

20. Right:
• The right ureter
• The second part of the
duodenum
• Medial border of right
kidney
• The right lobe of the liver
Left:
• Aorta
• The right crus of the
diaphragm
• The caudate lobe of the
liver

21. Congenital anomalies
Superior vena cava
1) Double SVC
2) Left sided SVC
3) others
Inferior vena cava
1) Left IVC
2) Double IVC
3) Azygos continuation of
the IVC
4) Circumaortic left renal
vein
5) Retroaortic left renal
vein
6) Circumcaval ureter
7) others

22. Congenital anomalies of the SVC

23. Double or Bilateral SVC
• Commonest systemic venous
anomaly (present in about 10% of
patients with congenital heart
disease)
• Results from failure of the
embryonic left anterior cardinal
vein to regress
• only about half of these are large
enough – of hemodynamic
significance

24. Double SVC
• Drainage is variable and can be to:
– coronary sinus
– right atrium: via oblique vein of Marshall
– left atrium
• Anastomosis may be present in
between the two cavas

25. Double SVC
Fig. schematic diagrams of double SVC
(SVC – superior vena cava, CS – coronary sinus, RA- right atrium, LA – left atrium)

26. Radiological identification
• Can not be diagnosed
easily in plain chest
radiographs
• Generally recognized in
echocardiograms
• Condition signalled by an
unusually large coronary
sinus entering the right
atrium
• Definitive diagnosis:
angiography of MRI

27. Double SVC
Fig. CT images cranial to caudal depicting the
anomaly.
R SVC = right SVC, LSVC = left SVC, CS = coronary
sinus

28. Left SVC
• Results from failure of the
embryonic left anterior
cardinal vein to regress
associated with the
regression of right
anterior cardinal vein
• Overall incidence: ranges
from 1 per 330 to 1 per
750 normal individuals
and 1 per 25 patients
with congenital heart
disease

29. Left SVC
• Mostly drain to right atrium
(coronary sinus)
• Most commonly associated
with Atrial septal defect
• Other associated cardiac
anomalies are Single atrium,
VSD, PDA, tetalogy of Fallot
• Higher incidence of Left SVC
with partial transposition of
viscera

30. Left SVC
Left Sided Superior Vena Cava
A chest radiograph demonstrates abnormal position of the central venous
catheter (red arrow). Blood gas analysis and contrast injection confirmed
catheter position within a left-sided superior vena cava. Ao, aortic knob

31. Clinical significance
• Not normally of clinical significance
• Surgically important in correct
placement of venous connections in
case of cardiopulmonary bypass
• Positive benefit in some complex
procedures for construction of the
final repair

32. Other anomalies of the right SVC
Rare
• Right SVC draining into
the RA via a low
insertion
• Congenital aneurysm of
SVC (saccular and
Fusiform types)

33. Congenital anomalies of the IVC

34. Left IVC
• Results from the regression
of right supracardinal vein
with persistence of left
supracardinal vein
• prevalence: 0.2-0.5%
• Left IVC ends at left renal
vein – then, crosses anterior
to aorta, uniting with right
renal vein – from a normal
right sided prerenal IVC

35. Fig. Left IVC
CT images caudal to cranial depict the anomaly

36. Clinical significance
• Potential for misdiagnosis as left
sided paraaortic adenopathy
• Spontaneous rupture of abdominal
aortic aneurysm into left IVC has
been reported
• Transjugular access to the infrarenal
IVC for placement of an IVC Filter
may be difficult

37. Double IVC
• Results from
persistence of both
supracardinal veins
• Prevalence: 0.2-3 %
• Left IVC typically ends
at the left renal vein -
which crosses anterior
to the aorta in the
normal fashion – then
joins the right IVC

38. Fig. Double IVC
CT scan caudal to cranial images depicting the anomaly

39. Double IVC
Duplication of the lnferior Vena Cava
A. lnferior vena cavagram demonstrates the right component of the inferior vena cava(IVC) with a
large inflow from the left renal vein (arrowheads). The left iliac vein did not fill on this injection
B. Contrast injection into the left femoral vein opacifies the left IVC (LIVC), which joins the right IVC
by draining through the left renal vein (LRV arrowheads). RRV (right renal vein)

40. Clinical significance
• Should be suspected in cases of
recurrent pulmonary embolism
following placement of an IVC filter
• Misdiagnosis as lymphadenopathy

41. Azygos continuation of the IVC
• Failure to form the right
subcardinal-hepatic
anastomosis, with resultant
atrophy of the right
subcardinal vein
• Prevalence: 0.6%
• The azygos vein joins the SVC
at the normal location (at the
level of T4 posteriorly)
• Dilatation of azygos vein,
azygos arch and the SVC
• Each gonadal vein drain to the
ipsilateral renal vein

42. Clinical significance
• Avoid misdiagnosis as right paratracheal
mass or retrocrural adenopathy
(enlarged azygos vein at the confluence
with the SVC)
• Preoperative knowledge of the anatomy
important in planning cardiopulmonary
bypass and to avoid difficulties in
catheterizing the heart

43. Circumaortic left renal vein
• Results from the persistence of the
dorsal limb of the embryonic left
renal vein and of the dorsal arch of
the renal collar (intersupracardinal
anastomosis)
• prevalence: 8.7 %
• Two renal veins are present
• The superior renal vein receives
the left adrenal vein and crosses
the aorta anteriorly
• Inferior renal vein receives the left
gonadal vein and crosses
posterior to the aorta
approximately 1-2 cm inferior the
normal anterior vein

44. Circumaortic left renal vein
Fig. Renal vein collar
Selecive injection of upper (anterior) renal vein with retrograde filling
of lower (retroaortic limb)

45. Clinical significance
• Preoperative planning prior to
nephrectomy and in renal vein
catheterization for venous sampling
• Misdiagnosis as retroperitoneal
adenopathy

46. Retro aortic left renal vein
• Persistence of the dorsal
arch of the renal collar
with regression of the
ventral arch – single renal
vein passes posterior to
the aorta
• Prevalence: 2.1%

47. Retro aortic left renal vein
Fig. CT scans show the left renal vein (arrow) descending to cross
posterior to the aorta

48. Clinical significance
• Preoperative recognition of the anomaly
• Posterior nutcracker syndrome
– an unusual cause of unexplained episodes of
microscopic or macroscopic hematouria with or
without flank pain in the absence of glomerular
disease.
– Arises due to compression of a retroaortic left renal
vein between the aorta and the vertebral body,
causing venous hypertension, hematuria, and left
gonadal vein varicocele

49. Circumcaval ureter
• Also termed as a retrocaval
ureter
• Right supracardinal system fails
to develop, whereas the right
posterior cardinal vein persists
• Almost always on the right side
• Proximal ureter courses
posterior to the IVC, then
emerges to the right of aorta,
coming to lie anterior to the
right iliac vessels
• Patient may develop partial
ureteral obstruction or recurrent
urinary tract infections

50. Circumcaval ureter
Fig. CT scans presented from
cranial to caudal show the
anomaly. The right ureter
(arrow) is positioned posterior
to the IVC. The ureter (arrow)
then courses to the left of the
IVC. Finally, the ureter (arrow)
crosses anterior to the
IVC

51. Other anomalies
• Absence of the
infrarenal IVC or the
entire IVC
• Coexistence of more
than one anomaly
Fig. absent infrarenal IVC with collateral
flow from the lower extremities
reaching the azygos system via
paravertebral collateral veins

53. Reference
• Anatomy for diagnostic Imaging, Ryan, 3/e
• Textbook of Radiology and Imaging, Sutton, 7/e
• Fundamentals of diagnostic radiology, Brant and
Helms, 4/e
• Congenital anomalies of the Superior vena cava:
A CT study; Cormier et al, Seminars in
Roentgenology, April 1989
• Spectrum of congenital anomalies of the Inferior
vena cava: Cross sectional imaging findings; Bass
et al, RadioGraphics 2000