Inferior Vena Cava
The inferior vena cava is formed at the level of the fifth lumbar
vertebra, a little to the right of the midline (Fig. 4.91). It ascends the posterior abdominal
wall and pierces the central tendon of the diaphragm to enter the thorax at the
level of the eighth thoracic vertebra (Fig. 4.92).
Behind the inferior vena cava lie the lumbar vertebral bodies, the
anterior longitudinal ligament, the right sympathetic chain and right psoas
major muscle. In addition, the right renal and right lumbar arteries cross
behind the vena cava (Figs 4.88 & 4.89) and most of the right suprarenal
gland lies posterior to the vessel (Fig. 4.92).
Near its commencement, the inferior vena cava is covered
anteriorly by peritoneum and coils of small intestine. Superiorly, it is
crossed by the root of the mesentery, the right gonadal artery (Fig. 4.88) and
the third part of the duodenum (Fig. 4.52). It continues behind the omental
foramen (Fig. 4.38) and then grooves the posterior surface of the liver (Fig.
4.58) before piercing the diaphragm.
To the right of the vena cava lie the gonadal vessels, the ureter,
the kidney and renal vessels (Fig. 4.91) and the right lobe of the liver. To
the left lie the aorta with its associated lymph nodes, the right crus of the
diaphragm and the caudate lobe of the liver.
Tributaries
The venous drainage of the suprarenal glands, the kidneys and the
gonads is asymmetric. On the right, each of these organs is drained by a vein
that passes directly into the inferior vena cava (Figs 4.91 & 4.92) but on
the left, the renal vein receives the suprarenal and gonadal veins before
crossing in front of the aorta to reach the vena cava. Immediately before its
passage through the diaphragm the inferior vena cava receives several large
hepatic veins (Fig. 4.92).
The parietal tributaries of the inferior vena cava drain the
diaphragm and the posterior pelvic and abdominal walls. The lumbar and median
sacral veins (Figs 4.88 & 4.90) accompany the corresponding arteries, the
upper lumbar veins often communicating with the renal, suprarenal, azygos and
hemiazygos veins. Two or more inferior phrenic veins drain the undersurface of
the diaphragm (Fig. 4.92).
