Inferior Vena Caval System 15
Ciro Stavolo, Raffaella Marino
L. Romano, M. Silva, S. Fulciniti, A. Pinto (eds.) MDCT Anatomy – Body 105 © Springer-Verlag Italia 2011 106 C. Stavolo, R. Marino
Inferior vena cava
Confluence of the common iliac vein
a
Right common iliac artery Left common iliac artery
Right common Left common iliac vein iliac vein
b
Right common iliac vein Left common iliac vein
c Fig. 15.1 a The inferior vena cava is the largest venous trunk of the abdominal cavity. It returns poor- ly oxygenated blood from the inferior limbs, pelvis, back, abdominal organs, and viscera to the right atrium. Blood from the gastrointestinal tract passes through the portal venous system before entering the inferior vena cava, through the liver parenchyma and suprahepatic veins. b The two common iliac veins join at the level of the 5° lumbar vertebra, forming an acute angle before drain- ing into the inferior vena cava. At the same level, the common iliac arteries form a characteristic downwards-pointing Y shape and cross the confluence of the common iliac veins. c The common iliac veins are located near the corresponding arteries. They receive poorly oxygenated blood from the lower extremities, pelvic muscles, and pelvic urogenital organs 15 Inferior Vena Caval System 107
Suprahepatic veins
Inferior vena cava
a
Right renal Superior venous confluence mesenteric vein
b
Confluence of the inferior vena cava and right renal vein
c
Fig. 15.2 a The inferior vena cava passes through the posterior abdominal compartment, in the ex- traperitoneal perivascular space, near the abdominal aorta and spinal column. After receiving blood from the three suprahepatic veins, it continues through the diaphragmatic hiatus, at the dorsal ver- tebral level. The branches of the inferior vena cava correspond to those of the abdominal aorta. b At the level of the 2° lumbar vertebra, the right renal vein drains directly into the inferior vena cava. The left renal vein is both larger and longer than the right. It crosses the abdominal aorta and then drains into the inferior vena cava. c The right renal vein has a very short course. The inferior and superior venae cavae are connected through the azygos lumbar veins 108 C. Stavolo, R. Marino
Lumbar vein
a
Hepatic veins
Portal vein Inferior (origin) vena cava
b
Portal vein Hepatic hilum
Inferior vena cava Splenic vein
c
Fig. 15.3 a The lumbar veins are paired tributaries of the inferior vena cava and parallel the corre- sponding arteries. They closely cross the lumbar spine. b The main suprahepatic trunks form in the liver parenchyma and carry hypo-oxygenated blood from the liver parenchyma (resulting from the portal and hepatic arterial supplies) directly into the inferior vena cava. The suprahepatic veins di- vide into three major trunks (left, right, and median) and several minor trunks. c At the hepatic hilum, the inferior vena cava is localized behind the portal vein 15 Inferior Vena Caval System 109
Right suprahepatic vein Left suprahepatic vein
Right portal vein
Right renal vein
a
Transdiaphragmatic vena caval tract Suprahepatic veins (major and minor trunks)
b
Median suprahepatic vein Right suprahepatic vein
Left suprahepatic vein
c
Fig. 15.4 a The three major suprahepatic trunks have short stems and drain directly into the anteri- or surface of the vena caval wall, at the level of the hepatic dome surface, immediately before the vena cava passes through the diaphragm and merges into the right atrium. b The minor suprahep- atic veins are completely surrounded by liver parenchyma. They are longer, thinner, and more nu- merous (10-15) than the major veins. c The right suprahepatic trunk is obliquely oriented and col- lects blood from the right hepatic lobe. The left and median suprahepatic trunks collect blood from the lateral hepatic lobe and fourth hepatic segment, respectively. The caudate lobe has a proper ve- nous system, with blood flowing directly into the lumen of the inferior vena cava