HOME

TheInfoList



OR:

In
human anatomy The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a hea ...
, the hepatic veins are the
vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated ...
s that drain venous
blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...
from the
liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...
into the
inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...
(as opposed to the
hepatic portal vein The portal vein or hepatic portal vein (HPV) is a blood vessel that carries blood from the gastrointestinal tract, gallbladder, pancreas and spleen to the liver. This blood contains nutrients and toxins extracted from digested contents. Appr ...
which conveys blood from the gastrointestinal organs to the liver). There are usually three large upper hepatic veins draining from the left, middle, and right parts of the liver, as well as a number (6-20) of lower hepatic veins. All hepatic veins are valveless.


Structure

All the hepatic veins drain into the
inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...
. The hepatic veins are divided into an upper and a lower group.


Upper group

The upper group consists of three hepatic veins - the right, middle, and left hepatic veins - draining the central veins from the right, middle, and left regions of the liver and are larger than the lower group of veins. The veins of the upper group drain into the suprahepatic part of the inferior vena cava (i.e. part superior to the liver).


Right hepatic vein

The right hepatic vein is the longest and largest of all the hepatic veins. It drains the liver segments VI and VII in their entirety, and variably participates in the drainage of segments V and VIII; the extent of drainage of the latter two segments by the right hepatic veins as opposed to the middle hepatic vein and possible variant accessory veins determines the calibre of the right hepatic vein. It arises anteriorly near the inferior border of the liver, coursing along the right portal fissure to drain into the inferior vena cava near the superior margin of the caudate lobe. It usually reaches the inferior vena cava as a single vessel, but sometimes drains into it as two separate trunks.


Middle hepatic vein

The middle hepatic vein drains the central portion of the liver, draining segments IV, V, and VIII. The middle hepatic vein most often joins the left hepatic vein to form a short common trunk to drain jointly into the inferior vena cava; the middle hepatic vein drains into the inferior vena cava as a separate vessels in less than 10% of individuals.


Left hepatic vein

The left hepatic vein usually drains liver segments II and III, and occasionally also segment IV. The umbilical fissue vein is a major tributary of the left hepatic vein. The left hepatic vein most often forms a short common trunk with the middle hepatic vein before these jointly drain into the inferior vena cava.


Lower group

The lower group consists of 6-20 smaller hepatic veins which drain the
right lobe In human anatomy, the liver is divided grossly into four parts or lobes: the right lobe, the left lobe, the caudate lobe, and the quadrate lobe. Seen from the front – the diaphragmatic surface - the liver is divided into two lobes: the right ...
and the
caudate lobe In human anatomy, the liver is divided grossly into four parts or lobes: the right lobe, the left lobe, the caudate lobe, and the quadrate lobe. Seen from the front – the diaphragmatic surface - the liver is divided into two lobes: the right ...
, are in contact with the hepatic tissue, and are valveless. All veins of the lower group drain into the retrohepatic part of the inferior vena cava (i.e. part posterior to the liver). The lower group consists of 1-5 veins draining the liver segment I, and may consist of (inconsistently present) accessory inferior hepatic vein, accessory middle right hepatic vein, and several smaller retrohepatic veins draining the right lobe of the liver.


Clinical significance

The hepatic veins (and their variant anatomy) are relevant in liver resection and transplantation, and in
Budd–Chiari syndrome Budd–Chiari syndrome is a very rare condition, affecting one in a million adults. The condition is caused by occlusion of the hepatic veins that drain the liver. It presents with the classical triad of abdominal pain, ascites, and liver enlar ...
.
Budd–Chiari syndrome Budd–Chiari syndrome is a very rare condition, affecting one in a million adults. The condition is caused by occlusion of the hepatic veins that drain the liver. It presents with the classical triad of abdominal pain, ascites, and liver enlar ...
is a condition caused by blockage of the hepatic veins, such as by a
blood clot A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cr ...
. It presents with a "classical triad" of abdominal pain, ascites, and liver enlargement. It occurs in 1 out of a million individuals. The syndrome can be fulminant, acute, chronic, or asymptomatic. The independent lower veins draining the liver segment I directly into the inferior vena cava are unaffected by obstruction of the large hepatic veins, leading to compensatory hypertrophy. The hepatic veins may be connected with the portal veins in a TIPS procedure.


Additional images

File:Volume rendered CT scan of abdominal and pelvic blood vessels (smaller).gif, Animated Volume rendered CT scan of abdominal and pelvic blood vessels. Gray1121.png, Posterior abdominal wall, after removal of the peritoneum, showing kidneys, suprarenal capsules, and great vessels. (Hepatic veins labeled at center top.) File:Gray476.png, Human embryo with heart and anterior body-wall removed to show the sinus venosus and its tributaries. File:Gray1089.png, Longitudinal section of a hepatic vein. File:Slide7cccc.JPG, Hepatic vein File:Hepatic Venous Pulse.png, Normal spectral Doppler waveform of hepatic venous flow


References


External links


Hepatic veins
-
Ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...
- University of the Health Sciences in Bethesda, Maryland {{Authority control Veins of the torso