In the course of the round ligament of the liver, small paraumbilical veins are found which establish an

anastomosis An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal (su ...

between the

vein Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and feta ...

s of the

anterior abdominal wall In anatomy, the abdominal wall represents the boundaries of the abdominal cavity. The abdominal wall is split into the anterolateral and posterior walls. There is a common set of layers covering and forming all the walls: the deepest being the v ...

and the

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. Approxima ...

, hypogastric, and

iliac vein In human anatomy, iliac vein refers to several anatomical structures located in the pelvis: * Common iliac vein, formed by the external and internal iliac veins, drains into the inferior vena cava * Deep circumflex iliac vein, formed by the union ...

s. These veins include Burrow's veins, and the veins of Sappey – superior veins of Sappey and the inferior veins of Sappey. The best marked of these small veins is one which commences at the

navel The navel (clinically known as the umbilicus; : umbilici or umbilicuses; also known as the belly button or tummy button) is a protruding, flat, or hollowed area on the abdomen at the attachment site of the umbilical cord. Structure The u ...

(umbilicus) and runs backward and upward in, or on the surface of, the round ligament (ligamentum teres) between the layers of the

falciform ligament In human anatomy, the falciform ligament () is a ligament that attaches the liver to the front body wall and divides the liver into the left lobe and right lobe. The falciform ligament is a broad and thin fold of peritoneum, its base being dire ...

to end in the left portal vein.

Pathophysiology

In cases of

portal hypertension Portal hypertension is defined as increased portal venous pressure, with a hepatic venous pressure gradient greater than 5 mmHg. Normal portal pressure is 1–4 mmHg; clinically insignificant portal hypertension is present at portal pressures 5� ...

, the paraumbilical veins may become enlarged in order to reduce hepatic portal vein pressure by shunting blood to the

superficial epigastric vein The superficial epigastric vein is a vein Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; ex ...

. The superficial epigastric vein drains to the femoral vein which ultimately drains into the inferior vena cava directly through the external iliac and common iliac vein, thereby bypassing the liver. Dilation of this particular

portacaval anastomosis A portacaval anastomosis or portocaval anastomosis is a specific type of circulatory anastomosis that occurs between the veins of the portal circulation and the vena cava, thus forming one of the principal types of portasystemic anastomosis or po ...

results in what is referred to as

caput medusae Caput medusae is the appearance of distended and engorged superficial epigastric veins, which are seen radiating from the umbilicus across the abdomen. The name ''caput medusae'' (Latin for "head of Medusa") originates from the apparent simil ...

References

External links

* - "Venous Drainage of the Anterior Abdominal Wall" Veins of the torso {{circulatory-stub