Paraumbilical veins
Encyclopedia
In the course of the round ligament of liver
and of the median umbilical ligament
, small veins (parumbilical) are found which establish an anastomosis
between the veins of the anterior abdominal wall and the hepatic portal
, hypogastric
, and iliac vein
s.
The best marked of these small veins is one which commences at the umbilicus
and runs backward and upward in, or on the surface of, the round ligament (ligamentum teres) between the layers of the falciform ligament
to end in the left portal vein.
, the paraumbilical veins may become enlarged in order to reduce hepatic portal vein pressure by shunting blood to the inferior epigastric vein
. Dilation of this particular portacaval anastomosis
results in what is referred to as caput medusae
.
Round ligament of liver
In anatomy, the round ligament of liver is a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver...
and of the median umbilical ligament
Median umbilical ligament
The median umbilical ligament is a structure in human anatomy. It is a shrivelled piece of tissue that represents the remnant of the embryonic urachus.It extends from the apex of the bladder to the umbilicus, on the deep surface of the anterior abdominal wall...
, small veins (parumbilical) are found which establish an anastomosis
Anastomosis
An anastomosis is the reconnection of two streams that previously branched out, such as blood vessels or leaf veins. The term is used in medicine, biology, mycology and geology....
between the veins of the anterior abdominal wall and the hepatic portal
Hepatic portal vein
The hepatic portal vein is not a true vein, because it does not conduct blood directly to the heart. It is a vessel in the abdominal cavity that drains blood from the gastrointestinal tract and spleen to capillary beds in the liver...
, hypogastric
Hypogastric
Hypogastric can refer to:* The hypogastrium, a region of the abdomen* The "hypogastric artery", an old name for the internal iliac artery* The "hypogastric vein", an old name for the internal iliac vein...
, and iliac vein
Iliac vein
In human anatomy, iliac vein refers to several anatomical structures located in the pelvis:*External iliac vein - terminates at the common iliac vein, drains the femoral vein....
s.
The best marked of these small veins is one which commences at the umbilicus
Navel
The navel is a scar on the abdomen caused when the umbilical cord is removed from a newborn baby...
and runs backward and upward in, or on the surface of, the round ligament (ligamentum teres) between the layers of the falciform ligament
Falciform ligament
The falciform ligament is a ligament that attaches the liver to the anterior body wall.It is a broad and thin antero-posterior peritoneal fold, falciform in shape, its base being directed downward and backward and its apex upward and backward...
to end in the left portal vein.
Pathophysiology
In patients with portal hypertensionPortal hypertension
In medicine, portal hypertension is hypertension in the portal vein and its tributaries.It is often defined as a portal pressure gradient of 10 mmHg or greater.-Causes:Causes can be divided into prehepatic, intrahepatic, and posthepatic...
, the paraumbilical veins may become enlarged in order to reduce hepatic portal vein pressure by shunting blood to the inferior epigastric vein
Inferior epigastric vein
In human anatomy, inferior epigastric vein refers to the vein that drains into the external iliac vein and arises from the superior epigastric vein...
. Dilation of this particular portacaval anastomosis
Portacaval anastomosis
A portacaval anastomosis is a specific type of anastomosis that occurs between the veins of portal circulation and those of systemic circulation....
results in what is referred to as caput medusae
Caput medusae
Caput medusae is the appearance of distended and engorged paraumbilical veins, which are seen radiating from the umbilicus across the abdomen to join systemic veins...
.