Ductus venosus
The ductus venosus (also Ductus venosus Arantii or Ductus Arantii ) is a fetal short-circuit connection between the left umbilical vein and the inferior vena cava ( inferior vena cava in humans, in animals referred to as the "posterior vena cava", caudal vena cava ). Before birth, about 50% of the umbilical vein blood is passed directly into the vena cava, bypassing the liver circulation. The blood is accelerated through the constriction of the ductus venosus, so that the faster, more oxygen-rich blood than the blood from the hepatic veins hits the septum secundum and from this primarily supplies the body circulation through the foramen ovale , bypassing the pulmonary circulation .
In many mammals , the ductus venosus closes before birth. In humans, dogs , cats and ruminants , however, it is still open at birth and normally closes in the first days of life. After closure, the venous ligament remains as a deserted residue.
Persistent ductus venosus
If this closure does not take place, one speaks of a persistent ductus venosus . The portal blood then continues to flow directly into the vena cava ( portosystemic or portocaval shunt ) , bypassing the liver circulation . As a result, pollutants absorbed in the intestine can get directly into the body's circulation and are no longer immediately detoxified by the liver, which in the long term can lead to central nervous disorders ( hepatoencephalopathy ). Life expectancy can be severely limited. A surgical ( ligature of Shuntgefäßes) or radiological interventional treatment ( embolization of Shuntgefäßes) can improve the liver blood flow and thus to prevent further complications shuntbedingter.
literature
- Uwe Gille: Cardiovascular and immune system, Angiologia. In: Franz-Viktor Salomon u. a. (Ed.): Anatomy for veterinary medicine . Enke-Verlag, Stuttgart 2004, ISBN 3-8304-1007-7 , pp. 404-463.
Individual evidence
- ↑ a b K. L. Moore et al .: Before we are born - essentials of embryology and birth defects. 2012, ISBN 978-1-4377-2001-3 , p. 215.