Our body has a very well-designed circulatory system. In the event of problems in any of the departments, collateral circulation is activated , which is caused by the presence of anastomoses. In addition, these collaterals sometimes determine the clinical symptoms of certain diseases.
Human venous vessels are divided into three large groups: the portal vein system, the lower and upper vena cava. Each of these groups carries out the outflow of blood from certain areas of the body. Between them there are a number of compounds, which are called portocaval and cava caval anastomoses. Therefore, if, for example, a blockage of a vein occurs in one of the systems, then due to the presence of bypasses, the venous outflow will be preserved.
Now consider in more detail portocaval anastomoses. They are the connections of the portal vein (v. Porta) and the lower or superior vena cava (v. Cava inferior et superior) and have the following localization:
- lower esophagus. Blood from the portal vein enters the veins of the stomach, which are widely anastomosed with the esophagus. Esophageal veins, in turn, flow into the unpaired and semi-unpaired veins that flow to v. cava superior;
- the rectum. The outflow of blood is carried out in three sources from its upper, middle and lower parts. Blood flows from the upper section to the inferior mesenteric vein, from the middle to the internal iliac vein and, finally, from the lower to the internal genital (further into the internal iliac). Naturally, in the thickness of the rectum, they all connect and form portocaval anastomoses;
- the front wall of the abdomen (around the umbilical ring). A complex anastomosis, the sources of which are the veins of all three systems. The portal vein is represented by the umbilical veins, which are located in the round ligament of the liver. From the superior vena cava, the superior epigastric is included in the anastomosis, and the inferior epigastric vein from the inferior vena cava;
- capsule of the kidney. In this area, the connection of the inferior mesenteric vein (from the portal vein) and renal veins (from the inferior vena cava) occurs.
I must say that there are not only portocaval anastomoses. In certain places, the superior and inferior vena cava join. Such compounds are called cava caval anastomoses. There are three of them:
- anterior abdominal wall. In addition to anastomoses with portal vein, the lower and upper hollows are also widely connected to each other;
- vertebral plexus. In the upper spine, the veins of this area anastomose with the veins of the head and neck from the superior vena cava, and in the lower part with the lumbar veins from the inferior vena cava. Thus, the anastomosis is formed through the vertebral plexus;
- lower back. Lumbar veins (inferior vena cava) and unpaired and semi-unpaired veins (superior vena cava).
The significance of the outflow bypasses is undeniable. For example, with portal hypertension syndrome, portocaval anastomoses play an important diagnostic role. The fact is that in the presence of this pathology, many of the clinical manifestations are associated with them. There is bleeding from the dilated veins of the esophagus, as well as from the rectum. A classic symptom is a βjellyfish headβ. It manifests itself on the anterior abdominal wall and is an enlarged anastomosing vein. All this is due to the fact that due to increased pressure in the portal vein, blood flows through all the paths available to it. The causes of portal hypertension syndrome are liver diseases, for example, cirrhosis, hepatitis, tumor lesions, etc.
Thus, the presence of anastomoses is a very important point in the functioning of the body. They play an exceptional role in many pathological processes and are extremely important both for the body to independently solve various problems, and for the diagnosis of some pathologies.