The liver is a vital gland of human external secretion. Its main functions include the neutralization of toxins and their removal from the body. In the case of liver damage, this function is not performed and harmful substances enter the bloodstream. With the flow of blood, they flow through all organs and tissues, which can lead to serious consequences.
Since there are no nerve endings in the liver, a person may not even suspect for a long time that there is any disease in the body. In this case, the patient goes to the doctor too late, and then the treatment no longer makes sense. Therefore, you must carefully monitor your lifestyle and regularly undergo preventive examinations.
Liver anatomy
According to the classification, the liver is divided into independent segments. Each is connected to the vascular inflow, outflow, and bile duct. In the liver, the portal vein, the hepatic artery, and the bile duct are divided into branches, which in each segment gather into veins.
The venous system of the organ is constituted by the vessels leading and draining blood. The main adductive vein functioning in the liver is the portal vein. The hepatic veins belong to the discharge. Sometimes there are cases when these vessels independently flow into the right atrium. Basically, the veins of the liver flow into the inferior vena cava.
The permanent venous vessels of the liver include:
- right vein;
- middle vein;
- left vein;
- vein of the caudate lobe.
Gantry
The portal or portal vein of the liver is a large vascular trunk that collects blood that passes through the stomach, spleen, and intestines. After collection, it delivers this blood to the lobes of the liver and transfers the already purified blood back to the general channel.
Normally, the length of the portal vein is 6-8 cm, and its diameter is 1.5 cm.
This blood vessel takes its origin behind the head of the pancreas. Three veins merge there: the inferior mesenteric vein, superior mesenteric vein and splenic vein. They make up the roots of the portal vein.
In the liver, the portal vein is divided into branches diverging in all hepatic segments. They accompany branches of the hepatic artery.
Blood, which is carried by the portal vein, nourishes the organ with oxygen, delivers vitamins and minerals into it. This vessel plays an important role in digestion and detoxifies the blood. In the event of a malfunction of the portal vein, serious pathologies arise.
Diameter of hepatic veins
The largest of the vessels of the liver is the right vein, the diameter of which is 1.5-2.5 cm. It flows into the lower hollow in the region of its anterior wall near the opening in the diaphragm.
Normally, the hepatic vein, formed by the left branch of the portal vein, flows at the same level as the right, only on the left side. Its diameter is 0.5-1 cm.
The diameter of the vein of the caudate lobe in a healthy person is 0.3-0.4 cm. Its mouth is slightly lower than the place where the left vein flows into the inferior vena cava.
As you can see, the size of the hepatic veins differ.
The right and left, passing in the liver, collect blood from the right and left hepatic lobes, respectively. Middle and caudate lobe vein - from the same lobes.
Hemodynamics in portal vein
According to the course of anatomy, arteries pass in many organs of the human body. Their function is to saturate the organs with the substances they need. Arteries bring blood to the organs, and remove its veins. They transport processed blood to the right side of the heart. This is how the large and small circles of blood circulation work. The hepatic veins play a role in it.
The portal system functions specifically. The reason for this is its complex structure. Many branches to the venules and other bloodstream channels leave the main trunk of the portal vein. That is why the portal system, in fact, constitutes another additional circle of blood circulation. It performs the purification of blood plasma from harmful substances such as decay products and toxic components.
The portal vein system is formed by combining large trunks of veins near the liver. From the intestines, the superior mesenteric and inferior mesenteric veins carry blood. The splenic vessel leaves the organ of the same name and receives blood from the pancreas and stomach. These large veins, merging, become the basis of the crow's vein system.
Near the entrance to the liver, the vessel trunk, separating into branches (left and right), diverges between the lobes of the liver. In turn, the hepatic veins are divided into venules. A network of small veins covers all parts of the organ inside and out. After the contact of blood and soft tissue cells occurs, these veins will carry blood to the central vessels that exit from the middle of each lobe. After this, the central venous vessels are combined into larger ones, from which the hepatic veins are formed.
What is venous obstruction of the liver?
Hepatic vein thrombosis is called liver disease. It causes a violation of internal blood circulation and the formation of blood clots that block the outflow of blood from the organ. Official medicine also calls this Budd-Chiari syndrome.
Partial or complete narrowing of the gaps of the blood vessels resulting from a thrombus is characteristic of hepatic vein thrombosis. Most often it occurs in those places where the mouth of the vessels of the liver is located and they flow into the vena cava.
If there are any obstacles to the outflow of blood in the liver, the pressure in the blood vessels rises and the hepatic veins expand. Although the vessels are very elastic, too high a pressure can lead to rupture, resulting in internal bleeding with a possible fatal outcome.
The question of the origin of hepatic vein thrombosis has not been closed so far. Experts in this matter were divided into two camps. Some consider liver vein thrombosis to be an independent disease, while others claim that it is a secondary pathological process caused by a complication of the underlying disease.
The first case is thrombosis, which arose for the first time, that is, we are talking about the disease of Badda-Chiari. The second case includes Budd-Chiari syndrome, which manifested itself due to a complication of the primary disease, which is considered the main one.
Due to the complexity in the division of measures for the diagnosis of these processes, it is customary to call the blood circulation disorders of the liver not a disease, but a syndrome.
Causes of hepatic vein thrombosis
Blood clots in the liver occur due to:
- Protein S or C. Deficiency
- Antiphospholipid syndrome.
- Changes in the body associated with pregnancy.
- Long-term use of oral contraceptives.
- Inflammatory processes occurring in the intestines.
- Connective tissue diseases.
- Various peritoneal injuries.
- The presence of infections - amoebiasis, hydatid cysts, syphilis, tuberculosis, etc.
- Tumor invasion of the veins of the liver - carcinoma or renal cell carcinoma.
- Hematologic diseases - polycythemia, paroxysmal nocturnal hemoglobinuria.
- Hereditary predisposition and congenital malformations of the hepatic veins.
The development of Budd-Chiari syndrome usually lasts from a few weeks to months. Against this background, cirrhosis and portal hypertension often develop.
Symptoms
In the event that unilateral hepatic obstruction has developed, no special symptoms are observed. The manifestation of signs directly depends on the stage of development of the disease, the place where the thrombus formed, and the complications that arose.
Often, Budd-Chiari syndrome is characterized by a chronic form, which is not accompanied by symptoms for a long time. Sometimes signs of hepatic thrombosis can be detected by palpation. The disease itself is diagnosed solely as a result of an instrumental study.
Chronic blockage is characterized by symptoms such as:
- Light pain in the right hypochondrium.
- Sensation of nausea, sometimes accompanied by vomiting.
- Change in skin color - yellowing is manifested.
- Sclera of the eyes turn yellow.
The presence of jaundice is not necessary. In some patients, it may be absent.
Symptoms of acute blockage are more pronounced. These include:
- Suddenly begun vomiting, in which blood gradually begins to appear as a result of a rupture in the esophagus.
- Severe pains that are epigastric in nature.
- A progressive accumulation of free fluids in the peritoneal cavity, which occurs due to venous stasis.
- Acute pain throughout the abdomen.
- Diarrhea.
In addition to these symptoms, the disease accompanies an enlargement of the spleen and liver. For acute and subacute forms of the disease, liver failure is characteristic. There is also a fulminant form of thrombosis. It is extremely rare and dangerous in that all the symptoms develop very quickly, leading to irreparable consequences.
Diagnosis of blockage of the liver vessels
For Budd-Chiari syndrome, a clear clinical picture is characteristic. This greatly facilitates the diagnosis. If the patient has an enlarged liver and spleen, there are signs of fluids in the peritoneal cavity, and laboratory tests indicate overestimated blood coagulation, first of all, the doctor begins to suspect the development of thrombosis. However, he must carefully study the patient's history.
Significant reasons to suspect a patient with thrombosis include the following symptoms:
- heart failure;
- the presence of metastases in the liver;
- the presence of granulomatosis;
- the development of cirrhosis in newborns;
- peritonitis;
- diseases of an infectious origin (tuberculosis, syphilis, etc.);
- alcohol addiction.
In addition to the fact that the doctor studies the medical history and conducts a physical examination, the patient must donate blood for general and biochemical analysis, as well as for coagulation. It is still necessary to pass a liver test.
For the accuracy of diagnosis, the following examination methods are used:
- ultrasound examination;
- portal vein radiography;
- contrast study of blood vessels;
- computed tomography (CT);
- magnetic resonance imaging (MRI).
All these studies make it possible to assess the degree of enlargement of the liver and spleen, the severity of vascular damage, and to locate the thrombus.
Complications
If the patient comes to the doctor late or the diagnosis of changes resulting from thrombosis is late, the risk of complications increases. These include:
- liver failure;
- portal hypertension;
- hepatocellular carcinoma;
- ascites;
- encephalopathy;
- dilated hepatic vein bleeding;
- porosystemic collateralia;
- mesenteric thrombosis;
- liver necrosis ;
- bacterial peritonitis;
- fibrosis of the liver.
Treatment
In medical practice, two methods of treating Budd-Chiari syndrome are used. One of them is medication, and the second - with the help of surgical intervention. The disadvantage of drugs is that it is impossible to recover completely with their help. They give only a short-term effect. Even in case of timely treatment of the patient to the doctor and treatment with drugs, without the intervention of the surgeon, almost 90% of patients die within a short period of time.
The main goal of therapy is to eliminate the main causes of the disease and, as a result, restore blood circulation in the area of thrombosis.
Drug therapy
In order to remove excess fluid from the body, doctors prescribe drugs with a diuretic effect. To prevent the further development of thrombosis, anticoagulants are prescribed to the patient. Corticosteroids are used to relieve abdominal pain.
In order to improve blood characteristics and accelerate the resolution of blood clots formed fibrinolytics and antiplatelet agents are used. In parallel, supportive therapy is carried out aimed at improving metabolism in the liver cells.
Surgical therapy
Conservative treatment methods for the diagnosis associated with thrombosis cannot provide the necessary result - the restoration of normal circulation in the affected area. In this case, only radical methods will help.
If you have Budd-Chiari syndrome, one of the following treatment methods is recommended:
- Establish anastomoses (artificial synthetic messages between the vessels that allow you to restore blood circulation).
- Place a prosthesis or expand the vein mechanically.
- Install a shunt to lower blood pressure in the portal vein.
- Transplant the liver.
In the case of the fulminant course of the disease, practically nothing can be done. All changes occur very quickly, and doctors simply do not have time to take the necessary measures.
Prevention
All measures to prevent the development of Budd-Chiari syndrome are reduced to the fact that you need to regularly contact medical institutions in order to undergo, as a preventive measure, the necessary diagnostic procedures. This will help to timely detect and begin treatment of liver vein thrombosis.
There are no specific preventive measures of thrombosis. There are only measures to prevent relapse of the disease. These include taking blood thinning anticoagulants and undergoing examinations every 6 months after surgery.