The liver is a vital human external secretion gland. Its main functions include the neutralization of toxins and their removal from the body. In case of liver damage, this function is not performed and harmful substances enter the bloodstream. With the blood flow, 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 that there is any disease in the body for a long time. In this case, the patient goes to the doctor too late, and then the treatment no longer makes sense. Therefore, it is necessary to carefully monitor your lifestyle and regularly undergo preventive examinations.
Anatomy of the liver
According to the classification, the liver is divided into independent segments. Each is connected to a vascular inflow, outflow, and bile duct. In the liver, the portal vein, hepatic artery and bile duct divide into branches, which in each of its segments are collected into veins.
The venous system of the body is made up of adductor andblood vessels. The main adducting vein functioning in the liver is the portal vein. The hepatic veins belong to the outlets. 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.
Portal
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 portal vein is 6-8 cm long and 1.5 cm in diameter.
This blood vessel originates behind the head of the pancreas. Three veins merge there: the inferior mesenteric vein, the superior mesenteric vein, and the splenic vein. They make up the roots of the portal vein.
In the liver, the portal vein divides into branches, diverging in all hepatic segments. They accompany branches of the hepatic artery.
The blood that is carried by the portal vein saturates the organ with oxygen, delivers vitamins and minerals to it. This vessel plays an important role in digestion and detoxifies the blood. In case of malfunction of the portal vein, serious pathologies occur.
Hepatic vein diameter
The largest of the vessels of the liver is the right vein, the diameter of whichis 1.5-2.5 cm. Its confluence into the lower hollow occurs in the region of its front wall near the hole in the diaphragm.
Normally, the hepatic vein, formed by the left branch of the portal vein, empties at the same level as the right one, only on the left side. Its diameter is 0.5-1 cm.
The diameter of the vein of the caudate lobe in a he althy person is 0.3-0.4 cm. Its mouth is slightly below the place where the left vein flows into the inferior vena cava.
As you can see, the sizes of the hepatic veins differ from each other.
The right and left passing through the liver collect blood respectively from the right and left hepatic lobes. The middle and vein of the caudate lobe are from the lobes of the same name.
Hemodynamics in the portal vein
According to the course of anatomy, arteries pass through many organs of the human body. Their function is to saturate the organs with the substances they need. Arteries bring blood to organs and veins carry it out. 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 gate system functions in a specific way. The reason for this is its complex structure. From the main trunk of the portal vein, many branches branch off into venules and other channels of blood flow. That is why the portal system, in fact, is another additional circle of blood circulation. It cleans the blood plasma from harmful substances such as decay products and toxic components.
The portal vein system is formed as a result of the union of large trunks of veins near the liver. From the intestinesBlood is carried by the superior mesenteric and inferior mesenteric veins. The splenic vessel leaves the organ of the same name and receives blood from the pancreas and stomach. It is these large veins that, merging, become the basis of the crow vein system.
Near the entrance to the liver, the trunk of the vessel, dividing 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 the lobes 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 unite into larger ones, from which the hepatic veins are formed.
What is venous blockage of the liver?
Hepatic vein thrombosis is a pathology of the liver. It causes a violation of the internal circulation and the formation of blood clots that block the outflow of blood from the organ. Official medicine also calls it the Budd-Chiari syndrome.
Hepatic vein thrombosis is characterized by partial or complete narrowing of the lumen of blood vessels resulting from the action of a blood clot. 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 obstructions 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 much pressure can cause them to rupture, resulting inbecomes internal bleeding with a possible fatal outcome.
The question of the origin of hepatic vein thrombosis has not been closed so far. Experts on this issue are divided into two camps. Some consider hepatic vein thrombosis an independent disease, while others argue that it is a secondary pathological process caused as a result of a complication of the underlying disease.
The first case includes thrombosis, which occurred for the first time, that is, we are talking about Budd-Chiari disease. 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 difficulty in separating the measures for diagnosing these processes, it is customary for the medical community to call circulatory disorders of the liver not a disease, but a syndrome.
Causes of hepatic vein thrombosis
Clots in the blood vessels of the liver occur due to:
- Deficiency in protein S or C.
- Antiphospholipid syndrome.
- Changes in the body associated with pregnancy.
- Long-term use of oral contraceptives.
- Inflammatory processes taking place in the intestines.
- Connective tissue diseases.
- Various injuries of the peritoneum.
- Presence of infections - amoebiasis, hydatid cysts, syphilis, tuberculosis, etc.
- Tumor invasions of the veins of the liver - carcinoma or renal cell carcinoma.
- Hematological diseases - polycythemia, paroxysmal nocturnal hemoglobinuria.
- Hereditary predisposition and congenital defects of the hepatic veins.
Development of Budd-Chiari syndrome usually lasts from several weeks to months. Against its background, cirrhosis and portal hypertension often develop.
Symptoms
If unilateral hepatic obstruction has developed, there are no special symptoms. The manifestation of symptoms directly depends on the stage of development of the disease, the place where the thrombus formed, and the complications that have arisen.
Budd-Chiari syndrome is often 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:
- Slight pain in the right hypochondrium.
- Feeling nauseated, sometimes accompanied by vomiting.
- Change in the color of the skin - yellowing appears.
- The sclera of the eyes turn yellow.
The presence of jaundice is not necessary. Some patients may not have it.
Symptoms of acute blockage are more pronounced. These include:
- Sudden onset vomiting, which gradually begins to bleed as a result of a tear in the esophagus.
- Severe epigastric pain.
- Progressive accumulation of free fluids in the peritoneal cavity due to venous stasis.
- Sharp pain all over my stomach.
- Diarrhea.
In addition to these symptoms, the disease accompanies an increasespleen and liver. For the 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 because all the symptoms develop very quickly, leading to irreparable consequences.
Diagnosis of obstruction of hepatic vessels
Budd-Chiari syndrome is characterized by a clear clinical picture. 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 increased blood clotting, first of all, the doctor begins to suspect the development of thrombosis. However, he must take the patient's history very carefully.
Strong reasons to suspect thrombosis in a patient include the following signs:
- heart failure;
- presence of liver metastases;
- presence of granulomatosis;
- development of cirrhosis in newborns;
- peritonitis;
- diseases of 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 needs to donate blood for general and biochemical analysis, as well as for clotting. Still need to take a liver test.
For the accuracy of the diagnosis, the following examination methods are used:
- sound examination;
- portal vein x-ray;
- 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, to detect the location of the blood clot.
Complications
When a patient visits a doctor late or diagnoses changes resulting from thrombosis, the risk of complications increases. These include:
- liver failure;
- portal hypertension;
- hepatocellular carcinoma;
- ascites;
- encephalopathy;
- bleeding from an enlarged hepatic vein;
- porosystemic collatery;
- mesenteric thrombosis;
- liver necrosis;
- peritonitis, which is bacterial in nature;
- liver fibrosis.
Treatment
In medical practice, two methods of treating Budd-Chiari syndrome are used. One of them is medical, and the second - with the help of surgical intervention. The disadvantage of drugs is that it is impossible to cure completely with their help. They give only a short-term effect. Even in the case of a timely visit to a doctor and treatment with drugs, almost 90% of patients die within a short period of time without the intervention of a surgeon.
The main goal of therapy is to eliminate the main causes of the disease and, as a result, restore blood circulation in the area affected by thrombosis.
Drug therapy
In order to remove excess fluid from the body, doctors prescribe drugs with a diuretic effect. To prevent further development of thrombosis, the patient is prescribed anticoagulants. Corticosteroids are used to relieve abdominal pain.
Fibrinolytics and antiaggregants are used to improve blood characteristics and accelerate the resorption of formed blood clots. In parallel, supportive therapy is carried out aimed at improving metabolism in liver cells.
Surgical Therapy
Conservative methods of treatment with a diagnosis associated with thrombosis cannot provide the desired result - the restoration of normal circulation in the affected area. In this case, only radical methods will help.
If Budd-Chiari syndrome is present, one of the following treatments is recommended:
- Establish anastomoses (artificial synthetic messages between vessels that allow blood circulation to be restored).
- Put a prosthesis or mechanically dilate a vein.
- Install a shunt to lower blood pressure in the portal vein.
- Liver transplant.
In the case of a lightning-fast course of the disease, there is practically nothing that can be done. All changes are happening 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 forin order to undergo, as a preventive measure, the necessary diagnostic procedures. This will help to detect and start treatment of hepatic vein thrombosis in a timely manner.
There are no special preventive measures for thrombosis. There are only measures to prevent recurrence of the disease. These include taking blood-thinning anticoagulants and having checkups every 6 months after surgery.
