Home Pulpitis Portal vein drainage area. Anatomy of the Human Portal Vein - information

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Portal vein drainage area. Anatomy of the Human Portal Vein - information

The hepatic portal vein is a large visceral vessel that occupies a special place in the system of veins that collect blood from unpaired internal organs. Its length ranges from 5 to 6 cm, and its diameter ranges from 11 to 18 mm. The vessel is the afferent venous link of the portal system of the organ. In other words, the portal vein serves as the gateway for the entry of all blood leaving the stomach, spleen, pancreas, and intestines, with the exception of its lower third. The visceral trunk is formed by the fusion of three venous vessels, which are its main tributaries:

breeches;
lower breech;
splenic

In rare cases, the portal vein is formed as a result of the connection of only two of the listed vessels - the splenic and superior mesenteric. With this structure, the inferior mesenteric vein continues into the splenic vein.

Location

The portal vein of the liver is located in the thickness of the organ, namely in the hepatoduodenal ligament.

It is located behind the hepatic artery and bile duct. Entering the liver, the vessel is divided into two branches - the right (larger) and the left, which in turn branch into segmental ones, breaking up into many small ones and turning into interlobular veins. Sinusoidal vessels - wide capillaries flowing into a large central vein - extend into the lobules from them.

Through the portal trunk, blood from the unpaired abdominal organs enters the liver, and then follows into the inferior pudendal vein through the hepatic venous vessels.

Before the portal vein enters the liver, it drains right and leftgastric, prepyloric, cystic and peri-umbilical veins.

Vessel tributaries and their functions

As mentioned above, the portal vein of the liver has three main tributaries, which form it through their fusion.

The first one is superior mesenteric venous vessel , passes at the base of the small intestine with right side from the artery of the same name. The venous channels of the ileum and jejunum, as well as pancreatic, right and middle colon, pancreaticoduodenal, right gastroepiploic and ileocolic veins. A tributary of the portal trunk of the liver is also a vein vermiform appendix. All the described vessels carry blood to the superior mesenteric vein from the unpaired organs of the peritoneum (greater omentum, pancreas, duodenum, jejunum, ileum and colon), from where it goes directly to the liver.

The second main tributary of the portal canal is splenic vein, which runs parallel to the upper edge of the pancreas, located below the splenic artery and crossing the aorta in front. Its confluence with the superior mesenteric vein occurs behind the pancreas. The short gastric and pancreatic veins, as well as the left gastroepiploic vein, flow into the splenic venous canal. They carry blood from part of the stomach, spleen, greater omentum and pancreas.

The third major tributary of the hepatic portal vein is inferior mesenteric vein. It is formed due to the fusion of the sigmoid veins with the superior rectal and left colon. Passing under the pancreas, the vessel flows into the splenic vein.

The inferior mesenteric vein receives blood from the descending and sigmoid colons, as well as the walls of the stomach (its upper part). Sometimes it may continue into the superior mesenteric vein rather than the splenic vein. In this case, the hepatic portal vein is formed by only two tributaries.

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Portal vein, vena portae hepatis. Collects blood from the digestive system, abdominal cavity and spleen. Its tributaries form anastomoses with the rectal plexus, with the esophageal and superficial veins of the abdomen. Rice. A.
Right branch, ramus dexter. A thick and short trunk that divides inside the right lobe of the liver to the interlobular veins. Rice. A.
Anterior branch, ramus anterior. It goes to the anterior part of the right lobe of the liver. Rice. A.
Posterior branch, ramus posterior. Distributes to the posterior part of the right lobe of the liver. Rice. A.
Left branch, ramus sinister. A smaller caliber, but more extended branch of the portal vein, branching in the caudate, quadrate and left lobes of the liver. Rice. A.
Transverse part, pars transversa. The initial segment of the left branch, which is located transversely at the porta hepatis. Rice. A.
Tail branches, rami caudati. Rice. A.
Umbilical part, pars umbilicalis. Continuation of the left branch inside the lobus hepatis sinister in the sagittal direction. Rice. A.

[Ductus venosus, ductus venosus]. A vessel that in embryogenesis connects the left umbilical vein with the inferior vena cava, bypassing the liver. Rice. B.
Venous ligament, lig. venosum. A strand of connective tissue at the site of the ductus venosus in the groove of the same name. Rice. B.
Lateral branches, rami laterales. They are directed to the quadrate and part of the caudate lobes of the liver.
Left umbilical vein, v. umbilicalis sinistra. The embryonic vessel, which flows into the portal vein, and also through the ductus venosus connects to the inferior vena cava. Rice. B.
Round hepatic ligament, lig. teres hepatis. A fibrous cord that replaces the umbilical vein after birth. Rice. A.
Medial branches, rami mediales. They extend from the pars umbilicalis to the anterior part of the left lobe of the liver. Rice. A.
Gallbladder vein, v. cystica. It goes from the gallbladder to the right branch of the portal vein. Rice. A.
Periumbilical veins, vv. paraumbilicales. Surrounds the round ligament of the liver. Connect left branch portal vein and saphenous veins belly. Rice. A.
Left gastric vein, v. gastrica sinistra. Accompanies the artery of the same name. Rice. A.
Right gastric vein, v. gastrica dextra. It goes along with the artery of the same name. Rice. A.
Prepyloric vein, v. praepylorica. Branch from the anterior surface of the pylorus to the right gastric or portal veins. Rice. A.
Superior mesenteric vein, v. mesenterica superior. Collects blood from the walls of the intestinal tube, starting from distal section duodenum to the left bend colon. Connecting with v. splenica, forms the portal vein. Rice. A.

Jejunal veins, vv. jejunales. Blood is collected from the walls of the jejunum. Rice. A.
21a. Ileal veins, vv. ileales. Blood is collected from the walls of the ileum. Rice. A.
Right gastroepiploic vein, v. gastro-omentalis (epiploica) dextra. Accompanies the artery of the same name. Rice. A.
Pancreatic veins, vv. pancreaticae. They arise from the pancreas. Rice. A.
Pancreatoduodenal veins, w. pancreaticoduodenales. They are accompanied by arteries of the same name. Rice. A.
Ileocolic vein, v. ileocolica. Collects blood from the ileocecal area. Rice. A.
Vein of the appendix, v. appendicularis. Carries out the outflow of blood from the appendix. Rice. A.
Right colic vein, v. Colica dextra. It starts from the wall of the ascending colon. Rice. A.
Middle colic vein, v. Colica media (intermedia). Collects blood from the transverse colon. May open into the inferior mesenteric vein. Rice. A.
Splenic vein, v. splenica It passes first inside the splenorenal ligament, then behind the pancreas and connecting with v. mesenterica inferior, forms the portal vein. Rice. A.
Pancreatic veins, vv, pancreaticae. They open into the splenic vein. Rice. A.

Short gastric veins, vv. gastricae breves. They pass inside the gastrosplenic ligament. Rice. A.
Left gastroepiploic vein, v. gastroomentalis (epiploica) sinistra. Accompanies the artery of the same name. Rice. A.
Inferior mesenteric vein, v. mesenterica inferior. Collects blood from the walls of the intestinal tube, starting from the left bend of the colon to the upper part of the rectum and flows into the splenic vein. Rice. A.
Left colic vein, v. Colica sinistra. Collects blood from the descending colon. Rice. A.
Sigmoid veins, vv. sigmoideae. Blood is collected from the sigmoid colon. Rice. A.
Superior rectal vein, v. rectalis superior. It arises from the upper part of the rectum. Rice. A.
Common iliac vein, v. iliac communis. It is located along the length from L 4 to the sacroiliac joint. It connects with the vessel of the same name on the opposite side and forms the inferior vena cava. Rice. A.
Median sacral vein, v. sacralis mediana. Unpaired tributary of the left common iliac vein. Rice. A.
Iliopsoas vein, v. iliolumbalis. Accompanies the artery of the same name and opens into the common or internal iliac vein. Rice. A.

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Portal vein. v. portae , collects blood from unpaired abdominal organs. It is formed behind the head of the pancreas by the fusion of three veins: the inferior mesenteric vein, v.
sen-terica inferior, superior mesenteric vein, v. mesenterica superior, and splenic vein, v. lienalis. The portal vein from the place of its formation goes up and to the right, passes behind the upper part of the duodenum and enters the hepatoduodenal ligament, between the layers of which it reaches the portal of the liver. In the thickness of this ligament, the portal vein is located together with the common bile duct and the common hepatic artery in such a way that the duct occupies the extreme position on the right, to the left of it is the common hepatic artery, and deeper and between them is the portal vein. U Porta hepatis v. portae is divided into two branches: the left branch, ramus sinister, and the right branch, ramus dexter, respectively, the right and left lobes of the liver. The right branch of the portal vein is wider than the left; it enters through the portal of the liver into the thickness of the right lobe of the liver, where it divides into the anterior and posterior branch, rr. anterior et posterior. The left branch is longer than the right; heading to the left side of the portal of the liver, it gives along the way a transverse branch, g. transversus. branches to the caudate lobe, caudal branches, rr. caudati, lateral and medial branches, rr. laterales et mediates, into the parenchyma of the left lobe of the liver. Three veins: inferior mesenteric vein, v. mesenterica inferior, superior mesenteric vein, v. mesenterica superior, and splenic vein, v. lienalis, from which v. is formed. portae, are called the roots of the portal vein; the portal vein receives the left and right gastric veins, vv. gastricae sinistra et dextra. prepyloric vein, v. prepylorica, pancreatic veins, vv. pancreaticae.

Inferior mesenteric vein, v. mesenterica inferior, collects blood from the walls of the upper part of the rectum, sigmoid colon and descending colon and with its branches corresponds to all the branches of the inferior mesenteric artery. It begins in the cavity of the small pelviscalled the superior rectal vein, v. rectalis superior, which in the wall of the rectum is connected with its branches to the rectal venous plexus, plexus venosus rectalis. The superior rectal vein runs upward, crosses the anterior iliac vessels, vasa iliaca, at the level of the left sacroiliac joint and receives the sigmoid veins, vv. sigmoideae, which follow from the wall of the sigmoid colon. The inferior mesenteric vein is located retroperitoneally and, heading upward, forms a small arc with its convexity facing to the left. Taking the left colic vein, v. colica smistra, the inferior mesenteric vein deviates to the right, passes immediately to the left of the flexura duodenojejunalis under the pancreas and most often connects with the splenic vein. Sometimes the inferior mesenteric vein drains directly into the portal vein.

Superior mesenteric vein. v. mesenterica superior, collects blood from the small intestine and its mesentery, the appendix and cecum, the ascending and transverse colon and from the mesenteric lymph nodes of these areas. The trunk of the superior mesenteric vein is located to the right of the artery of the same name and with its branches accompanies all the branches of the artery. The superior mesenteric vein begins in the region of the ileocecal angle, where it is called the ileocolic vein. Ileocolic vein, v. ileocolica, collects blood from the terminal ileum, appendix and cecum. Heading up and to the left, the ileocolic vein directly continues into the superior mesenteric vein. The superior mesenteric vein is located at the root of the mesentery of the small intestine and, forming an arch with a convexity to the left and down, receives a number of veins.

a) Veins of the jejunum and ileum, vv. jejunales et ilei, numbering 16-20, come from the mesentery of the small intestine, where with their branches they accompany the branches of aa.. intestinales. The intestinal veins join the superior mesenteric vein on the left.

b) Right colic veins, vs. colicae dextrae, go retroperitoneally from the ascending colon and anastomose with the ileocolic and middle colon veins.

c) Middle colic vein, v. colica media, located between the layers of the mesentery of the transverse colon; it collects blood from the flexura hepatica and colon transversum. The middle colic vein in the area of flexura coli sinistra anastomoses with the left colic vein, v. colica sinistra, forming a large arcade with it.

d) Right gastroepiploic vein, v. gastroepiploica dextra, accompanies the artery of the same name along the greater curvature of the stomach; blood flows into it from the stomach through the gastric veins, vv. gastricae, and from the greater omentum along the omental veins, vv. epiploicae; at the level of the pylorus it flows into the superior mesenteric vein. Before entering, it receives the pancreatic and pancreaticoduodenal veins, vv. pancreaticoduodenal s that collect blood from the duodenum and pancreas.

Splenic vein, v. Uenalis, collects blood from the spleen, stomach, pancreas and greater omentum. It is formed in the area of the hilum of the spleen from numerous w. lienales emerging from the substance of the spleen. Here the splenic vein receives: the left gastroepiploic vein, v. gastroepiploica sinistra, which accompanies the artery of the same name and collects blood from the stomach, greater omentum, and short gastric veins, vv. gastricae breves, - from the area of the fundus of the stomach. From the hilum of the spleen, the splenic vein runs to the right along top edge pancreas, located below the artery of the same name. It crosses the anterior surface of the aorta immediately above the superior mesenteric artery and merges with the superior mesenteric vein to form the portal vein. The splenic vein receives the pancreatic veins, vv. rap-creaticae, and in the area of the head of the gland - the duodenal vein. In addition to the indicated veins that form the portal vein, the following veins flow directly into its trunk.

a) Pancreatoduodenal veins - from the head of the pancreas and duodenum.

b) Pancreatic veins.

c) Prepyloric vein, v. prepylorica, begins in the pyloric region of the stomach and accompanies the right gastric artery.

d) Gastric veins, left and right, v. gastrica sinistra et v. gastrica dextra, run along the lesser curvature of the stomach and accompany the gastric arteries.

In the area of the pylorus, the pyloric veins flow into them, in the area of the cardial part of the stomach - veins esophagus. Directly in the substance of the liver, the portal vein receives one large and a number of small veins; cystic vein, v. cystica, veins from the walls of the portal vein itself, hepatic arteries and liver ducts, as well as veins from the diaphragm, which are lig. suspensorium reach the liver. The portal vein connects with the veins of the anterior abdominal wall through the periumbilical veins. Periumbilical veins, vv. paraumbilicales, begin in the anterior abdominal wall around the navel, where they anastomose with the branches of the superficial and deep superior and inferior epigastric veins. Heading to the liver along the round ligament of the liver, the peri-umbilical veins either unite into one trunk or flow into the portal vein in several branches.

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PORTAL VEIN SYSTEM

Portal vein (liver)(v. portae hepatis)- the largest visceral vein, 5-6 cm long, 11-18 mm in diameter, the main vessel of the so-called portal system of the liver. The portal vein of the liver is located in the thickness of the hepatoduodenal ligament behind the hepatic artery and the common bile duct along with the nerves, lymph nodes and vessels. The portal vein is formed from the veins of unpaired abdominal organs: the stomach, small and large intestines (except the anus), spleen and pancreas. From these organs, venous blood flows through the portal vein into the liver, and from it through the hepatic veins into the inferior vena cava. The main tributaries of the portal vein are the superior mesenteric, splenic and inferior mesenteric veins, which merge with each other behind the head of the pancreas (Fig. 171, Table 29). Having entered the portal of the liver, the portal vein divides into a larger one right branch(r. dexter) And left branch(r. sinister). Each of these branches breaks up first into segmental ones, and then into branches of ever smaller diameter, which pass into interlobular veins. From them, sinusoidal vessels extend into the lobules and flow into the central vein of the lobule. From each lobule comes sublobular vein, which, merging, form 3-4 hepatic veins(vv. hepaticae). Thus, the blood flowing into the inferior vena cava through the hepatic veins passes on its way through two capillary networks: located in the walls of the digestive tract, where the tributaries of the portal vein originate, and formed in the liver parenchyma from the capillaries of its lobules.

In the thickness of the hepatoduodenal ligament, the portal vein flows gallbladder vein(v. cystica), right And left gastric vein (vv. gastricae dextra et sinistra) And prepyloric vein(v. prepylorica). The left gastric vein anastomoses with the esophageal veins - tributaries of the azygos vein from the superior vena cava system. In the thickness of the round ligament of the liver, they approach this organ paraumbilical veins (vv. paraumbilicales), which begin in the navel area, where they anastomose with the upper

Rice. 171. Diagram of the portal vein and its tributaries, front view: 1 - esophageal veins; 2 - left gastric vein; 3 - stomach; 4 - spleen; 5 - left gastroepiploic vein; 6 - splenic vein; 7 — inferior mesenteric vein; 8 - left colic vein; 9 - left common iliac vein; 10 - superior rectal vein; 11 - right common iliac vein; 12 - inferior vena cava; 13 - right colic vein; 14 — middle colonic vein; 15 - superior mesenteric vein; 16 — right gastroepiploic vein; 17 - duodenum; 18 - right gastric vein; 19 - portal vein of the liver; 20 - liver; 21 - right branch of the portal vein of the liver; 22 - left branch of the portal vein of the liver

Table 29. Portal vein system

epigastric veins - tributaries of the internal thoracic veins (from the superior vena cava system) and with superficial And inferior epigastric veins (vv. epigastricae superficiales et inferior)- tributaries of the femoral and external iliac veins from the inferior vena cava system.

Tributaries of the portal vein. Superior mesenteric vein(v. mesenterica superior) passes at the root of the mesentery of the small intestine to the right of the artery of the same name. Its tributaries are skinny veins And ileum (vv. jejunales et iledles), pancreatic veins (vv. pancredticae), pancreaticoduodenal veins (vv. pancreaticoduodenales), ileocolic vein(v. ileo-colica), right gastroepiploic vein(v. gastroepipldica dextra), right And middle colon veins (vv. colicae media et dextra), vein of the appendix(v. appendicularis), through which blood flows into the superior mesenteric vein from the walls of the jejunum and ileum, the appendix, the ascending, transverse colon, partly from the stomach, duodenum and pancreas, and the greater omentum.

Splenic vein(v. liendlis) runs along the upper edge of the pancreas below the splenic artery from left to right, crossing the aorta in front. Posterior to the head of the pancreas, the splenic vein joins the superior mesenteric vein. The tributaries of the splenic vein are pancreatic veins (vv. pancredaticae), short gastric veins(vv. gdstricae brdves) And left gastroepiploic vein(v. gastroepipldica sinistra). The latter anastomoses along the greater curvature of the stomach with the right vein of the same name. The splenic vein collects blood from the spleen, part of the stomach, pancreas and greater omentum.

Inferior mesenteric vein(v. mesenterica inferior) formed as a result of the merger superior rectal vein (v. rectalis superior), left colic vein (v. colica sinistra) And sigmoid veins (vv. sigmoideae). The inferior mesenteric vein runs upward, located next to the left colic artery, passes behind the pancreas and flows into the splenic vein (sometimes into the superior mesenteric vein). The inferior mesenteric vein collects blood from the walls of the upper rectum, sigmoid colon, and descending colon.

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The portal vein (v. portae) collects blood from the unpaired organs of the abdominal cavity (stomach, small and large intestines, pancreas and spleen) and represents the largest vein of the internal organs (Fig. 425). The portal vein has the following tributaries.

1. The superior mesenteric vein (v. mesenterica superior) is single, located at the root of the mesentery of the small intestine, next to the superior mesenteric artery, collects blood from the small intestine (vv. jejunales et ilei), the appendix and the cecum (vv. ileocolicae), ascending colon (v. colica dextra), transverse colon (v. colica media), head of the pancreas and duodenum (vv. pancreaticoduodenales superior et inferior), greater curvature of the stomach and transverse colon (v. gastroepiploica dextra).
2. The splenic vein (v. lienalis) is single, collects blood from the spleen, fundus and body of the stomach along the greater curvature (v. gastroepiploica sinistra, vv. gastricae breves) and the pancreas (vv. pancreaticae). The splenic vein connects behind the head of the pancreas and the upper horizontal part of the duodenum with the superior mesenteric vein into the portal vein.
3. The inferior mesenteric vein (v. mesenterica inferior) collects blood from the descending colon (v. colica sinistra), sigmoid (vv. sigmoideae) and the upper part of the rectum (v. rectalis superior). The inferior mesenteric vein connects with the splenic vein in the middle of the body of the pancreas or flows into the corner of the junction of the superior mesenteric and splenic veins.
4. Directly connected to the portal vein are the cystic vein (v. cystica), paraumbilical veins (vv. paraumbilicales), located in the lig. teres hepatis, left and right gastric veins (vv. gastricae sinistra et dextra), prepyloric vein (v. prepylorica).

The portal vein from the place of formation (behind the head of the pancreas) from the gate of the liver has a length of 4-5 cm and a diameter of 15-20 mm. It lies in lig. hepatoduodenale, where the ductus choledochus passes to the right of it, and a. hepatica propria. At the porta hepatis, the portal vein divides into two large lobar branches, which in turn branch into 8 segmental veins. Segmental veins are divided into interlobular and septal veins, which end in sinusoids (capillaries) of the lobules. The capillaries are radially oriented between the hepatic beams towards the center of the lobule. In the center of the lobules, capillaries form central veins(vv. centrales), representing the initial vessels for the hepatic veins flowing into the inferior vena cava. Thus, venous blood from the internal organs of the abdominal cavity, before entering the inferior vena cava, passes through the liver, where it is cleared of toxic metabolic products.

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The portal vein (portal vein or PV) is a large vascular trunk that collects blood from the stomach, spleen, and intestines, and then transports it to the liver. There the blood is cleansed and again returns to the hematocirculatory channel.

The anatomy of the vessel is quite complex: the main trunk branches into venules and other blood vessels with different diameters. Thanks to the portal vein (PV), the liver is saturated with oxygen, vitamins, and minerals. This vessel is very important for normal digestion and blood detoxification. When explosives malfunction, severe pathologies appear.

As mentioned earlier, the hepatic portal vein has a complex structure. The portal system is a kind of additional circle of blood flow, the main task of which is to cleanse the plasma of toxins and decay products.

The portal system has a complex structure

In the absence of the portal vein system (PVS), harmful substances would immediately enter the inferior vena cava (IVC), the heart, the pulmonary circulation and the arterial part of the large circulation. A similar disorder occurs with diffuse changes and compaction of the liver parenchyma, which manifests itself, for example, in cirrhosis. Due to the fact that there is no “filter” on the path of venous blood, the likelihood of severe poisoning of the body with metabolites increases.

From the anatomy course we know that many organs contain arteries that saturate them useful substances. And veins come out of them, which transport blood after processing to the right side of the heart, the lungs.

The PS is structured a little differently - the so-called gates of the liver include an artery and a vein, the blood from which passes through the parenchyma and again enters the veins of the organ. That is, an auxiliary blood circulation is formed, which affects the functionality of the body.

The formation of SVV occurs due to large vein trunks that unite next to the liver. The mesenteric veins carry blood from the intestines, the splenic vessel leaves the organ of the same name and receives nutrient fluid (blood) from the stomach and pancreas. Behind the last organ, large veins merge, which give rise to the SVV.

Gastric, periumbilical, and prepyloric veins pass between the panecretoduodenal ligament and the PV. In this area, the PV is located behind the hepatic artery and the common bile duct, with which it follows to the porta hepatis.

Near the portal of the organ, the venous trunk is divided into the right and left branches of the venous veins, which pass between the hepatic lobes and branch into venules. Small veins cover the hepatic lobule externally and internally, and after blood contacts the liver cells (hepatocytes), they move to the central veins emerging from the middle of each lobule. The central venous vessels unite into larger ones, after which they form the hepatic veins, which drain into the IVC.

If the size of the PV changes, this may indicate cirrhosis, PV thrombosis, spleen diseases, and other pathologies. Normally, the length of the PV is from 6 to 8 cm, and the diameter is about 1.5 cm.

Portal vein basin

The portal system of the liver is not isolated from other systems. They pass side by side so that if blood circulation is impaired in this area, “excess” blood can be discharged into other venous vessels. Thus, the patient’s condition in case of severe pathologies of the liver parenchyma or venous thrombosis is temporarily compensated, but at the same time the likelihood of hemorrhages increases.

The PV is connected to the veins of the stomach, esophagus, intestines, etc.

The PV and other venous collectors are connected through anastomoses (connections). Their placement is well known to surgeons who often stop bleeding from anastomosing sites.

The connections of the portal and hollow venous vessels are not pronounced, since they do not bear any special load. When the functionality of the IV is disrupted, when the flow of blood to the liver is hampered, the portal vessel expands, the pressure in it increases, and as a result, blood is discharged into the anastomoses. That is, the blood that should have entered the PV fills the vena cava through the portacaval anastomoses (system of anastomoses).

The most significant PV anastomoses:

Connections between the veins of the stomach and esophagus.
Anastomosis between the venous vessels of the rectum.
Anastomoses of the veins of the anterior abdominal wall.
Vein connections digestive organs with vessels of the retroperitoneal space.

The most important is the venous junction between the stomach and esophagus. When blood flow in the PV is disrupted, it expands, pressure increases, and blood fills the veins of the stomach. The gastric veins have collaterals (bypass paths of blood flow) with the esophageal veins, where blood that does not reach the liver rushes.

As mentioned earlier, the ability to release blood into a hollow vessel through the esophageal vessels is limited, so they expand due to overload, increasing the likelihood of dangerous hemorrhage. The vessels of the lower and middle third of the esophagus do not collapse, as they are located longitudinally, but there is a risk of their damage during eating, vomiting, and reflux. Often, hemorrhage from the veins of the esophagus and stomach affected by varicose veins is observed in cirrhosis.

From the veins of the rectum, blood rushes into the PS and IVC. When the pressure in the IV pool increases, a stagnation process occurs in the vessels of the upper part of the liver, from where the fluid enters the middle vein of the lower part of the colon through collaterals. As a result, hemorrhoids appear.

The third place where the 2 venous pools merge is the anterior wall of the abdomen, where the vessels of the peri-umbilical zone receive “excess” blood, expanding closer to the periphery. This phenomenon is called "jellyfish head".

The connections between the veins of the retroperitoneum and the PV are not as pronounced as those described above. Identify them by external symptoms it won’t work, and they are not predisposed to hemorrhage.

IV thrombosis

Portal vein thrombosis (PVT) is a pathology characterized by slowing or blocking of blood flow in the PV by blood clots. Clots obstruct the movement of blood to the liver, resulting in hypertension in the vessels.

PVT provokes various diseases and medical procedures

Causes of hepatic portal vein thrombosis:

Cirrhosis.
Bowel cancer.
Inflammatory lesion of the umbilical vein during catheterization in an infant.
Inflammatory diseases of the digestive tract (inflammation of the gallbladder, intestines, ulcers, etc.).
Trauma, surgery (bypass surgery, splenectomy, cholecystectomy, liver transplantation).
Coagulation disorders (Vaquez disease, pancreatic tumor).
Some infectious diseases (tuberculosis of portal lymph nodes, cytomegalovirus infection).

Thrombosis is most rarely provoked by pregnancy, as well as oral contraceptives, which a woman has been taking for a long time. This is especially true for patients over 40 years of age.

With PVT, a person experiences discomfort, abdominal pain, nausea, vomiting, and stool disorders. In addition, there is a possibility of fever and rectal bleeding.

With progressive thrombosis (chronic), blood flow in the PV is partially preserved. Then they become more severe symptoms portal hypertension (PH):

fluid in the abdominal cavity;
enlarged spleen;
feeling of heaviness and pain on the left under the ribs;
dilatation of the veins of the esophagus, which increases the likelihood of dangerous hemorrhage.

If a patient is rapidly losing weight or suffers from excessive sweating (at night), then it is necessary to conduct a high-quality diagnosis. If he has an enlarged lymph node near the gate of the liver and the organ itself, then competent therapy cannot be avoided. This results in lymphadenopathy, which is a sign of cancer.

Ultrasound will help identify vein thrombosis; in the image, a thrombus in the portal vein looks like a formation with a high density for ultrasound waves. The blood clot fills the IV, as well as its branches. A Doppler ultrasound will show that there is no blood flow in the damaged area. Small veins dilate, as a result, cavernous degeneration of blood vessels is observed.

Endo-ultrasound, computed tomography or MRI can help identify small blood clots. In addition, with the help of these studies it is possible to identify the causes of thrombosis and its complications.

Portal hypertension (PH) is a condition that is manifested by increased pressure in the PS. The pathology often accompanies IV thrombus, severe systemic diseases(most often the liver).

With portal hypertension, the pressure in the PV increases

PG is detected when the circulation is blocked, causing the pressure in the SVV to increase. Blockage can occur at the level of the IV (prehepatic PG), in front of the sinusoidal capillaries (hepatic PG), in the inferior vena cava (suprahepatic PG).

In a healthy person, the pressure in the PV is about 10 mmHg. Art., if this value increases by 2 units, then this is a clear sign of PG. In this case, the anastomosis between the tributaries of the venous veins, as well as the tributaries of the superior and inferior vena cava, gradually turns on. Then varicose veins affect collaterals (bypass paths of blood flow).

Factors for the development of PG:

Cirrhosis.
Hepatic vein thrombosis.
Different types of hepatitis.
Congenital or acquired changes in the structures of the heart.
Metabolic disorders (for example, pigmentary cirrhosis).
Thrombosis of the splenic vein.
PV thrombosis.

PG is manifested by dyspepsia (flatulence, defecation disorders, nausea, etc.), heaviness on the right under the ribs, coloring of the skin, mucous membranes in yellow, weight loss, weakness. With increased pressure in the SVV, splenomegaly appears (enlarged spleen). This is due to the fact that the spleen suffers most from venous stagnation, since blood cannot leave the vein of the same name. In addition, ascites (fluid in the abdomen) appears, as well as varicose veins of the lower esophagus (after bypass surgery). Sometimes the patient has enlarged lymph nodes at the porta hepatis.

Using an ultrasound examination of the abdominal organs, changes can be detected in the spleen, as well as fluid in the abdomen. Doppler measurements will help assess the diameter of the vessel and the speed of blood movement. As a rule, with PG, the portal, superior mesenteric and splenic veins are enlarged.

Portal vein cavernoma

When a patient is diagnosed with cavernous transformation portal vein“Not everyone understands what this means. Cavernoma may be congenital defect development of hepatic veins or a consequence of liver disease. With portal hypertension or thrombosis of the PV near its trunk, many small vessels are sometimes found that intertwine and compensate for blood circulation in this area. Cavernoma looks like a neoplasm in appearance, which is why it is called that. When the formations are differentiated, it is important to begin treatment (surgery).

Cavernoma is vascular formation in the liver

In younger patients, cavernous transformation indicates congenital pathologies, and in adults – about portal hypertension, cirrhosis, hepatitis.

Pylephlebitis

A purulent inflammatory lesion of the portal vein and its branches is called pylephlebitis, which often develops into PVT. Often the disease provokes acute appendicitis, it ends with purulent-necrotic inflammation of the liver tissue and death.

Pylephlebitis is a purulent lesion of the IV

Pyephlebitis does not have characteristic symptoms, so it is quite difficult to identify it. Not so long ago, this diagnosis was given to patients after their death. Now, thanks to new technologies (MRI), the disease can be detected during life.

Purulent inflammation manifests itself as fever, chills, severe poisoning, and abdominal pain. Sometimes hemorrhage occurs from the veins of the esophagus or stomach. When the liver parenchyma becomes infected, purulent processes develop, which is manifested by jaundice.

After laboratory research it will become known that the erythrocyte sedimentation rate has increased, the concentration of leukocytes has increased, which indicates acute purulent inflammation. But a diagnosis of “pyophlebitis” can only be made after an ultrasound, CT, or MRI.

Diagnostic measures

Ultrasound is most often used to detect changes in the portal vein. This is a cheap, accessible, safe diagnostic method. The procedure is painless and suitable for patients of all ages.

VV pathologies are detected using ultrasound and MRI

Doppler ultrasound allows you to evaluate the nature of blood movement; the portal vein is visible at the gate of the liver, where it divides into 2 branches. Blood moves towards the liver. Using 3-D/4-D ultrasound, you can obtain a three-dimensional image of the vessel. The normal width of the ventricular lumen during ultrasound examination is about 13 mm. Vessel patency is of great importance in diagnosis.

This method also allows you to detect hypoechoic (reduced acoustic density) or hyperechoic (increased density) contents in the portal vein. Such foci indicate dangerous diseases(PVT, cirrhosis, abscess, carcinoma, liver cancer).

With portal hypertension, an ultrasound will show that the diameter of the vessels is increased (this also applies to the size of the liver), and fluid has accumulated in the abdominal cavity. With the help of color Doppler, it is possible to detect that blood circulation has slowed down and cavernous changes have appeared ( indirect symptom portal hypertension).

Magnetic resonance imaging is useful in that it helps determine the causes of changes in the portal vein system. The liver parenchyma, lymph nodes and surrounding formations are examined. MRI will show that normally the maximum vertical size of the right lobe of the liver is 15 cm, the left one is 5 cm, and the bilobar size at the porta hepatis is 21 cm. With deviations, these values change.

One of the most effective methods for diagnosing PVT is angiography. In case of PG, fibrogastroduodenoscopy, esophagoscopy, and X-rays using a contrast agent are required to examine the esophagus or stomach.

Except instrumental studies, laboratory tests are also carried out. With their help, deviations from the norm are detected (excess of leukocytes, increased liver enzymes, blood serum contains a large amount of bilirubin, etc.).

Treatment and prognosis

Treatment of portal vein pathologies requires a comprehensive drug therapy, surgical intervention. The patient is usually prescribed anticoagulants (Heparin, Pelentan), thrombolytic drugs (Streptokinase, Urokinase). The first type of medication is necessary to prevent thrombosis and restore vein patency, and the second destroys the blood clot itself, which blocks the lumen of the vein. To prevent portal vein thrombosis, non-selective β-blockers (Obzidan, Timolol) are used. These are the most effective medications for the treatment and prevention of PVT.

VV pathologies are treated with medications and surgical intervention

If medications are ineffective, the doctor prescribes transhepatic angioplasty or thrombolytic therapy with portosystemic shunting in the liver. The main complication of IV thrombosis is hemorrhage from the esophageal veins, as well as intestinal ischemia. These dangerous pathologies can only be treated surgically.

The prognosis for portal vein pathologies depends on the degree of damage that they provoked. If thrombolytic therapy in the treatment of acute thrombosis turned out to be not entirely effective, then surgery cannot be avoided. Chronic thrombosis can lead to dangerous complications, so the patient must first be given first aid. Otherwise, the risk of death increases.

Thus, the portal vein is an important vessel that collects blood from the stomach, spleen, pancreas, and intestines and transports it to the liver. After filtration, it returns to the venous bed. VV pathologies do not go away without leaving a trace and threaten dangerous complications, even death, so it is important to identify the disease in time and carry out competent therapy.

Portal vein(liver) occupies a special place among the veins that collect blood from the internal organs. This is not only the largest visceral vein (its length is 5-6 cm, diameter 11-18 mm), but it is also the afferent venous link of the so-called portal system of the liver. The portal vein of the liver is located in the thickness of the hepatoduodenal ligament behind the hepatic artery and the common bile duct along with nerves, lymph nodes and vessels. It is formed from the veins of unpaired abdominal organs: stomach, small and large intestines, except the anus, spleen, pancreas. From these organs, venous blood flows through the portal vein to the liver, and from it through the hepatic veins into the inferior vena cava. The main tributaries of the portal vein are the superior mesenteric and splenic veins, as well as the inferior mesenteric vein, which merge with each other behind the head of the pancreas. After entering the porta hepatis, the portal vein divides into a larger right branch and a left branch. Each of the branches, in turn, breaks up first into segmental ones, and then into branches of ever smaller diameter, which pass into interlobular veins. Inside the lobules they give off wide capillaries - the so-called sinusoidal vessels, flowing into the central vein. The sublobular veins emerging from each lobule merge to form 34 hepatic veins. Thus, the blood flowing into the inferior vena cava through the hepatic veins passes on its way through two capillary networks: located in the wall of the digestive tract, where the tributaries of the portal vein originate, and formed in the liver parenchyma from the capillaries of its lobules. Before entering the portal of the liver (in the thickness of the hepatoduodenal ligament), the gallbladder vein (from the gallbladder), the right and left gastric veins and the prepyloric vein flow into the portal vein, delivering blood from the corresponding parts of the stomach. The left gastric vein anastomoses with the esophageal veins - tributaries of the azygos vein from the superior vena cava system. In the thickness of the round ligament of the liver, the paraumbilical veins follow to the liver. They begin in the navel area, where they anastomose with the superior epigastric veins - tributaries of the internal thoracic veins (from the superior vena cava system) and with the superficial and inferior epigastric veins - tributaries of the femoral and external iliac veins from the inferior vena cava system.

Portal vein tributaries

Superior mesenteric vein goes at the root of the mesentery of the small intestine to the right of the artery of the same name. Its tributaries are the veins of the jejunum and ileum, pancreatic veins, pancreatoduodenal veins, ileocolic vein, right gastroepiploic vein, right and middle colic veins, vein of the appendix. To the superior mesenteric vein, the veins listed above bring blood from the walls of the jejunum and ileum and the appendix, the ascending colon and transverse colon, partly from the stomach, duodenum and pancreas, and the greater omentum.

Splenic vein, located along the upper edge of the pancreas below the splenic artery, passes from left to right, crossing the aorta in front, and behind the head of the pancreas merges with the superior mesenteric vein. Its tributaries are the pancreatic veins, short gastric veins and the left gastroepiploic vein. The latter anastomoses along the greater curvature of the stomach with the right vein of the same name. The splenic vein collects blood from the spleen, part of the stomach, pancreas and greater omentum.

Inferior mesenteric vein, is formed as a result of the confluence of the superior rectal vein, the left colic vein and the sigmoid veins. Located next to the left colic artery, the inferior mesenteric vein goes up, passes under the pancreas and flows into the splenic vein (sometimes into the superior mesenteric vein). This vein collects blood from the walls of the upper rectum, sigmoid colon, and descending colon.

The portal vein system includes all veins through which venous blood flows from the intra-abdominal part gastrointestinal tract, spleen, pancreas and gallbladder. At the porta hepatis, the portal vein divides into two main lobar branches for each lobe. It does not contain valves (Fig. 10-1) in the main branches.

Portal vein is formed from the confluence of the superior mesenteric and splenic veins behind the head of the pancreas approximately at the level of the second lumbar vertebra. Further, the vein is located slightly to the right of the midline; its length to the portal of the liver is 5.5-8 cm. In the liver, the portal vein is divided into segmental branches accompanying the branches of the hepatic artery.

Rice. 10-1. Anatomical structure of the portal vein system. The portal vein is located behind the pancreas. See also color illustration on p. 770.

Superior mesenteric vein is formed by the confluence of veins extending from the small and large intestines, from the head of the pancreas and sometimes from the stomach (right gastroepiploic vein).

Splenic veins (from 5 to 15) begin from the hilum of the spleen and, near the tail of the pancreas, merge with the short gastric veins, forming the main splenic vein. It runs horizontally along the body and head of the pancreas, located posterior and inferior to the splenic artery. Many small branches from the head of the pancreas flow into it, near the spleen - the left gastroepiploic vein, and in its medial third - inferior mesenteric vein, carrying blood from the left half of the colon and from the rectum. Sometimes the inferior mesenteric vein drains at the confluence of the superior mesenteric and splenic veins.

In men blood flow through the portal vein is about 1000-1200 ml/min.

After eating, the absorption of oxygen by the intestines increases and the difference between arterial and portal blood in oxygen content increases.

Blood flow in the portal vein. The distribution of portal blood flow in the liver is not constant: blood flow to the left or to the left may predominate. right lobe liver. In humans, it is possible for blood to flow from the system of one lobar branch to the system of another. Portal blood flow appears to be laminar rather than turbulent.

Portal vein pressure in humans it is normally about 7 mm Hg (Fig. 10-2).

Collateral circulation

When outflow through the portal vein is impaired, regardless of whether it is caused by intra- or extrahepatic obstruction, portal blood flows into the central veins through venous collaterals, which at the same time significantly expand (Fig. 10-3 and 10-28).

Rice. 10-2. Blood flow and pressure in the hepatic artery, portal and hepatic veins.

Intrahepatic obstruction (cirrhosis)

Normally, all portal blood can flow through the hepatic veins; in liver cirrhosis, only 13% leaks. The rest of the blood passes through collaterals, which can be combined into 4 main groups.

I group: collaterals passing in the area of transition of the protective epithelium into the absorbent one.

A. In the cardiac part of the stomach there are anastomoses between the left, posterior and short veins of the stomach, which belong to the portal vein system, and the intercostal, diaphragmatic-esophageal and hemizygos veins, which belong to the inferior vena cava system. Redistribution of flowing blood into these veins leads to varicose veins of the submucosal layer of the lower esophagus and the fundus of the stomach.

B. In the anal area, there are anastomoses between the superior hemorrhoidal vein, which belongs to the portal vein system, and the middle and inferior hemorrhoidal veins, which belong to the inferior vena cava system. Redistribution of venous blood into these veins leads to varicose veins of the rectum.

II group: veins running in the falciform ligament and associated with the peri-umbilical veins, which are a rudiment of the fetal umbilical circulatory system (Fig. 10-4).

III group: collaterals passing in the ligaments or folds of the peritoneum, formed during its transition from the abdominal organs to the abdominal wall or retroperitoneal tissue. These collaterals run from the liver to the diaphragm, in the splenorenal ligament and in the omentum. These also include lumbar veins, veins that developed in scars that formed after previous operations, as well as collaterals that form around entero- or colostomy.

IVgroup: veins that redistribute portal venous blood into the left renal vein. Blood flow through these collaterals is carried out both directly from the splenic vein to the renal vein, and through the phrenic, pancreatic, gastric veins or the vein of the left adrenal gland.

As a result, blood from the gastroesophageal and other collaterals through the azygos or semi-gypsy vein enters the superior vena cava. A small amount of blood enters the inferior vena cava; blood may flow into it from the right lobar branch of the portal vein after the formation of an intrahepatic shunt. The development of collaterals to the pulmonary veins has been described.

Extrahepatic obstruction

With extrahepatic portal vein obstruction, additional collaterals are formed, along which blood bypasses the obstruction site in order to enter the liver. They drain into the portal vein at the porta hepatis distal to the site of obstruction. These collaterals include the portal veins of the liver; veins accompanying the portal vein and hepatic arteries; veins running in the ligaments supporting the liver; phrenic and omental veins. Collaterals associated with the lumbar veins can reach very large sizes.

Rice. 10-3. Portosystemic collateral circulation in liver cirrhosis.

Consequences of portal blood flow disturbance

When the amount of portal blood flowing to the liver decreases due to the development of collateral circulation, the role of the hepatic artery increases. The liver decreases in volume, its ability to regenerate decreases. This is likely due to insufficient supply of hepatotropic factors, including insulin and glucagon, produced by the pancreas.

The presence of collaterals usually implies portal hypertension, although sometimes the portal vein pressure may decrease if the collaterals are significant. At the same time, short-term portal hypertension can occur without the development of collateral circulation.

With significant portosystemic shunting, hepatic encephalopathy, sepsis caused by intestinal bacteria, and other circulatory and metabolic disorders may develop.

One of the largest and the most important vessels V human body is the portal vein of the liver.

Without it, the normal functioning of the digestive tract and the necessary purification of the blood are impossible.

The portal vein can be called a vessel that collects blood from all unpaired organs and delivers fluid to the liver for filtration.

Pathologies of the portal vein do not go unnoticed, but leave a mark on the functioning of the entire body.

The role of the portal vein in the structure of blood circulation

Certain organs of the human body are created in pairs: kidneys, lungs, eyes. But there are also single components: liver, heart, stomach.

This is the normal structure and functioning of the body. All unpaired organs of the abdominal region have ducts for connection with common system venous circulation.

The collected blood from each organ goes to the liver. There, the portal vein diverges into right and left branches, which are divided into small venous vessels.

In terms of size, it is the largest vessel in the large circle of blood flow. The length of the human visceral trunk can be more than four to six cm, and the diameter from ten to twenty mm.

The portal vein system is quite complex: it is an additional circle of blood flow created to cleanse the blood of poisons and allergens.

Pathologies in the functioning of the organ on the path of blood from the digestive organs contribute to the creation of conditions for poisoning the body with decay and metabolic products.

The main feature of the structure of the portal vein is that a venous vessel enters the liver, and blood through it exits into the hepatic veins.

Changes in the size or functioning of the portal vein can signal diseases of various kinds - thrombosis of the portal vein of the liver, diseases of the pancreas, spleen and others.

The hepatic vessel does not function separately from the others vascular systems. Nature has thought of a way to release excess blood into other vessels in the event of hemodynamic disturbances.

This helps to alleviate the patient’s condition with diseases of the liver or hepatic vessel.

The normal functioning of blood flow through the veins is based on the uninterrupted flow of blood through the vascular system.

If an obstacle appears in the path of blood, the entire blood flow system of the body is upset.

This condition can provoke portal hypertension syndrome, in which the main hepatic vessel is filled with blood, which leads to the need for blood to flow through other great vessels.

This replacement can cause internal bleeding and serious illnesses, such as varicose veins and hemorrhoids.

The portal vein has vital importance in the hemodynamic system, as well as in the process of filtering blood from toxins and poisons that enter a person.

With minor disturbances in the functioning of the vessel, damage can be caused to the body in the form of toxicity or blockage of blood vessels, as well as other problems.

Pathologies of the portal vein

The portal vein is susceptible to various diseases, such as:

intrahepatic and extrahepatic thrombus formation;
congenital abnormalities;
aneurysms;
portal hypertension syndrome;
cavernous transformation;
various inflammatory processes.

Portal vein thrombosis is a serious pathology, which is characterized by the appearance of blood clots in the vessels that interfere with the movement of fluid to the liver. For this reason, the pressure in the vessels increases.

Causes of thrombosis:

cirrhosis of the liver;
oncological diseases of the gastrointestinal tract;
inflammatory diseases of internal organs;
surgery and trauma;
blood clotting problems;
infectious diseases.

The disease manifests itself as sharp, persistent pain in the liver, nausea, vomiting, weakness, bleeding, and fever.

Portal hypertension is an increase blood pressure in the design of blood vessels, which can contribute to the formation of blood clots in the portal vein.

The causes of the disease can be cirrhosis, thrombosis, various hepatitis, diseases of the cardiovascular system.

Symptoms that manifest hypertension include a feeling of heaviness in the right side, weight loss, lack of appetite, nausea, and lethargy.

Cavernoma is a large number of small vessels that intertwine with each other and partially compensate for the lack of hemodynamics in the portal system.

This phenomenon is appearance looks like a malignant tumor process. Diagnosis of the disease in children may be a sign of inherited pathologies of the hepatic vessels.

Symptoms inflammatory diseases in the portal vein are not clearly expressed, so it is difficult to suspect a painful process.

More recently, the disease was diagnosed at autopsy, but with the advent of magnetic resonance imaging, diagnosis has moved to a new level.

Some symptoms that will help identify inflammation:

fever;
sharp pain in the abdominal area;
severe toxicity.

Scientists have discovered two reasons for the development of portal vein diseases - local and systemic factors.

In addition, the normal operation of the vessel may be disrupted due to oncological diseases and unsuccessful surgery.

Diseases of the hepatic vessel can be acute and chronic.

The acute manifestation corresponds to the name, since the disease is accompanied by unexpected, sharp pain in the abdominal area, fever and chills, enlarged spleen, nausea, vomiting and diarrhea.

All symptoms occur simultaneously, which significantly complicates the patient’s condition. If timely therapy is not prescribed, adverse consequences may occur.

The chronic form of the disease is no less dangerous, in particular because it can be characterized by the absence of symptoms.

Are detected chronic diseases portal vein by chance, for example on an abdominal ultrasound or when diagnosing another disease.

Lack of symptoms explained defense mechanisms organism, which include the ability of the hepatic artery to dilate and the growth of cavernoma.

However, sooner or later the defense mechanism weakens, which is why the patient feels the onset of symptoms of pathology.

Treatment and prevention of diseases

In order to most accurately expose the presence of a characteristic pathogenic process, inpatient diagnostics are needed.

To begin with, the doctor determines all the patient’s symptoms and then sends him for a thorough clinical examination.

To diagnose disease of the main hepatic vessel, modern examination methods are used:

ultrasound examination of the abdominal organs;
CT scan;
Dopplerography;
Magnetic resonance imaging;
x-ray using contrast agents.

Laboratory tests have their own characteristics. General urine and blood tests are secondary, but they do not have a major role in establishing a diagnosis.

Scintigraphy or hepatoscintigraphy can be used to make the correct diagnosis.

If the disease worsens, you need to contact a medical facility to prescribe adequate treatment.

The treatment strategy consists of combined therapy using medicines, surgical intervention, elimination of consequences and complications.

Diseases require immediate treatment, otherwise complications can be fatal.

At mild form attacks of the disease can go away on their own, in which case the patient is confident of a cure.

However, the results of self-treatment are rarely noticed, so visiting medical institution Necessarily.

Classical therapy is aimed at urgently thinning the blood and preventing its excessive clotting.

To achieve a positive result, it is recommended to use anticoagulants and antiplatelet agents to suppress the attack.

If internal bleeding is present, hemostatic procedures must be performed in a hospital.

If traditional treatment is unsuccessful, then the doctor may perform surgery to immediately restore the impaired blood flow.

For this purpose, special vascular prostheses were created. The operation is extremely complex, and the recovery period can last up to six months.

To prevent the occurrence or recurrence of hepatic vascular diseases, it is necessary to monitor liver function.

The main preventive action should be aimed at lowering blood pressure in the hepatic circulatory system.

To do this, it is necessary to ensure the normal functioning of the esophagus and gastrointestinal tract. To achieve this effect, it is recommended to monitor your lifestyle.

It is necessary to eat a balanced and rational diet, avoid bad habits and visit a medical facility regularly.