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Hepatic Portal Vein

Q: With which veins of the superior vena caval system do the esophageal veins anastomose?

Esophageal veins (vv. oesophageales) drain blood into the azygos vein (v. azygos), which is a direct tributary of the superior vena cava. In the region of the abdominal esophagus, these vessels form an important portosystemic anastomosis by connecting directly with the left gastric vein (v. gastrica sinistra), which runs along the lesser curvature of the stomach and empties directly into the portal vein trunk.

Vena portae hepatis

For medical students2 min readUpdated 2026-10-10

The hepatic portal vein is a central venous vessel that collects blood from all unpaired abdominal viscera. It directs this blood flow into the liver for metabolism and detoxification before the blood returns to the systemic circulation.

FormationPosterior to the neck of the pancreas

TerminationEnters the liver, dividing into right and left branches

Outflow from liverVia hepatic veins into the inferior vena cava

AnastomosesConnects with the caval system in the rectum and esophagus

Formation of the Trunk and Main Roots

The portal vein (V. portae hepatis) is formed posterior to the neck of the pancreas (Pancreas). Its trunk is formed by the convergence of major vessels, each draining a specific region of the abdominal cavity:

Superior mesenteric vein (V. mesenterica superior). Drains blood from the small intestine and the right half of the large intestine. Its basin includes jejunal and ileal veins (Vv. jejunales et ileales), as well as colic vessels: the ileocolic vein (V. ileocolica) with the appendicular vein (V. appendicularis), and the right and middle colic veins (V. colica dextra and V. colica media). Additionally, it receives the pancreaticoduodenal vein (V. pancreaticoduodenalis) and the right gastro-omental vein (V. gastroomentalis dextra).
Splenic vein (V. splenica). Drains the spleen (Splen), part of the pancreas via pancreatic veins (Vv. pancreaticae), and the gastric fundus via short gastric veins (Vv. gastricae breves). It also receives the left gastro-omental vein (V. gastroomentalis sinistra).
Inferior mesenteric vein (V. mesenterica inferior). Collects venous blood from the left half of the colon via the left colic (V. colica sinistra), sigmoid (Vv. sigmoideae), and superior rectal (V. rectalis superior) veins. As a normal anatomical variant, it frequently drains into the splenic vein.

Direct Tributaries from the Stomach

Certain vessels do not belong to the drainage basins of the three main roots, but instead empty directly into the portal vein trunk or its primary branches. These gastric veins include:

Left gastric vein (V. gastrica sinistra). Runs along the lesser curvature of the stomach and is of critical clinical importance because it forms anastomoses with esophageal veins (Oesophagus).
Right gastric vein (V. gastrica dextra). Anastomoses with the left gastric vein.
Prepyloric vein (V. prepylorica).

Intrahepatic Circulation

Upon reaching the porta hepatis (Hepar), the main vascular trunk divides into two major branches: the right (R. dexter v. portae hepatis) and left (R. sinister v. portae hepatis) branches. In this same region, the cystic vein (V. cystica), draining the gallbladder, and paraumbilical veins (Vv. paraumbilicales), coursing within the round ligament of the liver, join the portal system.

Within the hepatic parenchyma, venous blood flows through a specialized network of vascular sinusoids. Following filtration, cleansing, and metabolic processing, blood is collected by the hepatic veins (Vv. hepaticae). These direct the blood flow into the inferior vena cava (V. cava inferior), returning it to the heart.

Clinically Important Anastomoses

Of particular practical significance are the sites where the branches of the portal system connect with vessels of the systemic circulation—known as portosystemic (portacaval) anastomoses.

A prime example is the rectal venous plexus (Plexus venosus rectalis). Here, blood from the upper rectum drains into the portal system via the superior rectal vein (V. rectalis superior). Meanwhile, the middle and inferior rectal veins (Vv. rectales mediae et inferiores) drain into the caval system. Through these, blood flows into the internal iliac vein (V. iliaca interna), then into the common iliac vein (V. iliaca communis), and ultimately into the inferior vena cava.

Frequently asked questions

What are the major portosystemic anastomoses?

The body contains the following portosystemic anastomoses that establish connections between the portal venous system and the systemic caval veins:

Rectal venous plexus (plexus venosus rectalis) — connects the superior rectal vein with the internal iliac venous drainage basin (middle and inferior rectal veins).
Umbilical portosystemic anastomosis — connects paraumbilical veins (vv. paraumbilicales) with the superficial veins of the anterior abdominal wall.
Esophageal anastomosis — the left gastric vein (v. gastrica sinistra) anastomoses with esophageal veins.

With which veins of the superior vena caval system do the esophageal veins anastomose?

Esophageal veins (vv. oesophageales) drain blood into the azygos vein (v. azygos), which is a direct tributary of the superior vena cava. In the region of the abdominal esophagus, these vessels form an important portosystemic anastomosis by connecting directly with the left gastric vein (v. gastrica sinistra), which runs along the lesser curvature of the stomach and empties directly into the portal vein trunk.

Which veins form the portosystemic anastomosis on the anterior abdominal wall?

The umbilical portosystemic anastomosis on the anterior abdominal wall is formed by connections between paraumbilical veins and subcutaneous veins. Its contributors include:

Paraumbilical veins (vv. paraumbilicales) — carry blood from the portal system.
Superior epigastric vein (v. epigastrica superior) and thoracoepigastric vein (v. thoracoepigastrica) — drain blood into the superior vena caval system.
Inferior epigastric vein (v. epigastrica inferior) and superficial epigastric vein (v. epigastrica superficialis) — drain blood into the inferior vena caval system.

What anatomical structures form the portal triad at the porta hepatis?

The porta hepatis contains the following main anatomical structures forming the neurovascular and biliary pedicle:

Proper hepatic artery (a. hepatica propria).
Portal vein (v. portae).
Common hepatic duct (ductus hepaticus communis).

In addition to these elements, nerves and lymphatic vessels also pass through the porta hepatis.

Where and how does the portal vein trunk originate?

The portal vein trunk is formed posterior to the neck of the pancreas by the convergence of the superior mesenteric and splenic veins (with the inferior mesenteric vein frequently draining into the latter).

Which organs are drained by the portal venous system?

This system collects venous blood from all unpaired abdominal viscera: the entire gastrointestinal tract (except the lower rectum), stomach, pancreas, spleen, and gallbladder.

How does blood from the portal vein return to the systemic circulation?

After passing through the hepatic sinusoids, the filtered blood enters the hepatic veins, which empty into the inferior vena cava, returning blood directly to the right atrium.

Go deeper

Superior mesenteric vein drainage basin: topography of jejunal and ileal branches
Splenic vein drainage basin and blood supply to the pancreas
Structure of the rectal venous plexus
Vascular topography in the region of the porta hepatis and gallbladder