Table of ContentsView AllTable of ContentsFunctionLocation and AnatomyRelated ConditionsTreatment
Table of ContentsView All
View All
Table of Contents
Function
Location and Anatomy
Related Conditions
Treatment
The portal vein, or hepatic portal vein, is the main blood vessel of the portal venous system (PVS), which delivers blood to the liver from the stomach, intestines, spleen, gallbladder, and pancreas. Portal vein blood contains nutrients and toxins extracted from digested contents, which the liver filters and processes. Toxins are discarded as waste, while nutrients are broken down for use in the body.
The portal vein is vulnerable to diseases likecirrhosis, which can change the structure of the vessel and reduce the flow of blood into the liver, leading to serious medical complications.
Jan-Otto / Getty Images
The Main Function of the Portal Vein
Like any organ, theliverrequires a constant flow of blood to maintain life. The liver has a dual blood supply derived from the portal vein and thehepatic artery. About 75% of that blood flow comes from the portal vein, which is responsible for providing much of the liver’s oxygen and nutrients.
The liver helps metabolize carbohydrates, proteins, and fats in the body. Nutrients and other substances that are absorbed in the intestines travel via the portal vein to the liver, where they can be processed before being released to the rest of the body.
The portal vein and its tributaries carry blood to the liver first, allowing the liver to process nutrients and neutralize toxins before they pass on to the rest of the body.
The splenic vein and superior mesenteric vein join behind the neck of the pancreas to form the main portal vein. This then travels within thehepatoduodenalligament toward the portion of the liver called the liver hilum.
There, the vein splits into the right and left portal vein branches. These enter the main section of the liver. The right and left portal veins then branch further to supply the different lobes of the liver.
Most veins in the body, called systemic veins, carry blood toward the heart. The portal vein and its contributing veins are different because they carry blood to the liver first.
Collectively, these veins are called the hepatic portal venous system. If you have chronic liver disease, this system is at risk for serious complications.
Anatomical Variations
Up to 29% of people have variations in the branching pattern of the portal vein.These variants don’t usually cause symptoms or disease but become important if liver surgery is being planned.
For someone born with congenital agenesis of the portal vein, their prognosis depends on the nature of the liver and cardiac disease. The location of the shunts also affects your overall health.
The condition can sometimes be managed with medications or minimally invasive surgical procedures. In severe cases, a liver transplant may be necessary.
A number of conditions can affect the hepatic portal venous system while problems that originate with the portal vein can lead to other health complications.
Cirrhosis and Liver Disease
Chronic liver disease including cirrhosis can impede portal vein function and your general health. One issue isascites, the build-up of fluid in the abdominal cavity.
Cirrhosiscauses pressure to be exerted on the portal venous; it also causes sodium retention. These factors lead to a situation in which fluid seeps out, causing ascites to build up in the abdominal cavity. These fluid ascites can cause a variety of issues including:
Heading Encephalopathy
Portal Hypertension
Liver cirrhosis and other chronic liver diseases may disrupt blood flow in the portal vein. In addition, cirrhosis distorts the liver’s structure, causing blood congestion in the portal vein and, ultimately, raising your blood pressure. This state is calledportal hypertension.
Portal hypertension is responsible for the major complications of cirrhosis such as:
Large portosystemic collaterals around the stomach and esophagus (calledvarices) can cause gastrointestinal bleeding that may be life-threatening.
Portal Vein Thrombosis
Barring cirrhosis, other risk factors include malignancy, intra-abdominal infections, abdominal trauma, and intra-abdominal surgery (e.g., splenectomy).
In adults, thrombosis of the portal vein may result from genetic conditions that increase the likelihood of clot formation.
Treatment of Portal Vein Disorders
Treating portal vein disorders starts with treating the underlying issue.
In cases of cirrhosis, the source of the cirrhosis must be eliminated. Thus, you may need to abstain completely from alcohol or undergo special treatment for a virus. These changes can ease symptoms significantly.
Medications may also reduce blood flow into portosystemic collaterals or reduce blood flow within the liver. Your healthcare provider may recommend stopping or switching a medication.
Patients with refractory ascites or GI bleeding may benefit from the surgical placement of shunts between the portal and systemic circulation. For example, atransjugularintrahepaticportosystemic shunt (TIPS) is a shunt placed inside the liver that carries blood directly from the portal veins into the systemic circulation.
Summary
The portal vein is the main blood vessel carrying blood to the liver from the stomach, intestines, spleen, gallbladder, and pancreas.
Portal vein blood contains both nutrients and toxins derived from digestion, which the liver filters and processes.
Because of its location, cirrhosis and liver disease have the greatest impact on the portal vein. These diseases can change the portal structure and reduce the flow of blood into the liver.
Liver health is essential to keeping this part of the circulatory system functioning correctly and avoiding a host of serious medical complications.
8 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Blumgart LH, J Belghiti.Liver Blood Flow: Physiology, Measurement, and Clinical Relevance.Surgery of the Liver, Biliary Tract, and Pancreas. Saunders Elsevier; 2007.Carneiro C, Brito J, Bilreiro C, et al.All about portal vein: a pictorial display to anatomy, variants and physiopathology.Insights Imaging. 2019;10(1):38. doi:10.1186/s13244-019-0716-8Cheluvashetty, SB.Unusual branching pattern of the portal vein: its importance.JCDR. 2017;11(8):TD01–TD02. doi:10.7860/JCDR/2017/29011.10390Kwapisz L, Wells MM, AlJudaibi B.Abernethy malformation: congenital absence of the portal vein.Can J Gastroenterol Hepatol. 2014;28(11):587-588. doi:10.1155/2014/675812Iqbal, S.Surgical implications of portal vein variations and liver segmentations: a recent update.JCDR. 2017;11(2): AE01–AE05. doi:10.7860/JCDR/2017/25028.9453Ferenci, P.Hepatic encephalopathy.Gastroenterol Rep (Oxf). 2017;5(2):138-147. doi:10.1093/gastro/gox013de Franchis R, Bosch J, Garcia-Tsao G, Reiberger T, Ripoll C; Baveno VII Faculty.Baveno VII - Renewing consensus in portal hypertension [published correction appears in J Hepatol. 2022 Jul;77(1):271. doi: 10.1016/j.jhep.2022.03.024].J Hepatol. 2022;76(4):959-974. doi:10.1016/j.jhep.2021.12.022Intagliata NM, Caldwell SH, Tripodi A.Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis.Gastroenterology. 2019;156(6):1582-1599.e1. doi:10.1053/j.gastro.2019.01.265
8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Blumgart LH, J Belghiti.Liver Blood Flow: Physiology, Measurement, and Clinical Relevance.Surgery of the Liver, Biliary Tract, and Pancreas. Saunders Elsevier; 2007.Carneiro C, Brito J, Bilreiro C, et al.All about portal vein: a pictorial display to anatomy, variants and physiopathology.Insights Imaging. 2019;10(1):38. doi:10.1186/s13244-019-0716-8Cheluvashetty, SB.Unusual branching pattern of the portal vein: its importance.JCDR. 2017;11(8):TD01–TD02. doi:10.7860/JCDR/2017/29011.10390Kwapisz L, Wells MM, AlJudaibi B.Abernethy malformation: congenital absence of the portal vein.Can J Gastroenterol Hepatol. 2014;28(11):587-588. doi:10.1155/2014/675812Iqbal, S.Surgical implications of portal vein variations and liver segmentations: a recent update.JCDR. 2017;11(2): AE01–AE05. doi:10.7860/JCDR/2017/25028.9453Ferenci, P.Hepatic encephalopathy.Gastroenterol Rep (Oxf). 2017;5(2):138-147. doi:10.1093/gastro/gox013de Franchis R, Bosch J, Garcia-Tsao G, Reiberger T, Ripoll C; Baveno VII Faculty.Baveno VII - Renewing consensus in portal hypertension [published correction appears in J Hepatol. 2022 Jul;77(1):271. doi: 10.1016/j.jhep.2022.03.024].J Hepatol. 2022;76(4):959-974. doi:10.1016/j.jhep.2021.12.022Intagliata NM, Caldwell SH, Tripodi A.Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis.Gastroenterology. 2019;156(6):1582-1599.e1. doi:10.1053/j.gastro.2019.01.265
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Blumgart LH, J Belghiti.Liver Blood Flow: Physiology, Measurement, and Clinical Relevance.Surgery of the Liver, Biliary Tract, and Pancreas. Saunders Elsevier; 2007.Carneiro C, Brito J, Bilreiro C, et al.All about portal vein: a pictorial display to anatomy, variants and physiopathology.Insights Imaging. 2019;10(1):38. doi:10.1186/s13244-019-0716-8Cheluvashetty, SB.Unusual branching pattern of the portal vein: its importance.JCDR. 2017;11(8):TD01–TD02. doi:10.7860/JCDR/2017/29011.10390Kwapisz L, Wells MM, AlJudaibi B.Abernethy malformation: congenital absence of the portal vein.Can J Gastroenterol Hepatol. 2014;28(11):587-588. doi:10.1155/2014/675812Iqbal, S.Surgical implications of portal vein variations and liver segmentations: a recent update.JCDR. 2017;11(2): AE01–AE05. doi:10.7860/JCDR/2017/25028.9453Ferenci, P.Hepatic encephalopathy.Gastroenterol Rep (Oxf). 2017;5(2):138-147. doi:10.1093/gastro/gox013de Franchis R, Bosch J, Garcia-Tsao G, Reiberger T, Ripoll C; Baveno VII Faculty.Baveno VII - Renewing consensus in portal hypertension [published correction appears in J Hepatol. 2022 Jul;77(1):271. doi: 10.1016/j.jhep.2022.03.024].J Hepatol. 2022;76(4):959-974. doi:10.1016/j.jhep.2021.12.022Intagliata NM, Caldwell SH, Tripodi A.Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis.Gastroenterology. 2019;156(6):1582-1599.e1. doi:10.1053/j.gastro.2019.01.265
Blumgart LH, J Belghiti.Liver Blood Flow: Physiology, Measurement, and Clinical Relevance.Surgery of the Liver, Biliary Tract, and Pancreas. Saunders Elsevier; 2007.
Carneiro C, Brito J, Bilreiro C, et al.All about portal vein: a pictorial display to anatomy, variants and physiopathology.Insights Imaging. 2019;10(1):38. doi:10.1186/s13244-019-0716-8
Cheluvashetty, SB.Unusual branching pattern of the portal vein: its importance.JCDR. 2017;11(8):TD01–TD02. doi:10.7860/JCDR/2017/29011.10390
Kwapisz L, Wells MM, AlJudaibi B.Abernethy malformation: congenital absence of the portal vein.Can J Gastroenterol Hepatol. 2014;28(11):587-588. doi:10.1155/2014/675812
Iqbal, S.Surgical implications of portal vein variations and liver segmentations: a recent update.JCDR. 2017;11(2): AE01–AE05. doi:10.7860/JCDR/2017/25028.9453
Ferenci, P.Hepatic encephalopathy.Gastroenterol Rep (Oxf). 2017;5(2):138-147. doi:10.1093/gastro/gox013
de Franchis R, Bosch J, Garcia-Tsao G, Reiberger T, Ripoll C; Baveno VII Faculty.Baveno VII - Renewing consensus in portal hypertension [published correction appears in J Hepatol. 2022 Jul;77(1):271. doi: 10.1016/j.jhep.2022.03.024].J Hepatol. 2022;76(4):959-974. doi:10.1016/j.jhep.2021.12.022
Intagliata NM, Caldwell SH, Tripodi A.Diagnosis, Development, and Treatment of Portal Vein Thrombosis in Patients With and Without Cirrhosis.Gastroenterology. 2019;156(6):1582-1599.e1. doi:10.1053/j.gastro.2019.01.265
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