Your portal vein carries blood from organs in your abdomen (belly) to your liver. This blood must pass through your liver for filtering and processing before it returns to your body’s general circulation. So, your portal vein plays a vital role in draining many smaller veins (tributaries) in your belly and sending the blood into your liver.
Your portal vein is a blood vessel that carries blood from many organs in your abdomen (belly) to your liver. Your liver filters and processes this blood before it returns to your heart and recirculates through your body.
Usually, veins carry blood toward your heart rather than to other organs. Your hepatic portal system (portal venous system) is an exception to this rule. The veins in this system send blood to your liver, rather than directly to your heart. Your portal vein is the main blood vessel in this system. To understand your portal vein and its job, it helps to learn a bit about your portal venous system.
Your portal venous system is a network of veins that drain blood from the following organs in your belly:
Numerous smaller veins in your portal venous system collect blood from all of these organs and deliver it to your portal vein. You can think of your portal vein as a pit lane at a racetrack. It leads to your liver, which serves as a pit stop for your blood to receive necessary maintenance.
By the time blood reaches your portal vein, it’s full of nutrients that need processing before your body can use them. This blood also contains toxins, or harmful substances your body doesn’t need. Your liver “tunes up” your blood by converting nutrients to forms your body can use right away or store. It also removes toxins from your blood.
After this tune-up, your blood is ready to go back to your heart. So, it leaves your liver and travels to your inferior vena cava, which delivers blood to the top right chamber of your heart (right atrium).
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Your portal vein delivers blood from organs in your belly to your liver for processing. Therefore, it’s vital to your portal venous system. It’s the main passageway for blood to enter your liver. All the other veins in your hepatic portal system ultimately converge (join paths) and lead to your portal vein. So, it needs to be healthy and working at its best for the whole system to work as it should.
Your portal vein has several tributaries, or veins that drain into it. These include your:
Your portal vein begins just behind the neck of your pancreas and in front of your inferior vena cava. It extends to your porta hepatis (liver hilum). This is an opening in your liver that allows blood vessels and other structures to enter and leave your liver.
Your portal vein forms at the point where your superior mesenteric vein (SMV) and splenic vein meet. From there, your portal vein travels upward and toward the right, behind your hepatic artery, until it reaches your liver.
As it enters your liver hilum, your portal vein splits into two branches. These are your left portal vein and right portal vein. These branches further divide into additional branches that travel to different parts of your liver.
The most common anatomical variation is portal vein trifurcation. This is when your portal vein splits into three branches, rather than two, as it enters your hilum. In this case, the branches are the:
This variation isn’t dangerous, but your healthcare provider needs to know about it before performing some surgeries and procedures. Providers run imaging tests prior to surgery to learn your anatomy and adjust techniques as needed.
Your portal vein is typically 8 centimeters (cm) long and no more than 13 millimeters (mm) wide.
Conditions that can affect your portal vein include:
If your healthcare provider suspects problems with your portal vein, they may order one or more of the following tests:
Your provider will recommend the best treatment for you based on the test results. Treatment varies widely based on the underlying problem. It may include one or more of the following:
Your provider is the best person to talk to about treatment options in your specific situation.
There’s a lot you can do to keep your portal vein healthy. The first step, though, involves talking with your healthcare provider. Ask if you have any risk factors for portal vein problems and what you can do to lower your risk.
Some general tips include:
Your hepatic portal vein is another name for your portal vein. Most people simply call it your portal vein, but you might see “hepatic portal vein” in some medical sources. Both terms refer to the same blood vessel. “Hepatic” means something is related to your liver.
It can be easy to confuse your hepatic portal vein with your hepatic veins. Your hepatic veins (without the word “portal” in the name) are a set of three veins that drain blood from your liver into your inferior vena cava. So, while your hepatic portal vein sends blood into your liver, your hepatic veins carry blood out of it.
A note from Cleveland Clinic
Learning the anatomy of your blood vessels can help you understand your body on a whole new level. You might be learning about your portal vein due to a medical diagnosis. Or, maybe someone you know has a condition that affects this vein.
No matter how you came to the topic, remember that learning is a lifelong process. All the different names and anatomical locations can be a lot to take in. Just learn a little bit at a time and ask your healthcare provider to explain more. The knowledge you gain can help you talk to your provider about your condition or a loved one’s condition. This shared vocabulary can be empowering as you make sense of diagnoses, treatment plans and the path ahead.
Last reviewed by a Cleveland Clinic medical professional on 06/01/2023.
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