Splenic Artery Aneurysm

A splenic artery aneurysm is a bulge in the artery that supplies blood to your spleen. It may cause no symptoms and go unnoticed for a long time. Or it may cause symptoms like upper abdominal pain and nausea. A splenic artery aneurysm that breaks open (ruptures) is a surgical emergency.

Splenic artery aneurysms affect between 1 in 1,000 and 1 in 2,500 people. They’re the most common type of visceral artery aneurysm. Splenic artery aneurysms affect females four times as often as males.

Types of this condition

There are two types of splenic artery aneurysms:

• True aneurysm: This affects all three layers of the splenic artery wall.
• Pseudoaneurysm: This affects just one or two of the layers. It’s more likely to rupture than a true aneurysm. It also grows fast. This means it’s not always easy to predict when it might rupture based on its size.

Symptoms of splenic artery aneurysm

Only about 2 in 10 people with a splenic artery aneurysm have symptoms. The most common symptom is pain in the upper left part of your belly. The pain may spread toward your left shoulder. You may also have nausea, vomiting and GI bleeding.

If the splenic artery aneurysm ruptures, you may have:

• Upper belly pain: This is sudden and grabs your attention.
• Internal bleeding: This can make your belly look swollen or feel tender to the touch.
• Shock: This causes fast breathing, confusion, sweating, cool skin and fainting.

Seek emergency care immediately if you have these symptoms.

Symptoms of a rupture may occur all at once or in stages. If it’s in stages, your symptoms may come on suddenly but then briefly ease. This stable period is brief. Your body soon goes into shock.

Causes of splenic artery aneurysm

Weakness in the wall of your splenic artery leads to an aneurysm. The cause of this weakness isn’t always clear. But we know there are many risk factors.

Risk factors

Pregnancy is one of the top risk factors for a splenic artery aneurysm. This may be due to increased blood flow or hormonal changes during pregnancy. Your risk is higher if you’ve been pregnant before.

Other medical conditions that raise your risk include:

• Atherosclerosis
• Connective tissue diseases
• Endocarditis
• Fibromuscular dysplasia
• High blood pressure
• Pancreatitis
• Portal hypertension
• Receiving a liver transplant
• Vasculitis

Complications of this condition

Like other aneurysms, a splenic artery aneurysm is dangerous because it can rupture. This means the weak part of the artery breaks open and bleeds into surrounding areas. This is a surgical emergency that requires immediate care and can be life-threatening.

You face a higher risk of rupture if you:

• Are pregnant, particularly in the last trimester
• Have symptoms
• Have portal hypertension

How doctors diagnose this condition

You need a physical exam and imaging tests to diagnose a splenic artery aneurysm. Your provider will likely use a noninvasive test like a CT angiogram or magnetic resonance angiogram (MRA). These show your splenic artery’s size and blood flow in detail. You may need a more invasive test, like a catheter-based angiogram, if your provider is planning treatment.

By definition, a splenic artery aneurysm means your artery is 1 centimeter or more in diameter. Your provider will discuss test results with you and let you know if you need treatment.

How is a splenic artery aneurysm treated?

Vascular surgeons repair splenic artery aneurysms using procedures and surgeries like:

• Endovascular procedure: This is usually the best option to manage an aneurysm before it ruptures. Your provider uses metal coils or stents to block off the aneurysm so blood can’t flow through it. This eases pressure on the artery walls.
• Laparoscopic surgery: This option is less invasive than open surgery. It has an easier recovery.
• Open surgery: You may need surgery if you had an unsuccessful endovascular procedure or endovascular methods aren’t an option for you. Your provider removes the damaged part of your artery by opening your abdomen. They may also need to remove your spleen.

When is a splenic artery aneurysm treated?

Aneurysms greater than 2 centimeters in diameter typically need repair. That’s because they’re at risk of rupture. If your aneurysm is smaller than this, you may still need treatment if you’re pregnant or could become pregnant. Providers also treat pseudoaneurysms of any size because it’s harder to predict when they might rupture.

Other factors influence the need for treatment. For example, your provider may suggest a repair if you have portal hypertension or need a liver transplant. An aneurysm that grows quickly — at least half a centimeter per year — may also need treatment. Your provider considers how dangerous the aneurysm is for you when deciding to treat it.

If your aneurysm isn’t at risk of rupturing, your provider will likely monitor it. They’ll start treatment if your risk for a rupture goes up at any point.

When should I see my healthcare provider?

Your provider will tell you how often to come in for follow-up visits and imaging tests. These are important even after successful treatment. Your provider will check for any signs of complications. They’ll also make sure you receive any further treatment you might need.

What can I expect if I have this condition?

Your outlook depends on many things, including:

• Aneurysm size and location
• How quickly it grows
• Whether or not it ruptures
• Your overall health and health history

Many splenic artery aneurysms grow slowly. One study found that smaller aneurysms that providers monitored grew at a rate of 0.2 millimeters per year. That same study found that nearly 9 in 10 people with a splenic artery aneurysm were still alive 10 years after diagnosis.

Up to 1 in 4 people with a ruptured splenic artery aneurysm don’t survive. Survival is worse during pregnancy. Rupture is fatal to the mother 80% of the time and to the fetus 90% of the time.

These stats can sound scary, but early diagnosis and treatment can save your life. Talk to your provider if you have any concerns about your risk for this condition or your treatment plan.