What Is Splenic Artery Aneurysm?

Introduction

The spleen is an organ located in the abdomen that is responsible for helping the human body fight against foreign substances attacking it; therefore, it has a role in the maintenance of a healthy state.¹ 

Oxygen, as well as all the nutrients the spleen needs to function, is provided by the splenic artery with all of its several collateral branches. ^{2 3} Whenever a splenic artery aneurysm occurs, there might be a commission of the function of the vase, which is now characterized by a significant increase in its diameter. Typically, the splenic artery’s width is about 0.5 centimetres, but in a splenic artery aneurysm, it increases to at least 0.75 centimeters at least.⁴

Although the splenic artery aneurysm can be considered a rare pathology, as it occurs in less than 1 per cent of the population, it also represents a life-threatening condition due to the common lack of signs and symptoms that causes it to often go undetected and, consequently, grow and rupture.

When signs and symptoms do occur, these can include abdominal pain, vomiting blood, and loss of blood from the anus. Symptomatic patients present a higher risk of rupture of the aneurysm,  which requires urgent care.^{4 5}

Causes of splenic artery aneurysm

The specific cause of the splenic artery aneurysm is unknown. The development of splenic artery aneurysms involves the weakening of the splenic artery’s walls. 

Several factors increase the risk of someone developing the condition:⁴

• Atherosclerosis
• Portal hypertension
• Liver transplantation
• Pregnancy
• Connective tissue disorders
• Chronic pancreatitis
• Physical trauma
• Older age
• Assigned female at birth

Signs and symptoms of splenic artery aneurysm

As previously stated, splenic artery aneurysms can often be asymptomatic; however, when signs and symptoms do occur, they can  cause several conditions:⁴

• Abdominal pain
• Abdominal mass
• Vomiting blood
• Blood from the anus

Signs and symptoms indicate 

Diagnosis of splenic artery aneurysm

Diagnosing splenic artery aneurysms involves ruling out other conditions that may present similarly:⁴

• Congenital antitrypsin deficiency
• Cystic medial necrosis
• Ehlers-Danlos syndrome
• Marfan syndrome
• Neurofibromatosis
• Polyarteritis nodosa
• Systemic lupus erythematosus
• Takayasu arteritis

Computerized tomography (CT), magnetic resonance imaging (MRI), and contrast angiography are imaging techniques typically used to diagnose splenic artery aneurysms.⁴

Computerized tomography

CT scans use X-rays to take images of the inside of the body. In order to diagnose splenic artery aneurysms, a contrast-enhanced CT is usually required, but first, the patient receives an injection of a contrast agent so that the splenic artery can be seen clearly. 

A CT scan will involve the patient lying on their back on a flat bed that is passed through the thin ring-shaped CT scan. During these scans, patients are required to lie very still and breathe normally. 

The typical duration of a CT scan takes around 10 to 20 minutes to complete.^{4 6}

Magnetic resonance imaging

MRI scans use magnetic fields and radio waves to produce images of the inside of the body. 

Similarly to a CT scan, during an MRI scan, the patient will be asked to lie on their back on a flat bed that is passed through the MRI scanner. On the negative side, the MRI scanner is much thicker than the CT scanner. Therefore, it may cause a feeling of discomfort and claustrophobia. 

Contrary to CT scans, in this case, the radiographer may sometimes ask the patient to hold their breath for a few seconds to help capture images. 

Typically, MRI scans take longer than CT scans to complete, lasting about 15 to 90 minutes.⁷

Contrast angiography

Contrast angiography is a type of X-ray specifically used to take images of blood vessels. It requires the injection of a contrast agent into the blood vessels so that they can be clearly seen on the monitor. 

Before undergoing a contrast angiography, the patient may be given a sedative to help them relax. 

This procedure involves the patient lying on a flat table where a small cut is made over an artery, usually near the groin or wrist; local anaesthetic is administered before this small cut in order to numb the pain. 

A thin tube called a “catheter” is then inserted into the artery, and finally, the contrast agent is injected into the catheter so that clear images of vessels can be taken. 

This procedure usually lasts between 30 minutes and 2 hours.⁸

Management and treatment of splenic artery aneurysm

Surgical

Surgery is the typical management and only treatment option for splenic artery aneurysms. Depending on the nature of the splenic artery aneurysm, the surgical procedure employed can vary. 

The surgical option tends to be considered when a splenic artery aneurysm’s diameter exceeds 2 centimetres. Consulting with a surgeon can determine what options are available for surgery and what the risks and benefits are.^{4 5}

Non-surgical

Non-surgical treatment is typically considered when a patient is not likely to experience a rupture of the splenic artery aneurysm. 

If a doctor determines that the patient has a slow-growing splenic artery aneurysm, they proceed with a conservative approach by monitoring the situation and the diameters annually through the imaging techniques mentioned above. 

Unlike surgery, non-surgical management does not reduce the risk of the splenic artery aneurysms rupturing.

Complications of splenic artery aneurysm

Rupturing is a complication of splenic artery aneurysms. 

Ruptures are rare, occurring in 2 to 10 per cent of patients with splenic artery aneurysms, but they are more likely to occur in those who experience signs or symptoms or who are pregnant. 

Rupturing of splenic artery aneurysms can cause sudden abdominal pain in the upper left region, pain in the left shoulder, nausea, vomiting, and sudden collapsing. This eventuality requires urgent care.⁴

FAQs

Are splenic artery aneurysms common?

Splenic artery aneurysms are rare, occurring in less than 1 per cent of the population. The majority of cases, that is approximately 80 per cent, occur in those assigned as female at birth, particularly pregnant patients.⁴

What are the risk factors for developing a splenic artery aneurysm?

There are several risk factors for developing a splenic artery aneurysm:⁴

• Atherosclerosis
• Portal hypertension
• Liver transplantation
• Pregnancy
• Connective tissue disorders
• Chronic pancreatitis
• Physical trauma
• Older age
• Assigned female at birth

Can a splenic artery aneurysm rupture?

A splenic artery aneurysm can rupture. For patients without signs and symptoms, the risk of rupture is low, ranging from 2 to 10 per cent, with this increasing to around 80 per cent for patients with signs and symptoms. Furthermore, the larger the splenic artery aneurysm, the greater the risk of rupture. Pregnant people with splenic artery aneurysms are particularly prone to the splenic artery aneurysm rupturing.⁴

Is it necessary to remove the spleen if a splenic artery aneurysm is detected?

It is not necessary to remove the spleen if a splenic artery aneurysm is detected. Typically, surgery can target the splenic artery aneurysm without removal of the spleen being necessary. Surgery is often only done when the size of the aneurysm exceeds 2 centimetres.

What is the outlook like for those with a splenic artery aneurysm?

The outlook for those with a splenic artery aneurysm varies depending on several factors. The size of a splenic artery aneurysm predicts the chance of a patient having signs and symptoms and the chance of the splenic artery aneurysm rupturing.

Are there any lifestyle modifications that can help a splenic artery aneurysm?

Lifestyle modifications cannot serve as a treatment for splenic artery aneurysms. However, quitting smoking has been linked to a reduced risk of developing the condition.⁵

Summary

Splenic artery aneurysms are rare but can be life-threatening. They are characterized by enlargement of the diameter of the splenic artery. They can cause abdominal pain, vomiting blood, and blood from the anus, or no signs and symptoms at all, causing them to often go undetected. They can eventually rupture, which is a serious event requiring urgent care. The risk of a splenic artery aneurysm artery rupturing is increased greatly when a patient experiences signs and symptoms. 

Diagnosing splenic artery aneurysm is often done by employing imaging techniques. The treatment is typically surgical, often being reserved for when a splenic artery aneurysm’s diameter exceeds 2 centimetres.