What is an aneurysm?
An aneurysm is the abnormal ballooning, widening, or bulging of a part of the artery usually caused by arterial wall weakness. When an aneurysm enlarges and ruptures, disastrous consequences, such as internal bleeding, usually happen.
Aneurysms are usually found in the aorta (the body's largest artery) or arteries of the brain. However, they can also form in other parts of the body, such as the legs and spleen. They can also occur in people who have high cholesterol, high blood pressure, and atherosclerosis. Risk factors include smoking, poor or unhealthy diet, obesity, and the use of drugs like cocaine, which can abnormally increase blood pressure.
Aneurysms also run in families, even though some individuals are born with disorders or health conditions that can predispose them to the formation of aneurysms. Other people may also develop an aneurysm later in life without any symptoms or warning.
Let's take a look at the different types of brain aneurysms below.
Types of Aneurysms
1. Brain Aneurysm
A brain aneurysm is a weak spot in the brain's arterial wall. This weak spot resembles a balloon that is thin and stretched out. Brain aneurysm is also called as cerebral aneurysm or intracranial aneurysm. If a brain aneurysm ruptures, it is considered a medical emergency, which requires immediate medical treatment. If not immediately treated, it can result in brain damage, stroke, and even death.
However, aneurysms do not always rupture and do not always need active treatment. People may not even realize that they have brain aneurysm because in most cases, the aneurysm does not cause any health problems or symptoms.
Aneurysms that have an increased risk of rupture are those that are more than 7 millimeters in diameter and are located in the anterior or posterior arteries along with a daughter sac, which is another bulge that has a complex shape.
Brain aneurysm symptoms include the worst headache that you have had, double or blurred vision, weakness, difficulty speaking, numbness, pain behind or above the eye, and dilated pupils.
There are also two types of brain aneurysms:
- Saccular Aneurysm: The most common type of brain aneurysm, which accounts for approximately 80-90 percent of intracranial aneurysms. It is also the most common cause of nontraumatic subarachnoid hemorrhage (SAH). Saccular aneurysms are also called as berry aneurysms due to their shape, which resembles a berry or sac forming in between a Y-shape segment with a neck and stem.
- Fusiform Aneurysm: This is the less common type of brain aneurysm that is less likely to burst. Unlike saccular aneurysm, fusiform aneurysm does not have a stem. It looks like an expanded blood vessel in all directions.
2. Aortic Aneurysm
The largest artery in the body is called the aorta, which carries oxygen-rich blood all over the body. Depending on the sex and size of an individual, the normal size of the aorta is around 2-3 cm in diameter.
When the aorta is abnormally expanded up to 50 percent from its normal size and when it is permanently dilated, an aortic aneurysm can occur. When an aortic aneurysm occurs in the chest, it is called thoracic aortic aneurysm, and when it occurs in the abdomen, it is called an abdominal aortic aneurysm. An abdominal aortic aneurysm is more common in men who are older than 65 years old and is more common than thoracic aortic aneurysms. However, women are more likely to have both types of aortic aneurysm than men.
As the name itself suggests, this particular type of aneurysm mostly occurs in the aorta. It is also said to be associated with atherosclerosis or the hardening of the arteries. This condition can also be inherited or can turn out to be a complication of high blood pressure and smoking. Severe bleeding or hemorrhage can occur when an aortic aneurysm ruptures or leaks.
3. Mycotic Aneurysm
A mycotic aneurysm is a type of aneurysm that is caused by a bacterial infection usually originating from the heart, such as endocarditis. When people have endocarditis, their arterial wall becomes dilated and infected. In most cases, a fatal aneurysm rupture happens when mycotic aneurysms are left untreated. For this reason, early diagnosis and treatment of mycotic aneurysms are very important.
The following are identifiable risk factors for mycotic aneurysms:
- Infective endocarditis (IE)
- A native aneurysm or a pre-existing atherosclerotic plaque
- Iatrogenic arterial injury
- Intravenous drug use
- Arterial infection
- Prosthetic arterial or cardiac devices (grafts and stents)
4. Peripheral Aneurysm
When a blood vessel wall in an organ or other parts of the body dilates and weakens, a peripheral aneurysm can occur. This dilation can interrupt the flow of blood and can cause the formation of blood clots. When a peripheral aneurysm ruptures, it can cause compression of adjacent tissues and serious bleeding. Peripheral aneurysms are rare and often have a genetic cause.
The most common type of peripheral aneurysm is popliteal aneurysm, which develops in an artery behind your knee. This type of aneurysm accounts for approximately 85 percent of all peripheral aneurysms. Around 40-50 percent of abdominal aortic aneurysms are also associated with popliteal aneurysms.
There are also other types of peripheral aneurysms and they include:
- Carotid Artery Aneurysm: This is a type of aneurysm that develops in the neck's carotid artery.
- Femoral Artery Aneurysm: This aneurysm forms in the groin's femoral artery.
- Mesenteric Artery Aneurysm: This type of aneurysm occurs in the artery, which carries oxygen-rich blood to the intestines.
- Visceral Artery Aneurysm: This type of aneurysm affects a portion of the renal, splenic, mesenteric, and hepatic arteries, which supply blood to the kidneys, spleen, intestines, and liver.
- Splenic Artery Aneurysm: The splenic artery, which supplies blood to the spleen is affected by this type of aneurysm. The spleen, as part of the body's immune system, helps filter blood.
How can aneurysms be prevented?
The formation of aneurysms may be prevented by living a healthy lifestyle and consuming a healthy diet. Regular exercises such as cardio workouts are recommended since they encourage a healthy circulation of blood through the heart, arteries, and other blood vessels.
Stopping the use of tobacco products can also reduce the risk of aneurysm formation. Aside from these preventive measures, seeing your healthcare provider for regular annual checkups is also highly recommended.