An aneurysm is an artery enlargement caused by artery wall weakness. There are often no signs but a ruptured aneurysm can result in fatal complications.
An aneurysm refers to a weakening of an artery wall which causes an artery bulge, or distention.
The majority of aneurysms do not display symptoms and are not severe. However, some may burst at their most serious level, leading to life-threatening internal bleeding.
The Centers for Disease Control and Prevention (CDC) reports that aortic aneurysms lead to more than 25,000 deaths per year in the United States.
Each year about 30,000 brain aneurysms burst in the U.S. An approximate 40% of those cases would cause death within 24 hours.
Fast facts on aneurysms
- Aneurysms affect a variety of arteries. The most significant aneurysms affect the arteries supplying the brain and the heart. An aortic aneurysm affects the body’s main artery.
- The rupture of an aneurysm causes internal bleeding.
- The risk of an aneurysm developing and rupturing varies between individuals. Smoking and high blood pressure are major risk factors for the development of an aneurysm.
- Some types of aneurysm may need surgical treatment to prevent rupture. Doctors will only operate on others if they are life-threatening.
Types
Aneurysms are categorized according to their position in the body. Brain and heart arteries are the two most prominent locations of a severe aneurysm.
The bulge is capable of taking two primary Shapes:
- Fusiform aneurysms bulge all sides of a blood vessel
- Saccular aneurysms bulge only on one side
The risk of rupture depends on the size of the bulge.
Aortic aneurysm
The aorta is the large artery that begins at the heart’s left ventricle and runs through the chest and abdominal cavities. The aorta’s usual diameter is between 2 and 3 centimeters (cm) but with an aneurysm will raise to beyond 5 cm.
Abdominal aortic aneurysm (AAA) is the most severe aneurysm of the aorta. This happens inside the portion of the abdomen running through the aorta. Without surgery, a AAA of over 6 cm has an average survival rate of 20 percent.
AAA can quickly become fatal, but those who survive a hospital transfer have a 50 percent chance of overall survival.
Less commonly, the part of the aorta running through the chest may be affected by thoracic aortic aneurysm (TAA). TAA has an untreated survival rate of 56 percent and 85 per cent following surgery. It is a unusual disorder, because the chest contains just 25 percent of aortic aneurysms.
Cerebral aneurysm
Aneurysms of the arteries that supply the brain with blood are known as intracranial aneurysms. Due to their appearance, they are also known as “berry” aneurysms.
A ruptured aneurysm of the brain can be fatal within 24 hours. Forty percent of brain aneurysms are fatal, and around 66 percent of those who survive will experience a resulting neurological impairment or disability.
Ruptured cerebral aneurysms are the most common cause of a type of stroke known as subarachnoid hemorrhage (SAH).
Peripheral aneurysm
An aneurysm can also occur in a peripheral artery. Types of peripheral aneurysm include:
- Popliteal aneurysm: This happens behind the knee. It is the most common peripheral aneurysm.
- Splenic artery aneurysm: This type of aneurysm occurs near the spleen.
- Mesenteric artery aneurysm: This affects the artery that transports blood to the intestines.
- Femoral artery aneurysm: The femoral artery is in the groin.
- Carotid artery aneurysm: This occurs in the neck.
- Visceral aneurysm: This is a bulge of the arteries that supply blood to the bowel or kidneys.
Rupture of peripheral aneurysms is less likely than aortic aneurysms.
Treatment
Not all cases of aneurysm that has been unsettled require immediate care. However, emergency surgery is needed when an aneurysm ruptures.
Aortic aneurysm treatment options
When no signs are visible, the doctor can control an untreated aortic aneurysm. Conservative management may include medications and preventive steps, or they may follow successful surgical care.
A ruptured aneurysm requires immediate surgery. Patients have poor chances of survival without immediate repair.
The decision to operate on an unbroken aneurysm in the aorta relies on a variety of factors relating to the particular patient and the aneurysm characteristics.
These include:
- the age, general health, coexisting conditions and personal choice of the patient
- the size of the aneurysm relative to its location in the thorax or abdomen, and the aneurysm’s rate of growth
- the presence of chronic abdominal pain or risk of thromboembolism, as these may also necessitate surgery
A large or rapidly growing aortic aneurysm is more likely to need surgery. There are two options for surgery:
- open surgery to fit a synthetic or stent graft
- endovascular stent-graft surgery.
During endovascular surgery, the surgeon accesses a small incision below the hip to the blood vessels. Stent-graft surgery uses a catheter to implant an endovascular graft into the incision. The graft is then placed to seal off the aneurysm into the aorta.
For an open repair of the AAA, a large incision is made to reveal the aorta in the abdomen. A graft for fixing the aneurysm can then be applied.
Endovascular surgery for aortic aneurysm repair bears the risks that follow:
- bleeding around the graft
- bleeding before or after the procedure
- blockage of the stent
- nerve damage, resulting in weakness, pain or numbness in the leg
- kidney failure
- reduced blood supply to the legs, kidneys or other organs
- erectile dysfunction
- unsuccessful surgery that then needs further open surgery
- slippage of the stent
Most of those complications may lead to further surgery, such as bleeding around the graft.
Cerebral aneurysm treatment options
In the case of a brain aneurysm, usually the surgeon should not operate if there is a significant risk of rupture. The future risk of surgical complications arising from brain injury is too high.
As for AAA, the probability of a rupture depends on the aneurysm size and position.
Instead of surgery, patients seek instructions on how to monitor and treat, for example, blood pressure control, the risk factors for a ruptured brain aneurysm.
If a ruptured cranial aneurysm causes hemorrhage of the subarachnoid, surgery is possible. It is a medical emergency.
This treatment will try to close the ruptured artery in the hope that it would avoid another bleed.
Symptoms
Much of the aneurysms clinically stay silent. Symptoms typically do not occur with a ruptured aneurysm.
The unbroken aneurysm, however, will still block drainage to other tissues. These can also form blood clots that can cause blockage of smaller blood vessels. This is a disorder which is called thromboembolism. It can cause ischemic stroke or other serious complications.
Symptoms often correlate with rapidly rising abdominal aneurysms. Many individuals with abdominal aneurysms experience abdominal pain, lower back pain, or a pulsating abdominal sensation.
Additionally, thoracic aneurysms can damage surrounding nerves and other blood vessels, possibly causing trouble swallowing and breathing, and pain in the mouth, throat, and upper back.
Symptoms can also be more relevant to the cause of aneurysm than to the aneurysm itself. Of example, a person may experience fever, malaise or weight loss in the case of an aneurysm caused by vasculitis, or inflammation of the blood vessel.
Complications
Complications after rupture may be the first symptoms of a previously undetected aneurysm. Symptoms appear to result from a rupture rather than simply from aneurysm.
Many people who have an aneurysm experience no symptoms at all. However, complications may include, besides thromboembolism and aorta rupture:
- Severe chest or back pain: Severe chest or back pain may arise following the rupture of an aortic aneurysm in the chest.
- Angina: Certain types of aneurysm can lead to angina, another type of chest pain. Angina can lead to myocardial ischemia and heart attack.
- A sudden extreme headache: If a brain aneurysm leads to SAH, the main symptom is a sudden, severe headache.
Any rupture of an aneurysm may cause pain, low blood pressure, a rapid heart rate, and lightheadedness. Most people with an aneurysm will not experience any complications.
Causes
An aneurysm can occur in any part of the body. A compromised arterial wall will more quickly distend the blood pressure.
Further work is needed to validate why the aneurysm causes an artery wall to collapse. Many aneurysms are present as an arterial defect from birth but they are less common.
Aortic dissection
One known cause of aortic aneurysm is aortic dissection. There are three layers to the arterial wall. Blood will spill through a hole in the artery’s damaged wall, breaking those layers. The cavity around the heart will then be filled up.
When the tear happens on the arterial wall’s innermost layer, the blood flow enter and weakens the wall, raising the likelihood of rupture.
Individuals with aortic dissection often experience pain in the chest that is sudden and appalling. This pain will move along the aorta as dissection continues. It can radiate backwards, for example.
Dissection causes compression. Compression impedes the return of blood to the heart.
Risk factors
There are some options in lifestyle and physical features which may increase an aneurysm’s risk.
- smoking tobacco
- hypertension, or high blood pressure
- poor diet
- inactive lifestyle
- obesity
Smoking is by far the most common risk factor especially in AAA cases. It has been shown that tobacco use not only increases cardiovascular disease and the risk of an aneurysm but also increases the risk of rupture once an aneurysm is successful.
Diagnosis
Sometimes the aneurysms remain undetected. The screening aims at finding individuals who need to be monitored or treated.
The US Task Force on Preventive Services (USPSTF) suggests ultrasound screening for AAA symptoms for all men aged 65 to 75 years who have smoked 100 or more cigarettes in their lives.
For adults, whether they have smoked or not, the task force does not recommend regular screening because adults have a lower risk of AAA.
If there are signs, an MRI scan can detect an aneurysm that has not yet ruptured. CT scans are typically preferred for ruptured aneurysms, particularly when there is a chance that the brain may bleed.
In cases of a serious or ruptured brain or heart aneurysm requiring emergency surgery, an angiogram can determine the exact area that requires repair. Under local anesthetic, a catheter is placed into a blood vessel in the thigh and the catheter is then threaded through to the appropriate part of the body.
The doctor adds a dye, which helps to locate the heart or brain region that needs treatment.
Outlook
A person can live with, and not know, an unbroken aneurysm. This can be life-threatening though if it bursts.
It can lead to:
- hemorrhagic stroke
- hydrocephalus
- coma
- vasospasm
- long- or short-term brain damage
Vasospasm is the leading cause of disability or death after burst aneurysm.
Factors impacting the chance of full recovery include the nature and severity of the aneurysm, the person’s general health prior to rupture and how rapidly they undergo treatment.
Approximately 40 percent of ruptured aneurysm cases will be fatal within the first 24 hours. Complications can be fatal within 6 months in up to 25 per cent of cases.
Prevention
This is not always possible to avoid an aneurysm, as some are congenital, meaning they are present from birth.
Some lifestyle decisions, however, can affect the risk:
Smoking is a risk factor for both aortic aneurysms and an aneurysm rupture anywhere in the body. Quitting smoking will lower the risk of severe aneurysm.
Managing blood pressure can reduce the risk of an aneurysm too. You can maintain good blood pressure through dietary changes, daily exercise, and medication.
Obesity: may place extra pressure on the heart so it is necessary to take these measures to reduce stress on the walls of the artery.
A balanced diet, Cholesterol can also be reduced and atherosclerosis risk reduced. Fusiform aneurysms also correlate with atherosclerosis.
Someone who has an aneurysm diagnosed and recommended a conservative care plan should consult with a health professional to correct any risk factors.
