Aneurysms – its causes, symptoms, diagnosis and treatment

At a Glance:

What is an aneurysm?

An aneurysm is a bulging or ballooning of the wall of a blood vessel, usually an artery, due to weakening. A bulge is called an aneurysm when the dilation is at least 50% of the normally expected diameter of the vessel. Aneurysms usually do not cause any symptoms, so a person may remain unaware of their existence, but sudden bursting of the aneurysm can be dangerous.

What are the types of aneurysms?

Aneurysms are either classified by their location in the body or based on their shape. Some of the common locations where aneurysms are observed in the body include:

Aortic aneurysm: This aneurysm is located in the aorta which is the major blood vessel carrying blood from the heart to the other major organs of the body. The aorta measures 2-3 cms in diameter and an aortic aneurysm can bulge to 5cms or more. Within the aorta, aneurysms are commonly seen in some sections that include:

• Abdominal aortic aneurysm (AAA): This aneurysm occurs in the section of the aorta that passes through the abdomen or stomach region. This is the most common aneurysm of the aorta.
• Thoracic aortic aneurysm (TAA): This aneurysm occurs in the section of the aorta that passes through the chest.

Brain or cerebral aneurysm: This aneurysm occurs in the blood vessels supplying blood to the brain.

Peripheral aneurysm: This aneurysm occurs in the blood vessels supplying blood to the other parts of the body, such as legs, groin, or neck. Types of peripheral aneurysm include:

• Carotid artery aneurysm: This aneurysm occurs in an artery called the carotid artery in the neck.
• Femoral artery aneurysm: This aneurysm occurs in an artery called the femoral artery in the groin.
• Mesenteric artery aneurysm: This aneurysm occurs in an artery that transports blood to the intestines.
• Popliteal aneurysm: The most common peripheral aneurysm, this aneurysm happens behind the knee.
• Splenic artery aneurysm: This aneurysm occurs in an artery called splenic artery that supplies blood to the spleen.
• Visceral aneurysm: This aneurysm occurs in the arteries that supply blood to the bowel or kidneys.

Aneurysms are also classified based on the shape of the bulge:

• Fusiform aneurysms: The bulge in this type of an aneurysm is formed on all sides of a blood vessel
• Saccular aneurysms:  The bulge in this type of an aneurysm is formed only on one side of the vessel
• Berry aneurysm: The bulge in this type of an aneurysm looks like a berry on a narrow stem. It is the most common type of brain aneurysm.
• Pseudo aneurysm or false aneurysm: Sometimes a breach in the layers of the vessel wall causes blood to leak within. The leakage gets contained by the surrounding soft tissue or the perivascular tissue of the blood vessel thus creating a pseudo aneurysm. A hole in the vessel wall acts as direct communication of blood flow between the lumen of the aneurysm and that of the vessel. False aneurysms require immediate treatment because the poor support of aneurysm wall from the perivascular tissue poses a higher risk of rupture of a false aneurysm when compared with a true aneurysm of comparable size.

What are the causes of aneurysm?

A characteristic of the aneurysm is the involvement of all three layers of the arterial wall. Even though further research is necessary to confirm why an artery wall weakens to cause an aneurysm, it is believed that the underlying pathology for the formation of an aneurysm could be due to:

• Degradation of the elastic lamellae of the blood vessel
• Accumulation of a leukocytic infiltrate
• Enhanced proteolysis within the wall
• Smooth muscle cell loss within the wall

The conditions which contribute to the above pathology include:

• Atherosclerosis: Accumulation of fat-like substances leads to the formation of plaques within the lining of a blood vessel, causing them to harden and weaken up.
• High blood pressure: A persistently untreated high blood pressure damages and weakens the walls of blood vessels like the aorta.
• Diseases of blood vessels: Certain systemic conditions may cause vasculitis or inflammation of the blood vessels, thereby damaging and weakening of the walls.
• Mycotic or infected aneurysm: Sometimes, the wall of an artery may dilate due to damage by an underlying infection somewhere in the body. Different types of microorganisms, primarily bacteria, can cause an infected aneurysm.

Though less common, sometimes an aneurysm may be present from birth as an arterial defect.

What are the risk factors of aneurysm?

There is some evidence about an unhealthy lifestyle and certain physical characteristics that may contribute to arterial wall weakening and increase a person’s chances of developing an aneurysm, for example:

• Age: Some aneurysms like AAA are likely to occur more often in people of age 65 and older.
• Family history: History of an aneurysm in a first-degree relative increases a person’s risk of having the condition.
• Gender: Men are likely to develop some aneurysms like AAA more often than women, while women are more likely to develop brain aneurysms
• High blood pressure or hypertension
• Obesity
• Poor dietary habits
• Sedentary lifestyle
• Smoking tobacco

What are the symptoms of an aneurysm?

In most of the cases, an aneurysm may be clinically silent i.e it does not present with any symptoms unless it ruptures. However, when present, the symptoms usually depend on the location of the aneurysm.

Abdominal aortic aneurysms (AAA) may be difficult to detect as it is often asymptomatic and slow-growing. In some cases, the aneurysm may never rupture. An enlarging AAA may present with:

• Back pain
• Deep, constant pain in the person’s abdomen or on the side of the abdomen
• Pulsation near the bellybutton

Similarly, due to its effect on nearby nerves and other blood vessels, a TAA can cause symptoms like:

• Breathing difficulties
• Difficulty in swallowing
• Pain in the jaw, chest, and upper back
• Hoarseness of voice
• Persistent cough
• Shortness of breath

In case of an unruptured cerebral aneurysm, symptoms may include:

• Blurred or double vision
• Pain above and behind one eye and a dilated pupil
• Numbness of one side of the face

A ruptured aneurysm may present with:

• Blurred or double vision
• Confusion
• Drooping of eyelid
• Loss of consciousness
• Nausea and vomiting
• Seizure
• Sensitivity to light
• Stiff neck
• Sudden, extremely severe headache

What are the complications of aneurysm?

Aneurysms may give rise to complications due to sudden rupture, disturbance/obstruction to blood flow, and/or clot formation.

Thromboembolism: An aneurysm may pose to be an obstruction to the flow of blood to adjacent tissues and organs. Turbulence in blood flow leads to the formation of blood clots or thrombi that may get disseminated and obstruct smaller blood vessels, and the condition is known as thromboembolism. A thrombus on reaching the brain may obstruct the blood flow to the brain and lead to ischemic stroke or other serious complications.

In most cases, a person with aneurysm does not experience any complications, however, a sudden rupture may cause the following emergency complications:

• Severe pain in the chest or back: Rupture of an aortic aneurysm may cause severe unbearable pain in the chest or back region.
• Angina pectoris: Sometimes an aneurysm can cause angina pain or sudden pain in the chest that can lead to the obliteration of the blood flow to the heart, thereby causing myocardial ischemia or heart attack.
• Subarachnoid hemorrhage (SAH) and stroke: Rupture of an aneurysm in the brain islife-threatening due to the chances of bleeding into the space surrounding the brain. This is manifested by sudden extreme headaches. Emilia Clarke, a famous actor of the west, from the popular TV series Game of Thrones, suffered from complications of two brain aneurysms in February 2011.
• Hydrocephalus: Collection of fluid in the brain
• Coma: A state of prolonged unconsciousness
• Vasospasm: Constriction of blood vessels
• Long- or short-term brain damage

How to diagnose an aneurysm?

In majority cases, aneurysms remain undetected. Doctors usually diagnose aneurysm based on medical history, physical examination, and medical investigations. Sometimes an aneurysm may be detected accidentally during an investigation for some other reason.

Screening for everyone is generally not recommended. However, men between the age group of 65-75 with a history of regular cigarette smoking should consider getting themselves screened in consultation with their physicians.

Investigations:

• MRI Scan: An aneurysm that has not yet ruptured can be evaluated with an MRI if symptoms are present.
• CT Scan: A ruptured aneurysm with the presence of symptoms and the risk of bleeding in the brain is preferred to be evaluated with a CT scan.
• Angiogram: Severe or ruptured aneurysm in the brain or heart requiring emergency surgery, can be evaluated with an angiogram to identify the exact area that requires surgical repair.
• Doppler ultrasound

How to treat an aneurysm?

The goal of treatment — either medical monitoring or surgery — is to prevent your aneurysm from rupturing. Which treatment you have depends on the size of the aortic aneurysm and how fast it’s growing.

Medical monitoring

Your doctor might recommend this option if your abdominal aortic aneurysm is small and you don’t have symptoms. You’ll have regular appointments to check if your aneurysm is growing, and treatment to manage other medical conditions, such as high blood pressure, that could worsen your aneurysm. 

It’s likely you’ll need regular imaging tests to check on the size of your aneurysm. Expect to have an abdominal ultrasound at least six months after your aneurysm is diagnosed and at regular follow-up exams.

For persons with unruptured aneurysms with an insignificant risk of rupture, strategies like smoking cessation and blood pressure control with medications are adopted.

Surgery

Repair is generally recommended if your aneurysm is 1.9 to 2.2 inches (4.8 to 5.6 centimeters) or larger or if it’s growing quickly. Also, your doctor might recommend surgery if you have symptoms such as stomach pain or you have a leaking, tender or painful aneurysm.

Depending on several factors, including location and size of the aneurysm, your age, and other conditions you have, repair options might include:

Open abdominal surgery for AAA: With open surgical repair, the surgeon makes a large cut, or incision, into your abdomen where the aneurysm exists. The area damaged by the aneurysm is then separated surgically from the main part of the aorta and replaced with a synthetic tube (known as an aortic graft), that is sewn into place.

Open surgical repair of an abdominal aortic aneurysm is performed under general anesthesia and takes about 3 to 4 hours. You can expect to spend 3 days in an intensive care unit and remain in the hospital for 7 to 10 days.

Endovascular repair: A less invasive alternative to open surgical repair is endovascular aneurysm repair (EVAR) using a special device called an endovascular stent graft. The stent graft is placed inside the damaged area of the aorta to separate the aneurysm from the normal blood flow. It is designed to be placed without surgically opening the aorta.

Because endovascular aneurysm repair is less invasive than open surgery, you can expect your hospital stay to be shorter – typically as short as 2 to 4 days.

Endovascular surgery isn’t an option for about 30 percent of people with an aneurysm. After endovascular surgery, you’ll need regular imaging tests to ensure that the repair isn’t leaking.

Long-term survival rates are similar for both endovascular surgery and open surgery.

Emergency surgery for ruputred aneurysms:  An emergency surgery may be required in case of a ruptured aneurysms. Surgery may also be recommended in case of a substantial risk of rupture. The risk of a subarachnoid hemorrhage and brain damage is quite high in the case of aneurysm rupture.

Surgical clipping for cerebral aneurysm: An aneurysm is closed off with this surgical procedure. A part of the skull is removed by craniotomy to access the aneurysm and locate the feeding blood vessel of the aneurysm. A metal clip is placed on the neck of the aneurysm to obliterate the flow of the blood.

Endovascular therapy or coiling for cerebral aneurysm: This is a minimally invasive procedure, less invasive than surgical clipping. The affected blood vessel is accessed with a catheter or a hollow tube that is inserted through a small incision in the groin. A guidewire is then passed through the catheter to push a soft platinum wire into the aneurysm. The blood flow to the aneurysm is cut off by coiling the wire around the base where the artery supplies blood to the aneurysm.

Flow diverters for aneurysms in brain: These are newer treatment options for a brain aneurysm, especially the larger ones which are not amenable to other forms of treatment. Flow diverters are tubular stent-like implants that act by diverting the blood flow away from the sac of an aneurysm. Once the blood movement within the aneurysm stops, the body is stimulated to heal the site and reconstruction of the parent artery is encouraged.

Treatment options for peripheral aneurysms are similar to aortic aneurysm, common treatment options for a peripheral aneurysm also include:

• Continued observation for small aneurysm
• Conventional surgical repair (usually a bypass)
• Endovascular repair

What is the prognosis of aneurysms?

The prognosis or likely outcome of an aneurysm is dependent on certain factors like:

• The type of aneurysm
• The extent of the aneurysm
• The underlying health of the person
• Timeframe within which treatment is received

It is estimated that within 24 hours of rupture of the brain aneurysm, 40% of cases are fatal. A resulting neurological impairment or disability is experienced in nearly 66% of those who survive.

Aortic aneurysms, especially the AAA can rapidly become fatal.

• Without surgery, the annual survival rate is 20% for an AAA of over 6 cm
• In persons who survive the transfer to a hospital in an emergency, the overall survival is 50%.
• Nearly 25% of aortic aneurysms are thoracic aortic aneurysms (TAA).
• In persons with TAA, the survival rate without treatment is 56 %  and 85 % after the surgery. 

How to prevent an aneurysm?

Focusing on heart health can prevent an AAA. This means watching what you eat, exercising, and avoiding other cardiovascular risk factors such as smoking. Your doctor might also prescribe medicines to treat high blood pressure or cholesterol or to help you control your diabetes.

Your doctor may want to screen you for an AAA when you turn 65 if you’re at a higher risk due to smoking and other factors. The screening test uses an abdominal ultrasound to scan your aorta for bulges. It’s painless and only needs to be performed once.

Conclusion:

The carpal tunnel syndrome is a common medical condition that affects the hand and wrist of a person. Compression or injury of the median nerve is the underlying pathology that causes the syndrome. Individuals who smoke or those with medical conditions like rheumatoid arthritis, diabetes, hypothyroidism are prone to developing carpal tunnel syndrome.

The most common presenting symptoms of carpal tunnel syndrome are numbness, paraesthesia, and pain in the affected area that may also be associated with a decrease in hand function at times.

The treatment for carpal tunnel syndrome includes non-surgical options and surgical interventions if non-surgical options fail. Prompt treatment can cure carpal tunnel syndrome completely.

In the endoscopic carpal tunnel release surgery, the surgeon cuts the transverse carpal ligament using a minimally invasive technique with small incisions under local anesthesia. The procedure does not require hospitalization and is associated with minimal complications and a faster recovery.

Reference

• Mayo Clinic. Brain Aneurysm. Available at:  org/diseases-conditions/brain-aneurysm/symptoms-causes/syc-20361483. Accessed on January 05, 2020
• Mayo Clinic. Abdominal aortic aneurysm. Available at:  https://www.mayoclinic.org/diseases-conditions/abdominal-aortic-aneurysm/symptoms-causes/syc-20350688Accessed on January 05, 2020
• Mayo Clinic. Thoracic aortic aneurysm. Available at:  https://www.mayoclinic.org/diseases-conditions/thoracic-aortic-aneurysm/symptoms-causes/syc-20350188. Accessed on January 05, 2020
• National Heart, Lung and Blood Institute. Aortic Aneurysm. Available at:  https://www.nhlbi.nih.gov/health-topics/aneurysm. Accessed on January 05, 2020