Aneurysm – Causes, Symptoms and Treatment

What is an Aneurysm?

An aneurysm is a localized, abnormal widening or bulging of an artery caused by weakness in the arterial wall. The vessel wall balloons outward under the pressure of blood flow. Aneurysms can develop anywhere in the body, but are most commonly found in the aorta (the main artery of the body) and in the arteries of the brain (cerebral aneurysm or intracranial aneurysm). Most aneurysms develop silently over many years without causing symptoms – a rupture transforms them into a medical emergency.

Causes

Aneurysms develop when the wall of an artery becomes weakened. Common causes and risk factors include:

• Atherosclerosis: The most common cause, involving plaque build-up that damages and weakens arterial walls.
• High blood pressure (hypertension): Persistent elevated pressure puts ongoing stress on vessel walls.
• Genetic conditions: Connective tissue disorders such as Marfan syndrome and Ehlers-Danlos syndrome significantly increase risk.
• Smoking: Damages blood vessel walls and accelerates atherosclerosis.
• Infections and inflammation: Rarely, infections can weaken arterial walls (mycotic aneurysm).
• Trauma: Physical injury can cause localized weakening of arterial walls.

Types of Aneurysm

Aneurysms are classified by their location and shape:

• Aortic aneurysm: Affects the aorta, either in the abdomen (abdominal aortic aneurysm, AAA) or the chest (thoracic aortic aneurysm). Abdominal aortic aneurysm is the most common type.
• Cerebral (intracranial) aneurysm: Affects arteries in the brain. Rupture leads to a life-threatening subarachnoid hemorrhage.
• Peripheral aneurysm: Affects other arteries, such as the popliteal artery behind the knee or the renal artery.
• Fusiform aneurysm: The entire circumference of the vessel wall is uniformly dilated.
• Saccular aneurysm: A one-sided, sac-like bulge from the vessel wall – typical of cerebral aneurysms.

Symptoms

Many aneurysms are asymptomatic for years and are discovered incidentally during imaging for other conditions. When symptoms do occur, they depend on the location:

• Abdominal aortic aneurysm: Dull or pulsating abdominal or back pain; a pulsating mass may be felt in the abdomen.
• Thoracic aortic aneurysm: Chest, back or shoulder pain; difficulty swallowing; hoarseness.
• Cerebral aneurysm: Often symptomless until rupture; larger aneurysms may cause headaches, visual disturbances or neurological deficits.
• Ruptured aneurysm: Sudden, extremely severe pain (often described as a thunderclap headache in cerebral rupture), loss of consciousness, and shock – a life-threatening emergency.

Diagnosis

Aneurysms are primarily diagnosed using imaging techniques:

• Ultrasound (sonography): A simple, non-invasive method for detecting abdominal aortic aneurysms – commonly used as a screening tool.
• Computed tomography (CT) with contrast: Provides detailed images of blood vessels; critical when rupture is suspected.
• Magnetic resonance imaging (MRI): Excellent for visualizing vascular changes without radiation exposure.
• Angiography: Direct visualization of blood vessels using contrast dye and X-ray – frequently used for cerebral aneurysms.

Treatment

Treatment depends on the size, location, and growth rate of the aneurysm, as well as the overall health of the patient:

Conservative Management (Watchful Waiting)

Small, asymptomatic aneurysms are typically monitored with regular imaging. Key measures include blood pressure control, smoking cessation, and management of cardiovascular risk factors.

Medical Treatment

Blood pressure-lowering medications (e.g., beta-blockers, ACE inhibitors) can slow aneurysm growth and reduce the risk of rupture.

Surgical Treatment

• Open surgery: The aneurysm is surgically removed and replaced with a vascular graft. Necessary for large or ruptured aneurysms.
• Endovascular repair (EVAR / TEVAR): A stent-graft is inserted minimally invasively through the groin to reinforce the vessel wall from within. Less invasive than open surgery.
• Endovascular coiling (cerebral aneurysms): The aneurysm is filled with small metal coils to prevent blood from entering and triggering a bleed.
• Neurosurgical clipping: A metal clip is placed at the base (neck) of the aneurysm to isolate it from the circulation.

Prevention

Since many aneurysms are linked to modifiable risk factors, the following steps can help reduce the risk:

• Quit smoking or never start
• Monitor and control blood pressure regularly
• Maintain a healthy diet and engage in regular physical activity
• Maintain a healthy body weight
• Attend regular medical check-ups, especially from age 65 onwards

References

1. Chaikof EL et al. - The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. Journal of Vascular Surgery, 2018.
2. Etminan N, Rinkel GJ - Unruptured intracranial aneurysms: development, rupture and preventive management. Nature Reviews Neurology, 2016.
3. World Health Organization (WHO) - Cardiovascular diseases: risk factors and prevention. WHO Technical Report, 2021.