- An aortic aneurysm is a pathological dilation of the aorta, the body’s largest artery, in which the vessel wall weakens and bulges outward. By definition, an aortic aneurysm is present when the aortic diameter expands to at least 1.5 times its normal size.
- This condition is dangerous because aneurysms often enlarge silently over time and may rupture or dissect, leading to life-threatening internal bleeding. Aneurysms can occur in any segment of the aorta, but they are most commonly classified into two major types: abdominal aortic aneurysms (AAA), typically located below the renal arteries, and thoracic aortic aneurysms (TAA), occurring in the chest portion of the aorta.
- The pathogenesis of aortic aneurysms is multifactorial and involves structural weakening of the aortic wall. Normally, the aortic wall is composed of elastin, collagen, and smooth muscle cells that provide strength and elasticity. In aneurysm formation, these components are degraded or altered due to chronic inflammation, oxidative stress, and imbalance between proteolytic enzymes (such as matrix metalloproteinases) and their inhibitors. Risk factors such as atherosclerosis, smoking, hypertension, advanced age, male sex, and genetic predisposition contribute significantly. Certain connective tissue disorders, including Marfan syndrome, Loeys-Dietz syndrome, and Ehlers-Danlos syndrome, are strongly linked to thoracic aneurysms due to inherent defects in the structural proteins of the aortic wall.
- Clinical presentation varies widely. Many aortic aneurysms are asymptomatic and are detected incidentally during imaging studies performed for unrelated reasons. When symptoms occur, they may include abdominal or back pain (in AAA) or chest and upper back pain (in TAA), depending on the location and size. A pulsating mass in the abdomen is a classic finding in some cases of large AAA. The most feared complications are rupture, which presents with sudden severe pain, hypotension, and shock, and aortic dissection, where blood enters and splits the layers of the vessel wall. Both conditions carry extremely high mortality rates if not treated promptly.
- Diagnosis is established through imaging techniques. Ultrasound is the preferred method for screening and surveillance of abdominal aneurysms because it is safe, inexpensive, and highly accurate. CT angiography (CTA) and magnetic resonance angiography (MRA) provide more detailed information, especially for surgical planning, by assessing aneurysm size, shape, and involvement of branch vessels. Guidelines often recommend routine screening for AAA in men aged 65–75 years who have a history of smoking, as this population is at the highest risk.
- Management of aortic aneurysms depends on their size, growth rate, location, and the patient’s overall health. Small aneurysms are usually monitored with periodic imaging and managed with risk factor modification, including strict blood pressure control, smoking cessation, and statin therapy. Large or rapidly expanding aneurysms generally require surgical intervention to prevent rupture. Two main approaches are used: open surgical repair, which involves replacing the weakened section of the aorta with a graft, and endovascular aneurysm repair (EVAR/TEVAR), a less invasive technique where a stent-graft is inserted through the arteries to reinforce the aneurysm from within. EVAR has lower perioperative risks but requires lifelong monitoring for potential complications such as endoleaks.
- Prognosis is highly dependent on early detection and appropriate management. Small aneurysms may remain stable for years, but once rupture occurs, mortality rates are extremely high, often exceeding 80%. Preventive strategies, including screening programs, lifestyle modification, and control of cardiovascular risk factors, are critical in reducing the burden of this disease.
