Aneurismen

Aneurismen are localized dilations of a blood vessel caused by weakening of the vessel wall. Although they can occur in veins, aneurysms most often involve arteries, with common sites including the aorta and cerebral arteries. They may be solitary or multiple and can be discovered incidentally or after symptoms appear.

Aneurismen are categorized as true aneurysms, where all three layers of the vessel wall are involved in the dilation, and false or pseudoaneurysms, in which a contained rupture forms a hematoma communicating with the lumen. They can be spherical (saccular) or circumferential (fusiform); some form a separation of wall layers (dissection).

Risk factors include atherosclerosis, hypertension, smoking, and aging, as well as connective tissue disorders such as Marfan or Ehlers-Danlos syndromes. Infections, inflammation, trauma, and congenital vessel abnormalities can also contribute. The specific risk of rupture varies by site, size, growth rate, and patient factors.

Many aneurismen are asymptomatic until they rupture or compress nearby structures. Brain aneurysms may present with a sudden severe headache and neurologic signs; abdominal aortic aneurysms can cause back or abdominal pain or a pulsatile mass. Diagnosis relies on imaging: ultrasound for the abdominal aorta, and computed tomography (CT) or magnetic resonance (MR) angiography, or conventional angiography for other vessels.

Treatment aims to prevent rupture. Small, stable aneurismen are often monitored with periodic imaging. Larger or enlarging aneurismen, or those at high rupture risk, may be treated with open surgical repair or endovascular techniques such as stent grafts; brain aneurysms can be clipped or coiled.

Prevention focuses on risk factor management, including blood pressure control, smoking cessation, lipid management, and targeted screening in high‑risk groups (for example, men aged 65–75 who have smoked for abdominal aortic aneurysm). Prognosis depends on location and rupture risk; rupture requires emergency care with substantial mortality.