An aneurysm is initially small, grows slowly and therefore goes unnoticed for a long time. Vascular dilatation often occurs in an artery in the abdomen, chest or brain. However, it becomes life-threatening if the aneurysm bursts. All about the causes and treatment options for aneurysms.

Overview: What is an aneurysm?

An aneurysm is a widening or bulging of the vessel wall. This loses its elasticity, expands and can eventually tear. Due to the associated bleeding, this is a life-threatening condition. Experts speak of an aneurysm if the affected vessel is at least one and a half times (1.5 times) the normal vessel diameter. Visually, the aneurysm often resembles a balloon, a small sac or a spindle. The word aneurysm comes from the ancient Greek and means “widening”.

In principle, aneurysms can occur in any part of the body. However, the most common site of the vascular protrusion is the arteries (arteries). The reason is that they are exposed to greater pressure than the veins. The abdominal aorta is most frequently affected, followed by the thoracic aorta, the cerebral arteries and the knee artery. Men aged 65 and over in particular have an increased risk of an abdominal aortic aneurysm. An aneurysm can be congenital or acquired in the course of life.

Cardiovascular diseases are usually the cause of the weak point in the vessel wall. These include the widespread diseases of high blood pressure and arteriosclerosis. In addition, injuries can also lead to an aneurysm.

The aneurysm is treacherous because it does not cause any symptoms for a long time. As a result, many do not realize the imminent danger posed by an aneurysm. In many cases, we discover the vascular dilatation by chance during another examination or – in the worst case – when the aneurysm bursts. The bleeding is life-threatening and immediate action must be taken.

Aneurysm: causes are often cardiovascular diseases

An aneurysm can have various causes. Some people have it from birth, and hereditary factors can also play a role here. Aneurysms occur far more frequently in the course of life. Cardiovascular diseases such as arteriosclerosis are often the cause. Some factors damage the blood vessels, for example:

  • Age: The fact that the vascular walls lose their elasticity with increasing age is a normal ageing process – you cannot influence this.
  • Smoking not only damages the lungs, but all blood vessels.
  • Overweight: Too many kilos also damage the blood vessels.
  • High blood pressure: Excessive pressure in the blood vessels strains and weakens the walls.
  • High-fat diet
  • Elevated blood lipids (cholesterol)

In addition to the causes mentioned above, the following triggers for aneurysms are possible:

  • Injuries to the vessel wall play a role, for example due to accidents or medical interventions.
  • Some hereditary diseases are also linked to the formation of an aneurysm. Examples include polycystic kidney disease, Marfan syndrome and Ehlers-Danlos syndrome – in the latter two diseases, the connective tissue is weakened.
  • Infections, for example syphilis or Lyme disease
  • Drug use, for example cocaine

Symptoms: an aneurysm often goes unnoticed for a long time

An aneurysm is usually small at first, grows slowly and initially causes no symptoms. Most people feel healthy and the aneurysm therefore remains undetected for a long time in many cases. We often find the vasodilatation by chance, for example during an X-ray examination. Only when the aneurysm becomes larger and presses on surrounding organs and tissue do symptoms appear. These in turn depend on where the aneurysm has formed. This is already considered an emergency and should be clarified immediately in hospital.

  • Aneurysm of the abdominal aorta: Symptoms may include abdominal and/or back pain. Some people also experience a pulsating sensation near the navel with an abdominal aortic aneurysm.
  • Aneurysm of the knee joint artery (popliteal artery aneurysm): In contrast to the abdominal aorta, the popliteal artery aneurysm rarely threatens to rupture. More frequently, clot formation leads to acute occlusion of the knee artery and the associated severe circulatory disorder of the leg. Severe pain and coldness develop in the lower leg and foot, which, if left untreated, can lead to loss of the lower leg if the circulatory disorder persists.
  • Aneurysm in the chest area: It can cause symptoms such as pain in the chest region, back pain, difficulty swallowing, coughing, hoarseness and breathing problems.
  • Aneurysm in the brain: An aneurysm in the head can press on the surrounding nerves and cause various symptoms. Possible symptoms include headaches, visual disturbances, pain in the eye area, facial paralysis, speech disorders or problems with balance. In rare cases, a blood clot (thrombosis) forms inside the aneurysm, which breaks loose and blocks another vessel – resulting in a stroke.

Rupture of the aneurysm – symptoms

The symptoms of an aneurysm rupture depend on the region in which it is located – whether in the brain, chest or abdomen. If the aneurysm bursts, internal bleeding sets in, putting those affected in a life-threatening situation. Action must therefore be taken quickly.

  • In the case of a burst abdominal/thoracic aortic aneurysm, patients complain of a sudden onset of severe abdominal or back pain. These radiate into the groin region.
  • Other symptoms of bleeding include dizziness and unconsciousness or even circulatory collapse.
  • In the case of a brain aneurysm, an extremely severe pain is usually felt at the back of the head or neck. It can also radiate into the back. Many patients vomit or pass out immediately. The leaked blood puts increasing pressure on the brain tissue and damages it. Approximately one third of those affected die when a brain aneurysm bleeds.

Diagnosis of aneurysm

We often find the aneurysm by chance during an examination that we carry out for a completely different reason. The abnormal bulge in the vessel wall can be diagnosed using various imaging techniques. These include, for example, ultrasound (sonography), computer tomography (CT) or magnetic resonance imaging (MRI = magnetic resonance imaging). The size and position of the aneurysm can be clearly seen on the images.

The aneurysm is rarely diagnosed until it has ruptured or thrombosed (blocked by a clot) – in this case you must seek treatment from us immediately, as internal bleeding or reduced blood flow can be life-threatening. We usually operate on the burst aneurysm immediately or restore the blood supply.

Aneurysm: prevention, early detection, prognosis

Men over the age of 65 have a significantly higher risk of aneurysm of the abdominal aorta than women. In many European countries such as Germany, Italy, the UK and Sweden, screening is available for the early detection of abdominal aortic aneurysms. We use ultrasound examinations, the costs of which are covered by health insurance. In Switzerland, however, ultrasound for early detection is only recommended for people at risk (e.g. smokers) aged 65 and over. And: You have to pay for the examination yourself.

Prophylactic surgery can reduce the risk of a rupture of the abdominal aorta and thus the risk of bleeding. However, the treatment also involves risks and can lead to complications. You should therefore always weigh up the pros and cons of surgery with us. This is because not every abdominal aortic aneurysm necessarily bursts. The maximum diameter of the aneurysm is decisive for the prognosis and risk assessment. At a size of 5.5 centimeters for men and 5 centimeters for women, the risk of a rupture increases.

Brain aneurysms are often discovered by chance during CT or MRI examinations of the head. Here, too, there are guidelines as to when treatment is necessary or not. At the USZ, randomly diagnosed aneurysms are assessed by a group of specialists from different disciplines (neurosurgery, neurology and neuroradiology) and a decision is made as to whether treatment is necessary.

Preventing aneurysms – some tips

Two diseases play a special role in aneurysms: vascular calcification (arteriosclerosis) and high blood pressure (hypertension). You can prevent both diseases to a certain extent by maintaining a healthy lifestyle. Even if you already suffer from high blood pressure or high blood lipids, a healthy lifestyle often achieves success. This is best achieved with the following measures:

  • Do not smoke and if you do smoke: Try to stop smoking. You may have to try several times before you successfully quit smoking.
  • Maintain a healthy body weight and avoid being overweight or obese. If you are overweight, try to lose a few kilos. The best recipe for this is a combination of a healthy diet and plenty of exercise.
  • Consume alcohol in moderation or not at all. Take regular alcohol breaks each week.
  • Make sure you get enough exercise in your everyday life (walks, climbing stairs, cycling to work) and take part in sport. Endurance sports such as hiking, swimming, cycling, Nordic walking or cross-country skiing are good. Dancing is also considered very healthy.
  • Eat a healthy diet: consume plenty of fruit, vegetables, pulses and wholegrain products, which contain lots of vitamins, minerals and fiber. Also drink plenty of fluids. It is advisable to drink about 1.5 to two liters per day.

Sometimes these measures are not enough to lower high blood pressure or high blood lipids. In this case, medication can help.

Course and prognosis of an aneurysm

An aneurysm that remains small and does not expand often causes no symptoms and remains undetected for life. However, if it enlarges, the aneurysm can rupture, which can lead to death. The extent, shape and location of the aneurysm can be used to estimate the individual risk.

The prognosis for a ruptured aneurysm is unfavorable and between 30 and 80% (depending on the location) of those affected die. In general, the faster treatment is started, the higher the chances of survival.

Aneurysm: treatment depends on the risk of rupture

Whether we treat an aneurysm depends on how large it is and where in the body it has formed. Another important factor is how high the risk of a crack is. If we have discovered an aneurysm, you should have it checked regularly. If it remains small and does not cause any symptoms, treatment is not necessarily necessary.

If there is a risk of the aneurysm rupturing, surgery is the treatment of choice.