An aneurysm is a loss of vascular wall strength which results in separation of the layers that lead to swelling and possibly rupture. High pressure, large arteries cause the greatest risk for sudden exsanguination and death. Of these, the aorta is the largest.
An aneurysm diagnosis is established when the full-thickness dilation of a blood vessel is >50% larger than its normal diameter (2-3 cm). For clinical purposes, aortic aneurysm is recognized to have a diameter > 3 cm. Its risk factors are:
- Male gender
- Family history
- Presence of aneurysms elsewhere
Use of Ultrasound in Aortic Aneurysm
Screening via ultrasound to measure aortic diameter is used in men aged 65-75 who had ever smoked, or (regardless of smoking history) who who have/had a close relative who had required surgical aortic aneurysm repair or who had died from rupture.
Once diagnosed, the stability or progress of an aortic aneurysm can be followed by ultrasound over time, and if there is progression, can indicate the time that surgical intervention is prudent to avert a catastrophic rupture.
Symptoms of Aortic Aneurysm
In the abdomen, aortic aneurysm does not usually cause symptoms unless it is actively expanding, compresses surrounding structures, is inflamed, or ruptures. When present, symptoms include abdominal, back, or flank pain, distention, and hemodynamic changes.
In the thoracic cavity, aortic aneurysm, following the same symptom-causing provocations as with abdominal aneurysms, can result in sudden chest, back, or abdominal pain. Dyspnea can occur if there is compression of the pulmonary trachea or bronchi.
Repair of either abdominal or thoracic aortic aneurysms is indicated with symptomatology or if a critical diameter is breeched which raises the risk of rupture to unacceptable levels.