How are AAAs diagnosed?
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Many people discover their aneurysms incidentally when getting imaging studies for other illnesses. Because aneurysms cause no symptoms, but have such grave consequences, clinicians look for them in high-risk groups. Screening and appropriate treatment are crucial to early identification and prevention of the complications of aortic aneurysm.
If you feel you might be at risk for aneurysm, the first step is to talk to your GP. Upon physical examination, a physician may feel a pulsating mass in the upper abdomen. Imaging tests can aid in the detection and surveillance of abdominal aortic aneurysms (AAAs). An abdominal ultrasound can confirm the presence of an aneurysm and provide information about the location and dimensions of the aorta.
CTA (computed tomographic angiography) is considered the ‘gold standard’ for imaging the entire aorta. CTA is a special type of CAT scan that is performed with intravenous contrast, or dye, and can provide detailed information about the anatomic location of the aneurysm and its exact size. Physicians are also very interested in what branches of the aorta, including kidney or gut arteries, may be involved. Computer modeling software is used to help interpret the CTA scan and can aid physicians in fully understanding the complexity of the aneurysm.
NHS Abdominal Aortic Aneurysm programme
The NHS Abdominal Aortic Aneurysm programme recommend a screening ultrasound for certain people at risk of AAA. AAA screening is offered to all men registered with a GP during the year they turn 65.
Several studies have been done to determine when to operate on aneurysms. Because the surgery is relatively high risk, the evidence suggests that waiting until an AAA is 5-5.5cm is the most appropriate time to consider intervention. In more complex aneurysms, such as those involving the thoracic (chest) or thoracoabdominal (chest and abdomen) aorta, many physicians would wait until the aneurysm is >6cm before considering intervention because the surgery poses an even higher risk. In small aneurysms, the risk to the patient outweighs the benefit of surgical intervention. Patients with small AAAs need to be closely monitored by a vascular specialist and the aneurysm needs to be re-imaged over time with ultrasound or CTA studies to monitor for growth. Because aneurysm disease often occurs in patients who also have heart or lung disease, the risks of surgery include heart and lung complications.
Top image: An unrepaired abdominal aortic aneurysm (AAA). Computed tomographic angiography (CTA): 3-dimensional (3D) reconstruction of an unrepaired AAA measuring 5.2 cm. 3D reconstructions are helpful for planning AAA repair. Courtesy of Vascular Medicine 2014, vol. 19(5) 421-424 (authors: Laurie Ann Moennich and Tara M Mastracci)
Bottom image: Endovascular repair of an abdominal aortic aneurysm (AAA). Computed tomographic angiography (CTA): 3-dimensional reconstruction of an endovascular AAA. Following endovascular repair, patients have annual CT imaging to ensure the stability and overall effectiveness of the implanted device. Courtesy of Vascular Medicine 2014, vol. 19(5) 421-424 (authors: Laurie Ann Moennich and Tara M Mastracci)