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Posterior view of a popliteal aneurysm, created from reconstructing computed tomography (CT) scans taken from an 84-year-old man undergoing treatment. The femur, or thigh bone, is shown on the left, with the popliteal artery running down the middle of the image. The aneurysm is shown centre frame, with a reddish-blue appearance and eggshell-like boundary.
What is an aneurysm?
An aneurysm is a swelling of an artery, in this case the popliteal artery, which extends from the lower region of the thigh to the upper region of the calf. It presents itself as a blood-filled, balloon-like bulge of a blood vessel. The exact cause of this condition is unknown, although it is linked to atherosclerosis, or hardening of the arteries. Risk factors for developing aneurysms include diabetes, smoking and high blood pressure. Aneurysms are commonly found in the abdominal vessels (abdominal aortic aneurysms) and leg vessels, as shown here.
How are aneurysms treated?
Unruptured aneurysms are usually asymptomatic, but ruptured abdominal aortic aneurysms carry an overall mortality of over 75 per cent. This drops to below 5 per cent when treated by vascular surgeons. An aneurysm at risk of rupture or occlusion can be treated to divert its blood flow; the average size of a popliteal artery aneurysm suggested for treatment is over 3 cm. The aneurysm in this image is just over 6 cm and has had a stent-graft fitted. Stents are small wire frames supporting both artery and graft, which then divert the flow of blood. This procedure is known as popliteal endovascular aneurysm repair (PEVAR).