A swelling in the body's main artery usually gives no warning before it bursts
An abdominal aortic aneurysm is a bulge in the aorta below the chest, wider than 3 cm. Most cause no symptoms at all until they rupture, and a rupture kills 85 to 90 per cent of people it strikes. That silence is why several countries now scan older men routinely.
It is the most common kind of aortic aneurysm, and about 85 per cent form below the kidneys. Men are five times more likely to have one, and they affect 2 to 8 per cent of men over 65. Risk rises with age over 50, family history, high blood pressure and other blood vessel disease, and more than 90 per cent of people who develop one have smoked at some point. Brothers of patients face four to six times the usual risk, and connective tissue disorders such as Marfan syndrome are strongly linked.
The underlying cause is still unclear. Atherosclerosis was long blamed because the walls often carry plaque, but that idea cannot explain the first defect. When an aneurysm does make itself felt, it may cause a pulsing feeling in the belly or pain in the back, chest or legs, and a rupture can be mistaken for kidney stones or a strained back.
Size largely predicts danger. Below 5.5 cm, the chance of rupture in the coming year is under 1 per cent; between 5.5 and 7 cm it is about 10 per cent, and above 7 cm about a third. Ultrasound is the usual screening tool, and CT detects aneurysms with nearly 100 per cent sensitivity. Guidelines typically call for repair once the diameter passes 5.5 cm in men or 5.0 cm in women, or if it grows faster than a centimetre a year. Endovascular repair, known as EVAR, carries lower short-term risk of death than open surgery, though long-term outcomes look similar and repeat procedures are more common.
Screening policies differ. The United States recommends ultrasound for men aged 65 to 75 who have smoked, while Sweden and the United Kingdom screen all men over 65; Sweden's programme is reported to cut deaths from the condition by 42 per cent. Worldwide, the annual toll from aortic aneurysms climbed from 100,000 in 1990 to 168,200 by 2013.
Source: Abdominal aortic aneurysm
