An aortic aneurysm is usually silent until it bursts, which is why screening matters
The body's largest artery can quietly balloon to over one and a half times its normal width without causing a single symptom. The first sign is often a rupture, with sudden agonising pain in the belly and back. Up to 81 percent of people whose abdominal aneurysm ruptures die from it.
An aortic aneurysm is a widening of the aorta beyond 1.5 times its usual size, caused by a weakened wall. Some are triggered by trauma, infection or inflammatory disease, but most trace to a defect in the elastin and collagen that give the vessel its strength. An initial injury sets off inflammation, and enzymes chew through the proteins of the wall. Genetics plays a strong role, most obviously in connective tissue conditions such as Marfan and Ehlers-Danlos syndromes. Known risk factors include smoking, heavy drinking, age, high blood pressure, unhealthy cholesterol and coronary disease.
Most occur in the abdomen, where two anatomical quirks leave the artery vulnerable: the wall there carries less elastin, its main load-bearing protein, and lacks the tiny vessels that nourish the chest portion. Men are about four times as likely as women to develop one at any age, and diagnosis usually comes at 65 to 70. An aneurysm cannot be found by physical examination alone, although a large one may show up as a pulsing lump above the navel. Swellings in the aortic arch can stretch a nerve that loops around it, leaving the voice hoarse.
Size largely determines danger. Around 5 cm, the yearly chance of rupture for a typical patient may outweigh the risks of repair, and short bulging saccular aneurysms are more rupture-prone than long fusiform ones. Rupture brings massive internal bleeding; one review found 32 percent of victims die before reaching hospital, and weekend admissions fare worse than weekday ones, probably because of surgical delays.
Surgery, either open or through the blood vessels, is the definitive treatment, while smaller aneurysms are watched with ultrasound every 6 or 12 months. Abdominal ultrasound is the most cost-efficient screening test, and US Medicare now pays for one scan in smokers aged 65 or older. About 170,000 people worldwide died of ruptures in 2019.
Source: Aortic aneurysm
