Abdominal Aortic Aneurysm

Case study: 'I was lucky it was Boxing Day. There was less traffic and the ambulance was able to get to the hospital more quickly.'

Information on other heart diseases here.

What is it?

AAA is a disease that occurs when the walls of the aorta, the body's largest blood vessel, weaken and expand. The larger the aneurysm, the more apt it is to rupture, creating a potentially fatal situation — only two in ten survive, with most dying before they reach a hospital. Whilst one in 10 men over 65 may have some enlargement of the abdominal aorta, about 1 in 100 are at risk of rupture — and so require surgery.

What's the risk?

In England and Wales, between 6,000 and 10,000 people each year suffer from rupture (bursting) of an abdominal aortic aneurysm. The vast majority of these patients are men over the age of 65 years.

Those over sixty, especially those who smoke, have high blood pressure, angina or other heart related diseases, or who have a family history of the disease, are at a higher than average risk of an aneurysm, the most common of which is an abdominal aortic aneurysm or AAA. It's not purely a male disease - women may also suffer - but men are five times more likely to have it.

What causes it?

The exact cause of AAAs is unknown, and in its early stages, the aneurysm often is virtually pain-free and may present few recognizable symptoms. Occasionally, a patient may become aware of a feeling of pulsation in the abdomen. On rare occasions, a lump can be visible. A doctor is the best person to diagnose one, so those with specific AAA questions or concerns should contact their GP. The good news is that, when diagnosed early, AAA often can be treated, or even cured.

The UK's National Screening Committee has recently decided that AAA screening could be offered to men aged 65. In tandem with this, it has issued a number of provisos to ensure that clear information is given to those invited to screening, and correct support provided to vascular surgeons, allowing them to specialize in the area. Guidance on the screening is due before the end of 2006.

More information on the screening discussions here.

Should I see a doctor?

It's clear that AAA is a serious disease, which, if undetected and untreated, could prove to be life-threatening. Today, the growing use of a new treatment (EVAR — see below) is helping spur a rising survival rate of AAA patients. With an ever-increasing elderly population, those who feel they may be at risk should consult their GPs.

How does screening work?

The preferred method of screening is by a painless ultrasound scan or CAT scan. These are simple exams - they are non-invasive and can be done on an outpatient basis. The scan will tell doctors how big the aneurysm is — the key element in determining whether or not treatment is needed.

What is the treatment?

Until recently, open surgery had been the most common form of repairing AAAs. Whilst this is successful, it does carry certain risks. Open surgery involves a major operation, with a long recovery time that the elderly may often struggle to tolerate. The alternative, Endovascular Aortic Repair (EVAR), provides a less-invasive alternative to open surgery, and was first introduced to vascular surgeons in 1999. Barry Thomas, who is director of the Endovascular Therapy Products Division for Cook Incorporated who make the devices used in EVAR says: 'this minimally invasive procedure has since increased dramatically, helping patients with severe aneurysms have a better chance to live a longer, fuller life.'

EVAR is performed by making two small incisions in the groin and threading two catheters through the patient's arteries. Once in place, the catheters are used by the physician to release a tubular device comprised of large z-shaped metal stents sewn to surgical graft material that expands to channel blood through the aorta and reduce the pressure on the aneurismal sac. The recovery time for endovascular repair is usually much shorter than with open surgery, cutting hospital stays down to two to three days.

A recent study published in The Lancet in August 2005 which investigated a thousand AAA patients at 41 hospitals, showed that EVAR boosted the odds for short—term patient survival (ie. within 30 days) by two-thirds when compared to standard surgery.

Thomas also cites a March 2006 survey from the US published in the Journal of Vascular Surgery which compared the survival rates of AAA patients. 'The three-year, 28,000-person study, which was conducted at the University of Pittsburgh, revealed that the risk of in-hospital death was significantly lower with EVAR.'