A pilot scheme in Britain will screen older men for aneurysms. Tom O'Dowdexamines its merits
Almost twice as many men die from abdominal aortic aneurysms as do women from cervical cancer. However, we can now do something about such aneurysms.
The aorta is the main artery from the heart down through the chest to the abdomen. It serves people extraordinarily well until later life, when an aneurysm can develop in the abdominal section of the aorta.
An aneurysm is a swelling, or dilatation, of the aorta, which is present mainly in five to 10 per cent of men aged between 65 and 79. It usually does not cause symptoms, but can cause a pulsation in the abdomen, and back and abdominal pain.
The major complication is that it ruptures causing immediate death or, if the patient survives, a surgical emergency. Death rates after rupture are very high, with many dying before reaching hospital and eight out of 10 dying after they get to hospital.
The bigger the aneurysm the more likely it is to rupture. About 2 per cent of aneurysms will rupture if they are less than 4cm in diameter. This rises to 25 per cent in aneurysms which are larger than 5cm in diameter. Clearly, doctors are interested in trying an intervention in those larger aneurysms.
Aortic aneurysms are diagnosed by an ultrasound scan, which is easy and non-invasive. Scanning the aorta is seen as a means of identifying larger aneurysms and reducing the awful mortality from the acute condition by surgical intervention. The argument used by surgeons for years is that elective repair of the aneurysm will reduce rupture and consequent mortality. Operating on a patient in the acute situation leads to poor results, hence the interest in planned surgery.
The operation involves open abdominal surgery to replace the weakened damaged part of the aorta with a synthetic graft, which is an elastic material similar to the healthy aorta.
A review of four good research studies on screening asymptomatic patients for aortic aneurysms is now available on the Cochrane website (free on the Health Research Board website, www.hrb.ie).
The research studies involved the screening of nearly 128,000 men and 9,000 women who were all followed up for three to five years after screening. Those who had been screened underwent aortic repairs when indicated, which contributed to the decline in death rates. The studies showed a significant decrease in mortality in men but not women. The study included death from rupture and from emergency and elective surgery in its analysis.
Arising from this research, the British National Health Service is now planning on offering men reaching their 65th birthday an ultrasound test to check the state of the aorta. The reason is that men of this age will be fit enough to undergo any necessary surgery without undue risk if the aneurysm is more than 5cm in diameter.
It is a major abdominal operation and the post-operative mortality rate is approximately 5-6 per cent in good, experienced centres. This means one in 20 previously asymptomatic men may die from the current surgical operation. There are hopes that developments in less invasive techniques will improve mortality rates.
For men whose aneurysms are less than 5.5cm in diameter, experts recommend regular ultrasound screening with referral for surgery if the aneurysm starts growing more quickly or if it reaches greater than 5cm in diameter.
It is controversial, as people with large aneurysms do not necessarily die from them - many die with them. Doctors have to balance between the risk of rupture and the risk associated with surgery in men who are healthy and without symptoms.
Many healthy people over 65 years will have small aneurysms but will suffer significant anxiety, which may lead them to have unnecessary surgery.
The NHS is going to do the ultrasound through the general practitioner, who will arrange it for men over 65 who agree to it. There will be a pilot scheme in five areas in England, which will offer the screening to 32,000 men.
So what should a man over 65 years do? I was surprised that the evidence for intervention was so strong, but concerned that the post-operative death rates are so high. We do not yet have information on the proportion of men who develop disabling post-operative complications.
The English studies will tell us a lot about the nitty gritty of acceptability, success rates and a return to normal life. The anaesthetists and surgeons will build up expertise, develop slicker interventions, and will have improved outcomes. In the meantime, discuss it with your GP as we will be hearing much more about this condition at our regular education meetings.
• Tom O'Dowdis a practising GP and professor of general practice in Trinity College Dublin