People with abdominal aortic aneurysms stand a better chance of surviving if they are operated on at hospitals that see large numbers of these patients than if they are treated at smaller regional hospitals with fewer such patients.
This finding is supported by two papers published in this month's BJS. Both pieces of research were led by Peter Holt, who works at St George's Hospital, London.
"Our research adds to the evidence that concentrating surgical resources in large centres of excellence can provide great benefit to patients. A bad outcome in this type of surgery is death, and specialist centres are best placed to prevent it," says Mr Holt.
An aortic aneurysm occurs when the muscle wall of the main artery that runs vertically through the body (the aortic artery) weakens and the artery bulges out irreversibly due to the blood pressure inside pushing out on the weakened segment. The wall can become extremely weak and the resulting bulge very large. If not repaired surgically, it is liable to tear (rupture) and cause catastrophic bleeding, which is fatal in 80% of cases as many patients never make it to a hospital.
The first paper reports an epidemiological study of UK data from 2000 to 2005 that investigated the outcomes of surgery on 112,545 patients. This showed that specialist centres dealing with more than 32 cases a year generate better outcomes than regional centres with lower caseloads. If the patient came in with a ruptured aneurysm the chance of survival was equally low in both regional and specialist centres.
The second paper reports a meta-analysis and systematic review that identified data, mainly from the USA, from 26 separate studies, which together involved over 350,000 patients. Peter Holt and his team concluded that a centre needed to be performing surgery on at least 43 abdominal aortic aneurysms before it could provide significantly greater chances of success. In this study, the benefit was present for non-ruptured and ruptured aneurysms alike.
"We believe that patients should be sent to centres that have a high volume of these cases and a proven track-record of high rates of success," says Holt.
