Abdominal Aortic Aneurysm (AAA) is a dangerous swelling of the abdominal aorta which has an increased chance of rupture if it is larger than 5.5cm--a majority of people die from ruptures. The cause of AAA is complex, including atherosclerosis,smoking, and a genetic predisposition.
Surgeons have perfected a new method for treating AAA's over the past decade, called endovascular repair, or EVAR. In this procedure, 2 small incisions are made in the groin, and a graft is passed through the arteries under Xray control and fixed with a stent which holds the graft in place; this procedure is much less invasive than conventional surgery which requires a deep abdominal incision.
41 UK hospitals collaborated in the study, providing a surgical and radiological team to investigate whether EVAR is as good or better than conventional open surgery. More than 1000 patients with large (5.5 cm or greater) AAA (all of whom were over 60 years of age, and over 90% of whom were men) were randomly allocated to receive either EVAR or conventional open surgery. The death rate within 30 days of surgery was reduced by around two-thirds compared with patients given open surgery (1.7% and 4.7% mortality rates, respectively); however, there were 75% more secondary procedures done among patients initially given EVAR.
Investigator Roger Greenhalgh (Imperial College London, and Hammersmith Hospitals NHS Trust, UK) comments: "These early results with EVAR, applied to large aneurysms in suitable patients, provide justification for continued use of this technique in controlled or trial settings; however, the early promise of endovascular repair cannot be guaranteed and might not endure in the long term. These 30-day mortality results are a licence to continue scientific evaluation of EVAR, but not to change clinical practice. He adds: "The NHS is the perfect vehicle to do research of this type, but it is entirely dependent on the determination of a group of doctors--as in this case--to overcome clinical uncertainty to be able to offer their patients the best possible treatment."
Contact: Professor R M Greenhalgh, c/o Tony Stephenson, Imperial College London Press Office; T) 44-20-7594-6712 or 44-7753-739766 ; r.greenhalgh@imperial.ac.uk
Journal
The Lancet