Enovascular abdominal aneurysm repair (EVAR)

Okay, so we're going to talk now a little bit about endovascular aortic repair. Now, this is a technique that was started really in 1991 by an Argentinian surgeon called Juan Perodi and a Russian surgeon as well. And before that, all aortic aneurysm repair was done as a big open operation. This was a minimally invasive approach to try and reduce the trauma to the patients. Fundamentally, as you know, an aortic aneurysm involves a dilation or swelling of the main artery of the body and about 95% of those swellings occur below the levels of the arteries to the kidneys, the renal arteries. In EVAR the aim is to slide a stent graft through the femoral artery at the top of the thigh through a little cut down up into the aorta and then using imaging equipment we can place the stent in exactly the right place below the arteries to the kidneys and when we're in that position we can either unwind the stent or pull a drawstring but the stent graft opens and seals the aneurysm and then we have to bring another stent up into the device to ensure that we've got blood flow going down to both legs. So fundamentally it's a much less invasive way of doing open, of treating aneurysms compared to open surgery. There are some complications, there are some complications that can occur at the time of surgery and those include some bruising and bleeding around the access site. But the biggest set of complications really stretch out over the long term because if there's any leakage of blood between the aortic wall and the stent then you can develop something called an endoleak and the risk of an endoleak is that the aneurysm is still pressurised and can continue to grow over time and for that reason once you've had the EVAR you need to be under careful surveillance and have both ultrasound and CT scans which are spread out over a time interval. We usually do a scan at three months, a scan at six months and then a scan annually and that way we keep an eye on people really throughout the rest of their lives to ensure that the EVAR doesn't migrate and move or develop an endoleak which can cause problems. All in all the operative mortality in other words your chance of dying on the day of surgery from an EVAR is less than 1% and that compares very favorably with open surgery where it's probably more like 3% in UK hospitals although very very low at St. Mary's and Imperial College. So in summary really EVAR is very low morbidity and a very low mortality in the in terms of actually doing the operation but the drawback is it requires long-term surveillance to keep an eye on the stent graft and to make sure that there's no repressurization of the aneurysm sac over time and we can We generally expect about 10% of patients each year will require something else to be done, something small to be done to keep the graft working. But it's a safe technique and it's particularly good for the older age group.