What is the need for follow up or further procedures after aneurysm repair?

I want to ask you in terms of the need for re-intervention and the need for further procedures, how does that stack up in terms of open repair versus endovascular repair? So this is where there's quite a big divergence in how much time people will need to invest and spend in coming back to hospital over the years after their repair. So, for our patients in Imperial, certainly, if they've had an open aortic repair, we will see them once at six weeks for a follow-up appointment, just to say, how are you doing, let's have a look at your incision, make sure that the patient is happy. And then we will ask them to come back five years later for one scan, one CT scan, just make sure the aorta hasn't dilated above the repair and got the rest of the aorta degenerated. For endovascular patients it's very different. So they will need a CT scan at three months, then six months and then either an ultrasound or a CT in one year and thereafter they will come for an ultrasound of their aorta repair every year, at least once a year. So they're really stuck into a long-term program of surveillance and the reason we have to do that is because we know that stent grafts don't last forever and that they can spring these things called endoligs which can be addressed very successfully if we know they're happening. If we don't know the endoligs there it can even lead to something as bad as rupture of the aneurysm so it's not something that can be ignored and really hand in glove with that is that For patients who've had an endovascular repair, there's about a 5-10% risk every year that they will need something doing to touch up the repair. It might be a balloon dilatation, it might be an extension of the stent graft, either a little bit higher or a little bit lower, but they will need these things to be done in order to maintain the complete complete exclusion of blood flow from the aneurysm and so there's not just the fact they have to come back for regular surveillance but they also have to come back for occasionally for intervention and again you can predict which ones are more likely to need intervention and that's the patients who haven't got good aortic anesthesia from the very outset.