Hi,
I read a few studies on mortality rates a couple a years ago, and it landed at around 2% (<30 days) for this kind of surgery. Remember however that this includes older population and those with symptoms as well, so it will be lower for young/healthy people. I understood it to be about half/half on the table or through complications.
There is (obviously...) no concept of stable aneuyrisms, at least not when it is larger in size. I had 5,1 cm 15 years ago, and were pretty stable for 10 years at 5,3 cm. I also had absolutely no symptoms and were running long distance. In fact, I was stupid enough to gather old MRI data to convince the doctors to postpone my surgery, since I was stable and had too much to do at work.
This was not very smart.
I dissected 1 1/2 years ago, still at 5,3 cm. I had had light fever for a few days without any other symptoms and got light angina one morning. It felt wrong somehow, so I went to the ER. Despite my history I was initially treated as any other infarction patient with chest pain, and it took 5 hours before I managed to push through the contrast CT queue when the pain was increasing. Then everything went extremely fast. I was rushed in ambulance to a nearby hospital and on the table within in 20 minutes from leaving the first hospital. At the table, the dissection was quite advanced, and blood leaking through a tear which I understand was more to the heart side, which might have saved me. I later had complications with blood clot formation (which is common especially after dissections), but another OHS saved me from a relatively certain stroke. I was also lucky to have one of Sweden's top surgeons, despite this being a Sunday afternoon.
My family was told that I would have a fair chance to survive when I left for surgery, which was a bit of a white lie.
So much for stable aneuyrisms.
All planned surgeries are astronomically more safe than the ones done during dissections. So do it if they say you should.
As you can see on this forum, the outcome differs a lot between the surgeries. Most can get back to something akin to what they did before, but not everyone. I can still run, but much shorter distances. I hope this will get better after my last surgery (aorta dilation), but typically the emergency surgeries seem to be more likely to render less optimal results. I am however very grateful for being alive.
::g