An aneurysm is a blood-bulge inside the brain. If the wall of a blood vessel gets weak. Kind of like a bubble. It is very dangerous if such a bulge breaks and bleeds into the brain. That will definitely lead to damage - the longer it takes to spot the problem, the more damage it causes.
So, to prevent that from happening, they open the head remove the bulge and close the blood vessel. Of course any operation in the open brain as always risky. The skull must be opened, they must be extremely careful about infections. And it definitely takes a while to heal those OP-wounds.
It just might be that the aneurysm is more dangerous.
Now the big question is: Where in the brain is that aneurysm? Is it close to an important area of the brain? Is it at the surface, near the skull or is it somewhere deeply beneath important nerve tissue? And of course how good is the surgeon who does the surgery?
I believe that only a brain surgeon who looks at the magnetic resonance tomography scans of that patient can really tell you what such an operation would lead to.
I have already had the surgery, so I know about the risks of the actual surgery. I was just kinda wondering about any possible long term issues. The aneurysm was in the center most part of my brain. I have the MRI scans as well as CT scans but when I had the surgery, I was only twelve so I don't recall having heard anything about long term effects.
So you'd better ask your parents or the doctor.
The effects of the surgery will probably be different in every patient. But if you don't have anything now, the surgery itself will probably not cause problems in the future.... if you have weak blood vessels in general, you might have to check whether you develop another aneurysm every other year.