I had one of these
http://www.fda.gov/MedicalDevices/Pr.../ucm252130.htm
placed across my 8cm necked aneurysm the location made it very dangerous to coil or clip. the recovery was amazing. i felt like i could have gone home that afternoon but of course i didn't for observation purposes.
i had an MRI 6 months later and the aneurysm did not sure up on it
i think there is a lot of peace of mind in getting your aneurysm treated. If I had not had it treated I would have panicked every time i got a headache.