Hello Xmarianne,
welcome to braintalk, I dont know about a basil apex aneurysm , but my basilar tip aneurysm has such a wide neck that the doctor had to use two stents first to cover it then put the coils in.This was my second surgery and it is very nerve wracking. Like you mine was found during an MRI after I fell and they were looking for a blood clot or seeing if I had any bleeding in the brain.
Mine was estimated at 4mm when found but further testing showed it to be 7mm and tall like a loaf of bread.... then when surgery was done it was alot bigger. I have to have checks to make sure the coils have not compacted or slipped down. I hope you do well and I am sure others will answer you that may have more information for you. I dont know if any of this is helpful to you but I did want to reply to let you know there are people who will reach out to you and offer help any way they can.

ging