Biobased.
My suggestion to you is that you get a good neurologist, neurosurgeon and a interventional neurologist. Have input from these doctors.

Being diagnosed with a non reptured aneurysm is something one must take serious, and it needs attention. You should not delay this. In a way you are lucky that this was found incidentally. Sometimes, and very often actually, people do not know they have an aneurysm until it ruptures, and the survival rate is MUCH lower in this cases, depending how quickly one reach the hospital and get emergency surgery to stop the bleeding and repair the aneurysm.---So consider yourself lucky to have found this.

A ruptured aneurysm is a life thretening medical emergency.
( and there is no telling when it can rupture, and then causing a bleeding into your brain)
The symptoms of a ruptured aneurysm is an excruciating headache, the worst one has ever had. ( Many people die) if not treated very quickly.

The best practice of treating ( rule) of aneurysms, is that it should be repaired if it is 6 mm or grater. If it is less, sometimes neurologists decide to monitor the aneurysm closely with MRI and Cerebral Angiogram on a regular time intervals. They then look for enlargement of the size of the aneurysm.

A Cerebral Angiogram is a procedure when the doctor insert a catheter into a large blood vessel in the groin, thread it up into your brain. There is injection of contrast dye. The procedure is monitored on a big screen. The pictures taken will help the doctor locate and measure the exact cite and seize of the aneurysm. This is done prior to the repair of the aneurysm.

I had an aneurysm noted on a MRI done due to visual disturbance and headache. They found a 6 mm aneurysm close to the optic nerve.
I decided to have this fixed right away, and had procedure done within a few days
I had it repaired by Endovascular embolization and stent placement.
Meaning I had coils placed inside the aneurysm, and a stent in the bloodvessel by the aneurysm.

This is the procedure that is being used much these days. What actually happens, is that the coils fills up the aneurysm, then as, time goes by, the body responds is that there will be growth of new endothelial cells filling up the aneurysm. The stent assist to close the opening into the aneurysm from the vessel.

I had to be monitored with new Cerebral Angiogram every 6 months for 1 year.
I was put on Aspirin 81 mg( small dose) and Plavix to prevent a cloth forming in the area .
Yes, the Aspirin treatment will be for life, but that is realy something that is a good prevention in general of both heart attack and stroke. The Plavix is usually for some months( until the aneurysm has stabilized and there is less chance of a cloth to form along the stent(causing a stroke). Some doctors gives this med for longer periods.
In my case, the Plavix was stopped after 6 months, and about a week after that I had a tiny little cloth forming, causing a small stroke. The Plavix was then restarted, and I will be on it for lifetime. My doctor and I decided on that.

So, I suggest you get some good neurologists. I would not leave an aneurysm untreated if you were so lucky as to find one.

Best of luck.