A good resource to understand the procedure, pre and post procedure care: https://mayfieldclinic.com/pe-coiling.htm 

The operator will use the catheter to deliver and place platinum coils in the aneurysm, filling the bulge up to the spot where it arises from the blood vessel. These mesh wires prevent blood flow from entering the aneurysm and thereby reduces the pressure that would otherwise cause it to burst. Most elective patients will spend a night in the hospital and then will go home with minimal restricted activity.

The coils used in this procedure are made of soft platinum metal, and are shaped like a spring. These coils are very small and thin, ranging in size from about twice the width of a human hair (largest) to less than one hair's width (smallest).

Fluoroscopy (a special type of x-ray, similar to an x-ray "movie") aids in this procedure. The catheter, which is inserted into an artery in the groin, is guided by a small wire inside of the catheter along the length of the blood vessel to reach the area of the aneurysm. The physician uses fluoroscopy to guide the catheter to the aneurysm's location in the brain.

When performing a coiling procedure, physicians may utilize additional devices, such as a stent or a balloon, to help keep the coils in place. Balloon remodeling involves temporarily placing a removable balloon adjacent to the aneurysm while coils are positioned in the aneurysm. Occasionally, it is necessary to add more coils at a later time to complete treatment.

https://mayfieldclinic.com/pe-coiling.htm 

Explanations:

https://www.radiologyinfo.org/en/info.cfm?pg=dc-embol

https://www.snisonline.org/aneurysms/