When it is recommended for a patient to have brain aneurysm surgery one of the main techniques used is called neurosurgical clipping.

Clipping is done by having a craniotomy, which is an incision in the skin over the head and through the bone.  A clip is then placed across the aneurysm where it extends from the blood vessel.  This cuts off the blood flow to prevent it from entering the aneurysm. After the clip is in place the aneurysm will not grow larger and will begin to shrink.  There is a low risk of regrowth. The clip will remain on the artery permanently. 

Clipping is effective for ruptured and unruptured aneurysms.  Many neurosurgeons perform mini craniotomies or eye brow incisions to clip an aneurysm.  This is where a small incision is made above the eyebrow to clip the aneurysm. This is still considered an invasive procedure.