Brain Surgeon Brain surgery is a critical and complicated process. The type of brain surgery done depends highly on the condition being treated. For example, a brain aneurysm can be repaired using a catheter that’s introduced into an artery in the groin. If the aneurysm has ruptured, an open surgery called craniotomy may be used. Surgeons, while being as careful and thorough as possible, treat each surgery on a case-by-case basis.