Parts of brain affected

A while ago, congresswoman gifford was shot in the back of her head, on her left side.  The bullet exited as well from the same side.  At first, she was not expected to survive.  However, following a craniotomy and other procedures, her recovery has been called a "miracle".  She has made so much progress that she has returned to congress.  What is a craniotomy? What procedures may have been done? Give some reasons why she was not expected to survive.  Since she is able to talk as well as reume some of her work commitments, what parts of the brain may not have been severely affected?