That may be true DaveS but CRNAs are not the only Anesthetist doing "Big Cases" so does AA-Cs examp @ Kennestone in Atlanta,GA you have on staff, 22 Anesthesiologist MDAs 18 Anesthesiologist Assistant(Anesthetist)AAs 1 Certified Register Nurse Anesthetist(CRNAs) The Cardiac Team has on staff 4 Anesthesiologist MDAs 6 Anesthesiologist Assistant(Anesthetist)AAs It's the AA-Cs that are trained to do more complex surgeries like Ruptured Aortic Aneurysm.