Surgical improvement of collateral circulation to the brain.
D001775:Blood Circulation; D001921:Brain / Q000098:blood supply*; D002340:Carotid Artery Diseases / Q000601:surgery*; D002560:Cerebrovascular Circulation; D003097:Collateral Circulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D013514:Surgical Procedures, Operative