In order to provide anatomical basis for prevention of the arteria anonyma hemorrhaging after tracheotomy,a study was conducted based on dissection in 7 adult cadvers and 17 sets of cross sections of cadvers.The relations of arteria anonyma and trachea were observed and measured.The position of arteria anonyma is close to the height from 8th to 12th tracheal cartilagines.It is just 3.5mm that the shortest thickness from artery's inner wall to trachea's.Based on the anatomical structure,the relation between ...