 In many places around the world it is customary in to perform the operation under the guidance of a bronchoscope to prevent damage to adjacent structures, high or low position of the tube, and damage to the posterior wall of the trachea and to approve the final position of the tube. However, the use of a bronchoscope depends on the availability of the equipment, knowledge of the operator, temporary occlusion of the trachea and hypercarbia, increased length of the procedure, and maintenance cost disinfection, replacement, etc.. 