The Montgomery tracheal cannula: radiological assessment.

The Montgomery silicone tracheal cannula is a relatively new tracheal airway device used in specific clinical situations including obstructive sleep-apnea in place of a conventional tracheostomy tube. The position of the cannula was evaluated in four patients by conventional or xeroradiographic lateral views of the neck. Improper positioning resulting in respiratory difficulty was detected in one patient. Lateral tomography was found to be helpful in visualizing the cannula in an obese patient.