Affiliation: | 1. Department of Cardiothoracic Surgery, Mazandaran University of Medical Sciences, , Sari, Iran;2. The National Centre for Airway Reconstruction, Department of Otolaryngology, Charing Cross Hospital, , London, United Kingdom;3. Department of Anaesthesia, University College Hospitals NHS Trust, , London, United Kingdom;4. Postgraduate Medical Institute, Anglia Ruskin University, , Chelmsford, United Kingdom |