1 National Hospital Organization Osaka National Hospital, Department of Otorhinolaryngology, Osaka, Japan.
2 National Hospital Organization Osaka National Hospital, Department of Otorhinolaryngology, Osaka, Japan; Osaka University Graduate School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, Osaka, Japan. Electronic address: ttsuda@ent.med.osaka-u.ac.jp.
3 National Hospital Organization Osaka National Hospital, Department of Otorhinolaryngology, Osaka, Japan; Osaka University Graduate School of Medicine, Department of Otorhinolaryngology, Head and Neck Surgery, Osaka, Japan.