Kai-Pun Wong1, Jung-Woo Woo2, Yeo-Kyu Youn2, Felix Che-Lok Chow1, Kyu Eun Lee2, Brian Hung-Hin Lang3. 1. Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China. 2. Department of Surgery, Seoul National University Hospital and College of Medicine, Seoul, Korea; Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea. 3. Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong SAR, China. Electronic address: blang@hkucc.hku.hk.
Abstract
INTRODUCTION: During examination of the vocal cords (VC) using transcutaneous laryngeal ultrasonography (TLUSG), 3 sonographic landmarks (namely, false VC [FC], true VC [TC], and arytenoids [AR]) are often seen. However, it remains unclear which landmark provides a more reliable assessment and whether seeing more landmarks improves the diagnostic accuracy and reliability. METHODS: We evaluated prospectively 245 patients from 2 centers. One assessor from each center performed all TLUSG examinations and their findings were validated by direct laryngoscopy. All 3 sonographic landmarks were routinely visualized whenever possible. The rate of visualization and diagnostic accuracy between the 3 landmarks were compared. RESULTS: Eighteen patients suffered postoperative VC palsy (VCP). Both centers had comparable visualization or assessability rate of ≥ 1 sonographic landmark (94.9 and 95.3%; P = 1.000) and 100% sensitivity on postoperative TLUSG. The rates of FC, TC, and AR visualization were 92.7%, 36.7%, and 89.8%, respectively. The sensitivity, specificity, and diagnostic accuracy and the proportion of true positives, false positives, and true negatives between using 1, 2, landmarks and 3 landmarks were comparable (P > .05). CONCLUSION: Each sonographic landmark had similar reliability and diagnostic accuracy. Identifying all 3 sonographic landmarks was not mandatory and visualizing normal movement in one of the sonographic landmarks would be sufficient to exclude VCP.
INTRODUCTION: During examination of the vocal cords (VC) using transcutaneous laryngeal ultrasonography (TLUSG), 3 sonographic landmarks (namely, false VC [FC], true VC [TC], and arytenoids [AR]) are often seen. However, it remains unclear which landmark provides a more reliable assessment and whether seeing more landmarks improves the diagnostic accuracy and reliability. METHODS: We evaluated prospectively 245 patients from 2 centers. One assessor from each center performed all TLUSG examinations and their findings were validated by direct laryngoscopy. All 3 sonographic landmarks were routinely visualized whenever possible. The rate of visualization and diagnostic accuracy between the 3 landmarks were compared. RESULTS: Eighteen patients suffered postoperative VC palsy (VCP). Both centers had comparable visualization or assessability rate of ≥ 1 sonographic landmark (94.9 and 95.3%; P = 1.000) and 100% sensitivity on postoperative TLUSG. The rates of FC, TC, and AR visualization were 92.7%, 36.7%, and 89.8%, respectively. The sensitivity, specificity, and diagnostic accuracy and the proportion of true positives, false positives, and true negatives between using 1, 2, landmarks and 3 landmarks were comparable (P > .05). CONCLUSION: Each sonographic landmark had similar reliability and diagnostic accuracy. Identifying all 3 sonographic landmarks was not mandatory and visualizing normal movement in one of the sonographic landmarks would be sufficient to exclude VCP.