Rick Schneider1, Gregory Randolph2, Gianlorenzo Dionigi3, Marcin Barczynski4, Feng-Yu Chiang5, Che-Wei Wu5, Thomas Musholt6, Mehmet Uludag7, Özer Makay8, Atakan Sezer9, Serkan Teksöz10, Theresia Weber11, Carsten Sekulla1, Kerstin Lorenz1, Murat Özdemir8, Andreas Machens1, Henning Dralle12. 1. Department of Visceral, Vascular, and Endocrine Surgery, University Hospital of Martin Luther University, Halle (Saale), Germany. 2. Division of Thyroid and Parathyroid Surgery, Harvard Medical School, Boston, Massachusetts, U.S.A. 3. Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital "G. Martino," University of Messina, Messina, Italy. 4. Department of Endocrine Surgery, Third Chair of General Surgery, Jagiellonian University Medical College, Faculty of Medicine, Kraków, Poland. 5. Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University, Kaohsiung, Taiwan. 6. Endocrine Surgery Section, Clinic of General, Visceral and Transplantation Surgery, University Medical Center, Mainz, Germany. 7. Department of General Surgery, Sisli Hamidiye Etfal Medical Practice and Research Center, University of Health Sciences, Istanbul, Turkey. 8. Department of General Surgery, Ege University, Izmir, Turkey. 9. Department of General Surgery, Trakya University, Edirne, Turkey. 10. Department of General Surgery, Cerrahpasa Medical Faculty, Istanbul, Turkey. 11. Department of Endocrine Surgery, Catholic Hospital, Mainz, Germany. 12. Department of General, Visceral, and Transplantation Surgery, Section of Endocrine Surgery, University of Duisburg-Essen, Essen, Germany.
Abstract
OBJECTIVES/HYPOTHESIS: This multicenter study aimed to 1) evaluate early postoperative vocal fold function in relation to intraoperative amplitude recovery, and 2) determine optimal absolute and relative thresholds of intraoperative amplitude recovery heralding normal early postoperative vocal fold function, both after segmental type 1 and after global type 2 loss of signal (LOS). STUDY DESIGN: Prospective outcome study. METHODS: This study, encompassing nine surgical centers from four countries, correlated intraoperative amplitude recovery with early postoperative vocal fold function using receiver operating characteristic analysis. RESULTS: Included in this study were 68 patients, 48 women and 20 men, who sustained transient recurrent laryngeal nerve injury during thyroid surgery under continuous intraoperative nerve monitoring. Early transient vocal fold palsy was seen in 18 (64%) of 28 patients with ipsilateral segmental LOS type 1, and in 10 (25%) of 40 patients with ipsilateral global LOS type 2. On receiver operating characteristic analysis, relative amplitude thresholds were superior to absolute amplitude thresholds in predicting vocal fold function after LOS type 2 (area under the curve [AUC]: 0.83 vs. 0.65; P = .01 vs. P = .15; Youden index 44% and 253 µV) and LOS type 1 (AUC: 0.96 vs. 0.97; P < .001 each; Youden index 49% and 455 µV). Amplitude recovery ≥50% of baseline after LOS always indicated intact vocal fold function. CONCLUSIONS: When the nerve amplitude recovers ≥50% of baseline after segmental LOS type 1 or global LOS type 2, it is appropriate to extend completion thyroidectomy to the other side during the same session. LEVEL OF EVIDENCE: 2b Laryngoscope, 129:525-531, 2019.
OBJECTIVES/HYPOTHESIS: This multicenter study aimed to 1) evaluate early postoperative vocal fold function in relation to intraoperative amplitude recovery, and 2) determine optimal absolute and relative thresholds of intraoperative amplitude recovery heralding normal early postoperative vocal fold function, both after segmental type 1 and after global type 2 loss of signal (LOS). STUDY DESIGN: Prospective outcome study. METHODS: This study, encompassing nine surgical centers from four countries, correlated intraoperative amplitude recovery with early postoperative vocal fold function using receiver operating characteristic analysis. RESULTS: Included in this study were 68 patients, 48 women and 20 men, who sustained transient recurrent laryngeal nerve injury during thyroid surgery under continuous intraoperative nerve monitoring. Early transient vocal fold palsy was seen in 18 (64%) of 28 patients with ipsilateral segmental LOS type 1, and in 10 (25%) of 40 patients with ipsilateral global LOS type 2. On receiver operating characteristic analysis, relative amplitude thresholds were superior to absolute amplitude thresholds in predicting vocal fold function after LOS type 2 (area under the curve [AUC]: 0.83 vs. 0.65; P = .01 vs. P = .15; Youden index 44% and 253 µV) and LOS type 1 (AUC: 0.96 vs. 0.97; P < .001 each; Youden index 49% and 455 µV). Amplitude recovery ≥50% of baseline after LOS always indicated intact vocal fold function. CONCLUSIONS: When the nerve amplitude recovers ≥50% of baseline after segmental LOS type 1 or global LOS type 2, it is appropriate to extend completion thyroidectomy to the other side during the same session. LEVEL OF EVIDENCE: 2b Laryngoscope, 129:525-531, 2019.