Whitney Liddy1, Bradley R Lawson2, Samuel R Barber2, Dipti Kamani2, Mohamed Shama2, Selen Soylu2, Che Wei Wu3, Feng-Yu Chiang4, Joseph Scharpf5, Marcin Barczynski6, Henning Dralle7, Sam Van Slycke8, Rick Schneider9, Gianlorenzo Dionigi10, Gregory W Randolph2,11. 1. Department of Otolaryngology-Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A. 2. Department of Otolaryngology, Division of Thyroid and Parathyroid Surgery, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, U.S.A. 3. Department of Otorhinolaryngology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. 4. Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. 5. Department of Otolaryngology, Cleveland Clinic, Cleveland, Ohio, U.S.A. 6. Department of Endocrine Surgery, Jagiellonian University Medical College, Third Chair of General Surgery, Krakow, Poland. 7. Department of General Surgery, University Hospital Halle, Halle/Saale, Germany. 8. Onze-Lieve-Vrouw Hospital Aalst, Aalst, Belgium. 9. Department of General, Visceral, and Vascular Surgery, Martin Luther University Halle-Wittenberg, Halle, Germany. 10. Division for Endocrine Surgery, Department of Human Pathology in Adulthood and Childhood "G. Barresi", University Hospital G. Martino, University of Messina, Messina, Italy. 11. Division of Surgical Oncology, Endocrine Surgery Service, Department of Surgery, Massachusetts General Hospital, Division of Surgical Oncology, Endocrine Surgery Service, Boston, Massachusetts, U.S.A.
Abstract
OBJECTIVES/HYPOTHESIS: Intraoperative neural monitoring is a useful adjunct for the laryngeal nerve function assessment during thyroid and parathyroid surgery. Typically, monitoring is performed by measurement of electromyographic responses recorded by endotracheal tube (ETT) surface electrodes. Tube position alterations during surgery can cause displacement of the electrodes relative to the vocal cords, leading to false positive loss of signal. Numerous reports have denoted monitoring equipment-related issues, especially endotracheal tube displacement, as the dominant source of false positive error. The false positive error may result in inappropriate decisions by the surgeon. This study tests the hypothesis that anterior laryngeal electrodes (ALEs) can help reduce this error. Placement of ALEs directly onto the thyroid cartilage represent an adjunctive and possible alternative method to standard ETT surface electrodes. STUDY DESIGN: Retrospective review. METHODS: Fifteen consecutive patients undergoing thyroid and parathyroid surgery with intraoperative neuromonitoring using both ETT electrodes and ALEs were studied. Data collected included site of neural stimulation, laterality, and electromyographic parameters. RESULTS: With vagal and recurrent laryngeal nerve stimulation, the ALEs recorded mean vocalis muscle waveform amplitude within 83% of that recorded with standard ETT electrodes. The latency measurements with the anterior laryngeal and endotracheal electrodes were similar, with both electrodes recording significantly longer latency for the left vagus nerve as compared to the right vagus nerve. With superior laryngeal nerve stimulation, the ALEs recorded a 800% greater mean amplitude than the ETT electrodes. The ALEs demonstrated similar sensitivity to stimulation at low current as ETT electrodes and provided stable intraoperative monitoring information. CONCLUSIONS: Compared to ETT surface electrodes, the ALEs provide similar and stable electromyographic responses with equal sensitivity for recording evoked responses during neural monitoring in thyroid and parathyroid surgery. The ALEs offer significantly more robust monitoring of the external branch of the superior laryngeal nerve. Furthermore, ALEs are contained within the operative field, are totally surgeon controlled, and are unaffected by the potential vicissitudes of ETT position during surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 128:2910-2915, 2018.
OBJECTIVES/HYPOTHESIS: Intraoperative neural monitoring is a useful adjunct for the laryngeal nerve function assessment during thyroid and parathyroid surgery. Typically, monitoring is performed by measurement of electromyographic responses recorded by endotracheal tube (ETT) surface electrodes. Tube position alterations during surgery can cause displacement of the electrodes relative to the vocal cords, leading to false positive loss of signal. Numerous reports have denoted monitoring equipment-related issues, especially endotracheal tube displacement, as the dominant source of false positive error. The false positive error may result in inappropriate decisions by the surgeon. This study tests the hypothesis that anterior laryngeal electrodes (ALEs) can help reduce this error. Placement of ALEs directly onto the thyroid cartilage represent an adjunctive and possible alternative method to standard ETT surface electrodes. STUDY DESIGN: Retrospective review. METHODS: Fifteen consecutive patients undergoing thyroid and parathyroid surgery with intraoperative neuromonitoring using both ETT electrodes and ALEs were studied. Data collected included site of neural stimulation, laterality, and electromyographic parameters. RESULTS: With vagal and recurrent laryngeal nerve stimulation, the ALEs recorded mean vocalis muscle waveform amplitude within 83% of that recorded with standard ETT electrodes. The latency measurements with the anterior laryngeal and endotracheal electrodes were similar, with both electrodes recording significantly longer latency for the left vagus nerve as compared to the right vagus nerve. With superior laryngeal nerve stimulation, the ALEs recorded a 800% greater mean amplitude than the ETT electrodes. The ALEs demonstrated similar sensitivity to stimulation at low current as ETT electrodes and provided stable intraoperative monitoring information. CONCLUSIONS: Compared to ETT surface electrodes, the ALEs provide similar and stable electromyographic responses with equal sensitivity for recording evoked responses during neural monitoring in thyroid and parathyroid surgery. The ALEs offer significantly more robust monitoring of the external branch of the superior laryngeal nerve. Furthermore, ALEs are contained within the operative field, are totally surgeon controlled, and are unaffected by the potential vicissitudes of ETT position during surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 128:2910-2915, 2018.
Authors: Sam Van Slycke; K Van Den Heede; K Magamadov; N Brusselaers; H Vermeersch Journal: Langenbecks Arch Surg Date: 2019-11-20 Impact factor: 3.445