Critical Review and Consensus Statement for Neural Monitoring in Otolaryngologic Head, Neck, and Endocrine Surgery

BACKGROUND: Enhancing patient outcomes in an array of surgical procedures in the head and neck requires the maintenance of complex regional functions through the protection of cranial nerve integrity. This review and consensus statement cover the scope of cranial nerve monitoring of all cranial nerves that are of practical importance in head, neck, and endocrine surgery except for cranial nerves VII and VIII within the temporal bone. Complete and applied understanding of neurophysiologic principles facilitates the surgeon\u27s ability to monitor the at-risk nerve. METHODS: The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) identified the need for a consensus statement on cranial nerve monitoring. An AAO-HNS task force was created through soliciting experts on the subject. Relevant domains were identified, including residency education, neurophysiology, application, and various techniques for monitoring pertinent cranial nerves. A document was generated to incorporate and consolidate these domains. The panel used a modified Delphi method for consensus generation. RESULTS: Consensus was achieved in the domains of education needs and anesthesia considerations, as well as setup, troubleshooting, and documentation. Specific cranial nerve monitoring was evaluated and reached consensus for all cranial nerves in statement 4 with the exception of the spinal accessory nerve. Although the spinal accessory nerve\u27s value can never be marginalized, the task force did not feel that the existing literature was as robust to support a recommendation of routine monitoring of this nerve. In contrast, there is robust supporting literature cited and consensus for routine monitoring in certain procedures, such as thyroid surgery, to optimize patient outcomes. CONCLUSIONS: The AAO-HNS Cranial Nerve Monitoring Task Force has provided a state-of-the-art review in neural monitoring in otolaryngologic head, neck, and endocrine surgery. The evidence-based review was complemented by consensus statements utilizing a modified Delphi method to prioritize key statements to enhance patient outcomes in an array of surgical procedures in the head and neck. A precise definition of what actually constitutes intraoperative nerve monitoring and its benefits have been provided

Effect of energy-based devices on voice quality after total thyroidectomy

Voice alteration is an important complication of thyroid surgery and is closely related to patients' quality of life. There are no studies analyzing effect of energy-based devices (EBD) on voice quality (VQ). Aim of this prospective study is to evaluate impact of sutureless total thyroidectomy performed with EBDs on objective voice parameters of patients without recurrent laryngeal nerve (RLN) and/or external branch of superior laryngeal nerve (EBSLN) injury. Sixty patients underwent total thyroidectomy with meticulous dissection of EBSLN. Patients were assigned to Group L (Ligasure (TM)), Group H (Harmonic), or Group C (Conventional) through random ballot. For analysis of alteration in VQ, digital videolaryngostroboscopy (VLS), voice handicap index (VHI), multidimensional voice program (MDVP), and electroglottography (EGG) were used. VLS was performed by 70A degrees-angled indirect laryngoscopy and evaluation was standardized by VLS scale and laryngeal function scoring. This study is registered on clinicaltrials.gov with number NCT01865006. Forty eight patients were female. There was no difference on demographic data. On post-operative laryngoscopic examination, none of the patients had vocal fold palsy. When mean VHI scores at post-operative 1st week and 2nd month were compared to pre-operative values for each groups, groups L and H demonstrated a significant increase in VHI in the early post-operative evaluation, while there was no significant increase for group C. No significant increase was seen in late post-operative period compareYd to pre-operative period for any groups. In the early post-operative period, VQ is better with the conventional technique than EBDs; however, in late post-operative period, VQ is detected better in EBDs (especially in Group L) than the conventional technique, but no statistical difference was observed

The electrophysiology of thyroid surgery: electrophysiologic and muscular responses with stimulation of the vagus nerve, recurrent laryngeal nerve, and external branch of the superior laryngeal nerve

Objectives/Hypothesis: Correlation of physiologically important electromyographic (EMG) waveforms with demonstrable muscle activation is important for the reliable interpretation of evoked waveforms during intraoperative neural monitoring (IONM) of the vagus nerve, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) in thyroid surgery. Study Design: Retrospective chart review. Methods: Data were reviewed retrospectively for thyroid surgery patients with laryngeal nerve IONM from January to December, 2015. EMG responses to monopolar stimulation of the vagus/RLN and EBSLN were recorded in bilateral vocalis, cricothyroid (CTM), and strap muscles using endotracheal tube-based surface and intramuscular hook electrodes, respectively. Target muscles for vagal/RLN and EBSLN stimulation were the ipsilateral vocalis and CTM, respectively. All other recording channels were nontarget muscles. Results: Fifty surgical sides were identified in 37 subjects. All target muscle mean amplitudes were significantly higher than in nontarget muscles. With vagal/RLN stimulation, target ipsilateral vocalis mean amplitude was 1,095.7 \u3bcV (mean difference range = 12814.1 to 121,078 \u3bcV, P <.0001). For EBSLN stimulation, target ipsilateral CTM mean amplitude was 6,379.3 \u3bcV (mean difference range = 126,222.6 to 126,362.3 \u3bcV, P <.0001). Target muscle large-amplitude EMG responses correlated with meaningful visual or palpable muscular responses, whereas nontarget EMG responses showed no meaningful muscle activation. Conclusions: Target and nontarget laryngeal muscles are differentiated based on divergence of EMG response directly correlating with presence or absence of visual and palpable muscle activation. Low-amplitude EMG waveforms in nontarget muscles with neural stimulation can be explained by the concept of far-field artifactual waveforms and do not correspond to a true muscular response. The surgeon should be aware of these nonphysiologic waveforms when interpreting and applying IONM during thyroid surgery. Level of Evidence: 4 Laryngoscope, 127:764\u2013771, 2017

Anterior laryngeal electrodes for recurrent laryngeal nerve monitoring during thyroid and parathyroid surgery : new expanded options for neural monitoring

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:

Immediate and partial neural dysfunction after thyroid and parathyroid surgery: Need for recognition, laryngeal exam, and early treatment

BackgroundLaryngeal dysfunction after thyroid and parathyroid surgery requires early recognition and a standardized approach for patients that present with voice, swallowing, and breathing issues. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to define the terms - immediate vocal fold paralysis- and - partial neural dysfunction- and to provide clinical consensus statements based on review of the literature, integrated with expert opinion of the group.MethodsA multidisciplinary expert panel constructed the manuscript and recommendations for laryngeal dysfunction after thyroid and parathyroid surgery. A meta- analysis was performed using the literature and published guidelines. Consensus was achieved using polling and a modified Delphi approach.ResultsTwenty- two panelists achieved consensus on five statements regarding the role of early identification and standardization of evaluation for patients with - immediate vocal fold paralysis- and - partial neural dysfunction- after thyroid and parathyroid surgery.ConclusionAfter endorsement by the AHNS Endocrine Section and Quality of Care Committee, it received final approval from the AHNS Council.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163592/2/hed26472.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163592/1/hed26472_am.pd