Superiority of continuous over intermittent intraoperative nerve monitoring in preventing vocal cord palsy.
Schneider R,Machens A,Sekulla C,Lorenz K,Elwerr M,Dralle H
The British journal of surgery
BACKGROUND:Continuous intraoperative nerve stimulation (IONM) with uninterrupted monitoring is likely better than intermittent IONM in preventing vocal cord palsy after thyroid surgery. METHODS:This was a comparative study of intermittent versus continuous IONM in patients with benign and malignant thyroid disease treated at a tertiary centre over 10 years. Early postoperative and permanent vocal cord palsy rates were estimated. Multivariable logistic regression analysis was used to quantify the contributions of clinical and histopathological variables to early postoperative and permanent vocal cord palsy. RESULTS:A total of 6029 patients were included, of whom 3139 underwent continuous and 2890 intermittent IONM. Based on nerves at risk (5208 versus 5024 nerves), continuous IONM had a 1·7-fold lower early postoperative vocal cord palsy rate than intermittent monitoring (1·5 versus 2·5 per cent). This translated into a 30-fold lower permanent vocal cord palsy rate (0·02 versus 0·6 per cent). In multivariable logistic regression analysis, continuous IONM independently reduced early postoperative vocal cord palsy 1·8-fold (odds ratio (OR) 0·56) and permanent vocal cord palsy 29·4-fold (OR 0·034) compared with intermittent IONM. One permanent vocal cord palsy per 75·0 early vocal cord palsies was observed with continuous IONM, compared with one per 4·2 after intermittent IONM. Early postoperative vocal cord palsies were 17·9-fold less likely to become permanent with continuous than intermittent IONM. CONCLUSION:Continuous IONM is superior to intermittent IONM in preventing vocal cord palsy.
10.1002/bjs.11901
The utility of intraoperative nerve monitoring during thyroid surgery.
Brajcich Brian C,McHenry Christopher R
The Journal of surgical research
BACKGROUND:Damage to the recurrent laryngeal nerve (RLN) can lead to vocal cord paralysis, resulting in hoarseness, aspiration, stridor, and respiratory distress. The purpose of this study was to examine the impact of intraoperative nerve monitoring (IONM) on RLN injury during thyroidectomy when it is used as an adjunct to confirm the functional integrity of the RLN during delineation of its anatomic course after it has been visually identified. METHODS:A retrospective cohort study was performed comparing the rate of RLN injury in patients undergoing thyroidectomy with IONM, which was implemented in 2012, to patients who underwent thyroidectomy without IONM during the 3-year period immediately before IONM. Secondary analysis was performed to determine if there was a relationship between RLN injury and patient age, sex, substernal extension, central neck dissection, prior neck surgery, nodule size, gland weight, or pathology. RESULTS:A total of 627 patients underwent thyroidectomy, 315 with IONM and 312 without IONM. Of the 531 nerves at risk in the cohort with IONM, 4 (0.75%) were injured compared to 3 (0.58%) among the 517 nerves at risk in the cohort without IONM (P > 0.05). No secondary factor had a significant impact on RLN injury. CONCLUSIONS:The use of IONM had no impact on the rate of permanent RLN injury during thyroidectomy. Because of the low rate of RLN injury, a much larger sample size is needed to determine if IONM will a valuable adjunct in thyroid surgery, especially in specific high-risk subgroups.
10.1016/j.jss.2016.04.039
Intraoperative neuromonitoring for early localization and identification of recurrent laryngeal nerve during thyroid surgery.
Chiang Feng-Yu,Lu I-Cheng,Chen Hui-Chun,Chen Hsiu-Ya,Tsai Cheng-Jing,Lee Ka-Wo,Hsiao Pi-Jung,Wu Che-Wei
The Kaohsiung journal of medical sciences
Early and definite identification of the recurrent laryngeal nerve (RLN) is an important step to avoid inadvertent nerve injury during complicated thyroid operations. This study aimed to determine the feasibility of routine use of intraoperative neuromonitoring (IONM) to localize and identify the RLN at an early stage of thyroid surgery. This prospective study enrolled 220 consecutive patients (333 RLNs at risk) who underwent thyroid operations with application of IONM. The RLN was localized and identified routinely with a nerve stimulator after opening the space between the thyroid and carotid sheath. The success rates of early RLN localization and identification were evaluated. The current for localization and the amplitude of evoked laryngeal electromyographic signals were also recorded and analyzed. All RLNs, including 87 (26%) nerves that were regarded as difficult to identify, were successfully localized and identified. The stimulation level for RLN localization was 2mA in 315 nerves (95%) and 3mA in the other 18 nerves (5%). The signal obtained from RLN localization (amplitude = 932 ±436μV) showed a clear and reliable laryngeal electromyographic response that was similar to that from direct vagus (amplitude=811±389μV) or RLN stimulation (amplitude=1132±472μV). The palsy rate was 0.6% and no permanent palsy occurred. RLN injury is rare if the nerve is definitely identified early in the thyroid operation. The conclusion of this study is that IONM is a reliable tool for early RLN localization and identification, even in complicated thyroid operations.
10.1016/S1607-551X(10)70097-8
Systematic use of recurrent laryngeal nerve neuromonitoring changes the operative strategy in planned bilateral thyroidectomy.
Sadowski Samira Mercedes,Soardo Pietro,Leuchter Igor,Robert John Henri,Triponez Frederic
Thyroid : official journal of the American Thyroid Association
BACKGROUND:One of the worst complications in thyroid surgery is bilateral recurrent laryngeal nerve paralysis, which can lead to transient or definitive tracheotomy. METHODS:We implemented a strict standard operative procedure beginning in January 2010 and modified our operative procedure. In all patients undergoing bilateral operation, we begin with the largest side or with the cancerous/suspicious side without dissecting the contralateral side. If the intraoperative neuromonitoring (IONM) signal is lost after stimulation of the vagus nerve at the end of the first side, we stop the procedure after the unilateral lobectomy, even if the recurrent nerve is anatomically intact and regardless of malignancy. If the IONM signal is lost, serial laryngoscopies are performed until recovery or definitive recurrent laryngeal nerve palsy is demonstrated. We report here our results in patients with loss of the IONM signal after lobectomy and discuss the medical implications for benign and malignant thyroid conditions. RESULTS:Since January 2010, the operation has been stopped at the first side in 9 out of 220 planned bilateral thyroidectomies. There were five benign thyroid conditions and four thyroid cancers, including three papillary thyroid cancers and one bilateral medullary thyroid cancer in a patient with multiple endocrine neoplasia 2a. In two patients, it was a false-positive IONM loss. One of these two patients had the other lobe removed at day 3. In seven patients the laryngoscopy demonstrated total or partial laryngeal nerve palsy at day 1, but the recurrent nerve function recovered fully in all patients between 1 and 4 months postoperatively. All cancer patients were operated on the other side within 3 days to 3 months; one patient with a benign condition is being followed conservatively. One of the eight re-operated patients had transient recurrent nerve palsy postoperatively. CONCLUSION:In our opinion, the systematic use of IONM and the change in operative strategy will lead to an almost 0% rate of bilateral laryngeal nerve palsy, at least in benign thyroid conditions. A loss of signal after the first side should prompt a halt in the procedure, even in cases of malignancies.
10.1089/thy.2012.0368
Thyroid surgery and the usefulness of intraoperative neuromonitoring, a single center study.
de Danschutter Sophie J R,Schreinemakers Jennifer M J,Smit Leoni H M,van der Laan Lijckle,Nuytinck Hans K S
Journal of investigative surgery : the official journal of the Academy of Surgical Research
UNLABELLED:Purpose/Aim of study: To compare the use of intraoperative neuromonitoring (IONM) versus visualization of the recurrent laryngeal nerve (RLN) alone in thyroid surgery with regard to incidence in postoperative RLN injury and operation time. MATERIALS AND METHODS:This retrospective cohort study was performed in the Amphia Hospital, the Netherlands. All thyroid gland operations were collected from September 2009 to October 2012. For each case we recorded the patient characteristics, indication for surgery, intraoperative data, complications, results of pathological evaluation, and consultation of a ENT-surgeon. Research of current literature and statistical analysis was performed. RESULTS:In total, 147 patients were included and classified into an IONM and non-IONM group. Both groups were similar in demographical aspects and indications for surgery. In total, we had 170 nerves at risk (NAR). In both groups, there were 85 (50%) NAR. Overall injury to the RLN was 6%. A statistical significant decrease of permanent RLN injuries was noticed in the IONM group compared to the non-IONM group (n = 0 vs n = 6; p = .044). In transient RLN injury, no difference was noticed (n = 2 vs n = 2). Operation time with or without IONM was not significantly different for hemithyroidectomies, neither for total thyroidectomies. CONCLUSION:IONM is a useful tool as an adjunct in thyroid surgery to prevent RLN injury. A statistical significant decrease in permanent RLN injury with the use of IONM was found, but it did not significantly decrease time of operation.
10.3109/08941939.2014.975876
A functional assessment of anatomical variants of the recurrent laryngeal nerve during thyroidectomies using neuromonitoring.
Endocrine
PURPOSE:The aim of the study was to assess the usefulness of intraoperative neuromonitoring (IONM) in identifying anatomical variants of the recurrent laryngeal nerve (RLN) during thyroidectomies, with emphasis on the nerve's relationship to the inferior thyroid artery (ITA), Zuckerkandl's tubercle, nonrecurrent laryngeal nerves (NRLNs), and extralaryngeal bifurcation. METHODS:A total of 128 subjects undergoing surgery for thyroid disorders were enrolled in the study, and the course and anatomical variants of RLN were assessed with IONM application. RESULTS:The standard relationship between RLN and ITA was that the artery and nerve intersect (100%). The right RLN was below the ITA in 76.67% of the patients, and the left RNL was below it in 75.81%. There were no statistically significant differences in the relationship between RLN and ITA on the two sides; and gender did not significantly influence the relationship between the RLN and ITA on either side. In one patient a nonrecurrent inferior laryngeal nerve was present on the right side (0.83%). RLN bifurcation was observed in 33.33% of the patients on the right and in 19.35% on the left side; the difference between sides was statistically significant (p < 0.05). Posterior tubercle (Zuckerkandl's tubercle) was observed on the right in 83% of the subjects and on the left in 69%. The age, thyroid volume and body mass index (BMI) did not influence the size of the tumor. CONCLUSIONS:The utilization of IONM of the RLN in thyroid surgery adds a new dimension to the standard of visual nerve identification allowing for functional nerve testing at the most vulnerable area of the dissection: at the level of Berry's ligament, posterior tubercle (Zuckerkandl's tubercle) and crossing of the RLN with the inferior thyroid artery.
10.1007/s12020-017-1466-3
Intraoperative neuromonitoring in thyroid surgery: Is the two-staged thyroidectomy justified?
Calò Pietro Giorgio,Medas Fabio,Conzo Giovanni,Podda Francesco,Canu Gian Luigi,Gambardella Claudio,Pisano Giuseppe,Erdas Enrico,Nicolosi Angelo
International journal of surgery (London, England)
BACKGROUND:The aim of this study was to evaluate the diagnostic accuracy of intraoperative neuromonitoring (IONM) in predicting postoperative nerve function during thyroid surgery and its consequent ability to assist the surgeon in intraoperative decision making. MATERIALS AND METHODS:A total of 2365 consecutive patients were submitted to thyroidectomy by the same surgical team. Group A included 1356 patients (2712 nerves at risk) in whom IONM was utilized, and Group B included 1009 patients (2018 nerves at risk) in whom IONM was not utilized. RESULTS:In Group A, loss of signal (LOS) was observed in 37 patients; there were 29 true positive, 1317 true negative, 8 false positive, and 2 false negative cases. Accuracy was 99.3%, positive predictive value was 78.4%, negative predictive value was 99.8%, sensitivity was 93.6%, and specificity was 99.4%. A total of 29 (2.1%) cases of unilateral paralysis were observed, 23 (1.7%) of which were transient and 6 (0.4%) of which were permanent. Bilateral palsy was observed in two (0.1%) cases requiring a tracheostomy. In Group A, 31 (2.3%) injuries were observed, 25 (1.8%) of which were transient and 6 (0.4%) of which were permanent. In Group B, 26 (2.6%) unilateral paralysis cases were observed, 20 (2%) of which were transient and 6 (0.6%) of which were permanent; bilateral palsy was observed in 2 (0.2%) cases. In Group B, 28 (2.8%) injuries were observed, 21 (2.1%) of which were transient and 7 (0.7%) of which were permanent. Differences between the two groups were not statistically significant. CONCLUSIONS:Our results show that IONM has a very high sensitivity and negative predictive value, but also good specificity and positive predictive value. For these reasons, in selected patients with LOS, the surgical strategy should be reconsidered. However, patients need to be informed preoperatively about potential strategy changes during the planned bilateral surgery. Future larger and multicenter studies are needed to confirm the benefits of this therapeutic strategy.
10.1016/j.ijsu.2017.02.001
Prospective study of vocal fold function after loss of the neuromonitoring signal in thyroid surgery: The International Neural Monitoring Study Group's POLT study.
Schneider Rick,Randolph Gregory,Dionigi Gianlorenzo,Barczyński Marcin,Chiang Feng-Yu,Triponez Frédéric,Vamvakidis Kyriakos,Brauckhoff Katrin,Musholt Thomas J,Almquist Martin,Innaro Nadia,Jimenez-Garcia Antonio,Kraimps Jean-Louis,Miyauchi Akira,Wojtczak Beata,Donatini Gianluca,Lombardi Davide,Müller Uwe,Pezzullo Luciano,Ratia Tomas,Van Slycke Sam,Nguyen Thanh Phuong,Lorenz Kerstin,Sekulla Carsten,Machens Andreas,Dralle Henning
The Laryngoscope
OBJECTIVES/HYPOTHESIS:Intraoperative neuromonitoring identifies recurrent laryngeal nerve (RLN) injury and gives prognostic information regarding postoperative glottic function. Loss of the neuromonitoring signal (LOS) signifies segmental type 1 or global type 2 RLN injury. This study aimed at identifying risk factors for RLN injury and determining vocal fold (VF) function initially and 6 months after definitive LOS. STUDY DESIGN:Prospective study encompassing 21 hospitals from 13 countries. METHODS:Included in this study were patients with persistent intraoperative LOS. RESULTS:At first postoperative laryngoscopy, early VF palsy was present in 94 of all 115 patients with LOS (81.7%): in 53 of 56 patients (94.6%) with type 1 injury and 41 of 59 patients (69.5%) with type 2 injury. In LOS type 1, women outnumbered men >5-fold. Traction produced LOS type 1 in 38 of 56 patients (67.9%) and LOS type 2 in 54 of 59 patients (91.5%). Course of the RLN posterior and/or anterior to the inferior thyroid artery, extralaryngeal branching, or tuberculum of Zuckerkandl did not increase VF palsy rates. Permanent VF palsy rates were also lower (P = .661) after LOS type 2 than after LOS type 1: 6.8% (four of 59 patients) versus 10.7% (six of 56 patients). Intraoperative administration of steroids did not diminish postoperative VF palsy rates. CONCLUSIONS:LOS type 1 entails more severe nerve damage than LOS type 2, affecting women disproportionately. Both LOS types, being primarily associated with traction injury, are unaffected by variant neck anatomy in expert hands and unresponsive to steroids. LEVEL OF EVIDENCE:2b Laryngoscope, 126:1260-1266, 2016.
10.1002/lary.25807
Trends in intraoperative neural monitoring for thyroid and parathyroid surgery amongst otolaryngologists and general surgeons.
Ho Yan,Carr Michele M,Goldenberg David
European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery
The role of intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery remains a controversial subject for surgeons regardless of surgical training and background. This study aims to compare usage patterns and motivations behind IONM among otolaryngologist-head and neck surgeons (OTO-HNS) and general surgeons (GS) performing thyroid and parathyroid surgery. The study is a multi-institution survey of 103 otolaryngology and affiliated 103 GS programs in the US. 206 surveys were sent to OTO-HNS and GS academic program directors with a response rate of 44.7 %. Of those who performed thyroid surgery, 80.6 % of OTO-HNS and 48.0 % of GS surgeons reported using IONM. 44.3 % of OTO-HNS and 30.8 % of GS respondents used IONM in all thyroid cases. For thyroid surgery, as surgical volume increased, surgeons were more likely to use IONM more frequently. Fourteen percent (14 %) of the OTO-HNS and 41.7 % of the GS respondents used IONM primarily to locate the RLN. Forty percent (40 %) of the OTO-HNS and 8.3 % of the GS used IONM for medicolegal reasons. The majority of OTO-HNS programs use IONM for thyroid and parathyroid surgery, whereas less than half of GS programs regularly use IONM for these surgeries. Thyroid surgeons, with larger thyroid surgery volume, regardless of discipline, tend to use IONM more. The motivations for using IONM differ significantly between OTO-HNS and general surgeons in that more GS use it for locating the RLN, and more OTO-HNS use it for continuous monitoring of the nerve during resection and for medicolegal purposes.
10.1007/s00405-013-2359-6
Optimal stimulation during monitored thyroid surgery: EMG response characteristics in a porcine model.
Wu Che-Wei,Liu Xiaoli,Barczyński Marcin,Kim Hoon Yub,Dionigi Gianlorenzo,Sun Hui,Chiang Feng-Yu,Kamani Dipti,Randolph Gregory W
The Laryngoscope
OBJECTIVES:To compare electromyography (EMG) characteristics of the external branch of superior laryngeal nerve (EBSLN), recurrent laryngeal nerve (RLN), and vagus nerve (VN) evoked with different stimulation probes/dissectors during monitored thyroid surgery. STUDY DESIGN:Experimental porcine model. METHODS:In five piglets (10 EBSLNs/RLNs/VNs), laryngeal EMG was recorded by endotracheal tube surface electrodes with stimulation using five monopolar probes (group I), three bipolar probes (group II), and two stimulation dissectors (group III). The detectable EMG response (DER) was defined as > 100 μV and was obtained with these different probes/dissectors. Electromyography parameters, stimulus-response curve, and distance-sensitivity results were compared. RESULTS:All stimulation probes/dissectors evoked typical EMG waveforms from the EBSLN/RLN/VN with 1 mA current. A stimulus-response curve with increasing EMG amplitude with increase in stimulating current was noted, with the maximum EMG elicited by group I/III probes/dissectors at < 1 mA and at a higher current for group II probes. All groups recorded lower evoked EMG amplitudes when the nerve was stimulated with overlying fascia or when probe/dissector to nerve distance was greater. The mean amplitude decreased by 11%/33%/13% in group I/II/III probes/dissectors when stimulating nerves covered by fascia versus nerves dissected free of overlying fascia. The rate of obtaining DER at 1- or 2-mm distance was significantly higher in group I than in group II/III probes/dissectors (P < 0.001). Latency did not change with any of the stimulation probes/dissectors or trials. CONCLUSION:Monopolar, bipolar probes, and newer stimulation dissectors all provided valid evoked VN/RLN/EBSLN waveforms. They have different functional sensitivity profiles and vary when stimulating with fascia and at a distance from the nerve. Selection of a stimulation probe/dissector for nerve monitoring can be based on the stimulation characteristics, the intended nerve monitoring application, and the surgeon's preference. LEVEL OF EVIDENCE:N/A. Laryngoscope, 127:998-1005, 2017.
10.1002/lary.26141
The area under the waveform of electromyography for monitoring the external branches of the superior laryngeal nerve during thyroid surgery.
Zhao Yishen,Zhao Zihan,Wang Tie,Zhang Daqi,Dionigi Gianlorenzo,Sun Hui
Gland surgery
Background:Injuries to the external branches of the superior laryngeal nerve (EBSLN) are difficult to identify during thyroidectomy. Monitoring the low amplitudes of the EBSLN during surgery has proven to be complicated. Therefore a new parameter, the area under the waveform (AUW), was designed to improve monitoring efficiency. The aim of this study was to determine the effectiveness of using AUW to monitor the EBSLN during thyroidectomy. Methods:A total of 927 patients and 927 recurrent laryngeal nerves (RLN) and EBSLNs who underwent monitored unilateral thyroidectomy were included. Standardized intraoperative neuromonitoring procedures were followed. RLN injuries were confirmed using stroboscopic laryngoscopy after surgery. EBSLN injuries were identified by means of observing changes in cricothyroid muscle (CTM) twitches when stimulated. Amplitude and AUW changes were assessed using statistical analysis. The correlations between AUW and amplitude were verified using the ratio of the two parameters to determine any decreases that were observed in the number of nerve injury cases. The receiver operating characteristic (ROC) curve was used to estimate the prediction of nerve injury. Results:The overall injury rates of the RLN and EBSLN were 3.56% and 2.05%, respectively. The AUW for the RLN and EBSLN presented linear correlations with amplitude. In the RLN injury cases, no significant difference was observed between the two parameters (P>0.05). In the cases with EBSLN injuries, the AUW decreased 64.5%±14.1%, on average, which was a greater decrease compared to that observed for amplitude 49.7%±22.2% (P<0.0001). The summary of the EBSLN injury prediction included, amplitude AUW, AUC: 0.918 0.994; P<0.0001, and Youden's index: 31.54% 49.58%. Conclusions:The AUW demonstrated consistency with the change in amplitude, and the observed changes were significant. The use of the AUW allowed successful predictions for both RLN and EBSLN nerve injuries. Also, the sensitivity of AUW was greater than amplitude for predicting EBSLN injuries.
10.21037/gs-20-570
Voice quality preservation in thyroid surgery with neuromonitoring.
Wojtczak Beata,Sutkowski Krzysztof,Kaliszewski Krzysztof,Forkasiewicz Zdzisław,Knychalski Bartłomiej,Aporowicz Michał,Bolanowski Marek,Barczyński Marcin
Endocrine
PURPOSE:Voice problems are common after thyroidectomy. The aim of this study was to assess the voice related quality of life after thyroidectomy with neuromonitoring. The sociodemographic and treatment factors influencing the quality of voice after the operation were investigated. METHODS:A total of 40 patients after thyroidectomy with neuromonitoring were enrolled into the study. The voice outcome was analyzed pre and postoperatively by two validated self-assessment questionnaires: Voice Handicap Index and Voice-Related Quality of Life survey. RESULTS:All external branches of the superior laryngeal nerve were identified during the operation. There were no recurrent laryngeal nerve palsies. The mean total VHIs before and after thyroid operation were 1.2 [SD 2.564] and 2.8 [SD 6.944], respectively (p = 0.5). Preoperatively, the mean overall score for the V-RQOL was 99.6; postoperatively 98.7 (p = 0.05). A strong correlation between the V-score of the V-RQOL and O-score of the VHI before and after thyroidectomy was observed (both p < 0.001). There was no correlation between V-RQOL or VHI and sex, the kind of thyroid operations, diagnosis, thyroid function, the mean volume of the goitre, the presence of retrosternal position and the extent of thyroid operations (p > 0.05). A small correlation between the mean age of the patients and postoperative O-Score of the VHI (p = 0.007650) and between the mean age and postoperative V-Score for the V-RQOL (p = 0.00648) was observed. CONCLUSIONS:The use of neuromonitoring in thyroid surgery is beneficial for patients to improve voice quality. The identification and preservation of EBSLNs is crucial to eliminate altered voice after thyroidectomy.
10.1007/s12020-018-1614-4
Routine Preoperative Laryngoscopy for Thyroid Surgery Is Not Necessary Without Risk Factors.
Maher Dominic I,Goare Stephanie,Forrest Edward,Grodski Simon,Serpell Jonathan W,Lee James C
Thyroid : official journal of the American Thyroid Association
Routine preoperative vocal cord (VC) assessment with laryngoscopy in patients undergoing thyroidectomy allows clear documentation of baseline VC function, aids in surgical planning in patients with palsies, and facilitates interpretation of intraoperative neuromonitoring (IONM) findings. We aimed to determine the incidence of preoperative vocal cord palsy (VCP); to evaluate the associated risk factors for preoperative VCP; and to calculate the cost-savings potential of implementing a selective approach. Patients with a pre-thyroidectomy VC assessment by fiberoptic laryngoscopy were retrospectively recruited from the Monash University Endocrine Surgery Unit database from 2000 to 2018. Cases with preoperative VCP were reviewed for potential contributing factors and compared with a non-palsy cohort. Of the 5987 patients who had preoperative laryngoscopy, VCP was documented in 41 (0.68%) patients. Four clinical parameters were found to be potential indicators of VCP, including: age ( < 0.001), nodule ≥3.5 cm recorded on ultrasound imaging ( = 0.01), presence of voice symptoms ( < 0.001), and previous neck surgery ( < 0.001). Malignant cytology ( = 0.5) and exposure to head and neck irradiation were not different between the groups. Utilizing these risk factors, 2354 (39%) patients had at least one feature that may raise suspicion for preoperative VCP. By performing preoperative laryngoscopy only on this subset of patients, the potential cost savings exceeds 400 Australian Dollars per patient. Using this large dataset, we have established that a VCP is rare in the absence of a large nodule, hoarseness, or previous neck surgery. Therefore, in the era of IONM, we support a selective approach to preoperative laryngoscopy by using the aforementioned criteria.
10.1089/thy.2019.0145
[Autoplasty of recurrent laryngeal nerve in the thyroid gland surgery].
Palamarchuk V A
Klinichna khirurhiia
Efficacy of autoplasty of recurrent laryngeal nerve (RLN) for laryngeal reinnervation in surgery of differentiated cancer of thyroid gland was studied. Prospectively 8 patients were examined, in whom laryngeal reinnervation, using the RLN autoplasty, for the abduction laryngeal paralysis was done. The examination was performed before and after the operation, it included videolaryngoscopy, acoustic analysis and the patient's self-estimation of psychosocial consequences of the voice-formation disturbance. Improvement of a vocal cords spacious positioning was noted in 38% patients, and was confirmed by trustworthy improvement of the voice-formating parameters after the operation, comparing with a preoperative state. In 72% patients the vocal aperture closure was incomplete and the voice-formation parameters trustworthy differed from such in patients of a control group. When the intact alternative nerves-donors for laryngeal reinnervation are present (distal stump of PLN, ipsilateral and contralateral main branch of cervical loop) the RLN autoplasty performance must be maximally postponed because of low efficacy of such method of surgical laryngeal reinnervation.
The long-term impact of routine intraoperative nerve monitoring during thyroid and parathyroid surgery.
Snyder Samuel K,Sigmond Benjamin R,Lairmore Terry C,Govednik-Horny Cara M,Janicek Amy K,Jupiter Daniel C
Surgery
BACKGROUND:Despite widespread use of intraoperative nerve monitoring (IONM) as an adjunct to visual identification of the recurrent laryngeal nerve (RLN), published studies have shown little or no benefit. No long-term studies exist detailing the effect of experience gained from IONM on the rate of RLN injury. The aim of this study was to evaluate the impact of IONM feedback on surgical outcomes over time at a single institution. METHODS:We conducted retrospective analysis of prospectively gathered data for 1,936 patients including 3,435 nerves at risk between March 2004 and September 2011. Each RLN was analyzed for the specific, unilateral operative procedure that placed the nerve at risk of injury. The primary outcome measures included temporary vocal cord palsy and permanent vocal cord paralysis or paresis as determined by intraoperative loss of RLN function and postoperative laryngoscopy. Additional measures included instances where IONM assisted the surgeon's localization of the RLN. RESULTS:Of the 3,435 nerves at risk, 105 (3.06%) were injured, 4 had permanent paralysis (0.12%), and 7 had paresis (0.20%). Over time, a decrease in RLN injury was seen per successive operative year for thyroid lobectomy with paratracheal lymph node dissection with or without parathyroidectomy (odds ratio, 0.98; 95% confidence interval, 0.97-1.00; P = .04); the rate of nerve injury stabilized after 20 months of continued use of nerve monitoring. IONM particularly assisted the surgeon with identification of 108 nerves at risk (3.14%) with aberrant anatomy, and with identification of 236 nerves at risk (6.87%) during difficult dissections. CONCLUSION:With experience, routine use of IONM during thyroid and parathyroid operations significantly decreased the incidence of injury to the RLN for thyroid lobectomy with paratracheal lymph node dissection and provided useful assistance with RLN identification for 10% of nerves at risk.
10.1016/j.surg.2013.06.039
Morbidity following thyroid and parathyroid surgery: Results from key performance indicator assessment at a high-volume centre in New Zealand.
Lin Jin Xin,Wen Daniel,Sharma Avinash,van der Werf Bert,Martin Richard C W,Harman Richard
ANZ journal of surgery
BACKGROUND:Complications following thyroid/parathyroid surgery include recurrent laryngeal nerve (RLN) injury, hypocalcaemia and return to theatre for haematoma evacuation. Rates of these form the basis of key performance indicators (KPI). An endocrine database, containing results from 1997, was established at the North Shore Hospital in Auckland, New Zealand. We aimed to measure complication rates by procedure (thyroid and parathyroid), explore a temporal change in our unit and compare our results against international literature. METHODS:A retrospective review of the database between July 1997 and February 2020 was performed. The results for each KPI were analysed in total and over consecutive time periods. A review of the literature was carried out to find international complication rates for comparison. A cumulative sum (CUSUM) analysis was performed to give visual feedback on performance. RESULTS:There were 1062 thyroidectomies and 336 parathyroidectomies from July 1997 to February 2020. Thyroid surgery results found rates of temporary/permanent RLN injury of 1.9%/0.3%, temporary/permanent hypocalcaemia of 22.3/2.5%, and return to theatre for haematoma evacuation of 1.1%. Parathyroid surgery results were, temporary RLN injury of 0.8% (no permanent injury), temporary/permanent hypocalcaemia of 1.7%/0.4%, and return to theatre for haematoma evacuation of 0.3%. CUSUM analysis found KPI results to be comparable with international literature. CONCLUSION:Our unit's KPI results are comparable to published results in the literature. The use of this clinical database will help in future monitoring of performance and help drive improvement in the service. Embedding prospective data collection as routine practice allows for continuous improvement for the unit.
10.1111/ans.17099
[Functional recovery after recurrent laryngeal nerve injury on different electromyography thresholds during thyroid surgery].
Liu X L,Li C L,Zhao Y S,Sun H
Zhonghua wai ke za zhi [Chinese journal of surgery]
To discuss the functional recovery after recurrent laryngeal nerve injury (RLNI) on different electromyography thresholds during thyroid surgery. The prospective experimentally were induced in 12 acute recurrent laryngeal traction animals (porcine) from December 2014 to December 2015, the amplitude and latency of electromyography, even time course during RLNI and recovery of 24 recurrent laryngeal nerves(RLN) were continuous intraoperative neuromonitoring(IONM), including 12 RLN releasing traction after 50% amplitude decrease (AD) and other 12 RLN after 70% AD. The IONM data and postoperative laryngoscopy result of 1 119 thyroid cancer patients, involved 237 male and 882 female, aged 45.2 years in average, who underwent thyroidectomy in Department of Thyroid Surgery, China-Japan Union Hospital Affiliated to Jilin University from July to December in 2016 were analyzed retrospectively. The porcine model of traction lesion showed that the time of 50% AD was (59±4) s, latency increase (LI) was (8± 4)%, was recovered in 10 minutes; the time of 70% AD was (75±6)s, LI was (11±5)% , was recovered (43±23)% of baseline even during 20 minutes. Among the IONM of 1 632 recurrent laryngeal nerves in clinic, the mechanism of 64 RLNI is clear, including traction injury accounted for 62.5% (40/64), thermal injury was 12.5% (8/64), compression injury was 23.4% (15/64), clamp injury was 1.6% (1/64). When 50%≤AD <70% (8.8%), the rate of abnormal vocal fold movement (AVCM) was 8.8% (6/68), while AD≥70% (37.2%), the rate of AVCM was 37.2% (19/51), but LOS was 5/13. Releasing the injury before AD≥50% in surgery, is a more effective indicator to avoid postoperative AVCM and promote nerve function recovery.
10.3760/cma.j.issn.0529-5815.2017.11.007
Intraoperative nerve monitoring is associated with a lower risk of recurrent laryngeal nerve injury: A national analysis of 17,610 patients.
Kim Jina,Graves Claire E,Jin Chengshi,Duh Quan-Yang,Gosnell Jessica E,Shen Wen T,Suh Insoo,Sosa Julie A,Roman Sanziana A
American journal of surgery
BACKGROUND:Based on current evidence, the benefit of intraoperative nerve monitoring (IONM) in thyroid surgery is equivocal. METHODS:All patients who underwent planned thyroid surgery in the 2016-2018 ACS NSQIP procedure-targeted thyroidectomy dataset were included. Multivariable regression analyses were performed to examine the association between nerve monitoring and recurrent laryngeal nerve (RLN) injury while adjusting for patient demographics, extent of surgery, and perioperative variables. RESULTS:In total, 17,610 patients met inclusion criteria: 77.8% were female, and the median age was 52 years. IONM was used in 63.9% of cases. Of the entire cohort, 6.1% experienced RLN injury. Cases with IONM use had a lower rate of RLN injury compared to those that did not use IONM (5.7% vs. 6.8%, p = 0.0001). After adjustment, IONM was associated with reduced risk of RLN injury (OR 0.69, 95% CI 0.59-0.82, p < 0.0001). CONCLUSIONS:Nationally, IONM is used in nearly two thirds of thyroid surgeries. IONM is associated with a lower risk of recurrent laryngeal nerve injury.
10.1016/j.amjsurg.2020.10.013
Effect of remimazolam on intraoperative neuromonitoring during thyroid surgery: a case series.
Hayamizu Kengo,Chaki Tomohiro,Tachibana Shunsuke,Hirata Naoyuki,Yamakage Michiaki
Journal of anesthesia
Intraoperative neuromonitoring is widely used to prevent accidental injury during thyroid surgery. Anesthesia should be performed without muscle relaxant or agents with high muscle-relaxant potency. Remimazolam, a novel intravenous anesthetic, became available for clinical use in 2020. Remimazolam is an ultra-short-acting benzodiazepine with a very high clearance rate. However, there are very few data regarding its effect on currently used intraoperative neurological monitoring. Five patients underwent thyroid surgery using intraoperative recurrent laryngeal neuromonitoring. In all cases, intubation was performed after the administration of rocuronium. Anesthesia was maintained by continuous administration of remimazolam at the recommended dose and remifentanil, and no additional rocuronium or sugammadex was administered. Recurrent laryngeal nerve activity could be detected at the first stimulus after surgery was started, and monitoring continued thereafter. Intraoperative monitoring was performed without problems and all surgeries were completed without any complications. Anesthesia with remimazolam at the normal dose did not prolong the time to first positive electromyogram in patients undergoing thyroid surgery, and enables intraoperative recurrent laryngeal nerve monitoring to be performed without any serious perioperative adverse events. Remimazolam may provide a comparable quality of anesthesia to that of existing drugs for neuromonitoring during thyroid surgery.
10.1007/s00540-021-02955-3
Safety of high-current stimulation for intermittent intraoperative neural monitoring in thyroid surgery: A porcine model.
Lu I-Cheng,Chang Pi-Ying,Randolph Gregory W,Chen Hsiu-Ya,Tseng Kuang-Yi,Lin Yi-Chu,Chiang Feng-Yu,Wu Che-Wei
The Laryngoscope
OBJECTIVES:During monitored thyroidectomy, displacement of the recurrent laryngeal nerve (RLN) or vagus nerve (VN) in some complicated cases can increase the risk of injury. Although increasing the stimulus current can facilitate nerve mapping and localization, the safety of a high-current stimulus remains unknown. Therefore, this study evaluated the safety of a high-current stimulus in a porcine model. METHODS:Short-duration (1 minute), high-current (3, 5, 10, 15, 20, 25, and 30 mA at 4Hz) stimulus pulses were repeatedly applied to the RLN or VN in six anesthetized piglets. The safety of the high-current stimulus pulses was assessed in terms of hemodynamic stability during VN stimulation and in terms of nerve function integrity after VN and RLN stimulation. RESULTS:During VN stimulation with a high-current stimulus pulse, sinus rhythms in all six piglets showed stable heart rates, and mean arterial pressure was unaffected. High-current stimulation of the VN and the RLN did not affect electromyography amplitude or latency. CONCLUSION:This porcine study showed that applying a short-duration, high-current stimulus pulse to the VN or RLN during monitored thyroidectomy has no harmful effects. In clinical practice, a short duration of high-current stimulus can be applied to facilitate neural mapping, especially in patients with disoriented nerve positions. LEVEL OF EVIDENCE:NA. Laryngoscope, 128:2206-2212, 2018.
10.1002/lary.27086
A meta-analysis of intraoperative neuromonitoring of recurrent laryngeal nerve palsy during thyroid reoperations.
Sun Wei,Liu Jinhao,Zhang Hao,Zhang Ping,Wang Zhihong,Dong Wenwu,He Liang,Zhang Ting
Clinical endocrinology
BACKGROUND:The rate of recurrent laryngeal nerve (RLN) palsy, a common complication of thyroid surgery, is especially high in thyroid reoperations. The present meta-analysis assesses whether intraoperative neuromonitoring (IONM) reduces the prevalence of RLN palsy in thyroid reoperations. DESIGN AND METHODS:A systematic literature search was conducted in the PubMed, SCIE and Wan Fang databases for studies published up to 31 August 2016. All data were analysed using STATA (version 11) software. Publication bias was assessed using Begg's funnel plot and Egger's test, and sensitivity analysis was performed. RESULTS:Nine studies including 2436 at-risk nerves met the inclusion criteria. The results were presented as pooled relative risks (RRs) with 95% confidence intervals (CI). The overall RLN palsy rate was significantly lower in reoperations conducted with IONM than in those conducted without IONM (RR=0.434, 95% CI=0.206-0.916, P=.029). High heterogeneity was found (I =70.2%, P=.001). The rates of transient RLN palsy with and without IONM did not differ significantly (RR=0.607, 95% CI=0.270-1.366, P=.227). The heterogeneity was high (I =67.4%, P=.005). However, IONM was significantly associated with a reduction in permanent RLN palsy (RR=0.426, 95% CI=0.196-0.925, P=.031). No significant heterogeneity was found (I =13.7%, P=.325). Funnel plots for overall and transient RLN palsy showed a possible publication bias. CONCLUSIONS:Intraoperative neuromonitoring (IONM) is associated with a reduction in overall and permanent RLN palsy in thyroid reoperations. However, given the limited sample size and heterogeneity in this meta-analysis, further studies are required to confirm our preliminary findings.
10.1111/cen.13379
Risk factors for thyroid surgery-related unilateral vocal fold paralysis.
Chen Hung-Chun,Pei Yu-Cheng,Fang Tuan-Jen
The Laryngoscope
OBJECTIVES/HYPOTHESIS:We aimed to identify the risk factors for iatrogenic unilateral vocal fold paralysis (UVFP) caused by thyroid surgery, to allow the identification of patients requiring nerve-protection procedures and monitoring technologies. STUDY DESIGN:Retrospective case study in a medical center. METHODS:Patients who underwent thyroid surgery from April 2011 to February 2016 and who were diagnosed with UVFP by laryngoscopy and laryngeal electromyography were included. Patient demographics, types of surgery, and characteristics of the thyroid lesions were analyzed. RESULTS:Sixty (2.1%) of 2,815 patients who received thyroid surgery developed UVFP. The risk of UVFP was higher in patients over 60 years old (odds ratio, 1.89; 95% confidence interval, 1.01-3.26; P = .01). Involvement of the external branch of superior laryngeal nerve (EBSLN) occurred in 19 (31.7%) of the 60 UVFP patients, and was more likely to occurr in patients with diabetes mellitus (odds ratio, 14.19; 95% confidence interval, 3.80-52.94; P < .001). The incidence of UVFP and involvement of the EBSLN differed among surgery types, and was the highest among patients undergoing total thyroidectomy with neck dissection (TTND) (10/158, 6.3% and 5/158, 3.2%, respectively). CONCLUSIONS:The risk of thyroid surgery-related UVFP is higher in older patients. EBSLN involvement is more likely in patients with diabetes mellitus. TTND is associated with higher risks of UVFP and EBSLN injury than other types of surgery, implying the need of intraoperative nerve monitoring in these high-risk characteristics. LEVEL OF EVIDENCE:4 Laryngoscope, 129:275-283, 2019.
10.1002/lary.27336
Twenty-year experience of paediatric thyroid surgery using intraoperative nerve monitoring.
Schneider R,Machens A,Sekulla C,Lorenz K,Weber F,Dralle H
The British journal of surgery
BACKGROUND:There are few data on intermittent and continuous intraoperative nerve monitoring (IONM) during thyroidectomy in children. METHODS:All children aged 18 years or younger who had standard thyroid operations using intermittent or continuous IONM between January 1998 and December 2016 were included in the study. The impact of age and type of IONM on basal amplitude, latency and complications after thyroidectomy were assessed. RESULTS:A total of 504 children were included in the study. With continuous IONM, median basal amplitude and latency increased significantly with age, more on the left side (from 199 to 870 μV, and from 3·88 to 5·75 ms) than on the right (from 340 to 778 μV, and from 2·63 to 3·50 ms). Compared with intermittent IONM with needle electrode, continuous IONM with tube electrode resulted in an increase in median basal amplitude in children aged 13-18 years on both sides (from 675 to 778 μV on the right and from 450 to 870 μV on the left), and a decrease in median latency in all children older than 3 years: in children aged 4-6 years, from 4·20 to 3·00 ms on the right and from 6·10 to 4·63 ms on the left; in children aged 7-12 years, from 4·60 to 3·50 ms and from 6·00 to 5·25 ms respectively; and in children aged 13-18 years, from 4·60 to 3·50 ms and from 6·40 to 5·75 ms. Overall, wound infection, but not bleeding/haematoma or vocal fold palsy, affected younger children more: 3 per cent of children aged 3 years or less; 2 per cent of children aged 4-6 years; and 0 per cent of children aged over 6 years (P = 0·031). With continuous IONM, no wound infection, bleeding/haematoma or permanent vocal fold palsy was noted in any age group. CONCLUSION:Continuous IONM measures nerve electrophysiology more accurately than intermittent IONM during thyroidectomy in children.
10.1002/bjs.10792
Comparative Analysis of Phase Lag Entropy and Bispectral Index as Anesthetic Depth Indicators in Patients Undergoing Thyroid Surgery with Nerve Integrity Monitoring.
Seo Kwon Hui,Kim Kyung Mi,Lee Soo Kyung,John Hyunji,Lee Junsuck
Journal of Korean medical science
BACKGROUND:Most depth of anesthesia (DOA) monitors rely on the temporal characteristics of a single-channel electroencephalogram (EEG) and cannot provide spatial or connectivity information. Phase lag entropy (PLE) reflects DOA by calculating diverse connectivity from temporal patterns of phase relationships. The aim of this study was to compare the performance of PLE and bispectral index (BIS) monitors for assessing DOA during anesthesia induction, nerve integrity monitoring (NIM), and anesthesia emergence. METHODS:Thirty-five patients undergoing elective thyroid surgery with recurrent laryngeal nerve NIM received propofol and remifentanil via target-controlled infusion. After applying PLE and BIS monitors, propofol infusion was initiated at a calculated effect site concentration (Ce) of 2 μg/mL and then increased in 1-μg/mL Ce increments. After propofol Ce reached 5 μ/mL, a remifentanil infusion was begun, and anesthesia induction was considered complete. During NIM, PLE and BIS values were compared at a specific time points from platysma muscle exposure to subcutaneous tissue closure. PLE and BIS values were recorded continuously from preanesthetic state to full recovery of orientation; bias and limits of agreement between monitors were calculated. RESULTS:PLE and BIS values decreased progressively with increasing propofol Ce during anesthetic induction and increased by stages during emergence. The prediction probabilities of PLE and BIS for detecting propofol Ce changes were 0.750 and 0.756, respectively, during induction and 0.749 and 0.746, respectively, during emergence. No aberrant PLE or BIS values occurred during NIM. Correlation coefficients for BIS and PLE were 0.98 and 0.92 during induction and emergence, respectively. PLE values were significantly higher than BIS values at full recovery of orientation. Estimated bias between monitors was -4.16 ± 8.7, and 95% limits of agreement were -21.21 to 12.89. CONCLUSION:PLE is a reasonable alternative to BIS for evaluating consciousness and DOA during general anesthesia and during NIM. TRIAL REGISTRATION:Clinical Research Information Service Identifier: KCT0003490.
10.3346/jkms.2019.34.e151
An update on the status of nerve monitoring for thyroid/parathyroid surgery.
Lin Ho-Sheng,Terris David J
Current opinion in oncology
PURPOSE OF REVIEW:Recurrent laryngeal nerve (RLN) injury is one of the most common and serious complications associated with thyroid and parathyroid surgery. Although routine visual identification of the RLN is considered the current standard of care, the role of intraoperative neuromonitoring (IONM) of the RLN is more controversial. RECENT FINDINGS:Despite initial enthusiasm that IONM might substantially reduce the rate of RLN injury, most studies failed to show a significant difference in the rate of RLN injury when the use of IONM was compared with visualization of the RLN alone. However, a small number of investigators have reported statistically significant differences in the rates of nerve injury when IONM is used to augment visualization alone, particularly in certain high-risk situations. Despite a lack of conclusive data showing benefit, the use of IONM as an adjunct to visual identification of the RLN has gained increasing acceptance among surgeons. IONM remains an excellent tool to help verify the identity of the RLN, confirm its functional integrity, and pinpoint the site of nerve injury in the event of dysfunction. SUMMARY:The utility of IONM in reducing the rate of RLN injury is largely unproven and remains controversial. However, the use of IONM may be helpful in certain high-risk cases. Promising new technology, such as vagal nerve monitoring, may allow more real-time monitoring of the functional integrity of the RLN and allow the surgeon to react in a timely manner to evolving dysfunction in order to abort maneuvers that may risk definitive injury.
10.1097/CCO.0000000000000334
[Meta analysis of the real-time nerve monitoring in prevention of recurrent laryngeal nerve injury during thyroid surgery].
Li Keliang,Li Jinrang
Lin chuang er bi yan hou tou jing wai ke za zhi = Journal of clinical otorhinolaryngology, head, and neck surgery
OBJECTIVE:To compare the advantages and disadvantages of real time recurrent laryngeal nerve (RLN) monitoring and conventional exposure during thyroid operation by Meta analysis. METHOD:The published articles of randomized controlled clinical trials were searched in data bases to compare the therapeutic outcomes of using real-time RLN monitoring and conventional exposure in thyroid surgery. The quality of the searched original studies was assessed and the outcomes which are in line with the requirements were analyzed. RESULT:Six articles met the inclusion criteria, which contained 12,646 RLN in total. There were 5,535 cases in the RLN monitoring group and 7,111 cases in the conventional exposure group. The results of Meta analysis showed that: the transient injury rate of the RLN in the monitoring group (OR=0.60, 95% CI=0.49-0.73, P<0.01) was lower than that in the conventional exposure group, but the permanent injury rate of the RLN in two groups had no statistical difference (OR=0.90, 95 % CI= 0.57-1.40, P>0.05). The RLN identification rate also had no statistical difference between the two groups (OR=9.79, 95% CI=0.17-548. 64, P>0.05). CONCLUSION:The transient injury rate of the RLN is lower in the monitoring group than that in conventional exposure group, but the permanent injury rate and the RLN identification rate had no statistical difference between the two groups. The intraoperative nerve monitoring was useful in the prevention of the RLN injury in thyroid surgery.
Changes in electromyographic amplitudes but not latencies occur with endotracheal tube malpositioning during intraoperative monitoring for thyroid surgery: Implications for guidelines.
Barber Samuel R,Liddy Whitney,Kyriazidis Natalia,Cinquepalmi Matteo,Lin Brian M,Modi Rahul,Patricio Stephanie,Kamani Dipti,Belotti Carlo,Mahamad Sadhana,Lawson Bradley,Randolph Gregory W
The Laryngoscope
OBJECTIVES/HYPOTHESIS:During intraoperative neural monitoring (IONM) in thyroid and parathyroid surgery, endotracheal (ET) tube migration can result in a decrease in vocalis electromyographic (EMG) amplitude without a concordant latency elevation during stimulation of the recurrent laryngeal nerve (RLN). STUDY DESIGN:Retrospective review. METHODS:Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of the laryngeal nerves from January 2015 to December 2015. Recordings of vocalis EMG amplitudes and latencies with RLN stimulation were obtained with the neuromonitoring ET tube surface electrodes in optimal baseline position, with vertical displacement away from the vocalis, and with rotational change away from baseline. RESULTS:ET tube surface electrode EMG recordings were obtained with stimulation of seven left and three right RLNs in a total of 10 patients. Mean vocalis EMG amplitudes were reduced with vertical displacement 1 and 2 cm both inferior and superior to baseline and with rotational change (45° and 90° clockwise and counterclockwise, 180°), although amplitude change with 45° clockwise and 180° rotation did not meet statistical significance. Mean EMG latency values did not change significantly from baseline with either rotation or vertical displacement of the ET tube. CONCLUSIONS:An isolated decrease in EMG amplitude without concordant latency elevation should warrant re-evaluation of ET tube position during thyroid and parathyroid surgery and is in contrast to a combined event, with both EMG amplitude decrease and concordant latency increase, which is more suggestive of a true neuropraxic injury. LEVEL OF EVIDENCE:4. Laryngoscope, 127:2182-2188, 2017.
10.1002/lary.26392
Comparison of EMG signals recorded by surface electrodes on endotracheal tube and thyroid cartilage during monitored thyroidectomy.
Chiang Feng-Yu,Lu I-Cheng,Chang Pi-Ying,Dionigi Gianlorenzo,Randolph Gregory W,Sun Hui,Lee Kang-Dae,Tae Kyung,Ji Yong Bae,Kim Sung Won,Lee Hyoung Shin,Wu Che-Wei
The Kaohsiung journal of medical sciences
A variety of electromyography (EMG) recording methods were reported during intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) in thyroid surgery. This study compared two surface recording methods that were obtained by electrodes on endotracheal tube (ET) and thyroid cartilage (TC). This study analyzed 205 RLNs at risk in 110 patients undergoing monitored thyroidectomy. Each patient was intubated with an EMG ET during general anesthesia. A pair of single needle electrode was inserted obliquely into the TC lamina on each side. Standard IONM procedure was routinely followed, and EMG signals recorded by the ET and TC electrodes at each step were compared. In all nerves, evoked laryngeal EMG signals were reliably recorded by the ET and TC electrodes, and showed the same typical waveform and latency. The EMG signals recorded by the TC electrodes showed significantly higher amplitudes and stability compared to those by the ET electrodes. Both recording methods accurately detected 7 partial loss of signal (LOS) and 2 complete LOS events caused by traction stress, but only the ET electrodes falsely detected 3 LOS events caused by ET displacement during surgical manipulation. Two patients with true complete LOS experienced temporary RLN palsy postoperatively. Neither permanent RLN palsy, nor complications from ET or TC electrodes were encountered in this study. Both electrodes are effective and reliable for recording laryngeal EMG signals during monitored thyroidectomy. Compared to ET electrodes, TC electrodes obtain higher and more stable EMG signals as well as fewer false EMG results during IONM.
10.1016/j.kjms.2017.06.014
Universal Use of Intraoperative Nerve Monitoring by Recently Fellowship-Trained Thyroid Surgeons is Common, Associated with Higher Surgical Volume, and Impacts Intraoperative Decision-Making.
Marti Jennifer L,Holm Tammy,Randolph Gregory
World journal of surgery
INTRODUCTION:The value of routine use of intraoperative recurrent laryngeal nerve monitoring (IONM) in thyroid surgery is controversial. We analyzed the practices of recently fellowship-trained thyroid surgeons from two diverging surgical backgrounds with respect to IONM. We hypothesized that the majority of recently trained surgeons would use IONM, and that it would potentially influence their operative procedure. METHODS:A 21-question survey was sent to 56 fellowship-trained endocrine and head and neck surgeons who completed fellowships accredited by the American Association of Endocrine Surgeons or American Head and Neck Society within the past 10 years, examining the demographics of respondents, and details of IONM practice. Groups were compared using the Fisher exact and χ (2) tests. RESULTS:The response rate for the survey was 76 % (42/56). Overall, 95 % use IONM for some or all of their cases. Sixty percent (n = 25) of respondents always use IONM during thyroid surgery, 36 % (n = 15) use it selectively, and 5 % (n = 2) never use it. We compared respondents who always use IONM (n = 25), to those who selectively or never use it (n = 17). Exposure to IONM during residency or fellowship did not influence use (p = 0.99). However, higher-volume surgeons were more likely to always use IONM (p = 0.036). Among users of IONM, the most common reason given for use was increased surgeon confidence (55 %) and improved safety (54 %). Over 90 % of respondents found reoperative cases and preoperative vocal cord paralysis to be indications for IONM. Among those who always used IONM, 64 % would alter extent of surgery based on IONM findings, compared to only 27 % of selective users. CONCLUSIONS:A survey of recently trained endocrine and head and neck surgeons reveals that the vast majority (95 %) of these surgeons commonly use IONM during thyroid surgery. IONM was more commonly used by higher-volume surgeons. Routine users were more likely to modify surgery based on nerve integrity (i.e., not complete a total thyroidectomy if the nerve loses conduction signal).
10.1007/s00268-015-3238-7
Routine Intraoperative Neuromonitoring of the Recurrent Laryngeal Nerve to Facilitate Complete Resection and Ensure Safety in Thyroid Cancer Surgery.
Wu Si-Yuan,Shen Hung-Yuan,Duh Quan-Yang,Hsieh Chung-Bao,Yu Jyh-Cherng,Shih Ming-Lang
The American surgeon
Routine use of intraoperative neuromonitoring (IONM) in thyroid cancer surgery is controversial. We aimed to investigate whether it improves the completeness of thyroidectomy and ensures safety. This retrospective study included 380 thyroid cancer patients who underwent thyroidectomy, by one surgeon, between July 2006 and November 2015. Patients were grouped according to the surgeon's adaptation of IONM, as follows: none (period 1; n = 92), early (period 2; n = 141), and late (period 3; n = 147). The operative time and rates of vocal cord palsy were determined. Surgical completeness was assessed by technetium-99m imaging of the thyroid remnant and serum thyroglobulin measurement before ablation. The rate of recurrent laryngeal nerve (RLN) palsy showed a decreasing trend over time. No permanent RLN palsies occurred in nerves not invaded by tumor after routine IONM was introduced. Technetium-99m uptake (periods 1-3, 0.62 vs 0.32 vs 0.20; < 0.01) and thyroglobulin levels (periods 1 and 2, 37.93 vs 8.98 ng/mL, respectively; = 0.034; period 3, 9.10 ng/mL) progressively decreased. The mean thyroglobulin level dropped significantly after introduction of routine IONM. We conclude that routine IONM during thyroid cancer surgery improves surgical completeness and might prevent permanent RLN palsy over time.
Role of intraoperative neuromonitoring of recurrent laryngeal nerve in thyroid and parathyroid surgery.
Ling Yuwei,Zhao Jing,Zhao Ye,Li Kaifu,Wang Yajun,Kang Hua
The Journal of international medical research
OBJECTIVE:To investigate whether intraoperative neuromonitoring (IONM) has a significant advantage in reducing the incidence of recurrent laryngeal nerve (RLN) injury. METHODS:Patients who underwent thyroid and parathyroid surgery from October 2012 to December 2017 at the Center for Thyroid and Breast Surgery of Xuanwu Hospital were retrospectively analyzed. They were divided into the IONM group and visualization alone group (VA group) according to whether IONM was used. RESULTS:In total, 1696 nerves at risk of injury (IONM group, n = 1104; VA group, n = 592) were included in the analysis. Among the high-risk nerves, permanent damage occurred in no cases in the IONM group but in one case in the VA group. Because the higher proportion of central lymph node metastasis caused difficulties in central cervical lymph node dissection and identification of the RLN, the patients undergoing lateral cervical lymph node dissection in the VA group had a significantly higher risk of postoperative RLN injury (11.76% vs. 0.00%). CONCLUSION:IONM technology has advantages in protection of the RLN, especially in high-risk nerves and patients with a high proportion of central lymph node metastasis who require central and lateral cervical lymph node dissection.
10.1177/0300060520952646
Continuous Vagal Nerve Monitoring is Dangerous and Should not Routinely be Done During Thyroid Surgery.
Terris David J,Chaung Katrina,Duke William S
World journal of surgery
INTRODUCTION:Laryngeal nerve monitoring has been increasingly embraced as a mechanism for mitigating the risk of nerve damage during thyroid and parathyroid surgery. Vagal nerve monitoring has recently been introduced as a potentially increased level of nerve integrity scrutiny. We sought to define the risks and benefits of this technology in a prospective analysis of a series of patients undergoing neck endocrine surgery. SETTING:High-volume academic endocrine surgery practice. METHODS:A prospective, non-controlled trial of continuous vagal nerve monitoring (CVNM) in a projected cohort of 20 non-randomly selected patients undergoing thyroid and parathyroid surgery was planned. A commercially available nerve monitoring system with automatic periodic stimulation was utilized for both laryngeal nerve monitoring and CVNM. Demographic data were obtained, and outcome variables included surgical procedures performed, pathology, complications, incremental time required to achieve CVNM, and benefits of monitoring and stimulation. RESULTS:The patient accrual was aborted after 9 surgeries (12 nerves monitored) because of two serious adverse events (hemodynamic instability and reversible vagal neuropraxia attributable to the monitoring apparatus). No other complications occurred. The time to establish monitoring ranged from 3 to 26 min, with a median of 6 min (representing 2.9-12.2 % of the total surgical procedural time). The stimulation clamp became dislodged 11 times in 5 cases and was replaced in 7 of those instances. Benefits of CVNM included recognition of reduced amplitude and increased nerve latency in two patients. CONCLUSIONS:We report the first evidence that CVNM may cause serious patient harm. This novel approach is invasive and threatens patient safety. Although it may occasionally provide meaningful information, the risk-benefit ratio does not favor widespread adoption.
10.1007/s00268-015-3139-9
Intraoperative neuromonitoring versus visual nerve identification for prevention of recurrent laryngeal nerve injury in adults undergoing thyroid surgery.
The Cochrane database of systematic reviews
BACKGROUND:Injuries to the recurrent inferior laryngeal nerve (RILN) remain one of the major post-operative complications after thyroid and parathyroid surgery. Damage to this nerve can result in a temporary or permanent palsy, which is associated with vocal cord paresis or paralysis. Visual identification of the RILN is a common procedure to prevent nerve injury during thyroid and parathyroid surgery. Recently, intraoperative neuromonitoring (IONM) has been introduced in order to facilitate the localisation of the nerves and to prevent their injury during surgery. IONM permits nerve identification using an electrode, where, in order to measure the nerve response, the electric field is converted to an acoustic signal. OBJECTIVES:To assess the effects of IONM versus visual nerve identification for the prevention of RILN injury in adults undergoing thyroid surgery. SEARCH METHODS:We searched CENTRAL, MEDLINE, Embase, ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 21 August 2018. We did not apply any language restrictions. SELECTION CRITERIA:We included randomised controlled trials (RCTs) comparing IONM nerve identification plus visual nerve identification versus visual nerve identification alone for prevention of RILN injury in adults undergoing thyroid surgery DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles and abstracts for relevance. One review author carried out screening for inclusion, data extraction and 'Risk of bias' assessment and a second review author checked them. For dichotomous outcomes, we calculated risk ratios (RRs) with 95% confidence intervals (CIs). For continuous outcomes, we calculated mean differences (MDs) with 95% CIs. We assessed trials for certainty of the evidence using the GRADE instrument. MAIN RESULTS:Five RCTs with 1558 participants (781 participants were randomly assigned to IONM and 777 to visual nerve identification only) met the inclusion criteria; two trials were performed in Poland and one trial each was performed in China, Korea and Turkey. Inclusion and exclusion criteria differed among trials: previous thyroid or parathyroid surgery was an exclusion criterion in three trials. In contrast, this was a specific inclusion criterion in another trial. Three trials had central neck compartment dissection or lateral neck dissection and Graves' disease as exclusion criteria. The mean duration of follow-up ranged from 6 to 12 months. The mean age of participants ranged between 41.7 years and 51.9 years.There was no firm evidence of an advantage or disadvantage comparing IONM with visual nerve identification only for permanent RILN palsy (RR 0.77, 95% CI 0.33 to 1.77; P = 0.54; 4 trials; 2895 nerves at risk; very low-certainty evidence) or transient RILN palsy (RR 0.62, 95% CI 0.35 to 1.08; P = 0.09; 4 trials; 2895 nerves at risk; very low-certainty evidence). None of the trials reported health-related quality of life. Transient hypoparathyroidism as an adverse event was not substantially different between intervention and comparator groups (RR 1.25; 95% CI 0.45 to 3.47; P = 0.66; 2 trials; 286 participants; very low-certainty evidence). Operative time was comparable between IONM and visual nerve monitoring alone (MD 5.5 minutes, 95% CI -0.7 to 11.8; P = 0.08; 3 trials; 1251 participants; very low-certainty evidence). Three of five included trials provided data on all-cause mortality: no deaths were reported. None of the trials reported socioeconomic effects. The evidence reported in this review was mostly of very low certainty, particularly because of risk of bias, a high degree of imprecision due to wide confidence intervals and substantial between-study heterogeneity. AUTHORS' CONCLUSIONS:Results from this systematic review and meta-analysis indicate that there is currently no conclusive evidence for the superiority or inferiority of IONM over visual nerve identification only on any of the outcomes measured. Well-designed, executed, analysed and reported RCTs with a larger number of participants and longer follow-up, employing the latest IONM technology and applying new surgical techniques are needed.
10.1002/14651858.CD012483.pub2
Bilateral recurrent laryngeal nerve injury in a specialized thyroid surgery unit: would routine intraoperative neuromonitoring alter outcomes?
Sarkis Leba M,Zaidi Nisar,Norlén Olov,Delbridge Leigh W,Sywak Mark S,Sidhu Stan B
ANZ journal of surgery
BACKGROUND:Bilateral recurrent laryngeal nerve (RLN) palsy following total thyroidectomy is a rare complication, however, poses significant morbidity to the patient when it does occur. The purpose of this paper was to determine the incidence of bilateral RLN palsy in a specialized thyroid unit and determine whether the routine use of intraoperative nerve monitoring (IONM) would alter the outcome. METHODS:This is a retrospective review of prospectively gathered data. A total of 7406 patients underwent total thyroidectomy at the University of Sydney Endocrine Surgical Unit between January 1990 and February 2014. IONM was utilized on a selective basis and we sought to assess whether IONM would have altered outcome in those patients who developed bilateral RLN palsy. RESULTS:Of the 7406 patients who underwent total thyroidectomy, seven patients (0.09%) developed bilateral RLN palsy during the study period. There was one permanent RLN palsy (0.01%) and routine IONM may have prevented one death and altered the outcome in two of the seven patients. CONCLUSION:Bilateral RLN palsy is a rare entity occurring in one out of 1000 cases in a specialized thyroid unit. IONM may facilitate the decision to pursue delayed surgery where the signal is lost on the first surgical side and has the potential to avoid bilateral RLN palsy following total thyroidectomy.
10.1111/ans.12980
Intermittent intraoperative nerve monitoring in thyroid reoperations: Preliminary results of a randomized, single-surgeon study.
Hei Hu,Zhou Bin,Qin Jianwu,Song Yongping
Head & neck
BACKGROUND:The purpose of this study was to evaluate whether intermittent intraoperative nerve monitoring (IONM) could reduce the incidence of recurrent laryngeal nerve (RLN) paralysis in thyroid reoperations. METHODS:Enrolled patients were randomly assigned into the nerve integrity monitor (NIM) group and the control group. RESULTS:The incidence of temporary RLN paralysis and permanent RLN paralysis was 12.2% and 4.9% in the NIM group compared with 7.0% and 2.3% in the control group (p = .658 and p = .966, respectively). The incidence of surgeon-related paralysis, tumor-related paralysis, and scar-related paralysis was 4.9%, 7.3%, and 4.9% in the NIM group compared with 4.7%, 2.3%, and 2.3% in the control group, respectively (p = 1, p = .575, and p = .966, respectively). CONCLUSION:Intermittent IONM could not provide additional benefits to reduce the incidence of temporary RLN paralysis and permanent RLN paralysis in thyroid reoperations. It could not reduce the incidence of paralysis caused by unintentional injuries. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1993-E1997, 2016.
10.1002/hed.24365
Intraoperative nerve monitoring in thyroid surgery.
Polat Ayfer Kamali,Lap Gokhan,Ozbalci Selcuk,Karabulut Kagan,Gungor Bulent,Polat Cafer,Erzurumlu Kenan
Annali italiani di chirurgia
BACKGROUND:Nerve injury is one of the specific complications of thyroid surgery despite many advances in surgical technique. The recurrent laryngeal nerve (RLN) and the external branch of superior laryngeal nerve are the nerves at risk during thyroid surgery (1). Morbidity related to recurrent laryngeal nerve injury varies from changes in voice quality to severe dyspnea requiring tracheal intubation or tracheostomy. To minimize the risk of nerve injury, intraoperative nerve monitoring (IONM) being suggested as a tool for helping visual control for RLN has gained significant interest in recent years (1,2). We aimed to determine the effectiveness of nerve monitoring during thyroid surgery and to provide a clinical experience. MATERIALS AND METHODS:This study was performed from June 2010 to June 2012. We prospectively evaluated 94 patients who had thyroid surgery with or without nerve monitoring. Of those patients 48 were in monitored group (M) and 46 were in unmonitored group (UM). RESULTS:The mean age was 48 (27-76) in M group and 52 (73-17) in UM. There was only one patient had transient hoarseness in M group and also one patient had transient hoarseness in UM group. One each in both groups had persistent hoarseness. No patients experienced airway problem. Operation time was significantly shorter in M group (p<0.001). CONCLUSIONS:Use of a nerve monitoring system does not substitute for careful dissection and visual identification of nerves, but monitoring can assist the surgeon in identifying the RLN anatomic variability and may decrease the operation time during thyroid surgery.
Intraoperative nerve monitoring in thyroid surgery: analysis of United Kingdom registry of endocrine and thyroid surgery database.
Abdelhamid A,Aspinall S
The British journal of surgery
BACKGROUND:Intraoperative nerve monitoring (IONM) is used increasingly in thyroid surgery to prevent recurrent laryngeal nerve (RLN) injury, despite lack of definitive evidence. This study analysed the United Kingdom Registry of Endocrine and Thyroid Surgery (UKRETS) to investigate whether IONM reduced the incidence of RLN injury. METHODS:UKRETS data were extracted on 28 July 2018. Factors related to risk of RLN palsy, such as age, sex, retrosternal goitre, reoperation, use of energy devices, extent of surgery, nodal dissection and IONM, were analysed. Data with missing entries for these risk factors were excluded. Outcomes of patients who had preoperative and postoperative laryngoscopy were analysed. RESULTS:RLN palsy occurred in 4.9 per cent of thyroidectomies. The palsy was temporary in 64.6 per cent and persistent in 35.4 per cent of patients. In multivariable analysis, IONM reduced the risk of RLN palsy (odds ratio (OR) 0.63, 95 per cent confidence interval (CI) 0.54 to 0.74, P < 0.001) and persistent nerve palsy (OR 0.47, 0.37 to 0.61, P < 0.001). Outpatient laryngoscopy was also associated with a reduced incidence of RLN palsy (OR 0.50, 0.37 to 0.67, P < 0.001). Bilateral RLN palsy occurred in 0.3 per cent. Reoperation (OR 12.30, 2.90 to 52.10, P = 0.001) and total thyroidectomy (OR 6.52, 1.50 to 27.80; P = 0.010) were significantly associated with bilateral RLN palsy. CONCLUSION:The use of IONM is associated with a decreased risk of RLN injury in thyroidectomy. These results based on analysis of UKRETS data support the routine use of RLN monitoring in thyroid surgery.
10.1093/bjs/znaa081
Recurrent Laryngeal Nerve Injury After Thyroid Surgery: An Analysis of 11,370 Patients.
Gunn Alexander,Oyekunle Taofik,Stang Michael,Kazaure Hadiza,Scheri Randall
The Journal of surgical research
BACKGROUND:Recurrent laryngeal nerve (RLN) injury is a well-known, potentially serious complication of thyroid surgery. We investigated factors associated with RLN injury during thyroid surgery using a multi-institutional data set. MATERIALS AND METHODS:Patients who underwent either lobectomy or total thyroidectomy were abstracted from the American College of Surgeons National Surgical Quality Improvement Program thyroidectomy-specific database (2016-2017). Baseline and operative factors associated with RLN injury ≤30 d of surgery were analyzed using bivariate and multivariate methods. Secondary complications of interest included unplanned reintubation and hypocalcemia. RESULTS:RLN injury occurred in 6.0% (n = 677) of the 11,370 patients included in the study. The RLN injury rate varied significantly based on the primary indication for surgery, from 4.3% in patients undergoing surgery for a single nodule to 9.0% in patients undergoing surgery for differentiated cancer (P < 0.01). RLN injury occurred more often in thyroidectomies than lobectomies (6.9% versus 4.3%, P < 0.01) and in surgeries without intraoperative nerve monitoring (6.5% versus 5.6%, P = 0.01). After multivariate adjustment, RLN injury was independently associated with age ≥65 y [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.3-2.0], total thyroidectomy (OR = 1.4, 95% CI 1.1-1.6), and diagnosis of thyroid malignancy (OR = 2.1, 95% CI = 1.6-2.7) (all P < 0.001) but not intraoperative RLN monitoring (OR = 0.9, 95% CI = 0.7-1.0, P = 0.06). CONCLUSIONS:In this large multi-institutional study, RLN injury ≤30 d of surgery occurred in nearly 6% of thyroid surgeries. This comprehensive analysis of RLN injury can be used to guide informed consent discussions and aid surgeons in identifying candidates who may be at higher risk for injury.
10.1016/j.jss.2020.05.017
Intraoperative nerve monitoring is used routinely by a significant majority of head and neck surgeons in thyroid surgery and impacts on extent of surgery-Survey of the American Head and Neck Society.
Ritter Amit,Ganly Ian,Wong Richard J,Randolph Gregory W,Shpitzer Thomas,Bachar Gideon,Mizrachi Aviram
Head & neck
BACKGROUND:The data on the advantages of intraoperative nerve monitoring (IONM) during thyroid surgeries is inconsistent. Our objective was to study the patterns of use of IONM in thyroid surgery among American Head and Neck Society (AHNS) members. METHOD:A web-based survey was e-mailed to all members of the AHNS. RESULTS:A total of 275 surgeons completed the survey. Seventy-two percent reported using IONM routinely. Routine use of IONM was associated with longer period in practice. Twenty-one percent only used IONM selectively in high-risk cases. Most surgeons would consider aborting the procedure in cases of loss of signal without continuing to the contralateral side. Finally, only 19% of surgeons attempt to identify the external branch of the superior laryngeal nerve (EBSLN). CONCLUSIONS:The majority of AHNS surgeons routinely use IONM during thyroid surgery as a real-time decision-making tool. However, IONM for preservation of the EBSLN is underutilized.
10.1002/hed.26093
Learning Curve for Using Intraoperative Neural Monitoring Technology of Thyroid Cancer.
Zhao Ning,Bai Zhigang,Teng Changsheng,Zhang Zhongtao
BioMed research international
We investigated the learning curve for using intraoperative neural monitoring technology in thyroid cancer, with a view to reducing recurrent laryngeal nerve injury complications. Radical or combined radical surgery for thyroid cancer was performed in 82 patients with thyroid cancer and 147 recurrent laryngeal nerves were dissected. Intraoperative neural monitoring technology was applied and the "four-step method" used to monitor recurrent laryngeal nerve function. When the intraoperative signal was attenuated by more than 50%, recurrent laryngeal nerve injury was diagnosed, and the point and causes of injury were determined. The time required to identify the recurrent laryngeal nerve was 0.5-2 min and the injury rate was 2.7%; injuries were diagnosed intraoperatively. Injury most commonly occurred at or close to the point of entry of the nerve into the larynx and was caused by stretching, tumor adhesion, heat, and clamping. The groups are divided in chronological order; a learning curve for using intraoperative neural monitoring technology in thyroid cancer surgery was generated based on the time to identify the recurrent laryngeal nerve and the number of cases with nerve injury. The time to identify the recurrent laryngeal nerve and the number of injury cases decreased markedly with increasing patient numbers. There is a clear learning curve in applying intraoperative neural monitoring technology to thyroid cancer surgery; appropriate use of such technology aids in the protection of the recurrent laryngeal nerve.
10.1155/2019/8904736
Role of intraoperative recurrent laryngeal nerve monitoring for pediatric thyroid surgery: Comparative analysis.
Ritter Amit,Hod Roy,Reuven Yonatan,Shpitzer Thomas,Mizrachi Aviram,Raveh Eyal,Bachar Gideon
Head & neck
BACKGROUND:The data on the advantages of intraoperative nerve monitoring (IONM) during pediatric thyroid surgeries are limited. We aimed to study the role of IONM by comparing between children who underwent thyroid surgery with and without IONM. METHODS:A retrospective study of all children who underwent thyroid surgery between 2001 and 2019. RESULTS:The study included 113 patients with 183 recurrent laryngeal nerve (RLN) at risk. Transient paralysis rate was more than 5-fold lower in the IONM group compared to the control group (1.5% vs 8%; P = .114). Permanent paralysis was documented only in the control group (2.5% vs 0%; P = .552). Children <10 years and those who underwent central neck dissection had significantly higher rates of RLN injury. CONCLUSIONS:IONM was associated with decreased rate of RLN injury during pediatric thyroid surgery and should be considered especially in children under 10 years of age and those undergoing concomitant central neck dissection.
10.1002/hed.26544
Pre-Prototype Stimulating and Recording Endotracheal Tube for Continuous Monitoring of the Recurrent Laryngeal Nerve During Thyroid Surgery.
Journal of investigative surgery : the official journal of the Academy of Surgical Research
INTRODUCTION:Continuous intraoperative neural monitoring (C-IONM) is a promising technology used to decrease recurrent laryngeal nerve (RLN) damage during thyroid surgery. However, C-IONM use is limited due to its challenging application. C-IONM requires dissection of the carotid sheath and placement of an electrode around the vagus nerve (VN). In our study, we simultaneously stimulated and monitored the proximal RLN trans-tracheally using surface electrodes that were positioned solely on the endotracheal tube. METHODS:We described the design, implementation, and testing of a pre-prototype, combined stimulating and recording endotracheal tube (SRET) that continually delivered current from tube edge, and tested the function of the RLN at the vocal cords (VC). The SRET was tested in vivo on 10 RLNs using 5 pigs as animal models. RESULTS:The SRET was capable of the following, delivery of continuous trans-tracheal stimulation to the proximal RLN, continuous trans-tracheal stimulation-induced VC movement, and standard ipsilateral RLN biphasic waveforms with latency and amplitude; and recording evoked responses were recorded in the ipsilateral RLN. CONCLUSION:The pre-prototype SRET represents a possible advancement in technology because it simplified the C-IONM. Thus, the SRET provides a minimally invasive, alternative application to the C-IONM vagal nerve cuff electrodes.
10.1080/08941939.2020.1734693