Superior Laryngeal Nerve Injury Research Articles

Voice Changes Without Laryngeal Nerve Alterations After Thyroidectomy: The Need For Prospective Trials - A Review Study.

Thyroidectomy is a commonly performed surgical procedure that is offered for different thyroid pathologies. The most frequent complication after total thyroidectomy is transient or permanent hypoparathyroidism followed by transient or permanent recurrent laryngeal nerve palsy. Patients may experience voice impairment despite intact laryngeal nerve function. These patients are of special interest because they experience subjective symptoms which are difficult to measure and therefore to treat. The Voice Handicap Index (VHI) and VHI-10 are the most commonly used subjective questionnaires. Their results correlate with objective findings. Female sex, in particular after menopause, is a dominant factor for developing voice impairment after thyroidectomy. The extent of neck surgery and the weight and volume of the removed thyroid correlates directly with both objective and subjective voice impairment after surgery. Videolaryngostroboscopy should be considered to examine vocal cord pathologies in this patient group. Surprisingly, there are no studies showing that speech and voice therapy are beneficial for patients with voice alterations but with intact laryngeal nerves. While recurrent laryngeal nerve (RLN) paralysis can be evaluated by objective exams postoperatively, we are still left with the issue of possible partial or complete external branch of superior laryngeal nerve (EBSLN) injury. It is therefore quite difficult to segregate neural (RLN and EBSLN) and non-neural voice change populations, regardless of the method of literature evaluation. Perhaps patients' perspectives on how they experience voice functionality should play a superior role in deciding which patients should be investigated further with laryngoscopy, acoustic or perceptual analysis, and which patients should be offered treatment.

Neurophysiology of the Superior Laryngeal Nerve in an In Vivo Rat Model.

The superior laryngeal nerve (SLN) is fundamental in laryngeal sensation, cough reflex, and pitch control. SLN injury has substantial consequences including altered sensation, aspiration, and dysphonia. To date, in vivo measurement of the SLN remains elusive. The purpose of this study was to assess the feasibility of recording motor and sensory evoked potentials in a rat SLN model. Twenty-two rat hemi-laryngeal preparations (n = 11) were obtained from 4-month-old Sprague-Dawley rats and included in this study. Compound motor action potentials (CMAPs) and motor unit number estimation (MUNE) were calculated by stimulating the SLN at the point of medial extension near the carotid artery and by placing a recording electrode on the cricothyroid muscle. Sensory response was determined through stimulation of the SLN and laryngoscopic visualization of a laryngeal adductor reflex (LAR). SLN and cricothyroid muscle cross-sections were stained and histologic morphometrics were quantified. Laryngeal evoked potentials were successfully obtained in all trials. Mean CMAP latency and negative durations were 0.99 ± 0.57 ms and 1.49 ± 0.57 ms, respectively. The median MUNE was 2.06 (IQR 1.88, 3.51). LAR was induced with a mean intensity of 0.69 ± 0.20 mV. Mean axon count, myelin thickness, and g-ratio were 681 ± 192.2, 1.72 ± 0.26, and 0.45 ± 0.04, respectively. This study demonstrates the feasibility of recording evoked response potentials following SLN stimulation. We hypothesize that this work will provide a tractable animal model to study changes in laryngeal sensation and cricothyroid motor function with aging, neurodegenerative disease, aspiration, or nerve injury. NA Laryngoscope, 134:1778-1784, 2024.

Assessment of different classification systems for predicting the risk of superior laryngeal nerve injury during thyroid surgery: a prospective cohort study.

A multitude of anatomical variations have been noted in the external branch of the superior laryngeal nerve (EBSLN). In this study, intraoperative neuromonitoring (IONM) was used to assess the potential value of the different classical EBSLN classifications for predicting the risk of EBSLN injury. In total, 136 patients with thyroid nodules were included in this prospective cohort study, covering 242 nerves at risk (NAR). The EBSLN was identified by observing the cricothyroid muscle twitch and/or typical electromyography (EMG) biphasic waveform. The EBSLNs were classified by Cernea classification, Kierner classification, and Friedman classification, respectively. The EMG parameters and outcomes of vocal acoustic assessment were recorded. The distribution of Cernea, Kiernea, and Friedman subtypes were, respectively, Cernea 1 (40.9%), Cernea 2A (45.5%), Cernea 2B (10.7%), Kierner 1 (40.9%), Kierner 2 (45.5%), Kierner 3 (10.7%), Kierner 4 (2.9%) and Friedman 1 (15.7%), Friedman 2 (33.9%), Friedman 3 (50.4%). The amplitudes of EBSLN decreased significantly after superior thyroid pole operation, respectively, in Cernea 2A (193.7 vs. 226.6μV, P=0.019), Cernea 2B (185.8 vs. 221.3μV, P=0.039), Kierner 2 (193.7vs. 226.6μV, P=0.019), Kierner 3 (185.8 vs. 221.3μV, P=0.039), Kierner 4 (126.8vs. 226.0μV, P=0.015) and Friedman type 2 (184.8 vs. 221.6μV, P=0.030). There were significant differences in Fmax and Frange for Cernea 2A (P=0.001, P=0.001), 2B (P=0.001, P=0.038), Kierner 2 (P=0.001), Kierner 3 (P=0.001, P=0.038), and Friedman 2 (P=0.004, P=0.014). In the predictive efficacy of EBSLN injury, the Friedman classification showed higher accuracy (69.8% vs. 44.3% vs. 45.0%), sensitivity (19.5% vs. 11.0% vs. 14.0%), and specificity (95.6% vs. 89.9% vs. 89.9%) than the Cernea and Kierner classifications. However, the false negative rate of Friedman classification was significantly higher than other subtypes (19.5% vs. 11.0% vs. 14.0%). Cernea 2A and 2B; Kierner 2, 3, and 4; and Friedman 2 were defined as the high-risk subtypes of EBSLN. The risk prediction ability of the Friedman classification was found to be superior compared to other classifications.

Effect of mouse nerve growth factor combined with the exposure of the external branch of superior laryngeal nerve on voice changes after thyroidectomy: a prospective non-randomized controlled trial.

The superior laryngeal nerve (SLN) injury may also affect vocal fold function and voice quality. It is efficient yet simple approach to expose the external branch of the superior laryngeal nerve (EBSLN). Neurotrophic agent mouse nerve growth factor (mNGF) to treat patients after thyroid surgery, and found it had significant efficacy in improving the voice of patients. However, the potential effectiveness and safety of mNGF combined with EBSLN were unclear. In this study, 96 patients who suffered from hoarseness after thyroidectomy at Hangzhou First People's Hospital between January 2018 and October 2019 were screened and divided into the control group and the observation group by patients' choice. In the control group, the SLN was not exposed. In the observation group, the SLN was exposed. The mNGF treatment was administered for observation group once a day at 20 µg each time for 4 weeks. The data of acoustic voice indicators was analysis by univariate analyses. Patients in both groups were followed up for more than 6 months. The rate of SLN damage was compared between two groups. The baseline clinical characteristics of the two groups showed no statistic difference. The results showed that the fundamental frequency was significantly lower 1 month after surgery than 3 days after surgery in both groups. The fundamental frequency perturbation, shimmer, maximum phonation time, highest fundamental frequency, and dysphonia severity index in 1 month after surgery were significantly higher than they were 3 days after surgery (all P<0.001). There was no significant difference in the postoperative harmonic-to-noise ratio between the 2 groups (P=0.426). MNGF combined with the exposure and protection of the EBSLN effectively may prevent voice damage after thyroid surgery.

Transoral Endoscopic Thyroidectomy by Vestibular Approach for Papillary Thyroid Carcinoma with Tumor Size ≥2 cm.

Background: The transoral endoscopic thyroidectomy by vestibular approach (TOETVA) has been developed for papillary thyroid carcinoma (PTC) treatment with satisfactory results. However, there were few malignant thyroid nodules ≥2 cm in previous studies of TOETVA. Therefore, we conducted this study to evaluate the results of treatment by TOETVA for PTC with tumor size ≥2 cm. Materials and Methods: The clinical characteristics and surgical outcomes of 10 PTC patients with tumor size ≥2 cm who underwent TOETVA in our center from June 2018 to August 2021 were, respectively, reviewed. Results: All 10 included PTC patients successfully underwent TOETVA and the mean tumor size was 2.5 ± 0.5 cm. The mean number lymph nodes dissected was 9.6 ± 2.9, and 3.1 ± 3.3 positive lymph nodes were discovered. Postoperatively, transient hypoparathyroidism was recorded in 2 patients (20%), transient recurrent laryngeal nerve injury was noted in 1 patient (10%), transient superior laryngeal nerve injury was noted in 1 patient (10%), and numb chin was identified in 1 patient (10%). The postoperative complications aforementioned recovered within 6 months. During a median follow-up of 23.8 ± 13.1 months, no other complications or tumor recurrence were found. Conclusions: TOETVA is feasible for PTC patients with tumor size ≥2 cm and satisfactory short-term surgical outcomes have achieved in this study. We suggested that experienced surgeons can gradually expand the indications for TOETVA.

Clinical application of transoral and submental thyroidectomy (TOaST): a series of 54 human cases

ObjectiveA new endoscopic thyroidectomy approach—transoral and submental endoscopic thyroidectomy (TOaST)—was applied in clinical practice and considered an improved approach for endoscopic thyroid surgery via the oral approach. This paper discusses the feasibility and effectiveness of this surgical method.MethodsA retrospective analysis was performed on the clinical data of 54 patients who had undergone TOaST in the thyroid disease center of the First Affiliated Hospital of Nanchang University between December 2020 and December 2021. The surgical data and techniques, complications, and cosmetic outcomes of these patients were studied.ResultsAmong the total 54 patients, 23 underwent unilateral subtotal thyroidectomy, 3 patients underwent bilateral subtotal thyroidectomy, 27 with unilateral thyroid cancer underwent affected thyroid + isthmus + central lymph node resection, and only 1 patient underwent total thyroidectomy. The mean operative time was 88.06 ± 12.03 min (range: 65–135 min), the mean intraoperative blood loss was 8.61 ± 4.60 ml (range: 5–20 ml), the mean postoperative drainage volume was 49.96 ± 9.88 ml (range: 30–60 ml), the mean drainage time was 36.61 ± 2.65 h (range: 32–50 h), and the mean length of hospital stay was 46.63 ± 3.28 h (range 45–70 h). One patient experienced transient recurrent laryngeal nerve injury, and another patient experienced transient parathyroid dysfunction; there was no superior laryngeal nerve injury and other complications, such as postoperative subcutaneous hematoma, hypercapnia, mental nerve injury, tracheoesophageal injury, infection, or lymphatic leakage.ConclusionTOaST cannot only achieve a good therapeutic effect but also avoid mental nerve injury, reduce the discomfort of the patient’s jaw, obtain a good cosmetic effect, and facilitate the operation of the operator. It is an endoscopic thyroidectomy technique with a certain clinical value.

A comparison between cisatracurium and rocuronium-induced neuromuscular block on laryngeal electromyography recovery after neostigmine reversal in a porcine model.

BackgroundInducing and reversing neuromuscular block is essential to a positive outcome of thyroid surgery, with intraoperative neuromonitoring (IONM) being used to decrease recurrent and superior laryngeal nerve injuries and improve vocal outcome. Neostigmine is a non-specific broad-spectrum and inexpensive reversal agent for neuromuscular blocking agents (NMBAs). The aim of this porcine study was to explore the effect of neostigmine on electromyography (EMG) signal recovery profile following the commonly used NMBAs, cisatracurium and rocuronium.MethodsTwelve piglets were allocated into two groups with six piglets in each group. When stable baseline EMG signals were obtained, a neuromuscular block was induced by intravenous cisatracurium 0.2 mg/kg (group C) or rocuronium 0.6 mg/kg (group R) for each piglet. We compared laryngeal EMG tracing with spontaneous recovery (control) and neostigmine (0.04 mg/kg) reversal for each group. The time course of real-time laryngeal EMG signals was observed for 30 min from NMBA injection. Effects of neostigmine on EMG signal were assessed at 50% EMG recovery and by the maximum neuromuscular block recovery degree from the baseline value.ResultsNeostigmine shortened the recovery time to 50% EMG amplitude in both group C (16.5 [2.5] vs. 29.0 [2.0] min, P<0.01) and group R (16.5[2.5] vs. 26.5 [1.5] min, P<0.05) compared to spontaneous recovery, respectively. Neostigmine reversal also enhanced the maximum degree of EMG amplitude recovery in both group C (83.6 [5.1] vs. 47.2 [6.1] %, P<0.01) and group R (85.6 [18.2]vs. 57.1 [6.3] %, P<0.05) compared to spontaneous recovery, respectively. The reversal effect of neostigmine did not differ significantly between cisatracurium and rocuronium.ConclusionsThis porcine model demonstrated that neostigmine provides an adequate and timely IONM signal suppressed by both cisatracurium and rocuronium. These results can potentially expand the options for precision neuromuscular block management during IONM to improve vocal outcomes in thyroid surgery patients.

Exploring the Clinical Characteristics of Superior Laryngeal Nerve Injury

To observe the cases of superior laryngeal nerve injury along with summarizing and analyzing its clinical characteristics. A total of 14 patients with unilateral superior laryngeal nerve injury (SLN) diagnosed by laryngeal electromyography (LEMG) in our department from 2018 to 2020 were collected as SLN injury group. A total of 14 healthy subjects with normal laryngeal electromyography were recruited as normal group matched by age and sex. The etiology and LEMG of the SLN injury group were analyzed, and the video stroboscopic manifestations of SLN injury group and normal group were compared to see the characteristic video stroboscopic manifestations of SLN injury. The most common causes of SLN injury were surgery and idiopathic etiology. Compared with normal group, the most frequent video stroboscopic manifestations of SLN injury group were vocal fold dyskinesia. Abnormal video stroboscopic manifestations occurred in normal group except larynx deviation, epiglottic petiole deviation, and dyskinesia. There was a significant difference between the two groups in various abnormal video stroboscopic manifestations (P < 0.05). Time limit widening was the most common manifestation of LEMG. Vocal fold dyskinesia was a prominent finding in SLN injury, laryngeal deviation and epiglottic petiole deviation were relative specific signs of SLN injury. Vocal fold bowing combined with shortening will contribute to the diagnosis of SLN injury. There were no specific diagnostic signs for SLN injury, clinicians need further LEMG for a firm diagnosis.

Factors associated with thyroidectomy complications in resource-limited settings: An observational study

Background: Even though thyroidectomy outcomes and their predictive factors are various and widely studied, the data from our country and other African countries where the disease burden is high are limited. The main aim of this study was to evaluate the incidence and factors associated with thyroidectomies complication in a resource limited setting where the procedures were performed by general surgeons/general surgery residents. MethodsThis is an observational study of one hundred ninety-nine patients undergoing elective thyroidectomy from September 1, 2020, to August 30, 2021. The primary outcomes are the incidence and types of complications observed during and after surgery. The secondary outcomes are identifying risk factors associated with complications. Bivariate and multivariate logistic regressions were used to identify risk factors. P-value < 0.05 was considered statistically significant. ResultThe incidence of complications after thyroid surgeries was 18.6%. The two commonest complications were an external branch of the superior laryngeal nerve (EBSLNI) injury and hypocalcemia. Thyroidectomy performed by residents and patients who underwent total thyroidectomy, the independent risk factor of the EBSLN injury [AOR = 8.015; 95%CI (1.402–45.807); P = 0.019 and postoperative hypocalcemia [AOR = 17.797; 95%CI (3.799–83.374); P < 0.001, resulted in an incidence of 7.54% and 5.53% respectively. ConclusionThe incidence of thyroidectomy complications is relatively similar to other studies. However, the provision of special training for residents on surgical techniques to prevent EBSLN injury and performing non-total thyroidectomies for benign thyroid diseases are recommended to reduce complications.

Stepwise approach to preserve the external branch of superior laryngeal nerve during thyroidectomy

BackgroundMost of the surgeons tend to avoid exposing and identification the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy. In this study, our aim is to assess sequential steps to ligate superior thyroid vessels safely away from the External branch of superior laryngeal nerve (EBSLN).MethodsThis prospective case series study was conducted on 60 patients going for either total or hemi thyroidectomy in a tertiary teaching hospital between January 2016 and June 2019. During thyroidectomy, firstly we skeletonized the upper pole of the thyroid gland by its capsular dissection followed by anterolateral down retraction of the superior pole. Then, entry and opening of the cricothyroid space and lastly clamping and ligating superior thyroid pedicle close to the upper pole away from EBSLN.ResultsThis study included 60 cases; 19 total thyroidectomy and 41 hemi thyroidectomy with 79 superior thyroid vessels ligation and EBSLN at risk. In all patients, no evidence of superior laryngeal nerve (SLN) palsy or bleeding was detected. Postoperative video laryngoendoscopy showed apparently normal mobility, length, level, and position of the vocal folds with symmetry of the larynx. The patients’ voice showed no changes from preoperative evaluation in all studied patients at 3 months postoperative evaluation. No patients complained of any changes in their voice or voice activities.ConclusionThe described stepwise approach for preservation of the EBSLN serves to completely remove the superior pole of the thyroid gland and ligate superior thyroid vascular pedicle without risk of SLN injury.

Clinical study of postoperative complications of thyroidectomy

Background: Thyroid surgery is one of the common surgeries performed by general surgeons, Head and neck surgeons, and endocrine surgeons today. The most common complications of thyroid surgery are bleeding, injury to recurrent laryngeal nerves, and parathyroid glands. Other complications include airway obstruction, superior laryngeal nerve injury, infections, and sometimes thyroid crisis. Patients with permanent recurrent laryngeal nerve palsy and hypocalcaemia have life-long problems with a need for continued medication, further surgeries, and rehabilitation. They have a compromised quality of life by an increase in individual's healthcare costs and requiring lifelong alternative therapies. Objectives: To evaluate the incidence of post thyroidectomy complications. It also intends to evaluate the preoperative and intra-operative factors that contribute to these complications. To assess the modalities to prevent such complications. Methods: A Prospective study was done from January 2018 to December 2019 on thyroid complications. A total of 78 patients were studied regarding the diagnosis, type of surgery, and the complications in them. The patients were followed up for 1 year. Results: The majority of patients (59%) were in the 3rd and 4th decade of life age. Female domination more than male. Multinodular goiter is the most common diagnosis. The most common complication was transient Hypocalcaemia (15.38%) and recurrent laryngeal nerve( 6.41%). Wound infections in 6.41%and seromas are 2.56%. The incidence of major bleed with respiratory obstruction and thyrotoxicosis is zero. No permanent debilitating complications of RL nerve injury or hypocalcaemia were noted. Conclusion: A thorough preoperative preparation, with adequate knowledge of Thyroid anatomy and steps of surgery is essential. A clean dissection, meticulous haemostasis and, identification and preservation of Recurrent Laryngeal and Parathyroids can relate to a low rate of complications. Extensive surgeries are associated with a higher rate of complications. Early recognition and prompt treatment of complications enable a better outcome for the patient.

Correlation Between Objective and Subjective High-Pitched Voice Impairment in Patients After Thyroid Surgery.

ObjectivesHigh-pitched voice impairment (HPVI) is not uncommon in patients without recurrent laryngeal nerve (RLN) or external branch of superior laryngeal nerve (EBSLN) injury after thyroidectomy. This study evaluated the correlation between subjective and objective HPVI in patients after thyroid surgery.MethodsThis study analyzed 775 patients without preoperative subjective HPVI and underwent neuromonitored thyroidectomy with normal RLN/EBSLN function. Multi-dimensional voice program, voice range profile and Index of voice and swallowing handicap of thyroidectomy (IVST) were performed during the preoperative(I) period and the immediate(II), short-term(III) and long-term(IV) postoperative periods. The severity of objective HPVI was categorized into four groups according to the decrease in maximum frequency (Fmax): <20%, 20-40%, 40-60%, and >60%. Subjective HPVI was evaluated according to the patient’s answers on the IVST.ResultsAs the severity of objective HPVI increased, patients were significantly more to receive bilateral surgery (p=0.002) and have subjective HPVI (p<0.001), and there was no correlation with IVST scores. Among 211(27.2%) patients with subjective HPVI, patients were significantly more to receive bilateral surgery (p=0.003) and central neck dissection(p<0.001). These patients had very similar trends for Fmax, pitch range, and mean fundamental frequency as patients with 20-40% Fmax decrease (p>0.05) and had higher Jitter, Shimmer, and IVST scores than patients in any of the objective HPVI groups; subjective HPVI lasted until period-IV.ConclusionThe factors that affect a patient’s subjective HPVI are complex, and voice stability (Jitter and Shimmer) is no less important than the Fmax level. When patients have subjective HPVI without a significant Fmax decrease after thyroid surgery, abnormal voice stability should be considered and managed. Fmax and IVST scores should be interpreted comprehensively, and surgeons and speech-language pathologists should work together to identify patients with HPVI early and arrange speech therapy for them. Regarding the process of fibrosis formation, anti-adhesive material application and postoperative intervention for HPVI require more future research.

Impact of Thyroid surgery on Voice: A prospective study.

Thyroidectomy is one of the most common neck surgery done worldwide. It is associated with debilitating post-operative voice changes even without recurrent laryngeal nerve (RLN) injury. Aims and Objectives: To study the impact of thyroidectomy on voice parameters in the absence of Recurrent Laryngeal Nerve and External Branch of Superior Laryngeal Nerve injury and comparison between the pre and post-operative changes in the subjective and objective voice parameters. Methodology: Patients fulfilling the inclusion criteria underwent thyroidectomy. The Subjective voice assessment was done using Voice Impairment Score (VIS) and objective parameters were analyzed using Multi-Dimensional Voice Program (MDVP) pre-operatively and post-operatively at 1week, 1month and 3months interval. Results: On MDVP analysis of patients, a fall in Mean F0 (Hz), Minimum F0 (Hz) and Maximum F0 (Hz) values was noted at 1week after surgery. But a trend toward the pre-operative values was observed at 3months post-operatively.

Visual identification and neuromonitoring vs. no sighting the external branch of the superior laryngeal nerve in thyroid surgery: a randomized clinical trial.

To evaluate the incidence of external branch of the superior laryngeal nerve (EBSLN) injuries after thyroid surgical procedures with or without the functional and visual identification of the EBSLN before ligation at the superior thyroid pole. Patients with papillary thyroid carcinoma (PTC) enrolled from a single tertiary referral academic medical center were assigned to functional and visual identification of EBSLN group (study group) or no identification of EBSLN group (controlled group). The main outcome measures were the incidence of EBSLN injury detected by the intraoperative neuromonitoring and Voice Handicap Index-10 (VHI-10) and Impairment Index-5 (VII-5) valuation questionnaires. Postoperative complications were recorded. A total of 140 (50.4%) patients were enrolled in study group and 138 (49.6%) in controlled group. In the study group, 110 (39.3%) EBSLNs were direct visual recognized and 170 (60.7%) nerves were visually identified with the help of neuromonitoring. Three patients in the study group and two patients in the controlled group were diagnosed with vocal cord paralysis. Six (4.4%) patients in the identification group and 37 (27.2%) patients in the no identification group presented no response from the stimulation of sternothyroid-laryngeal triangle. The VII-5 scores of the study group were significantly higher than those of the controlled group at one and three months postoperatively (P = 0.024 and P = 0.034). With significant lower scores of VII-5 and VHI-10, functional and visual identification of EBSLN might be necessary during thyroid surgery to protect the structural integrity and motor activity of the nerve.

Analysis of Risk Factors for Surgical Complications of Endoscopic Thyroidectomy via Total Areola Approach.

BackgroundIncreased surgical technology has led broad acceptance endoscopic thyroidectomy and its application in the treatment of thyroid diseases, including thyroid carcinoma. Although the incidence of complications and mortality of thyroid surgery has been significantly reduced, serious complications still occur from time to time. The purpose of this retrospective study is to identify the factors that influence the complications of endoscopic thyroidectomy.MethodsThis study was carried out between January 2012 and December 2019, where a total of 630 patients undergoing endoscopic thyroidectomy via the total areola approach were retrospectively evaluated to identify the key influencing factors of complications.ResultsThe study established that the common complications included recurrent laryngeal nerve injury (3.33%), superior laryngeal nerve injury (2.54%), hypocalcemia (8.57%), and the incidence of complications was acceptable. Both univariate and multivariate analysis showed that thyroid carcinoma (P = 0.041), operation time lasting more than 150 minutes (P = 0.034) and operation before 2017 (P = 0.001) were risk factors of recurrent laryngeal nerve injury. We established that operation after 2017 (P < 0.005) was the only protective factor of superior laryngeal nerve injury. Thyroid carcinoma (P=0.04), operation mode (P=0.001), and surgery before 2017 (P<0.001) are risk factors for parathyroid injury. Among the clinical groups, operation before 2017 was an independent risk factor for all complications.ConclusionFor thyroid specialists, after the early learning curve, with the continuous improvement of endoscopic operation technology, high-definition equipment and more sophisticated operation equipment can be used in clinical practice, which can prevent and reduce the occurrence of complications.

Superior Laryngeal Nerve Injury in Thyroidectomy Surgery

Introduction: The thyroid gland is one of the endocrine glands with the most frequent disorders or diseasescompared to other endocrine glands. Treatment of these disorders is generally performed by surgery orcalled a thyroidectomy. Thyroidectomy surgery can pose a risk of complications, both early complications,and late complications. Common complications are hemorrhage, hypoparathyroidism, recurrent laryngealnerve injury, and external branch of the superior laryngeal nerve.Purpose: To analyze the effect of the surgical method of superior thyroideal vasa ligation as distally aspossible on the prevention of injury to the external branch of the superior laryngeal nerve (EBSLN) inthyroidectomy.Methods: Clinical trial study with pre and post-test design in patients undergoing thyroidectomy surgery.Patients were examined using a questionnaire of the injury-related voice of EBSLN (SKC-EBSLN), whichtested the validity and reliability of the previous test and measured 1-octave sound ability before and afterthyroidectomy surgery using the superior thyroidectomy vasa ligation method as distally as possible to seeits effect on EBLSN function and tone ability function.Results: There were differences in the scores of the SKC-EBSLN questionnaire before and afterthyroidectomy surgery using the method of superior thyroideal vasa ligation as distally as possible (p&lt;0.05). Further analysis showed that clinical diagnosis, surgery, tumor size, and AP outcome did not havea statistically significant effect on the postoperative SKC-EBSLN score (p&gt; 0.05). In this study, the SKCEBSLN score had a significant effect on the 1-octave tone ability (p &lt;0.05).Conclusion: As many as 51.9% of patients had a normal voice condition with few complaints and wereable to sing 1-octave tone after surgery using the method of superior thyroidal vasa ligation as distally aspossible. The SKC-EBSLN questionnaire is a valid and reliable questionnaire to evaluate the results ofthyroidectomy surgery.

Recurrent and superior laryngeal nerve injury in thyroid surgery: literature review

Laryngeal nerve injury is considered one of the most common complications after thyroidectomy. It is associated with decreased quality of life because it will result in hoarseness of voice and aspiration. Identification of the risk factors and procedures to decrease the injury is crucial for handling laryngeal nerve injury. We searched the MEDLINE database using PubMed. Two independent reviewers reviewed the resulting papers and reviewed them based on our inclusion criteria. Based on the review results, the incidence of recurrent laryngeal nerve injury is higher than the external branch of the superior laryngeal nerve, but it is mainly due to under-reporting of the external branch of superior laryngeal nerve injury. Cancer surgery, surgeon experience, workload, re-operative procedures, and extent of surgery increased the incidence of the laryngeal nerve injury. Handling of these risk factors combined with visual dissection and inspection and/or intraoperative nerve monitoring decreased the incidence of the nerve injury. In conclusion, laryngeal nerve injury is a common post thyroidectomy complication. Anatomical dissection and visual inspection combined with intraoperative nerve monitoring is the most suitable option in high-risk thyroid surgeries.

Protection of nerve function during transoral endoscopic thyroidectomy by vestibular approach

Objective: To explore the method of functional protection in transoral endoscopic thyroidectomy by vestibular approach. Methods: Retrospective analysis was performed on the case data of 66 patients who underwent transoral endoscopic thyroidectomy by vestibular approach in the Department of Otorhinolaryngology Head and Neck Surgery of Beijing Tongren Hospital from February 2018 to February 2020. There were 11 males and 55 females aged 22-64 years, including 19 patients with benign diseases and 47 patients with malignant diseases. Important neurological functions were protected by a combination of anatomical exposure and intraoperative nerve monitoring. The clinical data and the effect of neurofunctional protection were summarized. SPSS 25.0 software was used for statistical analysis. Results: All operations were successfully completed with none transferred to open surgery. Three weeks after surgery, the numbness and tingling symptoms in the lower jaw and lower lip were basically relieved. There was no permanent mental nerve palsy, no permanent recurrent laryngeal nerve palsy but 2 cases with temporary recurrent laryngeal nerve palsy, no external branch injury of superior laryngeal nerve. There were 3 cases of temporary parathyroid gland dysfunction, 1 case of neck infection, 2 cases of subcutaneous effusion, 1 case of neck skin injury, and 2 cases of postoperative eye conjunctivitis. Conclusion: In transoral endoscopic thyroidectomy by vestibular approach, anatomical exposure can decrease mental nerve injury, and anatomical exposure combined with intraoperative nerve monitoring can protect the functions of the external branches of the superior laryngeal nerve and the recurrent laryngeal nerve.

Assessment of nerve stimulation during thyroidectomy for identification of the external branch of superior laryngeal nerve

Background The external branch of the superior laryngeal nerve (EBSLN) injury is an important and not uncommon, though frequently overlooked, complication of thyroid surgery. The rate of EBSLN injury has been reported to vary from 0 to 58%, depending on different postoperative assessment methods. Injury to the EBSLN during thyroid operation can paralyze ipsilateral cricothyroid muscle, and the clinical symptoms mainly include vocal fatigue and diminished vocal frequency range, especially with respect to raising pitch, which may result in decreased quality of life, particularly for voice professionals. Patients and methods This prospective study included 22 patients with goiter. They were divided into two groups: group 1 (G1) included all cases in whom nerve stimulator was used and group 2 (G2) included all cases in whom trial of visual identification of the EBSLN was done. Results It was found that patients with short obese neck, large gland size, large gland weight, and retrosternal extension showed difficulty in EBSLN identification and had high risk of nerve injury (P Conclusion It was concluded that routine use of nerve stimulator in surgical interventions on the thyroid gland will be beneficial for more secure identification and prevention of EBSLN injury and preservation of voice quality postoperatively.

Ultrasonic osteotome versus high-speed burr in cervical anterior vertebral subtotal resection: A retrospective study of 81 cases

AimThis study aimed to investigate the safety and effectiveness of ultrasonic osteotome in cervical anterior vertebral subtotal resection. MethodsRetrospective clinical data were collated for 81 patients with cervical spondylotic myelopathy who required cervical anterior vertebral subtotal resection. ResultsGroup A (n=40) was treated with an ultrasonic osteotome and group B (n=41) with a high-speed burr. Vertebrectomy time, intraoperative blood loss, surgical complications, Japanese Orthopedic Association (JOA) scores and JOA score improvement were compared. Group A showed significantly shorter vertebrectomy time and significantly less intraoperative blood loss (P<0.05). In group A, dysphagia occurred in one patient, and superior laryngeal nerve injury in one. Urinary tract infection occurred in one patient in group B. JOA score in both groups significantly increased 3 days after surgery (P<0.05), and at last follow-up compared with 3 days after surgery (P<0.05). ConclusionUltrasonic osteotome was a safe and effective tool for subtotal anterior cervical vertebral resection.