Risk of recurrent laryngeal nerve palsy in patients undergoing thyroidectomy with and without intraoperative nerve monitoring

Effects on Voice Quality of Thyroidectomy: A Qualitative and Quantitative Study Using Voice Maps

OBJECTIVES

This study aims to explore the effects of thyroidectomy-a surgical intervention involving the removal of the thyroid gland-on voice quality, as represented by acoustic and electroglottographic measures. Given the thyroid gland's proximity to the inferior and superior laryngeal nerves, thyroidectomy carries a potential risk of affecting vocal function. While earlier studies have documented effects on the voice range, few studies have looked at voice quality after thyroidectomy. Since voice quality effects could manifest in many ways, that a priori are unknown, we wish to apply an exploratory approach that collects many data points from several metrics.

METHODS

A voice-mapping analysis paradigm was applied retrospectively on a corpus of spoken and sung sentences produced by patients who had thyroid surgery. Voice quality changes were assessed objectively for 57 patients prior to surgery and 2months after surgery, by making comparative voice maps, pre- and post-intervention, of six acoustic and electroglottographic (EGG) metrics.

RESULTS

After thyroidectomy, statistically significant changes consistent with a worsening of voice quality were observed in most metrics. For all individual metrics, however, the effect sizes were too small to be clinically relevant. Statistical clustering of the metrics helped to clarify the nature of these changes. While partial thyroidectomy demonstrated greater uniformity than did total thyroidectomy, the type of perioperative damage had no discernible impact on voice quality.

CONCLUSIONS

Changes in voice quality after thyroidectomy were related mostly to increased phonatory instability in both the acoustic and EGG metrics. Clustered voice metrics exhibited a higher correlation to voice complaints than did individual voice metrics.

Real-time imaging of ipsilateral parathyroid glands by retrograde injection of methylene blue into the superior thyroid artery: a new intraoperative parathyroid protection method

BACKGROUND

Postoperative hypoparathyroidism caused by parathyroid injury is a problem faced by thyroid surgeons. The current technologies for parathyroid imaging all have some defects.

METHODS

Patients with differentiated thyroid carcinoma (DTC) who underwent unilateral thyroidectomy plus ipsilateral central lymph node dissection were recruited. We dissected the main trunk of the superior thyroid artery entering the thyroid gland and placed the venous indwelling tube into the artery. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated.

RESULTS

A total of 132 patients enrolled in this single-arm clinical trial, 105 of them completed retrograde catheterization via the superior artery. The sensitivity was 69.23 and 83.33% respectively. The specificity was 72.91 and 64.89%. The accuracy was 72.91 and 64.89%. The PPV was 85.71 and 81.08%. The NPV was 22.58 and 45.45%. There were no patients with allergic reactions to the methylene blue, or methylene blue toxicity.

CONCLUSIONS

Retrograde injection of methylene blue via the superior thyroid artery is an effective and safe method to visualize parathyroid glands. This method can accurately locate the target organ by ultraselecting the blood vessel and injecting the contrast agent while avoiding background contamination and reducing the amount of contrast agent.

TRIAL REGISTRATION

Clinical trial registration numbers and date of registration: ChiCTR2300077263、02/11/2023.

Utilizing Surgeon-Performed Intraoperative Translaryngeal Ultrasound for Verifying Vocal Fold Function: A Troubleshooting Approach for Intraoperative Neuromonitoring in Neck Surgery

INTRODUCTION

We investigated transcutaneous laryngeal ultrasonography (TLUS) for assessing vocal fold (VF) mobility during thyroid and parathyroid surgeries, emphasizing its precision and utility in signal loss scenarios.

METHODS

Between October 2020 and January 2023, we performed TLUS, Doppler sonography, laryngeal twitch response (LTR) palpation, and electromyography (EMG) to monitor recurrent laryngeal nerve function during neck surgeries. Postoperatively, the VF activity was verified using fiberoptic video laryngoscopy (FL). Concordance with FL was categorized based on VF activity.

RESULTS

Of the 443 VF evaluations, no instances of permanent bilateral paralysis were noted. Temporary unilateral palsy was found in 3.38% and permanent in 0.45%. TLUS displayed 97.8% agreement with EMG and was diagnostically superior (99.7% vs 98.2%) and more affordable ($68 vs $300) compared to analogous operative durations.

CONCLUSION

TLUS rivals EMG in terms of intraoperative neuromonitoring accuracy and outperforms LTR. Being cost-effective, TLUS can effectively address signal loss situations, thereby averting additional surgeries.

Hemithyroidectomy, does the indication influence the outcome?

PURPOSE

Hemithyroidectomies are mainly performed for two indications, either therapeutically to relieve compression symptoms or diagnostically for suspicious nodule(s). In case of the latter, one could consider the approach to be rather extensive since the majority of patients have no symptoms and will have benign disease. The aim of this study is to investigate the complication rates of diagnostic hemithyroidectomy and to compare it with the complication rates of compressive symptoms hemithyroidectomy.

METHODS

Data from patients who had undergone hemithyroidectomy either for compression symptoms or for excluding malignancy were extracted from a well-established Scandinavian quality register (SQRTPA). The following complications were analyzed: bleedings, wound infections, and paresis of the recurrent laryngeal nerve (RLN). Risk factors for these complications were examined by univariable and multivariable logistic regression.

RESULTS

A total of 9677 patients were included, 3871 (40%) underwent surgery to exclude malignancy and 5806 (60%) due to compression symptoms. In the multivariable analysis, the totally excised thyroid weight was an independent risk factor for bleeding. Permanent (6-12 months after the operation) RLN paresis were less common in the excluding malignancy group (p = 0.03).

CONCLUSION

A range of factors interfere and contribute to bleeding, wound infections, and RLN paresis after hemithyroidectomy. In this observational study based on a Scandinavian quality register, the indication "excluding malignancy" for hemithyroidectomy is associated with less permanent RLN paresis than the indication "compression symptoms." Thus, patients undergoing diagnostic hemithyroidectomy can be reassured that this procedure is a safe surgical procedure and does not entail an unjustified risk.

Short term Outcomes of Routine Exposure Versus non Exposure of the Recurrent Laryngeal Nerve During Thyroidectomy for Benign Thyroid Diseases

Aims

To evaluate the outcomes of the exposure versus non-exposure of the RLN during thyroidectomy for benign thyroid diseases.

Materials and methods

A prospective study for patients who underwent thyroidectomy for benign diseases. They were classified into two groups, group 1 (the exposed group) and group 2 (the non-exposed group) of the RLN. History, examination, laboratory and radiological investigations as well as intra and post-operative details were recorded.

Results

97 patients were included in the study, group 1 (63 patients) while group 2 (34 patients). The median age of both groups was 40 (for group 1) and 42 (for group 2) respectively. There was no significant difference regarding the gender of the patients (P = 0.089) and the type of surgery (P = 0.234). The duration of surgery as well as the amount of intraoperative blood loss were equal with no significant difference (P = 0.791) (P = 0.225). Hematoma was detected in three patients in the exposed group while RLN injury was detected in 5 patients in total (2 in group 1 and 3 in group 2) without any significant difference. There was significant hypocalcemia in favor of the non-exposed group (P = 0.001). Regarding the postoperative hospital stay, there was no significant difference between both groups (P = 0.720).

Conclusions

Exposure versus non-exposure of the RLN is still considered a matter of debate but precautions during dissection are a very useful maneuver. Meanwhile, it is better to expose the nerve with meticulous dissection and preservation of the parathyroid gland vascularity.

The TOFr of 0.75 to 0.85 is the optimal timing for IONM during thyroid surgery: a prospective observational cohort study

BACKGROUD

Recurrent laryngeal nerve (RLN) injury is one of the serious complications of thyroid tumour surgery, surgical treatment of thyroid cancer requires careful consideration of the RLN and its impact on glottis function. There has been no unified standard for precise neuromuscular block monitoring to guide the monitoring of RLN in thyroid surgery. This study aimed to investigate the correlation between Train-of-four stabilization ratio (TOFr) and neural signal values of intraoperative neurophysiological monitoring (INOM) during thyroid operation, and further to determine the optimal timing for INOM during thyroid operation.

METHODS

Patients scheduled for thyroid tumour resection with INOM and RLN monitoring from April 2018 to July 2018 in our center were recruited. Electromyography (EMG) signals and corresponding TOFr were collected. All nerve stimulation data were included in group VR. Vagus nerve stimulation data were included in Subgroup V. RLN stimulation data were included in Subgroup R. The timing of recording was as follows: Vagus nerve EMG amplitude after opening the lateral space between the thyroid and carotid sheath and before the initiation of thyroid dissection, RLN EMG amplitude at first recognition, RLN EMG amplitude after complete thyroid dissection (Repeat three times), and Vagus nerve EMG amplitude after resection of the thyroid (Repeat three times). Correlation analysis of continuous variables was described by a scatter diagram. Pearson correlation analysis or Spearman correlation analysis was used for the two groups of variables.

RESULTS

Finally, 134 vagus nerve signals and 143 RLN signals were analysed after matching with TOFr. The EMG amplitude in the VR group and subgroups after nerve stimulation was positively correlated with TOFr (p < 0.05). In the VR, V and R group, the incidence of EMG ≥ 500 µV in the 0.75 < TOFr ≤ 0.85 interval was significantly higher than the 0 < TOFr ≤ 0.75 interval (P = 0.002, P = 0.013 and P = 0.029), and has no statistical difference compared to 0.85 < TOFr ≤ 0.95 interval (P > 0.05).

CONCLUSIONS

The EMG signals of the RLN and vagus nerve stimulation during thyroid surgery were positively correlated with TOFr. TOFr > 0.75 could reflect more than 50% of the effective nerve electrophysiological signals, 0.75 < TOFr ≤ 0.85 interval was the optimal timing for IONM during thyroid surgery.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR1800015797) Registered on 20/04/2018. https://www.chictr.org.cn .

Operative Management of Thyroid Disease in Older Adults

As the population ages, both domestically and globally, clinicians will increasingly find themselves navigating treatment decisions for thyroid disease in older adults. When considering surgical treatment, individualizing risk assessment is particularly important, as older patients can present with very different health profiles. While fit, independent individuals may benefit from thyroidectomy with minimal risk, those with multiple comorbidities and poor functional status are at higher risk of perioperative complications, which can have adverse health effects and detract from long-term quality of life. In order to optimize surgical outcomes for older adults, strategies for accurate risk assessment and mitigation are being explored. Surgical decision-making also should consider the characteristics of the thyroid disease being treated, given many benign thyroid disorders and some well-differentiated thyroid cancers can be appropriately managed nonoperatively without compromising longevity. Shared decision-making becomes increasingly important to respect the health priorities and optimize outcomes for older adults with thyroid disease. This review summarizes the current knowledge of thyroid surgery in older adults to help inform decision-making among patients and their physicians.

A novel computer based risk prediction model for vocal cord palsy before thyroidectomy

BACKGROUND

Thyroidectomy may be performed for clinical indications that include malignancy, benign nodules or cysts suspicious findings on fine needle aspiration (FNA) biopsy, dyspnea from airway compression or dysphagia from cervical esophageal compression, etc. The incidences of vocal cord palsy (VCP) caused by thyroid surgery were reported to range from 3.4% to 7.2% and 0.2% to 0.9% for temporary and permanent vocal fold palsy respectively which is a serious complication of thyroidectomy that is worrisome for patients.

OBJECTIVE

Therefore, it is aimed to determine the patients who have the risk of developing vocal cord palsy before thyroidectomy by using machine learning methods in the study. In this way, the possibility of developing palsy can be reduced by applying appropriate surgical techniques to individuals in the high-risk group.

METHOD

For this aim, 1039 patients with thyroidectomy, between the years 2015 and 2018, have been used from Karadeniz Technical University Medical Faculty Farabi Hospital at the department of general surgery. The clinical risk prediction model was developed using the proposed sampling and random forest classification method on the dataset.

CONCLUSION

As a result, a novel quite a satisfactory prediction model with 100% accuracy was developed for VCP before thyroidectomy. Using this clinical risk prediction model, physicians can be helped to identify patients at high risk of developing post-operative palsy before the operation.

[Predictive value of strobovideolaryngoscopy, acoustic and aerodynamic measures in the prognosis of temporally unilateral vocal fold paralysis after thyroidectomy]

Objective:To investigate the strobovideolaryngoscopy, acoustic and aerodynamic characteristics of transient unilateral vocal ford paralysis（UVFP） after thyroidectomy. Methods:A retrospective analysis was made of 11 patients with temporary UVFP after thyroidectomy who were treated in Department of Otolaryngology and Head and Neck Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University from January 2013 to March 2021; 8 patients with permanent UVFP after thyroidectomy during the same period were included as a control group. The differences in baseline strobovideolaryngoscopy, acoustic and aerodynamic measures were compared between the two groups. Results:The tones of patients with temporary UVFP after thyroidectomy were all normal, and the proportions of abnormal vocal fords（vocal ford bowing, atrophy, and shortening）, ventricular adduction and glottic insufficiency were significantly lower than those of permanent UVFP patients; arytenoid cartilage stability and height mismatch of vocal ford tended to be better than permanent UVFP. The maximal phonation time（MPT） in patients with temporary UVFP was （8.5±4.1） s, which was significantly longer than （3.9±2.1） s in patients with permanent UVFP; fundamental frequency, mean airflow（MeAF） and mean subglottic pressure（SGP） were better in temporary UVFP than those in patients with permanent UVFP, but the difference did not reach statistical significance. Conclusion:None and mild glottic insufficiency, normal tone, ventricular adduction, and vocal ford appearances without vocal fold bowing, atrophy, and shortening, can be served as the predictors for the early recovery of vocal ford movement in temporary UVFP after thyroidectomy. The MPT less than 4 s, and MeAF, and SGP remarkably increased is the predictor of poor prognosis for vocal ford recovery.

Microwave ablation vs. surgery for papillary thyroid carcinoma with minimal sonographic extrathyroid extension: a multicentre prospective study

OBJECTIVES

Minimal extrathyroid extension (mETE) was removed from the TNM staging system. This study was designed prospectively to compare the safety and efficacy of microwave ablation (MWA) versus surgery for treating T1N0M0 papillary thyroid carcinomas (PTC) with sonographically detected mETE.

METHODS

From December 2019 to April 2021, 198 patients with T1N0M0 mETE-PTCs evaluated by preoperative ultrasound from 10 hospitals were included. Ninety-two patients elected MWA, and 106 patients elected surgery for treatment. MWA was performed using extensive ablation with hydrodissection. Surgery consisted of lobectomy with ipsilateral central lymph node dissection (CLD), lobe and isthmus excision with ipsilateral CLD and total thyroidectomy with ipsilateral CLD. The rates of technical success, cost, oncologic outcomes, complications and quality of life of the two groups were assessed.

RESULTS

The follow-up times for the MWA and surgery groups were 12.7 ± 4.1 and 12.6 ± 5.0 months, respectively. The technical success rate was 100% for both groups. Oncological outcomes of the two groups were similar during the follow-up (all p > 0.05). The MWA group had a shorter operation time, less blood loss and lower costs (all p < 0.001). Three complications (3.3%) were reported in the MWA group and 4 (3.8%) in the surgery group (p = 0.846). The surgery group had higher scores for scar problems and anxiety (p < 0.001 and p = 0.003, respectively).

CONCLUSIONS

Microwave ablation was comparable in the short term to surgery in terms of treatment safety and efficacy in selected patients with T1N0M0 mETE-PTC detected by ultrasound.

KEY POINTS

• Microwave ablation is comparable to surgery in the safety and short-term efficacy for PTCs with sonographically detected mETE. • Thermal ablation is technically feasible for mETE-PTC treatment. • Patients with mETE-PTC have similar quality of life in the two groups, except for worse scar problems and anxiety in the surgery group.

Effects of Intraoperative Neural Tunnel in Protecting Recurrent Laryngeal Nerve: Experiences in Open, Trans Breast, and Transoral Endoscopic Thyroidectomy

Background

Energy-based devices (EBDs) increase the risks of thermal nerve injuries. This study aimed to introduce a surgical strategy of intraoperative neural tunnel protecting (INTP) for evaluating the effect in reducing the incidence of recurrent laryngeal nerve (RLN) damage in open, trans breast, and transoral endoscopic thyroidectomy.

Methods

INTP strategy was introduced: a tunnel was established and protected by endoscopic gauze along the direction of the nerve. A total of 165, 94, and 200 patients with papillary thyroid carcinoma (PTC) were to use INTP in respectively open, trans breast, and transoral endoscopic thyroidectomy as the INTP group. Additionally, 150, 95, and 225 patients who received the same methods without INTP were enrolled in the control group. Ipsilateral thyroidectomy or total thyroidectomy, and central compartment dissection were performed on the enrolled patients.

Results

Clinicopathologic characteristics, surgical outcomes, and surgical complications were similar between the INTP group and the control group in open, trans breast, and transoral endoscopic thyroidectomy. The incidences of electromyography (EMG) changes in the INTP group were lower as compared to the control group in trans breast endoscopic thyroidectomy (p < 0.05). The incidence of postoperative hoarse in the INTP group was lower as compared to the control group in open and transoral endoscopic thyroidectomy (p < 0.05). Postoperative calcium levels (p < 0.01) were significantly higher, and the white blood cells (p < 0.05) and C-reactive protein levels (p < 0.01) were significantly decreased in the INTP group compared with the control group in transoral endoscopic thyroidectomy.

Conclusions

This was the first instance of the INTP strategy being introduced and was found to be an effective method for protecting the RLN in open, trans breast, and transoral endoscopic thyroidectomy. Additionally, INTP helped protect other important tissues such as the parathyroid glands in transoral endoscopic thyroidectomy as well as in reducing postoperative inflammatory responses.

Translaryngeal ultrasound in thyroid surgery: state of the art review

BACKGROUND

Clinical voice assessment prior to thyroid and parathyroid surgery is essential, but the paradigm of indirect laryngoscopy (IDL), when indicated, has been challenged by the risk of aerosolised SARS-Cov-2 during endoscopy of the aerodigestive tract. Translaryngeal ultrasound (TLUS) to assess the vocal cords has been proposed as a safe, non-invasive and sensitive alternative. The aim of this review was to verify TLUS as a viable tool for perioperative laryngeal assessment.

METHOD

A literature review was performed using Medline, Embase, Cochrane Database of Systematic Reviews, Cochrane Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials and Scopus with the following search strategy: (vocal cord OR vocal fold OR glottic OR glottis OR vocal ligaments OR rima glottidis) AND (ultras* OR sonograph* OR echography OR echotomography).

RESULTS

Fifteen studies were included in this review. All studies compared TLUS to IDL in visualizing the vocal cords in adults. Ten studies compared pre-operative TLUS to IDL where 50.6-100% of vocal cords were successfully visualized. Nine studies compared post-operative TLUS to IDL and reported visualization between 39.6% and 100%. Pre- and post-operative negative predictive values ranged from 60% to 100%.

CONCLUSION

Whilst promising, successful visualization of the cords is limited by inter-user variability, older age and male gender. Thus, we see the role of TLUS as an alternative to IDL in the post-operative setting in the young patient following uncomplicated surgery with a normal voice on clinical examination, to confirm recurrent laryngeal nerve integrity while minimizing the risk of aerosolization.

Impact of body mass index on short-term outcomes after differentiated thyroid cancer surgery: a nationwide inpatient database study in Japan

INTRODUCTION

Recent studies have shown worse post-operative outcomes following several surgeries in underweight or obese patients. However, the association between body mass index (BMI) and short-term outcomes following thyroid cancer surgery remains unclear because of the small number of patients, deficits in background data known as risk factors (e.g. cancer stage, operative procedure, intraoperative device use and hospital volume) and categorisation of BMI.

METHODS

We identified patients who underwent thyroidectomy for differentiated thyroid cancer from July 2010 to March 2017 using a Japanese nationwide inpatient database. We used restricted cubic spline (RCS) analyses to investigate potential non-linear associations between BMI (without categorisation) and outcomes: post-operative complications (local and general), duration of anaesthesia, post-operative length of hospital stay and hospitalisation costs. The analyses were adjusted for demographic and clinical backgrounds including the above-stated factors. We also performed multivariable regression analyses for the outcomes with categorisation of BMI.

RESULTS

Among 59,671 eligible patients, the median BMI was 22.9 kg/m2 (interquartile range (IQR), 20.7-25.6 kg/m2). In total, 3860 patients (6.5%) had local complications and 787 patients (1.3%) had general complications. Although there were no significant associations with local complications, such as bleeding, recurrent laryngeal nerve paralysis and surgical site infection, the occurrence of general complications was significantly associated with higher BMI. BMI showed a linear association with the duration of anaesthesia and U-shaped associations with post-operative length of stay and hospitalisation costs. The lowest points of the U-shaped curves occurred at a BMI of approximately 24 kg/m2. The multivariate regression analyses showed consistent results with the RCS analyses.

DISCUSSION/CONCLUSION

Whereas RCS analyses revealed no significant associations between BMI and post-operative local complications, obesity was significantly associated with the occurrence of general complications. The linear association between BMI and duration of anaesthesia corresponds to previous studies. Although post-operative length of stay and total hospitalisation costs demonstrated U-shaped associations, the slight differences would not be clinically important. Even if surgeons must pay attention to general complications in obese patients undergoing thyroid cancer surgery as well as other surgeries, underweight and overweight patients can undergo thyroidectomy as safely as patients with normal BMI.

Continuous Intraoperative Recurrent Laryngeal Nerve Monitoring: Techniques, Applications, and Controversies

Purpose of Review

Purpose of the present review is to illustrate the current state of the art concerning continuous intraoperative recurrent laryngeal nerve monitoring (cIONM) for thyroid surgery.

Recent Findings

cIONM potentially leads to an improved postoperative vocal cord palsy rate, compared to the intermittent technique. There are currently two main approaches for cIONM: either conventional cIONM based on vagal nerve stimulation or experimental methods, which do not require the positioning of a vagal nerve electrode. One of these methods is the recently described technique “LAR-cIONM,” which utilizes the laryngeal adductor reflex.

Summary

cIONM represents an advancement of intermittent nerve monitoring, which allows for an immediate reaction to signal changes. Threshold values and guidelines to prevent recurrent laryngeal nerve palsy were validated for the direct stimulation of the vagal nerve and require verification for alterative cIONM methods, including LAR-cIONM.

Complications after medullary thyroid carcinoma surgery: multicentre study of the SQRTPA and EUROCRINE® databases

BACKGROUND

Surgery is the curative therapy for patients with medullary thyroid carcinoma (MTC). In determining the extent of surgery, the risk of complications should be considered. The aim of this study was to assess procedure-specific outcomes and risk factors for complications after surgery for MTC.

METHODS

Patients who underwent thyroid surgery for MTC were identified in two European prospective quality databases. Hypoparathyroidism was defined by treatment with calcium/active vitamin D. Recurrent laryngeal nerve (RLN) palsy was diagnosed on laryngoscopy. Complications were considered at least transient if present at last follow-up. Risk factors for at-least transient hypoparathyroidism and RLN palsy were identified by logistic regression analysis.

RESULTS

A total of 650 patients underwent surgery in 69 centres at a median age of 56 years. Hypoparathyroidism, RLN palsy and bleeding requiring reoperation occurred in 170 (26·2 per cent), 62 (13·7 per cent) and 17 (2·6 per cent) respectively. Factors associated with hypoparathyroidism were central lymph node dissection (CLND) (odds ratio (OR) 2·20, 95 per cent c.i. 1·04 to 4·67), CLND plus unilateral lateral lymph node dissection (LLND) (OR 2·78, 1·20 to 6·43), CLND plus bilateral LLND (OR 2·83, 1·13 to 7·05) and four or more parathyroid glands observed (OR 4·18, 1·46 to 12·00). RLN palsy was associated with CLND plus LLND (OR 4·04, 1·12 to 14·58) and T4 tumours (OR 12·16, 4·46 to 33·18). After compartment-oriented lymph node dissection, N0 status was achieved in 248 of 537 patients (46·2 per cent).

CONCLUSION

Complications after surgery for MTC are procedure-specific and may relate to the unavoidable consequences of radical dissection needed in some patients.

Intraoperative nerve monitoring in thyroid surgery: analysis of United Kingdom registry of endocrine and thyroid surgery database

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.

Intraoperative neuromonitoring (IONM) in thyroidectomy for carcinoma in an high volume academic Hospital

BACKGROUND

The diagnosis of thyroid carcinoma has changed in last decades, as the surgical technique during thyroidectomy (endoscopic surgery, robotic surgery, new energy device, intraoperative neuromonitoring).

METHODS

We analyzed patients undergone to thyroidectomy or lobectomy for thyroid carcinoma from January 2010 to December 2019 at the General Surgery Unit of the Hospital - University of Parma. We divided patients into two groups, based on the use or not of IONM.

RESULTS

We analyzed data about 638 patients, 486 (76.2%) female and 152 (23.8%) male, with a mean age of 51.8 years. Totally, 574 patients underwent total thyroidectomy and lymphadenectomy was performed in 39 patients. The lobectomy rate was higher in interventions with neuromonitoring (13.93%) than in those without IONM (3.06%). Considering the incidence of postoperative complications and the presence of infiltration of perithyroid tissues or thyroiditis or lymph node metastasis at the histological report, a statistically significant percentage of dysphonia and paraesthesia was recorded only in patients with infiltration of perithyroid tissues (p <0.0001). There was no significant difference in postoperative blood calcium values. The use of intraoperative neuromonitoring has not significantly changed the incidence of postoperative complication.

CONCLUSIONS

Our study did not show a protective impact of the use of intraoperative neuromonitoring during thyroidectomy on the incidence of postoperative complications but confirmed that it increases the surgeon's feel safety during surgery and facilitates the identification of any undetected nerve lesion with visually intact nerve, inducing the interruption of the thyroidectomy after lobectomy alone, reducing the risk of bilateral recurrent paralysis.

The PanSurg-PREDICT Study: Endocrine Surgery During the COVID-19 Pandemic

Background

In the midst of the COVID-19 pandemic, patients have continued to present with endocrine (surgical) pathology in an environment depleted of resources. This study investigated how the pandemic affected endocrine surgery practice.

Methods

PanSurg-PREDICT is an international, multicentre, prospective, observational cohort study of emergency and elective surgical patients in secondary/tertiary care during the pandemic. PREDICT-Endocrine collected endocrine-specific data alongside demographics, COVID-19 and outcome data from 11–3-2020 to 13–9-2020.

Results

A total of 380 endocrine surgery patients (19 centres, 12 countries) were analysed (224 thyroidectomies, 116 parathyroidectomies, 40 adrenalectomies). Ninety-seven percent were elective, and 63% needed surgery within 4 weeks. Eight percent were initially deferred but had surgery during the pandemic; less than 1% percent was deferred for more than 6 months. Decision-making was affected by capacity, COVID-19 status or the pandemic in 17%, 5% and 7% of cases. Indication was cancer/worrying lesion in 61% of thyroidectomies and 73% of adrenalectomies and calcium 2.80 mmol/l or greater in 50% of parathyroidectomies. COVID-19 status was unknown at presentation in 92% and remained unknown before surgery in 30%. Two-thirds were asked to self-isolate before surgery. There was one COVID-19-related ICU admission and no mortalities. Consultant-delivered care occurred in a majority (anaesthetist 96%, primary surgeon 76%). Post-operative vocal cord check was reported in only 14% of neck endocrine operations. Both of these observations are likely to reflect modification of practice due to the pandemic.

Conclusion

The COVID-19 pandemic has affected endocrine surgical decision-making, case mix and personnel delivering care. Significant variation was seen in COVID-19 risk mitigation measures. COVID-19-related complications were uncommon. This analysis demonstrates the safety of endocrine surgery during this pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-021-06099-z.

The Anatomical and Clinical Significance of the Superior Laryngeal Nerve

OBJECTIVE

This study summarizes the anatomical features of the superior laryngeal nerve in Chinese to enable the rapid location of the superior laryngeal nerve during an operation.

STUDY DESIGN

Retrospective analysis of anatomical data.

SETTING

Hangzhou First People's Hospital Affiliated to Nanjing Medical University.

METHODS

A total of 71 embalmed human cadavers (132 heminecks) were examined over 3 months. The length and diameter of the internal and external branches of the superior laryngeal nerve and their relationships with different landmarks were recorded.

RESULTS

The total length of the internal branch of the superior laryngeal nerve was 23.4 ± 6.9 mm. The length of the external branch of the superior laryngeal nerve was 47.7 ± 11.0 mm. Considering the midpoint of the lower edge of the thyroid cartilage as the starting point and using that edge as a horizontal line, when the entry point is above that line, the external branch of the superior laryngeal nerve can be found within 41.1 mm and at an angle of 57.2°. When the entry point is below the lower edge of the thyroid cartilage, the external branch of the superior laryngeal nerve can be found within 34.0 mm and at an angle of 36.5°.

CONCLUSION

The superior laryngeal nerve in Chinese people has distinct anatomical characteristics. This article provides a new method of quickly locating the external branch of the superior laryngeal nerve during the operation, which can reduce the probability of damaging the external branch of the superior laryngeal nerve.

New Developments in Anterior Laryngeal Recording Technique During Neuromonitored Thyroid and Parathyroid Surgery

A recurrent laryngeal nerve (RLN) injury resulting in vocal fold paralysis and dysphonia remains a major source of morbidity after thyroid and parathyroid surgeries. Intraoperative neural monitoring (IONM) is increasingly accepted as an adjunct to the standard practice of visual RLN identification. Endotracheal tube (ET) surface recording electrode systems are now widely used for IONM; however, the major limitation of the clinical use of ET-based surface electrodes is the need to maintain constant contact between the electrodes and vocal folds during surgery to obtain a high-quality recording. An ET that is malpositioned during intubation or displaced during surgical manipulation can cause a false decrease or loss of electromyography (EMG) signal. Since it may be difficult to distinguish from an EMG change caused by a true RLN injury, a false loss or decrease in EMG signal may contribute to inappropriate surgical decision making. Therefore, researchers have investigated alternative electrode systems that circumvent common causes of poor accuracy in ET-based neuromonitoring. Recent experimental and clinical studies have confirmed the hypothesis that needle or adhesive surface recording electrodes attached to the thyroid cartilage (transcartilage and percutaneous recording) or attached to the overlying neck skin (transcutaneous recording) can provide functionality similar to that of ET-based electrodes, and these recording methods enable access to the EMG response of the vocalis muscle that originates from the inner surface of the thyroid cartilage. Studies also indicate that, during surgical manipulation of the trachea, transcartilage, percutaneous, and transcutaneous anterior laryngeal (AL) recording electrodes could be more stable than ET-based surface electrodes and could be equally accurate in depicting RLN stress during IONM. These findings show that these AL electrodes have potential applications in future designs of recording electrodes and support the use of IONM as a high-quality quantitative tool in thyroid and parathyroid surgery. This article reviews the major recent developments of newly emerging transcartilage, percutaneous, and transcutaneous AL recording techniques used in IONM and evaluates their contribution to improved voice outcomes in modern thyroid surgery.

Training Courses in Laryngeal Nerve Monitoring in Thyroid and Parathyroid Surgery- The INMSG Consensus Statement

Intraoperative neural monitoring (IONM) is now an integral aspect of thyroid surgery in many centers. Interest in IONM and the number of institutions that perform monitored thyroidectomies have increased throughout the world in recent years. For surgeons considering the introduction of IONM in their practice, specific training in IONM devices and procedures can substantially shorten the learning curve. The International Neural Monitoring Study Group (INMSG) has been at the forefront of IONM technology and procedural adoption since the introduction of neural monitoring in thyroid and parathyroid surgery. The purpose of this document is to define the INMSG consensus on essential elements of IONM training courses. Specifically, this document describes the minimum training required for teaching practical application of IONM and consensus views on key issues that must be addressed for the safe and reliable introduction of IONM in surgical practice. The intent of this publication is to provide societies, course directors, teaching institutions, and national organizations with a practical reference for developing IONM training programs. With these guidelines, IONM will be implemented optimally, to the ultimate benefit of the thyroid and parathyroid surgical patients.

Advantages of intraoperative nerve monitoring in endoscopic thyroidectomy for papillary thyroid carcinoma

BACKGROUND

This study aimed to evaluate the feasibility and effectiveness of intraoperative nerve monitoring (IONM) for reducing the recurrent laryngeal nerve (RLN) injury risk during central compartment lymph node dissection in endoscopic thyroidectomy of papillary thyroid carcinoma (PTC).

METHODS

The prospective cohort consisted of 69 patients diagnosed with PTC undergoing endoscopic thyroidectomy via the areola approach with (N.=42) or without IONM (N.=27). Multiple logistic regression models were used to assess the association between IONM and postoperative temporary vocal cord palsy or number of retrieved lymph nodes.

RESULTS

IONM was a protective factor against temporary RLN injury. IONM use was positively correlated with number of retrieved lymph nodes (β=1.563, P=0.003). After adjustment for operation type, the result remained significant (β=1.581, P<0.001).

CONCLUSIONS

IONM use reduced the risk of temporary vocal cord palsy and increased the number of retrieved lymph nodes in endoscopic thyroidectomy via the areola approach for patients with PTC.

Use of intraoperative neural monitoring for prognostication of recovery of vocal mobility and reduction of permanent vocal paralysis after thyroidectomy

INTRODUCTION

The benefits of intraoperative neural monitoring (IONM) of recurrent laryngeal nerve (RLN) on post-thyroidectomy vocal cord palsy (VCP) rates are contentious. We wished to study impact of IONM on permanent VCP after thyroidectomy.

METHODS

Retrospective review of prospective series of 1011 (1539 nerves-at-risk) patients undergoing thyroidectomy without (418, group 1) and with (583, group 2) IONM.

RESULTS

There were three recognized nerve injuries in group 1, vs one in group 2 (P = .3). There were no differences in overall VCP rates. However, patients in group 2 with immediate postoperative VCP had higher likelihood of full recovery than patients in group 1 (55 of 56 vs 23 of 29 patients, P = .01), and lower incidence of total permanent VCP (2 of 917 vs 9 of 647 patients, P = .01).

CONCLUSION

Among patients with immediate postoperative VCP after thyroidectomy, IONM is associated with a higher likelihood of regaining normal vocal function. This may be related to better identification of RLN branching in IONM cases.

Effect of intraoperative nerve monitoring on postoperative vocal cord palsy rates after thyroidectomy: European multicentre registry-based study

Background

Intraoperative nerve monitoring (IONM) of the recurrent laryngeal nerve (RLN) predicts the risk of vocal cord palsy (VCP). IONM can be used to adapt the surgical strategy in order to prevent bilateral VCP and associated morbidity. Controversial results have been reported in the literature for the effect of IONM on rates of VCP, and large multicentre studies are required for elucidation.

Methods

Patients undergoing first‐time thyroidectomy for benign thyroid disease between May 2015 and January 2019, documented prospectively in the European registry EUROCRINE®, were included in a cohort study. The influence of IONM and other factors on the development of postoperative VCP was analysed using multivariable regression analysis.

Results

Of 4598 operations from 82 hospitals, 3542 (77·0 per cent) were performed in female patients. IONM was used in 4182 (91·0 per cent) of 4598 operations, independent of hospital volume. Postoperative VCP was diagnosed in 50 (1·1 per cent) of the 4598 patients. The use of IONM was associated with a lower risk of postoperative VCP in multivariable analysis (odds ratio (OR) 0·34, 95 per cent c.i. 0·16 to 0·73). Damage to the RLN noted during surgery (OR 24·77, 12·91 to 48·07) and thyroiditis (OR 2·03, 1·10 to 3·76) were associated with an increased risk of VCP. Higher hospital volume correlated with a lower rate of VCP (OR 0·05, 0·01 to 0·13).

Conclusion

Use of IONM was associated with a low rate of postoperative VCP.

Efficacy of Transcartilaginous Electrodes for Intraoperative Neural Monitoring During Thyroid Surgery

Objectives.

This study was conducted evaluate the efficacy of electromyography (EMG) using transcartilaginous (TC) electrodes through the thyroid cartilage and perichondrium.

Methods.

We prospectively collected EMG data from intraoperative neuromonitoring (IONM) of 54 nerves at risk in 38 patients during thyroidectomy. We followed standardized IONM procedures in all operations. EMG signals from both endotracheal tube (ET) electrodes and TC needle electrodes were recorded simultaneously. We compared the characteristics of the EMG signals and the efficacy of both methods.

Results.

Significantly higher mean EMG amplitudes were recorded by TC electrodes than by ET electrodes in all four-step procedures (V1-R1-R2-V2, P<0.001). Loss of signal (LOS) occurred in five patients in ET electrodes, but in only two patients in TC electrodes. Postoperative laryngoscopy revealed recurrent laryngeal nerve palsy in the two patients who showed LOS from both the ET and TC electrodes, and vocal cord movement was intact in the other three patients. Therefore, the positive predictive values of LOS in ET and TC electrodes were 40% and 100%, respectively.

Conclusion.

EMG recording using TC needle electrodes is feasible and effective, making it a good alternative technique for IONM.

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

[Modern thyroid surgery - the surgeon's endocrine-surgical understanding and his responsibility for the extent of surgery and complication rate]

Die hohe Qualität der Schilddrüsenchirurgie impliziert ein endokrin-chirurgisches Verständnis des Operateurs mit dem Ziel einer bestmöglichen Ergebnisqualität. Das beinhaltet ein befundadäquates Resektionsausmaß und eine möglichst niedrige Komplikationsrate. Der Chirurg sollte frühzeitig in die Operationsindikation eingebunden sein und auch selbst die Diagnostik, speziell den Schilddrüsen- und Halslymphknotenultraschall, sowie die Interpretation der Schnittbild- und nuklearmedizinischen Verfahren beherrschen. Im Besonderen sollte er über zeitgemäße Radikalitätsprinzipien in der Chirurgie Bescheid wissen.

Bei der gutartigen Struma ist eine individualisierte Operationsstrategie anzuwenden: Solitärknoten können auch einer gewebeschonenden Knotenresektion unterzogen werden. Bei multinodulärer Knotenstruma ist nicht zwingend eine totale Thyreoidektomie notwendig, die Vermeidung eines permanenten Hypoparathyreoidismus hat Priorität. Bei Rezidivstrumen ist oft die einseitige Operation des dominanten Befundes zu bevorzugen. Auch besteht zunehmend der Trend, die Indikation zur Entfernung der Schilddrüsenlappen seitengetrennt zu stellen. Die Basedow Struma erfordert eine Thyreoidektomie. Auch die hypertrophe Thyreoiditis Hashimoto kann eine Operationsindikation darstellen.

Die Radikalitätsprinzipien bei maligner Struma haben sich ebenfalls deutlich gewandelt als auch die strenge Indikation zur Radiojodtherapie. Das gilt speziell für papilläre Mikrokarzinome und minimal invasive follikuläre Tumortypen. Selbst bei medullären Schilddrüsenkarzinom stehen die Radikalitätsprinzipien im Hinblick auf synchrone oder metachrone laterale Halsdissektion in Diskussion.

Der Hypoparathyreoidismus stellt derzeit das Hauptproblem in der radikalen Schilddrüsenchirurgie dar. Recurrensparese und Nachblutung sind durch die subtile Operationstechnik selten geworden. Spezielle extrazervikale Operationszugänge sind nach wie vor in der Erprobungsphase und unter strengen Studienbestimmungen nur Zentren vorbehalten. Die Radiofrequenzablation stellt für gewisse Läsionen wie Zysten und autonome Adenome bei chirurgischer Kontraindikation ein alternatives Ablationsverfahren dar.

Intraoperative Neuromonitoring in Thyroid Surgery: An Efficient Tool to Avoid Bilateral Vocal Cord Palsy

OBJECTIVES

This study aimed to analyze the effects of intraoperative neuromonitoring (IONM) on the prevalence of vocal cord palsy (VCP) in thyroid surgery.

METHODS

Data from 493 patients (839 nerves at risk [NAR]) who underwent thyroid surgery between July 2014 and May 2016 were retrospectively evaluated. The patients were divided into 2 groups: Group 1 (G1) consisted of patients who underwent surgery without IONM, whereas group 2 (G2) consisted of patients who underwent surgery with IONM. The surgical techniques were identical, and experienced surgeons performed the procedures in both groups. Intraoperative neuromonitoring was performed in compliance with the International Neural Monitoring Guidelines.

RESULTS

In total, 211 patients (170 female, 41 male) with 360 NAR were included in G1, and 282 patients (220 female, 62 male) with 479 NAR were included in G2. The number of VCP per NAR in G1 and G2 was 33 (9.2%) and 27 (5.6%), respectively (P = .005). The number of transient VCP per NAR in G1 and G2 was 27 (7.5%) and 23 (4.8%; P = .230), respectively. The number of permanent VCP per NAR in G1 and G2 was 6 (1.7%) and 4 (0.8%; P = .341), respectively. Bilateral VCP was detected in 4 (2.7%) patients in G1, whereas there was no patient with bilateral VCP in G2 (P = .033).

CONCLUSIONS

Intraoperative neuromonitoring may decrease the incidence of total VCP and prevent the development of bilateral VCP, which has unfavorable results for both patients and health-care professionals.

Risk of Permanent Hypoparathyroidism After Total Thyroidectomy for Benign Disease: A Nationwide Population-based Cohort Study From Sweden

OBJECTIVE

To investigate the prevalence and risk factors for permanent hypoparathyroidism after total thyroidectomy for benign disease in a population-based setting with data independent of input of complication data.

SUMMARY OF BACKGROUND DATA

The reported rate of permanent hypoparathyroidism is highly variable and mostly rely on reported complication data from national or institutional registries.

METHODS

All patients who underwent total thyroidectomy in Sweden from 2005 to 2015 were identified through Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery and the Swedish National Patient Register. Patients were matched to outcome data from the Swedish Prescribed Drug Register. Permanent hypoparathyroidism was defined as treatment with calcium and/or active vitamin D more than 1 year after surgery.

RESULTS

Seven thousand eight hundred fifty-two patients were included and 938 (12.5%) developed permanent hypoparathyroidism. The risk was lower in patients registered in the quality register (11.0% vs 16%, P < 0.001). In a multivariable analysis there was a higher risk of permanent hypoparathyroidism in patients with parathyroid autotransplantation [Odds ratio (OR) 1.72; 95% confidence interval 1.47-2.01], center-volume <100 thyroidectomies per year (OR 1.22; 1.03-1.44), age above 60 year (OR 1.64; 1.36-1.98) and female sex (OR 1.27; 1.05-1.54). Reported data from the quality register only identified 178 of all 938 patients with permanent hypoparathyroidism.

CONCLUSION

The risk of permanent hypoparathyroidism after total thyroidectomy was high and associated with parathyroid autotransplantation, higher age, female sex and surgery at a low volume center. Reported follow-up data might underestimate the rate of permanent hypoparathyroidism.

Single gland excision for MEN1-associated primary hyperparathyroidism

IMPORTANCE

Guidelines advocate subtotal parathyroidectomy (SPTX) or total parathyroidectomy with autotransplantation (TPTX) with bilateral cervical thymectomy for primary hyperparathyroidism (pHPT) associated with multiple endocrine neoplasia type 1 (MEN1). However, both procedures are associated with a significant risk of permanent hypoparathyroidism.

OBJECTIVE

The aim of the current study was to compare long-term results of either single gland excision (SGE, 1-2 glands), SPTX and TPTX for the treatment of MEN1-associated pHPT.

DESIGN AND SETTING

Data of genetically confirmed MEN1 patients who underwent surgery for pHPT between 1987 and 2017 were retrieved from a prospective database and were retrospectively analysed.

RESULTS

Eighty-nine MEN1 patients underwent either TPTX (n = 38, 42.7%), SPTX (n = 23, 25.8%) or SGE (n = 28, 31.5%). The rate of disease persistence after initial surgery was 2.6%, 0% and 14.2% in the TPTX, SPTX and SGE groups, respectively. After median follow-up of 112 (range 7-411) months, the rate of recurrent pHPT was significantly higher in the SGE group (n = 19, 21.3%) compared with the TPTX (n = 4, 4.4%, P = .001) and the SPTX (n = 9, 10.1%, P = .03) groups. Analysis of the recurrence-free time among the surgical groups revealed a significant difference (P = .036). The median time to recurrence was significantly shorter after SGE (101, range 3-301 months) than after SPTX (139, range 28-278 months, P = .018) and TPTX (204, range 75-396 months, P = .049). Twelve (32%) patients who underwent TPTX developed permanent hypoparathyroidism compared with only 4 (17%, P = .06) in the SPTX and 0 in the SGE group (P = .001).

CONCLUSION

Given the high rate of postoperative permanent hypoparathyroidism after TPTX and SPTX, SGE is a valid option for the treatment of MEN1-associated pHPT.

Intraoperative nerve monitoring in endocrine surgery: prevalence and reasons for its use in Australia and New Zealand

BACKGROUND

Intraoperative nerve monitoring (IONM) has increasingly been used in thyroid surgery by general, endocrine and head and neck surgeons. The purpose of this paper was to explore the prevalence and reasons for the usage of IONM in endocrine surgery in Australia and New Zealand.

METHODS

A survey was sent to general surgeons registered with the Royal Australasian College of Surgeons involved in endocrine surgery and members of the Australian and New Zealand Endocrine Surgeons. Users were divided into surgeon type, area of work, hospital type and volume of surgery. These data were analysed with univariate and multivariate logistic regression models.

RESULTS

Significant differences in IONM usage levels were observed between endocrine and general surgeons, area of work and volume of surgery performed. Endocrine surgeons are significantly more likely to use IONM than general surgeons. Surgeons who work in tertiary hospitals are more likely to use IONM as compared to those working in district hospitals. Surgeons who perform less than 100 thyroidectomies were more likely to be users of IONM.

CONCLUSION

IONM is not routinely used in thyroid surgery in Australia and New Zealand. The main reasons for the use of IONM given in our study by routine users were to establish familiarity of equipment and medicolegal reasons. Selective users chose as the most common reasons, a documented pre-existing unilateral nerve paresis or a hostile surgical field. Non-users stated that there was conflicting evidence that it improves outcomes and increased costs.

Surgical management of the compromised recurrent laryngeal nerve in thyroid cancer

Surgical management of thyroid cancer requires careful consideration of the recurrent laryngeal nerve and its impact on glottic function. Management of the compromised recurrent laryngeal nerve is a complex task, requiring synthesis of multiple elements. The surgeon must have an appreciation for preoperative recurrent laryngeal nerve function, intraoperative anatomic and electromyographic information, disease characteristics, and relevant patient factors. Preoperative clinical evaluation including preoperative laryngoscopy and assessment of recurrent laryngeal nerve risk is essential to formulating a surgical plan and providing appropriate patient counseling. Intraoperative neuromonitoring information has significant implications for surgical management of the injured or invaded recurrent laryngeal nerve and informs strategy with respect to staging of bilateral surgery. Disease characteristics and patient-related factors, including patient preference, must be considered with intraoperative decision-making. Multidisciplinary discussion and patient communication are essential for effective management and successful surgical outcome.

Surgical management of cytologically indeterminate thyroid nodules

Nodules in the thyroid are frequent. Preoperative investigations including fine-needle cytology and ultrasound cannot in all patients rule out malignancy. Thus, surgical excision for histopathologic examination is often needed. In this narrative review, we examine aspects of the surgical management of indeterminate thyroid nodules, using a comprehensive review of the available literature. The authors manually searched PubMed for relevant literature, including recently published guidelines. Hemithyroidectomy without lymph node dissection remains the recommended management in indeterminate thyroid nodules, i.e., the complete removal of one lobe of the thyroid, for indeterminate thyroid nodules, defined as nodules with fine-needle cytology fulfilling the criteria of Bethesda III or IV categories. At surgery, it is important to preserve the recurrent and superior laryngeal nerves, and intraoperative neuromonitoring is a useful adjunct. Recent data also suggest that parathyroid autofluorescent techniques are promising tools for parathyroid preservation. There is still lack of specific preoperative investigations to rule in or out central lymph node metastasis. Intraoperative frozen section of lymph nodes can be valuable, but prophylactic or diagnostic central lymph node dissection is not routinely recommended. Outcomes after thyroid surgery are better with high-volume surgeons and institutions. Surgery is probably best performed by high-volume surgeons in institutions with on-site expert pathologists and with technical adjuncts available for nerve and parathyroid preservation. Day-care surgery may be an option for selected patients.

Impact of continuous intraoperative vagus stimulation on intraoperative decision making in favor of or against bilateral surgery in benign goiter

The advent of continuous vagus stimulation (CVS), eliminating lag time between nerve preparation with potential trauma and stimulation, has transformed the intraoperative surgical strategy in thyroid surgery. Continuous intraoperative nerve monitoring empowers the surgeon to be optimally aware of traction-related injury to the recurrent laryngeal nerve (RLN). Electromyographic precursor lesions, called combined events, prompt surgeons to cease harmful surgical maneuvers and release the nerve before damage to the nerve is established. Complete RLN recovery, defined as restitution of the nerve amplitude to ≥50% of baseline, assures the surgeon that it is safe to pursue completion surgery of the contralateral side in one procedure. If this restitution is incomplete or absent (<50% of amplitude baseline) immediate vocal cord paralysis is likely and it is advisable to delay completion surgery until the nerve has fully recovered. This review summarizes the tremendous progress made in this dynamic field, delineating the extent to which CVS has changed the landscape: tailoring intraoperative decision making to determine the safest course of action for patients with benign goiter.

Vocal cord dysfunction following esophageal atresia and tracheoesophageal fistula (EA/TEF) repair

BACKGROUND

The purpose of this study was to determine risk factors and long-term outcomes in patients with esophageal atresia +/-tracheoesophageal fistula (EA/TEF) with vocal cord dysfunction (VCD) owing to recurrent laryngeal nerve (RLN) injury.

METHOD

A retrospective chart review was performed for EA/TEF patients repaired at our institution from 1999 to 2014 (REB #1000032265).

RESULTS

Of 197 patients, 22 (11.2%) were diagnosed with VCD by indirect laryngoscopy following EA/TEF repair. Aspiration was documented on video swallow study for 21 patients, and as a result, 13 required thickened feeds and 8 required gastrostomy tube feeds. Of the 16 H-type TEF patients, 8 (50%) had VCD. Following discharge, 20 (90.9%) patients with VCD eventually tolerated full feeds orally without aspiration but only 8 (36.4%) had documented recovery of vocal cord movement at long-term follow up (mean 452 days). Overall, patients with VCD were more likely to have feeding modifications, increased exposure to radiological studies, and increased frequency of Otolaryngology follow-up compared to EA/TEF patients without VCD.

CONCLUSION

EA/TEF patients are at risk for VCD. Clinical improvement did not always correlate with recovery of VC motion. Strategies to minimize RLN damage will improve outcomes and quality of life for EA/TEF patients.

LEVEL OF EVIDENCE

Level III.

Increased prevalence of neural monitoring during thyroidectomy: Global surgical survey

OBJECTIVE

To investigate intraoperative nerve monitoring (IONM) use among thyroid surgeons.

METHODS

A 25-question survey was used to assess attitudes regarding IONM use. Surveys were sent to surgeons registered to the American Academy of Otolaryngology-Head and Neck Surgery, International Association of Endocrine Surgeons, and American Head and Neck Society.

RESULTS

Among 1,015 respondents, 83% reported using IONM (65.1% always using IONM and 18.1% reporting selective use). For selective users, a majority reported using IONM for reoperative cases (95.1%) and in cases with preoperative vocal cord paralysis (59.8%). When comparing location, there was a significant difference in IONM implementation (P < 0.001), with 70.4% of North American responders using it ubiquitously compared to 27.4% of non-North American responders. Preoperative laryngeal exam was performed more universally by North American surgeons and more selectively by non-North American surgeons (P < 0.001). Other attitudes toward their implementation and the postoperative laryngeal exam were similar. Surgeons ≤45 years of age and those with ≤15 years of practice used IONM more than their peers (P < 0.001). Thyroid surgery volume, fellowship training, and type of practice had no bearing on IONM use.

CONCLUSION

The prevalence of IONM in thyroid and parathyroid surgeries has increased significantly over the past decade, with 83% of surgeons using IONM in some or all cases. Although IONM use may be more ubiquitous in North America, attitudes toward its implementation and pre- and postoperative laryngeal exams are fairly uniform. IONM use is more prevalent among younger surgeons, whereas its use has no correlation with thyroid surgery volume or type of practice.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:1097-1104, 2020.

Quality of Voice and Prognostic Markers for the Recovery of Vocal Fold Paralysis After Thyroid Surgery

Objectives:

This study is set to analyze clinicopathological factors predicting the recovery of unilateral vocal fold paralysis (UVP) in patients after thyroid gland surgery. The quality of voice was additionally assessed in these patients.

Methods:

The charts and videolaryngostroboscopy (VLS) examinations of 84 consecutive patients with a complete UVP after surgery of the thyroid gland were retrospectively reviewed. Patients were divided into 2 groups: patients who fully recovered from vocal fold paralysis and those who failed to recover after a follow-up of 12 months. The quality of voice was analyzed among other things by determining the Voice Handicap Index (VHI).

Results:

The UVP fully recovered in 52 of 84 (61.9%) patients. Positive mucosal waves (pMWs) on the paralyzed side, a minimal glottic gap <3 mm seen at the first postoperative VLS, age ≤50 years, and surgery duration ≤120 minutes were associated factors for a complete recovery of nerve function. The voice parameters improved independently from recovery of the paralysis in 90% of the patients.

Conclusions:

For patients with a poor prognosis of a UVP, early intervention may be beneficial. Thus, predicting factors for a full recovery of vocal fold motion would be a valuable tool. In our cohort, about 60% of recoveries could have been predicted using the above-mentioned parameters. Good quality of voice was independently reached in 90% of the cases.

Complete and incomplete recurrent laryngeal nerve injury after thyroid and parathyroid surgery: Characterizing paralysis and paresis

BACKGROUND

Injury of the recurrent laryngeal nerve and consequent disorder of vocal fold movement is a typical complication in thyroid and parathyroid surgery. During postoperative laryngoscopy we observed not only a complete standstill (vocal fold paralysis), but also a hypomobility (paresis). In this prospective study, we investigated the difference in incidence and prognosis as well as risk-factors, intraoperative neuromonitoring, and symptoms between vocal fold paralysis and vocal fold paresis.

METHODS

Data were prospectively collected and analyzed in a single high-volume thyroid center between 2012 and 2016. Vocal fold paresis was defined as hypomobility in abduction or adduction, a reduction in range and speed of vocal fold movement. Vocal fold paralysis was defined as asymmetry and missing purposeful vocal fold movement.

RESULTS

The study included 4,707 surgeries and 7,992 at-risk nerves at risk. Vocal fold paralysis was diagnosed in 374 patients (4.68% of 7,992 nerves at risk) and vocal fold paresis in 114 patients (1.43%). Exclusively in the paralysis group, 36 patients (0.45%) developed permanent loss of vocal fold function (P < .001). In follow-up, vocal fold paresis patients regain normal vocal fold function significantly earlier than vocal fold paralysis (mean duration: 6.96 ± 6.506 vs 10.77 ± 7,827 weeks) and presented with significantly less symptoms like hoarseness, diplophonia, dysphagia, and dyspnea (68.8% vs 95.9 %). In intraoperative neuromonitoring, vocal fold paresis showed a significantly higher postresectional N. vagus amplitude than vocal fold paralysis patients (0.349 mV vs 0.114 mV, P < .001).

CONCLUSION

After thyroidectomy, vocal fold paresis must be distinguished from vocal fold paralysis and should be implemented as a separate outcome parameter in the postoperative quality assessment.

Safety and feasibility of a novel recurrent laryngeal nerve monitoring technique

OBJECTIVES/HYPOTHESIS

Continuous intraoperative nerve monitoring (CIONM) during thyroidectomy is promising technology that may reduce the incidence of recurrent laryngeal nerve (RLN) injuries. However, the current technique for CIONM, in which a stimulating probe is placed on the vagus nerve, has not been widely adopted because of concerns regarding its invasiveness and safety. A new method with the lead positioned on the RLN may overcome these objections and promote greater adoption of CIONM. This study was conducted to serve as the first step in determining the safety and feasibility of an RLN-based CIONM approach.

STUDY DESIGN

Case series with planned data collection.

METHODS

Fifty patients scheduled to undergo thyroidectomy were enrolled. In all cases, after identification of the RLN, a lead designed for CIONM was placed on the nerve. The lead was then left in place for a minimum of 2 minutes, and CIONM data were recorded. Laryngeal electromyographic (EMG) characteristics were assessed just before the lead was placed on the RLN and after it was removed. Pre- and postoperative fiberoptic laryngoscopy was performed to assess vocal cord function in all patients.

RESULTS

In 49 patients (98%), the probe was successfully positioned on the RLN, and CIONM data were generated. On average, 1.4 attempts per patient were required to properly place the lead. No accidental dislodgements of the lead occurred during the experiments. No patients demonstrated significant EMG changes from baseline after manipulation and stimulation of the RLN. The average CIONM time was 175.7 s (range, 138-212 s), and the average CIONM amplitude and latency were 675.2 µV (range, 211.0-1405.2 µV) and 1.8 ms (1.25-1.9), respectively. All patients had normal bilateral vocal cord function preoperatively and at the first postoperative visit.

CONCLUSIONS

This study demonstrates the apparent safety and viability of a CIONM technique using a lead placed directly on the RLN. Future investigations are warranted of this promising method, which may promote more widespread adoption of CIONM during thyroidectomy to reduce RLN injuries.

LEVEL OF EVIDENCE

4 Laryngoscope, 2018.

AHNS Series: Do you know your guidelines? Optimizing outcomes in reoperative parathyroid surgery: Definitive multidisciplinary joint consensus guidelines of the American Head and Neck Society and the British Association of Endocrine and Thyroid Surgeons

BACKGROUND

Revision parathyroid is challenging due to possible diagnostic uncertainty as well as the technical challenges it can present.

METHODS

A multidisciplinary panel of distinguished experts from the American Head and Neck Society (AHNS) Endocrine Section, the British Association of Endocrine and Thyroid Surgeons (BAETS), and other invited experts have reviewed this topic with the purpose of making recommendations based on current best evidence. The literature was also reviewed on May 12, 2017. PubMed (1946-2017), Cochrane SR (2005-2017), CT databases (1997-2017), and Web of Science (1945-2017) were searched with the following strategy: revision and reoperative parathyroidectomy to ensure completeness.

RESULTS

Guideline recommendations were made in 3 domains: preoperative evaluation, surgical management, and alternatives to surgery. Eleven guideline recommendations are proposed.

CONCLUSION

Reoperative parathyroid surgery is best avoided if possible. Our literature search and subsequent recommendations found that these cases are best managed by experienced surgeons using precision preoperative localization, intraoperative parathyroid hormone (PTH), and the team approach.

A Review of Methods for the Preservation of Laryngeal Nerves During Thyroidectomy

The recurrent laryngeal nerve (RLN) provides motor innervation to the abductor and adductor muscles of the vocal cord, whereas the external branch of the superior laryngeal nerve (EBSLN) provides motor innervation to the cricothyroid muscle, which is the tensor muscle of the vocal cord. Both the RLN and the EBSLN are anatomically close to the thyroid and are therefore at risk of injury during thyroidectomy. These 2 laryngeal nerves must be carefully preserved during surgery to ensure that the function of the vocal cord is not impaired. Currently, complete exposure of the RLN during thyroidectomy is accepted as the gold standard method for the preservation of RLN. Sufficient knowledge of surgical anatomy, clinical experience, and meticulous surgical techniques are key factors in the identification and safe dissection of the RLN. During a thyroidectomy, the RLN can be identified using four different approaches, depending on the type of thyroid growth and choice of the surgeon: There are lateral, inferior, superior, and medial approaches.

The lateral approach is the most commonly used technique in primary thyroid surgery. The RLN is usually found by dissection around the inferior thyroid artery at the level of the middle lobe of the thyroid. RLN is generally found at the site of its entry into the neck region devoid of scar formation when the inferior approach is used especially in cases with secondary surgery. The superior approach is recommended for patients with an huge goiter or large substernal goiter. In this approach, the upper pole of the thyroid is first released and then pulled forward and laterally, and the RLN is exposed on the nerve’s entry point (NEP), into the larynx, under the cricopharyngeus muscle. The medial approach is preferred for patients with substernally or retropharyngeally enlarged goiters. In this approach, the isthmus is first dissected and divided, and then the isthmus and the medial part of the lobe are dissected away from the trachea to reveal the anterolateral part of the trachea. The fibers between the lateral aspect of the second or third tracheal rings and the thyroid, and the fibers of the Berry ligament are gradually dissected cranially, to allow RLN to enter into the field of view lateral to the trachea. The preservation of the anatomical integrity of the RLN does not indicate that its functional integrity is also preserved. IONM is a tool for the functional assessment of RLN, and so this method is an addition to visually identifying RLN, which is the gold standard. IONM significantly contributes to visual identification of the RLN, determination of its anatomical variations, intraoperative recognition of RLN injury, prevention of bilateral vocal cord paralysis, and detection and preservation of electrical activity in the nerve in patients with preoperative vocal cord paralysis.

Although there is no standardized method for the preservation of the EBSLN, 3 methods have been defined during the release of the upper pole of the thyroid. These methods involve dividing the branches of the superior thyroidal artery one by one on the capsule without visually identifying the EBSLN, searching and visually identifying the EBSLN before the dissection of the upper pole vessels, or detecting the EBSLN and dissecting the upper pole under the guidance of IONM. IONM also significantly contributes to the detection and confirmation of the EBSLN and dissection and preservation of the upper pole of the thyroid gland.

Effect of nerve monitoring on complications of thyroid surgery

OBJECTIVE:

The most frequent and critical complications of thyroid surgery are recurrent laryngeal nerve palsy and hypocalcemia. In first years of the 21st century, intraoperative neuromonitoring (IONM) was introduced as a new technique to avoid the recurrent laryngeal nerve (RLN) injury. However, the role and the benefits of IONM are still controversial. In this study, we aimed to compare the postoperative complication rates during thyroid surgery with IONM usage (Group 1) and conventional direct visual technique without IONM usage (Group 2).

METHODS:

We conducted retrospective review of all patients undergoing thyroid surgery in Lütfiye Nuri Burat State Hospital General Surgery Department between 2014 and 2016 years. Patients have been classified in to two groups: Group 1 and 2.

RESULTS:

Overall, 191 patients were included in the study; Group 1 comprised 79 patients and Group 2 comprised 112 patients. Unilateral RLN paralysis was observed in 7 patients in Group 1 (8.9%) and 15 patients in Group 2 (13.4%) without any significant difference between the groups (p=0.368). Hypocalcemia was encountered in 5 patients (6.3%) in Group 1 and 18 patients (16.1%) in Group 2; this difference was statistically significant (p=0.045). Other complications (such as hematoma and suture reaction) were not significantly different. Operation time was found to be significantly shorter in Group 1 (Mean time, 93.08 min) than in Group 2 (116.54 min) (p=0.03).

CONCLUSION:

Proven effect of IONM on RLN paralysis is still controversial. However, easy identification of RLN, which gives more confidence to surgeon, and shorter operation time may be factors to lower hypocalcemia rates.