Quantitative study of voice dysfunction after thyroidectomy

Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA): Influences on the Voice Changes and Swallowing Function Disorders

OBJECTIVE

The aim of this study was to evaluate the influence of transoral endoscopic thyroidectomy vestibular approach (TOETVA) on voice changes and swallowing function disorders.

MATERIALS AND METHODS

We retrospectively reviewed 215 patients who underwent thyroid surgery with TOETVA (105 cases, endoscopic group) and open approach (110 cases, open group). Major outcomes, the changes in voice and swallowing function in the 2 groups of patients before and after surgery were analyzed by using both subjective and objective evaluation indexes. Subjective evaluation indexes included the Voice Handicap Index, voice GRBAS (Grade, Roughness, Breathiness, Asthenia, Strain) classification, and swallowing impairment score; the objective indicators included the fundamental frequency (F0), fundamental frequency perturbation (jitter), amplitude perturbation (shimmer), and maximum phonation time.

RESULTS

In terms of subjective evaluation indexes, there were no significant differences (all P> 0.05) between the groups regarding Voice Handicap Index (1 and 3 mo after surgery) and GRBAS (1 and 3 mo after surgery). The incidence rates of swallowing disorder in the endoscopic group were higher than that in the open group according to the outcomes of swallowing impairment score at 1 and 3 months after surgery (both P< 0.05). In addition, no significant changes in terms of jitter, shimmer, and maximum phonation time in both groups of patients at 1 and 3 months after surgery compared with their preoperative values (all P> 0.05).

CONCLUSIONS

Voice and swallowing disorders may occur in some patients, either TOETVA or open thyroid surgery, which in most cases will recover within 3 months after surgery. The time to swallowing function recovery is relatively prolonged in patients following TOETVA, which may be probably associated with neck adhesion and fixation after the operation.

Voice Disorders after Total Thyroidectomy: Prospective Evaluation by Patient Self-Assessment, Indirect Laryngoscopy and Ultrasonography

Voice alterations after thyroidectomy with mobile vocal folds are common. Ultrasonography has been used to assess the mobility of the vocal folds after thyroidectomy. Fifty-four patients underwent thyroidectomy. Indirect laryngoscopy, ultrasonography, and GRBAS (grade, roughness, breathiness, asthenia, strain) scoring were performed preoperatively, 3 days, 2 and 6 months, postoperatively. On the third postoperative day, the mobility of the vocal folds was preserved in 52 patients and pareses were recorded in 2 patients. All patients after thyroidectomy noted the presence of voice alteration in the absence of the postoperative paresis of the vocal folds. On the third postoperative day, the voice was impaired by all criteria of the GRBAS scale, but mainly due to roughness (85%). Sixth month postoperatively, 62% of the subjects considered the voice to be altered. Asthenia was observed in 39%. On the third postoperative day indirect laryngoscopy revealed the unchanged vocal folds, the edema and the shortening of one of the vocal folds in 56%, 42%, and 1.9%. Six months postoperatively, the vocal folds returned to their original form. Indirect laryngoscopy and ultrasonography had 100% concordance in assessing the mobility of the vocal folds. Patients with edema of the vocal folds had a significantly higher mean GRBAS grade than patients without edema. The mean GRBAS score decreased from 3.36 to 0.90, 3 days and 6 months, postoperatively. Voice alteration after thyroidectomy is always present. Postoperative edema represents a likely main cause of voice alteration and resolves within 6 months. Ultrasonography is recommended as alternative to indirect laryngoscopy in assessing of the vocal folds after thyroidectomy.

Use of Prophylactic Steroids to Prevent Hypocalcemia and Voice Dysfunction in Patients Undergoing Thyroidectomy: A Randomized Clinical Trial

Importance

Total thyroidectomy is associated with risks related to temporary hypocalcemia and vocal quality dysfunction. Dexamethasone has been proposed to have a physiological effect on hypocalcemia and voice quality.

Objective

To assess the effect of preoperative dexamethasone used to improve hypocalcemia and postthyroidectomy voice dysfunction.

Design, Setting, and Participants

This double-blind, parallel-group, placebo-controlled randomized clinical trial was conducted from January 15, 2014, to December 31, 2019, at the Department of Surgery, Holy Family Hospital in Rawalpindi, Pakistan. All patients with a benign thyroid condition and no preoperative corrected hypocalcemia and voice or vocal quality dysfunction were included. Patients were excluded if they had previous thyroid or neck surgery, known vocal cord dysfunction on laryngoscopy, hearing or voice problems, a history of gastroesophageal reflux, stomach ulcer disease, or contraindications to steroid use.

Interventions

Corrected serum calcium levels and Voice Analog Score defined and measured preoperatively. The dexamethasone group received a 2-mL intravenous dose of 8 mg of dexamethasone 60 minutes before the induction of anesthesia. In contrast, the placebo group received 2 mL of intravenous normal saline (0.9%) 60 minutes before the induction of anesthesia.

Main Outcomes and Measures

Evidence of hypocalcemia and voice dysfunction. Voice dysfunction was defined as a subjective score of less than 50 on a Voice Analog Score scale of 0 to 100 points.

Results

A total of 192 patients (mean [SD] age, 38.9 [12.4] years; 156 women [81.2%]) were included in the study, with 96 patients randomized to each study group (dexamethasone group, mean [SD] age, 39.2 [12.1] years; 75 women [78.1%]; placebo group, mean [SD] age, 38.5 [12.9] years; 81 women [84.5%]). In the first 24 hours after undergoing thyroidectomy, 47 patients (24.4%) developed hypocalcemia and 18 (9.4%) were symptomatic. At 3 days postthyroidectomy, 4 of 96 patients (4.2%) in the placebo group had hypocalcemia compared with no patients in the dexamethasone group. At 24 hours postthyroidectomy, 8 of 96 patients (8.3%) in the dexamethasone group had voice dysfunction compared with 32 of 96 patients (33.3%) in the placebo group. A total of 40 patients (20.8%) reported voice dysfunction. The absolute reduction in the rate of hypocalcemia at 24 hours was 24% (95% CI, 11.9%-35.2%) and at 3 days was 4.2% (-0.44% to 10.0%). The rate of symptomatic hypocalcemia was 19% lower in the dexamethasone group than in the placebo group (95% CI, 11.1%-27.7%). The rate of voice dysfunction was 25% lower in the dexamethasone group than in the placebo group (95% CI, 13.7%-35.7%).

Conclusions and Relevance

In this randomized clinical trial, a single preoperative dose of dexamethasone was safe and effective in reducing postoperative hypocalcemia and voice dysfunction rates in patients undergoing thyroidectomy.

Trial Registration

ClinicalTrials.gov identifier: NCT04752852.

Objective Analysis Of Voice Quality In Patients With Thyroid Pathology

OBJECTIVE

The goal of this study is to analyze the voice in patients with thyroid pathology through two objective indexes with great diagnostic accuracy. Overall vocal quality was evaluated with the Acoustic Voice Quality Index (AVQI v.03.01) and the breathy voice with the Acoustic Breathiness Index (ABI).

DESIGN

Observational case-control study.

SETTING

Hospital Universitario Nuestra Señora de Candelaria.

PARTICIPANTS

Fifty-eight subjects, 29 controls and 29 thyroidectomy candidates.

MAIN OUTCOME MEASURES

All participants with thyroid pathology completed the Spanish version of Voice Handicap Index-10. Also, patient complaints relating to possible laryngeal dysfunction were assessed through closed questions. A sustained vowel and three phonetically balanced sentences were recorded for each subject (118 samples). AVQI v.03.01 and ABI were assessed using the Praat program. Two raters perceptually evaluated each voice sample by using the Grade parameter of GRABS scale.

RESULTS

Acoustic analysis shows that 55.17% of subjects present values above the pathological threshold of the AVQI, and 58.62% above that of the ABI. Results of the Student's test comparisons of the AVQI and ABI values between the control group and the thyroid group show significantly higher values of AVQI (t_[56]  = -3.85, p < .001) and ABI (t_[54.39]  = -4.82, p < .001) in thyroidectomy candidates.

CONCLUSION

A mild decrease in vocal quality is part of the symptomatology presented by thyroidectomy candidates.

Long-term voice quality outcome after thyroidectomy without laryngeal nerve injury: a prospective 10 year follow up study

PURPOSE

This study investigates the long-term voice outcome of thyroidectomy up to 10 years after the surgery using a longitudinal prospective study design.

METHODS

Eighteen participants (6 men and 12 women, mean age: 54 years) who underwent a thyroidectomy between September 2006 and May 2007 were included in this study. A voice assessment protocol consisting of subjective (videolaryngostroboscopic evaluation, auditory- perceptual evaluation, patients' self-report) and objective voice assessments (maximum performance task, acoustic analysis, voice range profile and Dysphonia Severity Index) was used to evaluate the participants' pre- and postoperative voice. Voice measurements were compared before and one week, six weeks, three months and 10 years after the surgery.

RESULTS

No significant differences over time in auditory-perceptual and objective voice parameters were found, except for shimmer. Only in the first postoperative condition, significantly more patients reported vocal complaints. A progressive amelioration of the vocal folds' movement patterns was observed in the postoperative conditions.

CONCLUSION

The findings of this small longitudinal prospective study suggest that thyroidectomy without laryngeal nerve injury does not cause a permanent deterioration of the laryngeal aspect or function, vocal fold behavior and the self-perceived, perceptual and objective vocal quality. The increase of the shimmer 10 years post-thyroidectomy may be related to vocal aging.

Analysis of voice changes after thyroidectomy using the thyroidectomy-related voice and symptom questionnaire

OBJECTIVE

After thyroidectomy, many patients suffer from voice problems and vague neck discomfort. The Thyroidectomy-related Voice and Symptom Questionnaire (TVSQ) is a self-administered questionnaire used to evaluate pre- and post-operative vocal status as well as throat and neck discomfort. We investigated voice conditions in thyroidectomy patients using the TVSQ as well as correlations between TVSQ responses and objective voice parameters. Also, we examined whether any clinicopathologic or surgical factors affect phonetic change after thyroidectomy.

METHODS

We retrospectively reviewed the records of 242 patients who underwent total thyroidectomy to treat papillary carcinoma between January to December of 2019. Of these, we enrolled 232 who exhibited normal vocal cord mobility after surgery. TVSQ responses and acoustic voice analysis results were examined preoperatively and at 1, 3, and 6 months postoperatively. We subclassified patients into favorable and unfavorable TVSQ groups based on the increase in TVSQ score (△TVSQ ≥20) at 1 month postoperatively. We then investigated the difference of acoustic characteristics between two groups and analyzed the correlations between acoustic parameters and various clinical and surgical factors including pathologic results and lymph node status by subgroup.

RESULT

All acoustic voice parameters except for the noise-to-harmonics ratio were significantly worse at 1 month postoperatively and recovered over time, but the TVSQ score did not recover from the 1-month value until 6 months postoperatively. In the subgroups, among the many clinicopathologic factors examined, advanced N stage (p = 0.002) and high positive total and central-and-lateral-neck lymph node ratios were significantly associated with an increased risk of an unfavorable TVSQ (p = 0.049, 0.027, <0.01, respectively). Among the acoustic parameters, only the changes in TVSQ total score and voice score were correlated with deterioration in jitter and shimmer at 1 month postoperatively. However, the correlations was not statistically significant and had disappeared at 6 months postoperatively.

CONCLUSION

We figured out that TVSQ was able to capture the negative effects of lymph node status and lymph node dissection on vocal outcomes after thyroidectomy. Although there was a weak correlation between worsened perturbation value and TVSQ changes, no other acoustic analysis parameters were statistically significant correlated with the TVSQ score.

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

BACKGROUND

Laryngeal dysfunction after thyroid and parathyroid surgery requires early recognition and a standardized approach for patients that present with voice, swallowing, and breathing issues. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to define the terms "immediate vocal fold paralysis" and "partial neural dysfunction" and to provide clinical consensus statements based on review of the literature, integrated with expert opinion of the group.

METHODS

A multidisciplinary expert panel constructed the manuscript and recommendations for laryngeal dysfunction after thyroid and parathyroid surgery. A meta-analysis was performed using the literature and published guidelines. Consensus was achieved using polling and a modified Delphi approach.

RESULTS

Twenty-two panelists achieved consensus on five statements regarding the role of early identification and standardization of evaluation for patients with "immediate vocal fold paralysis" and "partial neural dysfunction" after thyroid and parathyroid surgery.

CONCLUSION

After endorsement by the AHNS Endocrine Section and Quality of Care Committee, it received final approval from the AHNS Council.

Development and Validation of the Thyroidectomy-Related Voice and Symptom Questionnaire (TVSQ)

OBJECTIVES

Common symptoms after thyroidectomy include voice change and throat and neck discomfort. But no common questionnaire has been developed. This study was performed to evaluate the reliability and validity of the Thyroidectomy-related Voice and Symptom Questionnaire (TVSQ).

METHODS

Fourty items of the TVSQ were divided into 20 items related to the "voice change" and "throat and neck discomfort" subcategories, using item generation. Through a reduction process, 20 items were removed and 20 items were used. For the patients after thyroidectomy, we evaluated the reliability and validity of each of the 20 items through item discrimination, test-retest reliability, concurrent validity, and external validity by comparing normal group and laryngeal disease patients. Also, the patients were compared before as well as 2 and 4 weeks after thyroidectomy.

RESULTS

Item discrimination assessment showed a significant correlation between TVSQ total score and both the TVSQ "voice change" score (r = 0.908**) and TVSQ "throat and neck discomfort" score (r = 0.862**). Test-retest reliability assessment showed a significant correlation between TVSQ total scores at 2 and 4 weeks postoperatively (r = 0.764**). Concurrent validity assessment revealed that the TVSQ showed high correlations with other voice questionnaires (Voice Handicap Index, Reflux Finding Index, and Vocal Track Discomfort Scale; r = 0.538**-0.830**). External validity assessment revealed that the TVSQ was suitable for patients after thyroidectomy (P < 0.000**).

CONCLUSIONS

Validity and reliability tests revealed that the TVSQ was suitable for assessment of the subjective feelings of patients with voice change and throat and neck discomfort after thyroidectomy.

U-shaped strap muscle flap for difficult thyroid surgery

Background

Open thyroidectomy via conventional midline approach can be challenging in complex thyroid surgeries. This study proposes a U-shaped strap muscle flap (USMF) technique that provides adequately wide exposure of the surgical field.

Methods

Strap muscles were cut close to the clavicle and along the anterior margin of both sternocleidomastoid muscles followed by total thyroidectomy in 20 patients as USMF group, and surgical outcomes were compared with 40 patients who had received total thyroidectomy via midline approach.

Results

No patient had postoperative hematoma, vocal cord paralysis, permanent hypocalcaemia, wound infection or flap necrosis. At 2 months post-surgery, objective voice analysis and subjective assessment of voice and swallowing showed no significant difference between groups.

Conclusions

USMF provides superb surgical field exposure, and the voice and swallowing functions after USMF are comparable to those obtained by midline approach. The USMF approach is a feasible option for selective difficult thyroid surgery.

Morbidity following thyroid surgery: acceptable rates and how to manage complicated patients

PURPOSE

The endocrine surgeon and the endocrinologist should standardize how they deal with patients with an indication for thyroidectomy, as the road to surgery starts well before the operation itself. The patient should be thoroughly informed about where and how surgery will be performed, the postoperative improvements that can be expected, and the possibility and incidence of relevant complications. This short review aims at identifying the most common postoperative issues after thyroidectomy, with the relevant therapeutic suggestions.

METHODS

A revision of studies reporting the morbidity of thyroid surgery, involving the largest numbers of patients.

RESULTS

It has been clearly demonstrated that the outcome of thyroid surgery is significantly better when the procedure is performed by an experienced surgeon. Thus, the number of thyroidectomies performed by a surgeon should drive the endocrinologist when referring a patient.

CONCLUSIONS

Despite the surgeon's experience, thyroidectomy is burdened by a relatively high rate of postoperative issues ranging from less severe ones to others causing significant changes in the patient's quality of life. Minor, non-invalidating symptoms have been described in 40% of patients after thyroidectomy (e.g. hoarseness, mild dysphagia, some degree of voice alteration); however, these symptoms usually resolve within a few months of surgery, with or without early treatment. On the other hand, major postoperative complications are observed in a limited number of patients, but in these cases early diagnosis is important to provide the most appropriate postoperative treatment, and thus hasten full recovery or at least achieve the greatest possible improvement.

Comparison Between Patient-Perceived Voice Changes and Quantitative Voice Measures in the First Postoperative Year After Thyroidectomy: A Secondary Analysis of a Randomized Clinical Trial

Importance

Voice changes after thyroidectomy are typically attributed to recurrent laryngeal nerve injury. However, most postoperative voice changes occur in the absence of clinically evident vocal fold paralysis. To date, no study has compared the prevalence, duration, and consequences of voice-related disability from the patient perspective with use of quantitative vocal measures.

Objectives

To assess the quality-of-life consequences of postthyroidectomy voice change from the perspective of patients with thyroid cancer and to compare patient-perceived voice changes with changes in quantitative vocal variables at 5 time points in the first postoperative year.

Design, Setting, and Participants

This prospective mixed methods observational study within a randomized clinical trial occurred at the University of Wisconsin Hospital and Clinics. Participants were 42 patients with clinically node-negative papillary thyroid cancer without a preexisting vocal cord paralysis who were recruited and enrolled from outpatient clinics between June 6, 2014, and March 6, 2017, as part of the ongoing randomized clinical trial.

Intervention

Total thyroidectomy.

Main Outcomes and Measures

Semistructured interviews, symptom prevalence, and instrumental voice evaluations (laryngoscopy, phonation threshold pressure, Dysphonia Severity Index, and Voice Handicap Index) occurred at baseline (n = 42) and 2-week (n = 42), 6-week (n = 39), 6-month (n = 35), and 1-year (n = 30) postoperative time points.

Results

Participants had a mean age of 48 years (interquartile range, 38-58 years; age range, 22-70 years) and were mostly female (74% [31 of 42]) and of white race/ethnicity (98% [41 of 42]). Impaired communication was the primary theme derived from patient interviews from before thyroidectomy to after thyroidectomy. Voice changes were perceived by 24 participants at 2 weeks after thyroidectomy. After surgery, voice symptoms were prevalent and persisted for 50% (21 of 42) of participants out to at least 1 year of follow-up. Quantitative vocal perturbations were detected in the Dysphonia Severity Index and Voice Handicap Index at the 2-week follow-up but returned to baseline levels by the 6-week follow-up visit.

Conclusions and Relevance

Voice changes are common after surgery for papillary thyroid cancer and affect quality of life for many patients out to 1 year of follow-up. Directly querying patients about postoperative voice changes and questioning whether commonly used aerodynamic and acoustic variables detect meaningful voice changes are important in identifying patients whose quality of life has been affected by postthyroidectomy dysphonia.

Trial Registration

ClinicalTrials.gov Identifier: NCT02138214.

Long-term quality of voice is usually acceptable after initial hoarseness caused by a thyroidectomy or a parathyroidectomy

Background

Vocal cord (VC) palsy following a thyroidectomy or parathyroidectomy can result in significant morbidity for the patient. We aimed to investigate the incidence of VC palsy in a tertiary referral Institution, track the management of these cases and record the long-term outcomes and VC recovery rates.

Methods

Retrospective review of all thyroidectomy/parathyroidectomy operations performed over 11 years. Patients with an unequivocal hoarse voice postoperatively were included. We analysed the patient's clinical characteristics and voice outcomes, operative, pathology and laryngoscopy reports during their follow-up.

Results

Ten patients fitted the inclusion criteria and were analysed. Median age at date of operation was 47.5 years (range, 16-81 years) and the M:F ratio was 1:2.3 (M:3, F:7). The median FU was 62.5 months (range, 12-144 months). The median hospital stay was 1.5 days (range, 1-87 days). There were 7 recurrent laryngeal nerve (RLN) injuries by manipulation, 1 case of RLN resection, 1 inadvertent division (with primary nerve repair) and 1 RLN was shaved off the thyroid. Long-term voice outcomes for the 7 patients with an RLN manipulation injury were: 3/7 patients had normal voice, 3/7 had moderate hoarseness and 1/7 had long-term hoarseness. The long-term voice outcome of the patient with RLN shaving off the thyroid gland was excellent while the 2 remaining patients (RLN resection and inadvertent division) needed 12 and 18 months respectively to achieve a normal quality of voice. Four out of the 10 patients had permanent VC palsy in the long-term and their voice outcomes varied: 1 patient had a normal voice, 2 patients had moderate hoarseness and 1 patient had persistent hoarseness. Only 1/10 patients did not show any voice improvement after 12 months.

Conclusions

In the vast majority of cases post-operative hoarseness due to RLN palsy improves in the long-term, albeit voice may not return completely to normal.

Development of a binational thyroid cancer clinical quality registry: a protocol paper

INTRODUCTION

The occurrence of thyroid cancer is increasing throughout the developed world and since the 1990s has become the fastest increasing malignancy. In 2014, a total of 2693 Australians and 302 New Zealanders were diagnosed with thyroid cancer, with this number projected to rise to 3650 in 2018. The purpose of this protocol is to establish a binational population-based clinical quality registry with the aim of monitoring and improving the quality of care provided to patients diagnosed with thyroid cancer in Australia and New Zealand.

METHODS AND ANALYSIS

The Australian and New Zealand Thyroid Cancer Registry (ANZTCR) aims to capture clinical data for all patients over the age of 16 years with thyroid cancer, confirmed by histopathology report, who have been diagnosed, assessed or treated at a contributing hospital. A multidisciplinary steering committee was formed which, with operational support from Monash University, established the ANZTCR in early 2017. The pilot phase of the registry is currently operating in Victoria, New South Wales, Queensland, Western Australia and South Australia, with over 20 sites expected to come on board across Australia in 2018. A modified Delphi process was undertaken to determine the clinical quality indicators to be reported by the registry, and a minimum data set was developed comprising information regarding thyroid cancer diagnosis, pathology, surgery and 90-day follow-up.

FUTURE PLANS

The establishment of the ANZTCR provides the opportunity for Australia and New Zealand to further understand current practice in the treatment of thyroid cancer and identify variation in outcomes. The engagement of endocrine surgeons in supporting this initiative is crucial. While the pilot registry has a focus on early clinical outcomes, it is anticipated that future collection of longer term outcome data particularly for patients with poor prognostic disease will add significant further value to the registry.

Thyroidectomy Then and Now: A 50-Year Australian Perspective

BACKGROUND

Since the mid-1800s, thyroidectomy has transformed from a procedure associated with high to near-zero mortality. Nonetheless, surgeons must continue to strive to improve patient care. Using historical records and contemporary data, this study compares the practice and outcomes of thyroid surgery at a tertiary institution during two periods, 50 years apart.

METHODS

'The Alfred Hospital Clinical Reports' recorded all cases of surgically managed thyroid disease from 1946 to 1959. These historical cases were compared to contemporary thyroidectomy cases at the Alfred Hospital from 2007 to 2016. Cases were compared for surgical indication and post-operative outcomes.

RESULTS

There were 746 patients in the historical group (mean age 53 years; 87% female) and 787 patients in the contemporary group (mean age 52 years; 80% female). The most common indication for thyroidectomy in both groups was non-toxic nodular goitre. A greater proportion of the contemporary group were diagnosed with thyroid malignancy (27% vs. 8%; p < 0.001). The contemporary group recorded significantly fewer cases of thyrotoxic crisis (2.1% vs. 0%; p = 0.001), permanent nerve palsy (4.6% vs. 0.4%; p < 0.001) and bilateral nerve palsy (1.2% vs. 0%; p = 0.01). There were no mortalities in the contemporary group, while the historical data recorded three deaths (0.44%).

CONCLUSIONS

This study compared thyroid surgery in two cohorts separated by a 50-year period. While it is not surprising that outcomes of thyroidectomy have improved, this study uniquely demonstrates trends of thyroid surgery over time and areas in which further improvements may be made.

Association Between Age and Patient-Reported Changes in Voice and Swallowing After Thyroidectomy

OBJECTIVES

Despite intact recurrent laryngeal nerves, patient-reported voice and swallowing changes are common after thyroidectomy. The association between patient age or frailty status and these changes is unknown. The aim of this study was to evaluate the impact of age and frailty on the incidence of voice and swallowing alterations after thyroidectomy.

METHODS

We performed an institutional review board (IRB)-approved retrospective review of consecutive patients who underwent total thyroidectomy with intraoperative recurrent laryngeal nerve (RLN) monitoring at a single institution between January 2014 and September 2016. Patients with RLN injury were excluded. After data extraction, a modified frailty index (mFI) was calculated for each patient. The association among risk factors, including age, mFI, prior history of neck surgery, frequent voice use, presence of malignancy or gastroesophageal reflux disease, and smoking status and reported voice and/or swallowing changes was examined.

RESULTS

Of 924 patients undergoing thyroidectomy, 148 (16.0%) reported only changes in voice; 52 (5.6%) reported only difficulty in swallowing; and 26 (2.8%) reported changes with both voice and swallowing. On multivariate analysis, we found a significant increase in voice or swallowing alterations up to the age of 50 years (5% increased odds per year), after which these changes plateaued. We found that mFI was not associated with voice or swallowing changes.

CONCLUSION

Age ≥ 50 years is independently associated with the development of voice or swallowing changes after thyroidectomy, despite intact RLN. Additional prospective studies are needed to validate these findings, further define this association, and identify risk factors for developing these changes.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:519-524, 2019.

Contribution of intraoperative neural monitoring to preservation of the external branch of the superior laryngeal nerve: a randomized prospective clinical trial

PURPOSE

The purpose of this study was to evaluate the effect of intraoperative neuromonitoring (IONM) on the injury rate of the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy.

METHODS

A total of 133 consenting patients (98 female, 35 male; mean age, 45.6 ± 11.7 years) undergoing thyroidectomy were randomly assigned to 2 groups. In group 1 (n = 65 patients, 105 nerves), superior thyroid pole dissection was performed with no attempt to identify the EBSLN; in group 2 (n = 68 patients, 106 nerves), IONM was used to identify the EBSLN during surgery. EBSLN function was evaluated by intraoperative electromyography of the cricothyroid muscle. The EBSLN Voice Impairment Index-5 (VII-5) was conducted preoperatively and at 1, 3, and 6 months postoperatively. The primary outcome was the prevalence of EBSLN injury. The secondary outcomes were the identification rate of the EBSLN using IONM and changes in postoperative voice performance.

RESULTS

EBSLN injury was detected in eight (12.3%) patients and nine (8.6%) nerves in group 1 and in one (1.5%) patient and one (0.9%) nerve in group 2 (patients, p = 0.015; nerves, p = 0.010). IONM contributed significantly to visual (p < 0.001) and functional (p < 0.001) nerve identification in group 2. The VII-5 indicated more voice changes in group 1 than 2 at 1, 3, and 6 months postoperatively (p = 0.012, p = 0.015, and p = 0.02, respectively).

CONCLUSION

IONM contributes to visual and functional identification of the EBSLN and decreases the rate of EBSLN injury during superior pole dissection. Routine use of IONM to identify the EBSLN will minimize the risk of injury during thyroidectomy.