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

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

The effect of strap muscle transection on voice and swallowing changes after thyroidectomy in patients without laryngeal nerve injury.

INTRODUCTION: Voice and swallowing symptoms are frequently reported after thyroidectomy even without laryngeal nerve injury. We aimed to evaluate the effect of strap muscle transection on voice and swallowing outcome after thyroidectomy. METHODS: Group 1 (G1) consisted of 17 patients who had their strap muscles transected during thyroidectomy and group 2 (G2) consisted of 17 patients who had their strap muscles preserved during thyroidectomy. None of the patients had laryngeal nerve injury. Voice impairment scores (VIS) and swallowing impairment scores (SIS) were obtained preoperatively and at 1 week and 1, 3 and 6 months postoperatively. Pre- and postoperative vocal cord examinations were performed for all patients. The external branch of the superior laryngeal nerve (EBSLN) was evaluated by intraoperative cricothyroid muscle electromyography. RESULTS: There was no significant difference in VIS and SIS between the two groups. At postoperative week 1, the VIS and SIS for each group were above preoperative values (G1: p = 0.005 and p = 0.035; G2: p = 0.031, p = 0.346, for VIS and SIS respectively). The VIS and SIS scores at 6 months postoperatively were significantly lower than those of the first week postoperatively (G1: p = 0.04 and p = 0.001; G2: p = 0.022 and p = 0.034 respectively) and similar to preoperative values (G1: p = 0.924 and p = 0.086; G2: p = 0.822 and p = 0.187 respectively). CONCLUSION: Although voice and swallowing complaints increased in the early postoperative period even without recurrent laryngeal nerve and EBSLN injuries, these symptoms are not related with the strap muscle transection.

Short-term Outcomes of Robot-assisted Minimally Invasive Esophagectomy Compared With Thoracoscopic or Transthoracic Esophagectomy.

BACKGROUND/AIM: There is no study comparing open esophagectomy (OE), video-assisted thoracic surgery (VATS), and robot-assisted minimally invasive esophagectomy (RAMIE) in a single institution. PATIENTS AND METHODS: This study included 272 patients who underwent subtotal esophagectomy divided into three groups: OE (n=110), VATS (n=127), and RAMIE (n=35) groups. Moreover, short-term outcomes were compared. RESULTS: Overall complications (CD≥II) were significantly less in the RAMIE than the OE and VATS groups. Recurrent laryngeal nerve paralysis (CD≥II) was significantly lower in the RAMIE than the OE group (p=0.026) and tended to be lower than that in the VATS group (p=0.059). The RAMIE group had significantly less atelectasis (CD≥I and II), pleural effusion (CD≥I and II), arrhythmia (CD≥II), and dysphagia (CD≥II), than both the OE and VATS groups. CONCLUSION: RAMIE reduced overall postoperative complications after esophagectomy compared with both OE and VATS.

Nerve Injury During Ultrasound-Guided Thyroid Biopsy-A First Reported Complication of Permanent Vocal Fold Paralysis.

Needle biopsy is a well-established component in the evaluation of thyroid nodules. The biopsy is usually performed with an ultrasound guidance and consists of either fine-needle aspiration or core needle biopsy. Although these terms are often used interchangeably, their difference is important. To our knowledge, we discuss the first reported case of biopsy-proven laryngeal nerve injury and permanent vocal fold paralysis following ultrasound-guided core biopsy of the thyroid. We advocate this complication be discussed as part of the consent process.

Two trajectories of functional recovery in thyroid surgery related unilateral vocal cord paralysis.

BACKGROUND: Iatrogenic unilateral vocal fold paralysis caused by thyroid surgery induces profound physical and psychosocial distress in patients. The natural course of functional recovery over time differs substantially across subjects, but the mechanisms underlying this difference remain unclear. In this study, we examined whether the anatomic site of the lesion affected the trajectory of recovery. METHODS: In this prospective case series study in a single medical center, patients with thyroid surgery-related unilateral vocal fold paralysis were evaluated using quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, the Voice Outcome Survey, and the Short Form-36 quality-of-life questionnaire. Patients with and without superior laryngeal nerve injuries were compared. RESULTS: Forty-two patients were recruited, among whom 15 and 27 were assigned to the with and without superior laryngeal nerve injury groups, respectively. Compared with the group without superior laryngeal nerve injury, the group with superior laryngeal nerve injury group demonstrated less improvement in the recruitment of vocal fold adductors, and the group also had more severe impairment of vocal fold vibration, maximum phonation time, jitter, shimmer, and harmony-to-noise ratio at the first evaluation. This difference was also found in the glottal gap and maximum phonation time 12 months after the injury. CONCLUSION: Among patients with thyroid surgery-related unilateral vocal fold paralysis, superior laryngeal nerve injury induces a distinctively different recovery trajectory compared with those without superior laryngeal nerve injury characterized by less reinnervation of vocal fold adductors and worse presentation in terms of the glottal gap and maximum phonation time. This study emphasizes the importance of superior laryngeal nerve function and its preservation in thyroid surgery.

Superior Laryngeal Nerve Palsy in Revision Anterior Cervical Surgery.

Most spine surgeons routinely obtain preoperative ENT evaluation of recurrent laryngeal nerve function when contemplating revision anterior approaches to the cervical spine to avoid the potentially catastrophic consequences of bilateral vocal cord palsy. By contrast, there is less awareness of the potential for superior laryngeal nerve (SLN) injury-although a bilateral injury can, like bilateral injuries of the recurrent laryngeal nerve, have serious clinical consequences. This case report describes a 74-year-old man who, after a contralateral revision anterior approach to the upper cervical spine, developed bilateral SLN injury causing aspiration pneumonia and respiratory failure. We discuss risk factors associated with subclinical SLN injury and define at-risk patients who would benefit from preoperative SLN screening before revision anterior cervical surgery.

Impact of surgical volume and surgical outcome assessing registers on the quality of thyroid surgery.

The available evidence concerning the relationship between volume and outcome for thyroid surgery is assessed in this article. Morbidity forms the principal surrogate marker of thyroid surgery quality for which postoperative hypocalcaemia and recurrent laryngeal nerve injuries are most commonly reported upon. Whilst there is an abundance of published data for these outcomes, interpretation to recommend annual volume thresholds is challenging. This is due to a lack of consensus on definitions not only for outcomes but high and low volume surgeons. The evidence reviewed in this article supports the notion that high volume surgeons achieve superior outcomes in thyroid surgery quality though it is not possible to recommend minimal annual volumes on the basis of this evidence alone. Every thyroid surgeon should know their own outcomes and how they compare with their peers and engagement in thyroid surgery registries can facilitate this.

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.

Intraoperative Neurological Monitoring During Neck Dissection for Esophageal Cancer With Aberrant Subclavian Artery.

We report a case of esophageal cancer with a non-recurrent inferior laryngeal nerve associated with aberrant right subclavian artery that was treated by neck dissection using intraoperative neurological monitoring followed by thoracoscopic esophagectomy. A 76-year-old man had dysphagia. Endoscopy revealed thoracic esophageal cancer, and computed tomography revealed the presence of an aberrant right subclavian artery between the esophagus and vertebrae. We performed neck dissection followed by thoracoscopic esophagectomy. During the neck dissection, we confirmed a non-recurrent inferior laryngeal nerve through intraoperative neurological monitoring. No postoperative complications were observed, and the patient was discharged 19 days after surgery. We recommend using intraoperative neurological monitoring to avoid injury to the non-recurrent inferior laryngeal nerve associated with the aberrant right subclavian artery.

A critical review of thyroidectomy consent in the UK.

BACKGROUND: In 2015-16, the National Health Service (NHS) Litigation Authority received 10,965 claims for clinical negligence, with surgery having the highest number of claims. Currently a sum amounting to 25% of the annual NHS budget has been ring-fenced to meet extant claims. Claims made on a basis of inadequate informed consent are increasingly seen with many achieving a successful plaintiff outcome. There are presently no UK guidelines for thyroidectomy consent. METHOD: A prospective study was performed to investigate current consent practice among the British Association of Endocrine and Thyroid Surgeons (BAETS) membership and patients having previously undergone thyroidectomy. For surgeons, the Bolam legal test applied where surgeons declared what risks and complications they routinely consented for during their practice. A study was also undertaken in patients who had previously undergone thyroidectomy for cancer applying the rule of Montgomery. RESULTS: Consent practice from 193 surgeons and data from 415 patients was analysed. In total thyroidectomy for cancer, 95% of surgeons consent for Recurrent Laryngeal Nerve (RLN) injury and temporary or permanent voice change. 70% specifically consent for External Laryngeal Nerve (ELN) injury, 50% for tracheostomy and 55% for general anaesthetic associated complications. Analysis of patient data showed they would like to be consented for far more risks than they are presently informed about in general medical practice. There was significant variation in the consenting practice in BAETS surgeons. CONCLUSION: A BAETS approved consensus guideline to standardise UK consent practice would be appropriate. This may reduce complaints, litigation claims and guide expert witnesses.

Laryngeal and vocal alterations after thyroidectomy / Alterações laríngeas e vocais após tireoidectomia

Abstract Introduction: Dysphonia is a common symptom after thyroidectomy. Objective: To analyze the vocal symptoms, auditory-perceptual and acoustic vocal, videolaryngoscopy, the surgical procedures and histopathological findings in patients undergoing thyroidectomy. Methods: Prospective study. Patients submitted to thyroidectomy were evaluated as follows: anamnesis, laryngoscopy, and acoustic vocal assessments. Moments: pre-operative, 1st post (15 days), 2nd post (1 month), 3rd post (3 months), and 4th post (6 months). Results: Among the 151 patients (130 women; 21 men). Type of surgery: lobectomy + isthmectomy n = 40, total thyroidectomy n = 88, thyroidectomy + lymph node dissection n = 23. Vocal symptoms were reported by 42 patients in the 1st post (27.8%) decreasing to 7.2% after 6 months. In the acoustic analysis, f0 and APQ were decreased in women. Videolaryngoscopies showed that 144 patients (95.3%) had normal exams in the preoperative moment. Vocal fold palsies were diagnosed in 34 paralyzes at the 1st post, 32 recurrent laryngeal nerve (lobectomy + isthmectomy n = 6; total thyroidectomy n = 17; thyroidectomy + lymph node dissection n = 9) and 2 superior laryngeal nerve (lobectomy + isthmectomy n = 1; Total thyroidectomy + lymph node dissection n = 1). After 6 months, 10 patients persisted with paralysis of the recurrent laryngeal nerve (6.6%). Histopathology and correlation with vocal fold palsy: colloid nodular goiter (n = 76; palsy n = 13), thyroiditis (n = 8; palsy n = 0), and carcinoma (n = 67; palsy n = 21). Conclusion: Vocal symptoms, reported by 27.8% of the patients on the 1st post decreased to 7% in 6 months. In the acoustic analysis, f0 and APQ were decreased. Transient paralysis of the vocal folds secondary to recurrent and superior laryngeal nerve injury occurred in, respectively, 21% and 1.3% of the patients, decreasing to 6.6% and 0% after 6 months.

Resumo Introdução: A disfonia é um sintoma comum após a tireoidectomia. Objetivo: Analisar os sintomas vocais, auditivo-perceptivos e acústica vocal, videolaringoscopia, procedimento cirúrgico e achados histopatológicos em pacientes submetidos à tireoidectomia. Método: Estudo prospectivo. Pacientes submetidos à tireoidectomia foram avaliados da seguinte forma: anamnese, laringoscopia e avaliações vocais acústicas. Momentos: pré-operatório, 1ª avaliação pós (15 dias), 2ª avaliação pós (1 mês), 3ª avaliação pós (3 meses) e 4ª avaliação pós-operatória (6 meses). Resultados: Dos 151 pacientes, 130 eram mulheres e 21, homens. Tipos de cirurgia: lobectomia + istmectomia n = 40, tireoidectomia total n = 88, tireoidectomia + dissecção de linfonodo n = 23. Sintomas vocais foram relatados por 42 pacientes na 1ª avaliação pós-operatória (27,8%), reduzidos para 7,2% após 6 meses. Na análise acústica, f0 e APQ estavam diminuídos nas mulheres. As videolaringoscopias mostraram que 144 pacientes (95,3%) tiveram exames normais no momento pré-operatório. Paralisia das cordas vocais foi diagnosticada em 34 pacientes na 1ª avaliação pós-operatória, 32 do nervo laríngeo recorrente (lobectomia + istmectomia - n = 6; tireoidectomia total - n = 17; tireoidectomia total + dissecção de linfonodos - n = 9) e 2 do nervo laríngeo superior (lobectomia + istmectomia - n = 1; tireoidectomia total + dissecção de linfonodos - n = 1). Após 6 meses, 10 pacientes persistiram com paralisia do nervo laríngeo recorrente (6,6%). Histopatologia e correlação com paralisia das cordas vocais: bócio coloide nodular (n = 76; paralisia n = 13), tireoidite (n = 8; paralisia n = 0) e carcinoma (n = 67; paralisia n = 21). Conclusão: Os sintomas vocais, relatados por 27,8% dos pacientes na 1ª avaliação pós-operatória, diminuíram para 7% em 6 meses. Na análise acústica, f0 e APQ diminuíram. A paralisia transitória de cordas vocais secundária à lesão do nervo laríngeo recorrente e nervo laríngeo superior ocorreu, respectivamente, em 21% e 1,3% dos pacientes, reduziu-se para 6,6% e 0% após 6 meses.

Laryngeal and vocal alterations after thyroidectomy.

INTRODUCTION: Dysphonia is a common symptom after thyroidectomy. OBJECTIVE: To analyze the vocal symptoms, auditory-perceptual and acoustic vocal, videolaryngoscopy, the surgical procedures and histopathological findings in patients undergoing thyroidectomy. METHODS: Prospective study. Patients submitted to thyroidectomy were evaluated as follows: anamnesis, laryngoscopy, and acoustic vocal assessments. Moments: pre-operative, 1st post (15 days), 2nd post (1 month), 3rd post (3 months), and 4th post (6 months). RESULTS: Among the 151 patients (130 women; 21 men). Type of surgery: lobectomy+isthmectomy n=40, total thyroidectomy n=88, thyroidectomy+lymph node dissection n=23. Vocal symptoms were reported by 42 patients in the 1st post (27.8%) decreasing to 7.2% after 6 months. In the acoustic analysis, f0 and APQ were decreased in women. Videolaryngoscopies showed that 144 patients (95.3%) had normal exams in the preoperative moment. Vocal fold palsies were diagnosed in 34 paralyzes at the 1st post, 32 recurrent laryngeal nerve (lobectomy+isthmectomy n=6; total thyroidectomy n=17; thyroidectomy+lymph node dissection n=9) and 2 superior laryngeal nerve (lobectomy+isthmectomy n=1; Total thyroidectomy+lymph node dissection n=1). After 6 months, 10 patients persisted with paralysis of the recurrent laryngeal nerve (6.6%). Histopathology and correlation with vocal fold palsy: colloid nodular goiter (n=76; palsy n=13), thyroiditis (n=8; palsy n=0), and carcinoma (n=67; palsy n=21). CONCLUSION: Vocal symptoms, reported by 27.8% of the patients on the 1st post decreased to 7% in 6 months. In the acoustic analysis, f0 and APQ were decreased. Transient paralysis of the vocal folds secondary to recurrent and superior laryngeal nerve injury occurred in, respectively, 21% and 1.3% of the patients, decreasing to 6.6% and 0% after 6 months.

Risk factors for thyroid surgery-related unilateral vocal fold paralysis.

OBJECTIVES/HYPOTHESIS: We aimed to identify the risk factors for iatrogenic unilateral vocal fold paralysis (UVFP) caused by thyroid surgery, to allow the identification of patients requiring nerve-protection procedures and monitoring technologies. STUDY DESIGN: Retrospective case study in a medical center. METHODS: Patients who underwent thyroid surgery from April 2011 to February 2016 and who were diagnosed with UVFP by laryngoscopy and laryngeal electromyography were included. Patient demographics, types of surgery, and characteristics of the thyroid lesions were analyzed. RESULTS: Sixty (2.1%) of 2,815 patients who received thyroid surgery developed UVFP. The risk of UVFP was higher in patients over 60 years old (odds ratio, 1.89; 95% confidence interval, 1.01-3.26; P = .01). Involvement of the external branch of superior laryngeal nerve (EBSLN) occurred in 19 (31.7%) of the 60 UVFP patients, and was more likely to occurr in patients with diabetes mellitus (odds ratio, 14.19; 95% confidence interval, 3.80-52.94; P < .001). The incidence of UVFP and involvement of the EBSLN differed among surgery types, and was the highest among patients undergoing total thyroidectomy with neck dissection (TTND) (10/158, 6.3% and 5/158, 3.2%, respectively). CONCLUSIONS: The risk of thyroid surgery-related UVFP is higher in older patients. EBSLN involvement is more likely in patients with diabetes mellitus. TTND is associated with higher risks of UVFP and EBSLN injury than other types of surgery, implying the need of intraoperative nerve monitoring in these high-risk characteristics. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:275-283, 2019.

Ipsilateral nonrecurrent laryngeal nerve palsy and delayed palsy of the contralateral recurrent laryngeal nerve in a case of third-time reoperative thyroid surgery.

The occurrence of nonrecurrent laryngeal nerve and delayed nerve palsy of the contralateral nerve occurring simultaneously has never been described. A 67-year-old woman underwent reoperative completion thyroidectomy for enlarging thyroid nodules with recurrent hyperthyroidism and obstructive symptoms. Preoperative computed tomography of the neck showed a large compressive goitre with an aberrant right subclavian artery. At surgery, a type 1 nonrecurrent laryngeal nerve was found and inadvertently transected due to dense adhesions. It was repaired with ansa cervicalis graft. A fully preserved and functional recurrent laryngeal nerve was seen on the contralateral side at the end of surgery. However, the patient developed a delayed palsy on day 4 of the recurrent laryngeal nerve requiring a tracheostomy. Following successful speech and swallowing therapy, the patient was decannulated with good phonation and recovery of the left cord. Patients are at risk of bilateral nerve injury and late onset palsy in reoperative thyroid surgery. Management can be challenging and should be recognised to ensure appropriate therapy.

Non-Recurrent Laryngeal Nerve and Concurrent Vascular Variants: A Review.

OBJECTIVE: The purpose of this paper is to review the current data on the coexistence of non-recurrent laryngeal nerve (RLN) and vascular variations. METHODS: A systematic literature search was conducted on MEDLINE for case reports, original articles and reviews regarding the presence of non-RLN and coexisting vascular variants. RESULTS: From the literature search, 104 cases of non-RLN with confirmed vascular variants were reported. More specifically, 97.7% (n=101) of cases involved a right and 2.3% (n=3) a left non-RLN. The most common concurrent vascular variant reported with a right non-RLN was an aberrant right subclavian artery (97%; n=98). One case report (0.9%) of an intrathyroidal right common carotid artery was noted and 2 cases (1.9%) were associated with normal vascular anatomy. Furthermore, all 3 cases of a left non-RLN were associated with a right aortic arch, while 2 of them were also accompanied with situs inversus. CONCLUSIONS: The presence of vascular variations of the great vessels must prompt the surgeon to search for a non-RLN. Intraoperative neuromonitoring increases the detection rate of non-RLN. Further research is required to determine anatomic landmarks for the perioperative identification of a non-RLN, allowing its protection from potential injury.