Thyroid surgery during the COVID-19 pandemic: results from a systematic review.

PURPOSE: During the COVID-19 pandemic, elective thyroid surgery is experiencing delays. The problem is that the COVID-19 pandemic is ongoing. The research purposes were to systematically collect the literature data on the characteristics of those thyroid operations performed and to assess the safety/risks associated with thyroid surgery during the COVID-19 pandemic. METHODS: We used all the procedures consistent with the PRISMA guidelines. A comprehensive literature in MEDLINE (PubMed) and Scopus was made using ''Thyroid'' and "coronavirus" as search terms. RESULTS: Of a total of 293 articles identified, 9 studies met the inclusion criteria. The total number of patients undergoing thyroid surgery was 2217. The indication for surgery was malignancy in 1347 cases (60.8%). Screening protocols varied depending on hospital protocol and maximum levels of personal protection equipment were adopted. The hospital length of stay was 2-3 days. Total thyroidectomy was chosen for 1557 patients (1557/1868, 83.4%), of which 596 procedures (596/1558, 38.3%) were combined with lymph node dissections. Cross-infections were registered in 14 cases (14/721, 1.9%), of which three (3/721, 0.4%) with severe pulmonary complications of COVID-19. 377 patients (377/1868, 20.2%) had complications after surgery, of which 285 (285/377, 75.6%) hypoparathyroidism and 71 (71/377, 18.8%) recurrent laryngeal nerve injury. CONCLUSION: The risk of SARS-CoV-2 transmission after thyroid surgery is relatively low. Our study could promote the restart of planned thyroid surgery due to COVID-19. Future studies are warranted to obtain more solid data about the risk of complications after thyroid surgery during the COVID-19 era.

Association Between Subjective Voice Assessment and Psychological Distress After Thyroidectomy.

PURPOSE: This study aimed to determine the association between postoperative subjective voice function and psychological distress in patients without laryngeal nerve injury after thyroidectomy. DESIGN: A prospective cohort study. METHODS: We investigated the factors associated with subjective voice function in patients who underwent thyroidectomy without laryngeal nerve injury between October 2018 and July 2020. The Voice Handicap Index was used to assess subjective voice function, the GRBAS (grade, roughness, breathiness, asthenia, strain) scale to assess objective voice, and the Hospital Anxiety and Depression Scale to assess psychological distress. FINDINGS: Among 39 patients who underwent thyroidectomy, 32 had no postoperative laryngeal nerve injury. Postoperative Voice Handicap Index was significantly associated with Hospital Anxiety and Depression Scale-Anxiety score after surgery (rs = 0.448, P = .010). CONCLUSIONS: In this study, an association was observed between subjective voice function and anxiety following surgery. The finding suggested that nurses and medical practitioners need to consider postoperative anxiety when evaluating patients' voice function after thyroidectomy.

Uniqueness of laryngeal nerve injury following heart transplantation.

BACKGROUND: The incidence of recurrent laryngeal nerve injury (RLNI) after heart transplantation has not been well studied. This can manifest as vocal cord dysfunction causing dysphonia. Previous research is limited to aortic, coronary bypass, and valvular surgery. Identifying RLNI after heart transplantation is important in order to more accurately detail complications associated with this major surgery. METHODS: This is a retrospective study assessing 972 adult patients who underwent orthotopic heart transplantation between 2010-2019. Primary outcome was incidence of RLNI. Secondary outcomes were 1-year mortality and length of stay. Cardiology and otolaryngology notes were examined. Key word searches were used to identify possible RLNI in patients' health care record. RESULTS: 2.9% (29/972) of patients developed new RLNI confirmed by laryngoscopy during hospitalization. Patients with RLNI had a significantly increased risk of 1-year mortality (P = .015) and length of stay (P = .006) compared to those without RLNI. 68.9% (20/29) of RLNI was left-sided (68.9%). CONCLUSIONS: Recurrent laryngeal nerve injury is a recognizable adverse outcome following heart transplantation. This study supports that RLNI is associated with increased 1-year mortality and length of stay. Early otolaryngology evaluation may be warranted to evaluate vocal cord mobility and address potential management.

Cricopharyngeal myotomy for delayed Cricopharyngeal dysfunction after head and neck surgery - case report.

BACKGROUND: Head and neck surgeries can perturb normal structures of neck muscles and nerve innervations, which are supposed to function in harmony to allow complicated process like swallowing. It is still likely that cricopharyngal dysfunction emerges years after the head and neck surgeries. CASE PRESENTATION: We report a case with history of left unilateral vocal cord immobility and development of dysphagia and aspiration 2 years after radical thyroidectomy with neck lymph nodes dissection and medialization thyroplasty. Cricopharyngeal dysfunction was impressed and was confirmed with visualization of cricopharyngeal narrowing segment in radiographic contrast swallow examination. The patient was treated successfully by cricopharyngeal myotomy, achieving long-term relief in our 4 years of follow up. CONCLUSIONS: Our case of delayed cricopharyngal dysfunction after radical thyroidectomy and medialization thyroplasty shows that it is important to follow up swallowing functions after patients with UVCI undergo medialization thyroplasty. In the event of delayed manifestation of cricopharyngeal function, it can still be treated successfully by cricoharyngeal myotomy, achieving long term relief of dysphagia.

Patient Perception of Swallowing after Thyroidectomy in the Absence of Laryngeal Nerve Injury.

INTRODUCTION: Swallowing and voice alterations may manifest in patients with thyroid disease, especially after thyroidectomy. OBJECTIVE: To identify the prevalence of patients with complaints of swallowing disorders after thyroidectomy and to evaluate patients' perceptions regarding swallowing before and after the procedure. METHODS: A prospective longitudinal study was performed with 26 consecutive patients undergoing a private service thyroidectomy, in which the presence of swallowing dysfunction was evaluated using validated questionnaires that addressed the perception of swallowing by patients before (on the day of surgery) and after the surgery (on the first postoperative day). RESULTS: Of the 26 patients, 18 (69.2%) were subjected to total thyroidectomy and 8 to partial thyroidectomy. Analysis of the domains of the Swallowing Handicap Index questionnaire showed higher scores when evaluated on the first postoperative day, demonstrating a significant worsening in swallowing after the procedure. The same result was demonstrated for the final score of swallowing perception, with 15.3 and 30.8% of patients reporting moderate alterations before and after the thyroidectomy, respectively, and 11.5% reporting the alterations as severe. Swallowing and vocal symptoms on the first postoperative day were more prevalent in the procedure than previously mentioned. Eight patients (30.8%) noted swallowing alterations before the procedure, compared with 80.8% (21 cases) after thyroidectomy. CONCLUSION: There was a prevalence of 42.3% in swallowing complaints on the first postoperative day, regardless of the lesion in the laryngeal innervation, and this prevalence was significantly higher than that prior to the procedure.

Ex vivo investigation of the effect of the transverse arytenoid ligament on abduction of the arytenoid cartilage when performing equine laryngoplasty.

Aims: To investigate the effect of the transverse arytenoid ligament (TAL) on abduction of the arytenoid cartilage when performing laryngoplasty. Methods: Modified prosthetic laryngoplasty was performed on right and left sides of 13 cadaver larynges. Increasing force was sequentially applied to the left arytenoid cartilage at 3 N intervals from 0-24 N, when the force on the right arytenoid cartilage was either 0 or 24 N, before and after TAL transection. Digital photographs of the rostral aspect of the larynx were used to determine the left arytenoid abduction angles for these given force combinations and results compared before and after TAL transection. Longitudinal and transverse sections of the TAL from seven other equine larynges were also examined histologically. Results: Increasing force on the left arytenoid cartilage from 0-24 N produced a progressive increase in the angle of the left arytenoid cartilage (p < 0.001) and increasing force on the right arytenoid cartilage from 0-24 N reduced the angle of the left arytenoid cartilage (p < 0.001). Following transection of the TAL the mean angle of the left arytenoid increased from 36.7 (95% CI = 30.5-42.8)° to 38.4 (95% CI = 32.3-44.5)°. Histological examination showed that the TAL was not a discrete ligament between the arytenoid cartilages but was formed by the convergence of the ligament and the left and right arytenoideus transversus muscles. Conclusions: Transection of the TAL in ex vivo equine larynges enabled greater abduction of the left arytenoid cartilage for a given force. These results indicate that TAL transection in conjunction with prosthetic laryngoplasty may have value, but the efficacy and safety of TAL transection under load in vivo, and in horses clinically affected with recurrent laryngeal neuropathy must be evaluated. Abbreviations: Fmax: Force needed to maximally abduct the left or right arytenoid; TAL: Transverse arytenoid ligament.

Identification of loci affecting sexually dimorphic patterns for height and recurrent laryngeal neuropathy risk in American Belgian Draft Horses.

Equine recurrent laryngeal neuropathy (RLN) is a bilateral mononeuropathy with an unknown etiology. In Thoroughbreds (TB), we previously demonstrated that the haplotype association for height (LCORL/NCAPG locus on ECA3, which affects body size) and RLN was coincident. In the present study, we performed a genome-wide association scan (GWAS) for RLN in 458 American Belgian Draft Horses, a breed fixed for the LCORL/NCAPG risk alelle. In this breed, RLN risk is associated with sexually dimorphic differences in height, and we identified a novel locus contributing to height in a sex-specific manner: MYPN (ECA1). Yet this specific locus contributes little to RLN risk, suggesting that other growth traits correlated to height may underlie the correlation to this disease. Controlling for height, we identified a locus on ECA15 contributing to RLN risk specifically in males. These results suggest that loci with sex-specific gene expression play an important role in altering growth traits impacting RLN etiology, but not necessarily adult height. These newly identified genes are promising targets for novel preventative and treatment strategies.

Olfactory-ensheathing cells promote physiological repair of injured recurrent laryngeal nerves and functional recovery of glottises in dogs.

The aim of this study was to investigate whether the transplantation of olfactory-ensheathing cells (OECs) could physiologically repair severely injured recurrent laryngeal nerve (RLN) in dogs. Adult Beagle dogs were surgically introduced with a 10-mm defect in the left RLN and transplanted with a nerve guide (NEUROLAC) containing dog olfactory mucosa-olfactory-ensheathing cells (OM-OECs) in matrigel. The effects of OM-OECs on the morphology, histology, and electrophysiology of the injured RLNs, glottis movement, and voice acoustics were comparatively studied. Two months after transplantation, the normal dogs (group N) had intact left RLNs that contained axons well organized as bundles, transmitted action potentials of high amplitudes without latent phases, and modulated glottis movement to produce normal voices. The RLN-damaged dogs transplanted with OM-OECs (group CTT) had pieces of nerves regenerated in the place of the defects, which contained fewer axons scattered in the internal nerve membrane and wrapped peripherally by the connective tissue, prevented the distal trunk of the defected RLN from shrinking, transmitted action potentials of lower amplitudes with latent phases, and modulated a slightly impaired glottis movement to produce voices with slight differences compared to the N dogs. The RLN-damaged dogs without OM-OECs (group NC) had no nerves generated at the defective or the damaged area, leading to a shrinkage in the enervated distal nerve trunks; a blockage in nerve pulse transit; a paralysis of the left vocal cords; an impaired glottis movement; and abnormal voices. Transplantation of OM-OECs promoted nerve regeneration, and the recoveries of glottises and voices in dogs with RLN injury.

Surgical anatomy of the external branch of the superior laryngeal nerve: a systematic review and meta-analysis.

PURPOSE: To provide a comprehensive evidence-based assessment of the anatomical characteristics of the external branch of the superior laryngeal nerve (EBSLN). MATERIALS AND METHODS: A thorough systematic search was performed on the major electronic databases PubMed, EMBASE, Cochrane library, and ScienceDirect to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcomes were the EBSLN identification rate (total number of EBSLN identified divided by the total number of dissected hemilarynges) and the prevalence of various EBSLN types. RESULTS: A total of 56 studies (n = 13,444 hemilarynges) were included. The overall pooled EBSLN identification rate was 89.24% (95% CI 85.49-92.49). This rate was higher for cadaveric (95.00%; 95% CI 89.73-99.35) compared to that reported in intraoperative studies (86.99%; 95% CI 82.37-91.01). Significantly higher identification rates were reported for studies in which intraoperative nerve monitoring was used (95.90%; 95% CI 94.30-97.25) compared to those which only relied on direct visual identification of the EBSLN (76.56%; 95% CI 69.34-83.08). Overall, Cernea type IIa (nerves crossing the superior thyroid artery less than 1 cm above the upper edge of the superior thyroid pole) and Friedman type 1 (nerves running their entire course superficial to the inferior pharyngeal constrictor) were the most prevalent (41.84%; 95% CI 33.28-48.08 and 50%; 95% CI 29.90-65.62, respectively). The combined prevalence of Cernea IIa and IIb (nerves crossing the superior thyroid artery below the upper edge of the superior thyroid pole) was higher in intraoperative studies compared to that in cadaveric studies (64.3% vs 49.4%). The EBSLN coursed medial to the superior thyroid artery in 70.98% (95% CI 55.14-84.68) of all cases. CONCLUSION: The use of intraoperative nerve monitoring improves EBSLN identification rates. In light of the highly variable anatomical patterns displayed by the EBSLN, thorough pre-operative knowledge of its anatomy can be crucial in minimizing incidences of its iatrogenic injury.

Two-Stage Indicators to Assess Learning Curves for Minimally Invasive Ivor Lewis Esophagectomy.

BACKGROUND: Minimally invasive esophagectomy (MIE) Ivor Lewis has been increasingly performed over the last two decades. To guide the implementation of this technically demanding procedure, a comprehensive assessment of MIE-Ivor Lewis learning curves should include both the general competence to accomplish the procedure and the ability to generate oncological benefits. These objectives are believed to be associated with different phases of the learning curve. METHODS: A retrospective review of the first 109 patients who underwent MIE-Ivor Lewis by a single qualified surgeon was conducted. Relevant variables were collected and assessed by regression analysis to identify suitable indicators for patient stratification and learning curve assessment. Thereafter, the differential analysis was performed among groups to validate the learning curve model. RESULTS: Two variables, intrathoracic gastroesophageal anastomosis time and bilateral recurrent laryngeal nerve (RLN) lymphadenectomy number, which plateaued, respectively, after the 26th and 88th cases, were selected as meaningful indicators to identify different competence levels. Therefore, 109 patients were chronologically subcategorized into three groups (the first 26 MIEs as the early group, the next 62 cases as the middle group, and 21 most recent cases as the late group). Perioperative data were compared between groups with positive results to indicate a three-phase model for a learning curve for MIE-Ivor Lewis. CONCLUSIONS: An MIE-Ivor Lewis learning curve should include three discrete phases that indicate, successively, unskilled operation (general competence to accomplish, less proficiency), surgical proficiency, and oncological efficacy. Intrathoracic anastomosis time and bilateral RLN lymphadenectomy were identified as suitable indicators delineate the different stages of an MIE-Ivor Lewis learning curve.

LVC Timing in Infant Pig Swallowing and the Effect of Safe Swallowing.

Recurrent laryngeal nerve (RLN) injury in neonates, a complication of head and neck surgeries, leads to increased aspiration risk and swallowing dysfunction. The severity of resulting sequelae range from morbidity, such as aspiration pneumonia, to mortality from infection and failure to thrive. The timing of airway protective events including laryngeal vestibule closure (LVC) is implicated in aspiration. We unilaterally transected the RLN in an infant pig model to observe changes in the timing of swallowing kinematics with lesion and aspiration. We recorded swallows using high-speed video-fluoroscopic swallow studies (VFSS) and scored them using the Infant Mammalian Penetration and Aspiration Scale (IMPAS). We hypothesized that changes would occur in swallowing kinematics (1) between RLN lesion and control animals, and (2) among safe swallows (IMPAS 1), penetration swallows (IMPAS 3), and aspiration swallows (IMPAS 7). We observed numerous changes in timing following RLN lesion in safe and unsafe swallows, suggesting pervasive changes in the coordination of oropharyngeal function. The timing of LVC, posterior tongue, and hyoid movements differed between pre- and post-lesion in safe swallows. Posterior tongue kinematics differed for post-lesion swallows with penetration. The timing and duration of LVC and posterior tongue movement differed between aspiration swallows pre- and post-lesion. After lesion, safe swallows and swallows with aspiration differed in timing of LVC, laryngeal vestibule opening, and posterior tongue and hyoid movements. The timing of thyrohyoid muscle activity varied with IMPAS, but not lesion. Further study into the pathophysiology of RLN lesion-induced swallowing dysfunction is important to developing novel therapies.

Clinical effect of total thyroidectomy combined with radioactive iodine in thyroid cancer treatment.

Aim of this research work is to observe and analyze the clinical effect of total thyroidectomy combined with radioactive iodine in thyroid cancer treatment. The 120 thyroid cancer patients treated in our hospital were enrolled as study subjects and assigned to study group (treated with total thyroidectomy and radioactive iodine) and reference group (treated with conventional total thyroidectomy). The overall treatment efficacy was compared between the two groups. Comparison of overall treatment efficacy of the two groups showed that the study group has superior results to the reference group (P<0.05). Comparison of incidence of recurrent laryngeal nerve injury in the two groups revealed no significant differences, P>0.05. However, in life quality assessment, the study group was significantly superior to the reference group in terms of physiological function, psychological function, social function, and overall life quality scores, P<0.05. Total thyroidectomy combined with radioactive iodine can well improve the overall treatment efficiency and enable patients to have higher quality of life at the same time.

An update on the status of nerve monitoring for thyroid/parathyroid surgery.

PURPOSE OF REVIEW: Recurrent laryngeal nerve (RLN) injury is one of the most common and serious complications associated with thyroid and parathyroid surgery. Although routine visual identification of the RLN is considered the current standard of care, the role of intraoperative neuromonitoring (IONM) of the RLN is more controversial. RECENT FINDINGS: Despite initial enthusiasm that IONM might substantially reduce the rate of RLN injury, most studies failed to show a significant difference in the rate of RLN injury when the use of IONM was compared with visualization of the RLN alone. However, a small number of investigators have reported statistically significant differences in the rates of nerve injury when IONM is used to augment visualization alone, particularly in certain high-risk situations. Despite a lack of conclusive data showing benefit, the use of IONM as an adjunct to visual identification of the RLN has gained increasing acceptance among surgeons. IONM remains an excellent tool to help verify the identity of the RLN, confirm its functional integrity, and pinpoint the site of nerve injury in the event of dysfunction. SUMMARY: The utility of IONM in reducing the rate of RLN injury is largely unproven and remains controversial. However, the use of IONM may be helpful in certain high-risk cases. Promising new technology, such as vagal nerve monitoring, may allow more real-time monitoring of the functional integrity of the RLN and allow the surgeon to react in a timely manner to evolving dysfunction in order to abort maneuvers that may risk definitive injury.

The Identification, Preservation and Classification of the External Branch of the Superior Laryngeal Nerve in Thyroidectomy.

BACKGROUND: Avoiding injury to the external branch of the superior laryngeal nerve is one of the major challenges during thyroid operation. The aim of this study was to propose a practical classification of the external branch of the superior laryngeal nerve. METHODS: A retrospective study of total thyroidectomy was performed. Totally 240 patients were included, with 480 external branches of the superior laryngeal nerves explored by intraoperative neuromonitoring. The classification of the external branch of the superior laryngeal nerve was determined by the distance between the upper edge of the superior thyroid pole and the lowest point of the nerve when the thyroid lobe was retracted in the lateral and inferior direction. Multinomial logistic regression analysis was run to predict the type of the nerve from several variables. RESULTS: The identification rate of the external branch of the superior laryngeal nerve was 98.54% (473 of 480 nerves). Higher ratio of longitudinal size of the thyroid lobe to ipsilateral neck length increased the likelihood of that both the type 2 and 3 nerve with respect to type 1 nerve, with OR 2.72, 95% CI = 1.21-6.12 and OR 5.30, 95% CI = 2.09-13.44, respectively. (1a) The nerve whose lowest point (entry into the muscle) was located more than 1 cm above the horizontal plane passing the upper border of superior thyroid pole. (1b) The nerve whose lowest point (the point right above the superior thyroid pole) was located more than 1 cm above the plane. (2a) The nerve whose lowest point (entry into the muscle) was located within 1 cm above the plane. (2b) The nerve whose lowest point (the point right above the superior thyroid pole) was located within 1 cm above the plane. (3a) The nerve whose lowest point (entry into the muscle) was located below the plane. (3b) The nerve whose lowest point (the point right below the superior thyroid pole) was located anterior to the gland. (3c) The nerve whose lowest point (the point right below the superior thyroid pole) was located posterior to the gland. CONCLUSIONS: Identification rate of the external branch of the superior laryngeal nerve by intraoperative neuromonitoring was significantly high. Understanding the new practical classification of the nerve allows for better identification and function preservation of this nerve during thyroidectomy.

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.

Unilateral Laryngeal Pacing System and Its Functional Evaluation.

Goal. To establish a reliable instrumental system for synchronized reactivation of a unilaterally paralyzed vocal fold and evaluate its functional feasibility. Methods. Unilateral vocal fold paralysis model was induced by destruction of the left recurrent laryngeal nerve (RLN) in anesthetized dogs. With a micro controller-based electronic system, electromyography (EMG) signals from cricothyroid (CT) muscle on the ipsilateral side were recorded and used to trigger pacing of paralyzed vocalis muscles. The dynamic movement of vocal folds was continuously monitored using an endoscope, and the opening and closing of the glottis were quantified with customized imaging processing software. Results. The recorded video images showed that left side vocal fold was obviously paralyzed after destructing the RLN. Using the pacing system with feedback triggering EMG signals from the ipsilateral CT muscle, the paralyzed vocal fold was successfully reactivated, and its movement was shown to be synchronized with the healthy side. Significance. The developed unilateral laryngeal pacing system triggered by EMG from the ipsilateral side CT muscle could be successfully used in unilateral vocal fold paralysis with the advantage of avoiding disturbance to the healthy side muscles.

Pre-pharyngeal Swallow Effects of Recurrent Laryngeal Nerve Lesion on Bolus Shape and Airway Protection in an Infant Pig Model.

Recurrent laryngeal nerve (RLN) damage in infants leads to increased dysphagia and aspiration pneumonia. Recent work has shown that intraoral transport and swallow kinematics change following RLN lesion, suggesting potential changes in bolus formation prior to the swallow. In this study, we used geometric morphometrics to understand the effect of bolus shape on penetration and aspiration in infants with and without RLN lesion. We hypothesized (1) that geometric bolus properties are related to airway protection outcomes and (2) that in infants with RLN lesion, the relationship between geometric bolus properties and dysphagia is changed. In five infant pigs, dysphagia in 188 swallows was assessed using the Infant Mammalian Penetration-Aspiration Scale (IMPAS). Using images from high-speed VFSS, bolus shape, bolus area, and tongue outline were quantified digitally. Bolus shape was analyzed using elliptical Fourier analysis, and tongue outline using polynomial curve fitting. Despite large inter-individual differences, significant within individual effects of bolus shape and bolus area on airway protection exist. The relationship between penetration-aspiration score and both bolus area and shape changed post lesion. Tongue shape differed between pre- and post-lesion swallows, and between swallows with different IMPAS scores. Bolus shape and area affect airway protection outcomes. RLN lesion changes that relationship, indicating that proper bolus formation and control by the tongue require intact laryngeal sensation. The impact of RLN lesion on dysphagia is pervasive.

Laryngeal electromyographic changes in postthyroidectomy patients with normal vocal cord mobility.

Thyroidectomy has been used for the treatment of thyroid disease for more than 100 years. In spite of the advancement of surgical techniques, there is still a risk of laryngeal nerve injury. The risk of partial or complete injury still depends on some surgical and disease-related factors. The aim of this study is to show the partial injury and to establish these risk factors via laryngeal electromyographic analysis (LEMG) in postthyroidectomy patients with normal vocal cord motion and mucosal anatomy. Patients who had undergone thyroid surgery were enrolled in this prospective study. LEMG analysis was performed to all patients with normal vocal cord mobility preoperatively and was repeated after the first and the third months of surgery. Thyroarytenoid (TA) and cricothyroid (CT) muscles were used to evaluate recurrent and external branch of superior laryngeal nerves, respectively. Four of the 32 patients had mild-to-moderate degrees of partial LEMG changes during preoperative LEMG analysis of TA and CT muscles on each side. After 3 months of surgery, there was a statistically significant worsening of LEMG findings in the right and left external branches of superior and left recurrent laryngeal nerves. Disease and surgery-related risk factors were analyzed. However, there was no significant relationship on the progression of LEMG findings according to these parameters. This is the first prospective study which supports the risk of progression of LEMG changes in patients with normal laryngoscopic examination after thyroid surgery. No reliable significant risk factor was found influencing the LEMG progression.

[The possibilities for the restoration of the laryngeal function: the current state-of-the-art]. / Vozmozhnosti vosstanovleniia funktsii gortani: sovremennyi podkhod.

The restoration of the functional competence of the larynx following bilateral laryngeal nerve damage and vocal fold paralysis is a serious challenge for the surgeon that has thus far no satisfactory solution. Physiological re-innervation that occurs naturally with time is non-selective and, in the majority of the cases, leads to synkinesis. Laryngeal pacing achieved with the application of the implantable microchips appears to be a promising approach. The animal experiments have demonstrated the possibility of successful restoration of all the functions of the larynx by means of laryngeal pacing but simultaneously revealed a number of technical issues that have to be addressed if the further progress in this field is to be achieved including the choice of the proper materials for implantation, solution of problems pertaining to the neuromuscular mapping during pacer implantation, etc.). The results of the first prospective clinical trial involving the human patients gave evidence suggesting that the laryngeal electrostimulation technology is both safe and efficient. Nevertheless, further investigations and modification of the method are needed before it can be recommended for the wider application in the routine clinical practice.

Carotid endarterectomy significantly improves postoperative laryngeal sensitivity.

OBJECTIVE: Iatrogenic injury of the vagus nerve or its branches during carotid endarterectomy (CEA) can result in globus sensation, dysphagia, and even vocal fold immobility. Knowledge of morphologic and functional laryngopharyngeal outcomes after CEA is poor. The present study was performed to determine potential iatrogenic damage to the laryngeal innervation after CEA. An area of particular interest was the supraglottic sensory threshold, which was examined by Fiberoptic Endoscopic Evaluation of Swallowing With Sensory Testing (FEESST; Pentax Medical Company, Montvale, NJ), a validated and safe method for the determination of the motor and sensory components of swallowing. METHODS: FEESST was used preoperatively in 32 patients scheduled to undergo CEA and twice postoperatively to examine the motor and sensory components of swallowing. In this endolaryngeal examination, laryngopharyngeal sensory thresholds (in mm Hg) were defined as normal at <4.0 mm Hg air pulse pressure (APP), moderate deficit at 4.0 to 6.0 mm Hg APP, or severe deficit at >6.0 mm Hg APP, with a value >10.0 mm Hg APP indicating abolished laryngeal adductor reflex. Acoustic voice parameters were also analyzed for further functional changes of the larynx. RESULTS: The mean ± standard deviation preoperative FEESST measures showed no significant differences (P = .065) between the operated-on side (6.73 ± 1.73 mm Hg) and the opposite side (5.83 ± 1.68 mm Hg). At 2 days postoperatively, the threshold increased (P = .001) to 7.62 ± 1.98 mm Hg on the operated-on side. A laryngopharyngeal mucosal hematoma on the operated side was endoscopically detectable in eight patients (30.8%); in these patients, we found a markedly elevated (P = .021) measure of 9.50 ± 0.93 mm Hg. On the opposite (nonoperated-on) side of the laryngopharynx, the thresholds remained at the same level as preoperatively over all assessments (P >.05), whereas the differences between the operated and nonoperated-on sides and the hematoma and nonhematoma groups were highly significant (P = .004 and P = .001, respectively). Surprisingly, the sensory threshold on the operated-on side (6.08 ± 2.02 mm Hg) decreased significantly at the 6-week follow-up, even in relation to the preoperative measure (P = .022). With the exception of one patient with permanent unilateral vocal fold immobility, no signs of nerve injury were detected. CONCLUSIONS: In accordance with previous reports, injuries to the recurrent laryngeal nerve during CEA seem to be rare. In most patients, postoperative symptoms (globus, dysphagia, dysphonia) and signs fade within a few weeks without any specific therapeutic intervention. This study shows an improved long-term postoperative superior laryngeal nerve function with regard to laryngopharyngeal sensitivity.