Recurrent laryngeal nerve injury after thyroidectomy: A national study from Saudi Arabia.

OBJECTIVES: To determine the incidence and possible risk factors of recurrent laryngeal nerve injury, to provide a relevant literature review of studies from other centers in Saudi Arabia, and to present basic statistical data for future studies in our local community. METHODS: A retrospective study enrolled patients who were surgically treated for thyroid disease between January 2015 and December 2021. For concerns during the procedure, direct laryngoscopy was carried out before extubation to assess the vocal cords. Similarly, indirect laryngoscopy was carried out for patients who developed postoperative voice changes. All patients were evaluated clinically 2-3 weeks after surgery. Nerve monitors were not used in either case. RESULTS: The study examined 437 participants: 361 (82.6%) female and 76 (17.4%) male individuals. The incidence of recurrent laryngeal nerve injury was 1.1%. The demographic characteristics, pathology (benign vs. malignant), and extent of thyroidectomy were not significantly associated with the risk of recurrent laryngeal nerve injury. CONCLUSION: A recurrent laryngeal nerve injury is a serious complication, and further studies are required to determine the safest techniques for thyroidectomy. However, centralization of thyroid surgery in high-volume centers might reduce this risk.

The Causes and Laryngeal Electromyography Characteristics of Unilateral Vocal Fold Paralysis.

OBJECTIVE: To investigate the causes and laryngeal electromyography (LEMG) characteristics of unilateral vocal fold paralysis (UVFP). METHODS: We retrospectively analyzed the history and LEMG of 337 patients with unilateral vocal fold immobility. The etiology was reviewed and the characteristics of LEMG (including spontaneous potential, recruitment potential, evoked potential, synkinesia, and et al.) were analyzed. RESULTS: The causes included injury (177 cases, 52.5%), idiopathic causes (72 cases, 21.4%), infection (61 cases, 18.1%), tumor and compressive factors (27 cases, 8.0%). Among the injury group, 161 cases were caused by surgery (111 cases of thyroid surgery), and 16 cases were caused by trauma. LEMG showed that complete nerve injury was present in 72.9% of the injury group, 66.7% of the tumors or compressive factors group, 49.2% of the infection group, and 44.4% of the idiopathic group. Of the 337 patients, 136 patients (40.4%) had synkinesia in the posterior cricoarytenoid muscles, and only two of these patients also had synkinesia in the thyroarytenoid muscles. The proportion of complete recurrent laryngeal nerve (RLN) injury in patients with synkinesia was higher than that of patients without synkinesia. CONCLUSION: The main cause of vocal fold paralysis is neck surgery, most commonly thyroid surgery. Patients with different causes of paralysis had different severities of RLN injury. LEMG showed that surgery or trauma accounted for the highest proportion of complete nerve injury. Patients with severe RLN injury were more prone to synkinesia, and the posterior cricoarytenoid muscles were more likely to have synkinesia than the thyroarytenoid muscles.

The incidence of recurrent laryngeal nerve injury resulting in vocal cord paralysis following interventional congenital catheterisation procedures.

BACKGROUND: Recurrent laryngeal nerve injury leading to vocal cord paralysis is a known complication of cardiothoracic surgery. Its occurrence during interventional catheterisation procedures has been documented in case reports, but there have been no studies to determine an incidence. OBJECTIVE: To establish the incidence of left recurrent laryngeal nerve injury leading to vocal cord paralysis after left pulmonary artery stenting, patent ductus arteriosus device closure and the combination of the procedures either consecutively or simultaneously. METHODS: Members of the Congenital Cardiovascular Interventional Study Consortium were asked to perform a retrospective analysis to identify cases of recurrent laryngeal nerve injury after the aforementioned procedures. Twelve institutions participated in the analysis. They also contributed the total number of each procedure performed at their respective institutions for statistical purposes. RESULTS: Of the 1337 patients who underwent left pulmonary artery stent placement, six patients (0.45%) had confirmed vocal cord paralysis. 4001 patients underwent patent ductus arteriosus device closure, and two patients (0.05%) developed left vocal cord paralysis. Patients who underwent both left pulmonary artery stent placement and patent ductus arteriosus device closure had the highest incidence of vocal cord paralysis which occurred in 4 of the 26 patients (15.4%). Overall, 92% of affected patients in our study population had resolution of symptoms. CONCLUSION: Recurrent laryngeal nerve injury is a rare complication of left pulmonary artery stent placement or patent ductus arteriosus device closure. However, the incidence is highest in patients undergoing both procedures either consecutively or simultaneously. Additional research is necessary to determine contributing factors that might reduce the risk of recurrent laryngeal nerve injury.

Human Amnion/Chorion Membrane May Reduce Transient Recurrent Laryngeal Nerve Injury During Thyroid Surgery.

Recurrent laryngeal nerve (RLN) damage is a significant and prevalent complication of thyroid surgery. Based on the beneficial role of a human amnion/chorion membrane (HACM) allograft in wound management and nerve regeneration, we investigated whether placement of a commercially available HACM allograft on dissected RLN could reduce the occurrence and/or duration of RLN injury during thyroidectomy. Among 67 patients undergoing thyroidectomy, 100 at-risk nerves (exposure of at least 3 cm of RLN) received intraoperative placement of HACM; 205 at-risk RLNs without HACM in 134 matched patients served as controls. Patient-reported vocal analysis, physician-assessed vocal analysis, and laryngoscopic assessment of vocal-fold dysfunction were performed before and after surgery. At 24 h after surgery, 17 patients in the control group (12.5%) had documented voice changes; these changes persisted for at least 3 weeks in seven patients (5%). Only one patient (1.5%) in the HACM group had vocal changes at 24 h after surgery, which resolved within 1 week (P < 0.01). Intraoperative placement of the HACM allograft over at-risk RLNs during thyroidectomy may reduce the incidence, severity, and/or duration of intraoperative RLN injury, which could address a significant complication of head and neck surgery. A larger prospectively designed clinical study is warranted to further investigate a possible benefit of the HACM allograft in thyroid surgery and to begin to understand the mechanisms through which a clinical benefit might be mediated.

Recurrent Laryngeal Nerve Paralysis Following Thyroidectomy: Analysis of Factors Affecting Nerve Recovery.

OBJECTIVES: Paralysis of the recurrent laryngeal nerves (RLNs), albeit decreased over the years, leaves the surgeon helpless as there is not much that can be done once it occurs. Nimodipine has been suggested as a remedy that could accelerate the recovery of the nerve. Our study aimed to examine the factors that affect the recovery rate (RR) and time to recovery (TTR) of post-thyroidectomy RLN paralysis, with an emphasis on the use of nimodipine. METHODS: A total of 197 patients who had undergone thyroid and parathyroid surgeries were retrospectively reviewed from October 2016 to August 2019. Patients who had RLN paralysis following surgery were assessed. The medical records were retrospectively analyzed to look for possible factors that may influence RLN recovery. RESULTS: A total of 289 nerves were at risk. Temporary RLN paralysis rate was 7.9% while 1.7% was permanent. Age (odds ratio [OR] = 4.8) and intra-operative extra-thyroid extension (OR = 9.0) were independent risk factors for RLN paralysis. The rate of recovery was 82.1%. Loss of signal (LOS; P = .066) was a factor trending for an impact on RR but not nimodipine (P > .05). The mean TTR was 32 days. LOS, nimodipine, and steroid use, among others, were factors trending for an impact on the TTR. CONCLUSION: Although not reaching statistical significance, nimodipine and steroids might influence TTR but not the RR. Larger studies are warranted to address the effect of nimodipine on the outcome of RLN paralysis. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1692-1696, 2022.

Application of intraoperative nerve monitoring for recurrent laryngeal nerves in minimally invasive McKeown esophagectomy.

BACKGROUND: Mediastinal lymphadenectomy is of great importance during esophagectomy for esophageal squamous cell carcinoma. However, recurrent laryngeal nerve (RLN) injury is a severe complication caused by lymphadenectomy along the RLN. Intraoperative nerve monitoring (IONM) can effectively identify the RLN and reduce the incidence of postoperative vocal cord paralysis (VCP). Here, we describe the feasibility and effectiveness of IONM in minimally invasive McKeown esophagectomy. METHODS: A total of 150 patients who underwent minimally invasive McKeown esophagectomy from 2016 to 2020 were enrolled in this study. We divided the patients into two groups: a neuromonitoring group (IONM, n = 70) and a control group (control, n = 80). Clinical data, surgical variables, and postoperative complications were retrospectively analyzed and compared. RESULTS: There was no significant difference in baseline data between the two groups. Postoperative VCP occurred in six cases (8.6%) in the IONM group, which was lower than that in the control group (21.3%, P = 0.032). Postoperative pulmonary complications were found in five cases (7.1%) and 14 in the control group (18.8%, P = 0.037). The postoperative hospital stay in the IONM group was significantly shorter than that in the control group (8 vs. 12, median, P < 0.001). The number of RLN lymph nodes harvested in the IONM group was higher than that in the control group (13.74 ± 5.77 vs. 11.03 ± 5.78, P = 0.005). The sensitivity and specificity of IONM monitoring VCP were 83.8% and 100%, respectively. A total of 66.7% of patients with a reduction in signal showed transient VCP, whereas 100% with a loss of signal showed permanent VCP. CONCLUSION: IONM is feasible in minimally invasive McKeown esophagectomy. It showed advantages for distinguishing RLN and achieving thorough mediastinal lymphadenectomy with less RLN injury. Abnormal IONM signals can provide an accurate prediction of postoperative VCP incidence.

How blue lining the recurrent laryngeal nerve can aid in re-operative surgery?

The recurrent laryngeal nerve (RLN), is one of the main structures at risk of injury causing vocal cord paralysis during head and neck surgery, especially during thyroid or parathyroid surgery, central neck dissection and upper oesophageal sphincter surgery. We describe the systematic use of marking of the RLN using non-resorbable blue polypropylene suture after its localisation, just inside its penetration below the cricopharyngeal muscle, to help identify the nerve for cases of re-operative surgery in this area. This specific marking technique could facilitate subsequent preservation of the nerve and reduce nerve injury risk in cases of planned or unexpected future operations, as well as emergency surgery due to postoperative complications. We apply this technique simultaneously with intra-operative laryngeal neuromonitoring. This method is safe and easy to perform.

The Effect of Energy Devices, Nerve Monitors, and Drains on Thyroidectomy Outcomes: An American College of Surgeons National Surgical Quality Improvement Project Database Analysis.

The effect of energy devices, nerve monitors, and drains on thyroidectomy outcomes has been examined for each tool independently. Current literature supports the routine use of energy devices and nerve monitors and does not support the routine use of drains. The effect of these operative tools is interrelated and should be examined concurrently. The aim of this study was to describe the risk-adjusted effect of each of these tools on thyroidectomy outcomes. A retrospective analysis of 17 985 open thyroidectomy procedures was conducted using the American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) 2016-2018 thyroidectomy targeted procedure database. All open thyroidectomies were included. The risk-adjusted effect of energy devices, nerve monitors, and drains on 30-day outcomes was calculated by multiple logistic regression. Energy devices were associated with a decreased risk of hematoma and decreased extended length of stay without increased risk of hypocalcemia or recurrent laryngeal nerve injury. Nerve monitors were associated with a decreased risk of overall morbidity, decreased recurrent laryngeal nerve injury, and decreased extended length of stay without an increased risk of adverse outcomes. Drains were associated with an increased risk of bleeding, reoperation, and extended length of stay without decreasing hematoma. Our results support the routine use of energy devices and nerve monitors for thyroidectomy and do not support the routine use of drains for thyroidectomy.

MRI Study of Jellyfish Collagen, Hyaluronic Acid, and Cadaveric Dermis for Injection Laryngoplasty.

OBJECTIVES/HYPOTHESIS: Test a new jellyfish collagen biomaterial aimed to increase duration of injection medialization laryngoplasty (IL) against two products in clinical practice. STUDY DESIGN: Animal model. METHODS: Left recurrent laryngeal nerve sectioning and IL were performed in New Zealand White rabbits (N = 6/group). Group 1 received micronized cross-linked jellyfish collagen (MX-JC) and adipose derived stem cells (ADSCs), Group 2, MX-JC alone, Group 3, cross-linked hyaluronic acid (X-HA), and Group 4, micronized acellular dermis (MACD). Animals were sacrificed at 4 and 12 weeks. Major outcomes were MRI tissue volumes and histopathology. RESULTS: After 100 µL IL MRI volumes (means ± STD) at 4 and 12 weeks were: Group 1: 27.2 ± 15.6 and 13.1 ± 5.2 µL, Group 2: 60.8 ± 18 and 27.8 ± 2.47 µL, Group 3: 27.4 ± 12 and 10.6 ± 8 µL, and Group 4: 37.5 ± 11 and 9.85 ± 1 µL. Group 2 volumes were largest and Group 3 were smallest in all comparisons (P < .05). Histologically, low grade inflammatory responses were observed in Group 1, mild histiocytic infiltration in Group 2, widespread muscle fiber loss in Group 3, and plasmocytic infiltration in Group 4. CONCLUSIONS: MX-JC showed the least resorption at 4 and 12 weeks among all groups. T cell inflammatory responses were observed with MX-JC but were reduced by 12 weeks while B cell immune responses, indicative of antibody priming, were predominantly noted with MACD. MX-JC + ADSC showed low grade immunity while the XHA showed greater myocyte loss compared to the other groups. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E2452-E2460, 2021.

Characteristics of Early Internal Laryngeal Muscle Atrophy After Recurrent Laryngeal Nerve Injuries in Rats.

OBJECTIVES/HYPOTHESIS: The present study investigated the characteristics of early internal laryngeal muscle atrophy in recurrent laryngeal nerve injury (RLNI) rats. STUDY DESIGN: To observe the characteristics of early internal laryngeal muscle atrophy post RLNI. METHODS: Rats were divided into three groups: sham-operated control group (n = 20), recurrent laryngeal nerve transverse injury group (RLNTI, n = 50), and recurrent laryngeal nerve blunt contusion group (RLNBC, n = 50). Five weeks after RLNI, certain rats were sacrificed weekly, and their laryngeal tissues were harvested. The atrophic features of internal laryngeal muscles were detected using hematoxylin and eosin. NF-κB and MuRF-1 levels were tested using IHC. RESULTS: The atrophic degree and fibrosis of thyroarytenoid, posterior cricoarytenoid, and lateral cricoarytenoid muscles were related to the type of RLNI. The average myofiber cross-sectional areas increased before an obvious decrease in the RLNTI and RLNBC groups. Muscle recovery occurred in the RLNBC group starting 4 weeks after RLNI, but only a weak trend was observed in the RLNTI group in the 5th week. During the muscle atrophy process, MuRF-1 and NF-κB were upregulated early and were maintained at a high level, which showed a trend similar to muscle atrophy. However, NF-κB expression was opposite to MuRF-1 expression and muscle atrophy when the muscles recovered. CONCLUSION: The atrophy degree of internal laryngeal muscles was associated with the type of RLNI. The NF-κB/MuRF-1 signaling pathway was involved in internal laryngeal muscle atrophy after RLNI, which is different from skeletal muscle after denervation. LEVEL OF EVIDENCE: NA Laryngoscope, 131:E1256-E1264, 2021.

Rehabilitation Protocol for Unilateral Laryngeal and Lingual Paralysis (Tapia Syndrome): Comment About "A Challenging Case of Tapia Syndrome After Total Thyroidectomy" By Ildem Deveci, Mehmet Surmeli, and Reyhan Surmeli.

Tapia syndrome is a rare complication after surgery, with ipsilateral paralysis of vocal cord and tongue due to extracranial involvement of recurrent laryngeal and hypoglossal nerves. Tapia's case report is extremely interesting for both the rarity of the reported cases and for the importance of an early rehabilitation. In a previous work, we reported a case of Tapia syndrome after cardiac surgery for aortic aneurysm, and the protocol of logopedic rehabilitation adopted. In the postoperative period, he developed severe dyspnea and dysphagia that required a tracheostomy and a logopedic rehabilitation therapy that led to a fast and efficient swallowing without aspiration after 47 sessions (less than 4 months). The progressive recovery of the function suggests aprassic nerve damage. However, the logopedic therapy is recommended to limit the possibility of permanent functional deficits and quickly recover swallowing and phonation.

PCA Atrophy and Synkinesis as the Main Factors for Persistent Vocal Fold Immobility in RLN Paralysis.

OBJECTIVES/HYPOTHESIS: An immobile vocal fold due to recurrent laryngeal nerve (RLN) injury usually shows no gross signs of atrophy and lies near the midline. In 1881, Felix Semon proposed that this phenomenon was due to a selective injury of nerve fibers supplying the posterior cricoarytenoid muscle (PCA) and supported this with postmortem proof of selective PCA atrophy. In recent decades, evidence has emerged that the RLN regenerates after injury but does not always result in useful motion of the vocal folds. It has been proposed that this is caused by laryngeal synkinesis. Laryngeal synkinesis describes a random distribution of regenerated nerve fibers to opposing vocal fold muscles. This study was conducted to clarify the relative contribution of these two potential pathomechanisms in our patient population. STUDY DESIGN: Retrospective case analysis. METHODS: Retrospective analysis of laryngeal EMG results from cases with RLN paralysis of at least 6 months duration seen at our neurolaryngology clinic. RESULTS: Out of 118 PCA EMGs, there was not a single normal or near-normal tracing, whilst 33.3% of TA EMGs indicated normal or near normal innervation. PCA EMGs showed signs of persistent high-grade partial denervation (41.5%) as a sign of atrophy, moderate or strong synkinesis (21.2%), or a combination of both (37.3%). CONCLUSIONS: In chronic RLN paralysis the intrinsic laryngeal muscles are affected to different extents either by atrophy or synkinesis or a combination of both. The PCA is always affected. The lesser damage to TA innervation explains the commonly seen maintenance of vocal fold muscle bulk. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1244-E1248, 2021.

A Surgical Mouse Model for Advancing Laryngeal Nerve Regeneration Strategies.

Iatrogenic recurrent laryngeal nerve (RLN) injury is a morbid complication of anterior neck surgical procedures. Existing treatments are predominantly symptomatic, ranging from behavioral therapy to a variety of surgical approaches. Though laryngeal reinnervation strategies often provide muscle tone to the paralyzed vocal fold (VF), which may improve outcomes, there is no clinical intervention that reliably restores true physiologic VF movement. Moreover, existing interventions neglect the full cascade of molecular events that affect the entire neuromuscular pathway after RLN injury, including the intrinsic laryngeal muscles, synaptic connections within the central nervous system, and laryngeal nerve anastomoses. Systematic investigations of this pathway are essential to develop better RLN regenerative strategies. Our aim was to develop a translational mouse model for this purpose, which will permit longitudinal investigations of the pathophysiology of iatrogenic RLN injury and potential therapeutic interventions. C57BL/6J mice were divided into four surgical transection groups (unilateral RLN, n = 10; bilateral RLN, n = 2; unilateral SLN, n = 10; bilateral SLN, n = 10) and a sham surgical group (n = 10). Miniaturized transoral laryngoscopy was used to assess VF mobility over time, and swallowing was assessed using serial videofluoroscopy. Histological assays were conducted 3 months post-surgery for anatomical investigation of the larynx and laryngeal nerves. Eight additional mice underwent unilateral RLN crush injury, half of which received intraoperative vagal nerve stimulation (iVNS). These 8 mice underwent weekly transoral laryngoscopy to investigate VF recovery patterns. Unilateral RLN injury resulted in chronic VF immobility but only acute dysphagia. Bilateral RLN injury caused intraoperative asphyxiation and death. VF mobility was unaffected by SLN transection (unilateral or bilateral), and dysphagia (transient) was evident only after bilateral SLN transection. The sham surgery group retained normal VF mobility and swallow function. Mice that underwent RLN crush injury and iVNS treatment demonstrated accelerated and improved VF recovery. We successfully developed a mouse model of iatrogenic RLN injury with impaired VF mobility and swallowing function that can serve as a clinically relevant platform to develop translational neuroregenerative strategies for RLN injury.

Recurrent laryngeal nerve transection in mice results in translational upper airway dysfunction.

The recurrent laryngeal nerve (RLN) is responsible for normal vocal-fold (VF) movement, and is at risk for iatrogenic injury during anterior neck surgical procedures in human patients. Injury, resulting in VF paralysis, may contribute to subsequent swallowing, voice, and respiratory dysfunction. Unfortunately, treatment for RLN injury does little to restore physiologic function of the VFs. Thus, we sought to create a mouse model with translational functional outcomes to further investigate RLN regeneration and potential therapeutic interventions. To do so, we performed ventral neck surgery in 21 C57BL/6J male mice, divided into two groups: Unilateral RLN Transection (n = 11) and Sham Injury (n = 10). Mice underwent behavioral assays to determine upper airway function at multiple time points prior to and following surgery. Transoral endoscopy, videofluoroscopy, ultrasonic vocalizations, and whole-body plethysmography were used to assess VF motion, swallow function, vocal function, and respiratory function, respectively. Affected outcome metrics, such as VF motion correlation, intervocalization interval, and peak inspiratory flow were identified to increase the translational potential of this model. Additionally, immunohistochemistry was used to investigate neuronal cell death in the nucleus ambiguus. Results revealed that RLN transection created ipsilateral VF paralysis that did not recover by 13 weeks postsurgery. Furthermore, there was evidence of significant vocal and respiratory dysfunction in the RLN transection group, but not the sham injury group. No significant differences in swallow function or neuronal cell death were found between the two groups. In conclusion, our mouse model of RLN injury provides several novel functional outcome measures to increase the translational potential of findings in preclinical animal studies. We will use this model and behavioral assays to assess various treatment options in future studies.

Transition from video-assisted thoracoscopic to robotic esophagectomy: a single surgeon's experience.

Lymph node dissection (LND) along the left recurrent laryngeal nerve (RLN) is a technically challenging part of esophageal cancer surgery, especially after chemoradiotherapy (CRT). Robotic surgery holds promise to increase its safety and feasibility. The aim of this study was to describe a single thoracoscopic surgeon's experience related to the transition from video-assisted esophagectomy (VATE) to robotic esophagectomy (RE)-with a special focus on the safety of left RLN LND. Patients who underwent minimally invasive esophagectomy and RLN dissection following CRT were dichotomized according to the use of robotic surgery (robotic esophagectomy [RE] versus video-assisted thoracoscopic esophagectomy [VATE]). The following parameters were determined: (1) number of dissected nodes, (2) rates of RLN palsy, (3) rates of perioperative complications, and (4) learning curve. Learning curve analysis was performed using the 10-patient moving average (MA) for operation times and with the cumulative sum (CUSUM) method for left RLN LND (target failure rate: 15%). The RE and VATE groups consisted of 39 and 67 patients, respectively. The intraoperative identification of the left RLN was more common in the RE group (97.4%) than in the VATE group (68.7%; P < 0.001). Postoperative left RLN palsy was significantly more frequent in the VATE group (26.9%) than in the RE group (10.3%; P = 0.042), with a higher rate of pneumonia in the former (16.4% versus 2.6%; P = 0.03). The MA chart revealed a downward trend followed by a flattening of the RE operation time at operation number 17 and 29, respectively. CUSUM analysis showed that the left RLN palsy rate decreased to the target rate after 12 operations. We conclude that at least 12 cases are required for a surgeon with prior experience in VATE to safely accomplish left RLN LND through a robotic approach.

Morphometric Differences in the Recurrent Laryngeal Nerve in Patients with Vocal Fold Paralysis.

OBJECTIVES: Injury to the recurrent laryngeal nerve (RLN), if severe enough, can result in vocal fold paralysis. Reinnervation surgery can improve patient outcomes, but previous studies have reported a negative correlation between time since onset of paralysis and surgical outcomes. The ability of the paralyzed nerve to serve as a conduit for donor nerve fibers may be a factor in the success of reinnervation; however, changes in RLN composition after paralysis have not been well studied. Therefore, we investigated the morphometric composition of explanted RLN sections from patients who had experienced vocal fold paralysis for varying length of times. METHODS: Nine nerve sections from unilateral vocal fold paralysis (UVP) patients and seven control nerve sections were analyzed for morphometric parameters including fascicular area, fiber count, fiber density, fiber packing, mean g-ratio, and fiber diameter distribution. Nerves from UVP patients were also compared as a function of time since UVP onset. RESULTS: In comparison to control nerves, paralyzed nerves were found to have significantly lower fiber densities and fiber packing, higher mean g-ratio values, and a shift in diameter distributions toward smaller diameter fibers. With respect to paralysis duration, no significant differences were observed except in fiber diameter distributions, where those with paralysis for >2 years had distributions that were significantly shifted toward smaller diameter fibers. CONCLUSIONS: The morphometric data presented here suggest that correlations between the time since onset of vocal fold paralysis and reinnervation outcomes may be due to fiber size changes in the paralyzed nerve over time.

Unilateral Vocal Fold Immobility After Prolonged Endotracheal Intubation.

Importance: Endotracheal intubation and mechanical ventilation are life-saving treatments for acute respiratory failure but are complicated by significant rates of dyspnea and dysphonia after extubation. Unilateral vocal fold immobility (UVFI) after extubation can alter respiration and phonation, but its incidence, risk factors, and pathophysiology remain unclear. Objectives: To determine the incidence of UVFI after prolonged (>12 hours) mechanical ventilation in a medical intensive care unit and investigate associated clinical risk factors for UVFI after prolonged mechanical ventilation. Design, Setting, and Participants: This subgroup analysis of a prospective cohort study was conducted in a single-center medical intensive care unit from August 17, 2017, through May 31, 2018, among 100 consecutive adult patients who were intubated for more than 12 hours. Patients were identified within 36 hours of extubation and recruited for study enrollment. Those with an established tracheostomy prior to mechanical ventilation, known laryngeal or tracheal pathologic characteristics, or a history of head and neck radiotherapy were excluded. Exposure: Invasive mechanical ventilation via an endotracheal tube. Main Outcomes and Measures: The incidence of UVFI as determined by flexible nasolaryngoscopy. Results: One hundred patients (62 men [62%]; median age, 58.5 years [range, 19.0-87.0 years]) underwent endoscopic evaluation after extubation. Seven patients had UVFI, of which 6 cases (86%) were left sided. Patients with hypotension while intubated (odds ratio [OR], 10.8; 95% CI, 1.6 to ∞), patients requiring vasopressors while intubated (OR, 16.7; 95% CI, 2.4 to ∞), and patients with a preadmission diagnosis of peripheral vascular disease (OR, 6.2; 95% CI, 1.2-31.9) or coronary artery disease (OR, 5.1; 95% CI, 1.0-25.5) were more likely to develop UVFI. Conclusions and Relevance: Unilateral vocal fold immobility occurred in 7 of 100 patients in the medical intensive care unit who were intubated for more than 12 hours. Unilateral vocal fold immobility was associated with inpatient hypotension and preadmission vascular disease, suggesting that ischemia of the recurrent laryngeal nerve may play a role in disease pathogenesis.

Unilateral Vocal Fold Immobility in Children.

Unilateral vocal fold paralysis (UVFP) in children may cause dysfunction in voice, swallowing, and breathing, thus influencing all components of laryngeal function. UVFP in children is usually the result of iatrogenic injury. The approach to patients with suspected UVFP should involve a detailed patient history, a focused physical examination with flexible nasopharyngoscopy, and relevant imaging if the cause of UVFP is uncertain. Management aims to strengthen voice, decrease aspiration, and improve quality of life. Laryngeal reinnervation is becoming more common, potentially offering permanent improvement in vocal and swallowing function through increasing bulk and tone to the paralyzed vocal fold.

Isolated Recovery of Adductor Muscle Function Following Bilateral Recurrent Laryngeal Nerve Injuries.

OBJECTIVES/HYPOTHESIS: The aim of this study was to analyze the phoniatric and respiratory outcomes of a subset of bilateral vocal cord paralysis (BVCP) patients who were all treated with unilateral endoscopic arytenoid abduction lateropexy (EAAL). EAAL is a nondestructive, minimally invasive glottis widening operation, which does not damage either the surgically treated or the contralateral vocal cord. Therefore, it does not impair the regeneration potential of the recurrent laryngeal nerve. STUDY DESIGN: Case series. METHODS: Ten out of 21 BVCP patients who were treated with EAAL showed signs of isolated adduction recovery at 1 year and were chosen for this study. Functional results (objective and subjective voice analysis, spirometric measurement) and vocal cord movements were assessed preoperatively, 1 week and 1 year after EAAL. Laryngeal electromyography was performed on the 12th postoperative month. RESULTS: The volitional adductor movement seen on laryngoscopy was corroborated by laryngeal electromyography evaluation. Peak inspiratory flow increased significantly after EAAL. Quality-of-life scores also showed high patient satisfaction. Shimmer showed consistent improvement along with harmonic-to-noise ratio and average maximal phonation time in parallel with the improving vocal cord movement. Complex voice analysis and subjective self-evaluation tests also demonstrated significant improvement. CONCLUSIONS: EAAL, as a minimally invasive, nondestructive airway widening technique, does not interfere with the potential regeneration process that can still occur after BVCP, allowing for laryngeal functional recovery. It is a safe and effective treatment for BVCP that allows a simple solution with good phonatory, swallowing, and respiratory benefits by unilateral passive and reversible vocal cord lateralization. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:2334-2340, 2019.

Incidence and Treatment Outcomes of Vocal Fold Movement Impairment After Total Arch Replacement.

BACKGROUND: Vocal fold movement impairment (VFMI) secondary to neuronal injury is a known risk after aortic surgery. Total arch replacement is technically challenging, and the incidence of vocal fold movement impairment secondary to neuronal injury after this surgery is unknown. This study examined the incidence of VFMI after total arch replacement and medialization treatment outcomes. STUDY DESIGN: Retrospective cohort study. METHODS: All patients who underwent total arch replacement at a tertiary care center over 11 years (2006-2017) were identified through an institutional database. End points included evidence of VFMI on flexible laryngoscopy, time to diagnosis, time to treatment, need for reintubation, and intensive care unit (ICU) and hospital length of stay. RESULTS: Of the 358 patients who underwent total arch replacement, 63 (20%) were diagnosed with VFMI during their initial inpatient stay. Fifty patients (79%) VFMIs were left-sided, nine (14%) were right-sided, and four (6%) were bilateral. Thirty-nine patients (62%) underwent inpatient vocal fold medialization: 28 (72%) by injection laryngoplasty and 11 (28%) by type 1 thyroplasty. Those with unilateral VFMI had longer ICU (8.9 days) and hospital (19.4 days) than those with no VFMI (5.7 and 16.1 days). Among patients with unilateral VFMI, those who underwent inpatient vocal fold medialization trended toward shorter ICU (6.2 vs. 14.4 days, P = .03) and hospital stays (20.1 vs. 23.3 days, P = .4) than patients who did not have a medialization procedure. CONCLUSION: The overall incidence of VFMI after total arch replacement in our series was 20%. Both the right and left vocal folds are potentially at risk from a total arch replacement; consequently, the distribution of injury in our cohort was more heterogeneous than in other series. LEVEL OF EVIDENCE: 3 Laryngoscope, 129:699-703, 2019.