Vocal Fold Research Articles

453. ROBOT ESOPHAGECTOMY WITH EXTENDED MEDIASTINAL LYMPH NODE DISSECTION FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Radical surgical resection may play role in prognosis improvement of the esophageal squamous cell carcinoma (ESCC) patients. Because esophagectomy with radical lymphadenectomy is highly invasive, we introduced thoracoscopic esophagectomy in 1999, and have performed over 600 cases. In 2009, we developed a hybrid of the prone and left lateral decubitus positions for thoracoscopic esophagectomy with extended LN dissection and reported good long-term outcomes especially in cT1bN0M0 ESCC patients. We reported 3y and 5y RFS was 96% and 96%, and 3y and 5y OS was 94% and 92% in those patients. We introduced robot-assisted esophagectomy (RMIE) using daVinci Xi system in June 2018 and have performed for 80 cases. We perform RMIE with the prone position instead of the hybrid position with same concept of thoracoscopic esophagectomy with extended LN dissection. Thanks to a three-dimensional magnified view, fully wristed dexterity and tremor filtration of da Vinci Xi system, the robotic system facilitates precise dissection especial for upper mediastinal lymph node dissection. We show safety introduction and technical pitfalls of robot-assisted esophagectomy with extended LN dissection. Methods: The patient is fixed on prone position. We use Monopolar curved scissors for superficial layer, bipolar cut for dissection with maryland bipolar forceps for deeper layer around Aorta and trachea, and Sharp dissection with Potts scissors around recurrent laryngeal nerves. After esophageal mobilization and mediastinal lymphadenectomy were completed, bilateral recurrent laryngeal nerve, bilateral subclavian artery, trachea, bilateral bronchus, aorta, left pulmonary artery and vein, left pleura, pericardium and hiatus are all skeletonized. Results: We could standardize surgical procedure in first 20 cases. Average operation time in the thoracic procedure is 234.4min and 190.2min in last 30 cases. Median blood loss is 0ml. Postoperative pneumonia and vocal cord palsy were occurred only 6 case in 80 cases. Conclusion: Robot assisted esophagectomy with extended LN dissection was safely introduced in our facility and it is feasible and beneficial for the lymph node dissection especially for lymph node dissection around the recurrent laryngeal nerve. https://www.dropbox.com/scl/fi/w8na39w6bo9ivwwz7x2rh/Hirofumi-Kawakubo-ISDE-2024.mp4?rlkey=p9mvt7dotyeaj6xfwvud8vcmr&dl=0

Value of radiofrequency ablation for treating locally recurrent thyroid cancer: a systematic review and meta-analysis for 2-year follow-up.

To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating locoregional recurrent thyroid cancer (LRTC) after a 2-year follow-up time. PubMed, Embase and Cochrane Library were searched from inception until 20 September 2022 to find studies reporting the safety and efficacy of RFA in LRTC patients after a 2-year follow-up. Two radiologists performed the data extraction and methodological quality assessment according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We analyzed 6 studies, 229 LRTC patients with 319 locally recurrent tumors were treated with RFA. The mean follow-up time of each study was ≥24 months. The pooled changes in the largest diameter and volume were 7.22 mm (95% confidence interval (CI), 6.35-8.09 mm) and 164.28 mm3 (95% CI, 87.78-240.77 mm3), respectively; the pooled volume reduction rate was 95.03% (95% CI, 87.56-102.49%). The total complete disappearance rate after treatment was 92% (95% CI, 83-100%). The pooled decrease of serum thyroglobulin levels was 0.02 ng/ml (95% CI, -0.00-0.04 ng/ml). The pooled proportion of recurrence rate was 6% (95% CI, 0-13%). The pooled complication rate was 5% (95% CI, 0-10%). The major complications were voice change and hoarseness, only one patient developed permanent vocal cord paralysis; minor complications were cough and pain. Ultrasound-guided RFA is an effective and safe treatment for LRTC based on 2-year follow-up results.

510. INNOVATIVE ROBOTIC-ASSISTED ESOPHAGECTOMY WITH THREE-FIELD LYMPHADENECTOMY: A NOVEL APPROACH TO ESOPHAGEAL CANCER SURGERY

Abstract Background Esophageal squamous cell carcinoma, the predominant form of esophageal cancer in Thailand, often presents at advanced stages (III - IV), necessitating surgical intervention. Radical esophagectomy, including three-field lymphadenectomy, stands as one of the most invasive gastrointestinal surgeries. However, in the era of minimally invasive surgery (MIS), robotic systems have emerged as a formidable approach to achieve radical treatment goals while minimizing surgical invasiveness. This video showcases a novel surgical technique and its challenges. Methods A case of mid-thoracic esophageal squamous cell carcinoma, clinically staged III, treated via robotic-assisted esophagectomy and three-field lymphadenectomy using the Da Vinci Xi system. The operation encompassed three phases: Initially, the thoracic phase with patient in semi-prone position with three robotic and one assistant trocars for complete esophageal mobilization and mediastinal lymph node retrieval. The abdominal phase, followed by the cervical phase, utilized four robotic trocars and one assistant trocar in supine position with hyperextended neck, facilitating perigastric lymph node retrieval, gastric tube reconstruction via the posterior mediastinal route, and cervical esophago-gastric tube anastomosis using a circular stapler. Results The patient experienced an uneventful recovery. Postoperative esophagogastroduodenoscopy on day 1 revealed the integrity of the anastomosis and normal vocal cord function. Imaging conducted on day 7 confirmed that the anastomosis was patent without any leakage. Surgical outcomes included an operative time of 615 minutes, estimated blood loss of 150 ml, a 14-day hospital stay, and recovery without complications. This video highlights the intricacies of the procedure and the robotic system's ability to access anatomically challenging spaces, thereby minimizing surgical invasiveness and enhancing recovery. Conclusion The robotic system is capable of performing radical procedures in anatomically challenging areas, such as narrow spaces and areas requiring precise maneuverability among vital structures. It enables a comprehensive approach spanning from the upper to the lower thoracic regions and diversity of surgery in thoracic and abdominal cavity. Additionally, this presentation highlights unique surgical tips and techniques that enhance the safety and feasibility of robotic-assisted esophagectomy. By significantly reducing surgical errors and optimizing outcomes for both oncologic and minimally invasive surgeries, it thereby marks a significant leap forward in the field of esophageal surgery. https://drive.google.com/file/d/1vrmu2D8TGoetnplcREPWQocXJle4PrOX/view?usp=share_link

246. EFFECT OF INTRAOPERATIVE NERVE MONITORING DURING MINIMALLY INVASIVE ESOPHAGECTOMY

Abstract Background Recurrent laryngeal nerve (RLN) lymphadenectomy is a crucial step during esophagectomy. However, it is technically demanding and associated with a significant risk of RLN injury. Despite several studies demonstrating the feasibility of intraoperative nerve monitoring (IONM) during esophageal surgery, routine utilization of IONM during minimally invasive esophagectomy has not become common, and there is limited evidence to provide robust guidance. Here, we describe our experience with IONM during minimally invasive McKeown esophagectomy. Methods Data from 115 consecutive patients who underwent bilateral RLN lymphadenectomy during thoracoscopic McKeown esophagectomy for esophageal squamous cell carcinoma (ESCC) by a single surgeon between July 2017 and November 2023 were reviewed. The cohort was divided into three groups: Group 1 (initial 23 cases without IONM), Group 2 (middle 46 cases without IONM), and Group 3 (late 46 cases with IONM). We compared the number of resected lymph nodes and the incidence of vocal cord palsy (VCP) among the three groups. Results The mean number of resected right-side RLN lymph nodes was 1.21, 2.30, and 3.28 in Groups 1, 2, and 3, respectively. A significant difference was noted between Groups 2 and 3 (p = 0.03, Kruskal-Wallis test). The mean number of resected left-side RLN lymph nodes was 1.13, 2.70, and 2.67 in Groups 1, 2, and 3, respectively. A significant difference was noted between Groups 1 and 2 (p = 0.009), but not between Groups 2 and 3. The incidence of VCP was 8.7%, 8.7%, and 10.9% in Groups 1, 2, and 3, respectively. Compared to Group 2, the utilization of IONM in Group 3 did not reduce the postoperative VCP rate (OR: 1.280, 95% CI: 0.321-5.107). Conclusions With increasing experience, the number of resected RLN lymph nodes significantly increased. However, the utilization of IONM did not further improve left-side RLN lymphadenectomy or reduce the VCP rate.

Upper airway manifestations of anti-IgLON5 disease: Otorhinolaryngological point of view

IntroductionAnti-IgLON5 disease is a recently described neurological disorder with multisystemic features. The disease is characterized by the presence of IgLON5 antibodies in serum and cerebrospinal fluid. Our objective is to describe in detail the otorhinolaryngological manifestations of this disease, which are frequent and may include dysphagia, dysarthria, vocal cord paralysis and laryngospasm. MethodsIn this study, we present a series of 9 patients with anti-IgLON5 disease and otolaryngological manifestations. Patients were evaluated between July 2012 and March 2022 by video-polysomnography, fiber-optic laryngoscopy, and functional endoscopic evaluation of swallowing. ResultsThe median age was 71 years, and 5 (56%) were female. Video-polysomnography showed a NREM/REM parasomnia in 6 patients (67%), obstructive sleep apnea in 8 (88%), stridor during sleep in 7 (78%) and central apneas in 1 (11%). Six out of the 9 patients (67%) presented episodes of acute respiratory failure that required mechanical ventilation, 6 had vocal fold palsy with 4 of them requiring tracheostomy (3 had to be performed on an emergency basis). Dysphagia occurred in 8 patients (89%). Prominent upper airway secretion and sialorrhea was also present in 3 cases. ConclusionThe anti-IgLON5 disease exhibits extensive otolaryngological symptoms, mainly affecting the upper airway. These symptoms affect the quality of life and can be life-threatening. Prompt acute management is essential for stridor, dyspnea, and dysphagia. Given the potential severity of the symptoms and rarity of the disease, it is important for otolaryngologists to be familiar with anti-IgLON5 disease. Level of evidenceLevel 4.

552. COMPARING ROBOTIC ESOPHAGECTOMY TO VIDEO-ASSISTED THORACOSCOPIC ESOPHAGECTOMY FOR ESOPHAGEAL SQUAMOUS CELL CARCINOMA: RESULTS FROM THE REVATE RANDOMIZED CLINICAL TRIAL

Abstract Background The treatment of esophageal squamous cell carcinoma (ESCC) includes dissecting lymph nodes along the recurrent laryngeal nerve (RLN), which is oncologically important but is technical demanding. Vocal cord palsy as a result from RLN injury, carries significant morbidities. This randomized clinical trial (RCT) compared the efficacy and safety of robotic esophagectomy (RE) and video-assisted thoracoscopic esophagectomy (VATE) for performing RLN lymph node dissection (LND) Methods We conducted a multicenter RCT(NCT03713749) from November 2018 to March 2022, enrolling patients with ESCC who required McKeown esophagectomy. The primary endpoint was to determine the success rate of left RLN LND. Success was defined as the removal of lymph nodes confirmed by pathology, without causing permanent nerve palsy (duration > 6 months). Secondary endpoints encompassed perioperative and oncological outcomes. Results The per-protocol analysis included data from 203 patients (RE group: n=103; VATE group: n=100). The primary endpoint was achieved in 88.3% of the RE group and 69% of the VATE group (p<0.001). Additionally, the RE group had a higher mediastinal lymph node harvest (16 [12−22] versus 14 [10−20], p=0.04), shorter thoracic operating time (110 [89−137] min versus 124[103.5−154] min, p=0.004), and earlier drainage removal (4 [3−7] days versus 6 [4−9] days, p=0.007) compared to the VATE group. The two study arms exhibited comparable complication rates with no recorded in-hospital deaths in either group. Conclusion This multicenter trial demonstrates the effectiveness of RE in enhancing the feasibility and safety of RLN LND in ESCC. Additionally, RE leads to an improved mediastinal lymphadenectomy, shorter operating times, and earlier removal of drainage.

Laryngeal Reinnervation as a Treatment Option for Permanent Unilateral Vocal Fold Paralysis

Laryngeal Reinnervation as a Treatment Option for Permanent Unilateral Vocal Fold Paralysis

Comparing Pre-Post Outcomes of Laryngeal Microsurgery With Voice Therapy for Patients With Vocal Fold Polyps

Comparing Pre-Post Outcomes of Laryngeal Microsurgery With Voice Therapy for Patients With Vocal Fold Polyps

Impact of the in-office surgical activity on the classical phonomicrosurgical interventions in a laryngology referral center.

Office-based laryngology procedures evolved in the recent years with all the technology advances and have gained popularity among laryngologists. The indications enlarged, making it a valid surgical option for almost all voice disorders. This emerging technique raise the question of the place left for traditional phonosurgeries in the operating room under general anesthesia. We reviewed our surgical activity in our laryngology referral center from 2018 to 2023. Since we started the in-office procedures in 2018, the number of these interventions significantly increased, accompanying a significant increase in our total surgical activity. We noted no significant decrease in the number of interventions done in the operating room, which made us consider the office-based procedures as a complimentary and not a competitive option for traditional surgeries, helping us increase our total number of interventions, and thus offer patients more opportunities for a quicker medical care. Our register review showed also a change of treatment trends for unilateral vocal fold paralysis, with office-based interventions becoming the first-line treatment.

Highly sensitive flexible pressure sensor based on laser ablated Ag-MWCNT /MXene for human motion detection

The complex and dynamic human environment, higher requirements are put forward for the high-performance flexible pressure sensors. The materials selection and microstructure design are crucial to achieve high sensitivity and stability. In this work, we fabricated pressure sensitive layer with multiple dimensional materials. Using laser ablation in liquid method, Ag nanoparticles were uniformly distributed in surface of multi-walled carbon nanotubes (MWCNT). Combined with the delaminated MXene, highly pressure sensitive composite could be prepared due to the reduction of contact resistance under pressure. The corresponding piezoresistive sensors showed high sensitivity (12.7 kPa−1), excellent response speed (150 ms), recovery speed (100 ms), and distinguished cycle stability (3000 cycles). Based on the performance of the sensor, it can realize the monitoring of tiny pressure on the human body, and further realize the detection of human activities and health. In addition, the sensor array has spatial recognition capability, providing a way of thinking for the development needs of future intelligent wearable electronic devices. The sensors can measure changes in resistance caused by finger bending, slight breathing, pulse, vocal cord vibration, and other movements to realize human activity and health monitoring. At the same time, the 3×3 sensor array system can recognize the layout of pressure in space. This simple preparation and low cost of the sensor can Facilitate the progress towards sophisticated wearable electronic gadgets.

Synchronous 3D Imaging of the Medial and Superior Vocal Fold Surface in an excised human Hemilarynx.

This study investigates relationships between the oscillation behavior of the medial and superior vocal fold (VF) surfaces during sustained phonation in a human cadaver hemilarynx. An experimental test stand synchronously captured the medial and superior VF surfaces of a human ex vivo hemilarynx during sustained phonation using two high-speed camera setups in 24 experimental settings. The 3D coordinates of the medial VF surface were reconstructed by triangulation of sewn-in marker points, while laser-based reconstruction was used for the superior VF surface. Correlation analysis and linear regression were used to quantify the connections of the mean and maximal vertical and lateral VF displacements and the VF velocities. Additionally, stepwise linear regression was used to analyze the impact of the measurement variables mean flow rate, adduction and elongation. Strong linear relationships between all of the tested corresponding parameter pairs of the superior and medial VF surfaces were found (p<.001). Mean and maximum vertical displacements of the medial surface were both approximately 50% of the superior surface. The mean lateral displacements for the medial surface were 12% below the superior surface but 12% higher for the maximum values. The mean and maximum VF velocities were 32% and 36% lower for the medial surface. The suggested multi-modal test stand allows efficient, comprehensive analysis of human hemilarynges and provides promising information about the interaction of the different VF areas and opens up the systematic analysis of multiple hemilarynges. In future, our results could integrate into ENT diagnostics using 3D laryngoscopy where the hidden medial VF surface dynamics may be predicted from the observable superior surface.

Mucosal Injection of the Silicon Phthalocyanine Pc 4 in a Rabbit Model-A Pilot Study.

The silicon phthalocyanine Pc 4 is a photosensitizing agent previously shown to be a promising treatment for cutaneous neoplasms using photodynamic therapy (PDT). Based on prior preclinical studies, we believe Pc 4-PDT has potential as a targeted treatment of human recurrent respiratory papillomatosis or laryngeal leukoplakia by direct injection into mucosal surfaces. This was a proof-of-concept pilot study assessing direct mucosal injection of Pc 4 into buccal and vocal fold mucosae in a rabbit model. Five New Zealand white rabbits underwent tattooing of bilateral buccal mucosae to delineate injection sites, followed by submucosal injections of control and Pc 4 solutions. Rabbits were monitored for post-injection tolerance. Punch biopsies were obtained from injected mucosa and assessed histopathologically. Once the buccal mucosa was found to be tolerant, vocal folds of three rabbits were injected. The rabbits were then sacrificed, and laryngeal tissue was assessed histopathologically. All rabbits tolerated injection of Pc 4 and control solutions into buccal mucosa with no evidence of gross visual inflammatory changes and no changes in behavior or masticatory function. Histopathologic analysis of Pc 4 injected buccal and control mucosal tissue revealed mild focal histological changes and no stigmata of diffuse inflammatory reactions. The histopathologic analysis of Pc 4 injected into laryngeal tissue revealed similar findings with addition of mild eosinophilia in one sample. Direct mucosal injection of Pc 4 in rabbit buccal and vocal fold mucosae appears to be well tolerated with no gross inflammatory changes, and only mild histopathologic inflammatory changes observed. NA Laryngoscope, 2024.

Factors of postoperative recurrent laryngeal nerve paralysis and recovery of vocal cord movement in thyroid surgery

ObjectivePostoperative recurrent laryngeal nerve paralysis is one of the complications of thyroid surgery, and the prevention and management of paralysis is an important issue for surgeons. In this study, in order to gain further understanding of recurrent laryngeal nerve paralysis after thyroid surgery, we analyzed and examined the usefulness of nerve stimulators for recurrent laryngeal nerve paralysis and the factors that may cause recurrent laryngeal nerve paralysis. Furthermore, in cases where transient recurrent laryngeal nerve paralysis occurred, we analyzed and examined the timing of improvement in vocal cord movement for each intraoperative finding and intraoperative operation that caused the paralysis. MethodsAt the Department of Otorhinolaryngology Head and Neck Surgery, Sapporo Medical University Hospital, between January 2012 and December 2021, the subjects were 543 thyroid surgery cases (692 nerves) without preoperative paralysis or cancer nerve invasion performed. The relationship between postoperative transient and permanent paralysis of the recurrent laryngeal nerve was evaluated using univariate and multivariate analysis. The factors evaluated were gender, age, BMI, total thyroidectomy, benignity, malignancy, Graves’ disease, using IIONM (intermittent intraoperative nerve monitoring), using CIONM (continuous intraoperative nerve monitoring), malignant tumor T3b or higher, with lateral neck dissection, and years of experience of the surgeon. Furthermore, by targeting 87 nerves with transient paralysis, surgical operations were divided into three groups: minor injury, major injury, and adhesion, and their relationship with the timing of postoperative vocal fold movement improvement was evaluated. ResultsPermanent paralysis of the recurrent laryngeal nerve occurred in 12 nerves (1.7 %), and transient paralysis occurred in 100 nerves (14.5 %). Univariate analysis showed no association with each factor, but multivariate analysis showed that transient paralysis was significantly lower in men and in patients using IIONM. The improvement time for vocal cord paralysis was 2.8 months in the minor injury group, 4.5 months in the major injury group, and 3.2 months in the adhesion group, indicating a statistically significant difference between the minor injury group and the major injury group. ConclusionThis study suggests that the use of IIONM and gentle manipulation of women may prevent recurrent laryngeal nerve paralysis during thyroid surgery. In addition, understanding the period of nerve recovery for each operation for postoperative transient recurrent laryngeal nerve paralysis may contribute to patient explanations and determining the timing of therapeutic intervention for speech improvement surgery.

Linear effects of glucose levels on voice fundamental frequency in type 2 diabetes and individuals with normoglycemia

Glucose levels in the body have been hypothesized to affect voice characteristics. One of the primary justifications for voice changes are due to Hooke’s law, in which a variation in the tension, mass, or length of the vocal folds, mediated by the body’s glucose levels, results in an alteration in their vibrational frequency. To explore this hypothesis, 505 participants were fitted with a continuous glucose monitor (CGM) and instructed to record their voice using a custom mobile application up to six times daily for 2 weeks. Glucose values from CGM were paired to voice recordings to create a sampled dataset that closely resembled the glucose profile of the comprehensive CGM dataset. Glucose levels and fundamental frequency (F0) had a significant positive association within an individual, and a 1 mg/dL increase in CGM recorded glucose corresponded to a 0.02 Hz increase in F0 (CI 0.01–0.03 Hz, P < 0.001). This effect was also observed when the participants were split into non-diabetic, prediabetic, and Type 2 Diabetic classifications (P = 0.03, P = 0.01, & P = 0.01 respectively). Vocal F0 increased with blood glucose levels, but future predictive models of glucose levels based on voice may need to be personalized due to high intraclass correlation.

Long-term Results of Endoscopic Percutaneous Suture Lateralization for Newborns with Bilateral Vocal Cord Paralysis.

Bilateral vocal fold paralysis (BVFP) is a critical condition in newborns, which may present with significant airway distress necessitating tracheostomy. The purpose of this study is to report the safety and effectiveness of endoscopic percutaneous suture lateralization (EPSL) for newborns with BVFP, and evaluated the long-term results and the stability of the lateralization. A review of patients undergoing EPSL for BVFP at our institutions was performed between October 2018 and June 2023. Preoperative and postoperative clinical information was collected. The functional outcomes of the surgery in terms of breathing, voice, and swallowing were evaluated and recorded. Twenty seven patients were included, with a median age at diagnosis of 12 days (range, 1-33 days). The maximum follow-up is for 5 years. EPSL was successful in 77.8% of cases, effectively avoiding the need for tracheostomy. Dyspnea was relieved within a month after surgery, enabling patients to tolerate oral feeds within 2 months after surgery. Notably, some patients experienced a return of vocal fold function, particularly in successful EPSL cases, underlining the procedure's efficacy. Minor complications, including granulation tissue and wound infection, were observed but were manageable. Major complications were notably absent. The results are durable and stable at long-term follow-up. EPSL for BVFP is a relatively simple, minimally invasive, non-destructive, safe, and effective procedure in newborns, which may avoid the need for a tracheostomy, preserves the laryngeal framework, and does not affect the natural recovery of vocal cords. Level 3: retrospective case series Laryngoscope, 2024.

Applying Translaryngeal Ultrasonography in Unilateral Vocal Cord Paralysis before Thyroid Cancer Reoperation: A Single Center Study

Background: One of the most dangerous complications of thyroid surgery is recurrent laryngeal nerve (RLN) paralysis. The gold standard method to assess this damage is Videolaryngoscopy. However, we aimed to modify this approach by using Translaryngeal Ultrasonography (TLUS). We performed TLUS with a highly trained thyroid sonographer and an endocrine surgeon in 47 patients with recurrent thyroid cancer and unilateral RLN paralysis preoperatively, and compared the results with Videolaryngoscopy. The experienced sonographer identified 45 injuries in 47 patients, and the endocrine surgeon found 39 vocal cord injuries. It appears that TLUS, when performed by experienced practitioners, is a more accurate and safe modality for assessing vocal cord function in the preoperative setting of thyroid cancer reoperation.

Intraoperative neuromonitoring does not decrease the risk of vocal cord palsy associated with thyroid cancer surgeries, but cumulative experience over time may

Intraoperative neuromonitoring does not decrease the risk of vocal cord palsy associated with thyroid cancer surgeries, but cumulative experience over time may

Esophageal Dysmotility in Multiple System Atrophy: A Retrospective Cross-Sectional Study.

Background/Objective: Multiple system atrophy (MSA) is often associated with dysphagia and esophageal dysmotility (ED). However, ED in patients with MSA is poorly understood. To assess the relationship between ED, dysphagia, and other clinical findings in such patients and investigate the details of ED in MSA using high-resolution manometry (HRM). Methods: Patients from The University of Tokyo Hospital with MSA who underwent swallowing examinations, esophagography, and HRM between 2017 and 2022 were enrolled. A retrospective chart review of patients' backgrounds, swallowing function, and esophageal motility was performed. ED was evaluated using the Chicago Classification version 4.0. Results: Seventy-four patients with MSA were identified. The median age was 64 years, 48 patients (65%) were male, and the cerebellar variant type was predominant (69%). Abnormal upper esophageal sphincter (UES) resting pressure was observed in 34 patients (46%) and intraesophageal stasis in 65 (88%). High-severity MSA was a risk factor for developing dysphagia, vocal fold movement impairment, and abnormal UES function (p < 0.05). However, no overt clinical risk factors for ED were identified. Various types of ED were detected using HRM, and ineffective esophageal motility was the most frequent disorder. Conclusions: ED is a common occurrence in patients with MSA. Although a high-severity MSA may be a risk factor for developing dysphagia and vocal fold motion impairment, ED can occur regardless of clinical severity. Since ED is rarely detected based on subjective symptoms, careful evaluation of esophageal motility by esophagography or HRM is warranted in patients with MSA.

Establishing a Mouse Model of Surgical Vocal Fold Injury.

Animal models of vocal fold (VF) surgical injury and scar formation provide insight into the wound healing process. The purpose of this study was to establish an alternative model of surgical injury to the mouse VF using materials commonly available in most research laboratories or for purchase and to investigate wound healing of the epithelium (EP) and lamina propria (LP). Mice were anesthetized by isoflurane gas delivery and positioned on a platform so that the larynx could be observed using a laryngoscope and dissection microscope. Unilateral VF injury was created using a wire brush. Mice were euthanized and the larynx evaluated 1-, 3-, 5-, 7-, 14-, and 28-days following injury. Histological and immunofluorescent analysis was used to evaluate thickness of the EP, LP area, proliferative (Ki67+) and basal cells (p63+) in the EP, and collagen III content in the LP. The depth of injury reached the superficial thyroarytenoid muscle on Day 1. The thickness of the EP of the injured VF was increased on Days 3 and 5, and the LP area was increased on Days 3, 5, and 7 as compared with the uninjured VF. Ki67+ and p63+ cells were increased on Day 3 and collagen III content was increased on Days 5 and 28 as compared with the uninjured VF. We successfully established an alternative method of creating unilateral VF injury in the mouse. This method will be useful for future research regarding VF surgical injury and wound healing. N/A Laryngoscope, 2024.

Tyrosine-Like Crystalloids Localize to Non-Neoplastic True Vocal Cord and Attachments.

Tyrosine-rich or tyrosine-like crystalloids (TC) were initially described in salivary gland pleomorphic adenoma. The presence of TC in non-neoplastic tissues is rare, and it has been reported exclusively in the larynx. This study aims to characterize the frequency and anatomical localization of TC in total laryngectomy specimens. Review of consecutive laryngectomy specimens in which the cassette summary documented parasagittal section sampling of the right and left vocal folds and the anterior commissure. Data collected included patient demographics, underlying diagnoses, history of radiation therapy, presence, and location of TC. Of 86 laryngectomy specimens, 16 (19%) contained amphophilic to eosinophilic TC. The study cohort included 11 males and 5 females, aged 37 to 85 years (mean 62, median 63). Laryngectomy surgery was performed for advanced untreated squamous cell carcinoma (SCCa) (7/16, 43.75%), recurrent post-treatment SCCa (7/16, 43.75%), previously untreated laryngeal large cell neuroendocrine carcinoma (1/16, 6.25%), and non-functional larynx post-chemoradiation (1/16, 6.25%). According to the macroscopic cassette summary, TC were predominantly found in the anterior commissure Sect.(13/16, 81.25%), with fewer cases in sections containing the left (2/16, 12.5%) or the right (1/16, 6.25%) vocal folds. Microscopically, TC localized to the anterior macula flava and/or adjacent vocal ligament (12/16, 75%) and the anterior commissure tendon (4/16, 25%). TCs are predominantly reported as admixed with a neoplasm, however this study confirms that TC can also occur in non-neoplastic tissues of the larynx. There was no clear relationship between the presence of TC and prior radiation therapy. TC in the specialized connective tissues of the macula flava and true cord tendinous insertions distinct from tumor may form in response to alterations in mechanical stress, though an age-related change within the spectrum of normal laryngeal microanatomy also remains a possibility.