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The pathophysiology of laryngopharyngeal reflux (LPR) and its impact on the vocal fold is not well understood, but may involve acid damage to vocal fold barrier functions. Two different components encompass vocal fold barrier function: the mucus barrier and tight junctions. Mucus retained on epithelial microprojections protects the inside of the vocal fold by neutralizing acidic damage. Tight junctions control permeability between cells. Here we developed an in vitro experimental system to evaluate acidic injury and repair of vocal fold barrier functions. We first established an in vitro model of rat vocal fold epithelium that could survive at least one week after barrier function maturation. The model enabled repeated evaluation of the course of vocal fold repair processes. Then, an injury experiment was conducted in which vocal fold cells were exposed to a 5-min treatment with acidic pepsin that injured tight junctions and cell surface microprojections. Both of them healed within one day of injury. Comparing vocal fold cells treated with acid alone with cells treated with acidic pepsin showed that acidic pepsin had a stronger effect on intercellular permeability than acid alone, whereas pepsin had little effect on microprojections. This result suggests that the proteolytic action of pepsin has a larger effect on protein-based tight junctions than on phospholipids in microprojections. This experimental system could contribute to a better understanding of vocal fold repair processes after chemical or physical injuries, as well as voice problems due to LPR pathogenesis., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Masanobu Mizuta, Ichiro Tateya reports financial support was provided by Japan Society for the Promotion of Science. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Over the last decade, novel anticancer drugs have improved the prognosis for recurrent or metastatic squamous cell carcinoma of the head and neck (RM-SCCHN). However, this has increased healthcare expenditures and placed a heavy burden on patients and society. This study investigated the frequency of use and costs of select palliative chemotherapy regimens in Japan., Methods: From July 2021 to June 2022 in 54 healthcare facilities, we gathered data of patients diagnosed with RM-SCCHN and who had started first-line palliative chemotherapy with one of eight commonly used regimens. Patients with nasopharyngeal carcinomas were excluded. The number of patients receiving each regimen and the costs of each regimen for the first month and per year were tallied., Results: The sample comprised 907 patients (674 were < 75 years old, 233 were ≥ 75 years old). 330 (36.4%) received Pembrolizumab monotherapy, and 202 (22.3%) received Nivolumab monotherapy. Over 90% of patients were treated with immune checkpoint inhibitors as monotherapy or in combination with chemotherapy. Treatment regimens' first-month costs were 612 851-849 241 Japanese yen (JPY). The cost of standard palliative chemotherapy until 2012 was about 20 000 JPY per month. The incremental cost over the past decade is approximately 600 000-800 000 JPY per month, a 30- to 40-fold increase in the cost of palliative chemotherapy for RM-SCCHN., Conclusion: First-line palliative chemotherapy for RM-SCCHN exceeds 600 000 JPY monthly. Over the last decade, the prognosis for RM-SCCHN has improved, but the costs of palliative chemotherapy have surged, placing a heavy burden on patients and society., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Transoral robotic surgery (TORS), introduced by Weinstein et al. in 2005, has been widely adopted as a minimally invasive procedure, particularly for the treatment of patients with early stage oropharyngeal cancer. TORS is typically performed using the da Vinci Surgical System, similar to robot-assisted surgeries for other malignancies. The main difference between TORS and these other robot-assisted surgeries is that it is performed through the natural orifice of the mouth, which limits the surgical working space, and that it progresses from the lumen of the pharynx to the deeper tissues. The advantages of TORS are mainly due to the benefits of using the da Vinci Surgical System, such as three-dimensional high-definition images, magnification, multiple forceps articulation, tremor-stabilization function and motion scale function. To date, many big data and meta-analyses have shown that TORS is superior to conventional surgeries, such as open surgery, in terms of oncological outcomes, post-operative functionality and quality of life. In Japan, TORS is expected to spread across the country, as it has been covered by health insurance since April 2022. This review highlights the procedures of TORS, its unique aspects, its unparalleled advantages as a minimally invasive surgery for treating laryngeal and pharyngeal cancers, and its current status in Japan., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine., Methods: In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal., Results: Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach., Conclusion: This is the first report to show the feasibility of suturing the dural defect in deep-seated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

Background: We aimed to define the indications for sentinel lymph node biopsy (SLNB), the third option for cervical treatment in oral cancer with negative cervical lymph nodes., Methods: The greatest depth of invasion (DOI) and long diameter (LD) of the primary site were used as exposures. SLN metastasis was considered the outcome., Results: In three trials conducted between 2009 and 2016, 158 patients were eligible and reassigned to this study group. The scatterplot based on the respective values of DOI and LD would eventually be divided into three sections. In cases of sections T1, T2, and T3, the proportions of SLN metastasis positivity were 21.3%, 35.3%, and 51.2%, respectively. In certain cases of T1 with 2 mm < DOI ≤ 5 mm and 8 mm < LD ≤ 20 mm, the proportion of SLN metastasis positivity was 40.9%., Conclusions: SLNB-navigated or assisted neck dissection can be added as an effective procedure for N0 neck control., (© 2023 Wiley Periodicals LLC.)

In this study, we report a case of tracheotomy using the ex utero intrapartum treatment (EXIT) procedure in a fetus that was pointed out as having bilateral giant cervical cysts at prenatal diagnosis and whose postnatal airway occlusion was predicted. The subject was a female aged 35. She was diagnosed with polyhydramnios at 28 weeks of pregnancy. The fetus was found to have a giant cervical cyst before she was referred to the department of obstetrics and gynecology of our hospital. On the second day of 37 weeks of pregnancy, oral tracheal intubation was attempted on the fetus using the EXIT procedure after the caesarean operation, but intubation was difficult resulting in a tracheotomy. The oxygenation of the fetus during the operation was maintained well without any postoperative complication. Postnatal fetal airway occlusion is a critical incident which may lead to the death of a fetus. It was assumed, however, that the airway management under the same procedure was completed by the preoperative detailed simulation with the staff of the departments of anesthesiology, obstetrics and gynecology and pediatrics as well as the operating room personnel., Competing Interests: There is no conflict-of-interest to be disclosed concerning this article.

There are many methods and types of equipment for measuring the nasal airway, but there is no consensus regarding the results of various clinical studies on nasal obstruction. In this review, we discuss the two major methods of objectively assessing the nasal airway: rhinomanometry and acoustic rhinometry. The Japanese standard of rhinomanometry in Japanese adults and children was established by the Japanese Standardization Committee on Rhinomanometry in 2001 and 2018, respectively. However, the International Standardization Committee has proposed different standards because of differences in race, equipment, and social health insurance systems. The standardization of acoustic rhinometry in Japanese adults is making progress in several Japanese institutes, but the international standardization of acoustic rhinometry has not yet begun. Rhinomanometry is the physiological expression of nasal airway breathing, whereas acoustic rhinometry is the anatomic expression. In this review, we introduce the history and methods of the objective assessment of nasal patency and the physiological and pathological issues regarding nasal obstruction., Competing Interests: The authors declare that they have no conflict of interest.

Background: Endoscopic laryngopharyngeal surgery (ELPS) is a minimally invasive transoral surgery for superficial pharyngeal and laryngeal cancer, but dysphagia occasionally occurs post-treatment. We investigated dysphagia following ELPS and its risk factors., Methods: Of the 145 patients who underwent ELPS, 92 were evaluated in this study using the Hyodo score, Functional Outcome Swallowing Scale, Eating Assessment Tool-10 along with the total scores for the three items of the method of intake, time, and food preoperatively and on postoperative 1, 3, and 6 months. We examined the 6-month trends of these values. Furthermore, the fasting period post-surgery, the need for swallowing rehabilitation by a speech therapist, and postoperative pneumonia episodes were set as outcomes reflecting the short-term swallowing function. We determined the associations between these outcomes and patient background factors., Results: Postoperatively, the Hyodo score worsened at 1 month but recovered at 3 months. The Hyodo scores of all patients who underwent postcricoid ELPS did not worsen. The diameter of the resected specimen (DRS) was significantly associated with the need for swallowing rehabilitation and postoperative fasting time. A DRS ≥ 35 mm was considered the threshold for the need of swallowing rehabilitation, postoperative pneumonia, and prolonged postoperative fasting time., Conclusion: ELPS exerts a temporal and limited impact on the swallowing function, which recovers within 3 months in every swallowing evaluation. This necessitates additional care during the treatment of patients with mucosal defects ≥ 35 mm, owing to the significant association between the DRS and short-term swallowing function., (© 2023. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)

Objectives: Intraoperative cone beam computed tomography (CBCT) imaging has the potential to facilitate the surgical procedure. The current preliminary retrospective chart review investigated the benefits of intraoperative CBCT during laryngoplasty., Method: This study examined 26 cases that underwent intraoperative CBCT imaging during laryngoplasty, with one patient who counted twice due to first and revision surgery. The visual quality of structures of interest (glottal shape, thyroid cartilage, arytenoid cartilage, and implants) was determined using intraoperative CBCT during laryngoplasty. Each patient also underwent an aerodynamic assessment., Results: CBCT provided unique information, such as surgical landmarks in severe scarring, the subglottal shape, and the rotation angle of the arytenoid cartilage during arytenoid adduction. Nonetheless, 26.9% (7 of 26) of cases were affected by motion artifact, due to the long acquisition time. When motion artifact-negative cases were evaluated, 100% of glottal shape and more than 89% of thyroid cartilage were well visualized. All arytenoids were well-visualized in patients ≥ 50 years of age and without motion artifact, while CBCT failed to visualize the arytenoids in 2 of 4 patients who were < 50 years, due to the lack of calcifications. After medialization surgery, the yields of improved maximal phonation times (MPTs) in the motion artifact-negative and -positive groups were 8.7 sec and 3.4 sec, respectively (p = 0.032; Welch's t test). This comparison indicates intraoperative CBCT would contribute in MPT improvement, if CBCT is taken in measurable quality., Conclusion: The potential benefits of intraoperative CBCT during laryngoplasty were demonstrated. A corollary, prospective study is warranted to further confirmation., Competing Interests: Declaration of Competing Interest All authors participated have no financial support or relationship that causes a conflict of interest. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions., (Copyright © 2022. Published by Elsevier B.V.)

Introduction: Radiation-induced carotid artery stenosis (RI-CS) is known as one of long-term side effects of radiotherapy for head and neck cancer (HNC). However, the clinical time course after irradiation has been poorly understood. We aimed to investigate the natural history of radiation-induced carotid atherosclerosis, comparing the patients who received radiotherapy for HNC with the patients who were treated without radiotherapy., Methods: The patients who received treatment of HNC at Department of Otolaryngology, Head and Neck Surgery of Kyoto University Hospital, from November 2012 to July 2015 were enrolled. The patients were assigned into the RT group and the control group, depending on whether radiotherapy was planned or not. Annual carotid ultrasound was performed from the enrollment to 5 years. The increase of mean intima-media thickness (IMT) at common carotid artery from the enrollment (Δmean IMT) was evaluated., Results: Fifty-six patients in the RT group and 25 patients in the control group were enrolled. From 5-year follow-up data, the significant higher increase of Δmean IMT was consistently observed in the RT group than in the control group after 2 years. The RT group presented a 7.8-fold increase of mean IMT compared to the control group (0.060 mm per year in the RT group and 0.008 mm per year in the control group). Cumulative incidence curves obtained from the analysis of all vessels revealed that the RT group presented higher incidence of Δmean IMT ≥0.25 mm than the control group (p < 0.01). In the RT group, the patients with mean IMT ≥1.0 mm at enrollment exhibited significantly higher incidence of Δmean IMT ≥0.25 mm than the patients with mean IMT <1.0 mm (p < 0.01)., Discussion: Radiotherapy for HNC induces continuous carotid mean IMT progression. The irradiated carotid arteries with mean IMT ≥1.0 mm before radiotherapy presented earlier IMT progression than those with mean IMT <1.0 mm., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Objectives: The success of type 2 thyroplasty (TP2) for adductor spasmodic dysphonia (AdSD) depends on the selection of optimally sized titanium bridges, which requires accurate assessment of intraoperative vocal changes. While this procedure has traditionally been performed according to the laryngologist's experience, the most appropriate method for voice monitoring and selection of titanium bridge size remains to be determined. This study aimed to investigate evaluation parameters useful for voice monitoring, as these may allow less experienced surgeons to perform TP2 properly., Methods: In this prospective study, voice monitoring was performed in 18 patients with AdSD patients undergoing TP2. Evaluations were performed preoperatively, intraoperatively, 13 weeks postoperatively, and 52 weeks postoperatively using GRBAS (grade, roughness, breathiness, asthenia, and strain), as well as perceptual judgment and acoustic analyses., Results: Preoperative and intraoperative assessments of the G, R, B, and S parameters, perceptual judgment, and harmonic-to-noise ratio (HNR) were in moderate or better agreement. Intraoperative and 13- or 52-week postoperative measurements of the R, B, and G parameters and strangulation, tremor, and HNR were also in high agreement. When two different sizes of titanium bridges were compared (unselected vs. selected), ratings for G, R, S, strangulation, tremor, jitter, shimmer, HNR, standard deviation of F0, and degree of voice breaks were better for the selected width than the unselected width., Conclusion: The candidate items for intraoperative voice monitoring during TP2 for AdSD are G, R, strangulation, tremor, and HNR. The use of these items may help to ensure successful TP2 and contribute to the advancement of laryngeal framework surgery., Level of Evidence: Level 4., Competing Interests: The authors have no conflicts of interest directly relevant to the content of this article., (© 2022 The Authors. Laryngoscope Investigative Otolaryngology published by Wiley Periodicals LLC on behalf of The Triological Society.)

Objective: Some patients with cleft palate (CP) need secondary surgery to improve functionality. Although 4-dimensional assessment of velopharyngeal closure function (VPF) in patients with CP using computed tomography (CT) has been existed, the knowledge about quantitative evaluation and radiation exposure dose is limited. We performed a qualitative and quantitative assessment of VPF using CT and estimated the exposure doses., Design: Cross-sectional., Setting: Computed tomography images from 5 preoperative patients with submucous CP (SMCP) and 10 postoperative patients with a history of CP (8 boys and 7 girls, aged 4-7 years) were evaluated., Patients: Five patients had undergone primary surgery for SMCP; 10 received secondary surgery for hypernasality., Main Outcome Measures: The presence of velopharyngeal insufficiency (VPI), patterns of velopharyngeal closure (VPC), and cross-sectional area (CSA) of VPI was evaluated via CT findings. Organ-absorbed radiation doses were estimated in 5 of 15 patients. The differences between cleft type and VPI, VPC patterns, and CSA of VPI were evaluated., Results: All patients had VPI. The VPC patterns (SMCP/CP) were evaluated as coronal (1/4), sagittal (0/1), circular (1/2), and circular with Passavant's ridge (2/2); 2 patients (1/1) were unevaluable because of poor VPF. The CSA of VPI was statistically larger in the SMCP group ( P = .0027). The organ-absorbed radiation doses were relatively lower than those previously reported., Conclusions: Four-dimensional CT can provide the detailed findings of VPF that are not possible with conventional CT, and the exposure dose was considered medically acceptable.

As the laryngopharynx is closely related to swallowing, speech, and phonation, it is necessary to consider not only disease control but also a minimally invasive approach for the treatment of laryngopharyngeal cancer. Transoral surgery has been reported to be a minimally invasive method for treating these diseases. Transoral videolaryngoscopic surgery (TOVS) and endoscopic laryngo-pharyngeal surgery (ELPS) have been developed in Japan and recently emerged as treatments for patients with early stage pharyngeal and laryngeal cancers. However, securing an appropriate field of view and a narrow operating space during TOVS or ELPS are critical issues to be resolved for these surgeries. The clinical significance and safety of transoral robotic surgery (TORS) using the da Vinci Surgical System have been widely reported to provide surgeons with increased visualization and magnification, resulting in precise surgical margins and rapid functional recovery. In this context, a multi-institutional clinical study was conducted to evaluate the treatment outcomes of TORS for the treatment of laryngopharyngeal cancer in Japan, and the da Vinci Surgical System for oral robot-assisted surgery for these diseases was approved by the Pharmaceutical Affairs Agency in August 2018. This review provides an overview of the therapeutic effects of TOVS, ELPS, and TORS, with a particular focus on these therapeutic results in Japan., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sano, Shimizu, Tateya, Fujiwara, Kishimoto, Maruo, Fujimoto, Mori, Kato, Tsukahara and Oridate.)

Purpose: Auditory-perceptual evaluation is essential for the assessment of voice quality. The Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) provides a standardized protocol and assessment form for clinicians to analyze the voice quality and has been adapted into several different languages. The aims of this study were to develop the Japanese version of the CAPE-V and to investigate its reliability and validity., Method: The Japanese CAPE-V consisted of the same three speech contexts (vowels, sentences, and conversation) as developed in the original English version. The sentences were designed according to the concepts of the original version and reviewed by Japanese phoneticians. To validate the usefulness of the Japanese CAPE-V, voices of 173 Japanese-speaking subjects (76 subjects with dysphonia and 97 without voice complaints) were evaluated by five experienced judges, according to the Japanese CAPE-V as well as the GRBAS (Grade, Roughness, Breathiness, Asthenia, Strain) scale., Results: The Japanese CAPE-V provided a high interrater reliability (intraclass correlation coefficients [ICCs] > .85 for all the parameters) as well as a high intrarater reliability (ICCs > .85 for all the parameters). In addition, overall severity, roughness, and breathiness in the Japanese CAPE-V were highly correlated with the corresponding dimensions in the GRBAS scale, having Spearman correlation coefficients greater than .8., Conclusion: This study demonstrated the reliability and validity of the newly developed Japanese CAPE-V as an auditory-perceptual evaluation instrument.

Tissue-engineered tracheae have been developed to replace defective tracheae. However, the direction of ciliated cells in the regenerated epithelium remains unclear. We investigated planar polarity formed in the regenerated airway epithelium after tracheal graft implantation. We partially resected the rat trachea and implanted a collagen scaffold. The direction of the basal foot was assessed by transmission electron microscopy. Immunofluorescence staining was performed to examine the biased distribution of Vangl1 and Frizzled6 proteins. The direction of mucociliary transport was analyzed by video microscopy. Our results showed that the basal feet of cilia in the proximal and distal regions of the implanted areas were respectively oriented toward the proximal and distal directions. The biased distribution of Vangl1 and Frizzled6, and the directions of mucociliary transport showed that planar polarities formed in the regenerated epithelium were oriented toward the proximal, distal, left, and right directions in the proximal, distal, left, and right regions of the implanted area. These polarities persisted until nine months after implantation. Hence, the results suggest that planar polarities formed in epithelia regenerated on tracheal grafts are directed toward the nearby edges of implanted areas and are preserved for a prolonged period. The polarities can, at least partially, contribute to clearing external materials from the implanted areas by transporting them to a normal region., (© 2021 John Wiley & Sons Ltd.)

Secretory carcinoma or mammary analog secretory carcinoma is an entity of salivary gland carcinoma that is characterized by the ETV6-NTRK3 gene fusion. Although it is generally considered to be a low-grade malignancy, some cases of secretory carcinoma with high-grade transformation (SCHG) have been reported. We herein describe a case of SCHG composed almost exclusively of the high-grade component. The patient presented with a growing mass in the buccal mucosa and underwent surgery. Tumor cells showing high-grade nuclear atypia were arranged in solid or cribriform nests with comedo-like necrosis. A differential diagnosis included high-grade salivary gland carcinoma, such as salivary duct carcinoma. Immunohistochemically, tumor cells were focally positive for S-100 and negative for mammaglobin and showed nuclear positivity for pan-Trk. A reverse transcription polymerase chain reaction assay showed that the tumor harbored the ETV6-NTRK3 gene fusion. A histological review of microscopic slides of the tumor did not reveal a typical secretory carcinoma component, except for a very focal area. We ultimately diagnosed this tumor as SCHG. This case underscores the importance of recognizing the histological spectrum of SCHG and the utility of pan-Trk immunohistochemistry to detect secretory carcinoma, which may be targeted by tyrosine kinase inhibitors., (© 2021 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Head and neck cancers, especially in hypopharynx and oropharynx, are often detected at advanced stage with poor prognosis. Narrow band imaging enables detection of superficial cancers and transoral surgery is performed with curative intent. However, pathological evaluation and real-world safety and clinical outcomes have not been clearly understood. The aim of this nationwide multicenter study was to investigate the safety and efficacy of transoral surgery for superficial head and neck cancer. We collected the patients with superficial head and neck squamous cell carcinoma who were treated by transoral surgery from 27 hospitals in Japan. Central pathology review was undertaken on all of the resected specimens. The primary objective was effectiveness of transoral surgery, and the secondary objective was safety including incidence and severity of adverse events. Among the 568 patients, a total of 662 lesions were primarily treated by 575 sessions of transoral surgery. The median tumor diameter was 12 mm (range 1-75) endoscopically. Among the lesions, 57.4% were diagnosed as squamous cell carcinoma in situ. The median procedure time was 48 minutes (range 2-357). Adverse events occurred in 12.7%. Life-threatening complications occurred in 0.5%, but there were no treatment-related deaths. During a median follow-up period of 46.1 months (range 1-113), the 3-year overall survival rate, relapse-free survival rate, cause-specific survival rate, and larynx-preservation survival rate were 88.1%, 84.4%, 99.6%, and 87.5%, respectively. Transoral surgery for superficial head and neck cancer offers effective minimally invasive treatment. Clinical trials registry number: UMIN000008276., (© 2021 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: Involvement in the tracheostomy procedure for COVID-19 patients can lead to a feeling of fear in medical staff. To address concerns over infection, we gathered and analyzed experiences with tracheostomy in the COVID-19 patient population from all over Japan., Methods: The data for health-care workers involved in tracheostomies for COVID-19-infected patients were gathered from academic medical centers or their affiliated hospitals from all over Japan., Results: Tracheostomies have been performed in 35 COVID-19 patients with a total of 91 surgeons, 49 anesthesiologists, and 49 surgical staff members involved. Twenty-eight (80%) patients underwent surgery more than 22 days after the development of COVID-19-related symptoms (11: 22-28 days and 17: ≥29 days). Thirty (85.7%) patients underwent surgery ≥ 15 days after intubation (14: 15-21 days, 6: 22-28 days, and 10: ≥29 days). Among the total of 189 health-care workers involved in the tracheostomy procedures, 25 used a powered air-purifying respirator (PAPR) and 164 used a N95 mask and eye protection. As a result, no transmission to staff occurred during the 2 weeks of follow-up after surgery., Conclusion: No one involved in tracheostomy procedures were found to have been infected with COVID-19 in this Japanese study. The reason is thought to be that the timing of the surgery was quite late after the infections, and the surgery was performed using appropriate PPE and surgical procedure. The indications for and timing of tracheostomy for severe COVID-19 patients should be decided through multidisciplinary discussion., Competing Interests: Declaration of Competing Interest We declare that we have no conflicts of interest., (Copyright © 2021. Published by Elsevier B.V.)

Objectives: The aim of this multicenter retrospective cohort study was to compare efficacy and subsequent postoperative treatment between transoral robotic surgery (TORS) and any non-robotic transoral surgery in Japanese patients with early oropharyngeal squamous cell carcinoma (OPSCC), hypopharyngeal SCC (HPSCC), or supraglottic SCC (SGSCC)., Materials and Methods: Clinical information and surgical outcomes were compared between patients with early-stage OPSCC, HPSCC, and SGSCC who underwent TORS (TORS cohort) and those who underwent non-robotic transoral surgery, including transoral videolaryngoscopic surgery (TOVS), endoscopic laryngopharyngeal surgery (ELPS), and transoral laser microsurgery (TLM) (non-robotic cohort). The data of the Head and Neck Cancer Registry of Japan (registry cohort) were used to validate the comparison. The main outcomes were the presence of positive margins under pathology and the requirement for postoperative therapy, including radiotherapy or chemoradiotherapy., Results: Sixty-eight patients in the TORS cohort, 236 patients in the non-robotic cohort, and 1,228 patients in the registry cohort were eligible for this study. Patients in the TORS cohort were more likely to have oropharyngeal tumor disease and T2/3 disease than those in the other cohorts (P<0.001 and P=0.052, respectively). The TORS cohort had significantly fewer patients with positive surgical margins than the non-robotic cohort (P=0.018), as well as fewer patients who underwent postoperative treatment, although the difference was not significant (P=0.069). In the subgroup analysis of patients with OPSCC, a total of 57 patients in the TORS cohort, 73 in the non-robotic cohort, and 171 in the registry cohort were eligible for the present study. Patients with OPSCC who underwent TORS were more likely to have lateral wall lesions than those in the other cohorts (P=0.003). The TORS cohort also had significantly fewer patients with positive surgical margins than the non-robotic cohort (P=0.026), and no patients in the TORS cohort underwent any postoperative treatment for OPSCC, although the difference was not significant (P=0.177)., Conclusions: Our results suggest that TORS leads to fewer positive surgical margins than non-robotic transoral surgeries. The clinical significance of TORS may be further validated through the results of all-case surveillance for patients who underwent TORS running in Japan in the future., (Copyright © 2021. Published by Elsevier B.V.)

Many patients with allergic rhinitis have accompanying laryngeal symptoms such as persistent cough and/or globus. Chronic laryngeal allergy is suspected to be an important cause of these laryngeal symptoms. We have been working toward establishing the concept of a new pathological condition termed "laryngeal allergy" since 1988. In Japan, the first diagnostic criteria for laryngeal allergy were established in 1995. However, these early criteria were inadequate because there was inadequate distinction between laryngeal allergy and other causes of persistent cough and globus. Therefore, more advanced criteria were reconstructed from a completely different viewpoint in 2005 to correctly distinguish laryngeal allergy from other similar diseases. The criteria established in 2005 were modified slightly in 2011 to improve the diagnostic accuracy based on the results of fundamental and clinical investigations. The Japanese Respiratory Society (JRS) included chronic laryngeal allergy in the diagnostic flowchart of the JRS guidelines for the management of cough and sputum in 2019, and chronic laryngeal allergy has recently gained wider recognition in Japan. The accurate diagnosis of conditions resembling laryngeal allergy is important in controlling cough and/or globus and preventing the unnecessary use of medical resources. Therefore, further investigations are warranted to better understand laryngeal allergy and similar diseases., Competing Interests: The authors declare that they have no conflict of interest.

Spasmodic dysphonia (SD) is characterized by an involuntary laryngeal muscle spasm during vocalization. Previous studies measured brain activation during voice production and suggested that SD arises from abnormal sensorimotor integration involving the sensorimotor cortex. However, it remains unclear whether this abnormal sensorimotor activation merely reflects neural activation produced by abnormal vocalization. To identify the specific neural correlates of SD, we used a sound discrimination task without overt vocalization to compare neural activation between 11 patients with SD and healthy participants. Participants underwent functional MRI during a two-alternative judgment task for auditory stimuli, which could be modal or falsetto voice. Since vocalization in falsetto is intact in SD, we predicted that neural activation during speech perception would differ between the two groups only for modal voice and not for falsetto voice. Group-by-stimulus interaction was observed in the left sensorimotor cortex and thalamus, suggesting that voice perception activates different neural systems between the two groups. Moreover, the sensorimotor signals positively correlated with disease severity of SD, and classified the two groups with 73% accuracy in linear discriminant analysis. Thus, the sensorimotor cortex and thalamus play a central role in SD pathophysiology and sensorimotor signals can be a new biomarker for SD diagnosis.

Objectives/hypothesis: To regenerate defected recurrent laryngeal nerves (RLNs), various methods have been developed. However, no consistently effective treatments are currently available because of their insufficient functional recovery. RADA16-I, a self-assembling peptide used clinically as a hemostat, reportedly supports neurite outgrowth and functional synapse formation in vitro. The purpose of this study was to investigate the effect of RADA16-I hydrogels on transected RLNs in rats., Study Design: Animal experiments with controls., Methods: Fifteen adult rats were divided into the following three groups: RADA16-I (+), RADA16-I (-), and neurectomy. A 6-mm gap of the left RLN was bridged using an 8-mm silicone tube in the RADA16-I (-) and RADA16-I (+) groups. Subsequently, RADA16-I hydrogel was injected into the tube in the RADA16-I (+) group. The surgical incisions were closed without any further treatment in the neurectomy group. After 8 weeks, laryngoscopy and electrophysiological and histological examinations were performed to evaluate the effect of RADA16-I on nerve regeneration and thyroarytenoid muscle atrophy., Results: Although most rats in the three groups exhibited no improvements of their vocal fold movement, partial recovery was observed in one rat in the RADA16-I (+) group. The neurofilament-positive areas and the number of myelinated nerves in the RADA16-I (+) group were significantly higher than in the RADA16-I (-) group. The area of the left thyroarytenoid muscle in the RADA16-I (+) group was significantly larger than that of the neurectomy group., Conclusions: Our results suggested that RADA16-I hydrogel was effective for RLN regeneration., Level of Evidence: NA Laryngoscope, 130:2420-2427, 2020., (© 2019 The American Laryngological, Rhinological and Otological Society, Inc.)

Multiciliated epithelial cells in the airway are essential for mucociliary clearance. Their function relies on coordinated, metachronal and directional ciliary beating, appropriate mucus secretion and airway surface hydration. However, current conventional methods for observing human airway ciliary movement require ciliated cells to be detached from airway tissues. Determining the directionality of cilia is difficult. We developed a novel method to stain airway epithelial cilia to observe their movement without releasing ciliated cells. Human tracheae were obtained from patients (n = 13) who underwent laryngectomies to treat malignancies or swallowing disorders. The tracheae were treated with fluorescently labeled wheat germ agglutinin, which interacts with the acidic mucopolysaccharides present on the cilia. Epithelial surfaces were observed using an epi-fluorescence microscope equipped with a water-immersion objective lens and a high-speed camera. Ciliary movement was observable at 125 fps (13/13 samples). Ciliated cells in close proximity mostly exhibited well-coordinated ciliary beats with similar directionalities. These findings indicated that wheat germ agglutinin renders ciliary beats visible, which is valuable for observing human airway ciliary movements in situ.

Objectives: Transoral approaches for laryngeal/pharyngeal malignancies have been widely accepted as minimally invasive treatment options; however, hypopharyngeal lesions treated by transoral surgery have rarely been reported due to the difficulties in visualizing the hypopharynx. Since 2010, we have treated superficial hypopharyngeal lesions with endoscopic laryngopharyngeal surgery (ELPS), and herein report the outcomes of this transoral procedure., Materials and Methods: One hundred and eighteen patients with superficial hypopharyngeal lesions were treated by ELPS from February 2010 to February 2017, and the clinical courses of the patients were reviewed., Results: Four females and 114 males (average: 65.6 y-o) were included in this study. Some patients had multiple lesions and a total of 154 superficial hypopharyngeal lesions (dysplasia: 29, Tis: 52, T1: 44, T2: 20, T3: 9) were treated with ELPS. Ten patients had only dysplasia and no carcinoma. Five patients presented with nodal metastases and 11 patients had simultaneous oropharyngeal lesions. In all cases, the hypopharynx was well visualized with sufficient working space, and no cases required a change in surgical approach. All post-operative complications were safely managed. In regard to the oncological outcomes, of the 108 patients with malignant lesions, the 3-year and 5-year overall survival (OS) rate was 93.6% and 85.5%, respectively., Conclusions: During ELPS, the hypopharynx was well visualized providing sufficient working space for the resection. The procedure was safe and feasible for superficial hypopharyngeal lesions and exhibited very good oncological outcomes. ELPS is thought to be a very effective surgical alternative for superficial hypopharyngeal lesions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The tracheal lumen is essential for conducting air to the lung alveoli and for voice production. However, patients with severe tracheal stenosis and malignant tumors invading the trachea often require tracheal resection. Recently, various reported tissue engineering methods for tracheal reconstruction show that regeneration of ciliated epithelium in the reconstructed areas, as well as preservation of the luminal structure is possible. However, only few studies report on the mucociliary transport function in reconstructed tracheae. We investigated mucociliary transport function within rat tracheal epithelium, reorganized after autologous adipose tissue-derived stem cell (ASC) transplantation. Rat ASCs were expanded in culture, and then seeded in a collagen sponge, which was physically supported with a polypropylene framework. The ASC-seeded collagen sponge was transplanted into the rat tracheal defect. We then examined the motility and transport function of cilia generated in the transplanted area using ciliary beat frequency (CBF) and microsphere movement analyses. Our data suggested that autologous ASC transplantation promoted ciliogenesis, consistent with previous reports. The CBF analysis revealed that motility of the cilia generated in the ASC group was comparable to that observed in the normal rat tracheal epithelium. Transport function in the ASC group was higher than that in the control group. These data suggested that autologous ASC transplantation increased ciliated cells in the reconstructed area without significantly disrupting cilia motility, thereby promoting transport function regeneration. Autologous ASC transplantation is expected to be beneficial in morphological and functional regeneration of tracheal epithelium. Anat Rec, 303:471-477, 2020. © 2019 American Association for Anatomy., (© 2019 Wiley Periodicals, Inc.)

Objective: To develop a summary of the first version of the Clinical Practice Guideline of Voice Disorders for Diagnosis, Management, and Treatment in Japan by the Clinical Practice Guideline Committee of the Japan Society of Logopedics and Phoniatrics and The Japan Laryngological Association. The 2018 recommendations, based on a review of the scientific literature, are intended to serve as clinical practice guidelines for the diagnosis, management, and treatment of voice disorders in Japan., Methods: A summary of the original version of the Clinical Practice Guideline of Voice Disorders for Diagnosis, Management, and Treatment in Japan was described. Recommendations for the diagnosis, management, and treatment of voice disorders were prepared. Twelve clinical questions (CQs) regarding the diagnosis, management, treatment, and effectiveness of therapy for voice disorders were also prepared., Results: A summary of the first version of the clinical practice guidelines for the diagnosis, management, and therapy of voice disorders was prepared and is presented. Additionally, answers to the 12 CQs on the diagnosis, management, treatment, and effectiveness of voice disorder therapy were prepared, and include evidence-based recommendations., Conclusion: These guidelines present a summary of the standard approaches for the diagnosis and treatment of voice disorders and relevant CQs that consider the medical environments in Japan. We hope that the guidelines will assist physicians in clinical settings for patients with voice disorders., (Copyright © 2019. Published by Elsevier B.V.)

Objective: Salivary gland carcinoma is rare among head and neck cancers. Sublingual gland carcinoma, a type of salivary gland carcinoma, is even rarer; therefore, the number of cases at a single institute is too small for sufficient evaluation of tumor characteristics. We conducted a multicenter, retrospective analysis of sublingual gland carcinomas in patients who visited 12 institutions associated with the Kyoto Hospital and Affiliated Facilities Head and Neck Clinical Oncology Group., Methods: Thirteen previously untreated patients who visited the institutions between 2006 and 2015 were enrolled. The overall survival (OS) and disease-free survival (DFS) rates for all patients and by disease stage were analyzed. Statistical analyses were performed for all patients with respect to disease stage., Results: Eight of thirteen patients were diagnosed with adenoid cystic carcinoma on pathological study. A significant difference in OS rate was observed between patients with Stage I-III and Stage IV disease; however, the difference in DFS rate by disease stage was not significant., Conclusion: Stage IV disease was identified as a poor prognostic factor in patients with sublingual gland carcinoma. However, even patients with Stage I-III disease experienced relatively short DFS. Distant metastasis is a serious problem among patients with sublingual gland carcinoma., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: The indication of transoral robotic surgery for hypopharyngeal cancer is limited because of poor accessibility. The aim of this study was to explore the efficacy of a curved laryngopharyngoscope used in combination with a next-generation flexible robotic surgical system for accessing and resecting the hypopharynx., Methods: A comparative evaluation of the curved laryngopharyngoscope versus standard straight-blade retractors using the flexible robotic surgical system was conducted on 2 cadavers. End points measured included visualization, accessibility, and ease of dissection for accessing and resecting the hypopharynx., Results: Visualization, accessibility, and dissection were superior with the curved laryngopharyngoscope in all subareas of the hypopharynx. The advantages of accessibility and visualization were much more evident in the cadaver with a high body mass index., Conclusions: These preclinical data suggest that using a curved laryngopharyngoscope in combination with a flexible robotic surgical system may lead to technical innovations concerning transoral surgery of the hypopharynx.

Recently, a global phase III study demonstrated that nivolumab markedly improved patient outcomes in recurrent or metastatic head and neck carcinoma (RMHNC). However, the efficacy of nivolumab in patients who are ineligible for clinical trials is unknown. We investigated nivolumab efficacy in real-world patients and prognostic factors associated with the response to nivolumab. This study was conducted at 11 institutes associated with Kyoto University and its Affiliated Hospitals-Head and Neck Oncology Group. In total, 93 patients with RMHNC who received nivolumab between May 2017 and May 2018 were retrospectively reviewed. Objective response rate (ORR), overall survival, and progression-free survival (PFS) were evaluated. Univariate and multivariate analyses were performed to identify prognostic factors. The ORRs in patients with squamous cell carcinoma (SCC) and non-SCC were 21.8% and 0%, respectively. In patients with SCC and non-SCC, the 1-year PFS rates were 28.7% and 8.9%, respectively. The hazard ratio (HR) for risk of PFS events (SCC versus non-SCC) was 2.28 (95% confidence interval: 1.21-4.1; log-rank p = 0.007). Univariate and multivariate analyses revealed radiotherapy history, platinum-refractory carcinoma, and treatment-related adverse events (TRAEs) as important prognostic factors associated with PFS in patients with SCC. In a real-world setting, non-SCC and platinum-refractory carcinoma were associated with a poorer prognosis, and a history of radiotherapy to the primary tumor, and the occurrence of TRAEs were associated with a better prognosis. These findings could be useful for clinicians and patients when selecting a treatment strategy.

Liposarcoma is one of the most common soft tissue tumors that affect adults. Liposarcoma is typically identified in the retroperitoneum, trunk and extremities as a slow-growing mass, yet is rare in the thyroid gland. Herein, we report a case of dedifferentiated liposarcoma that developed in the thyroid gland, and performed a literature review. A 66-year-old male with a history of well-differentiated liposarcoma in the thymus presented with a rapidly enlarging mass in the thyroid gland. Malignancy was suspected due to the local extension of the tumor, and complete resection of the tumor was achieved. Tissue diagnosis from the tumor following surgery revealed that dedifferentiated liposarcoma, and tumor progression was difficult to control with adjuvant radiation and chemotherapy. This is, to the best of our knowledge, the first case to report dedifferentiated liposarcoma in the thyroid gland, and the difficulty in initial diagnosis as well as the aggressive features of dedifferentiated liposarcoma are highlighted.

Tracheal resection is often performed for malignant tumours, congenital anomalies, inflammatory lesions, and traumatic injuries. There is no consensus on the best approach for the restoration of tracheal functionality in patients with tracheal defects. Artificial grafts made of polypropylene and collagen sponge have been clinically used by our group. However, 2 months are required to achieve adequate epithelialization of the grafts in humans. This study aimed to investigate the feasibility of transplantation therapy using an artificial trachea with human-induced pluripotent stem cell (hiPSC)-derived multiciliated airway cells (hiPSC-MCACs). Collagen vitrigel membrane, a biocompatible and absorbable material, was used as a scaffold to cover the artificial trachea with hiPSC-MCACs. Analyses of hiPSC-MCACs on collagen vitrigel membrane were performed by immunocytochemistry and electron microscopy and by assessing ciliary beat frequency. Along with the artificial trachea, hiPSC-MCACs were transplanted into surgically created tracheal defects of immunodeficient rats. The survival of transplanted cells was histologically evaluated at 1 and 2 weeks after the transplantation. The hiPSC-MCACs exhibited motile cilia on collagen vitrigel membrane. The surviving hiPSC-MCACs were observed in the endotracheal epithelium of the tracheal defect at 1 and 2 weeks after transplantation. These results suggest that hiPSC-MCAC is a useful candidate for tracheal reconstruction., (© 2019 John Wiley & Sons, Ltd.)

Tracheal epithelia have barrier and mucociliary clearance functions that prevent invasion of extraneous particles and infectious materials. Hence, following tracheal reconstructions, functional and morphological regeneration of epithelia is required to prevent respiratory declines and infectious diseases. Although growth factors (GFs) promote the regeneration of tracheal epithelial morphologies, it remains unclear whether tracheal grafts containing GFs are beneficial for regeneration of tracheal epithelial functions. Thus, we fabricated collagen sponge scaffolds containing insulin-like GF-1 (IGF-1) and the basic fibroblast, hepatocyte, and epidermal GFs (bFGFs, HGFs, and EGFs, respectively), and we evaluated the effects of the grafts on the functional regeneration of tracheal epithelia. Partial tracheal defects were imposed surgically, and collagen sponges containing IGF-1, bFGF, HGF, or EGF were then transplanted to defect sites. Subsequent immunofluorescence studies suggested that EGF and bFGF contribute to regular distributions of tight junction molecules, and tracer permeability assays suggested that EGF and bFGF promote regeneration of barrier function. Increased ciliogenesis was also observed using scanning electron microscopy in reconstructed regions treated with EGF- and bFGF-supplemented collagen sponges. However, bFGF-supplemented collagen sponges led to greater microsphere transport than did EGF-supplemented sponges. The present data suggested that collagen sponge scaffold containing bFGF promotes functional regeneration of tracheal epithelial tissues., (© 2019 John Wiley & Sons, Ltd.)

Objective: Due to the rising number of elderly patients and advances in endoscopic devices, early laryngeal and pharyngeal cancers are increasingly found in elderly patients. In these cases, minimally invasive endoscopic larygo-pharyngeal surgery (ELPS) may be indicated. However, the safety and efficacy of ELPS in elderly populations has not been established. The purpose of this study was to investigate the safety, outcomes and feasibility of ELPS in very elderly patients., Methods: Between February 2010 and April 2016, 29 pharyngeal cancerous or pre-cancerous lesions in 19 patients aged 75 years or older were treated with ELPS. Twenty-six resections were performed in total, and the patients' clinical courses were reviewed., Results: Sixteen patients had multiple comorbidities and moderate to severe comorbidities were observed in 17 patients. The average surgical time and hospitalization period was 54.3min and 18.8 days, respectively. On average, oral intake began 4.4days after the procedure, and all patients eventually received nourishment by mouth; no percutaneous endoscopic gastrostomy dependency was observed. Complications included post-operative bleeding and aspiration pneumonia in two cases each, and all complications were safely managed. The 3-year overall survival rate was 90.2% and the 3-year disease-specific survival rate was 100%., Conclusion: ELPS was safely performed in elderly patients, suggesting that it is a feasible treatment option for pharyngeal lesions in very elderly patients., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: Macrophages are prominent inflammatory cells in wounds, and their phenotypes are altered during wound healing. They are reported to contribute to not only inflammatory responses but also tissue remodeling. However, few studies in vocal fold biology have focused on the function of macrophages. The purpose of this study was to investigate macrophage polarization and distribution in injured murine vocal folds., Study Design: Animal experiments with controls., Method: Unilateral vocal fold stripping was performed on C57BL/6 mice, and larynges were harvested 1, 3, 5, 7, and 14 days postinjury. Immunohistochemical analysis of the vocal fold lamina propria was performed to detect the expression of classically activated (M1) and alternatively activated (M2) macrophage markers (inducible nitric oxide synthase [iNOS] and CD206, respectively) in F4/80 + macrophages., Results: The proportion of F4/80 + iNOS + cells out of all F4/80 + cells tended to increase from day 1. F4/80 + iNOS + cell percentage tended to be high at days 1 through 7 and declined to close to a normal level by day 14. F4/80 + CD206 + cell percentage tended to decrease at day 1 and then to increase the rest of the time. In the normal vocal fold, the majority of F4/80 + macrophages were only positive for CD206. F4/80 + iNOS + CD206 + cells were observed at days 1 through 7., Conclusion: The main population of injured sites gradually shifted from M1 to M2 marker-positive macrophages in murine vocal folds. However, coexistence of M1 and M2 markers in the same macrophages was observed. Our results suggest that macrophage phenotypes are regulated by complex tissue-derived signals and exhibit dynamic changes during wound healing., Level of Evidence: NA Laryngoscope, 129:E135-E142, 2019., (© 2018 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: To elucidate the aging physiology of the vocal folds, we examined the characters of aged vocal fold fibroblasts (VFFs) in various conditions., Study Design: In vitro study., Methods: VFFs from young (12-week-old) and aged (19-month-old) Sprague-Dawley rats were compared. Proliferative capacity, ratio of myofibroblast to fibroblast, myofibroblast function, and extracellular matrix production were examined in the following conditions: naïve, basic fibroblast growth factor (bFGF) supplemented, and hepatocyte growth factor (HGF) supplemented., Results: Aged VFFs demonstrated reduced proliferation by cell counting, though the ratio of Ki-67-positive cells showed no difference. Aged VFFs exhibited an increased expression of α-smooth muscle actin (α-SMA); however, they demonstrated no enhanced contractile ability in a gel contraction assay. Type I collagen protein was increased age dependently, accompanied with decreased Mmp1 and unchanged Col1a1 transcription. Type I collagen protein and α-SMA represented quite similar reduction patterns to bFGF or HGF administration., Conclusions: The following possible characteristics of aged VFFs were implied: long duration of mitosis, increased myofibroblast population size with certain dysfunctions, reduced type I collagen turnover, and correlation between α-SMA expression and type I collagen metabolism. Further investigations of these features will help to clarify presbyphonia's pathology and establish treatment strategies., Level of Evidence: NA Laryngoscope, 129:E94-E101, 2019., (© 2018 The American Laryngological, Rhinological and Otological Society, Inc.)

Objective: Clinical studies demonstrating the prognostic factors in submandibular gland carcinoma are limited because the tumor is relatively rare. The aim of this study was to identify clinical outcomes and prognostic factors in submandibular gland carcinoma., Methods: The study included 65 patients with submandibular gland carcinoma who underwent initial surgical treatment at the Kyoto University and its affiliated hospitals., Results: The 3-year overall survival (OS), disease specific survival, locoregional control (LRC), and no distant metastasis (NDM) rates were 74.2%, 74.2%, 90.0%, and 64.8%, respectively. In the current follow-up study, 16 patients died of the disease, 5 patients were alive with recurrence, 43 patients were alive without disease, and 1 patient died of unrelated disease without recurrence. All patients who died of the disease had developed distant metastasis. Based on univariate analysis, tumor grade (high grade) and lymph node metastases (≥N2) were significant prognostic factors for OS and LRC. It also revealed tumor grade (high grade), T classification (≥T3), and lymph node metastases (≥N2) were significant for distant metastasis. Multivariate analysis showed the following significant prognostic factors: lymph node metastases (≥N2) for OS, LRC, and NDM, and high tumor grade for NDM., Conclusion: Our study suggested death of submandibular gland carcinoma occurred mainly due to distant metastasis. The significant predictors of distant metastasis were lymph node metastases (≥N2) and tumor grade (high grade)., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives/hypothesis: Endoscopic laryngopharyngeal surgery (ELPS), a hybrid of head and neck surgery and gastrointestinal endoscopic treatment, has been attracting attention as a new therapeutic modality for superficial laryngopharyngeal cancers. Although this technique is less invasive than traditional open procedures, some complications including postoperative bleeding, subcutaneous emphysema, or aspiration pneumonia can occur after treatment. The purpose of this study was to investigate the complications associated with ELPS to better understand the indications for this procedure., Study Design: Retrospective medical chart review., Methods: One hundred five patients with 159 laryngeal or pharyngeal lesions were treated with ELPS between August 2009 and September 2015 at Kyoto University Hospital. In total, 147 resections were performed, and complications after the resections were reviewed., Results: Of the 147 resections, postoperative bleeding, subcutaneous emphysema, and aspiration pneumonia were observed in 10, 17, and 10 cases, respectively. All cases with postoperative bleeding and aspiration pneumonia occurred in patients over 65 years of age. A history of taking anticoagulation/platelet medications, and macroscopic 0-IIa lesions were shown to correlate with postoperative bleeding after ELPS. Resection of lesions in the pyriform sinus was found to be associated with subcutaneous emphysema., Conclusions: All complications after ELPS were safely managed. A history of taking anticoagulation/platelet medications and macroscopic 0-IIa lesions were identified as risk factors for postoperative bleeding, whereas resection of pyriform sinus lesions was found to be a risk factor for subcutaneous emphysema. These risk factors should be carefully considered when treating pharyngeal and laryngeal lesions by ELPS., Level of Evidence: 4. Laryngoscope, 128:1546-1550, 2018., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives: The management of patients with cervical metastasis in head and neck cancer of unknown primary (HNCUP) remains controversial. This current multicenter retrospective study investigated the treatment outcomes of patients with HNCUP., Methods: The study included patients who were treated curatively at 12 institutions in Japan from January 2006 to December 2015., Results: Eighty patients with HNCUP were included. The median follow-up period was 34 months. The three-year overall survival (OS), disease-specific survival (DSS), regional relapse-free survival (RRFS), local progression-free survival (LPFS), and distant metastasis-free survival (DMFS) rates were 72.5%, 80.3%, 74.0%, 89.7%, and 86.9%, respectively. Nodal status was a significant factor for OS, DSS, RRFS, and DMFS; and extracapsular extension (ECE) was significant for OS and DSS. There was a distinct difference between the survival rates of patients with N1-2a and N2b-3 disease. RT was a significant positive factor for LPFS (3-year LPFS, RT 93.0% vs. no RT 83.0%, p = .043)., Conclusions: For N2a as well as N1 disease without ECE, a single treatment modality, including ND or RT alone is acceptable. When ND alone is performed, thorough monitoring should be continued during follow-up to identify the emergence of the primary lesion.

Objectives/hypothesis: The vocal fold epithelium that includes tight junction (TJ)-based barrier function protects underlying connective tissues from external insults. TJs play an important role to control paracellular permeability of not only solutes but also ions, and preserve the vocal fold homeostasis. However, the distribution of TJs and paracellular diffusion barrier across the entire vocal fold epithelium are still unknown. The aim of this study was to identify the distribution of TJs in the vocal fold epithelium and to characterize the recovery process of TJ-based paracellular diffusion barrier in a rat model of vocal fold injury., Study Design: Animal experiments with controls., Methods: Normal and vocal fold-injured rats were used. Larynges were harvested for immunohistochemical examination of TJ proteins. For functional analysis, a tracer permeability assay was performed using EZ-Link Sulfo-NHS-LC-Biotin., Results: TJ proteins occludin and zonula occludens 1 signals were localized to the junctional regions of the most luminal cell layers of the vocal fold epithelium. The injured region had been recovered with epithelium at 5 days postinjury, but the paracellular diffusion barrier assays revealed that biotinylation reagents diffused into the lamina propria at 5 days postinjury, and were blocked at the epithelium at 14 and 28 days postinjury., Conclusions: It was strongly suggested that TJs in the vocal fold epithelium exist at the junctional regions of the first layer of stratified squamous epithelium. TJ-based paracellular diffusion barrier following vocal fold injury is recovered by 14 days postinjury, and this period corresponds with the time course of structural changes in the regenerating epithelium layer., Level of Evidence: NA. Laryngoscope, 128:E150-E156, 2018., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Vocal fold scar and sulcus are intractable diseases with no effective established treatments. Hepatocyte growth factor (HGF) has preclinically proven to have potent antifibrotic and regenerative effects on vocal fold scar. The current Phase I/II clinical trial aims to examine the safety and effectiveness of intracordal injection of a recombinant human HGF drug for patients with vocal fold scar or sulcus. This is an open-label, dose-escalating, first-in-human clinical trial. Eighteen patients with bilateral vocal fold scar or sulcus were enrolled and divided into three groups: Step I received 1 μg of HGF per vocal fold; Step II received 3 μg of HGF; and Step III received 10 μg of HGF. Injections were administered once weekly for 4 weeks. The protocol treatment was performed starting with Step I and escalating to Step III. Patients were followed for 6 months post-treatment. Local and systemic safety aspects were examined as primary endpoints, and therapeutic effects were assessed as secondary endpoints using voice handicap index-10; maximum phonation time; vocal fold vibratory amplitude; grade, rough, breathy, asthenic, strained scale; and jitter. The results indicated no serious drug-related adverse events in either the systemic or local examinations. In whole-subject analysis, voice handicap index-10, vocal fold vibratory amplitude, and grade, rough, breathy, asthenic, strained scale were significantly improved at 6 months, whereas maximum phonation time and jitter varied. There were no significant differences in phonatory data between the step groups. In conclusion, intracordal injection of a recombinant human HGF drug was safe, feasible, and potentially effective for human patients with vocal fold scar or sulcus., (Copyright © 2017 John Wiley & Sons, Ltd.)

Background: Planar cell polarity (PCP) coordinates the patterning and orientation of cells and their structures along tissue planes, and although its acquisition during the formation of airway epithelium has been described, the mechanisms for its maintenance and reconstruction are poorly understood. We aimed to clarify whether ambient environment change by orthotropic autologous transplantation affected PCP at the cellular level., Methods: We performed orthotropic autologous transplantation by inverting tracheal segments in rats, and then performed morphological evaluation by microscopy. The PCP of the tracheal epithelium was assessed over time by analyzing the directions of mucociliary transport and ciliary beat, the positional relationship between the basal body and basal foot, and the bias of Vang-like protein 1 (Vangl1) at 2, 4, and 6 months postoperatively., Results: After 2 months, the directions of mucociliary transport and ciliary beat were preserved toward the lung in the inverted tracheal segments. The positional relationship between the basal body and the basal foot, and the bias of Vangl1, also indicated preservation of PCP in the inverted tracheal segments. Similar results were obtained at 6 months., Conclusion: The PCP of ciliated epithelium was preserved in reversed trachea, even after long-term observation.

Background: The purpose of this cadaveric study was to determine the efficacy of a flexible, next-generation robotic surgical system for transoral robotic hypopharyngectomy., Methods: A comparative evaluation study of the flexible versus rigid robotic surgical systems for the hypopharynx was conducted using 3 cadavers. Endpoints for assessment were visualization of the hypopharynx, access to the hypopharynx, and difficulty of dissection. Hypopharyngectomy was performed on 3 other cadavers using the da Vinci Sp surgical system., Results: Access to the apex of the pyriform sinus and the esophageal inlet was easier with the da Vinci Sp than with the da Vinci Si. Dissection with the da Vinci Sp was easier in all areas of the hypopharynx than with the da Vinci Si. Robotic hypopharyngectomy was successfully completed on all cadavers using the da Vinci Sp surgical system., Conclusion: Preclinical testing in human cadavers suggests that flexible robotic surgery may facilitate successful transoral hypopharyngectomy., (© 2017 Wiley Periodicals, Inc.)

Objectives/hypothesis: This study aimed to reveal the effects of adipose-derived mesenchymal stromal cells (ASCs) on prevention of vocal fold scarring by investigating how the immediate ASCs transplantation into the injured rat vocal fold affect the levels of gene transcription and translation., Study Design: Prospective animal experiments with controls., Methods: ASCs harvested from green fluorescent protein transgenic rat (ASCs group) or saline (sham group) were injected into the thyroarytenoid muscle of Sprague-Dawley rats immediately after stripping the vocal fold. For histological examinations, larynges were extirpated at 3, 14, and 56 days after the injection. Quantitative real-time polymerase chain reaction (PCR) analyses were performed at 3 and 14 days after the injection., Results: Transplanted ASCs were detected only in larynges at day 3. At days 14 and 56, histological examination showed significantly higher amounts of hyaluronic acid and lower deposition of collagen in the ASCs group compared to the sham group. Real-time PCR revealed that the ASCs group showed low expression of procollagen (Col)1a1, Col1a3, matrix metalloproteinase (Mmp)1 and Mmp8 in each time points. The ASCs group showed high expression of fibroblast growth factor (Fgf)2 and Hepatocyte growth factor (Hgf) compared to the sham group at day 14., Conclusions: ASCs increased expressions of Fgf2 and Hgf, and suppressed excessive collagen deposition during vocal fold wound healing. Given the fact that ASCs survived no more than 14 days, ASCs were thought to induce upregulations of growth factors' genes in surrounding cells. These results suggested that ASCs have potential to prevent vocal fold scarring., Level of Evidence: NA. Laryngoscope, 128:E33-E40, 2018., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Adenoid cystic carcinoma of the head and neck (ACCHN) is rare and difficult to study effective treatment at one institute. Our aim is to identify prognostic factors for this disease by conducting a multicenter study at 11 institutions in Japan., Methods: A retrospective multicenter study of ACCHN was performed. One hundred and three patients were identified between 2006 and 2015. The overall survival (OS) rate for all patients was calculated, and OS, locoregional control (LRC) rate, or no distant metastasis (NDM) rate was calculated for patients in that the surgery was performed without distant metastasis (DM). Statistical analyses were performed., Results: A significant difference with multivariate analysis was observed in patients in sublingual glands, stage IV and the use of radiation therapy ≥60Gy (sufficient RT) in OS for all patients. A significant difference was observed in the use of sufficient postoperative RT in the OS and the LRC rate, and in pathological surgical margins in the NDM rate., Conclusion: Sublingual glands or stage IV was a poorer, and sufficient RT was a better prognostic factor for ACCHN. Sufficient RT was effective to prevent local recurrence after surgical resection. Positive surgical margins caused an increase in DM.

Background: Parotid gland carcinoma is a rare malignancy, comprising only 1-4% of head and neck carcinomas; therefore, it is difficult for a single institution to perform meaningful analysis on its clinical characteristics. The aim of this study was to update the clinical knowledge of this rare disease by a multi-center approach., Methods: The study was conducted by the Kyoto University Hospital and Affiliated Facilities Head and Neck Clinical Oncology Group (Kyoto-HNOG). A total of 195 patients with parotid gland carcinoma who had been surgically treated with curative intent between 2006 and 2015 were retrospectively reviewed. Clinical results including overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), local control rate (LCR), regional control rate (RCR), and distant metastasis-free survival (DMFS) were estimated. Univariate and multivariate analyses were performed to identify prognostic factors., Results: The median patient age was 63years old (range 9-93years), and the median observation period was 39months. The OS, DFS, DSS, LCR, RCR, and DMFS at 3years were 85%, 74%, 89%, 92%, 88%, and 87%, respectively. Univariate analysis showed age over 74, T4, N+, preoperative facial palsy, high grade histology, perineural invasion, and vascular invasion were associated with poor OS. N+ and high grade histology were independent factors in multivariate analysis. In subgroup analysis, postoperative radiotherapy was associated with better OS in high risk patients., Conclusion: Nodal metastases and high grade histology are important negative prognostic factors for OS. Postoperative radiotherapy is recommended in patients with advanced high grade carcinoma., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Although tracheal invasion from thyroid cancer is life-threatening, the epidemiology of its development remains unclear. This study aimed to determine the epidemiology (prevalence, incidence, and risk factors) and functional outcomes of tracheal invasion from thyroid cancer among Japanese patients who were eligible for full-layer tracheal resection., Methods: Patients with thyroid cancer and with or without tracheal invasion were identified based on procedure codes using a large inpatient database that is maintained by a data vendor. The prevalence and incidence were estimated for each age and sex using Japanese volume of thyroidectomies and Japanese population data. We also explored whether a tumor-related tracheal defect was successfully reconstructed after full-layer tracheal resection., Results: Among the 8482 patients with thyroid cancer, the overall prevalence of tracheal invasion was 0.4-0.7%. The overall incidence of thyroid cancer was 12.0/100,000 persons, and the incidence of tracheal invasion was estimated to be 0.05-0.09/100,000 persons. The age distributions were noticeably different between thyroid cancer cases with and without tracheal invasion. The highest incidence was observed at ages of 70-79 years for thyroid cancer with tracheal invasion and 60-69 years for thyroid cancer without invasion. Approximately one-half of patients experienced long-term use of a tracheal tube and/or multiple operations for tracheal reconstruction., Conclusion: The peak incidence of tracheal invasion from thyroid cancer was observed at ages of >70years. In addition, conventional surgical management appears to be limited in its ability to reconstruct tracheal defects., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objectives: Professional voice users, such as singers and teachers, are at greater risk of developing vocal fold injury from excessive use of voice; thus, protection of the vocal fold is essential. One of the most important factors that aggravates injury is the production of reactive oxygen species at the wound site. The purpose of the current study was to assess the effect of astaxanthin, a strong antioxidant, on the protection of the vocal fold from injury and inflammation due to vocal loading., Study Design: This study is an institutional review board-approved human clinical trial., Methods: Ten male subjects underwent a 60-minute vocal loading session and received vocal assessments prior to, immediately after, and 30 minutes postvocal loading (AST(-) status). All subjects were then prescribed 24 mg/day of astaxanthin for 28 days, after which they received the same vocal task and assessments (AST(+) status). Phonatory parameters were compared between both groups., Results: Aerodynamic assessment, acoustic analysis, and GRBAS scale (grade, roughness, breathiness, asthenia, and strain) were significantly worse in the AST(-) status immediately after vocal loading, but improved by 30 minutes after loading. In contrast, none of the phonatory parameters in the AST(+) status were statistically worse, even when measured immediately after vocal loading. No allergic responses or adverse effects were observed after administration of astaxanthin., Conclusions: The current results suggest that astaxanthin can protect the vocal fold from injury and inflammation caused by vocal loading possibly through the regulation of oxidative stress., (Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)