Complications including dysphagia following transoral non-robotic surgery for pharyngeal and laryngeal squamous cell carcinoma: A retrospective multicenter study

OBJECTIVE

Transoral surgery is a minimally invasive treatment but may cause severe dysphagia at a lower rate than chemoradiotherapy.

METHODS

We compared clinical information, surgical complications, and swallowing function in patients who underwent transoral nonrobotic surgery for laryngo-pharyngeal squamous cell carcinoma between 2015 and 2021 in a multicenter retrospective study.

RESULTS

Six hundred and forty patients were included. Postoperative bleeding was observed in 20 cases (3.1%), and the risk factor was advanced T category. Postoperative laryngeal edema was observed in 13 cases (2.0%), and the risk factors were prior radiotherapy, advanced T stage, and concurrent neck dissection in patients with resected HPC. Dysphagia requiring nutritional support was observed in 29 cases (4.5%) at 1 month postoperatively and in 19 cases (3.0%) at 1 year postoperatively, respectively. The risk factors for long-term dysphagia were prior radiotherapy and advanced T category. Short-term risk factors for dysphagia were prior radiotherapy, advanced T category, and concurrent neck dissection, while long-term risk factors for dysphagia were only prior radiotherapy and advanced T category.

CONCLUSION

Prior radiotherapy, advanced T stage, and concurrent neck dissection increased the incidence of postoperative laryngeal edema and short-term dysphagia, but concurrent neck dissection did not affect long-term dysphagia. Such features should be considered when considering the indication for transoral surgery and postoperative management.

Objective Assessment of Pathological Voice Using Artificial Intelligence Based on the GRBAS Scale

OBJECTIVES

The validity and reliability of the psychological assessment of auditory perceptions, as typified by the grade, roughness, breathiness, asthenia, and strain (GRBAS) scale, have been widely recognized. However, due to their subjective nature, inter- and intra-examiner reliability are unavoidable. In this study, we aimed to add objectivity to the GRBAS scale using artificial intelligence and to compare the accuracy of two methods-one based on Google's TensorFlow and another based on Apple's Core ML.

METHODS

The GRBAS scale of 1,377 vowel samples was evaluated and used as training data to create a machine learning model. We used TensorFlow and Apple's Create ML to create two machine learning models and examined the difference in their accuracies for classifying the severity of pathological Voice data based on the GRBAS scale.

RESULTS

Absolute comparisons are difficult to make because of the difference in methods; however, both training models could objectively evaluate GRBAS scales and were statistically correlated in G and B.

CONCLUSION

While TensorFlow requires creation of a training model from scratch, Create ML is a relatively easy way to create a training model for voice by adding training data for GRBAS scales to an existing training model for sounds. Although the data handling and learning methods are different, both models performed well. Findings from this study could be used for medical screening purposes, and there is the potential to change the clinical approach to voice diagnostics in the future.

Interactive effects of hearing aid use and cognitive function in patients with hearing loss

BACKGROUND

There has been a significant increase in scientific investigations of the hearing-dementia association among the research on potentially modifiable risk factors for cognitive impairment. We tested two clinical questions. Analysis 1: does persistent hearing aid (HA) use decrease the decline in cognitive function caused by ageing? Analysis 2: does cognitive function at the time of HA fitting predict future persistent HA use?

METHODS

This case-control study performed at two referral centres reported data obtained over a 4.5-year period. We recruited a group of patients with cognitive decline, aged 65 or older with or without hearing loss. The intervention consisted of the use of HAs. The primary outcome measures were adherence to continuous HA use and cognitive function measured using the Japanese version of the Mini-Mental State Examination Test and the Reading Cognitive Test Kyoto.

RESULTS

Eighteen HA users and 18 controls were included in the first analysis. HA use was associated with a deceleration of cognitive decline 12 months later. In the second analysis, 11 participants with good adherence to HA use were compared with 12 participants who showed poor adherence to HA use. Among the variables employed in this study, cognitive function measured using the Reading Cognitive Test Kyoto was significantly lower in participants with poor adherence to HA.

CONCLUSIONS

HA use in cognitively impaired individuals with hearing loss can slow age-related cognitive decline. Cognitively impaired people with hearing loss who fail to commit to HA use tend to have lower cognitive measurement scores before HA fitting. HA use is generally more challenging as people age and their cognitive abilities decline. Therefore, it is desirable that HAs be used when hearing loss and dementia are in their early stages.

Anatomical variations in the superficial venous system of the neck: an image-based study using contrast-enhanced computed tomography

PURPOSE

The superficial venous system (SVS) of the neck receives blood from the face and oral cavity. The SVS comprises the anterior jugular vein (AJV), external jugular vein (EJV), and facial vein (FV). Comprehensive knowledge of the normal anatomy and potential variations in the venous system is valuable in surgical and radiological procedures. This study aimed to update the anatomic knowledge of the SVS using a radiographic approach, which is a beneficial data source in clinical practice.

METHODS

Contrast-enhanced computed tomography images of the neck of patients with head and neck cancer treated between 2017 and 2020 were retrospectively evaluated. Each side of the neck was counted separately. A total of 302 necks of 151 patients were enrolled in this study.

RESULTS

The medial AJV was absent in 49.7% (75/151) of the patients on the left side, which was significantly greater than the 19.2% (29/151) on the right (p < 0.001). The left AJV drained into the right venous system in 6.6% (10/151) of the necks. In 48.3% (146/302) of the necks, the FV did not flow into the internal jugular vein but rather into the EJV or AJV; these findings were significantly more frequent than those reported in previous studies. The diameters of the veins were significantly larger when they received blood from the FV than when they were not connected to the FV.

CONCLUSION

These findings indicate that the AJV has a rightward preference during its course. The course of the FV is diverse and affects the diameter of connected veins.

Effects of high-dose betahistine on intractable dizziness in patients with uncompensated unilateral vestibulopathy

OBJECTIVE

In the present study, we examined the effects of high-dose betahistine on dizziness handicap inventory (DHI) scores in patients with unilateral vestibulopathy.

METHODS

An uncontrolled, open-label, multicenter clinical trial was conducted. Fifteen patients with unilateral vestibulopathy, such as vestibular neuritis, who complained of intractable dizziness for more than three months were enrolled. Initially, all patients were orally administered betahistine at a dose of 36 mg/day for four weeks, which is the standard dose and dosing period for the treatment of dizziness in Japan. The patients were then administered betahistine at a double dose of 72 mg/day for four weeks. Six patients who became aware of the benefits of high-dose betahistine were further administered betahistine at 72 mg/day for an additional 12 weeks (a total of 16 weeks). Perceived disability due to dizziness was assessed by DHI scores.

RESULTS

In all 15 patients, short-term administration with high-dose (72 mg/day) betahistine for four weeks, but not low-dose betahistine (36 mg/day) for four weeks significantly decreased DHI scores. In particular, in six responding patients with self-reported benefits after short-term administration with high-dose betahistine, long-term administration with high-dose betahistine for 16 weeks further significantly decreased DHI scores. However, DHI scores of the remaining nine non-responding patients were not changed after short-term administration with high-dose betahistine for four weeks.

CONCLUSION

Short-term administration with the standard dose and dosing period of betahistine did not improve DHI scores in the enrolled patients, indicating that they were not compensated for unilateral vestibulopathy with intractable dizziness. The present findings suggest that long-term administration with high-dose betahistine facilitates vestibular compensation to improve intractable dizziness in some, but not all patients with uncompensated unilateral vestibulopathy.

Utility of Diffusion-weighted MR Imaging for Evaluating the Depth of Invasion in Oral Tongue Squamous Cell Carcinoma

PURPOSE

The 8th edition of the American Joint Committee on Cancer staging system included the depth of invasion (DOI) for the T classification of oral cancer. However, no standardized method has been established to clinically measure the DOI. This study aimed to investigate the accuracy of MRI-based DOI for oral tongue squamous cell carcinoma (OTSCC) in each MRI sequence.

METHODS

We enrolled 49 patients with histologically proven OTSCC, treated surgically between April 2017 and February 2021. We divided the DOI into three groups using 5 and 10 mm, the thresholds for determining the T stage, and retrospectively evaluated the agreement between MRI-based DOI and pathological DOI (pDOI) for each MRI sequence, axial T1-weighted imaging (T1WI), T2-weighted imaging with fat suppression (FS-T2WI), contrast-enhanced T1WI with fat suppression (CE-T1WI), diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) maps. We also divided the DOI into two groups using 3 mm, the threshold for considering elective neck dissection, and evaluated the overestimation rate of MRI-based DOI in lesions with pDOI ≤ 3 mm.

RESULTS

With 5-mm and 10-mm divisions, the accuracy of the DOI assessment was highest on DWI (0.82, weighted kappa = 0.85). With a 3-mm division, the accuracy was also highest on DWI (0.87, kappa = 0.73). The overestimation rate of the MRI-based DOI in lesions with pDOI ≤ 3 mm was lowest on DWI (27.8%).

CONCLUSION

DOI on DWI exhibits a comparatively higher rate of concordance with pDOI. DWI may be more useful than other MRI sequences in evaluating the DOI of OTSCC.

EBF1 Limits the Numbers of Cochlear Hair and Supporting Cells and Forms the Scala Tympani and Spiral Limbus during Inner Ear Development

Early B-cell factor 1 (EBF1) is a basic helix-loop-helix transcription factor essential for the differentiation of various tissues. Our single-cell RNA sequencing data suggest that Ebf1 is expressed in the sensory epithelium of the mouse inner ear. Here, we found that the murine Ebf1 gene and its protein are expressed in the prosensory domain of the inner ear, medial region of the cochlear duct floor, otic mesenchyme, and cochleovestibular ganglion. Ebf1 deletion in mice results in incomplete formation of the spiral limbus and scala tympani, increased number of cells in the organ of Corti and Kölliker's organ, and aberrant course of the spiral ganglion axons. Ebf1 deletion in the mouse cochlear epithelia caused the proliferation of SOX2-positive cochlear cells at E13.5, indicating that EBF1 suppresses the proliferation of the prosensory domain and cells of Kölliker's organ to facilitate the development of appropriate numbers of hair and supporting cells. Furthermore, mice with deletion of cochlear epithelium-specific Ebf1 showed poor postnatal hearing function. Our results suggest that Ebf1 is essential for normal auditory function in mammals.

Diagnostic and therapeutic strategies for vestibular neuritis of the Japan Society for Equilibrium Research

OBJECTIVE

To provide diagnostic and therapeutic strategies for vestibular neuritis in accordance with the Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021.

METHODS

The Committee for Clinical Practice Guidelines for Vestibular Neuritis was entrusted with a review of the relevant scientific literature on the above topic. Clinical Questions (CQs) concerning the treatment of vestibular neuritis were produced, and a search of the literature was conducted to identify studies related to the CQs. The recommendations were based on the literature review and the expert opinion of a subcommittee.

RESULTS

We proposed the diagnostic criteria for vestibular neuritis, as well as answers to CQs, recommendations, and evidence levels for the treatment of vestibular neuritis.

CONCLUSION

The diagnostic criteria for vestibular neuritis were based on clinical history and examination findings after completing the differential diagnosis process. The treatment of vestibular neuritis was divided into acute, subacute, and chronic stages. The Japanese Clinical Practice Guidelines for Vestibular Neuritis 2021 should be used as a reference in the diagnosis and treatment of vestibular neuritis.

A multi-institutional retrospective study of 340 cases of sinonasal malignant tumor

OBJECTIVE

Sinonasal malignant tumors (SNMT) are relatively rare among head and neck malignant tumors. Most are squamous cell carcinomas, and malignant melanomas, olfactory neuroblastomas, adenoid cystic carcinomas, sarcomas, and others also occur. The most common primary site of nasal sinus squamous cell carcinoma is the maxillary sinus. In recent years, a decrease in incidence of maxillary sinus squamous cell carcinoma (MSSCC) has been reported along with a decrease in the incidence of sinusitis. MSSCC is treated with a combination of surgery, radiation, and chemotherapy. Treatment decisions are made according to the progression of the disease, the patient's general condition, and the patient's own wishes. There are variations in treatment policies among facilities due to the specialty of staff and cooperation with other departments at each facility. We conducted a multi-institutional retrospective study to compare outcomes by treatment strategy.

METHODS

In this study, 340 patients with SNMT who were treated at 13 Hospitals (Head and Neck Oncology Group (Kyoto-HNOG) ) during the 12-year period from January 2006 to December 2017 were included. There were 220 patients with squamous cell carcinoma, 32 with malignant melanoma, 21 with olfactory neuroblastoma, and 67 with other malignancies. Of the squamous cell carcinomas, 164 were of maxillary sinus origin. One hundred and forty cases of MSSCC that were treated radically were included in the detailed statistical analysis.

RESULTS

There were 5 cases of cStage I, 9 cases of cStage II, 36 cases of cStage III, 74 cases of cStage IVa, and 16 cases of cStage IVb. There were 92 cases without clinical lymph node metastasis (cN(-)) and 48 cases with clinical lymph node metastasis(cN(+)). Primary tumors were treated mainly by surgery in 85 cases (Surg) and by radical radiation therapy (with or without chemotherapy) of 6-70 Gy in 55 cases(non-Surg). The 5-year overall/disease-free survival rate (OS/DFS) for MSSCC was 65.1%/51.6%. Old age, renal dysfunction, and clinical T progression were independent risk factors for OS, and renal dysfunction was an independent risk factor for DFS. In cN(-) patients, OS and DFS were significantly better in Surg group than in non-Surg group. In cN(+) patients, there was no significant difference in OS and DFS between Surg and non-Surg groups.

CONCLUSION

For patients with MSSCC without lymph node metastasis, aggressive surgery on the primary tumor contributes to improved prognosis.

Comparative Study of Immunodeficient Rat Strains in Engraftment of Human-Induced Pluripotent Stem Cell-Derived Airway Epithelia

The airway epithelia (AE) play a role in the clearance of foreign substances through ciliary motility and mucus secreted. We developed an artificial trachea that is made of collagen sponges and polypropylene mesh for the regeneration of the tracheal defect, and it was used for a clinical study. Then, a model in which the luminal surface of an artificial trachea was covered with a human-induced pluripotent stem cell-derived AE (hiPSC-AE) was transplanted into the tracheal defect of nude rats to promote epithelialization. In the future, this model was expected to be applied to research on infectious diseases and drug discovery as a trachea-humanized rat model. However, at present, sufficient engraftment has not been achieved to evaluate functional recovery in transplanted cells. Therefore, this study focused on immunosuppression in recipient rats. Nude rats lack T cell function and are widely used for transplantation experiments; however, more severe immunosuppressed recipients are preferred for xenotransplantation. Several strains of immunodeficient rats were created as rats that exhibit more severe immunodeficiency until now. In this study, to establish a trachea-humanized rat model in which human AE function can be analyzed to improve engraftment efficiency, engraftment efficiency in nude rats and X-linked severe combined immunodeficiency (X-SCID) rats following hiPSC-AE transplantation was compared. In the analysis of the proportion of engrafted cells in total cells at the graft site, the engraftment efficiency of epithelial cells tended to be high in X-SCID rats, although no statistical difference was found between the two groups, whereas the engraftment efficiency of mesenchymal cells was higher in X-SCID rats. Furthermore, the number of immune cells that accumulated in the grafts showed that a pan T cell marker, that is, CD3-positive cells, did not differ between the two strains; however, CD45-positive cells and major histocompatibility complex (MHC) class II-positive cells significantly decreased in X-SCID rats. These results indicate that X-SCID rats are more useful for the transplantation of hiPSC-AE into the tracheae to generate trachea-humanized rat models.

Long-term effects of second cochlear implantation with sequential bilateral cochlear implantation in Japanese children

OBJECTIVE

This study aimed to longitudinally evaluate speech perception ability and sound-field thresholds with the first, second, or bilateral cochlear implants (CIs) and MAP parameters of second CI in children.

METHODS

Eighteen children who underwent bilateral cochlear implantation at Kyoto University Hospital were included. We evaluated speech perception under quiet and noisy conditions using the first, second, or bilateral CIs, CI-aided sound-field thresholds using the first or second CI, and MAP parameter values (C-levels, T-levels, and dynamic range) of the second CI of more than 5 years after the second implantation.

RESULTS

Patients with a second CI after 7 years of age had significantly worse speech perception ability with the second CI even long after the surgery than those with a second CI before 7 years of age. CI-aided sound-field thresholds using the first or second CI were similar, regardless of the second implantation timing. Speech perception in noise with bilateral CIs was enhanced by the addition of a second CI, even after 7 years of age. Patients undergoing second cochlear implantation before 3.5 years of age showed significantly higher C-levels and wider dynamic ranges in the second CI MAP parameters.

CONCLUSIONS

When the second implantation was performed after 7 years of age, the second CI effects were limited even with long-term use, which is attributed to unstable MAP parameters. The second CI-aided sound-field threshold contributed to the better outcome of bilateral CIs in noise, even if the second implantation was performed at age of ≥7 years.

Pharmacokinetics of monoclonal antibodies locally-applied into the middle ear of guinea pigs

Countless therapeutic antibodies are currently available for the treatment of a broad range of diseases. Some target molecules of therapeutic antibodies are involved in the pathogenesis of sensorineural hearing loss (SNHL), suggesting that SNHL may be a novel target for monoclonal antibody (mAb) therapy. When considering mAb therapy for SNHL, understanding of the pharmacokinetics of mAbs after local application into the middle ear is crucial. To reveal the fundamental characteristics of mAb pharmacokinetics following local application into the middle ear of guinea pigs, we performed pharmacokinetic analyses of mouse monoclonal antibodies to FLAG-tag (FLAG-mAbs), which have no specific binding sites in the middle and inner ear. FLAG-mAbs were rapidly transferred from the middle ear to the cochlear fluid, indicating high permeability of the round window membrane to mAbs. FLAG-mAbs were eliminated from the cochlear fluid 3 h after application, similar to small molecules. Whole-body autoradiography and quantitative assessments of cerebrospinal fluid and serum demonstrated that the biodistribution of FLAG-mAbs was limited to the middle and inner ear. Altogether, the pharmacokinetics of mAbs are similar to those of small molecules when locally applied into the middle ear, suggesting the necessity of drug delivery systems for appropriate mAb delivery to the cochlear fluid after local application into the middle ear.

Impact of cervical lymph node metastasis on transoral surgery for hypopharyngeal squamous cell carcinoma: A retrospective multicenter study

BACKGROUND

Hypopharyngeal carcinoma is likely to spread to the lymph nodes, but there is no established strategy for management in transoral surgery.

METHODS

We compared oncologic and functional outcomes in a retrospective multicenter study of patients who underwent transoral surgery for hypopharyngeal carcinoma between 2015 and 2021.

RESULTS

Two-hundred and thirty-two patients were included. Comparing patients with and without adjuvant radiotherapy, 3-year regional recurrence-free survival (RRFS) was not significantly different in pN2b and pN2c, but was significantly worse in pN3b without adjuvant radiotherapy. In patients without neck dissection, the 3-year RRFS was 85.6%, 76.8%, and 70.0% for T1, T2, and T3 primary lesions, respectively, and was significantly worse for T2 or higher (p = 0.035).

CONCLUSIONS

In the absence of extracapsular invasion, regional control did not deteriorate without adjuvant therapy. If prophylactic neck dissection is not performed, careful follow-up is necessary if the primary lesion is T2 or greater.

The Effect of Noise on Deep Learning for Classification of Pathological Voice

OBJECTIVE

This study aimed to evaluate the significance of background noise in machine learning models assessing the GRBAS scale for voice disorders.

METHODS

A dataset of 1406 voice samples was collected from retrospective data, and a 5-layer 1D convolutional neural network (CNN) model was constructed using TensorFlow. The dataset was divided into training, validation, and test data. Gaussian noise was added to test samples at various intensities to assess the model's noise resilience. The model's performance was evaluated using accuracy, F1 score, and quadratic weighted Cohen's kappa score.

RESULTS

The model's performance on the GRBAS scale generally declined with increasing noise intensities. For the G scale, accuracy dropped from 70.9% (original) to 8.5% (at the highest noise), F1 score from 69.2% to 1.3%, and Cohen's kappa from 0.679 to 0.0. Similar declines were observed for the remaining RBAS components.

CONCLUSION

The model's performance was affected by background noise, with substantial decreases in evaluation metrics as noise levels intensified. Future research should explore noise-tolerant techniques, such as data augmentation, to improve the model's noise resilience in real-world settings.

LEVEL OF EVIDENCE

This study evaluates a machine learning model using a single dataset without comparative controls. Given its non-comparative design and specific focus, it aligns with Level 4 evidence (Case-series) under the 2011 OCEBM guidelines Laryngoscope, 2024.

Local recurrence and metachronous multiple cancers after transoral nonrobotic surgery for pharyngeal and laryngeal squamous cell carcinoma: A retrospective multicenter study

BACKGROUND

Late laryngopharyngeal cancers after transoral surgery include not only local recurrences but also metachronous multiple cancers.

METHODS

We compared clinical information, surgical outcomes, and late laryngopharyngeal cancers in patients who underwent transoral nonrobotic surgery for laryngopharyngeal squamous cell carcinoma without lymph node metastases between 2015 and 2021 in a multicenter retrospective study.

RESULTS

Four hundred and fifty-seven patients were included. Positive surgical margins were found in 121 patients (26.5%). Twenty-two patients (4.8%) received additional treatment. Positive horizontal margins of invasive carcinoma (p = 0.003) and positive horizontal margins of carcinoma in situ only (p = 0.032) were independent risk factors for local recurrence, and prior radiotherapy (p = 0.001) for metachronous multiple cancers. Local control was significantly worse without additional treatment (p = 0.049), but there was no significant difference in survival.

CONCLUSIONS

Patients with positive margins had an increased frequency of local recurrence, but salvage therapy was effective.

Mucosal melanoma of the head and neck: a retrospective analysis of 34 cases in Japan

PURPOSE

Mucosal melanoma of the head and neck (MMHN) is a rare condition. This study aimed to investigate oncological outcomes of surgical intervention in patients with MMHN.

MATERIALS AND METHODS

The study included 34 patients with MMHN who underwent surgical resection as initial treatment at 10 institutions in Japan between July 2005 and June 2015. Results: The 5-year overall survival (OS), local control rate (LCR), disease-free survival (DFS), and disease-specific survival (DSS) rates were 48.7%, 53.4%, 32.4%, and 55.1%, respectively. Based on multivariate analysis, no independent prognostic factors for the 5-year OS and DSS were found. Based on univariate analysis, the 5-year LCR was worse in patients with lesions in the nasal cavity and paranasal sinuses than in the oral cavity and pharynx. However, no differences in oncological outcomes were identified in relation to primary sites, and postoperative radiotherapy (PORT) and adjuvant systemic therapy did not contribute to improvements in the 5-year OS.

CONCLUSIONS

No independent prognostic factors for the 5-year OS or DSS were identified. Regional or distant recurrences are often identified, regardless of local control with surgical resection. Difficult control of MMHN with conventional therapeutic strategies, such as surgical intervention, PORT, and systemic therapy, has been suggested.

Changes in the Proportion of Each Cell Type After hiPSC-Derived Airway Epithelia Transplantation

No radical treatment is available for the regeneration of dysfunction and defects in airway epithelia. Artificial tracheae made of polypropylene and collagen sponge were used in clinical studies to reconstitute tracheae after resection. For early epithelialization of the luminal surface of the artificial trachea, a model was established, that is, an artificial trachea covered with human-induced pluripotent stem cell-derived airway epithelial cells (hiPSC-AECs) was transplanted into a tracheal defect in an immunodeficient rat. Unlike the cell types of hiPSC-derived cells that are currently used in clinical studies, AECs maintain tissues by proliferation and differentiation of basal cells into various cell types that constitute AECs constantly. Therefore, post-transplantation, the proportion of each cell type, such as ciliated and goblet cells, may change; however, no studies have examined this possibility. In this study, using our hiPSC-AEC-transplanted rat model, we investigated changes in the proportion of each cell type in hiPSC-AECs pre-transplantation and post-transplantation. As a result, the proportion of each cell type changed post-transplantation. The proportion of ciliated, basal, and club cells increased, and the proportion of goblet cells decreased post-transplantation. In addition, the proportion of each cell type in engrafted hiPSC-AECs is more similar to the proportion of each cell type in normal proximal airway tissue than the proportion of each cell type pre-transplantation. The results of this study are useful for the development of therapeutic techniques using hiPSC-AEC transplantation.

The combination of soluble forms of PD-1 and PD-L1 as a predictive marker of PD-1 blockade in patients with advanced cancers: a multicenter retrospective study

Introduction

The clinical relevance of soluble forms of programmed cell death-1 (sPD-1) and programmed cell death-ligand 1 (sPD-L1) remains unclear. We here investigated the relation between the efficacy of PD-1 blockade and pretreatment plasma levels of sPD-1 and sPD-L1 across a broad range of cancer types.

Methods

We retrospectively analyzed clinical data from 171 patients with advanced solid tumors who received nivolumab or pembrolizumab monotherapy regardless of treatment line. The concentrations of sPD-1 and sPD-L1 were measured with a fully automated immunoassay (HISCL system).

Results

The study subjects comprised patients with head and neck cancer (n = 50), urothelial cancer (n = 42), renal cell cancer (n = 37), gastric cancer (n = 20), esophageal cancer (n = 10), malignant pleural mesothelioma (n = 6), or microsatellite instability-high tumors (n = 6). High or low levels of sPD-1 or sPD-L1 were not significantly associated with progression-free survival (PFS) or overall survival (OS) for PD-1 blockade in the entire study population. Comparison of treatment outcomes according to combinations of high or low sPD-1 and sPD-L1 levels, however, revealed that patients with low sPD-1 and high sPD-L1 concentrations had a significantly poorer PFS (HR of 1.79 [95% CI, 1.13-2.83], p = 0.01) and a tendency toward poorer OS (HR of 1.70 [95% CI, 0.99-2.91], p = 0.05) compared with all other patients.

Conclusion

Our findings suggest that the combination of low sPD-1 and high sPD-L1 levels is a potential negative biomarker for PD-1 blockade therapy.

Combined laryngeal framework surgery and cricopharyngeal muscle-origin transection: a novel effective surgery for dysphagia with pharyngolaryngeal palsy and cricopharyngeal dysfunction under local anesthesia

BACKGROUND

Cricopharyngeal myotomy and laryngeal framework surgery can improve swallowing function in patients with severe dysphagia. We developed a novel surgical technique for severe dysphagia associated with pharyngolaryngeal paralysis and cricopharyngeal dysfunction, performed under local anesthesia, and investigated its effectiveness.

METHODS

We included nine patients who underwent cricopharyngeal muscle-origin transection with laryngeal framework surgery through a horizontal skin incision under local anesthesia.

CONCLUSIONS

All patients demonstrated significant improvement in the Food Intake LEVEL Scale without complications. Thus, this surgical technique may serve as a useful and less invasive treatment option for patients with severe dysphagia.

Transplantation of autologous bone marrow-derived mononuclear cells into cerebrospinal fluid in a canine model of spinal cord injury

Introduction

Spinal cord injury (SCI) is associated with severe dysfunction of nervous tissue, and repair via the transplantation of bone marrow-derived mononuclear cells (BM-MNCs) into cerebrospinal fluid yields promising results. It is essential to understand the underlying mechanisms; therefore, this study aimed to evaluate the regenerative potential of autologous BM-MNC transplantation in a canine model of acute SCI.

Methods

Six dogs were included in this study, and SCI was induced using an epidural balloon catheter between L2 and L3, particularly in the area of the anterior longitudinal ligament. BM-MNC transplantation was performed, and T2-weighted magnetic resonance imaging (MRI) was conducted at specific time points (i.e., immediately after inducing SCI and at 1, 2, and 4 weeks after inducing SCI); moreover, the expression of growth-associated protein 43 (GAP-43) was evaluated.

Results

MRI revealed that the signal intensity reduced over time in both BM-MNC-treated and control groups. However, the BM-MNC-treated group exhibited a significantly faster reduction than the control group during the early stages of SCI induction (BM-MNC-treated group: 4.82 ± 0.135 cm [day 0], 1.71 ± 0.134 cm [1 week], 1.37 ± 0.036 cm [2 weeks], 1.21 cm [4 weeks]; control group: 4.96 ± 0.211 cm [day 0], 2.49 ± 0.570 cm [1 week], 1.56 ± 0.045 cm [2 weeks], 1.32 cm [4 weeks]). During the early stages of treatment, GAP-43 was significantly expressed at the proximal end of the injured spinal cord in the BM-MSC-treated group, whereas it was scarcely expressed in the control group.

Conclusions

In SCI, transplanted BM-MNCs can activate the expression of GAP-43, which is involved in axonal elongation (an important process in spinal cord regeneration). Thus, cell therapy with BM-MNCs can provide favorable outcomes in terms of better regenerative capabilities compared with other therapies.

Transplantation of Induced Pluripotent Stem Cell-Derived Airway Epithelia with a Collagen Scaffold into the Nasal Cavity

The nasal cavity is covered with respiratory epithelia, including ciliated cells that eliminate foreign substances trapped in the mucus. In hereditary diseases such as primary ciliary dyskinesia and cystic fibrosis, respiratory epithelial functions are irreversibly impaired; however, no radical treatment has been established yet. Thus, we considered that the transplantation of normal airway epithelia (AE) into the nasal epithelia is one of the strategies that could lead to radical treatment in the future. In our previous study, human induced pluripotent stem cell-derived AE (hiPSC-AE) on the vitrigel membrane were transplanted into the scraped area of the nasal septal mucosa of nude rats. Although human-derived ciliated cells, club cells, and basal cells were observed, they were located in the cysts within the submucosal granulation tissue but not in the nasal mucosal epithelia and the transplanted cells may not contribute to the function of the nasal mucosa with this condition. Therefore, to achieve more functional transplantation, we prepared the graft differently in this study by wrapping the collagen sponge in hiPSC-AE on the vitrigel membrane. As a result, we found the transplanted cells surviving in the nasal mucosal epithelia. These results suggest that hiPSC-AE transplanted into the nasal cavity could be viable in the nasal mucosa. In addition, our method leads to the establishment of nasal mucosa-humanized rats that are used for the development of the drugs and therapeutic methods for hereditary diseases of nasal respiratory epithelia.

Parathyroid carcinoma: impact of preoperative diagnosis on the choice of surgical procedure

The operative procedure in the surgical treatment of parathyroid carcinoma differs from that of benign hyperparathyroidism. However, preoperative differentiation is often difficult. This study elucidated how clinicians diagnose parathyroid carcinoma and the relationship between preoperative diagnosis and the operative course. Using a retrospective chart review, twenty cases of parathyroid carcinoma from nine participating centers were examined. In 11 cases with preoperative suspicion of malignancy, at least one of these three features was found: elevated serum calcium level (>14 mg/dL), palpable mass, and irregular margin on ultrasonography. Although an intact parathyroid hormone (iPTH) threshold to suspect malignancy has not been established, six cases showed marked iPTH elevation exceeding 8.0 times the upper limit of normal. One case was excluded from analysis due to hemodialysis. Compared with the four cases that showed calcium elevation, the iPTH threshold might represent better sensitivity. Among 9 cases of benign preoperative diagnosis, six cases were performed with pericapsular resection. In three cases where malignancy was suspected in the middle of the operation, the recommended en bloc resection with ipsilateral thyroid lobectomy was not performed but a parathyroidectomy with surrounding soft tissue. In contrast, 10 preoperatively suspected cases underwent en bloc resection, and one case underwent pericapsular resection followed by supplementary ipsilateral hemithyroidectomy due to the uncertain pre- and intraoperative findings to determine the diagnosis. In conclusion, the surgical procedure for parathyroid carcinoma strongly depends on the preoperative diagnosis. The presence of excessive iPTH levels might contribute to improved preoperative diagnostic sensitivity for parathyroid carcinoma.

Local coordination of epithelial planar polarity in the maintenance and regeneration of the adult rat airway

The maintenance of planar polarity in airway multiciliated cells (MCCs) has been poorly characterized. We recently reported that the direction of ciliary beating in a surgically inverted tracheal segment remained inverted beyond the time required for the turnover of cells, without adjustment to global distal-to-proximal polarity. We hypothesized that the local maintenance of tissue-level polarity occurs via locally reproduced cells. To provide further insight regarding this hypothetical property, we performed allotransplantation of an inverted tracheal segment between wild-type (donor) and tdTomato-expressing (host) rats, with and without scratching the mucosa of the transplants. The origin of cells in the transplants was assessed using tdTomato-specific immunostaining. Ciliary movement and structures were observed by high-speed video and electron microscopy to analyze MCC orientations. Variabilities in the orientations of closely and distantly located MCCs were analyzed to evaluate the local- and broad-scale coordination of polarity, respectively. The epithelium was maintained by donor-derived cells in the non-scratched inverted transplant over 6 months, beyond one cycle of turnover. The inverted orientation of MCCs was also maintained throughout the non-scratched transplant. MCCs regenerated in the scratched transplant were derived from the host and exhibited diverse orientations across the transplant. However, the orientations of adjacent regenerated MCCs were often coordinated, indicating that airway MCCs can locally coordinate their orientations. A steady-state airway may maintain MCC orientation by locally reproducing MCCs via the local coordination of polarity. This local coordination enables the formation and maintenance of tissue-level polarity in small regions after mucosal injury.

Characteristics of oral squamous cell carcinoma focusing on cases unaffected by smoking and drinking: A multicenter retrospective study

BACKGROUND

Some oral squamous cell carcinoma (OSCC) cases are unaffected by smoking or drinking. This study aimed to clarify distinctive groups among OSCC patients and examine the characteristics of multiple primary carcinomas (MPCs).

METHODS

We analyzed data from 970 patients. The patients were divided into three groups: all individuals <45 years (<45 y), smokers/drinkers ≥45 years (SD ≥45 y), and non-smokers/non-drinkers ≥45 years (NSND ≥45 y).

RESULTS

Tongue cancers were more common in the <45 y group than in the other groups (p < 0.001). The NSND ≥45 y group was significantly older and more likely to be female than the SD ≥45 y group (p < 0.001). MPCs in the upper aerodigestive tract were more common in men and smokers/drinkers, whereas women were at risk for multiple primary OSCCs (p = 0.022).

CONCLUSIONS

The "young tongue" and "elderly female" subgroups and characteristics of MPCs suggest carcinogenic factors of OSCC other than smoking and drinking.

Development of Novel Layered Polyglycolic Acid Sheet for Regeneration of Critical-Size Defect in Rat Trachea

OBJECTIVES

Polyglycolic acid sheets are difficult to adapt to the central airway because of poor durability against high air pressure. Therefore, we developed a novel layered polyglycolic acid material to cover the central airway and examined its morphologic traits and functional performance as a potential tracheal replacement.

METHODS

A critical-size defect in rat cervical tracheas was covered with the material. Morphologic changes were bronchoscopically and pathologically evaluated. Functional performance was evaluated by regenerated ciliary area, ciliary beat frequency, and ciliary transport function determined by measuring the moving distance of microspheres dropped onto the trachea (µm/s). The evaluation time points were 2 weeks, 1 month, 2 months, and 6 months after surgery (n = 5, respectively).

RESULTS

Forty rats underwent implantation, and all survived. Histological examination confirmed ciliated epithelization on the luminal surface after 2 weeks. Neovascularization was observed after 1 month, tracheal glands after 2 months, and chondrocyte regeneration after 6 months. Although the material was gradually replaced by self-organization, tracheomalacia was not bronchoscopically observed at any time point. The area of regenerated cilia significantly increased between 2 weeks and 1 month (12.0% vs 30.0%; p = 0.0216). The median ciliary beat frequency significantly improved between 2 weeks and 6 months (7.12 vs 10.04 Hz; p = 0.0122). The median ciliary transport function was significantly improved between 2 weeks and 2 months (5.16 vs 13.49 µm/s; p = 0.0216).

CONCLUSIONS

The novel polyglycolic acid material showed excellent biocompatibility and tracheal regeneration both morphologically and functionally 6 months after tracheal implantation.

A multicenter study to investigate the positive rate of SARS-CoV-2 in middle ear and mastoid specimens from otologic surgery patients

OBJECTIVE

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus, causes coronavirus disease 2019 (COVID-19). Otologic surgeries with drilling by powered instruments induce significant aerosols, which may induce SARS-CoV-2 transmission to medical staff if SARS-CoV-2 exists in the middle ear and mastoid cavity. During a COVID-19 pandemic, therefore, confirming a negative COVID-19 test prior to otologic surgery is recommended. However, previous coronavirus studies demonstrated that coronavirus was detected in the middle ear in some patients even though the polymerase chain reaction (PCR) test using their nasopharyngeal swab was negative. This study aimed to elucidate the probability of a positive SARS-CoV-2 PCR test in the middle ear or mastoid specimens from otologic surgery patients in whom SARS-CoV-2 was not detected by preoperative PCR test using a nasopharyngeal swab.

METHODS

We conducted a prospective, multicenter clinical study. Between April 2020 and December 2021, during the COVID-19 pandemic, 251 ears of the 228 participants who underwent otologic surgery were included in this study. All participants had no symptoms suggesting COVID-19 or close contact with a confirmed COVID-19 patient two weeks prior to the surgery. They were also negative in the SARS-CoV-2 PCR tests using a nasopharyngeal swab before surgery. We collected mucosa, granulation, bone dust with mucosa or fluid from the middle ear or mastoid for the SARS-CoV-2 PCR tests during each otologic surgery.

RESULTS

The median age of the participants at surgery was 31.5 years old. Mastoidectomy using a powered instrument was conducted in 180 of 251 otologic surgeries (71.8%). According to intraoperative findings, active inflammation in the middle ear or mastoid cavities was evident in 20 otologic surgeries (8.0%), while minor inflammation was observed in 77 (30.7%). All SARS-CoV-2 PCR tests of otologic specimens showed a negative result. No patient suffered from COVID-19 within two months after otologic surgery. Furthermore, no hospital-acquired infections associated with otologic surgery occurred in our institutions CONCLUSIONS: Our results showed that PCR testing did not detect SARS-CoV-2 in middle ear and mastoid specimens, suggesting that the risk of transmission of SARS-CoV-2 is not high in otologic surgeries even using powered instruments when both clinical and laboratory tests are confirmed to be negative for COVID-19.

A prospective evaluation of postoperative swallowing function and dysphagia following endoscopic laryngopharyngeal surgery

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.

Intraoperative computed tomography imaging for laryngoplasty

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.

Detection of Tip Fold-Over of the Slim Modiolar Electrode Using Intraoperative Mobile Cone-Beam Computed Tomography

OBJECTIVE

This study aimed to evaluate the importance of mobile cone-beam computed tomography in detecting tip fold-over of a slim modiolar electrode within the cochlea during surgery.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary medical center.

METHODS

From January 2020 to June 2022, 33 ears of 30 patients with normal cochlear morphology underwent cochlear implantation with slim modiolar electrodes and intraoperative mobile cone-beam computed tomography imaging. Furthermore, we retrospectively reviewed the medical records and images.

RESULTS

The tip fold-over of the electrodes was detected using mobile cone-beam computed tomography in 3 out of 33 ears (9.1%). We could not identify the tip fold-over by scouting plain X-ray images in 2 out of 3 cases before taking the cone-beam computed tomography images. Electrode removal and reinsertion were performed before wound closure and the successful reinsertion was confirmed by mobile cone-beam computed tomography. The folded electrode tips were located at 238.8°, 152°, and 185.8°.

CONCLUSION

Intraoperative mobile cone-beam computed tomography is useful in detecting the tip fold-over of the slim modiolar electrodes during surgery. Therefore, it was possible to reinsert the electrodes in all cases before closing the wound, eliminating the need for revision surgeries. Moreover, the analysis of mobile cone-beam computed tomography images may help to elucidate the mechanisms of electrode tip fold-over.

Laryngeal Cartilage Regeneration of Nude Rats by Transplantation of Mesenchymal Stem Cells Derived from Human-Induced Pluripotent Stem Cells

Previous studies transplanted human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) into thyroid cartilage defect of X-liked severe combined immunodeficiency (X-SCID) rats and confirmed transplanted cell survival and cartilage regeneration. Thus, this study aimed to investigate the contribution of iMSC transplantation to thyroid cartilage regeneration of nude rats. iMSCs were induced from hiPSCs via a neural crest cell lineage. Then, clumps formed from an iMSC/extracellular matrix complex were transplanted into thyroid cartilage defects in nude rats. The larynx was removed and histological and immunohistochemical analyses were performed 4 or 8 weeks after the transplantation. Human nuclear antigen (HNA)-positive cells were observed in 11 of 12 (91.7%) rats, which indicated that transplanted iMSCs survived in thyroid cartilage defects in nude rats. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells in 8 of 12 rats (66.7%), which indicated cartilage-like regeneration. Cartilage-like regeneration in nude rats in this study was comparable to the previous report on X-SCID rats (HNA-positive cells were observed in all 14 rats and cartilage-like regeneration was observed in 10 of 14 rats). This result suggests that nude rats could be an alternative to X-SCID rats in thyroid cartilage regeneration experiments using iMSCs, and this nude rat cartilage transplantation model may develop cartilage regeneration research concerning fewer problems such as infection due to immunosuppression.

Long-term survival outcomes and recurrence patterns of olfactory neuroblastoma: A 13-year experience at a single institution

OBJECTIVES

Olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma, is a rare malignant neoplasm of the nasal vault and anterior skull base. The results of treatment for ONB are relatively good; however, regional and distant metastases can develop several years after definitive treatment. This study aimed to validate the treatment modality of ONB for oncological outcomes, especially for regional recurrence.

METHODS

We retrospectively reviewed the medical records of 22 patients diagnosed with ONB at Kyoto University Hospital between 2009 and 2020. Descriptive statistics were calculated, and Kaplan-Meier curves were used.

RESULTS

The median follow-up time was 58.2 months. One (4.5%) patient was clinically node positive, (cN+) and the remaining 21 (95.5%) were clinically node negative (cN0) at presentation. Eighteen patients underwent an endoscopic endonasal approach (EEA) for primary resection, and the remaining four patients underwent a combined EEA and transcranial approach. Elective neck dissection was not performed for 21 patients with cN0 ONB, whereas unilateral neck dissection with removal of ipsilateral lateral retropharyngeal node was performed for one patient with cN+ ONB. Postoperative radiotherapy without concurrent chemotherapy was performed only at the primary tumor bed for 21 patients with cN0 ONB, and at the primary tumor bed and bilateral neck for one patient with cN+ ONB. The 5-year overall, disease-specific, and disease-free survival rates were 94.1%, 100%, and 69.6%, respectively. No patients developed local recurrence, but 6 (27.2%) patients experienced recurrence with a median time to recurrence of 36.4 months, including four and two patients who initially developed regional recurrences and bone metastases, respectively. Five (22.7%) patients had delayed neck recurrence. The salvage rate was only 60.0% in the five patients who had delayed neck recurrence. Regarding the level of delayed neck recurrence, 4 (18.2%) patients had lateral retropharyngeal lymph node metastases.

CONCLUSION

Patients with ONB have excellent survival outcomes after endoscopic surgical resection of the primary lesion with postoperative radiotherapy only to the primary tumor bed. Despite excellent survival, delayed neck recurrence, including the lateral retropharyngeal lymph node, remains high. Because salvage surgery for lateral retropharyngeal lymph node recurrence is sometimes technically difficult, it may be better to extend the field of postoperative radiotherapy from the primary tumor bed only to include bilateral lateral retropharyngeal lymph node regions in patients with clinically N0 ONB. Further prospective studies with a large number of patients are needed to determine the extent of postoperative radiotherapy.

Outcomes of Aspiration Prevention Surgery: A Retrospective Cohort Study Using a Japanese Claims Database

Aspiration prevention surgeries, such as laryngotracheal separation and total laryngectomy are performed to prevent aspiration pneumonia. We aimed to investigate the outcomes of surgery for intractable aspiration and relevant factors. This retrospective cohort study used a nationwide insurance claims database that included company employees and their family members aged < 75 years in Japan. We extracted the data of patients who underwent aspiration prevention surgeries between January 2005 and March 2019. We identified 127 patients (males, 55.9%), of whom 59.8% were aged < 18 years at the surgery. The most common comorbidity was neurological disease (99.2%). The frequency of pneumonia episodes decreased by 1.5 per year after surgery compared with before surgery (p < 0.001). Among patients who received parenteral and enteral nutrition before surgery (n = 92), the adjusted hazard ratio (aHR) for oral intake without parenteral and enteral nutrition was lower in the longer preoperative duration (≥ 14.7 months) for the parenteral and enteral nutrition. However, the difference was not statistically significant (aHR 0.55; 95% confidence interval: 0.15-2.08, p = 0.38). The aHR for oral intake was higher in the ≥ 30 years group than in the < 30 years group (aHR 13.76; 95% confidence intervals: 4.18-42.24; p < 0.001). This study demonstrated that postoperative oral intake was achieved more frequently in patients aged ≤ 30 years than in those aged > 30 years, and supported the effectiveness of aspiration prevention surgery for reducing aspiration pneumonia. Further research is necessary to investigate factors related to postoperative oral intake.

The added value of non-contrast 3-Tesla MRI for the pre-operative localization of hyperparathyroidism

OBJECTIVE

We investigated the efficacy of non-contrast 3-Tesla MR imaging added to the combination of sestamibi with^99mTc (MIBI) scintigraphy and Ultrasonography (US) for the pre-operative localization of Primary Hyperparathyroidism (PHPT) lesions.

METHODS

A total of 34 parathyroid glands, including nine normal glands, were examined with MIBI, US, and non-contrast 3-Tesla MRI. MRI was performed with the acquisition of T1- and T2-weighted images and fat-suppressed T2-weighted images. We calculated the sensitivities of MIBI, US, and the 'additional' MRI, with knowledge of the former two modalities' results.

RESULTS

For the diagnosis of PHPT lesions, the sensitivity values of MIBI, US, and additional MRI were 88.0% (22/25), 84.0% (21/25), and 92.0% (23/25), respectively. Normal glands were not visualized with any modality (0/9). One lesion was detected neither with US nor MRI, but only with MIBI, with the limitation that MIBI represented no more than laterality. The two glands not identified in MRI were 4 mm and 6 mm in their size, which are within the range of normal gland's size. Two lesions were not detected with US or MIBI but were visualized with the additional MRI, which indicated that the MRI contributed an 8.0% (2/25) improvement of sensitivity, compared from that of US. Fat-suppressed T2-weighted images were useful in the identification of parathyroid lesions, as these images helped to differentiate between the lesion and the adjacent tissue.

CONCLUSION

Additional non-contrast 3-Tesla MRI was a useful adjunctive tool for localization of PHPT, which improved the sensitivity of the pre-operative localization of PHPT lesions. Fat-suppressed T2-weighted images contributed to their identification.

LEVEL VI

Evidence from a single descriptive or qualitative study.

A 14-year nationwide epidemiological analysis of delayed endolymphatic hydrops in Japan

BACKGROUND

Delayed endolymphatic hydrops (DEH) is an inner ear disease that causes recurrent vertigo in the ipsilateral ear or fluctuating hearing in the contralateral ear due to endolymphatic hydrops secondary to preceding deafness. There are few reports of large, multicentre studies investigating the clinical-epidemiological characteristics of DEH.

OBJECTIVE

This study aimed to clarify the characteristics of DEH in Japan.

METHODS

Clinical data on 662 patients with DEH were analysed by nationwide, multicentre surveys conducted by the Peripheral Vestibular Disorders Research Group of Japan.

RESULTS

The proportion of ipsilateral DEH (IDEH) was slightly higher than that of contralateral DEH (CDEH) at 55.4%. The time delay between onset of precedent deafness and onset of DEH was significantly longer for CDEH than for IDEH. The most common cause of precedent deafness was a disease of unknown cause with onset in early childhood (33.1%). Epidemiological characteristics were not significantly different between CDEH with and without vertigo.

CONCLUSION

DEH appearing to be caused by viral labyrinthitis has a high rate of onset within 40 years of precedent deafness. Clinical and epidemiological characteristics of IDEH, CDEH with vertigo, and CDEH without vertigo were very similar.

SIGNIFICANCE

The clinical-epidemiological characteristics of DEH in Japan were clarified.

Peroxisome Proliferator-Activated Receptor-γ Agonist Attenuates Vocal Fold Fibrosis in Rats via Regulation of Macrophage Activation

Macrophages aid in wound healing by changing their phenotype and can be a key driver of fibrosis. However, the contribution of macrophage phenotype to fibrosis following vocal fold injury remains unclear. Peroxisome proliferator-activated receptor-γ (PPARγ) is expressed mainly by macrophages during early wound healing and regulates the macrophage phenotype. This study aimed to evaluate the effects of pioglitazone (PIO), a PPARγ agonist, on the macrophage phenotype and fibrosis following vocal fold injury in rats. PIO was injected into the rat vocal folds on days 1, 3, 5, and 7 after injury, and the vocal fold lamina propria was evaluated on days 4 and 56 after injury. Moreover, THP-1-derived macrophages were treated with PIO, and the expression of proinflammatory cytokines under lipopolysaccharide/interferon-γ stimulation was analyzed. PIO reduced the expression of Ccl2 both in vivo and in vitro. Furthermore, PIO decreased the density of inducible nitric oxide synthase⁺ CD68⁺ macrophages and inhibited the expression of fibrosis-related factors on day 4 after injury. On day 56 after injury, PIO inhibited fibrosis, tissue contracture, and hyaluronic acid loss in a PPARγ-dependent manner. These results indicate that PPARγ activation could inhibit accumulation of inflammatory macrophages and improve tissue repair. Taken together, these findings imply that inflammatory macrophages play a key role in vocal fold fibrosis.

Efficient Bone Conduction Hearing Device with a Novel Piezoelectric Transducer Using Skin as an Electrode

OBJECTIVE

Bone conduction hearing aids are the only non-surgical devices used for conductive hearing loss. However, they are impractical for lifelong use since they require close contact of the transducer with the head skin, causing skin erosion and discomfort. Bone conduction hearing implants and active middle ear implants do not present these issues; however, they require surgery and can sometimes cause issues in the skin surrounding the devices. This study aimed to develop a new bone conduction hearing device that does not exert pressure on the skin or require surgery.

METHODS

Our device modified a piezoelectric element by using the skin of a pinna as one of the two electrodes of a conventional piezoelectric device. We compared the sound transmission of a speaker, a conventional piezoelectric device, or the new device to the guinea pig cochlea, a physiological sound transducer to the auditory nerve, in normal and air-conductive hearing loss conditions.

RESULTS

The novel device transmitted sound to the cochlea even after causing air-conductive hearing loss. Its bone conduction was more efficient than the speaker and the conventional piezoelectric device.

CONCLUSION

We developed a novel type of bone conduction device that efficiently transmits sound to the cochlea by skipping the external auditory canal, tympanic membrane, and middle ear ossicles. This device does not exert pressure on the skin that can result in skin damage, an adverse effect of a conventional bone conduction hearing aid.

SIGNIFICANCE

Our novel hearing device can be used as a substitute for current bone-conduction hearing devices.

Inhibition of EGFR and MEK surmounts entrectinib resistance in a brain metastasis model of NTRK1-rearranged tumor cells

Tropomyosin receptor kinase (TRK) inhibitors have demonstrated histology-agnostic efficacy in patients with neurotrophic receptor tyrosine kinase (NTRK) gene fusion. Although responses to TRK inhibitors can be dramatic and durable, duration of response may eventually be limited by acquired resistance via several mechanisms, including resistance mutations such as NTRK1-G595R. Repotrectinib is a second-generation TRK inhibitor, which is active against NTRK1-G595R. However, its efficacy against entrectinib-resistant tumors has not been fully elucidated. In the present study, we established entrectinib-resistant tumor cells (M3B) in a brain metastasis model inoculated with NTRK1-rearranged KM12SM cells, and examined the sensitivity of M3B cells to repotrectinib. While M3B cells harbored the NTRK1-G595R mutation, they were unexpectedly resistant to repotrectinib. The resistance was due to extracellular signal-regulated kinase (ERK) reactivation partially mediated by epidermal growth factor receptor (EGFR) activation. We further demonstrate that the triplet combination of repotrectinib, EGFR inhibitor, and MEK inhibitor could sensitize M3B cells in vitro as well as in a brain metastasis model. These results indicate that resistant mutations, such as NTRK1-G595R, and alternative pathway activation, such as ERK activation, could simultaneously occur in entrectinib-resistant tumors, thereby causing resistance to second-generation inhibitor repotrectinib. These findings highlight the importance of intensive examinations to identify resistance mechanisms and application of the appropriate combination treatment to circumvent the resistance.

Prognosis of otitis media with effusion in pediatric patients with cleft palate during language-acquisition period treated by simultaneous tympanostomy tube placement with palatoplasty

OBJECTIVE

Cleft palate (CP) in children is frequently complicated by otitis media with effusion (OME) due to Eustachian tube dysfunction. Although tympanostomy tube (TT) placement can be beneficial in the treatment of OME to prevent short-term hearing loss, there is no consensus regarding the indications for and timing of TT insertion. The present study was performed to define the safety and effectiveness of simultaneous TT placement with palatoplasty during the language-acquisition period.

METHODS

We retrospectively reviewed the medical charts of pediatric patients who underwent palatoplasty for CP in a tertiary medical center, Kyoto University Hospital, from June 2010 to October 2018. The TT retention time was estimated using the Kaplan-Meier method. The incidence of OME recurrence was compared among four Veau classification groups based on the patients' sex, type of CP, median TT retention time, and type of fluid.

RESULTS

Seventy-six subjects (150 ears) were enrolled in the study. The median follow-up duration was 48.7 months (range, 18.2-108.0 months) after the first TT placement. A first TT retention time of <20.1 months was a significant risk factor for OME recurrence. Subjects with maxillofacial anomaly complex and subjects with cleft lip and palate and an alveolar cleft showed a significantly higher OME recurrence rate than subjects with clefts only in the hard and/or soft palate. There was no significant difference in the occurrence of sequelae between subjects with only a single TT placement and subjects with more than one TT placement.

CONCLUSIONS

Based on the findings of the present study, it is reasonable to perform TT insertion at the same time as palatoplasty on patients who meet the indications. This technique may reduce the number of times the patient requires general anesthesia and maintain good middle ear condition during the period of language acquisition between 1 and 3 years of age.

Preoperative Localization of Parathyroid Adenomas with Diffusion MR Imaging: Readout-segmented versus Single-shot Echo-planar Imaging

PURPOSE

To evaluate whether readout-segmented echo-planar imaging (RS-EPI) diffusion-weighted imaging (DWI) can reduce image distortion and improve the lesion identification in parathyroid adenomas (PTAs) compared to single-shot EPI (SS-EPI) DWI, and to determine whether PTAs can be differentiated from other soft tissue structures of the head and neck region by using the apparent diffusion coefficient (ADC) value.

METHODS

We retrospectively analyzed the preoperative MR images including DWI of 24 patients with surgically confirmed PTA. RS-EPI and SS-EPI DWI were evaluated by two independent readers for the identification of the lesions and distortion. The ADC values of the PTAs were compared with those of thyroid glands and cervical lymph nodes.

RESULTS

RS-EPI provided significantly less distortion compared to SS-EPI. RS-EPI tended to have better lesion identification compared with SS-EPI without a statistically significant difference. On SS-EPI, the PTAs had significantly higher ADC values compared with the cervical lymph nodes. On RS-EPI, the PTAs had significantly higher ADC values compared with the thyroid glands and cervical lymph nodes.

CONCLUSION

RS-EPI reduces the DWI distortion in PTAs. The ADC value obtained using RS-EPI enables the differentiation of PTAs from nearby structures, such as thyroid glands and cervical lymph nodes.

Transplantation of a human induced pluripotent stem cell-derived airway epithelial cell sheet into the middle ear of rats

Introduction

Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats.

Methods

Following the preparation of AEC sheets from hiPSCs, the bilateral middle ear mucosa of X-linked severe combined immunodeficient rats was scraped, and the AEC sheets were transplanted in the ears unilaterally.

Results

Human nuclear antigen (HNA)-positive ciliated cells were observed on the transplanted side of the middle ear cavity surface in three of six rats in the 1-week postoperative group and in three of eight rats in the 2-week postoperative group. No HNA-positive cells were found on the control side. The percentage of HNA-positive ciliated cells in the transplanted areas increased in the 2-week postoperative group compared with the 1-week group, suggesting survival of hiPSC-derived AECs. Additionally, HNA-positive ciliated cells were mainly located at sites where the original ciliated cells were localized. Immunohistochemical analysis showed that the transplanted AECs contained cytokeratin 5- and mucin 5AC-positive cells, indicating that both basal cells and goblet cells had regenerated within the middle ear cavity.

Conclusions

The results of this study are an important first step in the establishment of a novel transplantation therapy for chronic otitis media.

•

hiPSC-derived airway epithelial cells were transplanted into the middle ear of rats.

•

Engrafted cells mainly survived in the ciliated region of the middle ear.

•

Ciliated, goblet, and basal cells were confirmed in the engrafted cells.

Weekly Cisplatin Plus Radiation for Postoperative Head and Neck Cancer (JCOG1008): A Multicenter, Noninferiority, Phase II/III Randomized Controlled Trial

PURPOSE

The standard treatment for postoperative high-risk locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) is chemoradiotherapy with 3-weekly cisplatin (100 mg/m²). However, whether chemoradiotherapy with weekly cisplatin (40 mg/m²) yields comparable efficacy with 3-weekly cisplatin in postoperative high-risk LA-SCCHN is unknown.

PATIENTS AND METHODS

In this multi-institutional open-label phase II/III trial, patients with postoperative high-risk LA-SCCHN were randomly assigned to receive either chemoradiotherapy with 3-weekly cisplatin (100 mg/m²) or with weekly cisplatin (40 mg/m²) to confirm the noninferiority of weekly cisplatin. The primary end point of phase II was the proportion of treatment completion, and that of phase III was overall survival. A noninferiority margin of hazard ratio was set at 1.32.

RESULTS

Between October 2012 and December 2018, a total of 261 patients were enrolled (3-weekly cisplatin, 132 patients; weekly cisplatin, 129 patients). At the planned third interim analysis in the phase III part, after a median follow-up of 2.2 (interquartile range 1.19-3.56) years, chemoradiotherapy with weekly cisplatin was noninferior to 3-weekly cisplatin in terms of overall survival, with a hazard ratio of 0.69 (99.1% CI, 0.374 to 1.273 [< 1.32], one-sided P for noninferiority = .0027 < .0043). Grade 3 or more neutropenia and infection were less frequent in the weekly arm (3-weekly v weekly, 49% v 35% and 12% v 7%, respectively), as were renal impairment and hearing impairment. No treatment-related death was reported in the 3-weekly arm, and two (1.6%) in the weekly arm.

CONCLUSION

Chemoradiotherapy with weekly cisplatin is noninferior to 3-weekly cisplatin for patients with postoperative high-risk LA-SCCHN. These findings suggest that chemoradiotherapy with weekly cisplatin can be a possible treatment option for these patients.

Microscopic observation of human airway ciliary movement using wheat germ agglutinin

Ciliated cells in the airway epithelium generate mucus streams to remove extraneous particles and microorganisms by beating the motile cilia. This defense mechanism is crucial for maintaining homeostasis and preventing infection in the airway. Conventional methods to assess ciliary beating have revealed that rapid (>10 times per second) and metachronal beating of cilia enables efficient mucus transport. Cilia are oriented to excrete mucus toward the outside of the body. However, conventional methods to directly observe ciliary movements uses transmitted light, which requires translucent samples. Sliced or fragmented tissues are used to observe ciliary movements in thick human airway tissues. Therefore, conventional methods are unsuitable for assessing in situ orientation of ciliary movements. The orientation of ciliary beating can be indirectly analyzed by tracking particles spread onto the epithelium; however, the particles are not efficiently transported by immature cilia. To address this issue, we developed a method for labeling airway motile cilia with fluorescently labeled wheat germ agglutinin (FL-WGA). The new method enables microscopic observation of ciliary movements without slicing or fragmenting the airway tissues. Since the airway epithelium is observed from the apical side, in situ orientation of ciliary beating can be analyzed using this method. Additionally, epithelial damage, and the number and maturity of cilia can be assessed during the observation of ciliary beating. The new method, in combination with other methods, can provide more comprehensive data regarding ciliary movements.

The RNA Methylation Modification 5-Methylcytosine Impacts Immunity Characteristics, Prognosis and Progression of Oral Squamous Cell Carcinoma by Bioinformatics Analysis

Disorders pertaining to 5-methylcytosine (m5C) modifications are involved in the pathological process of many diseases. However, the effect of m5C on the tumorigenesis and progression of oral squamous cell carcinoma (OSCC) remains unclear. In this study, we integrated the genomic and clinical data of 558 OSCC samples to comprehensively evaluate m5C modification patterns. Based on 16 m5C methylation regulators, two m5C modification clusters were identified with distinct tumor immune microenvironment (TIME) characteristics and prognosis in OSCC. We then performed weighted gene co-expression network analysis (WGCNA) to identify m5C modification cluster-related modules. Genes in the selected module were chosen to construct the m5Cscore scoring system for evaluating m5C modification pattern in individual OSCC patients. Patients with a high m5Cscore had higher immune, stromal, and ESTIMATE scores; lower tumor purity score; lower immune activity; and higher tumor mutational burden. The overall survival rate and progression-free survival rate were markedly worse and the tumor recurrence rate was higher in OSCC patients with a high m5Cscore. Furthermore, patients with oral leukoplakia who also had a high m5Cscore had a higher risk of deterioration to OSCC. This study demonstrated that m5C modification patterns might affect the TIME in OSCC. m5Cscore may provide a new approach for predicting the prognosis and progression of OSCC.