Current management of carotid body tumors

Carotid body tumors (CBTs) are neoplasms that occur at the bifurcation of the carotid artery and are pathologically classified as paragangliomas. In the 4th edition of the WHO classification, paragangliomas are categorized as neoplasms with malignant potential. Clinically, about 5% of CBTs present with malignant features such as metastasis. Currently, it is challenging to distinguish between tumors with benign courses and those that present malignantly. Recent advances in genetic testing have elucidated the genetic characteristics of paragangliomas, including carotid body tumors. Over 20 genes have been identified as being involved in tumor development. Particularly in head and neck paragangliomas, abnormalities in genes related to succinate dehydrogenase are frequently observed. Research is ongoing to understand the mechanisms by which these genes contribute to tumor development. The definitive treatment for CBTs is surgical resection. These tumors are prone to bleeding and often adhere firmly to the carotid artery, making intraoperative bleeding control challenging. The risk of lower cranial nerve paralysis is relatively high, and there is a risk of stroke because of manipulation of the carotid artery. Preoperative evaluation with angiography is essential, and a multi-disciplinary surgical team approach is necessary. In cases where the tumor is difficult to resect or has metastasized, radiation therapy or chemotherapy are employed. Clinical trials involving targeted molecular therapies and radiopharmaceuticals have recently been conducted, with some applied clinically. The development of various new treatments is anticipated, providing hope for therapeutic options in refractory cases.

Low-Dose Cisplatin-Based Radiation Therapy for Refractory Recurrent Respiratory Papillomatosis

Recurrent respiratory papilloma (RRP) often presents multiple lesions in the respiratory tract and sometimes becomes fatal because of severe airway obstruction. We report the case of a 69-year-old woman who had juvenile-onset RRP in the trachea that was refractory to surgical treatment, and complete remission was achieved by low-dose cisplatin combined with de-escalated radiotherapy without any side effects. This case report is the first to illustrate the data on low-dose cisplatin for refractory benign RRP, and our experience reinforces the opinion that low-dose cisplatin combined with de-escalated radiotherapy can be an effective and safe treatment alternative for uncontrollable and lethal RRP. Laryngoscope, 134:2335-2337, 2024.

Characteristic Laryngeal Findings in Patients with Pemphigus Vulgaris

OBJECTIVE

Pemphigus Vulgaris (PV) is a rare autoimmune disease that could cause laryngeal lesions; however, only a few studies have described the localization of the laryngeal lesions associated with this disease owing to its rarity. Therefore, this study aimed to determine the localization of laryngeal lesions in patients with PV.

METHODS

Fourteen patients with PV accompanied by laryngeal or pharyngeal lesions, who underwent flexible laryngeal endoscopy performed by laryngologists, were examined retrospectively.

RESULTS

The arytenoid area was the most frequently affected site in the larynx, followed by the epiglottis and aryepiglottic folds. Vocal folds and ventricular bands were the least affected.

CONCLUSION

Lesions in the arytenoid area were observed more frequently in this study than in previous studies. This result suggests that a more careful inspection of arytenoid lesions in patients with PV is required under laryngeal fiber observation. Moreover, we proposed a novel classification system for laryngeal findings in patients with PV and a systematic observation method. This novel classification and method would be useful not only for determining the lesions but also for careful inspection in this field.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2024.

Natural history of hearing and tumor growth in vestibular schwannoma in neurofibromatosis type 2-related schwannomatosis

OBJECTIVES

To determine the natural history of hearing loss and tumor volume in patients with untreated neurofibromatosis type 2 (NF2)-related schwannomatosis. Moreover, we statistically examined the factors affecting hearing prognosis.

METHODS

This retrospective cohort study was conducted on 37 ears of 24 patients with NF2-related vestibular schwannomatosis followed up without treatment for more than 1 year. We obtained detailed chronological changes in the PTA and tumor volume in each case over time, and the rate of change per year was obtained. Multivariate analysis was also conducted to investigate factors associated with changes in hearing.

RESULTS

The average follow-up period was approximately 9 years, and hearing deteriorated at an average rate of approximately 4 dB/year. The rate of maintaining effective hearing decreased from 30 ears (81%) at the first visit to 19 ears (51%) at the final follow-up. The average rate of change in tumor growth for volume was approximately 686.0 mm3/year. This study revealed that most patients with NF2 experienced deterioration in hearing acuity and tumor growth during the natural course. A correlation was observed between an increase in tumor volume and hearing loss (r = 0.686; p < 0.001).

CONCLUSIONS

Although the hearing preservation rate in NF2 cases is poor with the current treatment methods, many cases exist in which hearing acuity deteriorates, even during the natural course. Patients with an increased tumor volume during the follow-up period were more likely to experience hearing deterioration. Trial registration number 20140242 (date of registration: 27 October 2014).

Fecal DNA analysis coupled with the sighting records re-expanded a known distribution of dugongs in Ryukyu Islands after half a century

DNA analysis of large herbivore feces samples collected from seagrass beds at two distant sites (Irabu Island in Miyako Islands and Kushi in Okinawa Island) in the Ryukyu Islands proved that some of these feces were from dugongs, which had been treated in recent studies as extinct in this region since the last stranding of a deceased individual in 2019. In addition, local knowledge of sightings of animals thought to be dugongs and confirmed cases of dugong feeding trails since 2010 were compiled to estimate its recent distribution. This is the first scientific report on the presence of this mammal in the Ryukyu Islands within the last four years, and particularly in the Miyako Islands within the last half-century. As the Ryukyu Islands are known to be the northern limit of the dugong's fragmented distribution in East Asia, conservation efforts are therefore needed.

Efficacy and safety of the water pressure method for endoscopic submucosal dissection in superficial pharyngeal cancer

Background and study aims Superficial pharyngeal cancers can be cured with transoral surgery (TOS), which preserves organ function and quality of life. Pharyngeal endoscopic submucosal dissection (ESD) is challenging to perform because of limited maneuverability and complex anatomical features. The water pressure method (WPM) is useful for natural traction techniques during ESD and is potentially useful for pharyngeal ESD. This study aimed to investigate the short-term outcomes of WPM-ESD for pharyngeal lesions. Patients and methods Therapeutic outcomes of patients who underwent WPM-ESD for pharyngeal lesions at Keio University between May 2019 and February 2022 were retrospectively analyzed. Results Twenty-one pharyngeal lesions treated with WPM-ESD were analyzed. Three lesions were located in the oropharynx and 18 in the hypopharynx. All ESD procedures were performed under general anesthesia. The endoscopic en bloc resection rate was 100%. The median procedure time was 15 minutes (range 4-45 minutes). All patients were successfully extubated on the day of ESD. No serious adverse events (AEs) related to WPM-ESDs were observed. None of the patients required nasogastric intubation, percutaneous endoscopic gastrostomy, or tracheotomy. The median fasting time and hospital stay were 2 days (range 2-5 days) and 6 days (range 6-10 days), respectively. All the histological results indicated squamous cell carcinoma. The complete histologic resection rate was 76.2%. Conclusions WPM-ESD achieved a high en bloc resection rate and short procedure time without serious AEs. Thus, it may be a useful treatment for pharyngeal lesions.

Characteristics of pure tone audiogram in patients with untreated sporadic vestibular schwannoma: Analysis of audiometric shape and interaural differences stratified by age and mode of onset

OBJECTIVE

Asymmetric sensorineural hearing loss (ASHL) is the most common symptom of sporadic vestibular schwannoma (VS). However, there is still no universally accepted MRI protocol for diagnosing VS. This study identified the characteristics of pure tone audiogram (PTA) in patients with VS.

METHODS

We conducted a retrospective chart review of patients diagnosed with sporadic unilateral VS. In the analysis, we focused on the shape and interaural differences of PTA, stratified by the mode of onset and patient age.

RESULTS

In total, 390 patients met the inclusion criteria. The U-shaped audiogram showed the highest proportion in patients with the onset of sudden sensorineural hearing loss (SSNHL). In patients with SSNHL, U-shaped audiograms were younger than other audiograms, and 86.7 % of patients under 40 had U-shaped audiograms. Patients with VS were more likely to have interaural differences at higher frequencies than at lower frequencies. Patients with SSNHL had a significantly higher percentage of interaural differences at 500-4000 Hz than those with onset other than SSNHL (non-SSNHL patients). In addition, non-SSNHL patients had a significant trend toward a higher percentage of interaural differences at all frequencies with increasing age.

CONCLUSION

MRI screening can be considered in patients with SSNHL with U-shaped audiograms under 40 years of age. In ASHL, not SSNHL, MRI screening can be considered for older patients with interaural differences at wider continuous frequencies. Patients with interaural differences at high frequencies had a higher priority than those with interaural differences at low frequencies as indications for MRI screening for VS.

Brain metastases in patients with salivary duct carcinoma: A retrospective study

BACKGROUND

Salivary duct carcinoma (SDC) is a high-grade adenocarcinoma with a 5-year survival rate of 40%. Although drug therapy has improved patients' prognosis, the impact of brain metastasis (BM) remains poorly understood. We aimed to retrospectively examine the incidence of BM in patients with SDC (n = 464) and develop a tool to estimate their prognoses.

METHODS

We retrospectively examined 464 patients with SDC enrolled in a multicenter study. We investigated the incidence of BM, overall survival (OS) rates, and factors affecting prognosis in patients with BM. We also developed an SDC-graded prognostic assessment (GPA) score for disease prognostication.

RESULTS

Sixty-five (14%) patients had BM. The median OS (mOS) was 13.1 months. On univariate and multivariate analyses, factors such as Eastern Cooperative Oncology Group Performance Status >1, human epidermal growth factor receptor 2-negative status, and locoregional uncontrolled disease were associated with poor OS. SDC-GPA scores according to the prognostic factors were 0, 1, 2, and 3 points, and mOS estimates were 50.5, 16.1, 3.9, and 1.2 months, respectively (p < 0.001).

CONCLUSION

The SDC-GPA score emerged as a useful prognostication tool for patients with BM.

Utility and optimal management of planned drug holidays during lenvatinib treatment in patients with unresectable differentiated thyroid cancer: a real-world multi-center study

PURPOSE

Lenvatinib achieves favorable therapeutic outcomes for patients with radioactive iodine therapy refractory differentiated thyroid cancer (DTC); however, its use is associated with a high incidence of adverse events. To avoid severe adverse events, planned drug holidays (PDH) have been proposed. This study aimed to evaluate treatment effects, identify prognostic factors, and investigate the usefulness of PDH in patients with unresectable DTC who received lenvatinib across the multi-institutions.

METHODS

Fifty-one patients with unresectable DTC treated with lenvatinib were evaluated retrospectively. Overall survival (OS) and progression-free survival (PFS) were calculated, and prognostic factors were assessed. OS, PFS, and time to treatment failure (TTF) were compared between patients with and without PDH. Lenvatinib administration schedule was evaluated in PDH.

RESULTS

The 3-year OS and PFS rate were 53.5% and 42.1%, respectively. Multivariate analysis revealed that presence of maximum size of lung metastasis ≥10 mm was independent prognostic factor for poorer OS and PFS, and histology other than papillary thyroid carcinoma was the independent prognostic factor for poorer PFS. Twenty-five patients (49%) treated with PDH. There were significant differences in OS, PFS, and TTF between patients with and without PDH. Various schedules were used in PDH. Eight (32%) patients required switch to the different administration schedule.

CONCLUSION

Our results suggest that PDHs may extend OS, PFS, and TTF. In patients with PDH, various schedules used for lenvatinib administration highlight the difficulty in determining a uniform administration schedule. Therefore, it is crucial to consider the optimal lenvatinib administration schedule on a case-by-case basis.

Bilateral Deafness Due to Relapsing Polychondritis with Semicircular Canal Calcification Treated With Cochlear Implantation: A Case Report

Relapsing polychondritis (RP) is a rare chronic inflammatory disease characterized by recurrent inflammation of cartilages throughout the body, with treatment-resistant dizziness and hearing loss in 40%-50% of patients with RP. Although rare, severe binaural hearing loss in RP is an indication for cochlear implantation (CI). Therefore, there are only a few reports on CI insertion in cases of RP. This report describes a 68-year-old woman who developed binaural hearing loss due to RP. She was treated with steroids and immunosuppressive drugs; however, her hearing did not improve significantly, and she relied on written communication for conversation. Subsequently, the patient underwent CI in the right ear. The patient showed improvement in speech perception; at 14 months postoperatively, she was able to speak with lipreading, and at 2 years postoperatively, she was able to speak without lipreading. Previous case reports on CI in patients with RP have shown varying degrees of postoperative hearing improvement. Our case demonstrates the effectiveness of CI in improving hearing and speech recognition in patients with RP having semicircular canal calcification. However, previous reports have shown that speech recognition declines 13 years after CI for RP. Therefore, continuous long-term follow-up is necessary.

Effective cochlear implantation for idiopathic hypertrophic pachymeningitis with bilateral profound hearing loss: A case report

RATIONALE

Hypertrophic pachymeningitis (HP) is a local or diffuse fibrous thickness of the dura mater of the brain or spinal cord, caused by infection or connective tissue disease. Headache is the most common clinical symptom, followed by various cranial nerve disorders such as visual impairment, diplopia, and hearing loss. HP can be classified into secondary and idiopathic. Here, we report a case of bilateral progressive profound sensorineural hearing loss diagnosed in a patient with idiopathic HP, where a cochlear implant was effectively used.

PATIENT CONCERNS

The patient was a 77-year-old woman. Hearing loss gradually progressed bilaterally, and magnetic resonance imaging showed a space-occupying lesion with a continuous contrast enhancement in the bilateral internal auditory canals, and diffused dural thickening from the middle to the posterior cranial fossa.

DIAGNOSES

A trans-labyrinthine biopsy was conducted, and a definite diagnosis of idiopathic HP was made. Thickening of the dura mater in the bilateral internal auditory canals was thought to cause profound hearing loss.

INTERVENTIONS AND OUTCOMES

A cochlear implant was implemented 4 months after biopsy, and a favorable hearing response was obtained postoperatively.

LESSONS

This is the first report of a cochlear implant in a patient with idiopathic HP. Cochlear implantation was considered a good treatment for profound hearing loss due to idiopathic HP, which provides a reference for patients to receive timely and correct treatment.

A novel intraoperative continuous monitoring method combining dorsal cochlear nucleus action potentials monitoring with auditory nerve test system

Highly accurate real-time cochlear nerve monitoring to preserve cochlear nerve function is essential for simultaneous cochlear implantation and ipsilateral vestibular schwannoma resection. In the present study, we developed a novel real-time monitoring system that combines dorsal cochlear nucleus action potential monitoring with intracochlear stimulating electrodes (Auditory Nerve Test System, ANTS). We used this system for a case with vestibular schwannoma resection via the translabyrinthine approach. The monitoring system developed in this study detected highly reliable evoked potentials from the cochlear nerve every two seconds continuously during tumor resection. Near-total tumor resection was achieved, and cochlear implantation was performed successfully after confirming the preservation of cochlear nerve function in a case. The patient's hearing was well compensated by cochlear implantation after surgery. Our novel method continuously achieved real-time monitoring of the cochlear nerve every two seconds during vestibular schwannoma resection. The usefulness of this monitoring system for simultaneous tumor resection and cochlear implantation was demonstrated in the present case. The system developed in this study is compatible with continuous facial nerve monitoring. This highly accurate and novel monitoring method will broaden the number of candidates for this type of surgery in the future.

A Case of Vestibular Schwannoma with Deafness Showing Remarkable Hearing Recovery Following Hearing-Preserving Surgery

Surgery for vestibular schwannoma can be divided into hearing-preserving and nonhearing-preserving surgeries. Hearing-preserving surgery is usually not considered in patients with deafness due to vestibular schwannoma, because hearing is unlikely to improve, and surgery aims to maximize the tumor resection at the expense of hearing. We report an extremely rare case of a 46-year-old man with unilateral profound hearing loss due to a vestibular schwannoma with marked cystic degeneration in the left cistern, which significantly recovered to near-normal hearing levels after hearing-preserving surgery. Hearing loss gradually worsened, and preoperative pure-tone evaluation showed complete hearing loss in the left ear. However, the response to the distortion product otoacoustic emission was preserved, and hearing loss was considered to be retrocochlear. Tumor resection was performed using the retrolabyrinthine approach with continuous monitoring using dorsal cochlear nucleus action potential, auditory brainstem response, and facial nerve function muscle action potential. The cistern portion of the tumor was almost completely resected along with the wall. Postoperatively, the pure-tone threshold on the left side markedly improved. The present case clearly demonstrates the possibility of hearing recovery in patients with retrocochlear hearing loss. We should consider expanding the indications for hearing-preserving surgery.

Prognostic value and clinicopathological roles of the tumor immune microenvironment in salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive type of salivary gland carcinoma. Recently, immunotherapies targeting immune checkpoints, including PD1, PD-L1, CTLA4, and LAG3, have had a considerable prognostic impact on various malignant tumors. The implementation of such immune checkpoint inhibitor (ICI) therapies has also been attempted in cases of salivary gland carcinoma. The tumor immune microenvironment (TIME) is implicated in tumorigenesis and tumor progression and is closely associated with the response to ICI therapies. However, the TIME in SDC has not been fully explored. We examined the immunohistochemical expression of CD8, FOXP3, PD1, PD-L1, CTLA4, LAG3, and mismatch repair (MMR) proteins, tumor-infiltrating lymphocytes (TILs), and microsatellite instability (MSI) status in 175 cases of SDC. The associations between these TIME-related markers and the clinicopathological factors and prognosis were evaluated. An elevated expression of CD8, FOXP3, PD1, CTLA4, and LAG3 was associated with more aggressive histological features and an advanced N and/or M classification, elevated Ki-67 index, and poor prognosis. Furthermore, cases with a high PD-L1 expression exhibited more aggressive histological features and adverse clinical outcomes than those with a low expression. Alternatively, there was no significant correlation between TILs and clinicopathological factors. No SDC cases with an MSI-high status or MMR deficiency were found. The coexistence of both an immunostimulatory and immunosuppressive TIME in aggressive SDC might play a role in the presence of T-cell exhaustion. The contribution of multiple immune escape pathways, including regulatory T cells and immune checkpoints, may provide a rationale for ICI therapy, including combined PD1/CTLA4 blockade therapy.

Distribution of macrophages in the developing cochlea of the common marmoset, a primate model animal

Introduction

Macrophages are essential immune cells in the cochlea that contribute to inflammation, tissue repair, and homeostasis. They also play an important role in local cochlear immunity. The developmental immigration and maturation of macrophages in the cochlea have been investigated and are considered essential for normal hearing acquisition. Most of our current knowledge regarding cochlear development is based on rodent models because of the ethical challenges of using human fetal samples for research. However, inter-species differences between rodents and humans have been reported. In this study, we used a primate animal model to investigate the distributions of macrophages in the developing cochlea. The common marmoset (Callithrix jacchus), a small monkey species that inhabits the New World, was used as the model.

Methods

We investigated the distribution of macrophages in the developing cochlea of the common marmoset by performing immunohistochemical analyses of cochlear tissue from common marmoset embryos at different development stages.

Results

We revealed detailed distribution changes in the macrophages of a primate animal model cochlea. This observation indicates that most of the changes in the general distribution of macrophages were well preserved between rodents and this primate. The distribution changes observed in the common marmoset were also compatible with observations in the human fetus; although, observations in the human fetus are limited. Our observations in this study also revealed several differences between common marmosets and rodents.

Conclusion

The time course of immunological development and maturations established in this study will aid in the study of the primate-specific developmental biology of the inner ear. These observations may eventually lead to new therapeutic strategies for hearing loss in humans. In addition, understanding the immunological steady-state of the cochlea may help in the study of age- and genetic-induced hearing loss and in the design of regenerative therapies.

Imaging of Temporal Bone Mass Lesions: A Pictorial Review

Tumoral lesions of the temporal bone include benign or malignant tumors and congenital or inflammatory lesions. Temporal bone lesions are difficult to approach. Therefore, making a preoperative diagnosis and considering whether the lesions require treatment are necessary; if they require treatment, then the type of treatment requires consideration. These tumors cannot be observed directly and must be diagnosed based on symptoms and imaging findings. However, the differentiation of temporal bone lesions is difficult because they are rare and large in variety. In this pictorial review, we divided temporal bone lesions by location such as along the facial nerve, along the internal jugular vein, around the endolymphatic sac, in the internal auditory canal/cerebellopontine angle, petrous apex, middle ear, and mastoid, focusing on the imaging findings of temporal bone lesions. Then, we created a diagnostic flowchart that suggested that the systematic separation of imaging findings is useful for differentiation. Although it is necessary to make comprehensive judgments based on the clinical symptoms, patient background, and imaging findings to diagnose temporal bone mass lesions, capturing imaging features can be a useful differentiation method.

Effectiveness of vocal fold medialization surgery on the swallowing function of patients with unilateral vocal fold paralysis

Objectives

Vocal fold medialization surgery is generally considered a phonosurgical procedure for improvement of vocal function in patients with glottic insufficiency. However, the literature describing this procedure for the management of dysphagia is limited. This study aims to assess the effects of medialization surgery on swallowing function in patients with unilateral vocal fold paralysis (UVFP).

Methods

We enrolled 32 patients with UVFP undergoing vocal fold medialization surgery (medialization laryngoplasty combined with arytenoid adduction [ML + AA], 12 cases; injection laryngoplasty [IL], 20 cases). We assessed the aerodynamic vocal function including maximum phonation time and mean flow rate to evaluate glottal closure status. The Hyodo score determined by flexible endoscopic evaluation and Functional Oral Intake Scale (FOIS) were evaluated pre- and postoperatively.

Results

Almost 60% of patients with UVFP had dysphagia, and one-third were at high risk for aspiration. Aerodynamic parameters effectively improved after IL and ML + AA. With regard to swallowing, both the FOIS and total Hyodo score were significantly improved postoperatively. We found a particularly significant improvement in pharyngeal clearance. However, patients with high vagal nerve paralysis and postoperative insufficient glottal closure showed poor swallowing benefits after the interventions. In patients with recurrent laryngeal nerve palsy, there were no significant differences in postoperative swallowing function between the ML + AA and IL groups.

Conclusion

Vocal fold medialization surgery was effective in improving swallowing function in most cases with UVFP, except for those with high vagal paralysis and insufficient postoperative glottal closure. Both IL and ML + AA showed an equivalent effect on swallowing improvement.

Level of evidence

3b.

Development of cochlear spiral ligament fibrocytes of the common marmoset, a nonhuman model animal

Spiral ligament fibrocytes generate potassium gradients, which hair cells require to convert mechanical sound waves into electrical palsy. Together with the stria vascularis, they regulate endolymph electrolyte homeostasis. Developing spiral ligament fibrocytes and generating endocochlear potential with an appropriate endolymph ion composition are essential for hearing. Understanding spiral ligament fibrocyte development is useful for studying age-related and genetic hearing loss, as well as for regenerative therapy and cochlear immunology. Despite interspecies differences, most studies of cochlear development have been conducted in rodent models due to the difficulty of using human fetal samples. This study investigated the cochlear development of spiral ligament fibrocytes in a small New World monkey species, the common marmoset (Callithrix jacchus). We examined the developmental expression of specific genes in spiral ligament fibrocytes, including those essential for the generation of endolymphatic potential. Our results showed that this animal model of spiral ligament fibrocyte development is similar to that of humans and is a suitable alternative for the analysis of human cochlear development. The time course established in this study will be useful for studying the primate-specific developmental biology of the inner ear, which may lead to novel treatment strategies for human hearing loss.

Mapping of Notch signaling in the developing organ of Corti in common marmosets

Introduction

The well-regulated development of the sensory epithelium is essential for hearing. This process involves the specification of a pro-sensory epithelium containing common progenitors that differentiate into hair and supporting cells. Notch signaling is one of the most critical pathways during these processes, and its modification is thought to be a feasible approach for treating hearing loss. Despite interspecies differences between rodents and primates or humans, most of our current knowledge regarding cochlear development has been obtained from rodent models.

Methods

We therefore examined and mapped the expression patterns of Notch signal components in the developing cochlea of the common marmoset (Callithrix jacchus), a small monkey species native to the New World, a primate model animal.

Results

In contrast to the preserved expression patterns of the Notch signaling components in the hair cell differentiation between primates and rodents, we unveiled relatively large interspecies differences during the maturation of supporting cells.

Discussion

This improved knowledge of Notch signaling during primate cochlear development will facilitate the development of future regenerative therapies.

Apoptosis of type I spiral ganglion neuron cells in Otof-mutant mice

Otof, which encodes otoferlin, knockout mice are considered model mice for auditory neuropathy spectrum disorder, which is characterized by an absent auditory brainstem response (ABR) despite preserved distortion product otoacoustic emission (DPOAE). Although otoferlin-deficient mice lack neurotransmitter release at the inner hair cell (IHC) synapse, it remains unclear how the Otof mutation affects spiral ganglions. Thus, we used Otof-mutant mice carrying the Otof^{tm1a(KOMP)Wtsi} allele (Otof^tm1a) and analyzed spiral ganglion neurons (SGNs) in Otof^tm1a/tm1a mice by immunolabeling type Ⅰ SGNs (SGN-Ⅰ) and type II SGNs (SGN-II). We also examined apoptotic cells in SGNs. Four-week-old Otof^tm1a/tm1a mice had an absent ABR but normal DPOAEs. The number of SGNs was significantly lower in Otof^tm1a/tm1a mice on postnatal day 7 (P7), P14, and P28 compared with that of wild-type mice. Moreover, significantly more apoptotic SGNs were observed in Otof^tm1a/tm1a mice than in wild-type mice on P7, P14, and P28. SGN-IIs were not significantly reduced in Otof^tm1a/tm1a mice on P7, P14, and P28. No apoptotic SGN-IIs were observed under our experimental conditions. In summary, Otof^tm1a/tm1a mice showed a reduction in SGNs accompanied by apoptosis of SGN-Ⅰs even before the onset of hearing. We speculate that the reduction in SGNs with apoptosis is a secondary defect caused by a lack of otoferlin in IHCs. Appropriate glutamatergic synaptic inputs may be important for the survival of SGNs.

Correlation between genotype and phenotype with special attention to hearing in 14 Japanese cases of NF2-related schwannomatosis

NF2-related schwannomatosis (NF2) is an autosomal dominant genetic disorder caused by variants in the NF2 gene. Approximately 50% of NF2 patients inherit pathogenic variants, and the remainder acquire de novo variants. NF2 is characterized by development of bilateral vestibular schwannomas. The genetic background of Japanese NF2 cases has not been fully investigated, and the present report performed a genetic analysis of 14 Japanese NF2 cases and examined genotype-phenotype correlations. DNA samples collected from peripheral blood were analyzed by next-generation sequencing, multiplex ligation-dependent probe amplification analysis, and in vitro electrophoresis. Ten cases had pathogenic or likely pathogenic variants in the NF2 gene, with seven truncating variants and three non-truncating variants. The age of onset in all seven cases with truncating variants was < 20 years. The age of onset significantly differed among cases with truncating NF2 variants, non-truncating NF2 variants, and no NF2 variants. However, the clinical course of tumor growth and hearing deterioration were not predicted only by germline pathogenic NF2 variants. The rate of truncating variants was higher in the present study than that of previous reports. Genotype-phenotype correlations in the age of onset were present in the analyzed Japanese NF2 cases.

Molecular basis of carotid body tumor and associated clinical features in Japan identified by genomic, immunohistochemical, and clinical analyses

Carotid body tumor (CBT) is classified as a paraganglioma (PGL). Here, we report the genetic background, protein expression pattern, and clinical findings of 30 Japanese CBT cases. Germline pathogenic or likely pathogenic (P/LP) variants of genes encoding succinate dehydrogenase subunits (SDHs) were detected in 15 of 30 cases (50%). The SDHB variants were the most frequently detected, followed by SDHA and SDHD variants. One case with SDHAF2 variant was bilateral CBT, and other two multiple PGL cases were not detected P/LP variants. The three cases with germline variants that could be tested did not have somatic P/LP variants of the same genes. Immunohistochemical analysis showed negative SDHB signals in CBT tissues in five cases with germline P/LP variants of SDHB, SDHD, or SDHA. In addition, SDHB signals in CBT tissues were negative in four of nine cases without germline P/LP variants of SDHs. These findings suggest the involvement of unidentified molecular mechanisms affecting SDHs.

Generation of two induced pluripotent stem cell lines from individuals without auditory disorders

We report the establishment of two human induced pluripotent stem cell (iPSC) lines from individuals without auditory disorders. Extensive audiometry tests were performed to confirm normal hearing. The generated iPSC lines expressed pluripotency genes and showed differentiation capability into the three germ layers. The iPSC lines will be used as controls for pathological analysis and drug screening for ear disorders.

Bilobed Flap for Reconstruction of Skin Defects after Excision of Parotid Carcinoma: A Case Report

OBJECTIVES

Local flaps, pedicled flaps, and free flaps are used to reconstruct medium-sized skin defects after excision of parotid carcinoma. The bilobed flap is a local flap primarily used by plastic surgeons for small defects of nasal skin. We report a case of parotid carcinoma with skin infiltration successfully treated by skin reconstruction with a bilobed flap.

METHODS

An 84-year-old man presented with a parotid mass he had noticed 2 months earlier. Parotid carcinoma with skin infiltration was diagnosed and he underwent radical surgery. The skin defect was round (diameter, 6 cm) and was resected and reconstructed with a bilobed flap designed to be caudal to the defect.

RESULTS

Postoperative facial nerve palsy improved within 6 months. The postoperative course was otherwise uneventful, and the patient was discharged on postoperative day 7. Pathological examination revealed a sarcomatoid salivary duct carcinoma.

CONCLUSIONS

Bilobed flaps are useful for reconstructing skin defects with a diameter of 6 cm or less.

Association between atherosclerosis, hearing recovery, and hearing in the healthy ear in idiopathic sudden sensorineural hearing loss: a retrospective chart analysis

Atherosclerosis is reported to be a risk factor for the severity of idiopathic sudden sensorineural hearing loss (ISSNHL). We evaluated the hypothesis that atherosclerosis affects the hearing thresholds of both the affected and healthy sides of ISSNHL patients. We conducted multivariate analyses on retrospectively collected data of patients with ISSNHL (N = 762) to evaluate the relationship between known factors linked to atherosclerosis and hearing thresholds on affected and healthy sides and whether these factors are prognostic for hearing recovery. Older ages, vertigo or dizziness, diabetes mellitus, and congestive heart failure were significantly related to higher hearing thresholds on the affected side. Older ages, male, and vascular disease were significantly related to higher hearing thresholds on the healthy side. Vertigo or dizziness, severe hearing loss and hearing loss at high frequencies on the affected side, higher hearing thresholds on the healthy side, regular anticoagulant medication, and delayed steroid treatment were significantly related to lack of recovery. Since several atherosclerosis-related factors are associated with higher hearing thresholds on both affected and healthy sides in ISSNHL and higher hearing thresholds on the healthy side predict poorer prognosis, diagnosis, and predicting prognosis of ISSNHL may benefit from rigorous evaluation of patients' cardiovascular comorbidities and hearing levels on both the healthy and affected sides.

Development of the stria vascularis in the common marmoset, a primate model

Stria vascularis is a structure that generates potassium gradients in the cochlea, which is vital for hair cells to convert mechanical sound waves into electrical pulses. The precise development of the stria vascularis and subsequent generation of endocochlear potential are thus essential for hearing. Understanding the development of the stria vascularis is valuable for studying hearing loss caused by aging or genetics and designing regenerative therapy. Although inter-species differences have been reported between rodents and humans, most of our current knowledge regarding cochlear development has been obtained from rodent models because of the difficulty in using human fetal samples in this field of research. Therefore, we investigated the development of the cochlear stria vascularis in the common marmoset (Callithrix jacchus), a small monkey species native to the New World. Our study confirms that stria vascularis development in the common marmoset is similar to that in humans and is suitable for furthering our understanding of human cochlear development. The time course established in this report will aid in studying the primate-specific developmental biology of the inner ear, which could eventually lead to new treatment strategies for hearing loss in humans.

Survival benefit of HER2-targeted or androgen deprivation therapy in salivary duct carcinoma

Background

The efficacy and safety of human epidermal growth factor receptor 2 (HER2)-targeted therapy and androgen deprivation therapy (ADT) for locally advanced or recurrent or metastatic (LA/RM) salivary duct carcinoma (SDC) have been reported in prospective studies. However, the survival benefit of these therapies to conventional therapy remains controversial, and whether HER2-targeted therapy or ADT should be chosen in HER2- and androgen receptor (AR)-positive SDC patients remains unknown.

Methods

Overall, 323 LA/RM SDC patients treated at seven institutions between August 1992 and June 2020 were retrospectively enrolled. The primary aim was to analyze the effect of HER2-targeted therapy and ADT on overall survival from the diagnosis of LA/RM disease to death from any cause (OS1). The secondary indicators included the overall response rate (ORR), clinical benefit rate (CBR), overall survival from therapy initiation for LA/RM disease (OS2), progression-free survival (PFS), time to second progression (PFS2), duration of response (DoR), and duration of clinical benefit (DoCB) of HER2-targeted therapy or ADT as first-line therapy for HER2-positive/AR-positive SDC.

Results

Patients treated with HER2-targeted therapy or ADT had longer OS1 than those treated without these therapies (Median OS1: historical control, 21.6 months; HER2-targeted therapy, 50.6 months; ADT, 32.8 months; HER2-targeted therapy followed by ADT, 42.4 months; and ADT followed by HER2-targeted therapy, 45.2 months, p < 0.001). Among HER2-positive/AR-positive SDC patients, although HER2-targeted therapy had better ORR, CBR, and PFS than those of ADT as first-line therapy, we found no significant differences between HER2-targeted therapy and ADT regarding OS2, PFS2, DoR, and DoCB.

Conclusion

Patients treated with HER2-targeted therapy and ADT showed longer survival in LA/RM SDC. HER2-targeted therapy can be recommended prior to ADT for HER2-positive/AR-positive SDC. It is warranted to establish a biomarker that could predict the efficacy of clinical benefit or better response in ADT.

Early-Phase Adverse Effects and Management of Liposomal Amikacin Inhalation for Refractory Mycobacterium avium Complex Lung Disease in Real-World Settings

Purpose

Amikacin liposome inhalation suspension (ALIS), which efficiently allows amikacin to reach the pulmonary periphery for effect while minimising systemic adverse effects, was recently approved for treating Mycobacterium avium complex (MAC) infections. The international Phase 3 open-label clinical trials showed promising results, contributing to sputum culture conversion, but few studies have examined the efficacy and adverse effects of ALIS using real-world data. We identified the clinical outcome and adverse effects of ALIS in the early phase of treatment, for more effective and safe use in clinical practice.

Patients and Methods

The study population consisted of patients with MAC lung disease (MAC-LD), introduced to ALIS therapy after July 2021 at Keio University Hospital due to poor response to multidrug therapy. The sputum smear/culture results, symptoms, adverse effects, and the serum amikacin concentrations of the early phase of ALIS inhalation therapy were examined.

Results

A total of 11 patients (9 women; median age 64.6 years) were included in this study. The median disease duration of MAC-LD was 13.7 years, and all patients exhibited a positive culture at the beginning of ALIS inhalation. Three of the six patients (50.0%) who were initially sputum-smear-positive were confirmed to have become sputum-smear-negative within one month, including one culture conversion. ALIS inhalation therapy caused some adverse effects in nine patients (81.8%); however, no serious systemic adverse effects were observed. The most common adverse effect was hoarseness (72.7%), which mostly occurred around 1 week after initiation. The medians of peak serum amikacin concentrations were 1.4 and 2.3 μg/mL for the first and third inhalations, respectively. Trough serum concentrations just before the third inhalation were <1.2 μg/mL in all patients.

Conclusion

ALIS therapy might be a treatment option for patients with refractory MAC infection with long disease duration and a poor response to guideline-based therapy.

Effects of hearing aids in patients with unilateral tinnitus with acquired ipsilateral sensorineural hearing loss

OBJECTIVES

To evaluate the effectiveness of sound therapy using hearing aids in patients experiencing tinnitus with acquired unilateral sensorineural hearing loss.

METHODS

A total of 97 patients with unilateral tinnitus with acquired ipsilateral sensorineural hearing loss were included. Evaluation involved self-report questionnaires administered at entry, 3 months after treatment, and 1 year after treatment.

RESULTS

The mean Tinnitus Handicap Inventory score before treatment decreased significantly (p < 0.01) at 3 months (50.0 ± 24.5-12.7 ± 16.2), and 1 year (53.3 ± 25.5-8.79 ± 13.9), after treatment. Moreover, the visual analog scale score decreased significantly at 3 months (loudness, 69.6 ± 21.9-29.1 ± 27.2; annoyance, 71.1 ± 24.7-22.7 ± 25.5) and 1 year (loudness, 69.8 ± 22.0-21.1 ± 26.1; annoyance, 72.7 ± 25.6-19.4 ± 27.6). Approximately 80-90% of patients noticed improvements in tinnitus annoyance and loudness, as determined by their responses to the questionnaires of subjective symptom improvement.

CONCLUSIONS

Hearing aids are remarkably effective for patients with unilateral tinnitus with acquired ipsilateral sensorineural hearing loss.

Abstract 5210: Tumor immune characterization identifies age-stratified biomarkers for nivolumab in patients with head and neck squamous cell carcinoma: A nationwide collaborative study in Japan

Background: Biomarkers predicting therapeutic response to immunotherapy have been widely explored via monitoring the liquid and tissue-derived components. Increasing treatment options for recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) mandates prediction of the therapeutic response of anti-PD-1 antibody alone as well as optimization of the treatment sequence. In view of improving biomarkers predicting the efficacy of immunotherapy for R/M HNSCC, we hypothesized that biomarkers can be personalized depending on clinicopathological backgrounds and treatment sequence.

Methods: In this study, we retrospectively included formalin-fixed paraffin-embedded (FFPE) samples, peripheral blood cell counts at treatment, clinicopathological information, and outcome data for patients with R/M HNSCC receiving nivolumab across 22 institutions in Japan (N = 100). FFPE samples were subjected to 14-marker multiplex immunohistochemistry (IHC) and image cytometry analysis (Tsujikawa T et al. Cell Reports, 2017) to quantitatively evaluate CD8+ T cells, helper T cells, regulatory T cells, B cells, natural killer (NK) cells, macrophages, dendritic cells, CD66b+ granulocytes, mast cells, programmed death ligand 1 (PD-L1) and PD-1 expression in a single slide. Intratumoral and circulating immune cell frequencies were comparatively analyzed between responders (CR, n = 14; PR, n = 39) and non-responders (SD, n = 2; PD, n = 45).

Results: Of 100 patients included, responders had significantly lower smoking and alcohol index, higher incidence of immune related adverse events, and higher PD-L1 expression in immune cells as well as PD-L1 combined positive score (CPS) than non-responders. Next, focusing on the history of prior therapy, stratified analysis revealed that the frequency of NK cells was associated with nivolumab response in patients with prior cetuximab use, but not in cetuximab-naïve status. Furthermore, stratified analysis by patient age revealed that nivolumab response was significantly associated with high CPS and lymphoid-inflamed profiles based on cell densities of nine immune cell lineages in the group aged 65 years or older, but not in the group under 65 years of age. On the contrary, the neutrophil/lymphocyte ratios (NLR) in peripheral blood counts at nivolumab treatment were significantly lower in responders (mean 4.96) than those in non-responders (mean 10.46) in the group under 65 years of age, but not in those over 65 years of age (7.41 versus 8.47).

Conclusions: Using peripheral blood data and tumor tissue profiling stratified by patient age and prior treatment might provide better predictive biomarkers in nivolumab response to HNSCC. Further preclinical and clinical studies elucidating immune mechanisms in different patient backgrounds will be warranted.

Citation Format: Takahiro Tsujikawa, Kazuchika Ohno, Sumiyo Saburi, Junichi Mitsuda, Kanako Yoshimura, Alisa Kimura, Hiroki Morimoto, Gaku Ohmura, Akihito Arai, Hiroshi Ogi, Saya Shibata, Yosuke Ariizumi, Akihisa Tasaki, Ryosuke Takahashi, Yumiko Tateishi, Hiroaki Kawabe, Sadakatsu Ikeda, Kei-ichi Morita, Tatsuhiko Tsunoda, Takumi Akashi, Morito Kurata, Issei Imoto, Yasushi Shimizu, Akihito Watanabe, Yukinori Asada, Ryuichi Hayashi, Yuki Saito, Hiroyuki Ozawa, Kiyoaki Tsukahara, Nobuhiko Oridate, Arata Horii, Takashi Maruo, Nobuhiro Hanai, Hidenori Inohara, Hiroshi Iwai, Takashi Fujii, Ken-ichi Nibu, Shigemichi Iwae, Tsutomu Ueda, Ryuji Yasumatsu, Hirohito Umeno, Muneyuki Masuda, Kyoko Itoh, Shigeru Hirano, Takahiro Asakage. Tumor immune characterization identifies age-stratified biomarkers for nivolumab in patients with head and neck squamous cell carcinoma: A nationwide collaborative study in Japan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5210.

Early development of the cochlea of the common marmoset, a non-human primate model

Background

Fine-tuned cochlear development is essential for hearing. Owing to the difficulty in using early human fetal samples, most of our knowledge regarding cochlear development has been obtained from rodents. However, several inter-species differences in cochlear development between rodents and humans have been reported. To bridge these differences, we investigated early otic development of a non-human primate model animal, the common marmoset (Callithrix jacchus).

Methods

We examined 20 genes involved in early cochlear development and described the critical developmental steps for morphogenesis, which have been reported to vary between rodents and marmosets.

Results

The results revealed that several critical genes involved in prosensory epithelium specifications showed higher inter-species differences, suggesting that the molecular process for hair cell lineage acquisition in primates differs considerably from that of rodents. We also observed that the tempo of cochlear development was three times slower in the primate than in rodents.

Conclusions

Our data provide new insights into early cochlear development in primates and humans and imply that the procedures used for manipulating rodent cochlear sensory cells cannot be directly used for the research of primate cells due to the intrinsic inter-species differences in the cell fate determination program.

Utility of computed tomography findings as a predictor of carotid artery invasion by metastatic lymph nodes in head and neck squamous cell carcinoma

PURPOSE

Carotid artery invasion by metastatic lymph nodes in head and neck squamous cell carcinoma (HNSCC) is one of the diagnostic criteria for unresectable tumors. However, to date, the diagnostic criteria for carotid artery invasion have not been well documented. This study investigated the utility of computed tomography (CT) findings as a predictor of carotid artery invasion by metastatic lymph nodes in HNSCC.

METHODS

Twenty-eight patients who had metastatic lymph nodes of HNSCC attached to the carotid artery as seen on CT images before neck dissection from January 2011 to November 2017 were included. Five imaging parameters (angle of contact [AC], length of contact [LC], haziness of the carotid artery wall [HW], size of the lymph node, and involvement of the bifurcation of the carotid artery [IB]) were assessed using CT to predict carotid artery invasion. Furthermore, the utility of the combination of these five parameters was evaluated.

RESULTS

There were significant differences in AC, LC, and IB between patients with and without carotid artery invasion. There were significant differences in all combinations of the two image findings between patients with and without carotid artery invasion. In particular, the combinations of LC and HW, and LC and IB could clearly predict carotid artery invasion.

CONCLUSION

AC, LC, and IB were useful predictors of carotid artery invasion of metastatic lymph nodes in HNSCC. This study is the first to report that IB is a useful predictor of carotid artery invasion in HNSCC.

Cricotracheostomy in a patient with severe kyphosis: A case report

Cricotracheostomy is a useful surgical procedure for opening the airway in cases where conventional tracheotomy is difficult. This is a safe and easy technique involving removal of the anterior portion of the cricoid cartilage. Herein, we report the case of a patient with difficulty in neck extension due to severe kyphosis, who underwent cricotracheostomy. A 65-year-old woman developed dyspnea and was transported to our hospital. SpO2 was 60% (room air) and endotracheal intubation was performed. She was managed on ventilator. However, weaning off the ventilator was difficult, and endotracheal intubation was prolonged. Subsequently, the patient was referred to us for a tracheostomy. The patient was unable to maintain the supine position due to severe kyphosis, and computed tomography revealed that the brachiocephalic artery was running just below the thyroid gland. Therefore, conventional tracheostomy was difficult to perform, and we performed cricotracheostomy instead. After the cricotracheostomy, there were no tracheal problems, such as tracheal stenosis and stomal hemorrhage. Cricotracheostomy can be performed in cases where multiple anatomical difficulties may be faced in the tracheostomy site, as in this case. Furthermore, cricotracheostomy is beneficial for long-term airway management because it causes fewer complications compared to conventional tracheotomy.

Long-Term Outcomes of Endoscopic Cyst Fenestration for Rathke Cleft Cyst

OBJECTIVE

We sought to elucidate the long-term surgical outcomes and incidence of recurrence and reoperation of endoscopic endonasal cyst fenestration for Rathke cleft cyst (RCC).

METHODS

A retrospective review of the chart and operation record of RCC surgical cases between January 2008 and August 2021 at our institution was conducted. Patient characteristics, intraoperative findings, and postoperative follow-up outcomes were evaluated.

RESULTS

A total of 27 patients were analyzed, with a median postoperative follow-up period of 52 months (range, 1-150 months). Preoperative symptoms were visual dysfunction (59%), headache (41%), and pituitary dysfunction (22%). Endoscopic cyst fenestration was performed in all patients. Ten (37%) patients had intraoperative cerebrospinal fluid leakage. Among them, the only patient in whom sellar floor reconstruction was not performed experienced a repair operation due to postoperative cerebrospinal fluid leakage. No patients experienced postoperative hypopituitarism. Preoperative headache, visual dysfunction, and pituitary hormone disorder improved in 73%, 75%, and 67% of patients, respectively. Although postoperative cyst regrowth was observed in 8 patients (30%), no patient experienced worsening or novel symptoms and none required reoperation.

CONCLUSIONS

Patients with a symptomatic RCC can be effectively treated with endoscopic endonasal cyst fenestration. Reversal of the presenting symptoms resulted, including headache, visual dysfunction, and pituitary hormone dysfunction, in the majority of patients. In our series, appropriate reconstruction of the sellar floor reduced the risk of postoperative cerebrospinal fluid leakage without impacting cyst regrowth. This simple technique appears to effectively disrupt cyst progression in most cases, even after a relatively long-term follow-up period.

The Role of the EZH2 and H3K27me3 Expression as a Predictor of Clinical Outcomes in Salivary Duct Carcinoma Patients: A Large-Series Study With Emphasis on the Relevance to the Combined Androgen Blockade and HER2-Targeted Therapy

Objective

Salivary duct carcinoma (SDC) is a highly aggressive and uncommon tumor arising not only de novo but also in pleomorphic adenoma. Androgen receptor (AR)- and HER2-targeted therapy have recently been introduced for SDC as promising treatment options; however, no predictive biomarkers have yet been established. EZH2 and H3K27me3 are closely linked to the development and progression of various cancers, and EZH2 is also expected to be a desirable therapeutic target. We therefore explored the clinicopathological and prognostic implications of EZH2 and H3K27me3 in a large cohort of SDC patients, focusing on their impact on the therapeutic efficacy of AR- or HER2-targeted therapy.

Materials and Methods

The EZH2 and H3K27me3 immunohistochemical expression and EZH2 Y646 gain-of-function mutation status were examined in 226 SDCs, and the relationship with the clinicopathological factors as well as clinical outcomes were evaluated within the three groups depending on the treatment: AR-targeted (combined androgen blockade with leuprorelin acetate and bicalutamide; 89 cases), HER2-targeted (trastuzumab and docetaxel; 42 cases), and conventional therapy (112 cases).

Results

EZH2 and H3K27me3 were variably immunoreactive in most SDCs. A positive correlation was found between the expression of EZH2 and H3K27me3. The EZH2 expression in the SDC component was significantly higher than that in the pre-existing pleomorphic adenoma component. EZH2 Y646 was not identified in any cases. EZH2-high cases more frequently had an advanced clinical stage and aggressive histological features than EZH2-low cases. An EZH2-high status in patients treated with AR-targeted therapy was associated with a significantly shorter progression-free and overall survival as well as a lower objective response rate and clinical benefit rate. In addition, a H3K27me3-high status in patients treated with AR-targeted therapy was related to a shorter overall survival. Conversely, there was no association between the EZH2 and H3K27me3 expression and the clinical outcomes in the conventional or HER2-targeted therapy groups.

Conclusions

A high expression of EZH2 and H3K27me3 in SDC might be a predictor of a poor efficacy of AR-targeted therapy. Our data provide new insights into the role of EZH2 and H3K27me3 in therapeutic strategies for SDC.

Transcanal endoscopic ear surgery for management of ossicular malformation: clinical outcomes of 17 cases

BACKGROUND

In recent years, transcanal endoscopic ear surgery (TEES) is known as an innovative and minimally invasive surgery.

AIMS

To clarify the usefulness of TEES for the ossicular malformation, we performed a retrospective study.

MATERIAL AND METHODS

We examined cases of ossicular malformation performed using TEES at our hospital between April 2015 and April 2020.

RESULTS

The hearing level results were countable for 16 cases. Post-operative hearing levels were significantly improved. Transient nausea, tongue paralysis, and taste disorders were observed; however, no other complications were observed. In 2015-2018, some of the cases required the assistance of a surgical microscope. In contrast, all the cases were performed by TEES after 2019 using a powered device to curve the canal.

CONCLUSIONS AND SIGNIFICANCE

TEES requires considerable training, and the sensation of depth is difficult to acquire. However, this less invasive method is also helpful for ossicular malformation cases.

Analysis of conductive olfactory dysfunction using computational fluid dynamics

Conductive olfactory dysfunction (COD) is caused by an obstruction in the nasal cavity and is characterized by changeable olfaction. COD can occur even when the olfactory cleft is anatomically normal, and therefore, the cause in these cases remains unclear. Herein, we used computational fluid dynamics to examine olfactory cleft airflow with a retrospective cohort study utilizing the cone beam computed tomography scan data of COD patients. By measuring nasal–nasopharynx pressure at maximum flow, we established a cut-off value at which nasal breathing can be differentiated from combined mouth breathing in COD patients. We found that increased nasal resistance led to mouth breathing and that the velocity and flow rate in the olfactory cleft at maximum flow were significantly reduced in COD patients with nasal breathing only compared to healthy olfactory subjects. In addition, we performed a detailed analysis of common morphological abnormalities associated with concha bullosa. Our study provides novel insights into the causes of COD, and therefore, it has important implications for surgical planning of COD, sleep apnea research, assessment of adenoid hyperplasia in children, and sports respiratory physiology.

A Case Report of a Middle Ear Mass Originated From Cartilage-like Tissue Treated With Transcanal Endoscopic Ear Surgery

Middle ear tumors are relatively rare, and among them, the diagnoses of middle ear lesions originating from cartilage-like tissue are even rarer. Use of transcanal endoscopic ear surgery (TEES) has increased in recent years because of its advantages, such as clear visual field and minimally invasive procedure. Here, we report a middle ear mass originating from cartilage-like tissue treated with TEES. A 62-year-old woman presented with progressive right-sided hearing loss. A white mass was revealed through the tympanic membrane, and pure-tone audiometry detected a mean 50.0 dB conductive hearing loss. Computed tomography showed a mass in the tympanic cavity. TEES was performed for diagnosis and treatment. A white translucent tumor was observed intraoperatively, and it was completely resected. Histopathological examination confirmed the diagnosis of a mass originating from degenerated cartilage-like tissue. To the best of our knowledge, this is the first study of a middle ear mass originating from cartilage-like tissue treated with TEES. TEES with its clear visual field and precise techniques was beneficial in treating the middle ear lesions circumscribed in the tympanic cavity.

Neuronal development in the cochlea of a nonhuman primate model, the common marmoset

Precise cochlear neuronal development is vital to hearing ability. Understanding the developmental process of the spiral ganglion is useful for studying hearing loss aimed at aging or regenerative therapy. Although interspecies differences have been reported between rodents and humans, to date, most of our knowledge about the development of cochlear neuronal development has been obtained from rodent models because of the difficulty in using human fetal samples in this field. In this study, we investigated cochlear neuronal development in a small New World monkey species, the common marmoset (Callithrix jacchus). We examined more than 25 genes involved in the neuronal development of the cochlea and described the critical developmental steps of these neurons. We also revealed similarities and differences between previously reported rodent models and this primate animal model. Our results clarified that this animal model of cochlear neuronal development is more similar to humans than rodents and is suitable as an alternative for the analysis of human cochlear development. The time course established in this report will be a useful tool for studying primate‐specific neuronal biology of the inner ear, which could eventually lead to new treatment strategies for human hearing loss.

Trapezius muscle branch of the spinal accessory nerve without penetrating the sternocleidomastoid muscle as a pitfall in neck dissection: prevalence in a Japanese institution and a protocol for the prevention of iatrogenic injury

BACKGROUND

The spinal accessory nerve (SAN) has several anatomical variations, which may be a pitfall in neck dissection (ND). These include the trapezius muscle branch (TB), which stems from the common trunk before entering the sternocleidomastoid muscle (SCM).

AIMS/OBJECTIVES

To investigate the prevalence of this variation and suggest a protocol for preventing unexpected injury of the TB in ND.

MATERIALS AND METHODS

We conducted a retrospective cohort study for 93 patients who had undergone neck dissection (117 sides) without resection of the SCM nor SAN. We recorded the division of the TB after and before penetration of the SCM by the common trunk (penetrating type TB [PTB]) and non-penetrating type TB [NPTB], respectively).

RESULTS

Among NDs, PTB and NPTB were observed in 61 (52%) and 56 (48%) sides, respectively. In the subgroup of 24 cases with bilateral ND, PTB/PTB, NPTB/NPTB, and NPTB/PTB were observed in eight (33%), nine (38%), and seven (29%) cases, respectively. The prevalence of PTB/NPTB did not differ according to age, sex, or laterality.

CONCLUSIONS AND SIGNIFICANCE

NPTB is a common anatomical variation. The presence or absence of a branch from the common trunk must be initially checked to avoid unexpected damage to the TB.

Effectiveness of hearing aids in treating patients with chronic tinnitus with average hearing levels of <30 dBHL and no inconvenience due to hearing loss

BACKGROUND

The effectiveness of hearing aids for tinnitus patients without hearing loss in conversation-comprehension range and inconvenience in daily communication is unknown.

OBJECTIVE

We aimed to evaluate their therapeutic effect.

MATERIALS AND METHODS

We included 91 patients with average hearing levels <30 dBHL. To determine the effects, self-reported questionnaires were used. Data were collected at the entry and 3 months (n = 91) and 1 year (n = 70) after treatment initiation.

RESULTS

All scores (mean ± standard deviation) decreased significantly (p < 0.0001) from before treatment to 3 months and 1 year after treatment: tinnitus handicap inventory score: from 56 ± 21 to 17 ± 17 and 13 ± 15; visual analogue scale (VAS) score for tinnitus loudness: from 71 ± 20 to 31 ± 26 and 28 ± 29; VAS score for tinnitus annoyance: 79 ± 20 to 27 ± 25 and 26 ± 30, respectively. Approximately 90% of patients noticed improvements in tinnitus annoyance and loudness, as determined by the questionnaires regarding subjective symptom improvement.

CONCLUSIONS

Hearing aids may be useful for tinnitus patients without hearing loss and inconvenience in daily communication.

SIGNIFICANCE

Our findings provide a treatment option for tinnitus patients with an average hearing level of <30 dBHL.

Dynamic Spatiotemporal Expression Changes in Connexins of the Developing Primate's Cochlea

Connexins are gap junction components that are essential for acquiring normal hearing ability. Up to 50% of congenital, autosomal-recessive, non-syndromic deafness can be attributed to variants in GJB2, the gene that encodes connexin 26. Gene therapies modifying the expression of connexins are a feasible treatment option for some patients with genetic hearing losses. However, the expression patterns of these proteins in the human fetus are not fully understood due to ethical concerns. Recently, the common marmoset was used as a primate animal model for the human fetus. In this study, we examined the expression patterns of connexin 26 and connexin 30 in the developing cochlea of this primate. Primate-specific spatiotemporal expression changes were revealed, which suggest the existence of primate-specific control of connexin expression patterns and specific functions of these gap junction proteins. Moreover, our results indicate that treatments for connexin-related hearing loss established in rodent models may not be appropriate for human patients, underscoring the importance of testing these treatments in primate models before applying them in human clinical trials.

Pretherapeutic Predictive Factors for Histological High-Grade Parotid Gland Carcinoma

OBJECTIVE

The histological grade of parotid gland carcinoma (PGC) is an important prognostic factor; however, the diagnosis prior to treatment has been challenging to make. This study aimed to investigate whether the pretreatment clinical findings, including hematological inflammatory, nutritional, and immune markers, could predict the histological grade of PGC.

STUDY DESIGN

Retrospective study.

METHODS

We retrospectively enrolled 111 patients with PGC and evaluated the correlation between histological grade and pretreatment clinical findings such as age, sex, tumor staging, facial nerve paralysis, pain or tenderness, adhesion to the surrounding tissues or tumor immobility, and hematological markers.

RESULTS

Sixty patients (54%) were diagnosed with histological high-grade PGC. Univariate analysis revealed that age, T classification, N classification, TNM stage, facial nerve paralysis, adhesion/immobility, C-reactive protein (CRP), and CRP-to-albumin ratio (CAR) were significant predictors of PGC histological grade. On multivariate analysis, high T classification (T3, 4), high N classification (≥1), and elevated CRP (≥0.22 mg/dL) were independent predictors of high-grade PGC.

CONCLUSIONS

Pretreatment T classification, N classification, and CRP are significant predictors of the histological grading of PGC. Our results are useful for treatment planning and obtaining appropriate informed consent from the patients before treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Cyclooxygenase-2 expression is associated with chemoresistance through cancer stemness property in hypopharyngeal carcinoma

Cyclooxygenase-2 (COX-2) is one of the two isoforms of COX, an enzyme that catalyzes the conversion of arachidonic acid to prostaglandins. COX-2 is associated with the progression in various types of cancer, and its expression has been associated with a poor prognosis in head and neck squamous cell carcinoma (HNSCC). Furthermore, COX-2 expression has been associated with resistance to anticancer drugs. However, the precise mechanism of COX-2 for chemoresistance in HNSCC has not been fully elucidated. The present study aimed to investigate the effect of COX-2 on cancer stem cell (CSC) property and to reveal its effect on chemoresistance using in vitro and clinicopathological assays in HNSCC cells and tissues. The current study analyzed the immunohistochemical expression levels of COX-2 and clinicopathological factors using matched samples of pretreatment biopsy and surgical specimens from patients with hypopharyngeal carcinoma who underwent tumor resection with preoperative chemotherapy, including docetaxel. Additionally, the chemoresistance to docetaxel with or without a COX-2 inhibitor (celecoxib) was examined in HNSCC cell lines by MTS assays. To evaluate the association of COX-2 expression with stemness property, the expression levels of CSC-associated genes after exposure to celecoxib were assessed by reverse transcription-quantitative PCR. A sphere formation assay was also performed using ultra-low attachment dishes and microscopic imaging. The immunohistochemical analysis of biopsy specimens revealed a negative association between COX-2 expression in biopsy specimens and the pathological effect of induction chemotherapy in surgical specimens. The cell survival rate under exposure to docetaxel was decreased by the addition of celecoxib. COX-2 inhibition led to downregulation of CSC-associated gene expression and sphere formation. The present findings suggested that COX-2 expression may be associated with chemoresistance through the cancer stemness property, and inhibition of COX-2 may enhance chemo-sensitivity in HNSCC. Therefore, COX-2 may be an attractive target for the treatment of HNSCC.

AB0763 IGG4-RELATED CORONARY PERIARTERITIS: SYSTEMATIC LITERATURE REVIEW WITH OUR CASE SERIES

Background:

Coronary periarteritis is one of the clinical manifestations of IgG4-related disease. It can cause serious conditions such as angina and ruptured aneurysms. Therefore, it is important to recognize the clinical and radiological characteristics, which was little known.

Objectives:

We report four patients with IgG4-related coronary periarteritis with a systematic literature review.

Methods:

We identified four patients with IgG4-related coronary periarteritis at the St. Luke’s International Hospital in Tokyo, Japan from 2014 to 2020. A systematic literature review was conducted for English articles on IgG4-related coronary periarteritis cases with a full text or abstract available. We summarized patient demographics, IgG and IgG4 titers, the site and morphological type of coronary lesion, and other organ involvements.

Results:

Our 4 cases and 38 cases identified by the literature review were assessed. Coronary artery lesions were detected by a coronary CT in all but two cases. Wall thickening was the most common type of the lesion. Moreover, there were 32 (76.1%) patients with other organ involvements. The commonest other lesion was peri-aortitis in 21 (50.0%) patients. In cases with peri-aortitis, IgG and IgG4 titers were significantly higher than those without peri-aortitis (IgG4; 1540 [705.0, 2570.0] vs 246.0 [160.0, 536.3]; p = 0.001, IgG; 3596.5 [2838.3, 4260.0] vs 1779.0 [1288.3, 1992.8]; p =0.040). In addition, 15 (71.4%) patients of them had three or more IgG4 related organ involvements.

Conclusion:

Coronary CT was a useful imaging modality for the diagnosis of IgG4-related coronary periarteritis, and wall thickening was the most common lesion. Moreover, about half cases coexisted with peri-aortitis. Peri-aortitis and other organ involvements should be screened in those with higher IgG and IgG4.

Table 1.

Characteristics of our cases and the literature review cases.

RCA: right coronary artery, LAD: left anterior descending artery, LCx: left circumflex artery

Disclosure of Interests:

None declared

Risk factor for cerebrospinal fluid leak after endoscopic endonasal skull base surgery: a single-center experience

BACKGROUND

One of the major complications in endoscopic endonasal skull base surgery (EESBS) is postoperative cerebrospinal fluid (CSF) leaks. Recently, EESBS has been applied to various skull base diseases as well as more complicated cases influenced by previous treatment with or without various comorbidities.

AIMS/OBJECTIVES

This study aimed to assess the factors that influence the results of postoperative CSF leak after EESBS with mixed patient backgrounds.

MATERIALS AND METHODS

We conducted a retrospective analysis of the clinical records of patients undergoing EESBS in our institution from 2012 to 2017.

RESULTS

Out of a total of 230 cases of EESBS, 11 (4.8%) suffered from postoperative CSF leakage. The rate of CSF leakage for pituitary adenoma, Rathke's cleft cyst, chordoma, and meningioma was 3.5%, 0%, 3.6% and 8.0%, respectively. Multiple variate analysis revealed that repeated surgery (p = .008) and intraoperative CSF leak (p = .044) were significant risk factors for postoperative CSF leakage.

CONCLUSIONS AND SIGNIFICANCE

The rate of postoperative CSF leakage in this study was comparable to previous reports, and repeated surgery may increase postoperative CSF leakage. The surgical strategy for tumor removal as well as skull base reconstruction should be given careful consideration according to tumor pathology and the patient's condition.

Pterygovaginal artery as a target of embolization before endoscopic skull base surgery

BACKGROUND

The pterygovaginal artery (PtVA), a recurrent branch of the internal maxillary artery (IMA), can be a feeder of skull base tumors. Preoperative embolization can help endoscopic resection of hypervascular lesions, which is performed under a narrow surgical space with restricted instrumental maneuverability.

METHODS

We performed preoperative embolization in five cases with hypervascular skull base lesions supplied by the PtVA, four of which were resected via endoscopic endonasal approach. In two cases, selective PtVA embolization through the distal IMA was successfully conducted.

RESULTS

In all the cases, intraoperative bleeding during endoscopic resection was easily controlled. The medial and lateral origins of the PtVA from the IMA were demonstrated by cone-beam CT images reconstructed from three-dimensional rotational angiography, and anastomoses around the eustachian tube and soft palate were visualized by superselective angiography.

CONCLUSIONS

The PtVA embolization can be an effective strategy before endoscopic skull base tumor resection. When embolizing through the PtVA, clinicians should be aware of its anatomical variations and dangerous anastomoses. Understanding the surrounding angioarchitecture by angiographic techniques helps ensure safe embolization.

Angio-anatomical study of the pterygovaginal artery based on cone-beam computed tomography

PURPOSE

To investigate the anatomical characteristics and clinical implications of the pterygovaginal artery (PtVA), a recurrent branch from the distal internal maxillary artery (IMA), which courses through the pterygovaginal canal that connects the pterygopalatine fossa and nasopharynx.

METHODS

Eighty-two patients with 90 sides of cone-beam computed tomography (CBCT) reconstructed from rotational angiography of the external or common carotid artery with a field of view covering the pterygopalatine fossa were retrospectively reviewed. The origin from the IMA, branching type, distribution, and anastomoses was evaluated. The underlying lesions were 36 hypervascular lesions with possible supply from PtVA (17 cavernous sinus arteriovenous fistulas (AVFs), 6 anterior condylar AVFs, and 13 nasopharyngeal, parasellar, or paraclival tumors) and 46 other diseases.

RESULTS

PtVA was identified in 75 sides (83%). It originated from the pterygopalatine segment of the IMA in 45 sides (60%) and from the pterygoid segment in 30 sides (40%). It arose independently (77%), sharing the common trunk with the Vidian artery (15%) or with other branches. It ran posteromedially through the pterygovaginal canal to supply the mucosa over the nasopharyngeal roof, the choanae, and the pharyngeal ostium of the eustachian tube. It anastomosed with the ascending pharyngeal artery (n=37), the accessory meningeal artery (n=7), and the mandibular artery from the petrous internal carotid artery (n=2). It served as a feeder of osseous AVFs and skull base tumors.

CONCLUSION

PtVA was often identified by CBCT even in normal anatomy. Its detailed angio-anatomy could be evaluated in the presence of parasellar or paraclival hypervascular lesions.

Angioarchitecture and Pre-Surgical Embolization of Central Nervous System Solitary Fibrous Tumor/Hemangiopericytoma

Objective

Hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs) have been categorized as the same disease entity, SFT/HPC, since 2016. SFT/HPC is one of the most highly vascularized brain tumors, distinct from meningioma. The angioarchitecture also differs between these tumors. Understanding these differences can help interventionalists perform presurgical embolization more safely and effectively.

Methods

Vascular structures were analyzed in eight patients with central nervous system (CNS) SFT/HPCs, all of whom received presurgical embolization. The type of embolic materials used and the complication rates were compared between the CNS SFT/HPC cases and 39 meningioma cases treated within the same period. Characteristic angiographic features of SFT/HPC were identified, and we present their interpretation and utilization to inform embolization strategies.

Results

Four angiographic features of SFT/HPCs were identified. 1) Persistence of tumor stain and 2) feeders from branches of the internal carotid artery or vertebral artery were observed in all cases, while 3) connecting feeders (highly dilated vessels that originate from branches of other feeder vessels and run along the surface of one tumor compartment to feed another compartment) were observed in five out of eight cases. 4) Finally, an intratumoral arteriovenous shunt was identified in one case. The frequency of liquid embolic material use was significantly higher in SFT/HPC cases than in meningioma cases. No complications were observed in SFT/HPC cases, and all tumors were effectively removed.

Conclusion

The most appropriate presurgical embolization strategies differ between SFT/HPCs and meningiomas depending on the tumor angioarchitecture. A thorough understanding of the vascular anatomy is necessary for safe and effective embolization of SFT/HPCs.