Details of a Researcher - Ozawa, Hiroyuki

Papers - Ozawa, Hiroyuki

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Bilobed flap for reconstruction of skin defects after excision of parotid carcinoma: A case report

Sakamoto K., Ozawa H., Shimoda M., Nakaishi M., Sakanushi A., Matsunobu T., Okubo K., Okada T., Sato Y., Shinden S., Ogawa K.

Journal of Nippon Medical School (Journal of Nippon Medical School) 89 ( 6 ) 606 - 611 2022

ISSN 13454676

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.

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

Yoshida A., Hosoya M., Kanzaki S., Fujioka M., Ozawa H.

Acta Oto-Laryngologica (Acta Oto-Laryngologica) 142 ( 2 ) 154 - 160 2022

ISSN 00016489

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.

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

Kawakita D., Nagao T., Takahashi H., Kano S., Honma Y., Hirai H., Saigusa N., Akazawa K., Tani K., Ojiri H., Tsukahara K., Ozawa H., Okami K., Kondo T., Togashi T., Fushimi C., Shimura T., Shimizu A., Okamoto I., Okada T., Imanishi Y., Watanabe Y., Otsuka K., Sakai A., Ebisumoto K., Sato Y., Yamazaki K., Ueki Y., Hanazawa T., Saito Y., Ando M., Matsuki T., Nakaguro M., Sato Y., Urano M., Utsumi Y., Kohsaka S., Saotome T., Tada Y.

Therapeutic Advances in Medical Oncology (Therapeutic Advances in Medical Oncology) 14 2022

ISSN 17588340

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.

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

Ueno M., Shinden S., Oishi N., Suzuki N., Suzuki D., Ogawa K., Ozawa H.

Ear, Nose and Throat Journal (Ear, Nose and Throat Journal) 2022

ISSN 01455613

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.

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

Morita A., Namkoong H., Yagi K., Asakura T., Hosoya M., Tanaka H., Lee H., Ogawa T., Kusumoto T., Azekawa S., Nakagawara K., Kamata H., Ishii M., Fukunaga K., Ozawa H., Hasegawa N.

Infection and Drug Resistance (Infection and Drug Resistance) 15 4001 - 4011 2022

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.

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Diagnosis and Management of Carotid Body Tumors

Ozawa H.

Practica Oto-Rhino-Laryngologica (Practica Oto-Rhino-Laryngologica) 115 ( 4 ) 259 - 264 2022

ISSN 00326313

With the widespread application of genetic testing in recent years, the pathogenesis of carotid body tumors has been clarified. At present, tumor resection is the only curative treatment, with the high risk of perioperative complications, such as intraoperative hemorrhage, inferior cerebral nerve dysfunction, and cerebral infarction. A multidisciplinary team approach is essential for planning safe surgical resection. In addition, treatment options are limited for cases with unresectable disease, such as those with invasion of adjacent structures and/or distant metastasis. New treatment methods are developing. In the near future, new therapies targeting factors contributing to tumor development, such as SDHx, and tumor progression are expected to be developed.

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Cricotracheostomy in a patient with severe kyphosis: A case report

Kasahara K., Nishiyama T., Shigetomi S., Ikari Y., Matsui Y., Ozawa H.

Ear, Nose and Throat Journal (Ear, Nose and Throat Journal) 2022

ISSN 01455613

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.

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

Yoshida K., Akiyama T., Raz E., Kamamoto D., Ozawa H., Toda M.

Neuroradiology Journal (Neuroradiology Journal) 34 ( 6 ) 676 - 682 2021.12

ISSN 19714009

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.

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

Hosoya M., Fujioka M., Murayama A.Y., Ozawa H., Okano H., Ogawa K.

Developmental Neurobiology (Developmental Neurobiology) 81 ( 8 ) 905 - 938 2021.11

ISSN 19328451

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.

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

Yoshida K., Akiyama T., Raz E., Kamamoto D., Ozawa H., Toda M.

Neuroradiology (Neuroradiology) 63 ( 8 ) 1325 - 1333 2021.08

ISSN 00283940

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.

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Endoscopic Endonasal Management of Pterygopalatine Fossa Tumors

Ozawa H., Sekimizu M., Saito S., Nakamura S., Mikoshiba T., Toda M., Ogawa K.

Journal of Craniofacial Surgery (Journal of Craniofacial Surgery) 32 ( 5 ) E454 - E457 2021.07

ISSN 10492275

Surgical removal of pterygopalatine fossa (PPF) tumors with endoscopic endonasal approach is still challenging. The present study aimed to evaluate our endoscopic endonasal management of PPF tumors based on the tumor pathology and purpose of the surgery. This comprised both a single nostril approach for biopsy and a binostril approach for complete resection of benign and noninfiltrating tumors. Based on this strategy, 12 patients underwent endoscopic endonasal surgery for PPF tumors between 2013 and 2018. The patients' data were analyzed retrospectively to demonstrate the significance of our treatment scheme. The surgery was terminated only after taking a biopsy specimen in 6 patients. Other 6 patients underwent gross total resection or bulk tumor reduction. Final pathological diagnosis was malignant in 6 cases and benign in the remaining 6. Post-operative treatment was needed in 7 patients. Four operations for the 6 patients who underwent either debulking or radical surgery were performed by the binostril approach; while 5 surgeries for the 6 biopsy patients were performed by the single nostril approach. Postoperative complications were tolerable. Endoscopic resection should be adopted preferentially for benign tumors that can be removed in a piecemeal fashion. However, as most malignant tumors were impossible to resect with a negative margin, priority should be given to tumor biopsy using an endoscopic approach, which is less invasive than an open approach, and an appropriate treatment customized to the pathological diagnosis should be administered.

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

Saito S., Ozawa H., Imanishi Y., Sekimizu M., Watanabe Y., Fumihiro I.T.O., Ikari Y., Nakahara N., Kameyama K., Ogawa K.

Oncology Letters (Oncology Letters) 22 ( 1 ) 2021.07

ISSN 17921074

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 expres‑ sion 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 resec‑ tion 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.

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Dynamic spatiotemporal expression changes in connexins of the developing primate’s cochlea

Hosoya M., Fujioka M., Murayama A.Y., Ogawa K., Okano H., Ozawa H.

Genes (Genes) 12 ( 7 ) 2021.07

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, un-derscoring the importance of testing these treatments in primate models before applying them in human clinical trials.

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Endoscopic Endonasal Transinfraturbinate Approach With Nasoseptal Window for Removal of the Pterygopalatine Fossa Tumor

Yamada H., Toda M., Abiko T., Ozawa H., Ogawa K., Yoshida K.

Journal of Craniofacial Surgery (Journal of Craniofacial Surgery) 32 ( 2 ) 716 - 718 2021.03

ISSN 10492275

AbstractRecent advances in endoscopic intranasal technology have allowed for a safe approach to the pterygopalatine fossa lesion. However, we consider that there is still scope of improvement to approach a broader area with better operability and minimal invasiveness. A 51-year-old man underwent endoscopic endonasal surgery due to the recurrence of chordoma at the left pterygopalatine fossa. To access the lower and lateral part of the pterygopalatine fossa, we performed endoscopic endonasal transmaxillary removal via an inferior turbinate incision. During surgery, a wide operative field and good operability could be secured by inserting an endoscope from the right nostril through a window of the nasal septum. Subtotal removal of the tumor was achieved without any complication during the surgery. Endoscopic endonasal transinfraturbinate approach with nasoseptal window was effective in the removal of the pterygopalatine fossa tumor because it is less invasive and provides a good surgical view with better operability.

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Prognostic Value of the Lymphocyte-to-Monocyte Ratio in Patients with Parotid Gland Carcinoma

Mikoshiba T., Ozawa H., Watanabe Y., Sekimizu M., Saito S., Yoshihama K., Nakamura S., Imanishi Y., Kameyama K., Ogawa K.

Laryngoscope (Laryngoscope) 131 ( 3 ) E864 - E869 2021.03

ISSN 0023852X

Objective: Previous studies have evaluated various markers as prognostic predictors in patients with many types of cancers. However, the influence of such factors on the outcomes of patients with parotid gland carcinoma (PGC) is unknown. This study investigated the roles of alternative markers in the prognoses of patients with PGC. Methods: Overall, 101 patients who underwent curative treatment for PGC were retrospectively evaluated, and their 5-year overall and disease-free survival rates were calculated. The prognostic values of clinical and pathologic factors were determined. Results: The 5-year overall and disease-free survival rates were 73.1% and 62.8%, respectively. Multivariate analysis revealed that a low lymphocyte-to-monocyte ratio (LMR), high T classification, high N classification, and perineural invasion were independent predictors of poor prognosis. Conclusions: Thus, we identified LMR as an independent prognostic factor for patients with PGC. Patients with low LMRs who are amenable to treatment may require adjuvant treatment to improve their prognoses. Level of Evidence: 4 Laryngoscope, 131:E864–E869, 2021.

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Transoral Removal of Tumors of the Dorsal Aspect of the Soft Palate: A Technical Note

Nakamura S., Ozawa H., Sekimizu M., Ikari Y., Nakahara N., Saito S., Yoshihama K., Nishiyama Y., Ogawa K.

Laryngoscope (Laryngoscope) 131 ( 9 ) 2011 - 2014 2021

ISSN 0023852X

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A case of sinonasal teratocarcinosarcoma

Ikari Y., Ozawa H., Mikoshiba T., Saito S., Nakahara N., Ito F., Sekimizu M., Kawaida M., Kameyama K., Toda M., Ogawa K.

Practica Oto-Rhino-Laryngologica (Practica Oto-Rhino-Laryngologica) 114 ( 3 ) 203 - 209 2021

ISSN 00326313

Teratocarcinosarcoma is a rare, highly malignant tumor, that occurs mainly in the nasal cavity and paranasal sinuses. The prognosis is poor because the tumor invades the surrounding tissues even from an early stage. We report a case of sinonasal teratocarcinosarcoma that was treated by transnasal endoscopic skull base surgery and radiotherapy. The patient was a 65-year-old man who presented with a 2-month history of recurrent left epistaxis. Examination revealed a mass in the left nasal cavity. Computed tomography (CT) revealed a tumor extending from the left ethmoid sinus to the sphenoid sinus, and bone destruction of the anterior skull base. Magnetic resonance imaging (MRI) revealed intracranial extension of the tumor, but no apparent invasion of the brain parenchyma. Biopsy findings led to the suspicion of olfactory neuroblastoma. Since an olfactory neuroblastoma was suspected by biopsy and the possibility of invasion of the brain parenchyma was low, we performed endoscopic endonasal skull base surgery. The tumor was resected with the bone of the skull base and the dura. The skull base was reconstructed with the skull periosteum, fascia lata, and a nasal septum flap. Postoperative histopathological examination revealed the diagnosis of teratocarcinosarcoma. Therefore, after the surgery, the patient received radiotherapy. One year and ten months after the radiotherapy, metastasis to the left cervical lymph nodes was found, and neck dissection was performed. A follow-up examination at 4 years after the radiotherapy showed no evidence of local recurrence or distant metastases to other organs. It was difficult to confirm the histological diagnosis before surgery, and the diagnosis could be confirmed only by histopathology of the resected tumor specimen. The main treatment modality for teratocarcinosarcoma is surgical excision. However, teratocarcinoma is a highly malignant tumor, and radiotherapy and chemotherapy may be useful in addition to surgery, to obtain a better prognosis.

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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

Sakamoto K., Ozawa H., Shimanuki M., Kida A., Kitama T., Iwabu K., Nakaishi M., Sakanushi A., Matsunobu T., Okubo K., Sato Y., Shinden S., Ogawa K.

Acta Oto-Laryngologica (Acta Oto-Laryngologica) 141 ( 8 ) 825 - 829 2021

ISSN 00016489

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.

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

Ozawa H., Sekimizu M., Saito S., Nakamura S., Mikoshiba T., Watanabe Y., Ikari Y., Toda M., Ogawa K.

Acta Oto-Laryngologica (Acta Oto-Laryngologica) 141 ( 6 ) 621 - 625 2021

ISSN 00016489

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.

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

Suzuki N., Shinden S., Oishi N., Ueno M., Suzuki D., Ogawa K., Ozawa H.

Acta Oto-Laryngologica (Acta Oto-Laryngologica) 141 ( 8 ) 773 - 779 2021

ISSN 00016489

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.

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