Takeharu Kanazawa
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Takeharu Kanazawa has a total of 145 co-authors. Here are the top co-authors by number of shared publications:
Yusuke Watanabe
Tokyo Voice Center, International University of Health and Welfare, Tokyo, Japan
10 shared publicationsDaigo Komazawa
Tokyo Voice Center, International University of Health and Welfare, Tokyo, Japan; AKASAKA Voice Health Center, Tokyo, Japan
9 shared publicationsHiroshi Nishino
Department of Otolaryngology-Head and Neck Surgery, Jichi Medical University Hospital, Shimotsuke 329-0498, Japan
8 shared publicationsKiyoshi Misawa
Department of Otolaryngology-Head and Neck Surgery, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan
8 shared publicationsUjimoto Konomi
Tokyo Voice Center, International University of Health and Welfare, Tokyo, Japan; Voice and Dizziness Clinic Futakotamagawa Otolaryngology, Tokyo, Japan
8 shared publicationsMakoto Ito
Department of Otolaryngology-Head and Neck Surgery, Jichi Medical University Hospital, Shimotsuke 329-0498, Japan
6 shared publications
Latest Publications
- 10 December 2025
- Published by Elsevier in Auris Nasus Larynx
- Vol. 53 (1) , 35-40
Surgical outcome of primary hyperparathyroidism and factors correlated with preoperative serum iPTH concentration
- 10 December 2025
- Published by Elsevier in Auris Nasus Larynx
- Vol. 53 (1) , 35-40
Surgical outcome of primary hyperparathyroidism and factors correlated with preoperative serum iPTH concentration
- Open Access
- 16 June 2025
- Published by Elsevier in Journal of Voice
Retrospective Examination of the Prevalence of Laryngeal Microwebs Associated With Benign Vocal Fold Lesions Under Microlaryngosurgery
- 16 June 2025
- Published by Elsevier in Journal of Voice
Open AccessRetrospective Examination of the Prevalence of Laryngeal Microwebs Associated With Benign Vocal Fold Lesions Under Microlaryngosurgery
- 16 January 2025
- Published by Wiley in Journal of Oral Rehabilitation
- Vol. 52 (6) , 753-759
Impact of Swallowing Assessment Using the Hyodo‐Komagane Score on the Severity of Dysphagia and Medical Staff Workload
Background: The goal of dysphagia treatment is to ensure a safe and effective reduction in both dysphagia severity and medical staff workload. Objective: To investigate the correlation of the Hyodo‐Komagane score with dysphagia severity and medical staff workload. Methods: This retrospective cohort study included 96 patients who were referred from other departments for swallowing evaluation from January to April 2021. The correlation between the Hyodo‐Komagane score and dysphagia severity was assessed using the Food Intake LEVEL Scale (FILS) score, and its effect on the reduction in medical staff workload was examined using the feeding assistance level of the referred patients. Results: This study included 96 hospitalised patients, comprising 15 patients with neuromuscular diseases, eight patients with cardiovascular diseases, 12 patients with head and neck diseases (excluding otolaryngological diseases), 34 patients with internal medicine diseases and 27 patients with cerebrovascular diseases, who underwent swallowing evaluation. The FILS score and feeding assistance level significantly improved at discharge compared with that at referral. A significant correlation was observed between the FILS score and feeding assistance level. The Hyodo‐Komagane score was correlated with the feeding assistance level at discharge but not at referral. Conclusion: The Hyodo‐Komagane score may optimise rehabilitation and reduce dysphagia severity and medical staff workload, indicating its useful effect on dysphagia severity and medical staff labour.
- 16 January 2025
- Published by Wiley in Journal of Oral Rehabilitation
- Vol. 52 (6) , 753-759
Impact of Swallowing Assessment Using the Hyodo‐Komagane Score on the Severity of Dysphagia and Medical Staff Workload
Background: The goal of dysphagia treatment is to ensure a safe and effective reduction in both dysphagia severity and medical staff workload. Objective: To investigate the correlation of the Hyodo‐Komagane score with dysphagia severity and medical staff workload. Methods: This retrospective cohort study included 96 patients who were referred from other departments for swallowing evaluation from January to April 2021. The correlation between the Hyodo‐Komagane score and dysphagia severity was assessed using the Food Intake LEVEL Scale (FILS) score, and its effect on the reduction in medical staff workload was examined using the feeding assistance level of the referred patients. Results: This study included 96 hospitalised patients, comprising 15 patients with neuromuscular diseases, eight patients with cardiovascular diseases, 12 patients with head and neck diseases (excluding otolaryngological diseases), 34 patients with internal medicine diseases and 27 patients with cerebrovascular diseases, who underwent swallowing evaluation. The FILS score and feeding assistance level significantly improved at discharge compared with that at referral. A significant correlation was observed between the FILS score and feeding assistance level. The Hyodo‐Komagane score was correlated with the feeding assistance level at discharge but not at referral. Conclusion: The Hyodo‐Komagane score may optimise rehabilitation and reduce dysphagia severity and medical staff workload, indicating its useful effect on dysphagia severity and medical staff labour.
- Open Access
- 1 November 2024
- Published by Wolters Kluwer Health in International Journal of Surgery Case Reports
- Vol. 124 (C) , 110356
Horizontal partial laryngectomy for laryngeal neuroendocrine tumor: A case report
Introduction: Moderately differentiated neuroendocrine tumors of the larynx are rare malignant tumors that arise from the submucosa of the larynx, for which surgery is the first-line treatment. Presentation of case: We report a case of moderately differentiated neuroendocrine tumor of the larynx, in which the patient, a 74-year-old man, experienced long-term palliation but an unfortunate outcome of death owing to metastasis. Laryngeal endoscopic examination revealed an elevated submucosal lesion on the laryngeal surface of the epiglottis. Computed tomography and magnetic resonance imaging showed a tumor-like lesion demonstrating a contrasting effect in the submucosa of the epiglottis. A biopsy revealed a moderately differentiated neuroendocrine tumor (formerly called an atypical carcinoid), and a horizontal partial laryngectomy was performed. The patient had a good postoperative course; however, three years and ten months after surgery, he experienced recurrence in the upper gastrointestinal tract and carcinoid syndrome and died four years and three months after the surgery. Discussion: The prognosis of laryngeal neuroendocrine tumors remains poor. In this case, local control was possible without irradiation because the resection margins were negative on pathological examination. This case report has been reported in line with the SCARE Criteria. Conclusion: Long-term follow-up of this type of tumor is necessary, as distant metastasis is likely to affect prognosis. In addition to surgery, effective adjuvant therapies, including molecular targeted therapies, should be established. Highlights:
- 1 November 2024
- Published by Wolters Kluwer Health in International Journal of Surgery Case Reports
- Vol. 124 (C) , 110356
Open AccessHorizontal partial laryngectomy for laryngeal neuroendocrine tumor: A case report
Introduction: Moderately differentiated neuroendocrine tumors of the larynx are rare malignant tumors that arise from the submucosa of the larynx, for which surgery is the first-line treatment. Presentation of case: We report a case of moderately differentiated neuroendocrine tumor of the larynx, in which the patient, a 74-year-old man, experienced long-term palliation but an unfortunate outcome of death owing to metastasis. Laryngeal endoscopic examination revealed an elevated submucosal lesion on the laryngeal surface of the epiglottis. Computed tomography and magnetic resonance imaging showed a tumor-like lesion demonstrating a contrasting effect in the submucosa of the epiglottis. A biopsy revealed a moderately differentiated neuroendocrine tumor (formerly called an atypical carcinoid), and a horizontal partial laryngectomy was performed. The patient had a good postoperative course; however, three years and ten months after surgery, he experienced recurrence in the upper gastrointestinal tract and carcinoid syndrome and died four years and three months after the surgery. Discussion: The prognosis of laryngeal neuroendocrine tumors remains poor. In this case, local control was possible without irradiation because the resection margins were negative on pathological examination. This case report has been reported in line with the SCARE Criteria. Conclusion: Long-term follow-up of this type of tumor is necessary, as distant metastasis is likely to affect prognosis. In addition to surgery, effective adjuvant therapies, including molecular targeted therapies, should be established. Highlights:
- Open Access
- 1 July 2024
- Published by SAGE Publications in Science Progress
- Vol. 107 (3)
Clinical course and vascular endothelial growth factor signaling system expression in maxillary angiosarcoma: A case report
Maxillary angiosarcoma, an aggressive tumor derived from vascular endothelial cells, is very rare. Recently, antivascular endothelial growth factor (VEGF) therapies have attracted considerable attention. We describe the clinical course of a patient with maxillary angiosarcoma and discuss the expression of VEGF signaling molecules assessed via immunohistological analysis. An 81-year-old man presented with an aggressive tumor in the left maxillary sinus. Biopsy revealed atypical nuclear cell proliferation, and the tumor was suspected to be a sarcoma. The maxillary malignancy was treated using a multidisciplinary approach with a combination of surgery, radiotherapy, and regional chemotherapy. Examination of the specimen obtained in the first surgery revealed maxillary angiosarcoma, found to be positive for CD31, while negative for CD34, D2-40, and factor Ⅷ. Although no pathological residual tumor was observed after the planned wide surgery, cervical lymph node and distant metastases occurred. The patient died 24 months after the first surgery. Staining revealed VEGF receptor (VEGFR) 1, VEGFR2, phosphorylated Ak strain transforming, mitogen-activated protein kinase, and signal transducer and activator of transcription 3 positivity. Although our findings do not indicate that anti-VEGF therapy is beneficial for treating maxillary angiosarcomas, we found that VEGFR signaling pathways were activated in maxillary angiosarcomas similar to angiosarcomas originating at other sites. Herein, we report a case of maxillary angiosarcoma, focused on VEGFR and signaling pathway activation. To our knowledge, this is the first report to describe VEGFR system immunostaining findings in maxillary angiosarcoma.
- 1 July 2024
- Published by SAGE Publications in Science Progress
- Vol. 107 (3)
Open AccessClinical course and vascular endothelial growth factor signaling system expression in maxillary angiosarcoma: A case report
Maxillary angiosarcoma, an aggressive tumor derived from vascular endothelial cells, is very rare. Recently, antivascular endothelial growth factor (VEGF) therapies have attracted considerable attention. We describe the clinical course of a patient with maxillary angiosarcoma and discuss the expression of VEGF signaling molecules assessed via immunohistological analysis. An 81-year-old man presented with an aggressive tumor in the left maxillary sinus. Biopsy revealed atypical nuclear cell proliferation, and the tumor was suspected to be a sarcoma. The maxillary malignancy was treated using a multidisciplinary approach with a combination of surgery, radiotherapy, and regional chemotherapy. Examination of the specimen obtained in the first surgery revealed maxillary angiosarcoma, found to be positive for CD31, while negative for CD34, D2-40, and factor Ⅷ. Although no pathological residual tumor was observed after the planned wide surgery, cervical lymph node and distant metastases occurred. The patient died 24 months after the first surgery. Staining revealed VEGF receptor (VEGFR) 1, VEGFR2, phosphorylated Ak strain transforming, mitogen-activated protein kinase, and signal transducer and activator of transcription 3 positivity. Although our findings do not indicate that anti-VEGF therapy is beneficial for treating maxillary angiosarcomas, we found that VEGFR signaling pathways were activated in maxillary angiosarcomas similar to angiosarcomas originating at other sites. Herein, we report a case of maxillary angiosarcoma, focused on VEGFR and signaling pathway activation. To our knowledge, this is the first report to describe VEGFR system immunostaining findings in maxillary angiosarcoma.
- 1 March 2024
- Published by Elsevier in Journal of Voice
- Vol. 38 (2) , 544.e15-544.e21
Validation of the Japanese Version of the Singing Voice Handicap Index
- 1 March 2024
- Published by Elsevier in Journal of Voice
- Vol. 38 (2) , 544.e15-544.e21
Validation of the Japanese Version of the Singing Voice Handicap Index
- 1 March 2023
- Published by Elsevier in Journal of Voice
- Vol. 37 (2) , 299.e1-299.e8
Analysis of Speech Fundamental Frequencies for Different Tasks in Japanese
- 1 March 2023
- Published by Elsevier in Journal of Voice
- Vol. 37 (2) , 299.e1-299.e8
Analysis of Speech Fundamental Frequencies for Different Tasks in Japanese
- Open Access
- 2 January 2023
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 8 (1) , 177-184
Age‐dependent treatment effect of vocal fold steroid injection for benign vocal fold lesions
Objective:Benign vocal fold lesions (BVFLs) cause voice disorders and impair social life. Recently, office-based vocal fold steroid injection (VFSI) has gained attention as a minimally invasive treatment for BVFLs. This study aimed to analyze the age-dependent treatment effect of VFSI and to clarify the indications for treatment. Methods:In this retrospective cohort study, a total of 83 patients with BVFLs were treated with a similar regimen of VFSI. Three or four months after the injection, age-dependent phonological functions were evaluated. The differences between pre- and post-treatment findings were analyzed using the Wilcoxon matched-pair signed-rank test, and the correlation between patient age and improvement rates were determined by Pearson's correlation coefficient. Results:Improvement in voice handicap index (VHI), which was the primary endpoint, was observed. Subjective and objective voice quality measurements also showed significant improvements. Subgroup analyses revealed that there was no age-related difference in the improvement of voice quality and that there was no improvement in aerodynamic effect in patients over 45 years of age. Conclusion:This study clarified the age-dependent treatment effect of VFSI and provided the important suggestion of establishing indication criteria for BVFLs. The study results provided clarity on the indication criteria of VFSI and served as an important indicator for tailoring treatment to patients' needs.
- 2 January 2023
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 8 (1) , 177-184
Open AccessAge‐dependent treatment effect of vocal fold steroid injection for benign vocal fold lesions
Objective:Benign vocal fold lesions (BVFLs) cause voice disorders and impair social life. Recently, office-based vocal fold steroid injection (VFSI) has gained attention as a minimally invasive treatment for BVFLs. This study aimed to analyze the age-dependent treatment effect of VFSI and to clarify the indications for treatment. Methods:In this retrospective cohort study, a total of 83 patients with BVFLs were treated with a similar regimen of VFSI. Three or four months after the injection, age-dependent phonological functions were evaluated. The differences between pre- and post-treatment findings were analyzed using the Wilcoxon matched-pair signed-rank test, and the correlation between patient age and improvement rates were determined by Pearson's correlation coefficient. Results:Improvement in voice handicap index (VHI), which was the primary endpoint, was observed. Subjective and objective voice quality measurements also showed significant improvements. Subgroup analyses revealed that there was no age-related difference in the improvement of voice quality and that there was no improvement in aerodynamic effect in patients over 45 years of age. Conclusion:This study clarified the age-dependent treatment effect of VFSI and provided the important suggestion of establishing indication criteria for BVFLs. The study results provided clarity on the indication criteria of VFSI and served as an important indicator for tailoring treatment to patients' needs.
- Open Access
- 22 September 2022
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 7 (5) , 1465-1473
Intracordal injection therapy for vocal fold scarring: Steroid versus basic fibroblast growth factor
Objectives Vocal fold scarring is caused by replacement of vocal fold mucosa with fibrous tissue due to repeated inflammation or trauma. It can lead to severe dysphonia. It is currently treated conservatively and with phonosurgery and intracordal injections. Intracordal injection of steroid or basic fibroblast growth factor (bFGF) has been recently found to be useful for treating vocal fold scarring that does not respond to voice therapy. Methods This retrospective study involved the administration of steroid injection and bFGF injection bilaterally under local anesthesia in 16 patients each. Laboratory measurements of voice parameters were performed before and 3-6 months after injection. Results In the steroid injection group, the Voice Handicap Index (VHI) score significantly improved from 57.1 to 40.5, total Grade, Roughness, Breathiness, Asthenia, Strain (tGRBAS) score significantly improved from 4.2 to 2.6, and mean speech fundamental frequency (SFF) increased from 192.5 to 211.4 dB, but there was no improvement in maximum phonation time (MPT) and mean airflow rate (MFR). In the bFGF injection group, significant improvements in the VHI score (from 53.3 to 35.7), MPT (from 16.9 to 21.8 s) and MFR (from 314.6 to 210.5 ml/s) were seen; however, the tGRBAS score did not improve. In addition, the SFF significantly decreased from 178.1 to 160.5 Hz. Conclusion These results suggest that both steroid and bFGF injections are effective for treating vocal fold scarring, with steroids improving voice quality and bFGF improving glottic closure, thereby contributing to improvements in VHI scores. Level of Evidence 4.
- 22 September 2022
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 7 (5) , 1465-1473
Open AccessIntracordal injection therapy for vocal fold scarring: Steroid versus basic fibroblast growth factor
Objectives Vocal fold scarring is caused by replacement of vocal fold mucosa with fibrous tissue due to repeated inflammation or trauma. It can lead to severe dysphonia. It is currently treated conservatively and with phonosurgery and intracordal injections. Intracordal injection of steroid or basic fibroblast growth factor (bFGF) has been recently found to be useful for treating vocal fold scarring that does not respond to voice therapy. Methods This retrospective study involved the administration of steroid injection and bFGF injection bilaterally under local anesthesia in 16 patients each. Laboratory measurements of voice parameters were performed before and 3-6 months after injection. Results In the steroid injection group, the Voice Handicap Index (VHI) score significantly improved from 57.1 to 40.5, total Grade, Roughness, Breathiness, Asthenia, Strain (tGRBAS) score significantly improved from 4.2 to 2.6, and mean speech fundamental frequency (SFF) increased from 192.5 to 211.4 dB, but there was no improvement in maximum phonation time (MPT) and mean airflow rate (MFR). In the bFGF injection group, significant improvements in the VHI score (from 53.3 to 35.7), MPT (from 16.9 to 21.8 s) and MFR (from 314.6 to 210.5 ml/s) were seen; however, the tGRBAS score did not improve. In addition, the SFF significantly decreased from 178.1 to 160.5 Hz. Conclusion These results suggest that both steroid and bFGF injections are effective for treating vocal fold scarring, with steroids improving voice quality and bFGF improving glottic closure, thereby contributing to improvements in VHI scores. Level of Evidence 4.
- Open Access
- 25 May 2022
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 7 (3) , 799-806
Long‐term results and safety of fibroblast growth factor injection for unilateral vocal fold paralysis
Objectives: Treatments for unilateral vocal fold paralysis (UVFP) include conservative voice rehabilitation, vocal fold injection, and laryngeal framework surgery. We proposed basic fibroblast growth factor (bFGF) injection as a potential novel treatment for UVFP and have reported the short‐term results. In this study, we present the long‐term results and safety of vocal fold bFGF injection as a treatment for UVFP.Methods: This retrospective study included 42 patients (25 males and 17 females) with UVFP who were administered a local injection of bFGF. The injection regimen involved injecting FGF (0.5 μg/ml in 0.5 ml per side) into the bilateral vocal folds using a 23‐gauge injection needle. Phonological outcomes were evaluated 6 months and 12 months after the injection.Results: Overall, 26 patients received a single injection of bFGF, six patients received an additional injection, and 10 patients received the additional framework surgery. Maximum phonation time, mean flow rate, pitch range, jitter and shimmer percentages, the total GRBAS (grade, roughness, breathiness, asthenia, strain) score, and voice handicap index scores improved significantly in the long term. In patients who received the additional injection or framework surgery, the effects of bFGF injection were temporary, but did not interfere with the performance of the framework surgery.Conclusion: In total, 42 patients who underwent vocal fold bFGF injections were reviewed. The bFGF injections were effective and safe in the long‐term results for UVFP in the selected cases. Some patients with severe symptoms benefited from the additional framework surgery but not the additional bFGF injection.
- 25 May 2022
- Published by Wiley in Laryngoscope Investigative Otolaryngology
- Vol. 7 (3) , 799-806
Open AccessLong‐term results and safety of fibroblast growth factor injection for unilateral vocal fold paralysis
Objectives: Treatments for unilateral vocal fold paralysis (UVFP) include conservative voice rehabilitation, vocal fold injection, and laryngeal framework surgery. We proposed basic fibroblast growth factor (bFGF) injection as a potential novel treatment for UVFP and have reported the short‐term results. In this study, we present the long‐term results and safety of vocal fold bFGF injection as a treatment for UVFP.Methods: This retrospective study included 42 patients (25 males and 17 females) with UVFP who were administered a local injection of bFGF. The injection regimen involved injecting FGF (0.5 μg/ml in 0.5 ml per side) into the bilateral vocal folds using a 23‐gauge injection needle. Phonological outcomes were evaluated 6 months and 12 months after the injection.Results: Overall, 26 patients received a single injection of bFGF, six patients received an additional injection, and 10 patients received the additional framework surgery. Maximum phonation time, mean flow rate, pitch range, jitter and shimmer percentages, the total GRBAS (grade, roughness, breathiness, asthenia, strain) score, and voice handicap index scores improved significantly in the long term. In patients who received the additional injection or framework surgery, the effects of bFGF injection were temporary, but did not interfere with the performance of the framework surgery.Conclusion: In total, 42 patients who underwent vocal fold bFGF injections were reviewed. The bFGF injections were effective and safe in the long‐term results for UVFP in the selected cases. Some patients with severe symptoms benefited from the additional framework surgery but not the additional bFGF injection.