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Dive into the research topics where Narihiro Kodama is active.

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Featured researches published by Narihiro Kodama.


Archives of Otolaryngology-head & Neck Surgery | 2010

Nerve-muscle pedicle flap implantation combined with arytenoid adduction

Eiji Yumoto; Tetsuji Sanuki; Yutaka Toya; Narihiro Kodama; Yoshihiko Kumai

OBJECTIVES To describe a new technique of nerve-muscle pedicle (NMP) flap implantation combined with arytenoid adduction (AA) to treat dysphonia due to unilateral vocal fold paralysis and to examine postoperative vocal function. STUDY DESIGN Retrospective review of clinical records. SETTING Tertiary academic center. PATIENTS Twenty-two consecutive patients underwent NMP flap implantation with AA and were followed up short term over a period of 1 to 6 months (mean, 2.9 months) and long term over a period of 7 to 36 months (mean, 21.4 months). INTERVENTIONS An NMP flap was made using an ansa cervicalis branch and a piece of the sternohyoid muscle. A window was opened in the thyroid ala at the level of the vocal fold. Then, AA was performed and the NMP flap was securely implanted onto the thyroarytenoid muscle through the window under microscopic guidance. MAIN OUTCOME MEASURES The maximum phonation time, mean airflow rate, pitch range, and acoustic parameters (jitter, shimmer, and harmonics to noise ratio) were evaluated before surgery and twice after surgery. RESULTS All parameters improved significantly after surgery (P < .01). The measurements for maximum phonation time, mean airflow rate, and harmonics to noise ratio were within normal ranges after surgery. Furthermore, the maximum phonation time and jitter were significantly improved after long-term follow-up compared with early postoperative measurements (P < .01 and P < .05, respectively). CONCLUSIONS Precise harvest of an NMP flap and its placement directly onto the thyroarytenoid muscle combined with AA provided excellent vocal function. The NMP method may have played a certain role in the improvement of postoperative vocal function, although further study with electromyographic examination is required to clarify the innervation status of the thyroarytenoid muscle.


Otolaryngology-Head and Neck Surgery | 2010

Effects of type II thyroplasty on adductor spasmodic dysphonia

Tetsuji Sanuki; Eiji Yumoto; Ryosei Minoda; Narihiro Kodama

Objectives: Type II thyroplasty, or laryngeal framework surgery, is based on the hypothesis that the effect of adductor spasmodic dysphonia (AdSD) on the voice is due to excessively tight closure of the glottis, hampering phonation. Most of the previous, partially effective treatments have aimed to relieve this tight closure, including recurrent laryngeal nerve section or avulsion, extirpation of the adductor muscle, and botulinum toxin injection, which is currently the most popular. The aim of this study was to assess the effects of type II thyroplasty on aerodynamic and acoustic findings in patients with AdSD. Study Design: Case series. Setting: University hospital. Subjects and Methods: Ten patients with AdSD underwent type II thyroplasty between August 2006 and December 2008. Aerodynamic and acoustic analyses were performed prior to and six months after surgery. Mean flow rates (MFRs) and voice efficiency were evaluated with a phonation analyzer. Jitter, shimmer, the harmonics-to-noise ratio (HNR), standard deviation of the fundamental frequency (SDF0), and degree of voice breaks (DVB) were measured from each subjects longest sustained phonation sample of the vowel /a/. Results: Voice efficiency improved significantly after surgery. No significant difference was found in the MFRs between before and after surgery. Jitter, shimmer, HNR, SDF0, and DVB improved significantly after surgery. Conclusions: Treatment of AdSD with type II thyroplasty significantly improved aerodynamic and acoustic findings. The results of this study suggest that type II thyroplasty provides relief from voice strangulation in patients with AdSD.


Journal of Oncology | 2010

The Role of Immediate Recurrent Laryngeal Nerve Reconstruction for Thyroid Cancer Surgery

Tetsuji Sanuki; Eiji Yumoto; Ryosei Minoda; Narihiro Kodama

Unilateral vocal fold paralysis (UVFP) is one of the most serious problems in conducting surgery for thyroid cancer. Different treatments are available for the management of UVFP including intracordal injection, type I thyroplasty, arytenoid adduction, and laryngeal reinnervations. The effects of immediate recurrent laryngeal nerve (RLN) reconstruction during thyroid cancer surgery with or without UVFP before the surgery were evaluated with videostroboscopic, aerodynamic, and perceptual analyses. All subjects experienced postoperative improvements in voice quality. Particularly, aerodynamic analysis showed that the values for all patients entered normal ranges in both patients with and without UVFP before surgery. Immediate RLN reconstruction has the potential to restore a normal or near-normal voice by returning thyroarytenoid muscle tone and bulk seen with vocal fold denervation. Immediate RLN reconstruction is an efficient and effective approach to the management of RLN resection during surgery for thyroid cancer.


Auris Nasus Larynx | 2014

Long-term Voice Handicap Index after type II thyroplasty using titanium bridges for adductor spasmodic dysphonia

Tetsuji Sanuki; Eiji Yumoto; Narihiro Kodama; Ryosei Minoda; Yoshihiko Kumai

OBJECTIVES To determine the long-term functional outcomes of type II thyroplasty using titanium bridges for adductor spasmodic dysphonia (AdSD) by perceptual analysis using the Voice Handicap Index-10 (VHI-10) and by acoustic analysis. METHODS Fifteen patients with AdSD underwent type II thyroplasty using titanium brides between August 2006 and February 2011. VHI-10 scores, a patient-based survey that quantifies a patients perception of his or her vocal handicap, were determined before and at least 2 years after surgery. Concurrent with the VHI-10 evaluation, acoustic parameters were assessed, including jitter, shimmer, harmonic-to-noise ratio (HNR), standard deviation of F0 (SDF0), and degree of voice breaks (DVB). RESULTS The average follow-up interval was 30.1 months. No patient had strangulation of the voice, and all were satisfied with the voice postoperatively. In the perceptual analysis, the mean VHI-10 score improved significantly, from 26.7 to 4.1 two years after surgery. All patients had significantly improved each score of three different aspects of VHI-10, representing improved functional, physical, and emotional well-being. All acoustic parameters improved significantly 2 years after surgery. CONCLUSIONS The treatment of AdSD with type II thyroplasty significantly improved the voice-related quality of life and acoustic parameters 2 years after surgery. The results of the study suggest that type II thyroplasty using titanium bridges provides long-term relief of vocal symptoms in patients with AdSD.


Archives of Otolaryngology-head & Neck Surgery | 2012

Vocal Outcome After Arytenoid Adduction and Ansa Cervicalis Transfer

Megahed M. Hassan; Eiji Yumoto; Yoshihiko Kumai; Tetsuji Sanuki; Narihiro Kodama

OBJECTIVE To evaluate the long-term efficacy of arytenoid adduction (AA) combined with ansa cervicalis-recurrent laryngeal nerve anastomosis (ACN-RLN) in the treatment of unilateral vocal fold paralysis. DESIGN Retrospective review of clinical records. SETTING Institutional practice. PATIENTS Nine patients with severe paralytic dysphonia with large glottal gap were included. Voice outcome was followed up over 24 months postoperatively. One patient did not attend the 24-month evaluation. INTERVENTIONS All patients underwent AA + ACN-RLN. The ansa cervicalis nerve to the sternohyoid muscle was used as the donor nerve. MAIN OUTCOME MEASURES Maximum phonation time (MPT), pitch range, harmonics-to-noise ratio (HNR), and perceptual voice quality were evaluated preoperatively and postoperatively at 1 to 3 months, 6 to 8 months, 12 to 14 months, and 24 months. RESULTS All parameters improved significantly after surgery and continued to improve over the 24-month period. The MPT continued to improve over time (P = .01, P = .006, and P = .001 when comparing the 1- to 3-month evaluation with the 6- to 8-month, 12- to 14-month, and 24-month evaluations, respectively). Also, pitch range and HNR showed significant, steady improvement over the 24-month duration of the study. Perceptual voice quality markedly improved at 24 months compared with the 1- to 3-month, 6- to 8-month, and 12- to 14-month follow-ups (P = .004, P = .005, and P = .02, respectively, for grade overall, and P = .004, P = .008, and P = .02, respectively, for breathiness grade). CONCLUSIONS Treatment with AA + ACN-RLN provides near-normal vocal function in the 24-month follow-up. Therefore, this method could be a successful surgical treatment for severe paralytic dysphonia.


Laryngoscope | 2011

Arytenoid rotation and nerve-muscle pedicle transfer in paralytic dysphonia †

Megahed M. Hassan; Eiji Yumoto; M. Ali Baraka; Tetsuji Sanuki; Narihiro Kodama

Our objective was to evaluate the efficacy of modified nerve‐muscle pedicle (NMP) flap transfer combined with arytenoid adduction (AA) (AA + modified NMP) for treatment of unilateral vocal fold paralysis. The patterns of voice outcome assessed using phonatory function tests and auditory perceptual judgments were followed‐up for 2 years.


Otolaryngology-Head and Neck Surgery | 2015

Laryngeal Reinnervation Featuring Refined Nerve-Muscle Pedicle Implantation Evaluated via Electromyography and Use of Coronal Images:

Tetsuji Sanuki; Eiji Yumoto; Kohei Nishimoto; Narihiro Kodama; Haruka Kodama; Ryosei Minoda

Objective To evaluate the long-term efficacy of laryngeal reinnervation via refined nerve-muscle pedicle (NMP) flap implantation combined with arytenoid adduction to treat unilateral vocal fold paralysis (UVFP), employing laryngeal electromyography (LEMG), coronal imaging, and phonatory function assessment. Study Design Case series with chart review. Setting University hospital. Subjects and Methods We retrospectively reviewed 12 UVFP patients who underwent refined NMP implantation with arytenoid adduction. Videostroboscopy, phonatory functional analysis, LEMG, and coronal imaging were performed before and 2 years after surgery. In LEMG analysis, a 4-point scale was employed to grade motor unit (MU) recruitment: 4+ reflected no recruitment, 3+ greatly decreased recruitment, 2+ moderately decreased recruitment, and 1+ mildly decreased activity, associated with less than the full interference pattern. Coronal images were assessed in terms of differences in thickness and the vertical positions of the vocal folds. Results Phonatory function improved significantly after operation in all patients. In terms of LEMG findings, the preoperative MU recruitment scores were 1+ in no patients, 2+ in 4 patients, 3+ in 1 patient, and 4+ in 7 patients. Postoperative MU recruitment results were 1+ in 6 patients, 2+ in 5 patients, 3+ in 1 patient, and 4+ in no patients. Thinning of the affected fold during phonation was evident preoperatively in 9 of 10 patients. The affected and healthy folds were equal in volume in 4 of 9 patients postoperatively. Conclusion The LEMG findings and coronal imaging suggest that NMP implantation may have enabled successful reinnervation of the laryngeal muscles of UVFP patients.


Archives of Otolaryngology-head & Neck Surgery | 2014

Arytenoid Adduction With Nerve-Muscle Pedicle Transfer vs Arytenoid Adduction With and Without Type I Thyroplasty in Paralytic Dysphonia

Megahed M. Hassan; Eiji Yumoto; Tetsuji Sanuki; Yoshihiko Kumai; Narihiro Kodama; M. Ali Baraka; Hassan Wahba; Nervana G. Hafez; Ahlam Abdel-Salam Nabieh El-Adawy

IMPORTANCE Optimal glottal closure as well as symmetrical vocal fold masses and tensions are essential prerequisites for normal voice production. Successful phonosurgery depends on restoring these prerequisites to achieve long-term improvement. OBJECTIVE To evaluate the efficacy of the laryngeal framework surgical treatments (arytenoid adduction with and without thyroplasty type I [AA ± Th-I]) compared with arytenoid adduction combined with nerve-muscle pedicle flap transfer (AA + NMP) in unilateral vocal fold paralysis. Patterns of voice outcome were compared over a 2-year period. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of clinical records of 22 patients who presented to an institutional practice with severe paralytic dysphonia between March 1999 and December 2008, who received 2 different treatments. Postoperative follow-up was conducted over 2 years. INTERVENTIONS Eleven patients were treated with AA ± Th-I and 11 patients were treated with AA + NMP. MAIN OUTCOMES AND MEASURES Vocal function was evaluated preoperatively and at 3, 12, and 24 months postoperatively. Vocal parameters evaluated were jitter, shimmer, harmonics to noise ratio (HNR), maximum phonation time (MPT), and overall grade and breathiness grade of the Grade-Roughness-Breathiness-Asthenia-Strain (GRBAS) voice scale. The outcomes of voice measurements were compared within each group across time and among the 2 groups at each time point. RESULTS All voice parameters showed initial postoperative improvement in both groups after 3 months. Moreover, the AA + NMP group showed significant steady improvement over the 2-year follow-up, which did not occur in the AA ± Th-I group. In the AA + NMP group, MPT increased from a mean (SD) of 5.4 (2.1) s at preoperative assessment to 21.5 (7.0) s at 24 months; jitter decreased from 8.6% (5.3%) to 1.2% (0.7%); shimmer decreased from 13.1% (6.0%) to 4.0% (1.6%); HNR increased from 3.8 (3.3) to 9.0 (0.8); overall grade of GRBAS decreased from 2.4 (0.9) to 0.2 (0.4); and breathiness grade of GRBAS decreased from 2.0 (1.0) to 0.1 (0.3). CONCLUSIONS AND RELEVANCE Unlike the conventional laryngeal framework surgical treatments, AA + NMP provided long-term voice improvement with nearly normal voice quality. Thus, it can be considered an effective surgical treatment for paralytic dysphonia due to unilateral vocal fold paralysis associated with large glottal gap.


Acta Oto-laryngologica | 2014

Over-adduction of the unaffected vocal fold during phonation in the unilaterally paralyzed larynx

Eiji Yumoto; Tetsuji Sanuki; Ryosei Minoda; Yoshihiko Kumai; Kohei Nishimoto; Narihiro Kodama

Abstract Conclusions: Over-adduction of the unaffected vocal fold may not compensate vocal function in unilateral vocal fold paralysis (UVFP). Objective: To determine whether over-adduction of the unaffected vocal fold has any impact on vocal function in patients with UVFP. Methods: A total of 101 patients with UVFP who underwent three-dimensional computed tomographic (CT) examination of the larynx served as subjects. Three-dimensional endoscopic images together with coronal images during phonation were produced to evaluate over-adduction of the unaffected fold, posterior glottal gap, and differences in the vertical position and thickness between the vocal folds. Maximum phonation time (MPT) and mean airflow rate (MFR) were measured. Results: In all, 47 patients showed over-adduction. Their MPT and MFR were 4.9 ± 2.9 s and 653 ± 504 ml/s, respectively. The remaining 54 did not show over-adduction. Their MPT and MFR were 4.7 ± 2.7 s and 574 ± 384 ml/s, respectively. There were no significant differences in MPT or MFR between the two groups. Of the 47 patients with over-adduction, 9 showed no posterior glottal gap. However, their vocal function was not significantly different from that of 38 patients with posterior glottal gap or from that of 43 patients without over-adduction and having a posterior glottal gap.


Laryngoscope | 2017

Arytenoid adduction combined with nerve-muscle pedicle flap implantation or type I thyroplasty

Narihiro Kodama; Yoshihiko Kumai; Tetsuji Sanuki; Eiji Yumoto

To evaluate vocal function after refined nerve‐muscle pedicle (NMP) flap implantation with arytenoid adduction (AA) compared with type I thyroplasty with AA for patients with unilateral vocal fold paralysis (UVFP) and to evaluate the degree of patient satisfaction following the refined NMP with AA.

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