Yoshihiko Kumai

Immediate Recurrent Laryngeal Nerve Reconstruction and Vocal Outcome

Objective: The objective of this prospective study was to assess the long‐term effects of immediate reconstruction of the recurrent laryngeal nerve (RLN) during thyroid cancer extirpation on postoperative phonatory function.

Nerve-muscle pedicle flap implantation combined with arytenoid adduction

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.

Effects of Long-Term Denervation on the Rat Thyroarytenoid Muscle†

Objectives/Hypothesis: To determine the effects of long‐term denervation on the rat thyroarytenoid (TA) muscle and neuromuscular junctions.

Effects of denervation on neuromuscular junctions in the thyroarytenoid muscle

Objectives/Hypothesis: To evaluate the effects of denervation on muscle fibers and neuromuscular junctions (NMJ) of the rat thyroarytenoid (TA) muscle with a histochemical method to monitor the status of degenerative NMJ.

Effects of a Nerve‐Muscle Pedicle on the Denervated Rat Thyroarytenoid Muscle

Objectives: To evaluate the effects of the nerve‐muscle pedicle (NMP) method on the rat thyroarytenoid (TA) muscle after transection of the recurrent laryngeal nerve (RLN).

Nerve-muscle pedicle implantation facilitates re-innervation of long-term denervated thyroarytenoid muscle in rats

Conclusions: Nerve-muscle pedicle (NMP) implantation was effective in the recovery from atrophic changes in long-term denervated thyroarytenoid (TA) muscle. Re-innervation occurred via the transferred nerve. However, the effectiveness of the NMP method may decline with increasing duration of denervation. Objectives: To evaluate the effects of NMP implantation on long-term denervated rat TA muscle. Materials and methods: Wistar rats (n=105) were divided into two groups in which the left recurrent laryngeal nerve (RLN) was transected without (DNV group) or with (NMP group) subsequent NMP implantation, and subgroups of each group were formed depending on the period after RLN transection (immediate to 48 weeks). In the DNV subgroups, we histologically assessed the area of muscle and the number of neuromuscular junctions. In the NMP subgroups, we performed electromyographic, videolaryngoscopic, and histologic assessments. The muscle area and muscle action potentials were evaluated by comparing the treated and untreated sides. The ratio of the number of nerve terminals to that of acetylcholine receptors was also assessed. Results: The TA muscle area was significantly larger in most of the NMP subgroups compared with the DNV subgroups. Muscle action potentials were present in all NMP animals. All histologic and physiologic assessments revealed degradation as the denervation period in the five NMP subgroups.

Swallowing pressure and pressure profiles in young healthy adults

To measure the swallowing pressure (SP) of normal subjects using a 2.64‐mm‐diameter high‐resolution manometry (HRM) catheter with 36 circumferential sensors.

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

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.

Vocal Outcome After Arytenoid Adduction and Ansa Cervicalis Transfer

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.

The impact of nimodipine administration combined with nerve-muscle pedicle implantation on long-term denervated rat thyroarytenoid muscle†

To evaluate the impact of nimodipineon reinnervation of the long‐term denervated rat thyroarytenoid (TA) muscle following nerve‐muscle pedicle flap (NMP) implantation.