Tetsuji Sanuki

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.

Overall Evaluation of Effectiveness of Type II Thyroplasty for Adductor Spasmodic Dysphonia

Objective/Hypothesis: To assess the effectiveness of type II thyroplasty with a titanium bridge in adductor spasmodic dysphonia (AdSD).

Three‐Dimensional Endoscopic Mode for Observation of Laryngeal Structures by Helical Computed Tomography

We produced high‐quality three‐dimensional (3D) endoscopic images of the larynx using helical scanning computed tomography. Subjects included two normal volunteers and 10 patients: five with laryngeal cancer, four with unilateral recurrent laryngeal nerve (RLN) palsy, and one with atrophied vocal folds. Two vertically split hemilaryngeal images were displayed together with the oral and tracheal views. Although motion artifacts were seen in four patients, laryngeal structures including the vocal fold, ventricular fold, and ventricle were clearly identified in all subjects. In the patients with cancer, axial images showing the extent of the tumor in each patient provided more information than 3D endoscopic images. In the patients with RLN palsy and atrophied vocal fold, combination of 3D endoscopic and cross‐sectional images offered more diagnostic information than axial images alone.

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.

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.

Effects of type II thyroplasty on adductor spasmodic dysphonia

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.

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

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.

Outcomes of type II thyroplasty for adductor spasmodic dysphonia: analysis of revision and unsatisfactory cases.

Conclusion. The factors responsible for the observed failures can be broken into two major groups: (1) a wrong indication and (2) an inadequate technique to achieve relief from an excessively tight glottal closure. The use of a titanium bridge in place of a silicone shim was found to be essential. Type II thyroplasty can relieve the symptoms of adductor spasmodic dysphonia (AdSD) when implemented with a modern technique using titanium bridges. Objectives. To identify the factor or factors that necessitated revision surgery in type II thyroplasty for AdSD, detailed analytical examinations were made of individual cases with unsatisfactory outcomes. Patients and methods. A retrospective analysis of a case series with follow-up periods of 2–5 years. Results. Ninety AdSD patients underwent type II thyroplasty. The results in one patient were limited because a pathological mechanism other than AdSD was also involved. One patient, a singer, who wanted a more intense voice for singing was dissatisfied with the results. In three patients, the material used for fixation was inadequate. In two other patients, the method of application of the fixative material was found to be insufficient as it did not include both the upper and lower sides.

Surgical tips for type II thyroplasty for adductor spasmodic dysphonia: modified technique after reviewing unsatisfactory cases

Abstract Conclusion: Use of the titanium bridge, both at the top and bottom corners of the incised thyroid cartilage, is essential for success. Most importantly, these procedures should be done with minimal damage to the tissues involved, using fine instruments. Objectives: Type II thyroplasty that aims at lateralization of the vocal folds for spasmodic dysphonia is a type of surgery that requires utmost surgical caution, because of the extremely delicate site for surgical intervention, critically sensitive adjustment, and difficult procedures to maintain the incised cartilages in a correct position. Patients and methods: By means of a postoperative questionnaire and examinations, analyses were made of the relation in each case between the detailed surgical records and the outcomes in terms of subjective complaints, vocal features, and laryngeal as well as aerodynamic findings. Results: It was found that surgical failures or unsatisfactory results arise most frequently from certain clear mechanical faults. The critical procedures that most affected the results included: (1) incision and separation of the thyroid cartilage at the midline; (2) adjustment of separation width for optimal voice; (3) cartilage–perichondrium separation for holding an appropriate titanium bridge; and (4) installation and fixation of titanium bridges.

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.