Durability of Titanium Implants Following Type II Thyroplasty for Adductor Type Spasmodic Dysphonia.

OBJECTIVE: To determine the durability of current titanium implants (TI) used in voice improvement surgery for adductor spasmodic dysphonia (ADSD), which is type II thyroplasty (T2T), and identify the effects of their fractures on vocal functions. METHODS: A total of 36 ADSD patients who underwent T2T had the following exams: The CT scans of the larynx were performed 1 year after the surgery to assess the fractures of TI. The improvement in the mean voice handicap index 10 (VHI-10) scores and the success rate between nonfractured (NFR) and fractured (FR) groups were compared. RESULTS: It was indicated that TI was broken in 21 cases (58.3%). In one case (2.7%), a fracture on the part of the bridge that connects both sides of the plates was observed, and fractures at holes placed on the plates in the other 35 cases (55.6%). The mean VHI-10 score improved from 27.2 ± 8.1 to 11.4 ± 7.9 in the NFR group and from 26.3 ± 4.9 to 9.7 ± 7.9 in the FR group. The success rates were 66.6% in the NFR group and 71.5% in the FR group. No statistical difference was observed in the improvement in the mean VHI-10 scores, and the success rate between the two groups. However, two cases resulted in failure in the FR group, whereas no worsened case was observed in the NFR group. CONCLUSION: The current TI used in T2T has low durability and could result in the worsening of vocal symptoms after the surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:3028-3033, 2023.

The Ferret as a Surgical Model for Vocal Fold Scar Creation and Treatment.

OBJECTIVES: To develop a vocal fold (VF) scarring procedure in the ferret, characterize the scars histologically, and test the injectability of the lamina propria (LP). Secondarily, to compare laryngeal anatomy of the ferret with rat and rabbit. MATERIALS AND METHODS: The larynges of 18 male ferrets were prepared by unilateral scarring, and normal larynges from 6 female Wistar rats and 5 male albino rabbits were used for comparative purposes. For scarring, the right VF were electrocauterized, ablating the entire LP. Prior to harvesting the larynges at 4 and 16 weeks, each ferret was re-anesthetized, and in 3 animals, India ink was injected into the LPs of both normal and scarred VFs. RESULTS: Laryngoscopic methods and instrumentation for precise visualization, scarring, and injection were developed. The scarred VFs had reduced hyaluronic acid and increased collagen type I, III, and fibronectin compared with normal VFs. The 2 timepoints (4 and 16 weeks) differed significantly only in collagen type III level (levels were higher at 4 weeks). Injected ink migrated from scarred LP to muscle layer just beneath the scarred tissue 3 hours after injection. CONCLUSION: The ferret is a promising species for creation and experimental treatment of vocal fold scar.

Radiotherapy for T3N0 glottic carcinoma without cord fixation: elective nodal irradiation or not?

BACKGROUND: Although the T3 category has been changed in the sixth edition of the TNM staging system proposed by the Union for International Cancer Control (UICC), the appropriate clinical target volume (CTV) of elective nodal irradiation (ENI) for T3N0 glottic carcinoma without cord fixation, which was formerly treated as a T1-2N0 disease, is not fully discussed. MATERIALS AND METHODS: We retrospectively analyzed 64 patients staged or restaged as T3N0 disease without cord fixation. All patients received irradiation to the primary lesion alone using opposed lateral fields. Surgery was performed in 10 patients without tumor regression after the delivery of 40 Gy. The other 54 patients received a median total dose of 66 Gy. Concurrent chemoradiotherapy (CRT) with low-dose cisplatin and UFT (low-dose CRT) and docetaxel, cisplatin, and 5-fluorouracil (TPF-CRT) were performed in 23 and 19 patients, respectively. RESULTS: Eighteen (28.1%) patients suffered treatment failure; all were recorded as local failure alone. The 5-year local control rates for RT alone, low-dose CRT, and TPF-CRT groups were 51.7%, 61.6%, and 93.8%, respectively (p = 0.027). The 5-year laryngeal preservation rates for RT alone, low-dose CRT, and TPF-CRT groups were 57.4%, 81.6%, and 89.5%, respectively (p = 0.048). CONCLUSIONS: The rate of regional failure was zero when irradiating the primary lesion alone using opposed lateral fields. This treatment technique covers the most level III regions; hence, CTV for ENI should include level III alone.

Voice tuning with new instruments for type II thyroplasty in the treatment of adductor spasmodic dysphonia.

OBJECTIVE: Adductor spasmodic dysphonia is a rare voice disorder characterized by strained and strangled voice quality with intermittent phonatory breaks and adductory vocal fold spasms. Type II thyroplasty differs from previous treatments in that this surgery does not involve any surgical intervention into the laryngeal muscle, nerve or vocal folds. Type II thyroplasty intervenes in the thyroid cartilage, which is unrelated to the lesion. This procedure, conducted with the aim of achieving lateralization of the vocal folds, requires utmost surgical caution due to the extreme delicacy of the surgical site, critically sensitive adjustment, and difficult procedures to maintain the incised cartilages at a correct position. During surgery, the correct separation of the incised cartilage edges with voice monitoring is the most important factor determining surgical success and patient satisfaction. METHODS: We designed new surgical instruments: a thyroid cartilage elevator for undermining the thyroid cartilage, and spacer devices to gauge width while performing voice monitoring. These devices were designed to prevent surgical complications, and to aid in selecting the optimal size of titanium bridges while temporally maintaining a separation during voice monitoring. RESULTS: We designed new surgical instruments, including a thyroid cartilage elevator and spacer devices. Precise surgical procedures and performing voice tuning during surgery with the optimal separation width of the thyroid cartilage are key points for surgical success. CONCLUSION: We introduce the technique of voice tuning using these surgical tools in order to achieve a better outcome with minimal surgical complications.

Bioengineered vocal fold mucosa for voice restoration.

Patients with voice impairment caused by advanced vocal fold (VF) fibrosis or tissue loss have few treatment options. A transplantable, bioengineered VF mucosa would address the individual and societal costs of voice-related communication loss. Such a tissue must be biomechanically capable of aerodynamic-to-acoustic energy transfer and high-frequency vibration and physiologically capable of maintaining a barrier against the airway lumen. We isolated primary human VF fibroblasts and epithelial cells and cocultured them under organotypic conditions. The resulting engineered mucosae showed morphologic features of native tissue, proteome-level evidence of mucosal morphogenesis and emerging extracellular matrix complexity, and rudimentary barrier function in vitro. When grafted into canine larynges ex vivo, the mucosae generated vibratory behavior and acoustic output that were indistinguishable from those of native VF tissue. When grafted into humanized mice in vivo, the mucosae survived and were well tolerated by the human adaptive immune system. This tissue engineering approach has the potential to restore voice function in patients with otherwise untreatable VF mucosal disease.

Videolaryngoscopic assessment of laryngeal edema after arytenoid adduction.

OBJECTIVES/HYPOTHESIS: Arytenoid adduction (AA) as surgical treatment for unilateral vocal fold paralysis (UVFP) is associated with higher morbidity from airway complications due to postoperative laryngeal edema compared with other laryngeal framework surgeries. The aim of this study was to evaluate postoperative laryngeal edema after AA using a new videolaryngoscopic (VL) scoring assessment. STUDY DESIGN: Prospective case series. METHODS: Nineteen patients with UVFP (14 males and five females; mean age, 56 years) who were treated with AA alone or combined with ansa cervicalis (AA/AC) nerve anastomosis or nerve-muscle pedicle (AA/NMP) flap implantation were evaluated. Laryngeal edema was assessed by VL scoring for 10 days postoperatively. Degree of edema was scored in three subsites: the membranous vocal fold, arytenoid mound, and pyriform sinus on the operated side. Statistical significance was defined as P < .05. RESULTS: No patient experienced postoperative airway compromise. Interexaminer reliability was generally high (Spearman r > 0.75). The mean degree of edema increased steadily from postoperative day (POD) 1 to 3, peaking on POD 3 at all subsites. It then declined significantly from POD 3 to 7 (P < .05) and gradually through POD 10. The maximum degree of edema, maximum edema time, and operative time were not correlated significantly at any subsite. Maximum edema time and surgery type (AA vs. AA/AC or AA/NMP) were not correlated at any subsite. CONCLUSIONS: Inter-rater reliability for the proposed VL scoring was significant at all subsites. The VL findings suggest that AA alone or AA combined with reinnervation showed maximum laryngeal edema on POD 3 but added no significant morbidity.

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.

Changes in respiratory function after thyroplastic surgery.

CONCLUSIONS: A certain degree of subclinical extrathoracic airway compromise may ensue after thyroplastic surgery, although none of the patients reported the presence of dyspneic symptoms in their normal daily lives. OBJECTIVES: To determine the effects of thyroplastic surgery on respiratory function and compare them with the improvement of vocal function. PATIENTS AND METHODS: The study included 53 patients; 7 had type I thyroplasty (type I), 9 had arytenoid adduction (AA), 10 had AA with type I, and 27 had AA with neuromuscular pedicle flap implantation (NMP). Phonatory and respiratory functions were measured preoperatively and postoperatively. The presence of dyspnea during daily activities was determined postoperatively. RESULTS: The difference between the pre- and postoperative values was statistically significant in five comparisons. Forced expiratory volume in 1 s/forced expiratory volume (FEV(1%)) in the AA with type I group, FEV(1)/peak expiratory flow rate (PEFR) in the AA group, and PEFR in the three groups (type I, AA, and AA with NMP). Forty-six patients associated with AA were combined for statistical analysis. The differences were statistically significant for FEV(1%), PEFR, and FEV(1)/PEFR. Changes in maximum phonation time (MPT) were found to have a significant correlation with changes in FEV(1)/PEFR. All the patients denied episodes of dyspnea during their normal daily activities.