Type 2 thyroplasty for spasmodic dysphonia: fixation using a titanium bridge

Neurectomy and Myomectomy for Treatment of Spasmodic Dysphonia

Spasmodic dysphonia (SD) is a debilitating neurological disorder affecting the muscles of voice production. Sudden involuntary movements of the vocal folds lead to phonatory breaks and to forced, strained, and strangled voice quality in adductor SD, or breathy breaks in abductor SD. There is currently no cure for spasmodic dysphonia, and the gold standard for treatment is the injection of botulinum toxin in small amounts to the intrinsic laryngeal musculature.1 However, botulinum treatment requires periodic reinjection, produces vocal instability immediately after injection, lacks uniform results among patients, and patients can develop antibodies to botulinum toxin. Long-term or permanent symptom relief would be ideal. We present four patients with adductor and one patient with abductor spasmodic dysphonia who underwent neurectomy and myomectomy for treatment. The mean age was 64 years (age range 45-83). The mean duration of adductor spasmodic dysphonia was 11.8 years. The duration of abductor spasmodic was 4 years. All patients had previously been treated with voice therapy and botulinum toxin A. The mean duration of follow up was 1.7 years. Four patients had subjective and objective improvement after surgery. One patient had subjective improvement.

Comparison of Botulinum Toxin Injections and Type 2 Thyroplasty for Adductor Spasmodic Dysphonia

OBJECTIVES

Injection of botulinum toxin type A (BTX) into intrinsic laryngeal muscles is the current gold standard therapy for adductor spasmodic dysphonia (AdSD). However, a surgical procedure could potentially offer more stable and long-lasting voice quality to AdSD patients. Here, we report the long-term results of type 2 thyroplasty (TP2) with TITANBRIDGE® (Nobelpharma, Tokyo, Japan) compared with those of BTX injections.

METHODS

In total, 73 AdSD patients visited our hospital between August 2018 and February 2022. Patients were provided the option of BTX injections or TP2. They were assessed via the Voice Handicap Index (VHI)-10 before treatments and at scheduled clinical follow-ups at 2, 4, 8, and 12 weeks for BTX and at 4, 12, 26, and 52 weeks for TP2.

RESULTS

Overall, 52 patients selected the BTX injection and had a pre-injection mean VHI-10 score of 27.3 ± 8.8. Following injections, the scores significantly improved to 21.0 ± 11.1, 18.6 ± 11.5, and 19.4 ± 11.7 at 2, 4, and 8 weeks, respectively. There were no significant differences between the pre-injection scores and the 12-week scores (21.5 ± 10.7). Alternately, 32 patients opted to be treated with TP2 and had a pre-treatment mean VHI-10 score of 27.7. All patients reported an improvement in their symptoms. Additionally, the mean VHI-10 score significantly improved to 9.9 ± 7.4 at 52 weeks following treatment. There was a significant difference between the two treatment groups at 12 weeks. Some patients received both treatments.

CONCLUSION

These preliminary results provide important insights into the value of TP2 as a potential permanent treatment for AdSD patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:3443-3448, 2023.

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.

Treatment of relapsing functional and organic dysphonia: a narrative literature review

Information about failure and relapses is critical in deciding whether and how to treat a given condition, as well as during patient counselling before therapy. This paper aims to perform a non-systematic review of relapses and failure of dysphonia treatment in the adult population. Studies on failure and relapses after treatment of benign vocal fold lesions, functional dysphonia and neurogenic dysphonia were analysed. The frequency and the duration of follow-up were heterogeneous, and the management of relapses was reported in only a portion of the studies. Relapses after surgical treatment of benign vocal fold lesions ranged between 1% and 58% of cases, and their management was mainly surgical. Rates of relapse after voice therapy for functional dysphonia and spasmodic dysphonia were 12%-88% and 8%-63%, respectively. Rates of relapse after surgical treatment for unilateral and bilateral vocal fold paralysis were 10%-39% and 6%-25%, respectively; treatment was mainly represented by surgical revision. In conclusion, failure and relapses of functional and organic dysphonias after therapy are not rare, but treatment modalities are seldomly reported. The data from this non-systematic review stresses the need for further research in this area.

Spasmodic dysphonia: An overview of clinical features and treatment options

Spasmodic dysphonia (SD) is considered a rare focal laryngeal dystonia characterized by task-specific voice dysfluency resulting from selective intrinsic laryngeal musculature hyperfunction. Symptoms may be attenuated by a sensory trick. Although SD can be seen at times in generalized dystonia syndrome, it is typically a sporadic phenomenon, and the involvement of the laryngeal adductor muscles is more common than that of the abductor muscles. This research reviews the literature for the pathogenesis, clinical characteristics, treatment options, and current management methods of SD. Technological advances have enabled clinicians to better understand the connection between laryngeal function and dysfunction. Refinements in imaging and genetic investigation techniques have helped better understand the underlying mechanisms of this neurolaryngology disorder. Currently, the standard of care for SD is the symptomatic management of botulinum toxin (BT) chemodenervation. This is supported by a large body of literature attesting to its efficacy in many different research studies, particularly in the uncomplicated adductor form of the disorder. Efforts towards surgical treatment predate the development of BT treatment by a decade, but the long-term efficacy has not been proven and, further research is expected. Symptom relief in patients with abductor SD and dystonia with tremors after surgical and BT treatments and those in patients remains suboptimal.

Titanium bridge modification for type 2 thyroplasty to improve device mechanical & safety performance

OBJECTIVE

Titanium bridges are used to separate the thyroid ala during type 2 thyroplasty for adductor spasmodic dysphonia. Revision surgeries have adventitiously indicated that bridge wing failure occurs in the area of the medial hole in some cases. This study investigated the rate and cause of device malfunctions and developed an improved device.

METHODS

We conducted a questionnaire survey to determine the number of surgeries performed in Japan up to the end of 2014, and to obtain information about revision cases. In addition, damage analyses were performed on the fracture surfaces of recovered titanium bridges through use of scanning electron microscopy (SEM).

RESULTS

Between 2002 and 2014, titanium bridges were used in 385 patients. Revision surgery was performed in 19 cases. Revision surgeries revealed that in 11 cases breakage occurred in the wings of the device in the region of the medial hole. However, such fractures were not associated with any signs of recurrence or any adverse events. SEM analyses of fracture surfaces confirmed that fatigue fractures were caused by repeated bending stress in the area of the medial hole. Based on these results, the shape of the hole was changed from round to oval and the wing thickness was increased to prevent breakage.

CONCLUSIONS

The wings of titanium bridges may break without any associated signs, symptoms or tissue damage. Based on the malfunctions detected and analyses of the devices recovered following malfunction, changes to the specification were made for commercial development of the titanium bridge.

The prevalence and clinical features of spasmodic dysphonia: A review of epidemiological surveys conducted in Japan

OBJECTIVES

Spasmodic dysphonia (SD) is a rare disease and its epidemiological status is unclear. This review aimed to explore the current prevalence and clinical features of SD in Japan.

METHODS

We reviewed Japanese surveys of SD and compared them to surveys reported from other countries. We focused on SD prevalence, clinical features (SD type, sex and age), and treatment modalities.

RESULTS

The SD prevalence in Japan was 3.5-7.0/100,000, similar to that in Rochester (NY, USA) and Iceland. Adductor SD predominated (90-95%) and females were four-fold more likely to be affected than males. Mean age at onset was approximately 30 years in Japan. Several years elapsed from onset to diagnosis. The most frequent treatment was botulinum toxin injection, and surgical intervention, particularly type 2 thyroplasty is becoming more popular.

CONCLUSIONS

Our review demonstrated some differences of clinical features of SD in Japan compared with other countries, such as a greater female predominance and younger age of onset. Many physicians and patients may be unfamiliar with the clinical features of SD leading to delayed of diagnosis. Therefore, we proposed diagnostic criteria to facilitate early diagnosis and an appropriate choice of treatment modalities.

Operative Procedure of Anterior Commissure for Type II Thyroplasty

OBJECTIVE

We reviewed the clinical anatomy of the anterior commissure and examined the effectiveness of a specialized spreader developed for optimal, efficient spreading of the thyroid cartilage in type II thyroplasty.

STUDY DESIGN AND METHODS

The present study was a multicenter retrospective study of patients with spasmodic dysphonia who underwent a primary operation either before or after the introduction of a specialized spreader (in 2008 or 2014, respectively). In these patients, we examined the size of the titanium bridge used, the presence of perforation of the mucosa directly superior to the anterior commissure, and postoperative glottic findings.

RESULTS

The sample comprised 39 and 40 patients who underwent surgery in 2008 and 2014, respectively. The mean size of the titanium bridge used during surgery was significantly smaller in 2014 (2.9 mm) than in 2008 (3.81 mm). Perforation of the laryngeal mucosa occurred in 13 patients in 2008 but occurred in only one patient in 2014. Based on glottic findings, spreading the thyroid cartilage using the specialized spreader was deemed to yield an effective glottic gap.

CONCLUSIONS

In type II thyroplasty, the handling of the anterior commissure is the most important point. It is necessary to split the tendon and to spread the glottis while the tendon is joined with the cartilage. For this purpose, a specialized spreader was made. The use of a specialized spreader renders separation around the anterior commissure unnecessary, enabling minimally invasive spreading of the thyroid cartilage and thereby improving phonation.

Perioperative complications and safety of type II thyroplasty (TPII) for adductor spasmodic dysphonia

Type II thyroplasty (TPII) is one of the surgical options offered in the management of adductor spasmodic dysphonia (AdSD); however, there have been no detailed reports of its safety and associated complications during the perioperative period. Our aim was to assess the complications and safety of TPII. TPII was performed for consecutive 15 patients with AdSD from April 2012 through May 2014. We examined retrospectively the perioperative complications, the degree of surgical invasion, and recovery process from surgery. All patients underwent successful surgery under only local anesthesia. Vocal fold erythema was observed in 14 patients and vocal fold edema in 10 patients; however, all of them showed complete resolution within 1 month. No patient experienced severe complications such as acute airway distress or hemorrhage. Fourteen patients were able to have oral from the 1st postoperative morning, with the remaining patient able to have oral intake from the 2nd postoperative day. In addition, no patient experienced aspiration postoperatively. In conclusion, only minor complications were observed in association with TPII in this study. No dysphagia was observed postoperatively, which is an advantage over other treatments. The results of our study suggest that TPII is a safe surgical treatment for AdSD.

Evaluation of type II thyroplasty on phonatory physiology in an excised canine larynx model

OBJECTIVES/HYPOTHESIS

Type II thyroplasty is an alternative treatment for spasmodic dysphonia, addressing hyperadduction by incising and lateralizing the thyroid cartilage. We quantified the effect of lateralization width on phonatory physiology using excised canine larynges.

METHODS

Normal closure, hyperadduction, and type II thyroplasty (lateralized up to 5 mm at 1-mm increments with hyperadducted arytenoids) were simulated in excised larynges (N = 7). Aerodynamic, acoustic, and videokymographic data were recorded at three subglottal pressures relative to phonation threshold pressure (PTP). One-way repeated measures analysis of variance assessed effect of condition on aerodynamic parameters. Random intercepts linear mixed effects models assessed effects of condition and subglottal pressure on acoustic and videokymographic parameters.

RESULTS

PTP differed across conditions (P < .001). Condition affected percent shimmer (P < .005) but not percent jitter. Both pressure (P < .03) and condition (P < .001) affected fundamental frequency. Pressure affected vibratory amplitude (P < .05) and intrafold phase difference (P < .05). Condition affected phase difference between the vocal folds (P < .001).

CONCLUSIONS

Hyperadduction increased PTP and worsened perturbation compared to normal, with near normal physiology restored with 1-mm lateralization. Further lateralization deteriorated voice quality and increased PTP. Acoustic and videokymographic results indicate that normal physiologic relationships between subglottal pressure and vibration are preserved at optimal lateralization width, but then degrade with further lateralization. The 1-mm optimal width observed here is due to the small canine larynx size. Future human trials would likely demonstrate a greater optimal width, with patient-specific value potentially determined based on larynx size and symptom severity.

LEVEL OF EVIDENCE

NA Laryngoscope, 2016 127:396-404, 2017.

[Investigation of Type I Thyroplasty Using Titanium Implant]

OBJECTIVE

The aim of this study was to describe a new titanium thyroplasty medializing implant and evaluate its usefulness.

MATERIAL AND METHOD

Retrospective study of 9 male patients with severe unilateral vocal fold paralysis after aortic-aneurysm surgery who underwent type I thyoplasty with arytenoid adduction under general anesthesia. Preoperative and postoperative glottal closure and voice function were evaluated by acoustic analysis (Jitter %, Shimmer %, NHR), stroboscopic findings, maximum phonation time, mean airflow rate, voice handicap index and computed tomography findings. These tests were evaluated before and 3 months after surgery.

RESULT

All acoustic parameters improved after surgery. In stroboscopic findings, symmetrical mucosal waves were identified in 3 cases. Maximum phonation time prolonged, mean flow rate decreased and voice handicap index improved. In computed-tomography findings, breakage, deformation, dropped and migration of titanium plate were not identified.

CONCLUSION

In surgery of vocal fold paralyzed patient, it is necessary to reconstruct vocal fold in physiological state at the time of phonation. Using the titanium plate developed for this purpose, all patients obtained good vocal improvement.

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

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.

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.

Defining phonosurgery: a proposal for classification and nomenclature by the Phonosurgery Committee of the European Laryngological Society (ELS)

The term phonosurgery (PS) refers to any operation designed primarily for the improvement or restoration of voice. It is defined by the intended operative goal, which pertains to quality of life rather than its preservation, and informed consent needs to account for this emphasis. Since the aim is improvement or maintenance of vocal function, it is essential to document voice accurately pre-operatively. As important as the surgery itself is a team approach to perioperative care and rehabilitation. Although not a new concept, the PS portfolio of operations continues to grow rapidly, making this one of the most dynamic field in Laryngology. However, this has also led to confusion regarding terminology and classification, with the result that it is presently difficult to compare results between institutions. The aim of this paper is to establish a practical classification system for PS and to thereby establish a common language for reporting results. We propose four groups of operation: vocal fold surgery (VFS), laryngeal framework surgery (LFS), neuromuscular surgery (NHS) and reconstructive surgery (RCS) (for either partial or total laryngeal replacement).