Spasmodic DysphoniaNCT07894172
EMG-Guided Versus Endoscopic-Catheter Botulinum Toxin Injection for Spasmodic Dysphonia
A study testing Intervention A - Electromyography (EMG)-Guided BTX Injection and Intervention B - Endoscopic Catheter BTX Injection in people with Spasmodic Dysphonia, run by Chinese University of Hong Kong.
Trial summary
This randomized, controlled non-inferiority trial will compare two established botulinum toxin injection techniques for adductor spasmodic dysphonia: percutaneous electromyography-guided injection and transnasal endoscopic catheter-guided injection. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Spasmodic Dysphonia
- What is being tested?
- Intervention A - Electromyography (EMG)-Guided BTX Injection and Intervention B - Endoscopic Catheter BTX Injection
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 17 participants
- Where
- No sites listed yet
- Study dates
- 21 Oct 2026to 30 Jun 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18 years or older
- Known diagnosis of adductor spasmodic dysphonia (AdSD), who has previously received ≥1 course of BTX injection for AdSD with symptomatic benefit
- Able to independently provide informed consent
- Able to tolerate flexible laryngoscopy
Who cannot join
- Age under 18 years
- Inability to provide independent informed consent
- Known hypersensitivity or allergy to botulinum toxin preparation or to local anaesthetics
- Documented neuromuscular junction disease (e.g. myasthenia gravis, Eaton-Lambert syndrome)
- Unable to tolerate flexible laryngoscopy
- Active laryngeal pathologies other than AdSD requiring concurrent treatment
- Uncorrected coagulopathy or bleeding tendency
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Randomized Controlled Trial of EMG-Guided Versus Endoscopic-Catheter Botulinum Toxin Injection for Spasmodic Dysphonia
This randomized, controlled non-inferiority trial will compare two established botulinum toxin injection techniques for adductor spasmodic dysphonia: percutaneous electromyography-guided injection and transnasal endoscopic catheter-guided injection. The study will evaluate whether the endoscopic technique provides voice outcomes that are not inferior to the standard EMG-guided approach, while also assessing treatment-related adverse effects, procedural tolerability, and practical advantages such as direct visualization and suitability for patients with challenging neck anatomy.
Read the detailed description
Spasmodic dysphonia (SD) is a rare neurological disorder caused by involuntary and intermittent spasms of intrinsic laryngeal muscles. Depending on the intrinsic muscles involved, SD is typically classified into 3 types: Adductor SD (AdSD), abductor SD (AbSD), and mixed SD. AdSD is the most common form of SD, and is a task-specific laryngeal dystonia involving the thyroarytenoid (TA) and lateral cricoarytenoid (LCA) muscles during phonation, resulting in a strained, strangled, and effortful voice with intermittent voice breaks. Symptoms typically first manifest in the mid-30s and may persist as a lifelong condition.
While there is no cure for AdSD and high rate of long term failure with surgical treatment, botulinum toxin (BTX) injection into the TA muscles has been established as the gold-standard treatment for AdSD since the 1980s, with a success rate in voice symptoms improvement up to 90%. BTX blocks acetylcholine release at the neuromuscular junction, producing reversible chemodenervation of the hyperactive intrinsic laryngeal musculature. Relief typically commences within a few days post-injection, with voice improvement lasting approximately 3-4 months before symptom recurrence, requiring repeated injections.
Several techniques have been developed over the years for the administration of BTX into the adductor compartment. The well-established percutaneous electromyography (EMG)-guided approach targets the TA/LCA complex in a transcricothyroid manner, where a needle is introduced through the cricothyroid membrane under real-time EMG feedback and allows confirmation of correct muscle placement during phonation. With the advancements of surgical endoscopes, the endoscopic-catheter injection approach has been a recently described technique also favoured by many surgeons. It is performed transnasally using flexible laryngoscopes, allowing for direct visual confirmation of needle placement into the TA/LCA muscle and false cord via a working-channel catheter.
Proposed benefits of the transnasal endoscopic-catheter approach include the ability to divide BTX injections into sub-doses targeting TA/LCA muscles and false cords, instead of injecting as a whole block as in the EMG-guided approach, potentially producing less breathiness as less total dosage is administered on any one TA muscle. Additionally, it might be particularly useful in cases with anatomical limitations, such as those with non-palpable neck landmarks or poor neck exposure with difficulty/inability in neck extension.
Despite the widespread use of both methods, no randomized controlled trial has directly compared their functional outcomes in a rigorous non-inferiority framework. Previous prospective trials have compared the EMG-guided approach to other methods such as the "point-touch" approach or the endoscopic-guided percutaneous injection approach , showing similar effectiveness amongst these techniques. However, no previous studies have compared the EMG-guided approach to the transnasal endoscopic-catheter approach. It is therefore important to establish non-inferiority of the transnasal endoscopic-catheter approach and capture the comparative advantages and limitations of the two techniques under a randomised and controlled trial setting.
- Conditions
- Spasmodic Dysphonia
- Being tested
- Intervention A - Electromyography (EMG)-Guided BTX Injection, Intervention B - Endoscopic Catheter BTX Injection
- Medical subject headings
- Dysphonia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intervention A - Electromyography (EMG)-Guided BTX InjectionProcedure or surgery
The patient is positioned comfortably with the neck slightly extended. Surface reference and ground electrodes are applied. After application of EMLA cream (lidocaine 2.5%/prilocaine 2.5%) and disinfection of the skin, a 27-gauge needle electrode connected to an EMG machine is introduced percutaneously through the midline of the cricothyroid membrane and angled superiorly and laterally toward the TA muscle. Correct placement is confirmed by characteristic bursts of motor unit activity on phonation. Once confirmed, BTX is injected. The whole procedure including post-operative observation takes approximately 90 minutes. Vital signs and oxygen saturations are monitored throughout the procedure.
Intervention B - Endoscopic Catheter BTX InjectionProcedure or surgery
Following administration of topical anesthesia with 5% lidocaine/0.5% phenylephrine (Co-phenylcaine) nasal spray and topical Xylocaine laryngeal spray via working channel, a transnasal channel flexible bronchoscope is introduced. A sterile catheter needle is introduced via the working channel of the bronchoscope, and BTX is injected directly into the TA/LCA muscle and false cord under direct visualization. The whole procedure including post-operative observation takes approximately 90 minutes. Vital signs and oxygen saturations are monitored throughout the procedure.
| Study group | Role | What they receive |
|---|---|---|
| Arm EMG | Active comparator | Arm EMG: Each participant will receive Intervention A (EMG-guided injection) at Week 0; then a washout period of 14 weeks; and finally followed by Intervention B (endoscopic catheter injection) Crossover injection (opposite intervention) at Week 14. Receives: Procedure: Intervention A - Electromyography (EMG)-Guided BTX Injection; Procedure: Intervention B - Endoscopic Catheter BTX Injection |
| Arm endoscopic catheter | Active comparator | Arm endoscopic catheter : Each participant will receive Intervention B (endoscopic catheter injection) at Week 0; then a washout period of 14 weeks; and finally followed by Intervention A (EMG-guided injection) Crossover injection (opposite intervention) at Week 14. Receives: Procedure: Intervention A - Electromyography (EMG)-Guided BTX Injection; Procedure: Intervention B - Endoscopic Catheter BTX Injection |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from Baseline in Voice Handicap Index (VHI-30) at 4 weeks post-operation
The Voice Handicap Index (VHI-30) is a 30-item self-administered patient-reported outcome measure for voice-related disability, comprising physical, functional, and emotional subscales. In a scale of 0 (Never), 1 (Seldom), 2 (Occasionally), 3 (Frequently) and 4 (Always). Score range 0-120; higher scores indicate greater handicap. Baseline total score of Voice Handicap Index (VHI-30) will be subtracted from 4-week post-operative total score.
Measured: Baseline and 4 weeks post-operation
Secondary outcomes (8)
Change from Baseline in Perceptual Voice Quality Total Score on the Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) Scale at 12 weeks post-operation
Perceptual rating of voice quality will be evaluated using the GRBAS scale. The scale consists of 5 components: Grade (G), Roughness (R), Breathiness (B), Asthenia (A), and Strain (S). Each component is scored from 0 (normal) to 3 (severe). The total score is calculated by summing the scores of all 5 components. Total scores range from 0 to 15, where a score of 0 represents normal voice quality and a score of 15 represents the most severe voice impairment. Higher scores indicate a worse clinical outcome.
Baseline GRBAS total score will be subtracted from the 12-week post-operative total score. A negative change score indicates an improvement in voice quality, while a positive change score indicates a worsening of voice quality.
Measured: Baseline and 12 weeks post-operation
Change from Baseline in Perceptual Voice Quality Total Score on the Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) Scale at 4 weeks post-operation
Perceptual rating of voice quality will be evaluated using the GRBAS scale. The scale consists of 5 components: Grade (G), Roughness (R), Breathiness (B), Asthenia (A), and Strain (S). Each component is scored from 0 (normal) to 3 (severe). The total score is calculated by summing the scores of all 5 components. Total scores range from 0 to 15, where a score of 0 represents normal voice quality and a score of 15 represents the most severe voice impairment. Higher scores indicate a worse clinical outcome.
Baseline GRBAS total score will be subtracted from the 4-week post-operative total score. A negative change score indicates an improvement in voice quality, while a positive change score indicates a worsening of voice quality.
Measured: Baseline and 4 weeks post-operation
Glottal Closure Type at 4 weeks post-operation
Glottal closure configuration will be assessed by videostroboscopy according to the pattern of vocal fold contact during phonation and classified as: 1 = Complete closure; 2 = Anterior Gap; 3=Posterior Gap; 4=Hourglass gap; 5 = Spindle gap; 6 = Irregular gap; 7 = Incomplete closure. A lower numerical category, particularly a transition from an open-gap configuration (categories 2-7) to complete closure (category 1), will be considered an improvement in vocal fold function.
Measured: 4 weeks post-operation
Glottal Closure Type at 12 weeks post-operation
Glottal closure configuration will be assessed by videostroboscopy according to the pattern of vocal fold contact during phonation and classified as: 1 = Complete closure; 2 = Anterior Gap; 3=Posterior Gap; 4=Hourglass gap; 5 = Spindle gap; 6 = Irregular gap; 7 = Incomplete closure. A lower numerical category, particularly a transition from an open-gap configuration (categories 2-7) to complete closure (category 1), will be considered an improvement in vocal fold function.
Measured: 12 weeks post-operation
Peri-procedural pain at Day 1
The Numeric Rating Scale (NRS 0-10) is a 11-point self-report tool used to measure peri-procedural pain intensity, where 0 represents "no pain" and 10 represents "the worst pain imaginable".
Measured: Day 1
Procedural tolerability at Day 1
Procedural tolerability using a Numeric Rating Scale (NRS) 0-10 measures how well a patient can accept and withstand the study intervention, where 0 means no pain or discomfort, the fully tolerable and 10 means the worst imaginable pain or most intolerable experience possible.
Measured: Day 1
Difficulty of performing the intervention at Day 1
The Numeric Rating Scale (NRS) is an 11-point scale (0-10) that can be adapted by a surgeon to quantify the technical difficulty or complexity of performing the study intervention. In a scale of 0 (very easy) to 10 (very difficult).
Measured: Day 1
Change from Baseline in Voice Handicap Index (VHI-30) at 12 weeks post-operation
The Voice Handicap Index (VHI-30) is a 30-item self-administered patient-reported outcome measure for voice-related disability, comprising physical, functional, and emotional subscales. In a scale of 0 (Never), 1 (Seldom), 2 (Occasionally), 3 (Frequently) and 4 (Always). Score range 0-120; higher scores indicate greater handicap. Baseline total score of Voice Handicap Index (VHI-30) will be subtracted from 12-week post-operative total score.
Measured: Baseline and 12 weeks post-operation
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Oct 2026
- Study start21 Oct 2026 (estimated)
- Primary completion30 Apr 2029 (estimated)
- Study completion30 Jun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spasmodic DysphoniaStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This is a prospective, randomized, within-patient 2×2 crossover non-inferiority trial. Each participant will serve as their own control, receiving both endoscopic-catheter method of BTX injection and EMG-guided BTX injection, in a randomized sequence across two consecutive injection cycles. The crossover design capitalizes on the natural and predictable re-injection pattern of AdSD patients and eliminates between-subject variability as a source of confounding, maximizing statistical power and minimizing required sample size.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 17 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tam Aurora Ka Yue, Chinese University of Hong Kong
- Investigators
- Aurora Ka Yue Tam, Principal investigator, Prince of Wales Hospital, Shatin, Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07894172
- Sponsor's protocol ID
- CREC 2026.322
- Status last verified
- Oct 2026
- First submitted
- 1 Oct 2026
- Last updated
- 26 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized Controlled Trial of EMG-Guided Versus Endoscopic-Catheter Botulinum Toxin Injection for Spasmodic Dysphonia
- ClinicalTrials.gov ID
- NCT07894172
- Acronym / sponsor ID
- CREC 2026.322
- Conditions
- Spasmodic Dysphonia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 17 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 21 Oct 2026 (estimated)
- Primary completion
- 30 Apr 2029 (estimated)
- Study completion
- 30 Jun 2029 (estimated)
- First posted
- 26 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This randomized, controlled non-inferiority trial will compare two established botulinum toxin injection techniques for adductor spasmodic dysphonia: percutaneous electromyography-guided injection and transnasal endoscopic catheter-guided injection. The study will evaluate whether the endoscopic technique provides voice outcomes that are not inferior to the standard EMG-guided approach, while also assessing treatment-related adverse effects, procedural tolerability, and practical advantages such as direct visualization and suitability for patients with challenging neck anatomy.
Detailed description
Spasmodic dysphonia (SD) is a rare neurological disorder caused by involuntary and intermittent spasms of intrinsic laryngeal muscles. Depending on the intrinsic muscles involved, SD is typically classified into 3 types: Adductor SD (AdSD), abductor SD (AbSD), and mixed SD. AdSD is the most common form of SD, and is a task-specific laryngeal dystonia involving the thyroarytenoid (TA) and lateral cricoarytenoid (LCA) muscles during phonation, resulting in a strained, strangled, and effortful voice with intermittent voice breaks. Symptoms typically first manifest in the mid-30s and may persist as a lifelong condition.
While there is no cure for AdSD and high rate of long term failure with surgical treatment, botulinum toxin (BTX) injection into the TA muscles has been established as the gold-standard treatment for AdSD since the 1980s, with a success rate in voice symptoms improvement up to 90%. BTX blocks acetylcholine release at the neuromuscular junction, producing reversible chemodenervation of the hyperactive intrinsic laryngeal musculature. Relief typically commences within a few days post-injection, with voice improvement lasting approximately 3-4 months before symptom recurrence, requiring repeated injections.
Several techniques have been developed over the years for the administration of BTX into the adductor compartment. The well-established percutaneous electromyography (EMG)-guided approach targets the TA/LCA complex in a transcricothyroid manner, where a needle is introduced through the cricothyroid membrane under real-time EMG feedback and allows confirmation of correct muscle placement during phonation. With the advancements of surgical endoscopes, the endoscopic-catheter injection approach has been a recently described technique also favoured by many surgeons. It is performed transnasally using flexible laryngoscopes, allowing for direct visual confirmation of needle placement into the TA/LCA muscle and false cord via a working-channel catheter.
Proposed benefits of the transnasal endoscopic-catheter approach include the ability to divide BTX injections into sub-doses targeting TA/LCA muscles and false cords, instead of injecting as a whole block as in the EMG-guided approach, potentially producing less breathiness as less total dosage is administered on any one TA muscle. Additionally, it might be particularly useful in cases with anatomical limitations, such as those with non-palpable neck landmarks or poor neck exposure with difficulty/inability in neck extension.
Despite the widespread use of both methods, no randomized controlled trial has directly compared their functional outcomes in a rigorous non-inferiority framework. Previous prospective trials have compared the EMG-guided approach to other methods such as the "point-touch" approach or the endoscopic-guided percutaneous injection approach , showing similar effectiveness amongst these techniques. However, no previous studies have compared the EMG-guided approach to the transnasal endoscopic-catheter approach. It is therefore important to establish non-inferiority of the transnasal endoscopic-catheter approach and capture the comparative advantages and limitations of the two techniques under a randomised and controlled trial setting.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- This is a prospective, randomized, within-patient 2×2 crossover non-inferiority trial. Each participant will serve as their own control, receiving both endoscopic-catheter method of BTX injection and EMG-guided BTX injection, in a randomized sequence across two consecutive injection cycles. The crossover design capitalizes on the natural and predictable re-injection pattern of AdSD patients and eliminates between-subject variability as a source of confounding, maximizing statistical power and minimizing required sample size.
| Arm | Type | Receives |
|---|---|---|
| Arm EMG | Active comparator | Procedure: Intervention A - Electromyography (EMG)-Guided BTX Injection, Procedure: Intervention B - Endoscopic Catheter BTX InjectionArm EMG: Each participant will receive Intervention A (EMG-guided injection) at Week 0; then a washout period of 14 weeks; and finally followed by Intervention B (endoscopic catheter injection) Crossover injection (opposite intervention) at Week 14. |
| Arm endoscopic catheter | Active comparator | Procedure: Intervention A - Electromyography (EMG)-Guided BTX Injection, Procedure: Intervention B - Endoscopic Catheter BTX InjectionArm endoscopic catheter : Each participant will receive Intervention B (endoscopic catheter injection) at Week 0; then a washout period of 14 weeks; and finally followed by Intervention A (EMG-guided injection) Crossover injection (opposite intervention) at Week 14. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age 18 years or older
- Known diagnosis of adductor spasmodic dysphonia (AdSD), who has previously received ≥1 course of BTX injection for AdSD with symptomatic benefit
- Able to independently provide informed consent
- Able to tolerate flexible laryngoscopy
Key exclusion criteria (7 listed)
- Age under 18 years
- Inability to provide independent informed consent
- Known hypersensitivity or allergy to botulinum toxin preparation or to local anaesthetics
- Documented neuromuscular junction disease (e.g. myasthenia gravis, Eaton-Lambert syndrome)
- Unable to tolerate flexible laryngoscopy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intervention A - Electromyography (EMG)-Guided BTX InjectionThe patient is positioned comfortably with the neck slightly extended. Surface reference and ground electrodes are applied. After application of EMLA cream (lidocaine 2.5%/prilocaine 2.5%) and disinfection of the skin, a 27-gauge needle electrode connected to an EMG machine is introduced percutaneously through the midline of the cricothyroid membrane and angled superiorly and laterally toward the TA muscle. Correct placement is confirmed by characteristic bursts of motor unit activity on phonation. Once confirmed, BTX is injected. The whole procedure including post-operative observation takes approximately 90 minutes. Vital signs and oxygen saturations are monitored throughout the procedure. | Procedure or surgery | Arm EMG, Arm endoscopic catheter |
| Intervention B - Endoscopic Catheter BTX InjectionFollowing administration of topical anesthesia with 5% lidocaine/0.5% phenylephrine (Co-phenylcaine) nasal spray and topical Xylocaine laryngeal spray via working channel, a transnasal channel flexible bronchoscope is introduced. A sterile catheter needle is introduced via the working channel of the bronchoscope, and BTX is injected directly into the TA/LCA muscle and false cord under direct visualization. The whole procedure including post-operative observation takes approximately 90 minutes. Vital signs and oxygen saturations are monitored throughout the procedure. | Procedure or surgery | Arm EMG, Arm endoscopic catheter |
Primary outcome
Change from Baseline in Voice Handicap Index (VHI-30) at 4 weeks post-operation
Time frame: Baseline and 4 weeks post-operation
The Voice Handicap Index (VHI-30) is a 30-item self-administered patient-reported outcome measure for voice-related disability, comprising physical, functional, and emotional subscales. In a scale of 0 (Never), 1 (Seldom), 2 (Occasionally), 3 (Frequently) and 4 (Always). Score range 0-120; higher scores indicate greater handicap. Baseline total score of Voice Handicap Index (VHI-30) will be subtracted from 4-week post-operative total score.
8 secondary outcomes
Change from Baseline in Perceptual Voice Quality Total Score on the Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) Scale at 12 weeks post-operation
Time frame: Baseline and 12 weeks post-operation
Change from Baseline in Perceptual Voice Quality Total Score on the Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) Scale at 4 weeks post-operation
Time frame: Baseline and 4 weeks post-operation
Glottal Closure Type at 4 weeks post-operation
Time frame: 4 weeks post-operation
Glottal Closure Type at 12 weeks post-operation
Time frame: 12 weeks post-operation
Peri-procedural pain at Day 1
Time frame: Day 1
Procedural tolerability at Day 1
Time frame: Day 1
Difficulty of performing the intervention at Day 1
Time frame: Day 1
Change from Baseline in Voice Handicap Index (VHI-30) at 12 weeks post-operation
Time frame: Baseline and 12 weeks post-operation
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Oct 2026.
- Individual participant dataSharing planned: Yes
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Aurora Ka Yue Tam principal investigator
Prince of Wales Hospital, Shatin, Hong Kong
Questions about this trial
What is this clinical trial studying?
A study testing Intervention A - Electromyography (EMG)-Guided BTX Injection and Intervention B - Endoscopic Catheter BTX Injection in people with Spasmodic Dysphonia, run by Chinese University of Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 26 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cherrie Ng (852-35051409, cherrieng@cuhk.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from Baseline in Voice Handicap Index (VHI-30) at 4 weeks post-operation (time frame: Baseline and 4 weeks post-operation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Oct 2026.