Patients Undergoing Open Thyroid SurgeryHuaxi TunnelNCT07298616
Hydrodissection Tunneling Technique on Recurrent Laryngeal Nerve Protection During Thyroidectomy
A study testing Hydrodissection tunneling technique in people with Patients Undergoing Open Thyroid Surgery, run by West China Hospital at 1 site in China.
Trial summary
Protection of the recurrent laryngeal nerve (RLN) is a key focus and difficulty in thyroid surgery. Unilateral RLN injury can lead to ipsilateral vocal cord paralysis, resulting in hoarseness in patients postoperatively. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Patients Undergoing Open Thyroid Surgery
- What is being tested?
- Hydrodissection tunneling technique
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 238 participants
- Where
- 1 siteChina
- Study dates
- 1 Mar 2025to 1 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged 18-75 years, regardless of gender；
- Patients hospitalized for open thyroid surgery (undergoing at least unilateral lobe and isthmus resection) and undergoing the procedure for the first time；
- Preoperative color Doppler or contrast-enhanced ultrasound assessment indicates no significant invasion of the recurrent laryngeal nerve by the lesion；
- Participants voluntarily agree to join the trial and provide signed informed consent.
Who cannot join
- History of thyroid nodule ablation therapy;
- Patients scheduled for lateral neck dissection;
- History of hypertension, atrial fibrillation, or severe arrhythmia;
- Uncontrolled subacute thyroiditis or hyperthyroidism;
- Severe comorbidities affecting major organs (cardiac, pulmonary, hepatic, or renal);
- Presence of cancer-related cachexia syndrome;
Show all 10Show fewer
- History of psychiatric disorders or cognitive impairment;
- Pregnant or lactating women;
- Participation in other clinical trials within 90 days;
- Other conditions deemed by investigators as unsuitable for trial participation
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Hydrodissection Tunneling Technique on Recurrent Laryngeal Nerve Protection During Thyroidectomy: A Multicenter, Randomized Clinical Trial
Protection of the recurrent laryngeal nerve (RLN) is a key focus and difficulty in thyroid surgery. Unilateral RLN injury can lead to ipsilateral vocal cord paralysis, resulting in hoarseness in patients postoperatively. Bilateral RLN injury, however, may cause bilateral vocal cord paralysis, leading to dyspnea and even asphyxiation; in severe cases, tracheotomy and permanent tracheal cannulation are required. Consequently, RLN injury significantly impacts patients' postoperative quality of life and career development. Guidelines and consensuses both domestically and internationally recommend that during the management of the posterior thyroid capsule, active detection, exposure, and dissection of the RLN, combined with meticulous capsular dissection along the RLN, should be performed to effectively reduce the incidence of RLN injury. While active anatomical identification of the RLN can clarify the nerve branches and their relationship with surrounding tissues, facilitating surgical procedures such as ligation and hemostasis, the traditional method of dissecting with instruments like hemostats or right-angle forceps (either blunt or sharp dissection along the nerve surface) increases the risk of nerve injury due to traction, clamping, or thermal damage. This is particularly challenging for less experienced surgeons, who face great difficulties in using energy devices near the RLN without causing injury-a major concern in the field of thyroid surgery.
Diluted epinephrine solution exhibits excellent hemostatic effects in local surgery, improves surgical field clarity, and shortens operation time. Its safety has been clinically verified, and it is commonly used in plastic and cosmetic surgery, joint surgery, and the cavity creation process of endoscopic thyroid surgery. Based on this, this study innovatively proposes the "Huaxi Tunnel Technique": on the basis of meticulous posterior capsular dissection in traditional thyroid surgery, the RLN detection point on the posterior capsule below the lower pole of the thyroid is located using the "cross method" and exposed. A syringe containing diluted epinephrine solution is then used, with its front hose inserted along the RLN towards the laryngeal entry direction. Rapid injection is performed, and the pressure generated by this injection separates the fibrous connective tissue on the RLN surface, forming a "tunnel" from the RLN detection point to the laryngeal entry site-thus achieving exposure and dissection of the RLN.
This technique offers multiple advantages: epinephrine reduces local bleeding, enhancing surgical safety and the convenience of meticulous capsular dissection; tunnel formation causes edema and discoloration of the fibrous connective tissue in the posterior thyroid capsule (while the parathyroid glands remain uncolored), facilitating the rapid identification and protection of the parathyroid glands. Preliminary preclinical experiments have confirmed that the technique reduces the difficulty of RLN exposure and dissection, decreases intraoperative bleeding and complication rates, and improves the safety of thyroid surgery. To further evaluate the efficacy, safety, and operability of this tunnel technique for RLN exposure and dissection, a prospective single-blind randomized controlled trial comparing it with traditional thyroid surgery methods is hereby conducted.
Read the detailed description
This study is a multicenter, single-blind, randomized controlled trial. Eligible patients will be randomly assigned in a 1:1 ratio to either the experimental group (hydrodissection tunneling technique) or the control group (conventional dissection technique).
- Conditions
- Patients Undergoing Open Thyroid Surgery
- Being tested
- Hydrodissection tunneling technique
- Keywords
- thyroid surgery, recurrent laryngeal nerve, Huaxi tunnel technique, epinephrine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hydrodissection tunneling techniqueProcedure or surgery
Also called adrenaline
A 5-ml syringe was loaded with adrenaline solution diluted in normal saline (1 mg adrenaline in 250 ml saline, concentration 4 µg/ml) and fitted with a 2-3 cm soft extension tube as the injection tip. After the recurrent laryngeal nerve (RLN) was identified by the cross-hatch method at the posteroinferior capsule below the lower pole of the thyroid gland, the solution was rapidly injected along the RLN's course toward its laryngeal entry point. The hydraulic pressure created by this rapid injection separated the fibrous connective tissue surrounding the nerve, forming a tissue tunnel from the initial identification site to the laryngeal entry point. Subsequent nerve dissection was then performed within this tunnel.
| Study group | Role | What they receive |
|---|---|---|
| Hydrodissection tunneling technique | Experimental | Experimental group (Hydrodissection tunneling technique):
A 5-ml syringe was loaded with adrenaline solution diluted in normal saline (1 mg adrenaline in 250 ml saline, concentration 4 µg/ml) and fitted with a 2-3 cm soft extension tube as the injection tip. After the recurrent laryngeal nerve (RLN) was identified by the cross-hatch method at the posteroinferior capsule below the lower pole of the thyroid gland, the solution was rapidly injected along the RLN's course toward its laryngeal entry point. The hydraulic pressure created by this rapid injection separated the fibrous connective tissue surrounding the nerve, forming a tissue tunnel from the initial identification site to the laryngeal entry point. Subsequent nerve dissection was then performed within this tunnel. Receives: Procedure: Hydrodissection tunneling technique |
| Control group | No intervention | Control group (conventional group): the group in which the recurrent laryngeal nerve was exposed and the thyroid gland was resected by standard thyroid surgical techniques. |
What is being measured
The primary outcome is the main question the study is designed to answer.
The incidence of significant amplitude reduction (SAR) events of RLN
SAR was defined as a 50% or greater decrease in electromyographic amplitude from the initial baseline at 1.0-mA or 3.0-mA stimulation.
Measured: Intraoperative
Secondary outcomes (9)
Total operative time
The interval from skin incision to skin closure is recorded to evaluate the impact of the different surgical techniques on overall procedure length.
Measured: Intraoperative
V-RQOL questionnaire
Voice-Related Quality of Life-10 (V-RQOL-10): Comprising 10 items, it includes two dimensions: social-emotional and physical-functional. The content of the items describes the subjective experiences of patients with voice disorders. Severity is rated on a scale of 1 to 5, where 1 represents "not at all," 2 represents "a little," 3 represents "a moderate amount," 4 represents "a lot," and 5 represents "extremely." This questionnaire uses "reverse scoring" and must ultimately be converted to a range of 0 to 100 points. A higher overall score indicates better voice quality, while a lower score indicates poorer voice quality.Patients need to complete the V-RQOL questionnaire before surgery and on the first day after surgery.
Measured: The day before surgery, 1 day postoperative
VHI-10
A voice disorder index scale consisting of 10 items, including 5 functional items, 3 physical items, and 2 emotional items. Each item is scored from 0 to 4, with different scores representing the frequency of occurrence: "never" = 0; "rarely" = 1; "sometimes" = 2; "often" = 3; and "always" = 4. A higher score indicates a greater impact of voice disorders on that aspect and a more severe self-assessment of voice impairment. The critical value for VHI is 8 points, and individuals with a VHI score ≥ 8 are considered to have voice dysfunction. Patients need to complete the VHI-10 questionnaire before surgery and on the first day after surgery.
Measured: The day before surgery, 1 day postoperative
Assessment of parathyroid gland identification and preservation
The evaluation is carried out in four domains: (1)Vascularity of the preserved parathyroid glands;(2) Surgeon's subjective rating of parathyroid recognizability during operation (poor / fair / good);(3) Intra-operative autotransplantation of parathyroid tissue (number of fragments transplanted);(4)Change in serum PTH and calcium levels from pre-operative to post-operative measurements
Measured: Preoperative, Intraoperative, 1 day postoperative, 1 month postoperative
Recurrent laryngeal nerve injury signal amplitude
Differences in nerve signal amplitude before and after RLN dissection at 1 mA and 3 mA.
Measured: Intraoperative
Postoperative drainage volume
The total drain output before removal is recorded to assess the impact of the different surgical techniques on overall postoperative drainage.
Measured: 1 day postoperative, 2 days postoperative, 3 days postoperative, 4 days postoperative
Duration of RLN dissection
The time point immediately before and immediately after nerve dissection are recorded, and the interval is calculated as the time required for RLN dissection.
Measured: Intraoperative
Assessment of bleeding during RLN dissection
After the nerve is identified, a dry gauze is placed; the difference in gauze weight before and after nerve dissection is used to quantify blood loss.
Measured: Intraoperative
Assessment of local epinephrine-related adverse effects
Pre-operative and first post-operative day heart rate is recorded, together with the highest intra-operative HR values, to evaluate side-effects of topical epinephrine use.
Baseline data including history of arrhythmia is also registered.
Measured: The day before surgery, Intraoperative, 1 day postoperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Dec 2025
- Study start1 Mar 2025
- Primary completion1 Jan 2026
- Study completion1 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Patients Undergoing Open Thyroid SurgeryStudies of the same condition, open and under way.
- More trials run by West China HospitalThe 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
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 238 participants (actual)
Sponsor and investigators
- Lead sponsor
- West China Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- West China Tianfu Hospital, Shang Jin Hospital of West China Hospital,Sichuan University, Sun Yat-Sen University Cancer Center, Sichuan Provincial People's Hospital, Sanya People's Hospital
- Responsible party
- Principal investigator, Yu Feng, West China Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07298616
- Sponsor's protocol ID
- 2024（2498）
- Acronym
- Huaxi Tunnel
- Status last verified
- Aug 2026
- First submitted
- 22 Nov 2025
- Last updated
- 19 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
GBD 2019 Diseases and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020 Oct 17;396(10258):1204-1222. doi: 10.1016/S0140-6736(20)30925-9.
PubMed 33069326Haymart MR. Progress and Challenges in Thyroid Cancer Management. Endocr Pract. 2021 Dec;27(12):1260-1263. doi: 10.1016/j.eprac.2021.09.006. Epub 2021 Sep 22.
PubMed 34562612
Study at a glance
From the registry record, last updated by the sponsor on 19 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Hydrodissection Tunneling Technique on Recurrent Laryngeal Nerve Protection During Thyroidectomy: A Multicenter, Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07298616
- Acronym / sponsor ID
- Huaxi Tunnel / 2024（2498）
- Conditions
- Patients Undergoing Open Thyroid Surgery
- Keywords
- thyroid surgery, recurrent laryngeal nerve, Huaxi tunnel technique, epinephrine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 238 participants (actual)
- Lead sponsor
- West China HospitalUniversity, hospital or other
- Collaborators
- West China Tianfu Hospital, Shang Jin Hospital of West China Hospital,Sichuan University, Sun Yat-Sen University Cancer Center, Sichuan Provincial People's Hospital, Sanya People's Hospital
- Study start
- 1 Mar 2025 (actual)
- Primary completion
- 1 Jan 2026 (actual)
- Study completion
- 1 Mar 2026 (actual)
- First posted
- 23 Dec 2025 (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.
Protection of the recurrent laryngeal nerve (RLN) is a key focus and difficulty in thyroid surgery. Unilateral RLN injury can lead to ipsilateral vocal cord paralysis, resulting in hoarseness in patients postoperatively. Bilateral RLN injury, however, may cause bilateral vocal cord paralysis, leading to dyspnea and even asphyxiation; in severe cases, tracheotomy and permanent tracheal cannulation are required. Consequently, RLN injury significantly impacts patients' postoperative quality of life and career development. Guidelines and consensuses both domestically and internationally recommend that during the management of the posterior thyroid capsule, active detection, exposure, and dissection of the RLN, combined with meticulous capsular dissection along the RLN, should be performed to effectively reduce the incidence of RLN injury. While active anatomical identification of the RLN can clarify the nerve branches and their relationship with surrounding tissues, facilitating surgical procedures such as ligation and hemostasis, the traditional method of dissecting with instruments like hemostats or right-angle forceps (either blunt or sharp dissection along the nerve surface) increases the risk of nerve injury due to traction, clamping, or thermal damage. This is particularly challenging for less experienced surgeons, who face great difficulties in using energy devices near the RLN without causing injury-a major concern in the field of thyroid surgery.
Diluted epinephrine solution exhibits excellent hemostatic effects in local surgery, improves surgical field clarity, and shortens operation time. Its safety has been clinically verified, and it is commonly used in plastic and cosmetic surgery, joint surgery, and the cavity creation process of endoscopic thyroid surgery. Based on this, this study innovatively proposes the "Huaxi Tunnel Technique": on the basis of meticulous posterior capsular dissection in traditional thyroid surgery, the RLN detection point on the posterior capsule below the lower pole of the thyroid is located using the "cross method" and exposed. A syringe containing diluted epinephrine solution is then used, with its front hose inserted along the RLN towards the laryngeal entry direction. Rapid injection is performed, and the pressure generated by this injection separates the fibrous connective tissue on the RLN surface, forming a "tunnel" from the RLN detection point to the laryngeal entry site-thus achieving exposure and dissection of the RLN.
This technique offers multiple advantages: epinephrine reduces local bleeding, enhancing surgical safety and the convenience of meticulous capsular dissection; tunnel formation causes edema and discoloration of the fibrous connective tissue in the posterior thyroid capsule (while the parathyroid glands remain uncolored), facilitating the rapid identification and protection of the parathyroid glands. Preliminary preclinical experiments have confirmed that the technique reduces the difficulty of RLN exposure and dissection, decreases intraoperative bleeding and complication rates, and improves the safety of thyroid surgery. To further evaluate the efficacy, safety, and operability of this tunnel technique for RLN exposure and dissection, a prospective single-blind randomized controlled trial comparing it with traditional thyroid surgery methods is hereby conducted.
Detailed description
This study is a multicenter, single-blind, randomized controlled trial. Eligible patients will be randomly assigned in a 1:1 ratio to either the experimental group (hydrodissection tunneling technique) or the control group (conventional dissection technique).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Hydrodissection tunneling technique | Experimental | Procedure: Hydrodissection tunneling techniqueExperimental group (Hydrodissection tunneling technique): A 5-ml syringe was loaded with adrenaline solution diluted in normal saline (1 mg adrenaline in 250 ml saline, concentration 4 µg/ml) and fitted with a 2-3 cm soft extension tube as the injection tip. After the recurrent laryngeal nerve (RLN) was identified by the cross-hatch method at the posteroinferior capsule below the lower pole of the thyroid gland, the solution was rapidly injected along the RLN's course toward its laryngeal entry point. The hydraulic pressure created by this rapid injection separated the fibrous connective tissue surrounding the nerve, forming a tissue tunnel from the initial identification site to the laryngeal entry point. Subsequent nerve dissection was then performed within this tunnel. |
| Control group | No intervention | –Control group (conventional group): the group in which the recurrent laryngeal nerve was exposed and the thyroid gland was resected by standard thyroid surgical techniques. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Aged 18-75 years, regardless of gender；
- Patients hospitalized for open thyroid surgery (undergoing at least unilateral lobe and isthmus resection) and undergoing the procedure for the first time；
- Preoperative color Doppler or contrast-enhanced ultrasound assessment indicates no significant invasion of the recurrent laryngeal nerve by the lesion；
- Participants voluntarily agree to join the trial and provide signed informed consent.
Key exclusion criteria (10 listed)
- History of thyroid nodule ablation therapy;
- Patients scheduled for lateral neck dissection;
- History of hypertension, atrial fibrillation, or severe arrhythmia;
- Uncontrolled subacute thyroiditis or hyperthyroidism;
- Severe comorbidities affecting major organs (cardiac, pulmonary, hepatic, or renal);
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 |
|---|---|---|
| Hydrodissection tunneling techniqueAlso: adrenalineA 5-ml syringe was loaded with adrenaline solution diluted in normal saline (1 mg adrenaline in 250 ml saline, concentration 4 µg/ml) and fitted with a 2-3 cm soft extension tube as the injection tip. After the recurrent laryngeal nerve (RLN) was identified by the cross-hatch method at the posteroinferior capsule below the lower pole of the thyroid gland, the solution was rapidly injected along the RLN's course toward its laryngeal entry point. The hydraulic pressure created by this rapid injection separated the fibrous connective tissue surrounding the nerve, forming a tissue tunnel from the initial identification site to the laryngeal entry point. Subsequent nerve dissection was then performed within this tunnel. | Procedure or surgery | Hydrodissection tunneling technique |
Primary outcome
The incidence of significant amplitude reduction (SAR) events of RLN
Time frame: Intraoperative
SAR was defined as a 50% or greater decrease in electromyographic amplitude from the initial baseline at 1.0-mA or 3.0-mA stimulation.
9 secondary outcomes
Total operative time
Time frame: Intraoperative
V-RQOL questionnaire
Time frame: The day before surgery, 1 day postoperative
VHI-10
Time frame: The day before surgery, 1 day postoperative
Assessment of parathyroid gland identification and preservation
Time frame: Preoperative, Intraoperative, 1 day postoperative, 1 month postoperative
Recurrent laryngeal nerve injury signal amplitude
Time frame: Intraoperative
Postoperative drainage volume
Time frame: 1 day postoperative, 2 days postoperative, 3 days postoperative, 4 days postoperative
Duration of RLN dissection
Time frame: Intraoperative
Assessment of bleeding during RLN dissection
Time frame: Intraoperative
Assessment of local epinephrine-related adverse effects
Time frame: The day before surgery, Intraoperative, 1 day postoperative
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Aug 2026.
- Results publication: PubMed 33069326GBD 2019 Diseases and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020 Oct 17;396(10258):1204-1222. doi: 10.1016/S0140-6736(20)30925-9.
- Results publication: PubMed 34562612Haymart MR. Progress and Challenges in Thyroid Cancer Management. Endocr Pract. 2021 Dec;27(12):1260-1263. doi: 10.1016/j.eprac.2021.09.006. Epub 2021 Sep 22.
- Individual participant dataSharing planned: Undecided
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hydrodissection tunneling technique in people with Patients Undergoing Open Thyroid Surgery, run by West China Hospital at 1 site in China.
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 10 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: finished, as of the sponsor's last update on 19 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The incidence of significant amplitude reduction (SAR) events of RLN (time frame: Intraoperative). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07298616, which also lists 2 linked publications.
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 19 Aug 2026.