Vocal Cord Cyst
Conditions
Keywords
Vocal cord cyst, Transnasal laser surgery, Microlaryngeal surgery, Office based laser surgery, Awake laser laryngeal surgery, Trublue laser
Brief summary
This is a prospective randomised controlled trial conducted at two tertiary referral hospitals in Hong Kong to compare the clinical and functional outcomes of office-based awake transnasal laser-assisted laryngeal surgery (TNLS) under local anesthesia to traditional microlaryngeal surgery for vocal cord cyst under general anesthesia.
Detailed description
The aim of the study is to prospectively compare the functional and clinical outcomes of TNLS under local anesthesia and MLS under general anesthesia in managing vocal cord cysts. Office-based awake transnasal laser-assisted surgery (TNLS) has been gaining popularity in treating different laryngeal lesions, with the advantages of avoiding general anesthetic risks and minimizing healthcare-related costs. In addition, the general waiting time for surgeries under general anesthesia in public hospitals is getting longer due to the increasing population and limited resources. The investigators have recently conducted a novel randomized controlled trial in 2021-2022 comparing the functional and cost-effectiveness of traditional microlaryngeal surgery (MLS) under general anesthesia and TNLS for benign laryngeal lesions (vocal cord polyps, nodules, cysts, granuloma and Reinke's edema), and found that TNLS was superior to MLS in terms of length of stay, intraoperative complications, perioperative throat discomfort and hospital costs; while it was equivalent to MLS in terms of functional outcome, operative time and recurrence rate. However, since the previous study's main goal was to compare TNLS to MLS in a macroscopic perspective in terms of functional outcomes and cost-effectiveness, it had included a wide variety of benign laryngeal lesions, and different vocal cord lesions may respond differently to laser surgery. Vocal cord cyst is a fluid-filled sac inside the vocal cord, with 2 subtypes: 1) Epidermoid cyst due to epithelial inclusion 2) Mucous retention cyst due to glandular ductal obstruction. Vocal cord cysts typically do not resolve with voice therapy, and are traditionally excised with microlaryngeal surgery with microflap technique or marsupialization. In our previous RCT study, subgroup analysis did not show a significant difference of vocal cord cyst recurrence in both TNLS and MLS group. However, the investigators' cohort had a higher overall vocal cord cyst recurrence rate (13.8%) compared to historic cohort rate of 2.2-8.7% , which may be accounted by that the vocal cord cysts were ablated and marsupialized instead of removed in the TNLS group. Nevertheless, a recent case series by Gao and colleagues showed a good functional outcome of awake KTP-laser marsupialization in selected cases. A larger cohort is warranted to compare TNLS to MLS for vocal cord cyst. Therefore, the investigators would like to conduct a randomized controlled trial to compared tradition MLS surgery to TNLS, with hypothesis that TNLS would be non-inferior to traditional microlaryngeal surgery in benign laryngeal lesions, and with its additional benefits on minimization of anesthetic risks and hospital expenses, hopefully to expand its further application.
Interventions
For TNLS, patients are admitted to the day center on the same morning or afternoon of the surgery with fasting prior 6 hours. After local anesthesia application, a 445nm blue laser is introduced via a working channel of bronchoscope and laser ablation of vocal cord cyst is performed. During the operation, patient will receive continuous SpO2 monitoring with regular blood pressure monitoring. After the procedure, patients are kept nil-by-mouth for 2 hours until anesthesia wears off, meanwhile with close observation in day ward with continuous SpO2 monitor for 1 hour. Patients will be discharged on the same day of the procedure, with voice rest for 3 days.
PROCEDUREMicrolaryngeal surgery (MLS)
For traditional MLS under general anesthesia, after general anesthesia and intubation with microlaryngeal tube, the patient would be positioned on head-ring support for better alignment and access to glottis. A laryngoscope will be inserted transorally under direct vision and suspended. Vocal cord cysts are visualized with microscope, and removed with microsurgery instruments with microflap technique and sent for routine section. After the surgery, the patient is kept nil-by-mouth until fully awake, and is discharged on same day or the next day depending on the post- operative recovery. Patient will be discharged with voice rest for 3 days.
Sponsors
Chinese University of Hong Kong
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients with vocal cord cysts * older than 18-year-old * able to independently provide consent * able to tolerate flexible laryngoscopy would be recruited
Exclusion criteria
* under 18-year-old * unable to independently give an informed consent * unable to tolerate flexible laryngoscopy * allergic to local anesthesia * had unfavorable anatomy such as prolapsing epiglottis precluding adequate visualization, extensive lesions and an expected difficult operation as judged by the surgeons * with pathologies other than vocal cord cyst
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Voice-Handicap Index (VHI-30) | From enrolment to post-operative 1year | The primary outcome was to compare the pre- and post-operative Voice-Handicap Index 30 (VHI-30) of TNLS and MLS groups. The VHI-30 is a 30-item self-administered questionnaire, with score range from 0 to 120, and a score of 120 meaning worst voice score. It has been shown to be a reliable measure for voice treatment outcome. It consists of three subscales, namely physical, functional and emotional. It provides an overall measurement of a person's vocal function and how it influences a person's everyday functioning and experience. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Acoustic voice analysis - Noise-to-Harmonic ratio (NHR) | From enrolment to post-operative 1year | Acoustic voice analysis will be performed using PRATT program; Noise-to-Harmonic ratio refers to the ratio between periodic and non-periodic components of a speech sound. A lower NHR score may indicate a worse voice outcome. |
| Acoustic voice analysis - Jitter | From enrolment to post-operative 1year | Acoustic voice analysis will be performed using PRATT program; Jitter refers to variation of voice frequency. |
| Acoustic voice analysis - Shimmer | From enrolment to post-operative 1year | Acoustic voice analysis will be performed using PRATT program; Shimmer refers to variation of intensity of the voice. |
| Aerodynamic measure of voice | From enrolment to post-operative 1year | Aerodynamic measure, maximal phonation time (MPT) would be measured by instructing patients to phonate /a:/ sound for as long as possible after maximal inspiration, at a spontaneous, comfortable pitch and loudness level, for three consequent trials. |
| Visual analog scale (VAS) | From enrolment to post-operative 1year | In VAS, patients would be asked to self-rate their voice quality on a visual analog scale of 0 (best) to 10 (worst). |
| Videostroboscopy - Mucosal wave pattern | From enrolment to post-operative 1year | Videostroboscopy would be conducted on all patients to look for any impaired mucosal wave form. |
| Videostroboscopy - Vocal fold closure | From enrolment to post-operative 1year | Videostroboscopy would be conducted on all patients to compare the degree of vocal fold closure. |
| Perceptual evaluation of voice | From enrolment to post-operative 1year | Perceptual evaluation of voice using the GBRAS scale, in which patients would be required to produce sustained vowel and connected speech voice samples. Score range from 0 to 15, with 15 being the worst score. Two experienced speech-language pathologists blinded to the patient's information would rate the audio recordings. |
| Procedure-oriented outcomes - Disease recurrence | From perioperative period to post-operative 1 year | Comparison of the rate of vocal cord cyst recurrence between two groups. |
| Procedure-oriented outcomes - Length of hospital stay | From perioperative period to post-operative 1 year | Comparison of the length of hospital stay (number of day) between two groups. |
| Procedure-oriented outcomes - Surgical complications in Clavien-Dindo classification | From perioperative period to post-operative 1 year | Clavien-Dindo classification is a commonly used surgical complication grading system, from grade I-V with grade V indicating worst outcome (death). |
| Procedure-oriented outcomes - Completeness of lesion removal | From perioperative period to post-operative 1 year | Indicates if the vocal fold pathology has been completely removed |
| Procedure-oriented outcomes - Operation time | From perioperative period to post-operative 1 year | Comparison of the operation time between two groups in terms of minute. |
| Patient-oriented outcomes | Perioperative period | Patient-oriented outcomes included peri-operative throat, nose, and overall discomfort in visual analogue scale, a 10-point scale with 0 (least uncomfortable) to 10 (most uncomfortable). |
| Medical costs | From enrolment to post-operative 1year | Medical costs of both interventions would be also calculated respectively, including costs for inpatient hospital stay, medical staff, operating theater and consumable. |
| Procedure-oriented outcomes - Reoperation | From perioperative period to post-operative 1 year | Comparison of the rate of reoperation for recurrence vocal cord cyst between two groups. |
Countries
Hong Kong
Contacts
Primary ContactAurora KY Tam, MBBS, MRCSEd
Backup ContactWing Kei Ng
Outcome results
None listed