Training for Awake, Office-Based Laryngeal Procedures-The Laryngology Fellow's Perspective

OBJECTIVE

The aim was to explore recent laryngology graduates' perspectives on their experience, competency, and challenges learning office-based procedures during fellowship training in the United States and Canada.

METHODS

Anonymous 22-item questionnaire survey was distributed electronically to fellowship-trained laryngologists having completed fellowship within past 5 years.

RESULTS

Ninety fellowship-trained laryngologists between 2018 and 2022 were surveyed. Response rate was 48.9% (n = 44), 1 declined participation, with 20 different fellowship programs represented. Fellows were frequently provided the opportunity to act as primary surgeon for most procedures, except for laryngeal botulinum toxin injection, diagnostic laryngeal electromyography, trans-nasal esophagoscopy, secondary tracheoesophageal puncture, and high-resolution pharyngeal manometry. A majority reported high (n = 27, 62.8%) or moderate (n = 12, 27.9%) confidence with vocal fold injection augmentation. Various techniques were taught: transoral (74.4%), cricothyroid (74.4%), thyrohyoid (69.8%), transcartilagenous (14.0%), and catheter-needle (25.6%). Numerous statistically significant associations with independent procedure involvement and competence were identified. Laryngeal botulinum toxin injection was a procedure performed with high frequency but low volume of independent fellow involvement, and the procedure with which fellows reported wanting more practice learning. Most common training barriers included patient being awake, patient consenting to trainee performing the procedure, and the technical challenge/complexity of the procedure. Teaching methods/tools largely focused on informal debriefing (97.3%) and case by case troubleshooting (81.1%).

CONCLUSIONS

Laryngology fellows are well trained with favorable perceived levels of competence for numerous office-based procedures, particularly vocal fold injection augmentation. Procedures for which fellows reported a low level of independent participation trended towards lower perceived competency.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:873-881, 2024.

Prospective >12 Months Outcomes After Vocal Fold Injection Medialization With Silk Microparticle-Hyaluronic Acid Material

OBJECTIVE

Vocal fold injection medialization (VFIM) is widely used as an initial treatment for unilateral vocal fold paralysis (UVFP). Current practices employ materials that share the limitation of temporary clinical effect from variable resorption rates. A novel silk protein microparticle-hyaluronic acid-based material (silk-HA) has demonstrated cellular infiltration and tissue deposition that may portend a durable medialization effect. We report on ≥12 months outcomes after VFIM with silk-HA.

METHODS

Prospective open-label study of patients with UVFP that elected treatment with VFIM with silk-HA. Blinded experts rated laryngeal stroboscopic exams.

RESULTS

Seventeen patients with UVFP underwent VFIM with silk-HA. Twelve of the 17 patients have ≥12 months follow-up. Seven patients demonstrated durable treatment benefit ≥12 months after injection with median improvement of 19 (p = 0.0156) in VHI-10. There was no significant change in VHI-10 between 1 and 12 months for these patients. Blinded ratings indicated that 5/7 patients with sustained improvements in VHI-10 exhibited complete or touch glottal closure at 12 months. Two of the seven patients exhibited a small (<1 mm) glottal gap at 12 months. Seven patients experienced initial benefit with later regression 3-4 months after injection.

CONCLUSION

VFIM with silk-HA can offer durable improvement in voice-related outcomes for UVFP past 12 months. A subset of patients treated with silk-HA experienced early loss of effect around 3-4 months postinjection. Clinical factors predictive of sustained treatment response to silk-HA injection require further exploration.

LEVEL OF EVIDENCE

3 Laryngoscope, 2023.

Use of Botulinum Toxin in Spasmodic Dysphonia: A Review of Recent Studies

Spasmodic dysphonia (SD), also known as laryngeal dystonia, is a neurological voice disorder that causes involuntary spasms of the vocal cord muscles. This impacts speech to varying degrees and results in strained and strangled voice quality, as in adductor spasmodic dysphonia, or weak, quiet, and breathy, as in abductor spasmodic dysphonia. While there is currently no cure for SD, voice therapy and chemodenervation with botulinum toxin (btx) injections remain the mainstay of management. Surgery may be performed in some cases; however, btx injections are widely used to treat both adductor and abductor forms of SD. While btx injections may show vocal improvement in both types of SD, results can depend on several factors such as the general health of the patient, onset and severity of the condition, dosage, interval between injections, and expertise of the practitioner. While many studies have documented the efficacy of btx for improving vocal symptoms in individuals with SD, this review aims to discuss some of those studies from the last 10 years.

Tissue Engineering as a Promising Treatment for Glottic Insufficiency: A Review on Biomolecules and Cell-Laden Hydrogel

Glottic insufficiency is widespread in the elderly population and occurs as a result of secondary damage or systemic disease. Tissue engineering is a viable treatment for glottic insufficiency since it aims to restore damaged nerve tissue and revitalize aging muscle. After injection into the biological system, injectable biomaterial delivers cost- and time-effectiveness while acting as a protective shield for cells and biomolecules. This article focuses on injectable biomaterials that transport cells and biomolecules in regenerated tissue, particularly adipose, muscle, and nerve tissue. We propose Wharton's Jelly mesenchymal stem cells (WJMSCs), induced pluripotent stem cells (IP-SCs), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), insulin growth factor-1 (IGF-1) and extracellular vesicle (EV) as potential cells and macromolecules to be included into biomaterials, with some particular testing to support them as a promising translational medicine for vocal fold regeneration.

Prolonged persistence of hyaluronic acid after suboptimal vocal fold injection

Hyaluronic acid (HA) is a commonly used injectable material in temporary vocal fold injections (VFI) in patients with unilateral vocal fold paralysis (UVFP). Hyaluronic acid has generally been known for its three-six months of longevity following VFI. Owing to recent advances in cross-linking technologies, the longevity of HA-based materials, including deep-volumizing cross-linked HA used in VFI, has been improved. However, persisting injectable material in the subepithelial space poses undesirable complications following VFI. Herein, we report 2 cases of unexpected persistence of superficially injected cross-linked HA. In the first case, a 70-year-old man with iatrogenic UVFP received VFI with cross-linked HA three years ago and was referred for persistent dysphonia. Previously injected HA spilled out from the vocal fold (VF) when an epithelial incision was made in the subepithelial cystic lesion. In the second case, a 72-year-old woman with iatrogenic UVFP received VFI with cross-linked HA that migrated into the subepithelial space. Diffuse swelling of the injected VF caused dysphonia that lasted for a year. The previously injected HA spilled out when an epithelial incision was made in the swollen VF. Since superficially injected deep-volumizing cross-linked HA can persist for up to three years, laryngologists should be aware of possible sequelae upon suboptimal VFI with cross-linked HA.

Autologous Adipose Tissue Injection of Vocal Cords in Presbyphonia

OBJECTIVE

This series evaluates the long-term results of autologous adipose injection (AAI) in patients older than 65 years with presbyphonia.

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic secondary medical center.

METHODS

This was a retrospective study with a minimum follow-up of 12 months. All patients underwent AAI for atrophy of both vocal folds due to presbyphonia. We measured subjective parameters as Voice Handicap Index-10 (VHI-10) or GRBAS scale (grade, roughness, breathiness, asthenia, strain) and objective measures such as maximum phonation time (MPT) or square pixel closure defect. We reviewed the medical records of patients undergoing AAI during the 2011-2018 period. An analysis of the demographic variables of the group was performed, as well as the values of VHI-10, GRBAS, and MPT, and the minimum closure defect measured in square pixels and the number of closed frames in the glottal cycle before and after the intervention.

RESULTS

At 12 months, 17 of 18 patients reported subjective and VHI-10 improvement. The mean preoperative VHI-10 (26.7) was significantly higher than the postoperative value (14.4), and the GRBAS scale had a preoperative mean of 8.7 and a postoperative mean of 4.3, both with statistical significance. MPT increased from 7.7 to 12.4 seconds (P < .0001). The minimum closure defect measurements obtained in square pixels changed from 305 to 124, achieving complete closure in 3 patients. The closed phase of the glottal cycle change from 14.3% to 38.2% after the AAI.

CONCLUSIONS

AAI improves long-term vocal fold closure, demonstrating utility in patients with presbyphonia.

Dysphagia Severity and Outcomes Following Iatrogenic High Vagal Nerve Injury

OBJECTIVE

To examine severity of dysphagia and outcomes following iatrogenic high vagal nerve injury.

METHODS

Retrospective chart review of all patients with iatrogenic high vagal nerve injury that were seen at a tertiary referral center from 2012 to 2020.

RESULTS

Of 1304 patients who met criteria for initial screening, 18 met all inclusion criteria. All 18 required intervention to address postoperative dysphagia. Eleven required enteral feeding tubes with 7 eventually able to advance to exclusively per oral diets. Fourteen underwent vocal fold injection and 6 underwent laryngeal framework surgery. Sixteen pursued swallowing therapy with speech language pathology. Patients lost a mean of 8.6 kg of weight in the 6 months following the injury. Swallowing function on the Functional Outcome Swallowing Scale (FOSS) and Functional Oral Intake Scale (FOIS) was 4.4 and 2.4 respectively immediately following the injury and improved to 1.9 and 5.3 at the last follow-up. No patients had complete return of normal swallowing function at last follow up.

CONCLUSION

Iatrogenic high vagal injury causes significant lasting dysphagia which improves with intervention but does not completely resolve. Interventions such as vocal fold injection, medialization laryngoplasty, cricopharyngeal myotomy, or swallowing therapy may be required to reestablish safe swallowing in these patients.

Vocal fold injection material does not preclude interpretation of laryngeal electromyography

INTRODUCTION/AIMS

Temporary vocal fold injection (VFI) is a common treatment for acute and subacute vocal fold paralysis (VFP). Laryngeal electromyography (LEMG) is useful for diagnosing neurogenic causes of VFP. This study evaluated whether the presence of VFI material prevents interpretation of LEMG in patients with acute and subacute VFP.

METHODS

Patients with acute and subacute unilateral VFP (onset ≤6 mo) who underwent temporary VFI within 3 mo preceding LEMG were evaluated. A matched control group that did not undergo VFI was also studied. The LEMG team (laryngologist and electromyographer) performed and interpreted LEMG using a pre-specified protocol, including qualitative and quantitative motor unit analysis.

RESULTS

Eighteen patients with VFI underwent LEMG successfully with interpretation of spontaneous activity and motor unit recruitment. Fourteen patients were seen in follow-up to determine accuracy of established LEMG prognosis. Seven of seven subjects with poor LEMG prognosis did not recover vocal fold motion. Five of seven subjects with fair LEMG prognosis recovered vocal fold motion. Findings were similar for the control group.

DISCUSSION

VFI augmentation material did not prevent interpretation of meaningful LEMG data in patients with acute and subacute VFP, and accurate prognoses of vocal fold motion recovery were established.

Vocal Fold Injection Augmentation for Post-Airway Reconstruction Dysphonia: A Case Series

OBJECTIVES

Post airway reconstruction dysphonia (PARD) is common and has a significant effect on the quality of life of patients. Vocal fold injection augmentation (VFIA) is one treatment that can be used to improve glottic insufficiency in some patients. The goal of this study was to characterize the use and outcomes of VFIA for PARD.

METHODS

Retrospective chart review from January 2007 to July 2018 at a tertiary pediatric care center. Consecutive patients with PARD who underwent VFIA, who had a preoperative voice evaluation and a follow-up evaluation within 3 months after VFIA (fat, carboxymethylcellulose gel, hyaluronic acid).

RESULTS

Thirty-four patients (20 female) underwent VFIA. The mean age at the time of the injection was 13.6 years (SD 6.1). Twenty patients (58.8%) had a history of prematurity and a mean of 1.8 open airway surgeries. After injection, 29/34 patients (85.3%) noted a subjective voice improvement. The baseline Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) overall severity score decreased by a mean of 5.7 (SD = 19.6) points, P = .12. Total pediatric Voice Handicap Index (pVHI) improved by 6.0 (SD = 19.5) points, from 57.4 (SD = 20.0) to 51.4 (SD = 17.2), P = .09. Functional pVHI subscore demonstrated a significant improvement, with a decrease of 3.4 (SD = 7.3) points, P = .02. All procedures were performed as an overnight observation and no complication occurred.

CONCLUSION

Patients with PARD represent a complex subset of patients. VFIA is a straightforward intervention that may improve voice perception. Many patients reported subjective improvement despite minimal objective measurement. Further work is warranted to elucidate the role of injection in management of PARD.

Effect of Vocal Fold Implant Placement on Depth of Vibration and Vocal Output

OBJECTIVE

Most type 1 thyroplasty implants and some common injectable materials are mechanically stiff. Placing them close to the supple vocal fold mucosa can potentially dampen vibration and adversely impact phonation, yet this effect has not been systematically investigated. This study aims to examine the effect of implant depth on vocal fold vibration and vocal output.

STUDY DESIGN

Computational simulation.

METHODS

Voice production was simulated with a fiber-gel finite element computational model that incorporates a three-layer vocal fold composition (superficial lamina propria, vocal ligament, thyroarytenoid muscle). Implants of various depths were simulated, with a "deeper" or more medial implant positioned closer to the vocal fold mucosa and replacing more muscle elements. Trajectories of surface and within-tissue nodal points during vibration were produced. Outcome measures were the trajectory radii, fundamental frequency (F₀ ), sound pressure level (SPL), and smoothed cepstral peak prominence (CPPS) as a function of implant depth.

RESULTS

Amplitude of vibration at the vocal fold medial surface was reduced by an implant depth of as little as 14% of the total transverse vocal fold depth. Increase in F₀ and decrease in CPPS were noted beyond 30% to 40% implant depth, and SPL decreased beyond 40% to 60% implant depth.

CONCLUSIONS

Commonly used implants can dampen vibration "from a distance," ie, even without being immediately adjacent to vocal fold mucosa. Since implants are typically placed at depths examined in this study, stiff implants likely have a negative vocal impact in a subset of patients. Softer materials may be preferable, especially in bilateral medialization procedures.

LEVEL OF EVIDENCE

N/A Laryngoscope, 130:2192-2198, 2020.

Practice variations in voice treatment selection following vocal fold mucosal resection

OBJECTIVES/HYPOTHESIS

To characterize initial voice treatment selection following vocal fold mucosal resection in a Medicare population.

STUDY DESIGN

Retrospective analysis of a large, nationally representative Medicare claims database.

METHODS

Patients with > 12 months of continuous Medicare coverage who underwent a leukoplakia- or cancer-related vocal fold mucosal resection (index) procedure during calendar years 2004 to 2009 were studied. The primary outcome of interest was receipt of initial voice treatment (thyroplasty, vocal fold injection, or speech therapy) following the index procedure. We evaluated the cumulative incidence of each postindex treatment type, treating the other treatment types as competing risks, and further evaluated postindex treatment utilization using the proportional hazards model for the subdistribution of a competing risk. Patient age, sex, and Medicaid eligibility were used as predictors.

RESULTS

A total of 2,041 patients underwent 2,427 index procedures during the study period. In 14% of cases, an initial voice treatment event was identified. Women were significantly less likely to receive surgical or behavioral treatment compared to men. From age 65 to 75 years, the likelihood of undergoing surgical treatment increased significantly with each 5-year age increase; after age 75 years, the likelihood of undergoing either surgical or behavioral treatment decreased significantly every 5 years. Patients with low socioeconomic status were significantly less likely to undergo speech therapy.

CONCLUSION

The majority of Medicare patients do not undergo voice treatment following vocal fold mucosal resection. Further, the treatments analyzed here appear disproportionally utilized based on patient sex, age, and socioeconomic status. Additional research is needed to determine whether these observations reflect clinically explainable differences or disparities in care.

LEVEL OF EVIDENCE

2c. Laryngoscope, 126:2505-2512, 2016.

Voice Outcomes following a Single Office-Based Steroid Injection for Vocal Fold Scar

OBJECTIVE

Persistent dysphonia from vocal fold scar remains a clinical challenge, with current therapies providing inconsistent outcomes. We evaluated voice outcomes after a single office-based steroid injection.

STUDY DESIGN

Case series with chart review.

SETTING

Academic medical center.

SUBJECTS AND METHODS

This study was based on pre- and postoperative analysis of patient-reported, perceptual, acoustic, aerodynamic, and videostroboscopic parameters. The sample comprised 25 patients undergoing office-based dexamethasone injection into the superficial lamina propria for mild/moderate vocal fold scar. Average follow-up was 13.7 ± 4.4 weeks; patients completed 3.5 ± 2.3 sessions of voice therapy between assessments. Complete data sets were not available for each parameter; sample size is noted with results.

RESULTS

Voice handicap index (n = 24; P < .001) and glottal function index (n = 22; P < .001) decreased after injection. Total GRBAS score (grade, roughness, breathiness, asthenia, strain) decreased (n = 25; P < .001). Fundamental frequency range increased (n = 24; P = .024). Phonation threshold pressure decreased (n = 14; P = .017). Videostroboscopic parameters of vocal fold edge (P = .004), glottic closure (P = .003), and right mucosal wave (P = .016) improved after injection.

CONCLUSIONS

Office-based steroid injection combined with voice therapy for mild/moderate vocal fold scar is associated with improved patient-reported and functional voice measures. These findings provide preliminary support for this approach. Importantly, the procedure is low risk and can be performed in the office, thus offering a simple treatment alternative to patients with a disorder that has traditionally been difficult to manage. Prospective studies evaluating the effects of multiple injections are warranted.

Evaluation of Heating and Shearing on the Viscoelastic Properties of Calcium Hydroxyapatite Used in Injection Laryngoplasty

OBJECTIVE

To compare the viscoelastic properties of calcium hydroxyapatite (CaHA) to carboxymethylcellulose (CMC) injectables used for injection laryngoplasty and determine if they are affected by heating and shearing.

STUDY DESIGN

Experimental.

SETTING

University laboratory.

SUBJECTS AND METHODS

Vocal fold injection laryngoplasty with CaHA is oftentimes challenging due to the amount of pressure necessary to push the injectate through a needle. Anecdotal techniques, such as heating the product, have been suggested to facilitate injection. The viscoelastic properties of CaHA and CMC were measured with a rheometer. The effects of heating and shearing on sample viscoelasticity were recorded.

RESULTS

CaHA was 9.5 times more viscous than CMC (43,100 vs 4540 Pa·s). Heating temporarily decreased the viscosity of CaHA by 32%. However, it also caused the viscosity to subsequently increase after time. Shearing of CaHA reduced its viscosity by 26%. Heating and shearing together temporarily reduced the viscosity of CaHA by 52%.

CONCLUSION

A combination of heating and shearing had a more profound effect than heating or shearing alone on the viscosity of CaHA, potentially making it easier to inject temporarily. Long-term and in vivo studies are required to further analyze the effect of heating and shearing on CaHA injectables.