Thyroplasty for unilateral vocal fold paralysis using an adjustable implant in porous titanium

Safety and Adverse Events of Medialization Thyroplasty: A Systematic Review

INTRODUCTION

Unilateral vocal fold paralysis or paresis (UVFP) is a condition that causes significant morbidity due to dysphonia, dysphagia, and aspiration. Type I medialization thyroplasty (MT) is the current mainstay surgical treatment for UVFP. Though widely considered a safe procedure, concerns exist over possible airway complications which can lead to overnight observation. Herein, we report a systematic review of the safety and adverse events of MT to aid in determining the safety of same-day discharge.

DATA SOURCES

PubMed and Embase databases.

REVIEW METHODS

Our search identified studies investigating complications associated with MT. Articles were selected if published between January 1, 1989 and March 15, 2023. Abstracts were screened, and data were extracted from included studies. Only Type I MT procedures were included; case reports were excluded. Participant characteristics, intervention details, results, and adverse events were extracted.

RESULTS

The database query identified 751 abstracts, of which 46 studies met eligibility criteria. A total of 2426 patients underwent MT. The most common implant was Silastic (n = 898, 37.0%) followed by Gore-Tex (n = 664, 27.4%). There were 254 (10.5%) total complications reported; 110 (4.5%) were considered major. The most common complication was nonobstructive hematoma (n = 59, 2.4%) followed by hemorrhage (n = 36, 1.5%). Implant extrusion (n = 24, 0.99%) or displacement (n = 15, 0.62%) occurred mostly in Silastic and Gore-Tex implants. Same-day discharge occurred with 429 patients and was not associated with adverse events.

CONCLUSIONS

UVFP can be reliably improved by MT with a low risk of complications. Outpatient MT is a promising treatment with a favorable safety profile. Laryngoscope, 134:1994-2004, 2024.

Long-term voice outcomes of medialization thyroplasty with adjustable implant for unilateral vocal fold paralysis

OBJECTIVES

Medialization thyroplasty (MT) using various implants has been employed as a corrective procedure for unilateral vocal fold paralysis (UVFP). A newly developed APrevent® vocal implant system (VOIS) offers an innovative solution with a finely adjustable design. This study aimed to investigate the long-term functional voice outcomes and benefits of postoperative adjustments in patients receiving MT using the VOIS-implant.

METHODS

This is a prospective case series study at single tertiary medical center. Fourteen adult patients diagnosed with UVFP received MT with the VOIS implant and were followed up for more than 1 year. Implant adjustment procedure by injecting 0.9% physiological saline solution was performed both during and after the surgery to optimize glottal closure and voice quality. Objective voice outcomes and acoustic parameters were assessed preoperatively and postoperatively at various timepoints.

RESULTS

Thirteen patients (93%) received intraoperative balloon adjustment, ranging from 0.05to 0.12 ml. Four patients underwent adjustments postoperatively and exhibited a positive trend towards immediately improving acoustic voice quality. Our long-term results demonstrated a notable improvement after the surgery in voice quality, with significant decreases in VHI-30 and improvements in perceptual parameters of GRBAS scale, acoustic measures such as jitter and signal-to-noise ratio (p < 0.001) and cepstral peak prominence smoothed in sustained vowel and short sentences. The voice outcomes remained stable more than 1 year follow-up.

CONCLUSIONS

Overall, MT with VOIS implantation provides a favorable long-term outcomes and stability in voice quality for patients with UVFP and also an effective tool for postoperative adjustment without major revision surgeries.

Effects of implant and vocal fold stiffness on voice production after medialization laryngoplasty in an MRI-based vocal fold model

Medialization laryngoplasty is one of the primary surgical interventions in the treatment of glottal insufficiency due to vocal fold paralysis, paresis, or atrophy. During the surgery, an implant is laterally inserted into the larynx to medialize the affected vocal fold toward glottal midline, with the goal of improving glottal closure during phonation and voice production efficiency. While implants of different materials and geometry designs have been used, the effect of implant design on the voice outcome remains unclear. In this simulation study, the effect of implant stiffness was investigated in an MRI-based model of the vocal folds after medialization laryngoplasty. The results showed that implant stiffness had a significant impact on the phonation threshold pressure, glottal area waveform, and fundamental frequency, but only small effect on the closed quotient and other acoustic measures of the produced voice. The effect of implant stiffness also exhibited variability, depending on the stiffness conditions of the vocal fold and paraglottic tissues, indicating that individual differences need to be considered during the planning of medialization laryngoplasty.

Active and Passive Bioimplants for Vocal Fold Paralysis

Vocal fold paralysis is one of the diseases that particularly affect quality of life. While unilateral paralysis leads to glottis closure insufficiency and hoarseness, bilateral paralysis compromises respiration and limits the exercise tolerance. Bioimplants have been used to treat persistent paralysis for over 100 years. The spectrum ranges from autologous tissue transfer and resorbable or permanent injection materials to composite thyroplasty implants and active electrical implants for neurostimulation of the larynx. If bioimplants are used in accordance with the recommendations, the quality of life of affected patients can be significantly improved today.

Vocal Fold Fat Augmentation for Atrophy, Scarring, and Unilateral Paralysis: Long-term Functional Outcomes

OBJECTIVE

There is a debate regarding the durability of fat implants. Our experience and recent publications suggest fat implantation may deliver a long-lasting improvement. This study aims to present the long-term outcomes for vocal fold fat augmentation using strict harvesting, preparing, and implantation protocols.

STUDY DESIGN

A prospective cohort conducted between 2014 and 2020 (recruitment 2014-2017).

SETTING

An academic tertiary referral center.

SUBJECTS AND METHODS

Twenty-two patients with glottic insufficiency were enrolled: 11 had unilateral vocal fold paralysis (UVFP), and 11 had atrophy or scar. Harvested fat was injected unilaterally or bilaterally into multiple sites. Six of these patients also had simultaneous microlaryngoscopic removal of other benign glottic lesions. Outcome measurements included video stroboscopy; Grade, Roughness, Breathiness, Asthenia, Strain (GRBAS) score; Voice Handicap Index (VHI); and acoustic analysis, performed preoperatively, 3, 12, 24, and 36 months after surgery.

RESULTS

Ten augmentations were unilateral and 12 bilateral. Comparing the preoperative and 36-month postoperative periods, the mean VHI score improved from 73.45 (±22.78) to 44.88 (±28.93), P = .001, and the mean GRBAS decreased from 8.64 (±3.89) to 2.82 (±2.3), P = .001; 24 months postoperatively, the mean fundamental frequency decreased from 163.88 Hz (±41.61) to 150.44 Hz (±41.47), P = .012. Stroboscopic analysis revealed statistically significant improvement in mucosal wave propagation, phase closure, and phase symmetry. Best results were achieved in the UVFP subgroup. Computed tomography scans demonstrated long-term viability of the implanted adipose tissue.

CONCLUSION

Fat is an excellent source of autologous graft. With careful patient selection and proper surgical technique, fat is suitable for long-term correction of glottic insufficiency. Fat augmentation should be considered as a long-lasting or even permanent solution, rather than temporary.

Pre- and intraoperative acoustic and functional assessment of the novel APrevent® VOIS implant during routine medialization thyroplasty

PURPOSE

Persistent unilateral vocal fold paralysis (UFVP) with glottal insufficiency often requires type I medialization thyroplasty (MT). Previous implants cannot be adjusted postoperatively if necessary. The newly developed APrevent^® VOIS implant (VOIS) can provide postoperative re-adjustment to avoid revision MT. The objective of this pilot study is to evaluate the VOIS intraoperatively concerning voice improvement, surgical feasibility and device handling.

METHODS

During routine MT, VOIS was applied short time in eight patients before the regular implantation of the Titanium Vocal Fold Medialization Implant (TVFMI™). In all patients, perceptual voice sound analysis using R(oughness)-B(reathiness)-H(oarseness)-scale, measurement of M(aximum)-P(honation)-T(ime) and glottal closure in videolaryngoscopy were performed before and after implanting VOIS/TVFMI™. Acoustic analyses of voice recordings were performed using freeware praat. Surgical feasibility, operative handling and device fitting of VOIS and TVFMI™ were assessed by the surgeon using V(isual)-A(nalog)-S(cale). Data were statistically analyzed with paired t test.

RESULT

All patients showed significant improvement of voice sound parameters after VOIS/TVFMI™ implantation. The mean RBH-scale improved from preoperative R = 2.1, B = 2.3, H = 2.5 to R = 0.6, B = 0.3, H = 0.8 after VOIS and R = 0.5, B = 0.3, H = 0.8 after TVFMI™ implantation. The mean MPT increased from preoperative 7.9 to 14.6 s after VOIS and 13.8 s after TVFMI™ implantation. VOIS/TVFMI™ achieved complete glottal closure in 7/8 patients. The satisfaction with intraoperative device fitting and device handling of VOIS was as good as that of TVFMI™.

CONCLUSION

The novel APrevent^® VOIS implant showed similar intraoperative voice improvement compared to routinely used TVFMI™ without adverse device events and with safe device fitting.

Voice outcome indicators for unilateral vocal fold paralysis surgery: a review of the literature

INTRODUCTION

There is no consensus on which voice outcome indicators (VOIs) should be used to compare the merits of the various surgical treatments for unilateral vocal fold paralysis (UVFP). Authors performed a literature review to identify which VOIs are most frequently used and most relevant, in terms of significant change in pre- and post-operative measurements, to assess UVFP surgical treatments.

METHOD

A Medline/Pubmed literature review was performed and the most frequently used VOIs were identified using a Pareto diagram. For these most frequently used VOI's, the number of studies that showed a statistically significant change in pre- and post-operative results were compared to the total number of studies found using that same VOI, this portion was expressed in percent. This percentage was defined as the "percentage of significance" and used to assess changes of each VOI.

RESULTS

Eleven VOIs were identified using the Pareto analysis. These were, in decreasing order of frequency of citation: maximum phonation time (MPT), jitter, Shimmer, video-stroboscopic examination, noise to harmonic ratio (NHR/HNR), mean air flow (MeAF), fundamental frequency (F0), "Infrequent Perceptional Scales", GRBAS scale, mean subglottic pressure (MSGP). MPT, MeAF, factor G of GRBAS-I, Jitter, shimmer and VHI-30 had respective "percentage of significance" of 90, 86, 85, 74, 68 and 64%, respectively.

CONCLUSION

The results indicate that MPT, MeAF and GRBAS-I, represent the top-three most frequently used and the most relevant VOIs in terms of "percentage of significance". VHI-30 showed a relatively low rate of use and low "percentage of significance". The role of Jitter and Shimmer remains unclear. Finally, MSGP and the F0 appear to be less relevant VOIs for the evaluation of UFVP surgical treatments in terms of significant change in pre- and post-operative measurements.

Excised larynx evaluation of subthyroid cartilage approach to medialization thyroplasty

OBJECTIVES/HYPOTHESIS

To describe an alternative approach to medialization thyroplasty involving dissection underneath the thyroid cartilage with placement of a Gore-Tex implant, and to evaluate its effect on a range of phonatory measures using an excised canine larynx model.

STUDY DESIGN

Animal model.

METHODS

On each of eight excised canine larynges, the conditions of normal, paralysis, medialization thyroplasty by standard transthyroid cartilage approach, and medialization thyroplasty by experimental subthyroid cartilage approach were performed. Aerodynamic, acoustic, and mucosal wave parameters were measured for each condition.

RESULTS

Compared to the vocal fold paralysis state, both the transthyroid and subthyroid approaches for Gore-Tex insertion resulted in significant decreases in phonation threshold pressure and phonation threshold flow. Both approaches also significantly decreased percent jitter, decreased percent shimmer, and improved signal-to-noise ratio. The mucosal wave was preserved after insertion of the Gore-Tex implant for both approaches. For all the phonatory measures except phonation threshold flow, there were no significant differences between the transthyroid and subthyroid approaches.

CONCLUSIONS

Gore-Tex implantation via a subthyroid approach in an excised canine larynx model can produce effective medialization, preserve the mucosal wave, and significantly improve aerodynamic and acoustic parameters without meaningful difference compared to a traditional transthyroid approach. The subthyroid approach does not require creation of a thyroid cartilage window and could be a potentially valuable alternative method of performing medialization thyroplasty.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:675-681, 2018.

[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.

Phonatory effects of type I thyroplasty implant shape and depth of medialization in unilateral vocal fold paralysis

OBJECTIVES/HYPOTHESIS

Medialization thyroplasty (MT) is commonly used to treat glottic insufficiency. In this study, we investigated the phonatory effects of MT implant medialization depth and medial surface shape.

METHODS

Recurrent laryngeal nerve (RLN) and vagal paralysis were simulated in an in vivo canine. A type 1 MT was performed using a silicone elastomer implant with variable medialization depths and medial surface shapes: rectangular, V-shaped, divergent, and convergent. The effects on phonation onset flow/pressure relationships and acoustics were measured.

RESULTS

Increasing depth of medialization led to improvements in fundamental frequency (F0) range and normalization of the slope of pressure/flow relationship toward baseline activation conditions. The effects of implant medial shape also depended on depth of medialization. Outcome measures were similar among the implants at smaller medialization depths. With large medialization depths and vagal paralysis conditions, the divergent implant maintained pressure/flow relationship closer to baseline. The vagal paralysis conditions also demonstrated decreased fundamental frequency range and worse flow/pressure relationship compared to RLN paralysis.

CONCLUSIONS

The depth and medial shape of a medialization laryngoplasty (ML) implant significantly affect both the F0 range and aerodynamic power required for phonation. These effects become more notable with increasing depth of medialization. The study also illustrates that ML is less effective in vagal paralysis compared to RLN paralysis.

LEVEL OF EVIDENCE

N/A.