Functional outcome of vocal fold medialization thyroplasty with a hydroxyapatite implant

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.

Care and Management of Voice Change for Thyroid Surgery: Korean Society of Laryngology, Phoniatrics and Logopedics Clinical Practice Guideline

Voice change is a common complaint after thyroid surgery and has significant impacts on quality of life. The Korean Society of Laryngology, Phoniatrics, and Logopedics set up a task force team to establish guideline recommendations on education, care, and management related to thyroid surgery. The guideline recommendations include preoperative voice education, management of anticipated voice change during surgery, and comprehensive voice care after thyroid surgery, including in-depth information and up-to-date knowledge based on validated literature. The committee constructed 14 key questions (KQ) in three categories: preoperative (KQ1-2), intraoperative (KQ 3-8), and postoperative (KQ 9-14) management and developed 18 evidence-based recommendations. The Delphi survey reached an agreement on each recommendation. Detailed evidence profiles are presented for each recommendation. The level of evidence for each recommendation is classified into high, moderate, and low-quality. The recommendation's strengths are adjusted to consider the level of evidence resulting in the recommendation and are divided into strong and weak. The guidelines are primarily targeted toward physicians who treat thyroid surgery patients and speech-language pathologists participating in patient care. These guidelines will also help primary care physicians, nurses, healthcare policymakers, and patients improve their understanding of voice changes and voice care after thyroid surgery.

Data Collection Methods for the Voice Range Profile: A Systematic Review

Purpose To assess data collection variability in the voice range profile (VRP) across clinicians and researchers, a systematic review was conducted to evaluate the extent of variability of specific data collection points that affect the determination of frequency range and sound level and determine next steps in standardization of a VRP protocol. Method A systematic review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis checklist. Full-text journal articles were identified through PubMed, Web of Science, Psych Info, ProQuest Dissertations and Theses Global, Google Scholar, and hand searching of journals. Results A total of 1,134 articles were retrieved from the search; of these, 463 were duplicates. Titles and abstracts of 671 articles were screened, with 202 selected for full-text review. Fifty-four articles were considered eligible for inclusion. The information extracted from these articles revealed the methodology used to derive the VRP was extremely variable across the data points selected. Additionally, there were eight common acoustic measures used for statistical analysis described in included studies that were added as a data point. Conclusions The data collection methods for the VRP varied considerably. Standardization of procedures was recommended for clinicians and researchers.

Transoral laser microsurgery for polydimethylsiloxane (VOX Implant®) explantation

INTRODUCTION

Polydimethylsiloxane (VOX Implant®) injection into the larynx is a surgical technique used to restore volume to paralysed or atrophic vocal folds. We present a case series that demonstrates the feasibility of explantation of this non-resorbable material in the event of complications secondary to this injection.

DESCRIPTION

We report four cases of VOX Implant® explantation. In every case, explantation was performed following complications such as dysphonia and/or dyspnoea secondary to injection of this material. VOX Implant® explantation was performed via cordotomy using transoral lasermicrosurgical techniques.

DISCUSSION

VOX Implant® explantation improved voice and breathing parameters in all patients. Explantation can be performed by transoral microsurgery in the presence of complications related to polydimethylsiloxane injection.

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.

Stroboscopic assessment of unilateral vocal fold paralysis: a systematic review

PURPOSE

To review the relevant basic stroboscopic evaluations in unilateral vocal fold paralysis (UVFP). Our aim was twofold: (1) to determine the frequency of use of stroboscopic parameters in outcome evaluation after surgical treatment of UVFP using a Pareto diagram; and (2) to select the most relevant parameters in terms of a significant difference between pre- and post-surgical intervention for UVFP.

METHODS

A systematic review in PUBMED includes studies on stroboscopic evaluation in combination with UVFP and surgical treatment. The review was limited to English studies published between 1990 and March 2018. The most frequently used stroboscopic parameters were identified using a Pareto diagram. Then, 'the percentage of significance' for the most frequently stroboscopic parameters was identified by comparing the number of studies that showed a statistically significant change in pre- and post-treatment results with the total number of studies using the same parameters.

RESULTS

Seven stroboscopic parameters were nominated using the Pareto diagram. In decreasing order of citation frequency, periodicity, edge bowing, mucosal wave, glottic gap, position of vocal fold, amplitude, and symmetry have respective percentages of significance of 87.5%, 83.3%, 77.7%, 64.5%, 60%, 57.1%, and 50%. Five pertinent scales were selected for the most frequent and significant stroboscopic parameters.

CONCLUSIONS

The results indicate that periodicity, edge bowing, mucosal wave, glottic gap, and position of vocal fold represent the five most frequently used and relevant stroboscopic parameters in UVFP evaluation. The current review outlines a proposal scale of these stroboscopic parameters.

PROSPERO REGISTRATION NUMBER

CRD42019126786.

Parameters and Scales Used to Assess and Report Findings From Stroboscopy: A Systematic Review

OBJECTIVE

Laryngeal endoscopy with stroboscopy, a critical component of the assessment of voice disorders, is rarely used as a treatment outcome measure in the scientific literature. We hypothesized that this is because of the lack of a widely used standardized, validated, and reliable method to assess and report laryngeal anatomy and physiology, and undertook a systematic literature review to determine the extent of the inconsistencies of the parameters and scales used in voice treatment outcome studies.

STUDY DESIGN

Systematic literature review.

METHODS

We searched PubMed, Ovid, and Cochrane for studies where laryngeal endoscopy with stroboscopy was used as a treatment outcome measure with search terms representing "stroboscopy" and "treatment" guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards.

RESULTS

In the 62 included articles, we identified 141 terms representing 49 different parameters, which were further classified into 20 broad categories. The six most common parameters were magnitude of glottal gap, mucosal wave amplitude, location or shape of glottal gap, regularity of vibration, phase symmetry, and presence and size of specific lesions. Parameters were assessed on scales ranging from binary to 100 points. The number of scales used for each parameter varied from 1 to 24, with an average of four different scales per parameter.

CONCLUSIONS

There is a lack of agreement in the scientific literature regarding which parameters should be assessed to measure voice treatment outcomes and which terms and scales should be used for each parameter. This greatly diminishes comparison and clinical implementation of the results of treatment outcomes research in voice disorders. We highlight a previously published tool and recommend it for future use in research and clinical settings.

The use of injectable calcium hydroxylapatite in the surgically pretreated larynx with glottal insufficiency

OBJECTIVES/HYPOTHESIS

To evaluate the efficacy of vocal fold (VF) augmentation with calcium hydroxylapatite (CaHA) microspheres in the surgically pretreated larynx with glottal insufficiency.

STUDY DESIGN

Prospective clinical pilot study.

METHODS

After several prior reconstructive attempts (following tumor resection, VF paralysis, in sulcus vocalis, and VF scarring), CaHA was injected under general anaesthesia using a transoral microlaryngoscopic approach in 10 patients with residual glottal insufficiency ≤1.5 mm. The postinterventional result was assessed after 1 day, and 1 and 3 months. Evaluation of augmentation comprised intraoperative video/photo documentation, pre-/postoperative videolaryngostroboscopy, as well as established subjective and objective voice function diagnostics (Grade, Roughness, Breathiness [GRB] Scale; Voice Handicap Index; voice range profile; and acoustic-aerodynamic analysis).

RESULTS

In the pretreated VF with no or minimal lamina propria remaining, the exact placement of CaHA was not possible due to unpredictable propagation into the scarred tissue. The results showed an insufficient postoperative augmentation. Accordingly, the voice function did not improve. However, a significant increase of the vocal range from 6.2 ± 3.2 to 8.7 ± 3.9 semitones was observed in the speaking voice profile (P =.02). All other acoustic and aerodynamic parameters remained on the whole unchanged; the slight differences between pre- and postoperative findings were not significant.

CONCLUSIONS

The application of CaHA in the surgically pretreated scarred larynx is not reliable to achieve a sufficient glottal closure and a satisfactory improvement of voice. Though CaHA is a welcome addition to our armamentarium against glottal insufficiency, the suitability for augmentation of scar tissue in the larynx must be considered carefully in each individual case.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:1125-1130, 2017.

[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.

[Treatment of glottal gap]

Glottal gaps can be either physiological or pathological. The latter are multifactorial, predominantly organic in origin and occasionally functional. Organic causes include vocal fold paralysis or scarring, as well as a deficiency or excess of tissue. In addition to loss of the mucosal wave, the degree of hoarseness is primarily determined by the circumferential area of the glottal gap. It is thus important to quantify the extent of glottal insufficiency. Although a patient's symptoms form the basis for treatment decisions, these may be subjective and inadequately reflected by the results of auditory-perceptual evaluation, voice analysis and voice performance tests. The therapeutic approach should always combine phonosurgery with conventional voice therapy methods. Voice therapy utilises all the resources made available by the sphincter model of the aerodigestive tract and knowledge on the mechanism of voice production. The aim of phonosurgery is medialization, reconstruction or reinnervation by injection laryngoplasty or larynx framework surgery. These different methods can be combined and often applied directly after vocal fold surgery (primary reconstruction). In conclusion, the techniques described here can be effectively employed to compensate for glottal gaps.

Phase stability and rapid consolidation of hydroxyapatite–zirconia nano-coprecipitates made using continuous hydrothermal flow synthesis

A rapid and continuous hydrothermal route for the synthesis of nano-sized hydroxyapatite rods co-precipitated with calcium-doped zirconia nanoparticles using a superheated water flow at 450°C and 24.1 MPa as a crystallizing medium is described. Hydroxyapatite and calcium-doped zirconia phases in the powder mixtures could be clearly identified based on particle size and morphology under transmission electron microscopy. Retention of a nanostructure after sintering is crucial to load-bearing applications of hydroxyapatite-based ceramics. Therefore, rapid consolidation of the co-precipitates was investigated using a spark plasma sintering furnace under a range of processing conditions. Samples nominally containing 5 and 10 wt% calcium-doped zirconia and hydroxyapatite made with Ca:P solution molar ratio 2.5 showed excellent thermal stability (investigated using in situ variable temperature X-ray diffraction) and were sintered via spark plasma sintering to >96% sintered densities at 1000°C resulting in hydroxyapatite and calcium-doped zirconia as the only two phases. Mechanical tests of spark plasma sintering sintered samples (containing 10 wt% calcium-doped zirconia) revealed a three-pt flexural strength of 107.7 MPa and Weibull modulus of 9.9. The complementary nature of the spark plasma sintering technique and continuous hydrothermal flow synthesis (which results in retention of a nanostructure even after sintering at elevated temperatures) was hence showcased.

Medialization thyroplasty using autologous nasal septal cartilage for treating unilateral vocal fold paralysis

Objectives

A persistent insufficiency of glottal closure is mostly a consequence of impaired unilateral vocal fold movement. Functional surgical treatment is required because of the consequential voice, breathing and swallowing impairments. The goal of the study was to determine the functional voice outcomes after medialization thyroplasty with using autologous septal cartilage from the nose.

Methods

External vocal fold medialization using autologous nasal septal cartilage was performed on 15 patients (6 females and 9 males; age range, 30 to 57 years). Detailed functional examinations were performed for all the patients before and after the surgery and this included perceptual voice assessment, laryngostroboscopic examination and acoustic voice analysis.

Results

All the patients reported improvement of voice quality post-operatively. Laryngostroboscopy revealed almost complete glottal closure after surgery in the majority of patients. Acoustic and perceptual voice assessment showed significant improvement post-operatively.

Conclusion

Medialization thyroplasty using an autologous nasal septal cartilage implant offers good tissue tolerability and significant improvement of the subjective and objective functional voice outcomes.

High-strength nanograined and translucent hydroxyapatite monoliths via continuous hydrothermal synthesis and optimized spark plasma sintering

The synthesis of high-strength, completely dense nanograined hydroxyapatite (bioceramic) monoliths is a challenge as high temperatures or long sintering times are often required. In this study, nanorods of hydroxyapatite (HA) and calcium-deficient HA (made using a novel continuous hydrothermal flow synthesis method) were consolidated using spark plasma sintering (SPS) up to full theoretical density in ∼5 min at temperatures up to 1000°C. After significant optimization of the SPS heating and loading cycles, fully dense HA discs were obtained which were translucent, suggesting very high densities. Significantly high three-point flexural strength values for such materials (up to 158 MPa) were measured. Freeze-fracturing of disks followed by scanning electron microscopy investigation revealed selected samples possessed sub-200 nm sized grains and no visible pores, suggesting they were fully dense.