Adult cavernous haemangioma of the vocal cords with a unique presentation of acute respiratory distress: a case report

Laryngeal haemangiomas can commonly be seen in children, and first-line treatment is usually propranolol. However, in adults, cavernous haemangioma of the vocal cord(s) is an extremely rare condition - with this being the only published adult case presenting with acute respiratory distress - the mainstay of treatment is surgical excision under microlaryngoscopy. Presentation in adults can be unpredictable, but primarily consists of hoarseness which can be associated with, dyspnoea, dysphagia, and haemoptysis - and in one documented case stenosis of the aero-digestive tract led to death. Due to these airway difficulties, surgery can often prove challenging. In this study, we explore the unusual case of a previously well 71-year-old gentleman presenting to the Emergency Department, with worsening shortness of breath as his primary complaint. Uniquely, in this case, an awake fibre-optic intubation was undertaken to manage the difficult airway and a microlaryngoscopy was performed. A 20x10x15mm lesion was excised, which had characteristics in keeping with a cavernous haemangioma on microscopic examination.

Glottal Airflow and Glottal Area Waveform Characteristics of Flow Phonation in Untrained Vocally Healthy Adults

OBJECTIVE

To examine flow phonation characteristics with regard to vocal fold vibration and voice source properties in vocally healthy adults using multimodality voice measurements across various phonation types (breathy, neutral, flow, and pressed) and loudness conditions (typical, loud, and soft).

PARTICIPANTS AND METHODS

Vocal fold vibration, airflow, acoustic, and subglottal pressure was analyzed in 13 untrained voices (six female and seven male). Participants repeated the syllable / pæ:/ using breathy, neutral, flow, and pressed phonation during typical, loud, and soft loudness conditions. Glottal area (GA) waveforms were extracted from high-speed videoendoscopy; glottal flow was derived from inverse filtering the airflow or the audio signal; and subglottal pressure was measured as the intraoral pressure during /p/ occlusion.

RESULTS

Changes in phonation type and loudness conditions resulted in systematic variations across the relative peak closing velocity derived from the GA waveform for both males and females. Amplitude quotient derived from the flow glottogram varied across phonation types for males.

CONCLUSION

Multimodality evaluation using the GA waveform and the inverse filtered waveforms revealed a complex pattern that varied as a function of phonation types and loudness conditions across males and females. Emerging findings from this study suggests that future large-scale studies should focus on spatial and temporal features of closing speed and closing duration for differentiating flow phonation from other phonation types in untrained adults with and without voice disorders.

Indicators of anterior-posterior phase difference in glottal opening measured from natural production of vowels

Voiced speech is generated by the glottal flow interacting with vocal fold vibrations. However, the details of vibrations in the anterior-posterior direction (the so-called zipper-effect) and their correspondence with speech and other glottal signals are not fully understood due to challenges in direct measurements of vocal fold vibrations. In this proof-of-concept study, the potential of four parameters extracted from high-speed videoendoscopy (HSV), electroglottography, and speech signals to indicate the presence of a zipper-type glottal opening is investigated. Comparison with manual labeling of the HSV videos highlighted the importance of multiple parameter-signal pairs in indicating the presence of a zipper-type glottal opening.

Laryngeal strategies to minimize vocal fold contact pressure and their effect on voice production

The goal of this study is to identify laryngeal strategies that minimize vocal fold contact pressure while producing a target sound pressure level (SPL) using a three-dimensional voice production model. The results show that while the subglottal pressure and transverse stiffness can be manipulated to reduce the peak contact pressure, such manipulations also reduce the SPL, and are thus less effective in reducing contact pressure in voice tasks targeting a specific SPL level. In contrast, changes in the initial glottal angle and vocal fold vertical thickness that reduce the contact pressure also increase the SPL. Thus, in voice tasks targeting a specific SPL, such changes in the initial glottal angle and vertical thickness also lower the subglottal pressure, which further reduces the peak contact pressure. Overall the results show that for voice tasks with a target SPL level, vocal fold contact pressure can be significantly reduced by adopting a barely abducted glottal configuration or reducing the vocal fold vertical thickness. Aerodynamic measures are effective in identifying voice production with large initial glottal angles, but by themselves alone are not useful in differentiating hyperadducted vocal folds from barely abducted vocal folds, which may be better differentiated by closed quotient and voice type measures.

The assessment of phonatory and ventilatory functions in patients after microsurgery for Reinke's edema

BACKGROUND

Short and long-term results of microsurgical treatment with the mini-microflap technique in patients with Reinke's edema (RE) were assessed based on the phonatory and ventilatory functions of the larynx.

OBJECTIVES

To assess the short and long-term results of microsurgical treatment with the mini-microflap technique in patients with RE based on the phonatory and ventilatory functions of the larynx.

MATERIAL AND METHODS

Twenty patients diagnosed with advanced stage of RE confirmed with laryngovideostroboscopy (LVS) were enrolled in the study. Phonatory function disturbances were additionally assessed on the basis of Maximum Phonation Time (MPT) measurement, Voice Handicap Index (VHI) and Voice-Related Quality of Life (V-ROOL) questionnaires. Ventilatory function was assessed using spirometry. The aforementioned complex examinations were conducted prior to surgery and 1, 6 and 9 months following the surgery.

RESULTS

Good postsurgical results were obtained in subjective and objective evaluation, which assessed the phonatory function and ventilatory parameters. Post-surgery increase in MPT, VHI and VQROL was noticed in all patients in 3 check points (p < 0.001). The results demonstrate postsurgical improvement for some LVS parameters, including assessment of glottis closure (p < 0.003) observed 6 months after the surgery. An improvement in most of the ventilation parameters was observed also 6 months after surgery (p < 0.001). For the spirometry flow parameter PEF, significant improvement was noted in each check point (p1 < 0.004, p6 < 0.001, p9 < 0.001). The study revealed a correlation between phonatory parameter - MPT and PEF observed 1 month after the procedure (p = 0.026), confirming the interdependence of ventilatory efficiency and phonatory condition of larynx.

CONCLUSIONS

Mini-microflap surgery brings satisfactory clinical effect in patients with advanced stages of RE by optimization of phonatory and ventilatory functions of the larynx.

[Clinical diagnosis and treatment of 157 cases of vocal leukoplakia]

Objective:To study the clinical characteristics and common etiology of vocal cord leukoplakia, and explore the treatment principle. Method:One hundred and fifty-seven patients with vocal cord leukoplakia were recruited in this study. They were assessed by routine laryngoscope, narrow band imaging （NBI）, stroboscope, reflux finding score （RFs） and reflux symptom index （RSI）, and given conservative treatment （smoking cessation, alcohol, acid suppression, sound cessation, etc.） and/or surgical treatment. Result:Among 157 patients with leukoplakia of vocal cord, 109 （69.4%） had basically improved or cured after conservative treatment. Forty-eight cases underwent operation. The postoperative pathological diagnosis was mild dysplasia in 2 cases （1.3%）, moderate dysplasia in 15 cases （9.6%）, severe dysplasia or carcinoma in situ in 19 cases （12.1%）, and invasive carcinoma in 12 cases （7.6%）. Conclusion:NBI and stroboscopic laryngoscopy showed that most of the leukoplakia of vocal cord was non-malignant in nature, which was not in accordance with the indication of operation. Conservative treatment is effective. Biopsy or operation was indicated in only a few patients. Moreover, most of the patients are accompanied by laryngopharyngeal reflux, and the treatment of acid suppression is effective.

Analysis of the tonal sound generation during phonation with and without glottis closure

The human phonation is characterized by periodical oscillations of the vocal folds with a complete glottis closure. In contrast, a glottal insufficiency (GI) represents an oscillation without glottis closure resulting in a breathy and weak voice. In this study, flow-induced oscillations of silicone vocal folds were modeled with and without glottis closure. The measurements comprised the flow pressure in the model, the generated sound, and the high-speed footage of the vocal fold motion. The analysis revealed that the sound signal for vocal fold oscillations without closure exhibits a lower number of harmonic tones with smaller amplitudes compared to the case with complete closure. The time series of the pressure signals showed small and periodical oscillations occurring less frequently and with smaller amplitude for the GI case. Accordingly, the pressure spectra include fewer harmonics similar to the sound. The analysis of the high-speed videos indicates that the strength of the pressure oscillations correlates with the divergence angle of the glottal duct during the closing motion. Physiologically, large divergence angles typically occur for a pronounced mucosal wave motion with glottis closure. Thus, the results indicate a correlation between the intensity of the mucosal wave and the development of harmonic tones.

Bayesian estimation of vocal function measures using laryngeal high-speed videoendoscopy and glottal airflow estimates: An in vivo case study

This study introduces the in vivo application of a Bayesian framework to estimate subglottal pressure, laryngeal muscle activation, and vocal fold contact pressure from calibrated transnasal high-speed videoendoscopy and oral airflow data. A subject-specific, lumped-element vocal fold model is estimated using an extended Kalman filter and two observation models involving glottal area and glottal airflow. Model-based inferences using data from a vocally healthy male individual are compared with empirical estimates of subglottal pressure and reference values for muscle activation and contact pressure in the literature, thus providing baseline error metrics for future clinical investigations.

A Preliminary Study on Automatic Characterization and Classification of Vascular Patterns of Contact Endoscopy Images

The structure and organization of blood vessels in the vocal fold go through changes during the advancement from healthy to benign and further on to malignant stages. Contact Endoscopy (CE) is an optical technique providing real-time information related to the vascular structure of laryngeal mucosa. However, this technique comes with subjectivity in the interpretation of vascular patterns. In this study, a novel automated approach is proposed for vessel pattern charac-terization and classification of larynx CE + Narrow Band Imaging (NBI) images. This method is mainly based on the computation of indicators related to the level of disorder of vessels. 12 features were extracted from the indicators and were fed into two supervised classifiers. Linear Support Vector Machine (SVM) and K-Nearest Neighbor (KNN) showed an accuracy of 95.76% and 93.92% for vascular patterns and 86.04% and 82.23% for larynx histopathologies classification, respectively. These promising results show that the proposed method can potentially solve the subjectivity issues of CE.

Mycosis Fungoides of the True Vocal Folds: A Case Report

OBJECTIVES

To report a case of laryngeal involvement of mycosis fungoides and its symptomatic treatment with laser-assisted surgical ablation.

METHODS

Case report and literature review.

RESULTS

A 76-year-old woman with longstanding MF previously treated with Brentuximab Vedotin who developed persistent cough and dysphonia. The patient's laryngeal disease burden was treated with KTP-laser ablation and further reduced with doxorubicin and radiotherapy.

CONCLUSIONS

Although laryngeal, and especially glottic, involvement is a rare finding, suspicion should be maintained in symptomatic patients with cutaneous mycosis fungoides. This the first reported surgical laser treatment of laryngeal symptoms in this context, which can greatly improve a patient's quality of life.

3D-Printed Synthetic Vocal Fold Models

OBJECTIVE

Synthetic vocal fold (VF) models used for studying the physics of voice production are comprised of silicone and fabricated using traditional casting processes. The purpose of this study was to develop and demonstrate a new method of creating synthetic VF models through 3D printing in order to reduce model fabrication time, increase yield, and lay the foundation for future models with more life-like geometric, material, and vibratory properties.

STUDY DESIGN

Basic science.

METHODS

A 3D printing technique based on embedding a UV-curable liquid silicone into a gel-like medium was selected and refined. Cubes were printed and subjected to tensile testing to characterize their material properties. Self-oscillating VF models were then printed, coated with a thin layer of silicone representing the epithelium, and used in phonation tests to gather onset pressure, frequency, and amplitude data.

RESULTS

The cubes were found to be anisotropic, exhibiting different modulus values depending on the orientation of the printed layers. The VF models self-oscillated and withstood the strains induced by phonation. Print parameters were found to affect model vibration frequency and onset pressure. Primarily due to the design of the VF models, their onset pressures were higher than what is found in human VFs. However, their frequencies were within a comparable range.

CONCLUSION

The results demonstrate the ability to 3D print synthetic, self-oscillating VF models. It is anticipated that this method will be further refined and used in future studies exploring flow-induced vibratory characteristics of phonation.

Paradoxical Vocal Fold Motion in Difficult Asthma Is Associated with Dysfunctional Breathing and Preserved Lung Function

BACKGROUND

Many patients with difficult asthma also have coexisting vocal cord dysfunction (VCD), evident by paradoxical vocal fold motion (PVFM) on laryngoscopy.

OBJECTIVE

Among patients with difficult asthma, we sought to identify clinical features associated with laryngoscopy-diagnosed PVFM.

METHODS

Consecutive patients with "difficult asthma" referred by respiratory specialists underwent systematic assessment in this observational study. Those with a high clinical suspicion for VCD were referred for laryngoscopy, either at rest or after mannitol provocation. Statistical analyses were performed to identify clinical factors associated with PVFM, and a multivariate logistic regression model was fitted to control for confounders.

RESULTS

Of 169 patients with difficult asthma, 63 (37.3%) had a high clinical probability of VCD. Of 42 who underwent laryngoscopy, 32 had PVFM confirmed. Patients with PVFM more likely had preserved lung function (prebronchodilator forced expiratory ratio 74% ± 11 vs 62% ± 16, P < .001); physiotherapist-confirmed dysfunctional breathing (odds ratio [OR] = 5.52, 95% confidence interval [CI]: 2.4-12.7, P < .001), gastro-oesophageal reflux (OR = 2.6, 95% CI: 1.16-5.8, P = .02), and a lower peripheral eosinophil count (0.09 vs 0.23, P = .004). On multivariate logistic regression, independent predictors for PVFM were dysfunctional breathing (OR = 4.93, 95% CI: 2-12, P < .001) and preserved lung function (OR = 1.07, 95% CI: 1.028-1.106, P < .001).

CONCLUSION

Among specialist-referred patients with difficult asthma, VCD pathogenesis may overlap with dysfunctional breathing but is not associated with severe airflow obstruction. Dysfunctional breathing and preserved lung function may serve as clinical clues for the presence of VCD.

Estimation of vocal fold physiology from voice acoustics using machine learning

The goal of this study is to estimate vocal fold geometry, stiffness, position, and subglottal pressure from voice acoustics, toward clinical and other voice technology applications. Unlike previous voice inversion research that often uses lumped-element models of phonation, this study explores the feasibility of voice inversion using data generated from a three-dimensional voice production model. Neural networks are trained to estimate vocal fold properties and subglottal pressure from voice features extracted from the simulation data. Results show reasonably good estimation accuracy, particularly for vocal fold properties with a consistent global effect on voice production, and reasonable agreement with excised human larynx experiment.

Phonation threshold pressure using a 3-mass model of phonation with empirical pressure values

Understanding the control parameters that influence phonation threshold pressure can have important implications for ease of phonation. Using a computer model of phonation can aid in studying parameters not easily controllable through human experimental work and may provide a means of explaining variations seen across human participants. A vertical 3-mass computer model of phonation with empirical driving pressures was used to obtain phonation threshold pressures for a variety of prephonatory conditions that may be realistically produced by humans. The resulting phonation threshold pressures are reasonable compared to results from human studies and may extend beyond the range of phonatory control parameters studied in human experiments. In addition, the present work adds a formula for calculating phonation threshold pressure based on the prephonatory glottal angle, the tension of the vocal folds, and the prephonatory diameter. Of special interest is that, as the prephonatory angle of convergence increases from 0 degrees (the rectangular glottis condition), the phonation threshold pressure increases in a nearly linear fashion.

[Preliminary study of medialization thyroplasty for unilateral vocal fold immobility]

Objective:To explore the feasibility and effectiveness of medialization thyroplasty for the treatment of unilateral vocal fold immobility （UVFI）. Method:Eight UVFI patients were performed medialization thyroplasty under local anesthesia. We made a window in the thyroid cartilage under local anesthesia, then insert the preformed silicone implant. The paralyzed vocal fold was medialized to make the glottis closed. Fibrolaryngoscope video recording, subjective voice analysis and CT thin slice scan of larynx were done before and after surgery to evaluate closure of vocal cords, improvement of voice and position of implantation. Result:The preoperative and postoperative voice handicap index 30（VHI-30） of the 8 patients were 91.5（64.5, 97.5） and 22.5（5.0, 47.5） respectively, which showed statistical difference（P<0.05）. GRBAS results: The postoperative G, R, B, A were all smaller than preoperative ones, which showed statistical difference（P<0.05）; the pre and postoperative S was both 0. The fibrolaryhgoscope recording showed the preoperative and postoperative score of incomplete glottis closure was 1.0（1.0, 1.0） and 4.0（2.5, 5.0） respectively, which showed statistical difference（P<0.05）. Postoperative laryngeal CT showed significant vocal cord medialization on the affected side. Aspiration was significantly improved in 4 patients who were suffered from this symptom before the surgery. No complication occurred with the 8 patients during 5 to 48 months follow up. Conclusion:Medialization thyroplasty can effectively improve vocalization and quality of life in patients with UVFI.

The impact of a standardized vocal loading test on vocal fold oscillations

Introduction

Vocal loading capacity is an important aspect of vocal health and is measured using standardized vocal loading tests. However, it remains unclear how vocal fold oscillation patterns are influenced by a standardized vocal loading task.

Methods

21 (10 male, 11 female) vocally healthy subjects were analyzed concerning the dysphonia severity index (DSI) and high speed videolaryngoscopy (HSV) on the vowel /i/ at a comfortable pitch and loudness before and after a standardized vocal loading test (10 min standardized text reading, at a level higher than 80 dB (A) measured at 30 cm from the mouth).

Results

Changes in DSI were statistically significant, diminishing by 1.2 points after the vocal loading test, which was mainly caused by an increase of the minimum intensity. However, the pre-post comparison of HSV derived measures failed to show any statistically significant changes.

Conclusion

It seems necessary to analyze the effects of a standardized vocal loading test on vocal fold oscillation patterns with respect to softest phonation and phonation threshold pressure rather than comfortable pitch and loudness.

Level of evidence

2c

A closed claims analysis of vocal cord injuries related to endotracheal intubation between 2004 and 2015

STUDY OBJECTIVE

To provide a contemporary medicolegal analysis of claims brought against anesthesiologists for injuries related to endotracheal intubation.

DESIGN

A retrospective study of closed claims data from the Controlled Risk Insurance Company (CRICO) Comparative Benchmarking System (CBS) database between 2004 and 2015.

SETTING

Closed claims that occurred in any surgical specialty in which the patient was undergoing general anesthesia and anesthesiology was named as the primary responsible service.

PATIENTS

Twenty claims were identified for analysis in 7 surgical specialties. Patient ages ranged from 45 to 76. Data regarding patient comorbidities and case history were obtained when available.

INTERVENTIONS

None.

MEASUREMENTS

Data collected includes patient demographics such as age, outcome severity, alleged complication, plaintiff allegations, contributing factors to the injury, the surgical specialty in which the injury occurred, and the ultimate result of the claim (dismissed/denied/settled).

MAIN RESULTS

Out of 20 claims, settlement payments were made in 10% of claims with a mean payment amount of $7669. Mean patient age was 55.6 years. Within severity of injuries, 65% of claims were classified as "Permanent Minor." The most common contributing factor in claims was "Technical Knowledge/Performance" and the most common plaintiff allegation was "Trauma from endotracheal tube placement." Bilateral vocal cord paralysis, unilateral (left-sided) vocal cord paralysis, and laryngeal nerve injury were the top alleged complications. The surgical specialty in which claims most often resulted was orthopedic surgery.

CONCLUSIONS

Injuries related to endotracheal intubation remain an ongoing challenge to anesthesiologists. Their etiology is often multifactorial and was found in this study to stem most commonly from technical errors and patient co-morbidities. A detailed discussion of risks with patients during the consent process, careful documentation of such discussion, and prompt referral to specialists when needed are critical. Understanding the patterns related to injuries during intubation is essential in order to develop strategies for improved patient safety and outcomes.

Efficacy of Conversation Training Therapy for Patients With Benign Vocal Fold Lesions and Muscle Tension Dysphonia Compared to Historical Matched Control Patients

Purpose Conversation training therapy (CTT) is the 1st voice therapy approach to eliminate the traditional therapeutic hierarchy and use patient-driven conversation as the sole therapeutic stimulus. The purpose of this investigation was to determine the efficacy of CTT compared to standard-of-care voice therapy approaches for the treatment of patients with voice disorders. Method A prospective study of CTT treatment outcomes in adults with dysphonia due to primary muscle tension dysphonia or benign vocal fold lesions compared to age, gender, and diagnosis historical matched control (HMC) patients was used. The primary outcome was change in Voice Handicap Index-10 (VHI-10); secondary outcomes included acoustic, aerodynamic, and auditory-perceptual outcomes. Data were collected before treatment (baseline), at the start of each therapy session, 1 week after the final therapy session (short-term follow-up), and 3 months after the final therapy session (long-term follow-up). Results For the CTT group, statistically significant improvements were observed for VHI-10. Though statistically significant improvements were observed for the VHI-10 for the HMC group, the CTT group saw significantly greater improvement in VHI-10. Furthermore, equivalent gains were observed following only 2 sessions of CTT compared to 4-8 sessions of traditional therapy. Significant improvements in the CTT group were observed for cepstral peak prominence in a vowel, fundamental frequency, Cepstral Spectral Index of Dysphonia in a vowel and connected speech, vocal intensity, average airflow in speech in a reading passage, number of breaths and duration of reading passage, and auditory-perceptual measurement of overall voice severity. Conclusions Results support the hypothesis that training voice techniques in the context of spontaneous conversational speech improves patient perception of voice handicap and acoustic, aerodynamic, and auditory-perceptual voice outcomes both immediately following treatment and at long-term follow-up. CTT participants also demonstrated significantly larger decreases in VHI-10 compared to HMC participants who received standard-of-care, nonconversational, hierarchical-based voice therapy.

Diagnostic Value of Acoustic and Aerodynamic Measurements in Vocal Fold Movement Disorders and their Correlation with Laryngeal Electromyography and Voice Handicap Index

OBJECTIVES

Investigate the relationships between the Voice Handicap Index, laryngeal electromyography, and objective acoustic voice testing in order to determine the utility of these measures in the management of vocal fold movement disorders.

METHODS

A retrospective review of patients who had completed a Voice Handicap Index-10 (VHI-10) questionnaire, laryngeal electromyography (LEMG), and objective acoustic measurements (including jitter, relative average perturbation, shimmer, noise-to-harmonic ratio, and standard deviation of fundamental frequency). All three tests had been completed within 30 days of the initial evaluation. All patients' results for acoustic measures were recorded as standard deviations from the norm. LEMG results were converted to grade of paresis (mild, moderate, severe) based on the muscle with the lowest recruitment. Spearman correlation coefficients were calculated to determine the relationship between these three parameters.

RESULTS

A total of 313 subjects were included in the analysis. VHI-10, LEMG (grade of paresis), and objective acoustic measures were, at best, weakly correlated. VHI-10 was better correlated than LEMG to each acoustic parameter including the average acoustic scores; however, the highest correlation observed only reached ρ = 0.349 (P < 0.001). The acoustic variables that correlated best with VHI-10 and LEMG were the standard deviation of the fundamental frequency (ρ = 0.349, P < 0.001) and shimmer (ρ = 0.207, P < 0.001), respectively.

CONCLUSION

This study demonstrates that these measures are, at best, weakly associated. VHI-10 correlated better than LEMG (grade of paresis) to each acoustic voice analysis parameter. However, the maximum correlation coefficient observed was 0.349. Therefore, VHI-10 scores and objective voice acoustic measurements are not useful for predicting the severity of vocal fold movement disorders. Moreover, a given severity of paresis can have different effects on voice handicap and acoustic output in different individuals.

Laryngeal Solitary Fibrous Tumor: A Case Report and Systematic Review

OBJECTIVES/HYPOTHESIS

Solitary fibrous tumors are spindle cell neoplasms of mesenchymal origin that rarely occur in the larynx and may be mistaken for other pathologies. This case presentation and systematic review investigates presentation, treatment modalities, and outcomes of this unusual tumor.

STUDY DESIGN

Systematic review of PubMed, CINAHL, Web of Science, and EMBASE including a novel case presentation METHODS: A systematic search according to the PRISMA guidelines was performed to isolate the reports of solitary fibrous tumors arising in the larynx and its subsites. Variables analyzed included patient demographics, presenting symptoms, smoking status, concurrent tumors, imaging studies, biopsy results, treatment, outcomes, and follow-up. Our additional report provides the second such description of this lesion originating within the true vocal fold.

RESULTS

Systematic review revealed 21 previous reports of solitary fibrous tumors originating from laryngeal subsites. The most common presenting symptom was dysphonia. All patients underwent local excision. Two patients had recurrences. Our patient presented with progressive dysphonia over 4 years. Stroboscopic examination revealed a large translucent mass of the left vocal fold. Local excision of the tumor was achieved with transoral resection with KTP laser. Immunohistochemical staining demonstrated a strong positivity for CD34 and HMW CK34BE12. Nine-month follow-up has not revealed any evidence of persistent or recurrent disease.

CONCLUSION

Laryngeal solitary fibrous tumors are rare and are unlikely to recur in the absence of malignant findings. Complete surgical resection is an acceptable treatment for this lesion accompanied by appropriate follow-up.

Dehydration and Estrous Staging in the Rat Larynx: an in vivo Prospective Investigation

OBJECTIVE

This novel study sought to untangle the association between hydration state and the estrous cycle in the vocal folds, since the voice is reported to negatively change in speakers during the estrous cycle and with dehydration. We hypothesized that there would be alterations in vocal fold tissue morphology depending on hydration state and that these changes would vary with the estrous cycle.

STUDY DESIGN

Prospective, in vivo study design.

METHODS

Female Sprague Dawley rats (n = 30) were used in this study. Sixteen rats were systemically dehydrated to an average of 10% reduction in body weight by withholding water (range of body weight loss: 8%-13%). Fourteen rats were assigned to euhydrated, control condition. Estrous stage of female Sprague Dawley rats (n = 30) was determined via cytological evaluation of vaginal smears. Following euthanization, larynges were prepared for histological staining with hematoxylin and eosin, Masson's trichrome and alcian blue (pH 2.5). To quantify hyaluronan, alcian blue staining was completed pre- and posthyaluronidase incubation. The change in staining percent was quantified with image analysis algorithms and reported as the hyaluronan quantity. Relative collagen distribution (index of dehydration), hyaluronan quantity, and tissue morphology were the outcome measures.

RESULTS

Systemic dehydration was associated with changes in hyaluronan quantity in the rat vocal fold lamina propria. Dehydration did not significantly affect the collagen distribution nor the tissue morphology. Estrous stage alone does not impact the quantity of vocal fold hyaluronan, alter tissue morphology, or change collagen distribution.

CONCLUSION

Decreases in hyaluronan quantity in the lamina propria of the rat vocal fold may play a role in tissue fluid balance during systemic dehydration. Future studies will expand this work to investigate additional components of the vocal fold extracellular matrix to fully elucidate the impact of hydration state on the vocal fold.

[Comparison of intubation using duoscope double blade laryngoscope and standard Macintosh blade laryngoscope in manikin model]

Laryngoscope Duoscope (LD) is a disposable, plastic laryngoscope consisting of two different spoons connected by proximal parts, so that one alternately serves as a handle.

AIM

The aim of study was to compare classical laryngoscope with the one-time Duoscope type.

MATERIALS AND METHODS

The study was carried out on 30 patients of the third year of Medical Emergency, previously trained in instrumental airway clearance. It consisted of intubation of the phantom using a standard metal laryngoscope (MR) and a disposable plastic laryngoscope with a double spoon - Duoscope Laryngoscope (LD). After the intubation, each student completed an anonymous questionnaire regarding the time and effectiveness of intubation and the visibility of vocal folds and the general assessment of both laryngoscopes.

RESULTS

The minimum time needed to perform intubation with MR is 16.02 s, and the maximum is 44.17 s, for LD analogically - 17.92 sec. 52.72 s. Mean MR intubation time was shorter than LD (26.43±6.22 s vs. 32.24±8.51 s, statistical significance level p <0.001). The average difference between the time of MR and LD intubation was 7.12 s. The second analyzed factor was the effectiveness of intubation; significantly higher with MR in relation to LD (90% vs. 43.3% efficiency, statistical significance level p<0.0001). The next analyzed factor was the visibility of vocal folds at laryngoscopy. It was after averaging for MR 84.3%, for LD 23%. The average LD score in the 10-point scale of the subjective assessment of the usability of the laryngoscope for intubation was 3.13 points (standard deviation 1.92, median 3 points).

CONCLUSIONS

The results of the study strongly support the predominance of the classical laryngoscope over the one-time Duoscope type.

Paradoxical Vocal Cord Motion in a Pair of Twin Preterm Infants

BACKGROUND

Intractable obstructive apneas requiring multiple intubations are rare in newborns.

CASE CHARACTERISTICS

We report a pair of twins born at 29 weeks gestation who had severe obstructive apneas due to Paradoxical Vocal Cord Motion (PVCM).

OUTCOME

The symptoms resolved promptly with ipratropium nebulization. Follow-up at 12 months of age revealed normal development.

MESSAGE

PVCM should be considered in the differential diagnosis of intractable obstructive apneas in very low birth weight preterm infants.

[Laryngeal dystonia: novel forms of therapeutic administration of botulinum toxin by direct routes]

AIM

To describe our experience in the treatment of laryngeal dystonia (in abduction and adduction), with special emphasis given to the technical aspects (approach procedure, dosage and type of botulinum toxin type A used), as well as treatment response and possible side effects.

PATIENTS AND METHODS

We conducted a cross-sectional descriptive study of a sample of patients with laryngeal dystonia treated by means of transoral administration of onabotulinumtoxinA or incobotulinumtoxinA over a period of 10 years (2007-2017). Data collected include demographic and clinical variables, treatment response (based on a self-rating scale), the duration of treatment and the appearance of side effects.

SAMPLE SIZE

15 patients (11 women; mean age: 44.06 years) with laryngeal dystonia (mean time since onset of 40 months; 12 patients with dystonia in adduction) and 174 administrations (92% incobotulinumtoxinA; average dosage of 5 U in each vocal cord). The procedure took an average of 11.7 minutes to perform. Response was good in 31% of the procedures and very good in 57.5%. Side effects were recorded in 14.4% of the procedures, although always mild and transitory, with a predominance of dysphagia and dysphonia.

CONCLUSION

In our experience, transoral administration of botulinum toxin type A to treat laryngeal dystonia has proved to be a simple, quick, effective and safe technique.

[Paradoxical vocal fold motion, a real breathing problem : diagnosis and treatment]

The paradoxical vocal fold motion (PVFM) is a temporary total inability to breathe, which is important to rule out from other more or less important breathing difficulties encountered in asthma. Overtreatment for asthma instead of treatment for PVFM can lead to iatrogenic complications which can be averted by early and correct diagnosis. This article presents a list of symptoms and related disorders, enabling to more easily diagnose PVFM, as well as its specifics treatments and a « Block-unblock maneuver » not yet described in the literature, allowing the patient to respond to the crisis and to prevent future crises.

Response to Lieberman on "Monkey vocal tracts are speech-ready"

Macaques do have a speech-ready vocal tract, but lack a speech-ready brain to control it.

Detection of the Vibration Signal from Human Vocal Folds Using a 94-GHz Millimeter-Wave Radar

The detection of the vibration signal from human vocal folds provides essential information for studying human phonation and diagnosing voice disorders. Doppler radar technology has enabled the noncontact measurement of the human-vocal-fold vibration. However, existing systems must be placed in close proximity to the human throat and detailed information may be lost because of the low operating frequency. In this paper, a long-distance detection method, involving the use of a 94-GHz millimeter-wave radar sensor, is proposed for detecting the vibration signals from human vocal folds. An algorithm that combines empirical mode decomposition (EMD) and the auto-correlation function (ACF) method is proposed for detecting the signal. First, the EMD method is employed to suppress the noise of the radar-detected signal. Further, the ratio of the energy and entropy is used to detect voice activity in the radar-detected signal, following which, a short-time ACF is employed to extract the vibration signal of the human vocal folds from the processed signal. For validating the method and assessing the performance of the radar system, a vibration measurement sensor and microphone system are additionally employed for comparison. The experimental results obtained from the spectrograms, the vibration frequency of the vocal folds, and coherence analysis demonstrate that the proposed method can effectively detect the vibration of human vocal folds from a long detection distance.

[Progress in diagnosis and treatment of vocal fold nodules]

Vocal fold nodules is the common cause of the hoarseness,which seriously affected people's living standard.At present,the treatment of the vocal fold nodules should be based on conservative treatment,surgical treatment as a supplement.Conservative treatment mainly includes:rest the voice,drug treatment,intervention and voice therapy.Surgical treatment is mainly the laryngomicrosurgery in suspension laryngoscope. The purpose of this study is to summarize the diagnosis and the treatment of vocal fold nodules,improving the reference of clinical workers.

[IN-OFFICE VOCAL CORD INJECTION FOR TREATMENT OF DYSPHONIA]

INTRODUCTION

Dysphonia significantly damages quality of life and employment opportunities. One of the common causes of hoarseness is glottic insufficiency, namely the lack of full adherence of the vocal cords during speech and swallowing. Correction is achieved by vocal cord medialization.

OBJECTIVES

To examine the effect of vocal cord injection with carboxymethyl cellulose and hydroxyapatite under local anesthesia in the office, on the voice objectively, assessment by staff and patient satisfaction.

METHODS

This prospective and retrospective study included 38 vocal cord injections: 30 involved carboxymethyl cellulose injections, and 8 were injected with hydroxyapatite. Objective and subjective parameters were collected before the injection and 1-2 weeks after the injection.

RESULTS

Average subjective disturbance of the voice decreased from 5.9 to 4.1 post-injection (p<0.01). Average Voice Handicap Index (VHI) decreased from 75.3 to 39.1 (p<0.01) and average Glottic Function Index (GFI) decreased from 15.7 to 9.5 (p<0.01). Average GRABS decreased from 11.9 to 6 (p<0.01) and average visual analogue scale decreased from 4 to 2.5 (p<0.01). Average Maximal Phonation Time increased from 6.9 to 9 sec (p=0.1). Average S/Z ratio decreased from 1.8 to 1.3 (p=0.1). Voice analysis showed average jitter decreased from 2.4% to 0.8% (p<0.01) and average shimmer from 10.9% to 5% (p<0.01).

CONCLUSIONS

Vocal cord injection under local anesthesia in the office is a good and safe method for treating glottic insufficiency. Vocal cord injection with carboxymethyl cellulose and hydroxyapatite improves objective and subjective voice properties.

[Airway Management for Partial Lung Lobectomy in a Patient with Subglottic Stenosis: A Case Report]

We report a case of sub-glottis stenosis encountered during anesthetic induction. A 79 year-old male was scheduled for a right partial lung lobectomy with video assisted thoracic surgery. Significant history includes percutaneous coronary intervention and pacemaker insertion for myocardial infarction, tuberculosis, trache- ostomy and radiation therapy for vocal cord cancer. Difficulty in tracheal intubation was predicted, but chest X-ray and CT scan did not show tracheal steno- sis. General anesthesia was induced smoothly and mask ventilation was easy. The vocal cord was fully exposed by McGRATH® MAC laryngoscope. However, inser- tion of double lumen tube (37 Fr) was impossible because of resistance just under the vocal cords. A membranous subglottic stenosis was found using a flexible bronchoscope. Then we inserted ID 7.0 mm single lumen tube and accomplished differential lung ventilation using a bronchial blocker. Surgery was done smoothly. In spite of recent advances in radiographic imaging, some cases of tracheal stenosis are difficult to diagnose.

The effect of vocal fold vertical stiffness variation on voice production

A parametric study was conducted using the numerical technique that coupled a three-dimensional continuum vocal fold model with a one-dimensional Bernoulli flow model to investigate the effect of vocal fold vertical stiffness variation on voice production. Vertical stiffness gradient was defined as the ratio of the inferior-superior stiffness difference to the mean stiffness and was introduced in the cover layer. The results showed that increasing the vertical stiffness gradient would increase the peak flow rate and sound intensity and decrease the open quotient and threshold pressure. The effect was found to be more prominent at low subglottal pressures. The underlying mechanism might be that the reduced stiffness at the superior aspect of the vocal fold would allow a larger lateral displacement and result in a larger vibration. Increasing the vertical stiffness gradient was also found to increase the vertical phase difference and glottal divergent angle during the vocal fold vibration. Meanwhile, increasing the vertical stiffness variation only slightly increased the mean flow rate, which is important to maintaining the speech time between breaths.

Synthetic multi-line kymographic analysis: A spatiotemporal data reduction technique for high-speed videoendoscopy

High-speed videoendoscopy (HSV) enables observation of the true vibratory behavior of the vocal folds. To quantify the vocal fold vibration captured by the HSV, lateral movement features (e.g., glottal width and vocal fold edge displacements) have been extracted as functions of time. The most common analysis method is to extract the features on a lateral strip used to form digital kymogram. The weakness of this method is that it can only capture the vibrational behavior local to the strip location. While the multi-line kymographic approach has been utilized to capture the spatial diversity, the observation points are either fixed or manually positioned. Behaviors of pathological vocal folds, especially those with lesions, are expected to be spatially diverse and also diverse among speakers, making fixed observation points ineffective. This paper proposes a technique to synthesize kymographic waveforms from full spatiotemporal HSV feature data to extract distinctive behaviors automatically. Each synthesized waveform represents a non-overlapping section of the glottis, where vocal folds are locally behaving homogeneously. The efficacy of the algorithm is demonstrated with four HSV recordings (three pathological) and discussed, including mitigation of the known drawbacks.

Mechanics of human voice production and control

As the primary means of communication, voice plays an important role in daily life. Voice also conveys personal information such as social status, personal traits, and the emotional state of the speaker. Mechanically, voice production involves complex fluid-structure interaction within the glottis and its control by laryngeal muscle activation. An important goal of voice research is to establish a causal theory linking voice physiology and biomechanics to how speakers use and control voice to communicate meaning and personal information. Establishing such a causal theory has important implications for clinical voice management, voice training, and many speech technology applications. This paper provides a review of voice physiology and biomechanics, the physics of vocal fold vibration and sound production, and laryngeal muscular control of the fundamental frequency of voice, vocal intensity, and voice quality. Current efforts to develop mechanical and computational models of voice production are also critically reviewed. Finally, issues and future challenges in developing a causal theory of voice production and perception are discussed.

Influence of vocal tract geometry simplifications on the numerical simulation of vowel sounds

For many years, the vocal tract shape has been approximated by one-dimensional (1D) area functions to study the production of voice. More recently, 3D approaches allow one to deal with the complex 3D vocal tract, although area-based 3D geometries of circular cross-section are still in use. However, little is known about the influence of performing such a simplification, and some alternatives may exist between these two extreme options. To this aim, several vocal tract geometry simplifications for vowels [ɑ], [i], and [u] are investigated in this work. Six cases are considered, consisting of realistic, elliptical, and circular cross-sections interpolated through a bent or straight midline. For frequencies below 4-5 kHz, the influence of bending and cross-sectional shape has been found weak, while above these values simplified bent vocal tracts with realistic cross-sections are necessary to correctly emulate higher-order mode propagation. To perform this study, the finite element method (FEM) has been used. FEM results have also been compared to a 3D multimodal method and to a classical 1D frequency domain model.

Laryngeal muscular control of vocal fold posturing: Numerical modeling and experimental validation

A three-dimensional continuum model of vocal fold posturing was developed to investigate laryngeal muscular control of vocal fold geometry, stiffness, and tension, which are difficult to measure in live humans or in vivo models. This model was able to qualitatively reproduce in vivo experimental observations of laryngeal control of vocal fold posturing, despite the many simplifications which are necessary due to the lack of accurate data of laryngeal geometry and material properties. The results present a first comprehensive study of the co-variations between glottal width, vocal fold length, stiffness, tension at different conditions of individual, and combined laryngeal muscle activation.

3D Reconstruction of Human Laryngeal Dynamics Based on Endoscopic High-Speed Recordings

Standard laryngoscopic imaging techniques provide only limited two-dimensional insights into the vocal fold vibrations not taking the vertical component into account. However, previous experiments have shown a significant vertical component in the vibration of the vocal folds. We present a 3D reconstruction of the entire superior vocal fold surface from 2D high-speed videoendoscopy via stereo triangulation. In a typical camera-laser set-up the structured laser light pattern is projected on the vocal folds and captured at 4000 fps. The measuring device is suitable for in vivo application since the external dimensions of the miniaturized set-up barely exceed the size of a standard rigid laryngoscope. We provide a conservative estimate on the resulting resolution based on the hardware components and point out the possibilities and limitations of the miniaturized camera-laser set-up. In addition to the 3D vocal fold surface, we extended previous approaches with a G2-continuous model of the vocal fold edge. The clinical applicability was successfully established by the reconstruction of visual data acquired from 2D in vivo high-speed recordings of a female and a male subject. We present extracted dynamic parameters like maximum amplitude and velocity in the vertical direction. The additional vertical component reveals deeper insights into the vibratory dynamics of the vocal folds by means of a non-invasive method. The successful miniaturization allows for in vivo application giving access to the most realistic model available and hence enables a comprehensive understanding of the human phonation process.

Receiver Operating Characteristic Analysis of Aerodynamic Parameters Obtained by Airflow Interruption: A Preliminary Report

Aerodynamic parameters provide objective and quantitative measures of laryngeal functional status. Jiang et al previously introduced an airflow interruption technique that can determine mean phonatory airflow, subglottic pressure, and phonation threshold pressure simultaneously and noninvasively. In this study, we performed receiver operating characteristic (ROC) analysis to evaluate this airflow interruption apparatus for voice profile analysis in subjects with laryngeal polyps or nodules or with Parkinson's disease. Patients with polyps (n = 14), nodules (n = 9), and Parkinson's disease (n = 12) were evaluated with the airflow interruption apparatus. Normal subjects served as controls. Mean airflow, subglottic pressure, and phonation threshold pressure were determined. Discriminant analysis was used to create linear equations combining all three parameters in order to obtain a new combined parameter. Solutions to the linear equations yielded values for the combined parameter that took into account mean airflow, subglottic pressure, and phonation threshold pressure. Combined parameter values were used as data to generate ROC curves. Laryngeal polyps were distinguished from the normal larynx with a sensitivity of 0.929 and a specificity of 0.933 at the point of maximal efficiency. The area under the ROC curve was 0.977 (Az). Patients with Parkinson's disease were distinguished from normal subjects with a sensitivity of 0.667 and a specificity of 0.909 at the point of maximal efficiency. The area under the ROC curve was 0.7958 (Az). Nodules were able to be distinguished from normal with a sensitivity of 0.889 and a specificity of 1.00. The area under the ROC curve was 0.9565 (Az). Our conclusions are twofold. First, aerodynamic parameters may be combined for simultaneous consideration by the construction of linear equations by means of discriminant analysis. Second, the airflow interruption apparatus, when used for voice function evaluation, has high sensitivity and specificity.

Airway Resistance and Airflow Dynamics after Fat Injection into Vocal Folds

Objectives:

The aim of this prospective study was to verify whether vocal fold fat augmentation (VFFA) modifies upper airway patency. To the best of our knowledge, this is the first study analyzing the impact of VFFA on laryngeal resistance to airflow.

Methods:

Twenty-one consecutive patients 16 to 74 years of age underwent 24 VFFA operations because of glottic incompetence due to laryngeal hemiplegia (13 patients) or vocal fold tissue defects (8 patients). Flow-volume loop spirometry and body plethysmography were performed before and 1 to 6 months after surgery.

Results:

There were no significant differences between preoperative and postoperative pulmonary volumes (FVC and FEV1), expiratory flows (PEF, FEF50), or inspiratory flows (PIF, FIF50), although a slight increase in inspiratory flows meant that FEF50/FIF50 slightly decreased. Specific airway resistance (sRaw) increased after VFFA, but not in a statistically significant manner (p = .078). None of the patients experienced postoperative stridor. One obese woman with laryngeal hemiplegia had postoperative effort dyspnea; her respiratory studies showed a reduction in inspiratory flows and an increase in sRaw, and demonstrated progressive improvement.

Conclusions:

Flow-volume loop spirometry showed that VFFA does not significantly modify respiratory airflows, although a slight increase of inspiratory airflows suggested an improvement in variable extrathoracic obstruction. Body plethysmography proved to be a sensitive procedure that highlighted the subtle increase in upper airway resistance. Hence, VFFA can be considered a relatively safe procedure for achieving vocal fold medialization, and spirometry and plethysmography can be useful for preoperative assessment and postoperative follow-up.

Management of Benign Vocal Fold Lesions: A Survey of Current Opinion and Practice

Empirical data are often not available to guide clinical practices in the treatment of benign mucosal lesions of the vocal folds. The purpose of this report is to describe opinions and practices in order to identify areas of consensus and discrepancy and thus guide future inquiry. A 16-item survey mailed to all active US members of the American Academy of Otolaryngology—Head and Neck Surgery (n = 7,321) included questions on the use of voice therapy; diagnostic testing; perioperative use of steroids, antibiotics, and antireflux medications; and use of lasers. Responses used a Likert 5-point scale with end anchors of 1 equaling “never” and 5 equaling “always” and were stratified according to lesion (nodules, polyps, cysts). A 16.5% response rate (n = 1,208) was obtained. A lack of consensus was most evident in the use of voice therapy for lesions other than nodules; antireflux medication; and intravenous steroids. Disagreement was also noted regarding the use of lasers, oral steroids, and antibiotics. Other than voice therapy as initial intervention for nodules, no statistically significant differences by lesion type exist regarding use of voice therapy, laser, or any medication. Prospective clinical trials addressing voice therapy, antireflux medications, steroids, and antibiotics are needed to inform clinical practice. Furthermore, treatment practices appear to be largely independent of lesion type. Therefore, traditional diagnostic categories do not seem to be useful guides to treatment, and may need to be reevaluated in light of improvements in diagnostic technology and surgical technique.

Laryngeal Thrush

Superficial fungal infection of the mucous membranes (thrush) isolated to the larynx is neither widely reported nor well recognized clinically. Therefore, it is often associated with ineffective treatment and delay in diagnosis, and sometimes associated with unneeded surgical intervention. Eight cases of thrush isolated to the larynx, with no oral or oropharyngeal manifestations, are presented. Four of these were isolated to the vocal folds alone. All patients were adults, and 4 were smokers. Hoarseness was always present. Pain was present inconsistently, and there was no dysphagia or odynophagia, in contrast to other forms of upper aerodigestive tract candidiasis. On average, diagnosis was not made until 6 months after the onset of symptoms. Possible causative factors included use of systemic steroids (3 cases), broad-spectrum antibiotics (1 case), or inhaled steroids (5 cases); diabetes (2 cases); and neutropenia (1 case). In 3 cases, all with thrush isolated to the vocal folds, inhaled steroids were the only causative factor identifiable — a feature reported only twice previously. Three patients underwent surgical procedures that might have been avoided had an accurate diagnosis been made. All patients responded readily to oral fluconazole and removal of predisposing factors where possible. The signs, symptoms, predisposing factors, and treatment are compared to those of 14 cases reported in the literature over 35 years.

Hands-on Training Methods for Vocal Fold Injection Education

Objectives:

Vocal fold injection (VFI) in the office setting and in the operating room is becoming increasingly popular. Most training programs fail to educate residents in performing these injections. In this report, we describe novel and effective teaching tools that provide real-life simulation of VFI for the education of residents and otolaryngologists in practice.

Methods:

Equipment was developed to allow the use of excised fresh cadaver larynges to simulate peroral VFI in a life-sized model of the human head and neck. A separate setup was also developed for use of a laryngoscope holder and cadaver larynges to simulate microlaryngoscopy VFI. Each of these VFI training setups allows the student to perform and practice VFI in a simulated setting with physical and anatomic constraints and laryngeal anatomy similar to those of real-life VFI. The use of fresh cadaver larynges allows the user to have a realistic feel of actual injection. A visual analog scale was used to measure the participants' comfort levels with the peroral and microlaryngoscopic injection techniques before and after the workshop.

Results:

Pre-workshop and post-workshop surveys were collected from 22 of the VFI course participants. The mean comfort levels for VFI prior to the workshop were 22 for peroral VFI and 69 for microlaryngoscopy VFI (0 = not comfortable at all and 100 = very comfortable). The post-workshop comfort levels were 52 for peroral VFI and 85 for microlaryngoscopy VFI. The differences in the pre- and post-workshop comfort level scores for each VFI technique were significant (microlaryngoscopy, p = .001; peroral, p <0001).

Conclusions:

The use of VFI simulations appears to improve surgeon comfort level with injection techniques. The described training simulations may be useful for allowing residents and practicing otolaryngologists to learn VFI before attempting these techniques on actual patients.