A Method for Reconstruction of Anterior Commissure Glottal Webs With Endoscopic Fibro-Mucosal Flaps

Background:

Anterior-commissure (AC) cicatrization and web formation is a difficult problem that can result from a variety of clinical scenarios. An advancement-rotation flap utilizing papillomatous epithelium and subepithelial fibrous tissue has been previously described. For patients in whom there was not excessive redundant papillomatosis covering the AC web, including other clinical scenarios, a microlaryngoscopic procedure was designed to lengthen the glottal/subglottal aperture using substantial local fibro-mucosal tissue. Although it has been done for over a decade, this approach is not widely known and to our knowledge not photo-documented.

Study Design:

Retrospective.

Material and Methods:

An analysis was done with Institutional Review Board approval that identified 42 patients who underwent 53 procedures to treat AC webs, which were reconstructed with local soft-tissue flaps and without any device/stent to maintain the glottal aperture. The microlaryngoscopic method and technical nuances for this approach with and without diseased epithelium are described and photo-documented. Tactical mucosal incisions were made to facilitate advancement and/or rotation of fibro-mucosal flaps with enough length to resurface the medial aspect of 1 vocal fold. The scarred submucosal soft tissue in the AC region was separated with cold instruments, and the flaps were sutured in position. Variations of this method are demonstrated mobilizing fibro-mucosal soft tissue from different locations, including the web itself, contralateral vocal fold, infrapetiole region, and/or the inner aspect of the thyroid lamina below the anterior-commissure tendon.

Results:

Of the 53 cases in which anterior commissure glottal webs were reconstructed with endoscopic fibro-mucosal flaps, 31 of 53 had recurrent respiratory papillomatosis (RRP). Redundant RRP comprised the majority of the flap in 14 of 31 RRP cases. Fibro-mucosal tissue without a substantial amount of disease occurred in 17 of 31 RRP cases. Of the remaining 22 AC web cases, the primary diagnoses observed were: glottic cancer = 7 of 22, intraepithelial dysplasia = 10 of 22, glottic trauma = 3 of 22, congenital = 1 of 22, and radiotherapy = 1 of 22.

Conclusion:

Endolaryngeal utilization of local fibro-mucosal tissue to lengthen the glottal/subglottal aperture for AC webs is an effective strategy. It can be done without using devices or keels for webs that are congenital or from nonsurgical trauma, idiopathic disease, or postsurgical traumatic cicatrization of the anterior commissure subsequent to treatment of epithelial disease (eg, cancer, dysplasia, and RRP). Normalizing the architecture of the anterior commissure was a valuable asset in patients who require future treatment of epithelial diseases, especially in an office-based setting.

The Art and Craft of Phonomicrosurgery in Grammy Award–Winning Elite Performers

Background:

Since the renowned opera maestro Manuel Garcia presented “Observations on the Human Voice” using mirror laryngoscopy in 1855, there has been an inextricable link between performing vocalists and laryngologists. Today, specialized laryngeal surgeons continue the tradition of integrating medical and surgical management of performers with those skilled in vocal arts, voice science, and voice therapy. With advances in surgical instrumentation and techniques, increasing opportunities have evolved to surgically restore lost performing voices. However, it is especially challenging because of a range of factors, including the need for optimal technical precision, management of expectations, complexity of informed consent, public visibility of these patients, and the economics related to the success and failure of surgery. A number of these key issues apply to phonomicrosurgical procedures in nonsingers as well. Consequently, reviewing the art and craft of phonomicrosurgery in elite performers provides valuable insights into the optimal management of any patient.

Methods:

A retrospective review was done of microlaryngeal procedures for the past 20 years, and 18 elite performers were identified who were Grammy Award winners. Microsurgical methods for different lesions are illustrated. Composite analyses of the group along with their associated pathology was done to provide insights into key issues.

Results:

The 18 patients in this cohort have won 80 Grammy Awards, which were garnered from 242 nominations. All 18 had substantial deterioration in voice quality and could retain more than 1 pathology. Significant loss of superficial lamina propria (SLP) pliability was present in 15 of 18, varices and/or ectasias leading to vocal hemorrhage in 6, vocal polyps in 9, fibrovascular nodules in 6, arytenoid granuloma in 1, sulcus from prior microlaryngeal surgery leading to vocal fold SLP scarring in 4, sulcus from long-term phonotrauma leading to vocal fold SLP scarring in 4, benign cyst in 1, precancerous dysplasia in 2, and invasive carcinoma in 2. Subsequent to phonomicrosurgery, all reported improvement in their performance.

Conclusions:

Laryngologists and laryngeal surgeons have shouldered a burden of responsibility for elite performing vocalists since the origin of our specialty. Most lesions and diagnoses that are encountered result from phonotrauma. Optimizing singers’ care provides surgeons with extremely complex technical, emotional, social, and financial challenges. Focused analysis of managing elite performing vocalists effectively integrates a range of essential issues, which provide key insights to assist clinicians treating nonperforming patients requiring phonomicrosurgery.

Estimating Subglottal Pressure From Neck-Surface Acceleration During Normal Voice Production

Purpose

The purpose of this study was to evaluate the potential for estimating subglottal air pressure using a neck-surface accelerometer and to compare the accuracy of predicting subglottal air pressure relative to predicting acoustic sound pressure level (SPL).

Method

Indirect estimates of subglottal pressure (Psg') were obtained from 10 vocally healthy speakers during loud-to-soft repetitions of 3 different /p/-vowel gestures (/pa/, /pi/, /pu/) at 3 pitch levels in the modal register. Intraoral air pressure, neck-surface acceleration, and radiated acoustic pressure were recorded, and the root-mean-square amplitude of the acceleration signal was correlated with Psg' and SPL.

Results

The coefficient of determination between accelerometer level and Psg' was high when data were pooled from all vowel and pitch contexts for each participant (r2 = .68-.93). These relationships were stronger than corresponding relationships between accelerometer level and SPL (r2 = .46-.81). The average 95% prediction interval for estimating Psg' using accelerometer level was ±2.53 cm H2O, ranging from ±1.70 to ±3.74 cm H2O across participants.

Conclusions

Accelerometer signal amplitude correlated more strongly with Psg' than with SPL. Future work is warranted to investigate the robustness of the relationship in nonmodal voice qualities, individuals with voice disorders, and accelerometer-based ambulatory monitoring of subglottal pressure.

Three-Dimensional Optical Reconstruction of Vocal Fold Kinematics Using High-Speed Video With a Laser Projection System

Vocal fold kinematics and its interaction with aerodynamic characteristics play a primary role in acoustic sound production of the human voice. Investigating the temporal details of these kinematics using high-speed videoendoscopic imaging techniques has proven challenging in part due to the limitations of quantifying complex vocal fold vibratory behavior using only two spatial dimensions. Thus, we propose an optical method of reconstructing the superior vocal fold surface in three spatial dimensions using a high-speed video camera and laser projection system. Using stereo-triangulation principles, we extend the camera-laser projector method and present an efficient image processing workflow to generate the three-dimensional vocal fold surfaces during phonation captured at 4000 frames per second. Initial results are provided for airflow-driven vibration of an ex vivo vocal fold model in which at least 75% of visible laser points contributed to the reconstructed surface. The method captures the vertical motion of the vocal folds at a high accuracy to allow for the computation of three-dimensional mucosal wave features such as vibratory amplitude, velocity, and asymmetry.

Tripling the maximum imaging depth with third-harmonic generation microscopy

The growing interest in performing high-resolution, deep-tissue imaging has galvanized the use of longer excitation wavelengths and three-photon-based techniques in nonlinear imaging modalities. This study presents a threefold improvement in maximum imaging depth of ex vivo porcine vocal folds using third-harmonic generation (THG) microscopy at 1552-nm excitation wavelength compared to two-photon microscopy (TPM) at 776-nm excitation wavelength. The experimental, analytical, and Monte Carlo simulation results reveal that THG improves the maximum imaging depth observed in TPM significantly from 140 to 420 μm in a highly scattered medium, reaching the expected theoretical imaging depth of seven extinction lengths. This value almost doubles the previously reported normalized imaging depths of 3.5 to 4.5 extinction lengths using three-photon-based imaging modalities. Since tissue absorption is substantial at the excitation wavelength of 1552 nm, this study assesses the tissue thermal damage during imaging by obtaining the depth-resolved temperature distribution through a numerical simulation incorporating an experimentally obtained thermal relaxation time (τ). By shuttering the laser for a period of 2τ, the numerical algorithm estimates a maximum temperature increase of ∼2°C at the maximum imaging depth of 420 μm. The paper demonstrates that THG imaging using 1552 nm as an illumination wavelength with effective thermal management proves to be a powerful deep imaging modality for highly scattering and absorbing tissues, such as scarred vocal folds.

Oncologic Efficacy of Angiolytic KTP Laser Treatment of Early Glottic Cancer

Objective:

Angiolytic laser removal of early glottic cancer with ultra-narrow margins was reported in a pilot study 5 years ago as an innovative surgical treatment strategy to better preserve vocal function. Subsequently, in a cohort of > 90 patients, enhanced voice outcomes were achieved and there was diminished need for post-treatment phonosurgical reconstruction. However, the initial pilot study examining oncologic efficacy had a limited number of patients and most did not have 3-year follow-up. Consequently, further analysis of the oncologic efficacy is valuable.

Method:

Retrospective review.

Results:

One hundred seventeen patients (T1a-71, T1b-11, T2a-10, T2b-25) underwent potassium-titanyl-phosphate (KTP) laser treatment of early glottic cancer with a minimum 3-year follow-up (average = 53 months). The “b” designation delineated bilateral disease. Disease control for T1 and T2 lesions was 96% (79/82) and 80% (28/35), respectively. All 10 recurrences were treated with radiotherapy. Fifty percent (5/10) were controlled with radiotherapy, and the other 5 died of disease. Larynx preservation and survival were achieved in 99% (81/82) with T1 disease and 89% (31/35) with T2 disease.

Conclusion:

This investigation provides further evidence that angiolytic KTP laser removal of early glottic cancer with ultra-narrow margins is an effective oncologic treatment strategy. Radiotherapy was preserved for future use in more than 90% of patients. Since a majority of patients are referred by an otolaryngologist to undergo treatment of early glottic cancer with radiotherapy, this investigation provides compelling information to reappraise this paradigm.

Investigating acoustic correlates of human vocal fold vibratory phase asymmetry through modeling and laryngeal high-speed videoendoscopy

Vocal fold vibratory asymmetry is often associated with inefficient sound production through its impact on source spectral tilt. This association is investigated in both a computational voice production model and a group of 47 human subjects. The model provides indirect control over the degree of left-right phase asymmetry within a nonlinear source-filter framework, and high-speed videoendoscopy provides in vivo measures of vocal fold vibratory asymmetry. Source spectral tilt measures are estimated from the inverse-filtered spectrum of the simulated and recorded radiated acoustic pressure. As expected, model simulations indicate that increasing left-right phase asymmetry induces steeper spectral tilt. Subject data, however, reveal that none of the vibratory asymmetry measures correlates with spectral tilt measures. Probing further into physiological correlates of spectral tilt that might be affected by asymmetry, the glottal area waveform is parameterized to obtain measures of the open phase (open/plateau quotient) and closing phase (speed/closing quotient). Subjects' left-right phase asymmetry exhibits low, but statistically significant, correlations with speed quotient (r=0.45) and closing quotient (r=-0.39). Results call for future studies into the effect of asymmetric vocal fold vibration on glottal airflow and the associated impact on voice source spectral properties and vocal efficiency.

Assessment of canine vocal fold function after injection of a new biomaterial designed to treat phonatory mucosal scarring

OBJECTIVES

Most cases of irresolvable hoarseness are due to deficiencies in the pliability and volume of the superficial lamina propria of the phonatory mucosa. By using a US Food and Drug Administration-approved polymer, polyethylene glycol (PEG), we created a novel hydrogel (PEG30) and investigated its effects on multiple vocal fold structural and functional parameters.

METHODS

We injected PEG30 unilaterally into 16 normal canine vocal folds with survival times of 1 to 4 months. High-speed videos of vocal fold vibration, induced by intratracheal airflow, and phonation threshold pressures were recorded at 4 time points per subject. Three-dimensional reconstruction analysis of 11.7 T magnetic resonance images and histologic analysis identified 3 cases wherein PEG30 injections were the most superficial, so as to maximally impact vibratory function. These cases were subjected to in-depth analyses.

RESULTS

High-speed video analysis of the 3 selected cases showed minimal to no reduction in the maximum vibratory amplitudes of vocal folds injected with PEG30 compared to the non-injected, contralateral vocal fold. All PEG30-injected vocal folds displayed mucosal wave activity with low average phonation threshold pressures. No significant inflammation was observed on microlaryngoscopic examination. Magnetic resonance imaging and histologic analyses revealed time-dependent resorption of the PEG30 hydrogel by phagocytosis with minimal tissue reaction or fibrosis.

CONCLUSIONS

The PEG30 hydrogel is a promising biocompatible candidate biomaterial to restore form and function to deficient phonatory mucosa, while not mechanically impeding residual endogenous superficial lamina propria.

[Neurolaryngology]

The neuroanatomy of voice and speech is complex. An intricate neural network is responsible for ensuring the main functions of the larynx: airway protection, cough and Valsalva production, and providing voice. Coordination of these roles is very susceptible to disruption by neurological disorders. Neurological disorders that affect laryngeal function include Parkinson's disease, stroke, amyotrophic lateral sclerosis, multiple sclerosis, dystonia and essential tremor. A thorough neurological evaluation should be routine for any patient presenting with voice complaints suggestive of neurogenic cause. Endoscopic visualisation of the larynx using a dynamic voice assessment with a flexible laryngoscope is a crucial part of the evaluation and ancillary tests are sometimes performed. Otolaryngologic evaluation is important in the diagnosis and treatment of neurological disorders that affect laryngeal function.

Voice production mechanisms following phonosurgical treatment of early glottic cancer

OBJECTIVES

Although near-normal conversational voices can be achieved with the phonosurgical management of early glottic cancer, there are still acoustic and aerodynamic deficits in vocal function that must be better understood to help further optimize phonosurgical interventions. Stroboscopic assessment is inadequate for this purpose.

METHODS

A newly developed color high-speed videoendoscopy (HSV) system that included time-synchronized recordings of the acoustic signal was used to perform a detailed examination of voice production mechanisms in 14 subjects. Digital image processing techniques were used to quantify glottal phonatory function and to delineate relationships between vocal fold vibratory properties and acoustic perturbation measures.

RESULTS

The results for multiple measurements of vibratory asymmetry showed that 31% to 62% of subjects displayed higher-than-normal average values, whereas the mean values for glottal closure duration (open quotient) and periodicity of vibration fell within normal limits. The average HSV-based measures did not correlate significantly with the acoustic perturbation measures, but moderate correlations were exhibited between the acoustic measures and the SDs of the HSV-based parameters.

CONCLUSIONS

The use of simultaneous, time-synchronized HSV and acoustic recordings can provide new insights into postoperative voice production mechanisms that cannot be obtained with stroboscopic assessment.

Photoangiolytic Laser Treatment of Early Glottic Cancer: A New Management Strategy

The 532 nm pulsed KTP (potassium titanyl phosphate) laser and the 585 nm pulsed dye laser (PDL) are photoangiolytic lasers that have been demonstrated to be effective for managing vocal fold dysplasia. The putative mechanism of action is selective photoangiolysis of the sublesional microcirculation. On the basis of this experience, early glottic cancers were treated by selectively targeting the intralesional and sublesional microvasculature. This approach was derived from Folkman's concepts of neoplastic growth resulting from tumor angiogenesis. Staged microlaryngeal treatment was adopted, because it facilitated optimal functional results, and was considered safe, because early glottic cancer rarely metastasizes. Furthermore, intercurrent disease during conventional incremental radiotherapy is typical in treating early glottic cancer. A pilot group of 22 patients with early glottic cancer (13 T1, 9 T2) were treated with a fiber-based angiolytic laser. Eleven of the 22 had unilateral disease and were entirely treated by laser photoangiolysis as a sole modality. Eleven of the 22 had bilateral disease; 5 of the 11 were treated entirely (bilaterally) by laser photoangiolysis, and 6 of the 11 only underwent laser treatment of the less involved vocal fold, with conventional resection being done on the dominant side of the cancer. The initial 8 of the 22 were treated with the PDL, and the latter 14 of the 22 were treated with the pulsed KTP laser. No patient has cancer presently, and none have undergone posttreatment radiotherapy or open surgery. The mean follow-up is 27 months, 13 of the 22 patients have at least 2 years of follow-up, and the first patient was treated just over 5 years ago. Objective measures of vocal function revealed that photoangiolytic treatment of early glottic cancer resulted in significant postoperative improvements despite the fact that half of the patients had bilateral disease. Angiolytic lasers effectively involuted early glottic cancer, with microsurgically directed nonionizing radiation of the dense neoplastic blood supply resulting in complete tumor regression. This approach is conceptually attractive, because it is repeatable, it preserves all conventional cancer treatment options, and it results in excellent vocal function by improving phonatory mucosal wave vibration. Observations from this investigation suggest that this new and novel cancer treatment strategy is effective; however, larger patient cohorts, longer follow-up, and multi-institutional confirmation will be necessary to establish incontrovertible oncological efficacy.

Photoangiolytic Laser Treatment of Early Glottic Cancer: A New Management Strategy

The 532 nm pulsed KTP (potassium titanyl phosphate) laser and the 585 nm pulsed dye laser (PDL) are photoangiolytic lasers that have been demonstrated to be effective for managing vocal fold dysplasia. The putative mechanism of action is selective photoangiolysis of the sublesional microcirculation. On the basis of this experience, early glottic cancers were treated by selectively targeting the intralesional and sublesional microvasculature. This approach was derived from Folkman's concepts of neoplastic growth resulting from tumor angiogenesis. Staged microlaryngeal treatment was adopted, because it facilitated optimal functional results, and was considered safe, because early glottic cancer rarely metastasizes. Furthermore, intercurrent disease during conventional incremental radiotherapy is typical in treating early glottic cancer. A pilot group of 22 patients with early glottic cancer (13 T1, 9 T2) were treated with a fiber-based angiolytic laser. Eleven of the 22 had unilateral disease and were entirely treated by laser photoangiolysis as a sole modality. Eleven of the 22 had bilateral disease; 5 of the 11 were treated entirely (bilaterally) by laser photoangiolysis, and 6 of the 11 only underwent laser treatment of the less involved vocal fold, with conventional resection being done on the dominant side of the cancer. The initial 8 of the 22 were treated with the PDL, and the latter 14 of the 22 were treated with the pulsed KTP laser. No patient has cancer presently, and none have undergone posttreatment radiotherapy or open surgery. The mean follow-up is 27 months, 13 of the 22 patients have at least 2 years of follow-up, and the first patient was treated just over 5 years ago. Objective measures of vocal function revealed that photoangiolytic treatment of early glottic cancer resulted in significant postoperative improvements despite the fact that half of the patients had bilateral disease. Angiolytic lasers effectively involuted early glottic cancer, with microsurgically directed nonionizing radiation of the dense neoplastic blood supply resulting in complete tumor regression. This approach is conceptually attractive, because it is repeatable, it preserves all conventional cancer treatment options, and it results in excellent vocal function by improving phonatory mucosal wave vibration. Observations from this investigation suggest that this new and novel cancer treatment strategy is effective; however, larger patient cohorts, longer follow-up, and multi-institutional confirmation will be necessary to establish incontrovertible oncological efficacy.