Effects of Superomedial Partial Arytenoidectomy on Incomplete Posterior Glottal Closure Caused by Arytenoid Positional Asymmetry in Excised Human Larynges.

OBJECTIVES: To analyze the effects that arytenoid positional asymmetry has on posterior glottic closure and to determine whether superomedial partial arytenoidectomy (SPA) can provide a benefit in cases of such asymmetry. METHODS: In this experimental study, we evaluated posterior glottic closure in 10 larynges freshly excised from human cadavers, measuring the distance between the vocal processes before and after artificially simulated positional asymmetry of the arytenoid cartilages. We then performed SPA, after which we again measured the distance between the vocal processes. RESULTS: In all of the larynges studied, the posterior glottic closure went from complete to incomplete after simulation of arytenoid positional asymmetry, the median distance observed between the vocal processes being 1.74mm (interquartile range 0.22). The SPA performed after arytenoid asymmetry caused the posterior glottic closure to return from incomplete to complete in all of the larynges studied. CONCLUSION: Our results suggest that arytenoid positional asymmetry impairs posterior glottic closure and that SPA improves posterior glottic closure in such cases of arytenoid asymmetry.

Bipedicled Vocal Fold Mucosal Flap: An Experimental Study.

OBJECTIVE: To determine the dimensions of mucosal defects that can be covered by a bipedicled vocal fold mucosal flap. METHODS: We used 20 adults human larynges (10 of each gender) excised from cadavers, divided into 2 groups of 10 larynges (5 of each gender) each. In one group (the normal flap group), we created the largest possible bipedicled vocal fold mucosal flap and then quantified the dimensions of the largest defect that could be covered by displacing the flap medially. In the other group (the augmented flap group), the flap was augmented laterally with mucosa from the laryngeal ventricle and we determined whether the larger flap would effectively cover larger defects. RESULTS: The mean width of mucosal defect capable of being covered was 1.51 mm when the normal bipedicled flap was employed and was 1.67 mm when the augmented flap was applied. However, the difference was not statistically significant. We found that defect size correlated with vocal fold length, width and flap size in the normal flap group, whereas it correlated only with vocal fold length in the augmented flap group. The bipedicled flap is capable of covering larger defects in males. CONCLUSION: Enlargement of a bipedicled vocal fold mucosal flap with laryngeal ventricular mucosa does not necessarily translate to an increase in the size of defect that can be covered. On average, the flap should be 30% larger than the width of the defect. The statistical model for predicting the defect size based on the vocal fold length, vocal fold width, and flap size has excellent predictive quality when a normal flap is employed.

Excised human larynx in N-vinyl-2-pyrrolidone-embalmed cadavers can produce voiced sound by pliable vocal fold vibration.

Tissue-hardening effect and health-hazard issue of formaldehyde (FA) have long been a great disadvantage of this conventional fixative in anatomical research. We recently developed a FA-free embalming method for cadavers which utilizes N-vinyl-2-pyrrolidone (NVP) and enables assessment of motion kinetics by maintaining the softness of embalmed tissue. By assessing the feasibility of NVP-embalmed tissue to mimic vocalization, this study aimed to prove the potential of embalmed cadavers, which have previously been used only for the understanding of anatomical morphology, for the assessment of precise motion physiology in the human body. Ten cadavers embalmed in NVP (n = 6) and FA (n = 4) were incorporated in this study. Excised larynges underwent experimental phonation to mimic vocalization with fast and pliable vibration of vocal folds. High-speed digital imaging was utilized for the assessment of vocal fold vibration. Furthermore, acoustic analysis of the voiced sound, and reproducibility examination were also performed. Regular vocal fold vibrations successfully produced voiced sounds during experimental phonation using NVP-embalmed larynges. The vibratory frequency, vibration amplitude, and stretch rate of the vocal folds were comparable to those of living humans. Six months after the first experiment, the vocal parameters were reproduced, to suggest the long-term preservation potential of our NVP-embalming technique. On the other hand, neither voiced sound nor vocal fold vibration were observed in FA-embalmed larynges. This novel embalming technique could pioneer the next era to utilize embalmed cadavers for the examination of motion physiology in the human body.

Effect of fibrin glue on collagen deposition after autologous fascia grafting in rabbit vocal folds.

OBJECTIVES: Fibrin glue (FG) is a reaction product of fibrinogen and thrombin that forms a fibrin clot responsible for tissue adhesion. However, FG and its components may interfere with wound healing by interacting with cytokines such as transforming growth factor-beta (TGF-beta). The objective of this study was to investigate the effect of FG on collagen deposition after fascia grafting in the vocal folds of rabbits. METHODS: Eighteen rabbits underwent autologous fascia grafting in both vocal folds, and the left side was fixed with FG. Each animal was painlessly sacrificed after 7, 30, or 90 days. The larynx was removed, and the vocal folds were prepared for histomorphometric analysis by picrosirius red staining to evaluate collagen deposition around the graft. RESULTS: There was a significant increase in collagen density around the grafts at 90 days in the vocal folds that were fixed with FG (p=0.0102) compared with the control vocal folds. CONCLUSIONS: Application of FG altered collagen deposition around the fascia grafts, leading to significantly increased collagen density after 90 days. Differences found in the composition of the extracellular matrix in later stages of the healing process are a result of changes that occur in the beginning of this process. Therapeutic interventions, such as the use of FG and/or its components, performed in the early stages of wound healing may interfere with the complex interactions of fibroblasts, inflammatory cells, and cytokines (especially TGF-beta), thereby modulating the healing process.

Source and Filter Acoustic Measures of Young, Middle-Aged and Elderly Adults for Application in Vowel Synthesis.

INTRODUCTION: The output sound has important changes throughout life due to anatomical and physiological modifications in the larynx and vocal tract. Understanding the young adult to the elderly speech acoustic characteristics may assist in the synthesis of representative voices of men and women of different age groups. OBJECTIVE: To obtain the fundamental frequency (f0), formant frequencies (F1, F2, F3, F4), and bandwidth (B1, B2, B3, B4) values extracted from the sustained vowel /a/ of young, middle-aged, and elderly adults who are Brazilian Portuguese speakers; to present the application of these parameters in vowel synthesis. STUDY DESIGN: Prospective study. METHODS: The acoustic analysis of tokens of the 162 sustained vowel /a/ produced by vocally healthy adults, men, and women, between 18 and 80 years old, was performed. The adults were divided into three groups: young adults (18 to 44 years old); middle-aged adults (45 to 59 years old) and, elderly adults (60 to 80 years old). The f0, F1, F2, F3, F4, B1, B2, B3, B4 were extracted from the audio signals. Their average values were applied to a source-filter mathematical model to perform vowel synthesis in each age group both men and woman. RESULTS: Young women had higher f0 than middle-aged and elderly women. Elderly women had lower F1 than middle-aged women. Young women had higher F2 than elderly women. For the men's output sound, the source-filter acoustic measures were statistically equivalent among the age groups. Average values of the f0, F1, F2, F3, F4, B1, and B2 were higher in women. The sound waves distance in signals, the position of formant frequencies and the dimension of the bandwidths visible in spectra of the synthesized sounds represent the average values extracted from the volunteers' emissions for the sustained vowel /a/ in Brazilian Portuguese. CONCLUSION: Sustained vowel /a/ produced by women presented different values of f0,F1 and F2 between age groups, which was not observed for men. In addition to the f0 and the formant frequencies, the bandwidths were also different between women and men. The synthetic vowels available represent the acoustic changes found for each sex as a function of age.

Bipedicled Vocal Fold Mucosal Flap Use in Phonomicrosurgery: Case Series.

OBJECTIVES: The objective of this study was to present a novel surgical technique involving the use of a "bipedicled vocal fold mucosal flap" to repair a mucosal defect and to evaluate the outcomes of patients in whom it was used. MATERIAL AND METHODS: This was a retrospective study of 6 clinical cases. All patients underwent surgery between November 2000 and July 2018, and all procedures were performed by the same surgeon. For the auditory-perceptual assessment, the Grade-Roughness-Breathiness-Asthenia-Strain hoarseness scale was used. We based the stroboscopic evaluation on the European Laryngological Society protocol, analyzing the parameters glottal closure, mucosal wave, and phase symmetry. RESULTS: Ages at the time of surgery ranged from 10 to 52 years, and all of the patients were male. Preexisting vocal fold lesions included polyps, cysts, a sulcus, and mucosal bridges. Among the stroboscopic parameters, only the mucosal wave differed significantly between the preoperative and postoperative periods (P = 0.046). There were also significant postoperative improvements in the overall grade of dysphonia (P = 0.025) and in the degree of breathiness (P = 0.025). CONCLUSIONS: The use of a bipedicled vocal fold mucosal flap appears to promote significant improvements in the mucosal wave and in voice quality. In the patients evaluated here, the technique was used without preoperative planning. However, it proved to be a safe and appropriate means of repairing mucosal defects in the vocal folds, with the potential to preserve rheological properties and promote healing with less chance of fibrosis.

Histologic study of perifascial areolar tissue implanted in rabbit vocal folds: an experimental study.

OBJECTIVES: Perifascial areolar tissue (PAT) consists of loose areolar tissue with viscoelastic properties that are similar to those found in tissues in the superficial layer of the vocal fold. The aim of this study was to quantify the inflammatory process and the collagen content of the graft, as well as that of the host tissue, after placement of a strip of PAT into the rabbit vocal fold. METHODS: Surgeries were performed on 30 rabbits. The grafts were implanted in pockets that were surgically created in the right vocal fold. The left vocal fold (control group) was subjected only to surgical manipulation. The animals were divided into 3 groups for evaluations at 15 days, 3 months, and 6 months, and their larynx tissues were subsequently reviewed by histology. RESULTS: The grafts were characterized by disorganized and thick collagen bundles and were identified in all study groups. The collagen density stayed constant over time. There was an acute inflammatory response induced by the graft at 15 days that did not exist in the specimens taken at 3 and 6 months. Deposition of collagen fibers in the lamina propria was observed starting at 15 days after the operation and was more intense in the experimental vocal fold than in the control vocal fold. CONCLUSIONS: Our findings indicated that PAT has a low tendency for promoting an inflammatory response. However, there was a loss of the original architecture of the graft tissue and a greater deposition of collagen in the implanted vocal folds than in the control group.

Elastic fibers in Reinke's edema.

OBJECTIVES: We describe the distribution of elastic system fibers in the superficial layer of the lamina propria of Reinke's edema, as compared with normal vocal folds. METHODS: Weigert's resorcin-fuchsin stain after oxidation with 10% oxone was used to study the arrangement of elastic fibers. The findings were categorized and afterward compared with the severity of Reinke's edema. RESULTS: Analysis of 20 specimens of vocal folds with Reinke's edema showed that the network of thin elastic fibers in Reinke's space lost their undulated appearance and had a tangled aspect. In addition, these fibers were no longer parallel to the epithelial basement membrane, but had a random distribution scattered throughout Reinke's space. The elastic fiber network immediately below the epithelial basement membrane also appeared more fragmented in Reinke's edema because of some alteration in organization combined with the 5-microm-thick histologic sectioning plane. No significant difference in the degree of elastic system fiber disarrangement was observed between severity grades II and III (p = 0.382). Large areas of disarrangement were predominant (80% of cases). CONCLUSIONS: The disarrangement of elastic fibers in Reinke's edema may cause insufficient tissue resistance and resilience, contributing to the hypermobility observed in Reinke's edema.

Histologic study of acute vocal fold wound healing after corticosteroid injection in a rabbit model.

OBJECTIVES: Injectable corticosteroids have been used in phonosurgery to prevent scarring of the vocal fold because of their effects on wound healing, and to ensure better voice quality. We histologically evaluated the effects of dexamethasone sodium phosphate infiltration on acute vocal fold wound healing in rabbits 3 and 7 days after surgically induced injury by quantification of the inflammatory reaction and collagen deposition. METHODS: A standardized surgical incision was made in the vocal folds of 12 rabbits, and 0.1 mL dexamethasone sodium phosphate (4 mg/mL) was injected into the left vocal fold. The right vocal fold was not injected and served as the control. The larynges were collected 3 and 7 days after surgery. For histologic analysis, the vocal folds were stained with hematoxylin-eosin for quantification of the inflammatory response and with picrosirius red for quantification of collagen deposition. RESULTS: There was no quantitative difference in the inflammatory response between vocal folds injected with the corticosteroid and control vocal folds. However, the rate of collagen deposition was significantly lower in the corticosteroid-treated group at 3 and 7 days after injury (p = 0.002). CONCLUSIONS: The present results suggest that dexamethasone reduces collagen deposition during acute vocal fold wound healing.

Measurement of the viscoelastic properties of the vocal folds.

OBJECTIVES: Studies of the viscoelastic properties of the vocal folds are normally performed with rheometers that use parallel plates whose interplate space is usually arbitrarily assigned a fixed value. In tissues subject to variation of thickness between samples, fixed gaps could result in different compressions, compromising the comparison among them. We performed an experimental study to determine whether different compressions can lead to different results in measurements of dynamic viscosity (DV) of vocal fold samples. METHODS: We measured the DV of vocal fold samples of 10 larynges of cadavers under 3 different compression levels, corresponding to 0.2, 0.5, and 10 N on an 8-mm-diameter parallel-plate rheometer. RESULTS: The DV directly varied with compression. We observed statistically significant differences between the results of 0.2 and 10 N (p = 0.0396) and 0.5 and 10 N (p = 0.0442). CONCLUSIONS: The study demonstrated that the level of compression influences the DV measure and suggests that a defined compression level should be used in rheometric studies of biological tissues.

Fundamental Frequency in Excised Human Larynges after Anterior Glottic Web Formation of Various Extents.

OBJECTIVE: To determine the effect of vocal fold anterior web formation on fundamental frequency with a cadaveric excised larynx model. STUDY DESIGN: Experimental study with excised human larynges. SETTING: Academic tertiary care hospital. SUBJECTS AND METHODS: Sixteen freshly excised human larynges were evaluated with high-speed videoendoscopy and digital kymography during artificially produced vibration. Each larynx was assessed in 4 conditions: preoperative controls and after 25%, 33%, and 50% decreases in the vibratory portion of the vocal folds. The following parameters were evaluated: fundamental frequency, periodicity, vocal fold vibration amplitude, phase symmetry, and glottic closure. RESULTS: The mean fundamental frequencies were 208.87, 250.20, 292.37, and 342.67 Hz for preoperative controls and 25%, 33%, and 50% reductions in vibratory length of the vocal folds, respectively. Fundamental frequency increased with each increase in anterior glottic web extent, and the difference among the groups was statistically significant in absolute values in hertz and in semitone elevation. The mathematical models for estimating postoperative fundamental frequency had a statistically significant coefficient. The vibration of the vocal folds remained periodic in all larynges before and after the procedures. CONCLUSION: There was a significant and progressive increase in the fundamental frequency with each enlargement of anterior glottic web. Based on the control frequency, mathematical models could estimate the value of the fundamental frequency after the procedure.

Variant of the Technique for Laryngeal Microsurgery in Cases of Difficult Laryngoscopy.

Introduction Low exposure of the larynx can make laryngeal microsurgery difficult or even impossible. The application of rigid and contact endoscopy enabled oblique and retrograde angled visualization, allowing transoperative staging with greater reach of the anatomical areas. However, there is difficulty or even impossibility of performing the surgical act, due to the incompatibility of the angled path with the straight surgical tools. Objective To demonstrate the efficiency of the variant of the technique for laryngeal microsurgery in cases of difficult laryngoscopy and to analyze the new surgical instruments specific to the endoscopic procedure. Methods This is a cross-sectional retrospective study, based on the analysis of 30 medical records of patients treated surgically at a philanthropic hospital in the state of Sergipe, Brazil, between the years of 2014 and 2015. Results The technical variant used 30- and 70-degree endoscopes that provided complete oblique view of the endolarynx. The association of angled instruments (forceps, suction pumps, retractors and scissors) enabled the execution of the surgical procedures. Conclusion The association of rigid endoscopy with angled instruments promoted full visualization of the surgical lesion and operative resolution.

The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant.

OBJECTIVE: To verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation. HYPOTHESIS: Auditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required. STUDY DESIGN: Prospective and pre-post repeated measures design. METHODS: Twenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program. RESULTS: Statistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters. CONCLUSIONS: The cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.

Steroid injection in chronic inflammatory vocal fold disorders, literature review.

UNLABELLED: Steroids are potent inhibitors of inflammation and wound repair. Local administration of steroids directly into the larynx has been reported in many laryngeal diseases. AIM: The purpose of this study is to review related literature about the use of steroid injection in patients with benign, inflammatory and chronic vocal disease. METHODOLOGY: We performed an electronic survey in Medline database and selected clinical trials regarding steroid use in benign laryngeal diseases. RESULTS: Steroids are indicated in these situations: 1) acute inflammatory diseases, mainly when edema compromises the airways; 2) auto- immune disease with laryngeal involvement; 3) laryngeal stenosis; 4) benign lesions of the vocal folds, e.g., nodules, polyps and Reinke's edema, to reduce the inflammatory reactions before phonosurgery or in an attempt to avoid surgery; 5) In phonosurgery, aiming to reduce scarring. In this case, it could be used as a preventive measure in vocal fold scarring, or for scar treatment. CONCLUSION: Steroids may be considered an important therapeutic option in the management of many diseases, specially the inflammatory ones, associated with vocal changes.

Upper displacement of the anterior commissure: experimental study of a new phonosurgical approach to raising vocal pitch.

OBJECTIVES: The present study assessed the effects of a unique pitch-raising surgical technique designated upper displacement of the anterior commissure (UDAC), comparing the results with those obtained through cricothyroid approximation (CTA). METHODS: Vocal fold vibration was artificially evoked in 20 excised human larynges through tracheal injection of compressed air. Vocal fold length, fundamental frequency, and videokymography parameters were determined preoperatively, post-CTA, and post-UDAC. In UDAC, a bilateral incision was made between the middle and anterior thirds of the thyroid cartilage. The inferiormost portion of the anterior thyroid cartilage (anterior to the cartilaginous incision) was sutured to the superiormost portion of the posterior thyroid cartilage (posterior to the cartilaginous incision). The anterior commissure was thus moved upward and forward, ensuring increased vocal fold tension. RESULTS: The mean vocal fold length was 16.88 mm preoperatively, 20.02 mm post-CTA, and 18.67 mm post-UDAC (p < .05). The mean fundamental frequency was 151.60 Hz preoperatively, 271.10 Hz post-CTA, and 239.30 Hz post-UDAC (p < .05). The post-CTA and post-UDAC vibration amplitudes were significantly lower than the preoperative values (p < .05). CONCLUSIONS: Vocal fold length and fundamental frequency increased significantly after UDAC (p < .05), although to a lesser degree than after CTA.

Profile of voice professionals seen in a tertiary health center.

UNLABELLED: Work-related laryngopathy may have negative consequences for voice professionals. AIM: To analyze the profile of voice professionals seen in a tertiary level hospital. STUDY DESIGN: a longitudinal historical cohort. METHODS: A retrospective analysis of patient files. Diagnosis was reached using videostroboscopy. RESULTS: 163 patients (119 females and 44 males) were seen. The mean age was 36.5 years. Professionals included spoken voice users (salesman, teachers, telemarketers, receptionists, health professionals) and singers. The most frequent diagnoses were: minor structural changes (33%), nodules (22%), Reinkes edema (10%), and polyps (6%). A correlation was observed between smoking, age and gender; there was an association between smoking and Reinkes edema, leucoplasia and tabagism, females and Reinkes edema, nodules and minor structural changes, and also between patients aged over 40 years and Reinkes edema, and patients under 40 with nodules, laryngitis, and minor structural changes. Symptoms lasted more than 6 months in 74% of patients. CONCLUSION: The profile of voice professionals seen in a tertiary hospital included spoken voice patients and singers. In our study minor structural changes predominated, followed by nodules, Reinke edema and polyps.

Impact of Cricothyroid Muscle Contraction on Vocal Fold Vibration: Experimental Study with High-Speed Videoendoscopy.

OBJECTIVES: The aim of this study was to evaluate the effects of cricothyroid muscle contraction on vocal fold vibration, as evaluated with high-speed videoendoscopy, and to identify one or more aspects of vocal fold vibration that could be used as an irrefutable indicator of unilateral cricothyroid muscle paralysis. STUDY DESIGN: This was an experimental study employing excised human larynges. METHODS: Twenty freshly excised human larynges were evaluated during artificially produced vibration. Each larynx was assessed in three situations: bilateral cricothyroid muscle contraction, unilateral cricothyroid muscle contraction, and no contraction of either cricothyroid muscle. The following parameters were evaluated by high-speed videoendoscopy: fundamental frequency, periodicity, amplitude of vocal fold vibration, and phase symmetry between the vocal folds. RESULTS: Although neither unilateral nor bilateral cricothyroid muscle contraction altered the periodicity of vibration or the occurrence of phase asymmetry, there was a significant decrease in fundamental frequency in parallel with decreasing longitudinal tension. We also found an increase in vibration amplitude of right and left vocal folds, which were similar in terms of their behavior for this parameter in the various situations studied. CONCLUSION: Our results suggest that differences in vibration amplitude and phase symmetry between vocal folds are not reliable indicators of unilateral cricothyroid muscle paralysis.

High-speed Videolaryngoscopy: Quantitative Parameters of Glottal Area Waveforms and High-speed Kymography in Healthy Individuals.

OBJECTIVES: We conducted a study to obtain quantitative parameters of the vocal dynamic using high-speed videolaryngoscopy and to characterize the vocal fold vibration pattern of healthy individuals by analyzing glottal area waveforms and high-speed kymography. METHODS: Laryngeal images of 45 healthy individuals were captured using high-speed videolaryngoscopy. The open and speed quotients of the glottal area waveforms and high-speed kymography were obtained and statistically analyzed according to the gender of each individual. RESULTS: Glottal area waveforms revealed average values of 0.85 and 1.16 for open and speed quotients, respectively, for women, and 0.70 and 1.19 for men. Using high-speed kymography, quantitative parameters of open and speed quotients for women were 0.62 and 1.02, respectively, and for men were 0.57 and 1.12. By gender, a significant statistical difference emerged for open quotients obtained from both glottal area waveforms (P = 0.004) and high-speed kymography (P = 0.013). CONCLUSION: Obtained by using computational tools specifically for analyzing laryngeal images from high-speed videolaryngoscopy, quantitative parameters of glottal area waveforms and high-speed kymography in healthy individuals provide reference data and normality for future studies.

Impact in vocal quality in partial myectomy and neurectomy endoscopic of thyroarytenoid muscle in patients with adductor spasmodic dysphonia.

UNLABELLED: Impact in vocal quality in partial myectomy and neurectomy endoscopic of thyroarytenoid muscle in patients with adductor spasmodic dysphonia the adductor spasmodic dysphonia is a severe vocal disorder characterized by muscle laryngeal spasms during speech, producing phonatory breaks, forced, strained and strangled voice. Its symptoms come from involuntary and intermittent contractions of thyroarytenoid muscle during speech, which causes vocal fold strain, pressed one against another and increased glottic resistance. AIM: report the results in the impact in vocal quality in neurectomy of the thyroarytenoid branch of the inferior laryngeal nerve by endoscopic route associated with partial myectomy of the thyroarytenoid muscle with co2 laser. MATERIAL AND METHODS: the surgery was done in 07 patients (06 females and 01 male), aged 22 to 75, with adductor spasmodic dysphonia. They were submitted to vhi (voice handicap index) before and after surgery. RESULTS AND CONCLUSIONS: the vocal improvement was obtained in all studied patients, deterioration in vocal quality after surgery was not noticed. There was evident difference in the vhi before and after surgery. This surgical technique proved to be efficient and innovative in the treatment of adductor spasmodic dysphonia.