Arytenoid appearance and vertical level difference between the paralyzed and innervated vocal cords

Relative Fundamental Frequency: Only for Hyperfunctional Voices? A Pilot Study

(1) Background: Assessing phonatory disorders due to laryngeal biomechanical alterations requires aerodynamic analysis, assessing subglottic pressure, transglottic flow, and laryngeal resistance. This study explores whether the acoustic parameter, the relative fundamental frequency (RFF), can be studied using the current acoustic analysis protocol at the University of Navarra's voice laboratory and its association with pathologies linked to laryngeal biomechanical alterations. (2) Methods: A retrospective cohort study included patients diagnosed with muscular tension dysphonia, organic lesions of the vocal fold, and vocal fold paralysis (VFP) at the Clínica Universidad de Navarra from 2019 to 2021. Each patient underwent endoscopic laryngeal exploration, followed by acoustic study, RFF calculation, and an aerodynamic study. Additionally, a control group was recruited. (3) Results: 79 patients and 22 controls were studied. Two-way ANOVA showed significant effects for groups and cycles in offset and onset cycles. Statistically significant differences were observed in cycle 1 onset among all groups and in cycles 1 and 2 between the control group and non-healthy groups. (4) Conclusions: RFF is a valuable indicator of phonatory biomechanics, distinguishing healthy and pathological voices and different disorders. RFF in onset cycles offers a cost-effective, accurate method for assessing biomechanical disorders without complex aerodynamic analyses. This study describes RFF values in VFP for the first time, revealing differences regardless of aerodynamic patterns.

Dynamic CT Study on the Morphology and the Motor Ability of Unilateral Vocal Fold Paralysis

OBJECTIVE

To investigate the morphological changes and motor functions of the larynx in unilateral vocal fold paralysis by using dynamic three-dimensional CT, and to explore the differences between vocal fold paralysis with different nerves involved.

METHODS

Twenty-five patients with unilateral vocal fold paralysis and 10 healthy subjects were selected as the paralytic group and the normal group, respectively. Ten dynamic sequence images of laryngeal movement from inhalation to phonation were reviewed, and the glottic morphology at the coronal position, the minimum glottic area at the horizontal position, and the overall activity of the two groups were compared. The 25 patients with unilateral vocal fold paralysis were divided into the thyroarytenoid (TA) muscle group, the TA and posterior cricoarytenoid (PCA) (TA + PCA) muscle group, and the PCA muscle group. The coronal and horizontal parameters of the three types were compared as noted above and the dynamic parameter changes were also compared between the groups.

RESULTS

The height and thickness of bilateral vocal cords, the minimum glottic area, and the whole glottic activity were different in the paralysis group and were significantly different from those of the normal group (P < 0.05). The value of the glottic gap ratio and its decrease rate in the TA + PCA group was smaller than those in the TA and PCA group, and the glottic gap ratio was the largest in the PCA group.

CONCLUSION

Dynamic CT can provide a qualitative evaluation of laryngeal morphology and quantitative evaluation of motor function in vocal fold paralysis.

LEVEL OF EVIDENCE: 4

Novel airway-cartilage combined model for medialization laryngoplasty and laryngotracheal reconstruction surgery planning

BACKGROUND

The clinical outcomes of surgical treatments for vocal cord paralysis and tracheal stenosis, such as medialization laryngoplasty and laryngotracheal reconstruction, vary owing to the complex anatomy and physiology of the human upper airway. However, advances in three-dimensional (3D) simulation and printing ushered its use on an office-based workstation to aid in several surgical areas.

METHODS

The preoperation neck computed tomography image was loaded into the InVesalius 3.0 software for manual segmentation of airway and nearby important anatomic landmarks including hyoid bone, thyroid cartilage, and cricoid cartilage. The 3D model of the desired anatomy structure was manufactured and used for presurgical planning and rehearsal of the surgery.

RESULTS

We review cases of four patients: two cases of unilateral vocal palsy undergoing medialization laryngoplasty and two cases of tracheal stenosis patients who used the air-cartilage combined model.

CONCLUSION

Preoperation planning of the medialization thyroplasty could be more precise by prevision of the paralyzed vocal cord plane. Tracheal surgery could benefit from a preoperative design of segmented length. The novel airway-cartilage combined model offers new insight into vocal cord and trachea surgery.

Modified Arytenoid Adduction Operation for the Treatment of Unilateral Vocal Fold Paralysis

INTRODUCTION

Unilateral vocal fold paralysis (UVFP) was a relative common glottic insufficiency disease; however, a completely satisfactory treatment of UVFP was elusive. This study was aimed to evaluate the surgical efficacy of modified arytenoid adduction with fenestration of the thyroid cartilage in the management of patients with UVFP, including voice and aspiration outcomes, and to summarize the postoperative complications.

METHODS

A retrospective analysis was performed on a total of 21 patients who underwent modified arytenoid adduction operation with fenestration of the thyroid cartilage for UVFP from July 2012 to June 2017. The scores of Grade, Roughness, Breathiness, Asthenia, Strain scale (GRBAS), voice self-satisfaction, dynamic laryngoscopy and the voice acoustic data (fundamental frequency [F0], fundamental frequency perturbation [jitter], loudness, amplitude perturbation [shimmer], and maximal phonatory time [MPT], etc.) were statistically analyzed preoperatively and 3-6 months postoperatively. The occurrence of postoperative complications was also summarized.

RESULTS

The voice subjective perception of 21 patients was significantly improved after operation. The rate of voice self-satisfaction was 90.5%. The mean values of voice acoustics parameters were significantly improved. The MPT was significantly longer (p < 0.001), and the ratings of postoperative aspiration were significantly decreased compared with the preoperation. Among the 21 patients, 15 cases had sense of laryngeal obstruction, 8 cases had of 1-2° laryngemphraxis (recovered after 10-15 days). There were 2 cases of laryngeal stridor, 1 case of incision infection, 1 case of pharyngeal fistula, and 1 case of falsetto (corrected by voice training). No patient had laryngeal hematoma, neck hematoma, or laryngospasm.

CONCLUSION

The modified arytenoid adduction operation with fenestration of the thyroid cartilage can significantly improve the vocal function of patients with UVFP and effectively reduce the aspiration, with fewer postoperative complications, less trauma, and more convenient advantages.

A Novel Endoscopic Arytenoid Medialization for Unilateral Vocal Fold Paralysis

OBJECTIVES/HYPOTHESIS

Arytenoid adduction (AA) has been indicated for unilateral vocal fold paralysis (UVFP) patients with vertical vocal fold height mismatch and/or large posterior glottic gaps that are unable to be adequately addressed by anterior medialization techniques. Although AA offers several advantages over other methods, it is technically challenging and involves significant laryngeal manipulation of the cricoarytenoid joint. A novel, minimally invasive endoscopic arytenoid medialization technique is presented for the closure of the posterior commissure.

STUDY DESIGN

Prospective case series.

METHODS

Seventeen consecutive patients were diagnosed and treated with unilateral endoscopic arytenoid medialization (EAM) combined with injection laryngoplasty because of unilateral vocal fold paralysis. Jitter, shimmer, harmonics-to-noise ratio (HNR), maximum phonation time (MPT), fundamental frequency (F₀ ), Voice Handicap Index (VHI), peak inspiratory flow (PIF), and quality of life (QoL) were evaluated preoperatively, 1 month, and 1 year after EAM.

RESULTS

Jitter, shimmer, HNR, and MPT significantly improved and remained stable 1 year after the intervention. F₀ and PIF remained unchanged. Significant improvements in VHI and QoL demonstrated patient satisfaction with voicing and respiratory functions.

CONCLUSIONS

Endoscopic arytenoid medialization is a quick, minimally invasive solution for unilateral vocal fold paralysis. With simultaneous augmentation of the vocal fold, it provides a complete glottic closure along the entire vocal fold in UVFP patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E903-E910, 2021.

Influence of level difference due to vocal folds angular asymmetry on auto-oscillating replicas

Dysphonia is often caused by level difference between left and right vocal folds, which are positioned on different angles with respect to the transverse plane, resulting in angular asymmetry. Unilateral vocal fold paralysis may cause such angular asymmetry. In this case, the normal vocal fold is located on the transverse plane, whereas the paralyzed vocal fold is rotated in the sagittal plane as its posterior edge is moved up to the superior direction. The effect of such angular asymmetry (up to 25°) between the left and right vocal fold on the auto-oscillation is experimentally studied using mechanical replicas. For all replicas, it is observed that, as full contact between vocal folds is lost, increase of angular asymmetry results in a decrease of the signal-to-noise ratio, an increase of the total harmonic distortion rate, and an increase of the oscillation threshold pressure. These general tendencies are in agreement with clinical findings reported for vertical level difference during phonation. In analogy to the preceding experimental study in which vocal folds are spaced in parallel with a vertical trade-off, a formula is proposed to describe the oscillation threshold as a function of angular asymmetry.

Comparison of arytenoid vertical height discrepancy in normal versus patients with vocal cord palsy

OBJECTIVE

Cadaveric experiments and more recently clinical data have demonstrated that patients with vertical height discrepancy between their arytenoids experience poorer voice outcomes in patients with unilateral vocal cord palsy (UVP) after medialisation laryngoplasty. However, the presence or severity of height discrepancy in normal patients without UVP has not yet been clearly defined.

STUDY DESIGN

Case-control study.

SETTING

Tertiary Australian hospitals.

SUBJECTS AND METHODS

A retrospective review was performed on patients who underwent high computed tomography imaging of the neck. Scans were assessed for discrepancy in arytenoid vertical height discrepancy and compared to a cohort with known UVP.

RESULTS

44 normal patients (50% female, mean age 57.6 ± 14.8 years) were compared to 23 patients with UVP (43.4% female, mean age 52.3 ± 14.9 years.) Normal patients were found to have a smaller height discrepancy compared to UVP patients (student's t-test,2.00 mm ± 0.00 vs 2.39 mm ± 0.72, p < .001.) CONCLUSION: This study suggests that discrepancy is pathologic, and it is plausible that this results in acoustic consequences.

Arytenoid vertical height discrepancy in predicting outcomes after unilateral vocal cord medialization

OBJECTIVES/HYPOTHESIS

Unilateral vocal fold paralysis is a structural abnormality that often occurs secondary to dysfunction of the recurrent laryngeal nerve and typically presents as a breathy voice. Medialization laryngoplasty is a constellation of procedures that improves apposition of the vocal cords. Many patients, however, fail to experience sufficient improvement in vocal quality postoperatively despite apparent glottic closure on stroboscopy. This suggests that asymmetry in other cord characteristics may also have acoustic consequences. Our hypothesis is that arytenoid height symmetry may play a significant role in vocal quality. To our knowledge there are no human observational studies examining this topic. We therefore aimed to correlate asymmetry in arytenoid height and patient-reported satisfaction in voice quality after thyroplasty.

STUDY DESIGN

Retrospective cohort analysis.

METHODS

A retrospective review of prospectively collected data on consecutive patients who underwent medialization thyroplasty at a tertiary Sydney, Australia hospital was performed. Data collected included age, sex, onset of symptoms, as well as well as preoperative and 3-month postoperative maximum phonation time and Voice Handicap Index (VHI). Preoperative computed tomography scans were assessed for discrepancy of arytenoid vertical height discrepancy.

RESULTS

Twenty-three patients (56.5% female) with mean age of 52.4 ± 14.9 years were included. Most patients underwent injection thyroplasty (78.3%, n = 5), whereas the remaining underwent an open approach. A statistically significant inverse correlation was found between increasing height discrepancy and VHI improvement (r = -0.6, P = .003.) Revision surgery was associated with increased height discrepancy.

CONCLUSIONS

Findings of this study may affect future recommendations to address height discrepancy in surgery to treat unilateral vocal cord paralysis.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:418-422, 2020.

Surgical Impact of the Montgomery Implant System on Arytenoid Cartilage and the Paralyzed Vocal Fold

OBJECTIVES/HYPOTHESIS

Medialization thyroplasty (MT) has become a prominent method for treating glottal insufficiency. This study aimed to visualize the biomechanical influence of a medialization implant on arytenoid cartilage, particularly on the length and level of paralyzation in the vocal fold, in patients with unilateral vocal fold paralysis.

STUDY DESIGN

Prospective study.

METHODS

We recruited 15 patients (10 men, 5 women) with unilateral vocal fold paralysis that underwent MT with a Montgomery® thyroplasty implant. We performed high-resolution computed tomography of the arytenoid cartilage before and after MT and analyzed the three-dimensional images. To visualize the movement of the arytenoid and to measure the lengthening of the vocal fold, we superimposed pre- and postoperative 3D images with MIMICS software.

RESULTS

On the affected side, the implant pushed the arytenoid backwards. In addition, the vocal process of the arytenoid was inwardly rotated. These movements resulted in an elongated, augmented vocal fold on the affected side.

CONCLUSION

MT led to an elongated, medialized vocal fold on the treated side. After the intervention, the vocal folds on both sides were the same length in the phonatory position.

Factors Predicting the Recovery of Unilateral Vocal Fold Paralysis After Thyroidectomy

BACKGROUND

We used voice analysis and clinicopathological factors to explore the prognosis of unilateral vocal fold paralysis after thyroid surgery.

METHODS

The medical records of 63 females who developed unilateral vocal fold paralysis after thyroidectomy were reviewed. All patients were divided into two groups: those who recovered from vocal fold paralysis and those who did not. We analyzed clinical parameters and voice analysis results in a search for correlations with recovery from paralysis.

RESULTS

Of the 63 patients, 37 (58%) recovered from paralysis. A small tumor size, incomplete paralysis, the absence of arytenoid tilting, no compensatory movement of the normal side, lower postoperative shimmer, a higher postoperative maximum phonation time (MPT), and lower postoperative subglottic pressure correlated significantly with recovery from vocal fold paralysis. Multivariate analysis confirmed that the absence of compensatory movement of the normal side on videostroboscopy was independently prognostic. A postoperative MPT of 6.86 appeared to be optimal for prediction of recovery. Most patients recovered within 6 months, but those with incomplete paralysis recovered about 3 months earlier. At the 12-month follow-up, the thyroidectomy-related voice questionnaire scores had returned to preoperative values in only 12 patients (19.0%); 51 patients (81.0%) did not fully recover.

CONCLUSION

Compensatory movement of the normal side evident on videostroboscopy was a poor prognostic factor. Voice analysis can be helpful in counseling vocal fold paralysis patients after thyroidectomy, and early intervention may be considered in patients who are expected to have a poor prognosis.

Effect of level difference between left and right vocal folds on phonation: Physical experiment and theoretical study

As an alternative factor to produce asymmetry between left and right vocal folds, the present study focuses on level difference, which is defined as the distance between the upper surfaces of the bilateral vocal folds in the inferior-superior direction. Physical models of the vocal folds were utilized to study the effect of the level difference on the phonation threshold pressure. A vocal tract model was also attached to the vocal fold model. For two types of different models, experiments revealed that the phonation threshold pressure tended to increase as the level difference was extended. Based upon a small amplitude approximation of the vocal fold oscillations, a theoretical formula was derived for the phonation threshold pressure. This theory agrees with the experiments, especially when the phase difference between the left and right vocal folds is not extensive. Furthermore, an asymmetric two-mass model was simulated with a level difference to validate the experiments as well as the theory. The primary conclusion is that the level difference has a potential effect on voice production especially for patients with an extended level of vertical difference in the vocal folds, which might be taken into account for the diagnosis of voice disorders.

Unilateral Vocal Cord Paralysis Causes Contralateral False-Positive Positron Emission Tomography Scans of the Larynx

Positron emission tomography (PET) is used in the management of head and neck cancers. It identifies tissue with increased metabolic activity and is not specific for malignancy. A false-positive PET scan of the larynx is associated with vocal cord paralysis. We reviewed PET scan reports of patients with lung cancer from 1998 to 2001 to identify patients with increased 18-fluoro-2-deoxyglucose uptake in the larynx without a known history of head and neck cancer and then correlated this increased uptake with laryngoscopic findings. There were 17 patients who had a positive PET finding in the larynx. Fifteen of those had a false-positive PET scan in the larynx. All had contralateral vocal cord paralysis. Two patients were noted to have head and neck cancer. We conclude that vocal cord paralysis can cause a false-positive PET scan on the contralateral side of the larynx due to overactivity of laryngeal muscles that compensate for the paralyzed cord.

Quantitative Analysis of the Visor-Like Vertical Motion of the Cricoarytenoid Joint in the Living Subject

OBJECTIVES

The cricoarytenoid joint has a loose capsule and large cavity and may allow the arytenoid distanced from the cricoid cartilage. The objective was to quantify vertical motion of the arytenoid cartilage in the living subject.

STUDY DESIGN

This is a prospective study.

METHODS

Axial computed tomography images from 35 healthy subjects and seven patients with unilateral vocal fold paralysis were collected at inspiration and phonation. The perpendicular distance from the arytenoid vocal process (VP) or muscular process (MP) to the cricoid plane was measured and analyzed.

RESULTS

During phonation, the range of the vertical movement of the VP was significantly wider than that of the MP. The vertical motion varies in sides, sexes, and ages. The vertical gaps of the VP and MP between the paralyzed and contralateral sides were about 0.8 mm and 1.5 mm, respectively.

CONCLUSIONS

This study confirms a visor-like downward vertical motion of the arytenoid cartilage during phonation.

Unilateral vocal fold paralysis: can laryngoscopy predict recovery? A prospective study

OBJECTIVE

To determine the prognostic value of laryngoscopy in predicting the recovery of unilateral vocal fold paralysis.

METHOD

A prospective study was carried out of all patients with unilateral vocal fold paralysis without a progressive lesion or arytenoid dislocation.

RESULTS

Among the 66 candidates, 15 recovered. Patients with interarytenoid paralysis (p < 0.001) or posterolateral tilt of the arytenoid (p = 0.028) had less chance of recovery. Among 51 patients who did not recover, 25.49 per cent regained phonatory function by compensatory movement of the normal side; the rest required an intervention. Intervention requirement was significantly less for those patients who had isolated glottic level compensation. The paralysed vocal fold was at the same level in 32.35 per cent of patients, higher in 38.23 per cent and lower in 29.42 per cent. In those in whom vocal folds were in the abducted position (46.67 per cent), the affected vocal fold was at a lower position on phonation. Inter-observer reliability assessment revealed excellent to good agreement for all criteria.

CONCLUSION

Interarytenoid paralysis and posterolateral tilt of the arytenoid were predictors of poor recovery.

Posterior glottic gap and age as factors predicting voice outcome of injection laryngoplasty in patients with unilateral vocal fold paralysis

Objectives:

This study aimed to analyse demographic profiles and pre-injection stroboscopic findings for patients with unilateral vocal fold paralysis, to investigate possible predictive factors for voice outcomes of injection laryngoplasty.

Materials and methods:

Fifty-nine unilateral vocal fold paralysis patients underwent vocal fold augmentation, using transcutaneous Artecoll (polymethyl methacrylate microspheres plus bovine collagen) injection into the paralysed vocal fold via the cricothyroid space. Three months later, patients were divided into improved (n = 44) and unimproved (n = 15) groups, using the perceptual grade-roughness-breathiness-asthenia-strain scale, and their clinical characteristics and pre-operative stroboscopic findings compared.

Results:

The improved group were significantly younger than the unimproved group (p = 0.000). The size of the posterior gap on phonation was closely associated with the outcome of injection laryngoplasty (p = 0.015).

Conclusion:

Younger patients with a smaller posterior glottic gap on phonation can be expected to have a more favourable outcome following injection laryngoplasty for correction of glottic insufficiency due to unilateral vocal fold paralysis.

Arytenoid dislocation: An analysis of the contemporary literature

OBJECTIVES/HYPOTHESIS

To discuss the incidence, diagnosis, laryngeal findings, and management of arytenoid dislocation as a separate entity from vocal fold paralysis.

STUDY DESIGN

Literature review.

METHODS

A contemporary review of the literature was performed by searching the terms arytenoid cartilage dislocation and subluxation in various combinations. Articles were analyzed and selected based on relevance and content.

RESULTS

Arytenoid dislocation is described as an uncommon laryngeal finding associated with intubation or blunt laryngeal trauma. The majority of recent publications are case reports or small case series. Diagnosis of arytenoid dislocation with flexible laryngoscopy, helical computed tomography, videostroboscopy, and laryngeal electromyography is recommended. In most reported cases, diagnosis has been made based on the position of the arytenoid at laryngoscopy. Reduction and repositioning of the arytenoid cartilage is reported with limited success noted with delayed diagnosis. Speech therapy may also be a beneficial treatment option.

CONCLUSIONS

Although arytenoid dislocation is reported in the literature, the body of available evidence fails to sufficiently differentiate it as a separate entity from unilateral vocal fold paralysis. Flexible laryngoscopy is inadequate as a standalone procedure to distinguish arytenoid dislocation from laryngeal nerve injury.

Modified arytenoid adduction for cancer-related unilateral vocal fold paralysis

OBJECTIVES

(1) To evaluate the efficacy of modified arytenoid adduction in the management of patients with symptomatic cancer-related unilateral vocal fold paralysis, and (2) to assess the impact of this treatment on patients' quality of life.

METHODS

Forty-two patients with cancer-related unilateral vocal fold paralysis underwent modified arytenoid adduction between February 2001 and December 2008. Of these, 37 patients were enrolled in this retrospective study (one patient died of primary disease and four were lost to follow up). Laryngostroboscopy was performed to evaluate vocal fold orientation and mobility. Pre- and post-operative assessment of subjective and objective voice, aerodynamic parameters, and quality of life were also undertaken, and aspiration was subjectively rated.

RESULTS

Laryngostroboscopic findings indicated a significant post-operative improvement in vocal fold posterior glottal closure and vertical gap. Significant improvements in voice quality, aerodynamic parameters and quality of life were noted three months post-operatively in all patients (p < 0.01). The overall success rate for swallowing rehabilitation was 94.6 per cent (35/37). Subjective aspiration ratings decreased significantly post-operatively, compared with pre-operative values (p < 0.01). No major complication occurred in any patient, except for dyspnoea in one patient.

CONCLUSION

Modified arytenoid adduction is an effective and reliable medialisation technique which can restore satisfactory voice quality, prevent aspiration and lead to a better quality of life for patients with cancer-related unilateral vocal fold paralysis.

Arytenoid cartilage dislocation: a 20-year experience

SUMMARY

Arytenoid cartilage dislocation is an infrequently diagnosed cause of vocal fold immobility. Seventy-four cases have been reported in the literature to date. Intubation is the most common origin, followed by external laryngeal trauma. Decreased volume and breathiness are the most common presenting symptoms. We report on 63 patients with arytenoid cartilage dislocation treated by the senior author (RTS) since 1983. Significantly more posterior than anterior dislocations were represented. Although reestablishing joint mobility is difficult, endoscopic reduction should be considered to align the heights of the vocal processes. This process may result in significant voice improvement even long after the dislocation. Strobovideolaryngoscopy, laryngeal electromyography, and laryngeal computed tomography (CT) imaging are helpful in the evaluation of patients with vocal fold immobility to help distinguish arytenoid cartilage dislocation from vocal fold paralysis. Familiarity with signs and symptoms of arytenoid cartilage dislocation and current treatment techniques improves the chances for optimal therapeutic results.

Functional Significance of Arytenoid Adduction with the Suture Attaching to Cricoid Cartilage versus to Thyroid Cartilage for Unilateral Paralytic Dysphonia

OBJECTIVE

In the treatment of unilateral paralytic dysphonia, traditional arytenoid adduction is designed to place suture through the muscular process of the arytenoid attaching anteriorly to the thyroid ala. In contrast with the suture direction of this technique, a new paramedian approach to arytenoid adduction anchors anteroinferiorly to the cricoid cartilage, mimicking the force action of the lateral cricoarytenoid muscle (the major adductor of the larynx). This study investigated the influence of these changes in suture direction on the vocal fold level as well as the vocal outcomes in these two techniques of arytenoid adduction.

STUDY DESIGN

A prospective clinical series.

METHODS

Thirty patients with unilateral paralytic dysphonia underwent medialization laryngoplasty with arytenoid adduction and strap muscle transposition. Under local anesthesia, the thyroid lamina on the involved side was paramedially separated. The inner perichondrium was carefully elevated away from the overlying thyroid cartilage, carrying the dissection posteriorly to the level of the superior and inferior cornua. The lamina was retracted laterally, the inner perichondrium was opened near the midpoint, and the lateral cricoarytenoid muscle identified. Tracing the muscle fibers posterosuperiorly, the muscular process of the arytenoid was identified. A 2-0 Prolene suture was placed through the muscular process and temporarily tied to the anterolateral aspect of the thyroid ala (AA-thyroid suture). Intraoperative acoustic and perceptual assessments were performed. After releasing the tie, the suture was anchored to the cricoid cartilage at the origin of the lateral cricoarytenoid muscle (AA-cricoid suture). Voice assessments were repeated, and the outcomes of the two tests were compared. The choice of the type of arytenoid adduction suture was made intraoperatively according to which condition provided better vocal performance. After securing the suture, a bipedicled strap muscle flap was transposed into the space between the lamina and inner perichondrium and the thyroid cartilages sutured back into place.

RESULTS

The intraoperative acoustic and perceptual assessments revealed the vocal performance was significantly better with AA-cricoid suture than the AA-thyroid suture in this series. No major complications occurred in the study.

CONCLUSION

This study suggests that arytenoid adduction with suture attachment along the longitudinal axis of the lateral cricoarytenoid muscle to the cricoid cartilage is more physiologic and effective than that attaching the suture to the thyroid ala. A paramedian approach to arytenoid adduction with or without strap muscle transposition is a safe and effective method for treatment of unilateral paralytic dysphonia.

Clinical feasibility of the new technique of functional 3D laryngeal CT

CONCLUSIONS

Functional 3D laryngeal CT (F3DLxCT) is an informative tool for visualizing the active changes in length, tension and mass of the vocal folds for pitch control. Furthermore, volume defects and level differences of paralyzed vocal folds are easily detectable with this new technique.

OBJECTIVE

To evaluate the clinical feasibility of F3DLxCT images, which can provide clear coronal images of the vocal fold in each anteroposterior direction during phonation and in the resting state.

MATERIAL AND METHODS

FLxCT images were reconstructed to three dimensions to visualize laryngeal motion. FLxCT was performed in four normal controls and in four patients with unilateral vocal fold paralysis in the resting state and during phonation with three vowel sounds of different pitch. 3D images were reconstructed with segmentation and a surface-rendering algorithm on a PC, using the DICOM file of axial images.

RESULTS

The dynamic vocal fold 3D image during phonation could visualize that the thickness and volume were decreased in relatively to the pitch increase. Typical subglottic shoulder-like image formation and ventricular widening were noted with the high-pitch tone.

Laryngeal function and vocal fatigue after prolonged reading in individuals with unilateral vocal fold paralysis

The purpose of the present study was to examine the effect of prolonged loud reading, intended to induce fatigue, on vocal function in adults with unilateral vocal fold paralysis (UVFP). Subjects were 20 adults, 37-60 years old, with UVFP secondary to recurrent laryngeal nerve paralysis. Subjective ratings and instrumental measures of vocal function were obtained before and after reading. Statistical analysis revealed subjects rated their vocal quality and physical effort for voicing more severely following prolonged loud reading, whereas expert raters did not detect a significant perceptual difference in vocal quality. Reading fundamental frequency (F0) was significantly increased following prolonged loud reading, as were mean airflow rates at all pitch conditions. Maximum phonation times for comfort and low pitches significantly decreased during posttests. Multiple regression analyses revealed significant associations between ratings of posttest physical effort and select posttest measures. Interpretation of results indicates the prolonged loud reading task was successful in vocally fatiguing most of the UVFP subjects. Key physiologic correlates of vocal fatigue, in individuals with UVFP, include further reduction of glottic efficiency, resulting in decreased regulation of glottic airflow and a temporary destabilization of speaking fundamental frequency.

Aerodynamics, voice quality, and laryngeal image analysis of normal and pathologic voices

PURPOSE OF REVIEW

The purpose of this review is to describe examinations of phonatory function and their relation to image analysis of the unilaterally immobile larynx. Special emphasis was placed on image analysis using three-dimensional endoscopic images produced from CT scans.

RECENT FINDINGS

Developments in modern image processing technique have led to the quantification of various aspects of vocal fold vibration. Stroboscopic images of the vocal fold were digitized and, subsequently, the glottal gap area, amplitude, and degree of bowing were analyzed quantitatively in relation to phonatory function. Vocal fold vibration was observed with the aid of videokymography, during which images from a single transverse line can be recorded. Successive line images were shown in real time on a monitor, with the time dimension displayed in the vertical direction. This system enabled the assessment of left-right asymmetries, open quotient, propagation of mucosal waves, and forth. Three-dimensional endoscopic images derived from multislice CT scans provided a novel method for evaluating morphologic characteristics of the laryngeal lumen in relation to phonatory function. The combination of three-dimensional endoscopy and coronal reconstructed images supplemented stroboscopic findings exemplified by differences in vertical position and thickness between the vocal folds.

SUMMARY

Depth information about the vocal fold as well as the presence of paradoxic movement of the affected vocal fold and overadduction of the healthy vocal fold during phonation should be taken into account when surgical intervention to improve hoarseness resulting from unilateral vocal fold immobility is performed. Phonatory function tests, videostroboscopy, and laryngeal image analysis are prerequisites to achieving this goal.

Evidence-based treatment of paralytic dysphonia: making sense of outcomes and efficacy data

The criteria used to determine the success or failure of a given treatment for vocal fold paralysis are fundamental components of routine clinical practice and treatment outcomes research for the surgeon and voice therapist. The purpose of this article is to offer a guide to the critical interpretation of available measures of out-come and efficacy for this patient population. Such data form the basis for the practice of evidence-based medicine and voice therapy,essential if the standard of care is to evolve to the benefit of the patient. A better understanding of the potentials and limitations of each measure is important for treatment planning and patient counseling and, ultimately, for the conception of future well-designed clinical research. The complex issues regarding outcomes measurement are addressed here within the context of current treatment literature on vocal fold paralysis. Particular emphasis is placed on realistic data gathering within clinical practice.

Recurrent laryngeal nerve palsy in patients with lung cancer: detection with PET-CT image fusion -- report of six cases

Positron emission tomography (PET) with fluorodeoxyglucose (FDG) was performed for preoperative staging of lung cancer. In six of 184 patients, there was an intense FDG accumulation in the lower anterior neck. Fusion of PET and computed tomographic images revealed that the focal FDG uptake was localized in the internal laryngeal muscles. This finding was a result of compensatory laryngeal muscle activation caused by contralateral recurrent laryngeal nerve palsy due to direct nerve invasion by lung cancer of the left mediastinum or lung apices. The knowledge of this pitfall is important to avoid false-positive PET results.

Anterior and posterior medialization (APM) thyroplasty

OBJECTIVE

In unilateral vocal fold paralysis with dysphonia, most of the paralyzed vocal folds may be medialized effectively by medialization laryngoplasty. However, if the posterior glottal gap is wide, these procedures may sometimes have a limit to medialize the posterior glottis and cannot be effective for acceptable voice quality. The objective of this study is to introduce a new surgical technique for medializing the membranous and cartilaginous portions of the paralyzed vocal fold: anterior and posterior medialization (APM) thyroplasty.

METHOD

Six patients underwent APM thyroplasty. They completed preoperative and postoperative evaluation with acoustic analysis and video laryngoscopy.

RESULTS

All patients satisfied their voice subjectively after surgery. The paralyzed vocal folds, membranous and cartilaginous parts, were medialized well, and the paralyzed arytenoid showed less anterior tipping postoperatively. On voice analysis all patients showed prolonged phonation times and decreased perturbations after surgery.

CONCLUSION

The advantages of this procedure are to medialize the membranous and cartilaginous portions of the paralyzed vocal fold directly and to correct vertical mismatch between two vocal folds. This procedure might be especially indicated in the lateralized position of the paralyzed vocal fold but not in the higher paralyzed vocal fold compared with the normal vocal fold.