Physiologic assessment of arytenoid adduction

Intraoperative computed tomography imaging for laryngoplasty

OBJECTIVES

Intraoperative cone beam computed tomography (CBCT) imaging has the potential to facilitate the surgical procedure. The current preliminary retrospective chart review investigated the benefits of intraoperative CBCT during laryngoplasty.

METHOD

This study examined 26 cases that underwent intraoperative CBCT imaging during laryngoplasty, with one patient who counted twice due to first and revision surgery. The visual quality of structures of interest (glottal shape, thyroid cartilage, arytenoid cartilage, and implants) was determined using intraoperative CBCT during laryngoplasty. Each patient also underwent an aerodynamic assessment.

RESULTS

CBCT provided unique information, such as surgical landmarks in severe scarring, the subglottal shape, and the rotation angle of the arytenoid cartilage during arytenoid adduction. Nonetheless, 26.9% (7 of 26) of cases were affected by motion artifact, due to the long acquisition time. When motion artifact-negative cases were evaluated, 100% of glottal shape and more than 89% of thyroid cartilage were well visualized. All arytenoids were well-visualized in patients ≥ 50 years of age and without motion artifact, while CBCT failed to visualize the arytenoids in 2 of 4 patients who were < 50 years, due to the lack of calcifications. After medialization surgery, the yields of improved maximal phonation times (MPTs) in the motion artifact-negative and -positive groups were 8.7 sec and 3.4 sec, respectively (p = 0.032; Welch's t test). This comparison indicates intraoperative CBCT would contribute in MPT improvement, if CBCT is taken in measurable quality.

CONCLUSION

The potential benefits of intraoperative CBCT during laryngoplasty were demonstrated. A corollary, prospective study is warranted to further confirmation.

Postintubation Phonatory Insufficiency: A Challenging Diagnosis

INTRODUCTION

Glottic insufficiency is an important cause of dysphonia and can be frequently overlooked in the clinical evaluation. The differential diagnoses of this entity are diverse and include postintubation phonatory insufficiency (PIPI). These patients present with glottic insufficiency symptoms, associated with normal laryngeal imaging evaluation with no evident lesions. There is scarce literature describing this entity, since it is usually underdiagnosed.

OBJECTIVES

The aim of this study is to describe two clinical cases diagnosed with PIPI at our center's Voice Unit, discuss their clinical features, diagnostic evaluation, and treatment alternatives.

CASE SUMMARY

We report two clinical cases of prolonged orotracheal intubation (OTI) that developed dysphonia, vocal fatigue, a breathy voice, and poor vocal projection after being discharged from the hospital. Laryngoscopic evaluation showed no lesions in the membranous glottis and normal vocal fold mobility. Respiratory glottis was difficult to evaluate because of redundant arytenoids. To improve visualization, a laryngotracheoscopy with transtracheal anesthesia was performed in-office, exposing scar tissue medial to the vocal processes and respiratory vocal fold, confirming PIPI.

DISCUSSION

Prolonged OTI can damage the medial arytenoid mucosa producing a posterior glottic gap that determines symptoms of glottic insufficiency. Multiple treatment options have been described yet few achieve a sufficient closure of the defect, so management is initially based on counseling and speech therapy.

CONCLUSIONS

PIPI is usually difficult to diagnose and should be sought directly in the clinical evaluation, especially if there are no obvious lesions in the membranous glottis.

Effects of Sequentially Combined Arytenoid Adduction and Injection Laryngoplasty in Patients With Unilateral Vocal Fold Paralysis

OBJECTIVES

Arytenoid adduction (AA) and injection laryngoplasty (IL) are major surgical options for the treatment of unilateral vocal fold paralysis (UVFP). AA is a laryngeal framework surgery and IL is a soft-tissue augmentation procedure. Therefore, the effect of each intervention will not be substitutive but complementary to the other.

METHODS

Patients who received AA and IL were enrolled (N = 43). Mean age was 60.1 ± 12.7 years. Objective and subjective voice parameters including maximum phonation time (MPT), jitter, shimmer, noise to harmonic ratio (NHR), grade of dysphonia (G), and voice handicap index (VHI)-30 were collected preoperatively and 6 months postoperatively. AA and IL were sequentially performed with time interval; 28 (65.1%) patients received IL first followed by AA (IL+AA group) and 15 (34.9%) had AA followed by IL (AA+IL group). Time interval between first and second procedures was 9.9 ± 14.6 months.

RESULTS

MPT, jitter, shimmer, NHR, G and VHI-30 significantly improved by both first and second procedures (P < 0.001). When we evaluated IL+AA group and AA+IL group separately, the final outcomes of MPT, jitter, G, and VHI-30 between the two groups were not significantly different. When the overall effects of IL and AA were compared, MPT significantly improved with AA than with IL (P < 0.001).

CONCLUSION

In patients with unilateral vocal fold paralysis, sequential AA and IL (or IL and AA) provided additional improvement of subjective and objective voice parameters. Final outcomes of the two combined procedures resulted in similar degree of voice improvement regardless of the order of procedure.

LEVEL OF EVIDENCE

4.

Breathiness and Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) in Patients Undergoing Medialization Laryngoplasty With or Without Arytenoid Adduction

OBJECTIVES

We hypothesized that, in patients with unilateral vocal fold paralysis (UVFP), the auditory-perception of breathiness measured with Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) would be higher preoperatively in patients who undergo medialization laryngoplasty (ML) with arytenoid adduction (AA) compared to ML alone. We further hypothesized that increased breathiness would correlate with increased glottal area at maximum glottal closure.

STUDY DESIGN

Retrospective chart review.

METHODS

CAPE-V recordings were rated by expert judges in 105 subjects with UVFP (47 ML+AA and 58 ML). Component scores of the CAPE-V prior to laryngeal framework surgery and those at 3 and/or 12 months postoperatively were compared. Assessment of glottal area width during maximum glottal closure was attempted.

RESULTS

Breathiness scores prior to laryngeal framework surgery were significantly greater in UVFP patients having ML+AA compared to ML only (P < 0.001). Roughness was greater for ML only (P = 0.003). At 3 months, adjusted for age and previous injection laryngoplasty, the ML+AA group showed greater improvement for breathiness (P <0.001), loudness (P < 0.001), strain (P = 0.037), and pitch (P = 0.039), while the ML only group showed greater improvement in roughness (P = 0.009). Results were similar at 12 months. Only 26% of glottal area widths were ratable using methods previously described; therefore, no further analysis was attempted.

CONCLUSIONS

In patients with UVFP baseline perception of breathiness is greater in those clinically selected for ML+AA compared to ML only. Glottal area measurements were not representative of the UVFP cohort and more stringent criteria are needed for valid and reliable glottal area assessment when using clinical flexible stroboscopic exams. Findings support the idea that surgeons may be making decisions about AA based, to at least some degree, on auditory perceptual evaluation of voice.

Pyriform Sinus Mucosa Stabilization for Prevention of Postoperative Airway Obstruction in Arytenoid Adduction

Objectives:

The Isshiki arytenoid adduction procedure directly closes the open posterior glottis. Postoperative airway obstruction that necessitates emergent tracheotomy is an important complication in arytenoid adduction patients when the standard posterior thyroplasty window is used to approach the posterolateral larynx. Immediate postoperative fiberoptic laryngoscopy shows ipsilateral edema and/or hematoma of the arytenoid and supraglottic mucosa, with occasional obstructing inspiratory collapse. In this study, I sought to modify the posterior window approach during arytenoid adduction surgery, and thereby decrease the incidence of immediate postoperative airway obstruction.

Methods:

I performed a retrospective chart review of 246 arytenoid adduction patients, looking for immediate postoperative airway compromise.

Results:

There were no episodes of postoperative airway obstruction that necessitated tracheotomy in the first 30 patients in whom I approached the posterolateral larynx using the classic Isshiki techniques. Nine of the succeeding 132 adduction patients required emergent tracheotomy when the standard posterior window technique was used instead of a classic Isshiki approach (6.8%). In the most recent 84 patients, I used one tacking suture to stabilize the elevated pyriform sinus mucosa to the upper margin of the posterior window cartilage at closure. Four of the 84 patients had audible postoperative airway turbulence that abated with medical treatment, and 1 patient required an emergent tracheotomy (1.2%; p = .0495).

Conclusions:

Suture stabilization of the pyriform sinus mucosa is effective and is recommended for prevention of posterior glottic airway obstruction after arytenoid adduction when the posterior window technique is used.

Traction of Lateral Cricoarytenoid Muscle for Unilateral Vocal Fold Paralysis: Comparison with Isshiki's Original Technique of Arytenoid Adduction

Between 1995 and 1997, we performed Isshiki's original method of arytenoid adduction alone or as an adjunct to type I thyroplasty for the treatment of unilateral vocal fold paralysis. From 1997 onward, we performed arytenoid adduction by traction of the lateral cricoarytenoid muscle (Iwamura's method), because it reduces discomfort to the patient and avoids rotation of the thyroid cartilage. Preliminary experiments and surgical procedures involving traction of the lateral cricoarytenoid muscle are described. Of 21 patients with a maximum phonation time of less than 9 seconds, 14 underwent type I thyroplasty as an adjunct to our method of arytenoid adduction and 7 underwent arytenoid adduction alone. Sixteen patients (76%) were able after surgery to extend their maximum phonation time beyond 10 seconds; this result compares favorably with the results of Isshiki's original adduction technique. We describe useful anatomic landmarks for approaching the lateral cricoarytenoid muscle in the hope that more voice surgeons will adopt this approach in the treatment of unilateral vocal fold paralysis.

Arytenoid cartilage dislocation from external blunt laryngeal trauma: evaluation and therapy without laryngeal electromyography

Background

Intubation trauma is the most common cause of arytenoid dislocation. The aim of this study was to investigate the diagnosis and treatment of arytenoid cartilage dislocation from external blunt laryngeal trauma in the absence of laryngeal electromyography (LEMG) and to explore the role of early attempted closed reduction in arytenoids cartilage reposition.

Material/Methods

This 15-year retrospective study recruited 12 patients with suspected arytenoid dislocation from external blunt laryngeal trauma, who were evaluated through 7 approaches: detailed personal history, voice handicap index (VHI) test, indirect laryngoscope, flexible fiberoptic laryngoscope, video strobolaryngoscope, and/or high-resolution computed tomography (CT), and, most importantly, the outcomes after attempted closed reduction under local anesthesia. They were divided into satisfied group (n=9) and dissatisfied group (n=3) based on their satisfied with voice qualities at 1 week after the last closed reduction manipulation.

Results

Each patient was diagnosed with arytenoid dislocation caused by external blunt laryngeal trauma. In the satisfied group, VHI scores and maximum phonation time (MPT) at 1 week after the last reduction were significantly improved compared with those before the procedure (P<0.05). Normal or improved mobility and length of the affected vocal fold were also noted immediately after the end of the last closed reduction. The median time interval between injury and clinical intervention in satisfied group was 43.44±34.13 days, much shorter than the median time of 157.67±76.07 days in the dissatisfied group (P<0.05).

Conclusions

Multimodality assessment protocols are essential for suspected arytenoid dislocation after external blunt laryngeal trauma. Early attempted closed reduction should be widely recommended, especially in health facilities without LEMG, mainly, because it could be helpful for early diagnosis and treatment of this disease. In addition, early closed reduction could also improve the success of arytenoid reduction.

Superomedial submucosal partial arytenoidectomy for improved posterior glottic closure: surgical technique and case presentation

OBJECTIVE

Endoscopic medial partial arytenoidectomy has been described previously for expansion of the posterior glottic airway in bilateral vocal fold paralysis. Superomedial submucosal partial arytenoidectomy (SSPA), a modification of this technique, can improve glottic closure in the setting of an obstructing anteromedially prolapsed arytenoid. We present our surgical technique and a case example.

METHODS AND RESULTS

A 45-year-old man presented with dysphonia attributable to unilateral true vocal fold paralysis. Laryngoscopy revealed right true vocal fold atrophy and an anteriorly prolapsed right arytenoid cartilage preventing posterior glottic closure during adduction. Right SSPA and ipsilateral vocal fold injection augmentation were performed without complication. One-month and 11-month postoperative evaluations showed marked improvement in voice, with complete glottic closure. Quality-of-life assessment and patient report showed a durable result at 50 months.

CONCLUSION

SSPA may be a valuable technique in the management of breathy dysphonia associated with posterior glottic gap and other sequelae of the malpositioned arytenoid.

Framework Surgery for Treatment of Unilateral Vocal Fold Paralysis

Laryngeal framework surgery is the current gold standard treatment for unilateral vocal fold paralysis. It provides a permanent solution to glottic insufficiency caused by injury to the recurrent laryngeal nerve. Various modifications to the original Isshiki type I laryngoplasty procedure have been described to improve voice and swallowing outcomes. The success of this procedure is highly dependent on the experience of the surgeon as it epitomizes the intersection of art and science in the field. The following article reviews the evidence, controversies, and complications related to laryngoplasty for unilateral vocal fold paralysis. It also provides a detailed analysis of how and when arytenoid-positioning procedures should be considered, and summarizes the literature on postoperative outcomes.

[Treatment of glottal gap]

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

Initial investigation of anterior approach to arytenoid adduction in excised larynges

OBJECTIVES/HYPOTHESIS

Arytenoid adduction (AA) can dramatically improve voice quality in patients with vocal fold paralysis (VFP); however, it is technically challenging. We present an anterior approach to AA, where GORE-TEX suture attached to curled wire is passed through the thyroid cartilage or cricothyroid membrane via a guide needle and used to manipulate the muscular process of the arytenoid. Performing AA via an anterior approach leads to comparable aerodynamic and acoustic outcomes compared to traditional AA in an excised larynx model.

STUDY DESIGN

Repeated measures with each larynx serving as its own control.

METHODS

We performed thyroplasty followed by traditional and anterior AA on excised larynges with simulated VFP. Aerodynamic and acoustic measurements were recorded.

RESULTS

Anterior AA significantly improved aerodynamic (phonation threshold power: P = .003) and acoustic parameters (percentage jitter: P = .028; percentage shimmer: P = .001; signal-to-noise ratio: P = .034) compared to VFP in this excised larynx model. Anterior AA and traditional AA produced comparable improvements in all parameters (phonation threshold power: P = .256; percentage jitter: P = .616; percentage shimmer: P = .281; signal-to-noise ratio: P = .970).

CONCLUSIONS

Anterior AA is an alternative to traditional AA that is easier to perform and produces comparable improvements in laryngeal function.

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

Objectives

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

Methods

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

Results

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

Conclusion

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

Optimal arytenoid adduction based on quantitative real-time voice analysis

HYPOTHESIS

The optimal degree of arytenoid rotation for arytenoid adduction (AA) can be determined using quantitative real-time voice analysis.

STUDY DESIGN

Repeated measures with each larynx serving as its own control.

METHODS

Unilateral vocal fold paralysis (VFP) was modeled in five excised canine larynges. Medialization laryngoplasty (ML) was performed, followed by AA. The optimal degree of arytenoid rotation was determined using real-time measurements of vocal efficiency (V(E) ), percent jitter, and percent shimmer. After the optimal degree of rotation was determined, the arytenoid was hypo- and hyperrotated 10% ± 2% of the optimal angle to mimic hypoadducted and hyperadducted states. Aerodynamic, acoustic, and mucosal wave measurements were recorded.

RESULTS

Mean optimal angle of arytenoid adduction was 151.4 ± 2.5°. V(E) differed significantly across experimental conditions (P = .003). Optimal AA produced the highest V(E) of any treatment, but this value did not reach that produced in the normal condition. Percent jitter (P < .001) and percent shimmer (P < .001) differed across groups and were lowest for optimal AA. Mucosal wave amplitude of the normal (P = .001) and paralyzed fold (P = .043) differed across treatments. Amplitude of both folds was highest for optimal AA.

CONCLUSIONS

V(E) and perturbation parameters were sensitive to the degree of arytenoid rotation. Using real-time voice analysis may aid surgeons in determining the optimal degree of arytenoid rotation when performing AA. Testing this method in patients and determining if optimal vocal outcomes are associated with optimal respiratory and swallowing outcomes will be essential to establishing clinical viability.

Multiparameter comparison of injection laryngoplasty, medialization laryngoplasty, and arytenoid adduction in an excised larynx model

OBJECTIVES/HYPOTHESIS

Evaluate the effect of injection laryngoplasty (IL), medialization laryngoplasty (ML), and ML combined with arytenoid adduction (ML-AA) on acoustic, aerodynamic, and mucosal wave measurements in an excised larynx setup.

STUDY DESIGN

Comparative case study using ex vivo canine larynges.

METHODS

Measurements were recorded for eight excised canine larynges with simulated unilateral vocal fold paralysis before and after vocal fold injection with Cymetra. A second set of eight larynges was used to evaluate medialization laryngoplasty using a Silastic implant without and with arytenoid adduction.

RESULTS

IL and ML led to comparable decreases in phonation threshold flow (PTF), phonation threshold pressure (PTP), and phonation threshold power (PTW). ML-AA led to significant decreases in PTF (P = .008), PTP (P = .008), and PTW (P = .008). IL and ML led to approximately equal decreases in percent jitter and percent shimmer. ML-AA caused the greatest increase in signal-to-noise ratio. ML-AA discernibly decreased frequency (P = 0.059); a clear trend was not observed for IL or ML. IL significantly reduced mucosal wave amplitude (P = 0.002), whereas both ML and ML-AA increased it. All procedures significantly decreased glottal gap, with the most dramatic effects observed after ML-AA (P = 0.004).

CONCLUSIONS

ML-AA led to the greatest improvements in phonatory parameters. IL was comparable to ML aerodynamically and acoustically, but caused detrimental changes to the mucosal wave. Incremental improvements in parameters recorded from the same larynx were observed after ML and ML-AA. To ensure optimal acoustic outcome, the arytenoid must be correctly rotated. This study provides objective support for the combined ML-AA procedure in tolerant patients.

Localization of the muscular process for arytenoid adduction surgery

OBJECTIVES/HYPOTHESIS

Arytenoid adduction (AA) surgery can be technically challenging, potentially limiting its utilization in general practice. Because AA often serves as an adjunct to thyroplasty type I (TTI) in the management of unilateral vocal fold paralysis, this study sought to define the anatomic position of the muscular process (MP) of the arytenoid cartilage in relation to the TTI window and other key thyroid cartilage landmarks, thereby facilitating a more efficient surgical approach.

STUDY DESIGN

Cadaveric anatomic dissections.

METHODS

Arytenoid MPs were identified bilaterally in eight cadavers for a total of 16 hemilarynges. The location of the MP was measured relative to the anteroinferior corner of the traditional TTI window and also relative to the roots of the superior and inferior cornua for comparison with other studies.

RESULTS

: The muscular processes were located along an axial line extending posteriorly from the inferior border of the TTI window and parallel to the inferior border of the thyroid cartilage. In males, the mean distance to the MP was 26.9 mm from the anteroinferior corner of the window, whereas in females the mean distance was 18.9 mm. In all cases, the MP was inferior to the midpoint between the roots of the superior and inferior cornua (mean inferior offset = 2.7 mm).

CONCLUSIONS

The TTI window can be used intraoperatively to help locate the arytenoid muscular process during arytenoid adduction surgery.

Useful Landmarks in Arytenoid Adduction and Laryngeal Reinnervation Surgery

OBJECTIVE

Knowledge of the location of the muscular process of the arytenoid cartilage and the recurrent laryngeal nerve is essential to performing a successful arytenoid adduction and laryngeal reinnervation surgery. We describe external landmarks useful in locating these structures.

STUDY DESIGN

Cadaveric laryngeal dissection.

METHODS

Posterior laryngeal dissection was performed in 16 human larynges. The position of the muscular process of the arytenoid was measured bilaterally relative to the inferior and superior borders of the thyroid lamina. The recurrent laryngeal nerve was followed distally from slightly below the level of the cricothyroid joint to its genu where its vertical course changes to an oblique intralaryngeal course.

RESULTS

The muscular process of the arytenoid was usually found halfway between the roots of the superior and inferior cornu of the thyroid lamina. The recurrent laryngeal nerve was found just deep to the cricothyroid joint and lateral to the posterior cricoarytenoid muscle. There were no other nerves in this area.

CONCLUSIONS

This study finds that the superior and inferior borders of the thyroid lamina are useful intraoperative landmarks to locate the muscular process of the arytenoid. The cricothyroid joint provides a good starting point to locate the recurrent laryngeal nerve, which can be identified slightly deeper between it and the posterior cricoarytenoid muscle.

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.

Direct pull of lateral cricoarytenoid muscle for unilateral vocal cord paralysis

CONCLUSION

Lateral cricoarytenoid muscle-pull surgery (LCA pull) is a safe and effective method for the treatment of unilateral vocal cord paralysis.

OBJECTIVE

To evaluate the results of an improved method of LCA pull for unilateral vocal cord paralysis.

MATERIAL AND METHODS

Thirteen patients with unilateral vocal cord paralysis underwent LCA pull between April 2003 and January 2004. A small window was made in the posterior lower part of the thyroid cartilage and 2-3 mm in a cranial direction to the lower edge of the thyroid cartilage. The inner perichondrium was carefully removed to expose the LCA muscle. A 4-0 nylon suture placed through the LCA muscle was pulled to adduct the arytenoid and was tied to the anterior lower part of the thyroid cartilage. All cases were treated by LCA pull alone. In all cases, the maximum phonation time was measured and an auditory evaluation was performed using the grade, roughness, breathiness, asthenia and strain scale. The airflow rate was measured in five cases.

RESULTS

Vocal improvement was obtained in 11/13 cases (85%). One of the unimproved cases had cricoarytenoid joint ankylosis. No complications were observed.

A case of high-pitched diplophonia that resolved after a direct pull of the lateral cricoarytenoid muscle

Various approaches have been employed for the surgical treatment of unilateral vocal cord paralysis. Recently, we performed a direct pull of the lateral cricoarytenoid muscle in a case of high-pitched diplophonia with little difference between the right and left vocal cord levels and obtained favorable results. The patient was a 66-year-old male who consulted our hospital with chief complaints of husky voice and abnormal sensation in the pharyngolaryngeal region. Cerebellum/brainstem inflammation was diagnosed in February 2002 and appropriate treatment was instituted. Despite an improvement in the patient's systemic condition, right vocal cord paralysis remained. Although there were no abnormalities in the vocal range for ordinary speech, diplophonia was noted at high pitches, and synchronization could not be observed using stroboscopy. Therefore, the patient was operated on in October 2002. The high-pitched diplophonia disappeared and stroboscopy revealed favorable mucosal waves at high pitches. Thus, direct pulling of the lateral cricoarytenoid muscle appears to be a useful procedure, even in a case of mild unilateral vocal cord paralysis.

Nerve-muscle transplantation to the paraglottic space after resection of recurrent laryngeal nerve

OBJECTIVE

To evaluate a new method of nerve-muscle transplantation (NMT) to the paraglottic space after resection of the recurrent laryngeal nerve (RLN) during surgery for thyroid cancer.

DESIGN

Review of nine consecutive patients with RLN paralysis caused by the thyroid cancer before surgery.

METHOD

After the usual extirpation of the thyroid cancer with concomitant removal of the RLN, the lower part of the sternohyoid muscle approximately 1 cm in width and 2 cm in length with the ansa cervicalis nerve connected was inserted into the paraglottic space by way of anterior retraction of the thyroid ala with the inferior horn cut off. When the muscle or the nerve was adhesive to the cancer, the nerve-muscle on the opposite side was used with transfer through the space under the thyrohyoid muscles and the superior horn of thyroid ala.

RESULTS

The voice quality was good or fair after surgery. In most patients, the maximum phonation time was 10 seconds or longer, and the mean flow rate was lower than 200 mL/s. The vocal functions were good immediately after surgery and maintained good values for 2 years or more after surgery. Vocal fold atrophy was not found in any patient.

CONCLUSION

When the RLN is resected during surgery for thyroid cancer end-to-end anastomosis of the nerve is impossible, NMT to the paraglottic space is a useful method for preserving good voice and preventing atrophy of the vocal fold.

Perspectives on medialization laryngoplasty

Medialization laryngoplasty has become the new gold standard for the permanent management of patients with vocal fold paralysis and paresis. This article reviews the conceptual developments of the diagnosis and management of patients with vocal fold paresis and paralysis. We identify the specifics of operative decision-making as well as surgical complications associated with medializationlaryngoplasty. The role of revision surgery is detailed. We suggest a standardized evaluation using both objective and subjective data for analysis of surgical outcomes.

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.

Visual observations of glottal configuration and vocal outcomes in arytenoid adduction

Arytenoid adduction procedures involve approximation of the arytenoid cartilages with the goal of reducing posterior glottal gap size and improving voice. However, voice outcomes after arytenoid adduction are not always optimal and may be improved by precise use of suture placements, forces, and direction angles. The development of intraoperative methods of assessing optimal suture direction appears critical for achieving the best voice outcome. The goal of this study was to examine the relationship of visual classification of glottal configuration, digital measures of the glottis, acoustic and aerodynamic measures, and voice outcome. Our results suggested that visual classification of glottal configuration was not useful in distinguishing voice outcome, except for cases in which there was a large posterior glottal gap. In contrast, acoustic and aerodynamic measures were related to digitized glottal measures and may be developed into a useful method of intraoperative monitoring.

Glottal configuration, acoustic, and aerodynamic changes induced by variation in suture direction in arytenoid adduction procedures

Arytenoid adduction is a phonosurgical procedure in which the arytenoid cartilages are approximated to reduce posterior glottal gap size and improve voice. Voice outcomes following arytenoid adduction are not always optimal. The goal of this study was to systematically vary suture direction and force of pull on the arytenoid cartilages in a human excised laryngeal model to determine the optimal combination of factors for reducing glottal gap and improving voice. Several factors demonstrated significant effects. Changes in suture direction and force of pull affected glottal configuration in both the horizontal and vertical planes. Increased force of pull on the muscular process resulted in increased adduction of the vocal process for all suture directions. Changes in suture direction and force of pull also affected acoustic and aerodynamic measures of induced voice. Therefore, voice outcomes can be optimized with arytenoid adduction if the vocal fold plane is accurately adjusted.

A new paramedian approach to arytenoid adduction and strap muscle transposition for vocal fold medialization

OBJECTIVE

To develop a prosthesis-free medialization laryngoplasty for the treatment of glottal incompetence.

STUDY DESIGN

Twenty-two consecutive patients with glottal incompetence underwent vocal fold medialization using a new paramedian approach to arytenoid adduction and/or strap muscle transposition.

METHODS

Under local anesthesia, the thyroid lamina on the involved side was parasagittally separated 5 mm off the midline. The inner perichondrium was carefully freed from the overlying thyroid cartilage. After dividing the thyrohyoid and cricothyroid membranes, the lamina was retracted laterally, the inner perichondrium was opened, and the lateral cricoarytenoid muscle identified. Tracing the muscle fibers posterosuperiorly, the muscular process of the arytenoid was identified. A 2-0 or 3-0 Prolene suture was placed through the muscular process and tied to the cricoid cartilage at the origin of the lateral cricoarytenoid muscle. A bipedicled strap muscle flap was then transposed into the space between the lamina and the inner perichondrium and the thyroid cartilages sutured back into place. Pre- and postoperative voice evaluations measured mean fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, and maximal phonation time, as well as assessments of voice quality.

RESULTS

Vocal improvement was obtained in 95% (21 of 22) of patients. There was a significant improvement (P <.05) in all parameters except shimmer. No major complications were noted in any patient, except for dyspnea in one patient resulting from arytenoid overrotation.

CONCLUSION

The results suggest that a paramedian approach to arytenoid adduction combined with strap muscle transposition is a safe and effective method for treating glottal incompetence, particularly in patients with unilateral paralytic dysphonia.

Revision thyroplasty

To document surgical techniques for performing a revision thyroplasty operation and to describe the subjective and objective results of these operations. I undertook a retrospective review of all patients who have undergone thyroplasty in my practice. I identified patients who required revision of a previous thyroplasty and evaluated preoperative and postoperative video and audio analyses of the voice. I identified the surgical steps necessary for successful completion of a revision operation and noted any special findings made at surgery. Charts were reviewed and tabulated for reasons for failure of the first operation, efficacy of the second surgical approach, specific anatomic findings made at revision surgery, and types of surgery available for revision. Of 625 total thyroplasties in 331 patients, revision operations accounted for 61 operations in 48 patients. All thyroplasty operations were found to be revisable or reversible. Objective voice analysis for 35 operations in 32 patients revealed a statistically significant improvement in shimmer in women, and in harmonics-to-noise ratio in all patients. Subjective voice improvement occurred in 80% of patients after revision surgery. I conclude that revision thyroplasty is possible with all thyroplasty types, giving significant improvement in both shimmer (women) and harmonics-to-noise ratio (all patients). Although most voices are still abnormal on postoperative objective voice analysis, 80% of patients are subjectively improved.

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.

Laryngeal reinnervation with the hypoglossal nerve. I. Physiology, histochemistry, electromyography, and retrograde labeling in a canine model

This study was performed to determine whether the hypoglossal nerve (cranial nerve XI [XII]) would serve as a useful donor for laryngeal reinnervation by anastomosis to the recurrent laryngeal nerve (RLN). Twenty hemilarynges in 10 dogs were studied prospectively after XII-RLN anastomosis (group A; n = 5), split XII-RLN anastomosis (group B; n = 3), XII-RLN anastomosis with a 2-cm interposition graft (group C; n = 2), no treatment (group D; n = 5), RLN section (group E; n = 2), or ansa cervicalis-RLN anastomosis (group F; n = 3). Spontaneous activity was observed monthly by infraglottic examination through permanent tracheostomies and was recorded by electromyography. Laryngeal adductory pressure and induced phonation were obtained by stimulating the RLN while passing a pressure transducer balloon or humidified air through the glottis. At sacrifice, the laryngeal muscles were stained for adenosine triphosphatase to determine the ratio of type I to type II fibers. Retrograde labeling of the brain stem was performed with horseradish peroxidase. Infraglottic examination at 6 months showed a full range of adductory motion in groups A and B during the swallow reflex, comparable with that in group D. Groups C and F showed good bulk and tone, but little spontaneous motion. Group E remained paralyzed. Stimulation of the transferred nerves caused more activity in groups A and B than in the other groups; groups C and F partially adducted at high levels. The laryngeal adductory pressure responses of groups A and B were similar to those of group D. The XII-reinnervated larynges were capable of producing normal induced phonation. Retrograde labeling of the RLN showed that the reinnervating axons originated only in the hypoglossal nucleus. Electromyography of the reinnervated adductor muscles confirmed spontaneous activity in the dogs (awake). Histochemical analysis confirmed slow-to-fast transformation of both the posterior and lateral cricoarytenoid muscles, indicating that significant reinnervation occurred. We conclude that the hypoglossal nerve functions well as a donor for adductory reinnervation of the larynx.

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

OBJECTIVES/HYPOTHESIS

In unilateral vocal fold paralysis, it has been generally accepted that the paralyzed vocal fold presents at a higher level than a normally innervated vocal fold. In this study, we correlate the appearances of the paralyzed arytenoid and the differences in level between the paralyzed and innervated vocal folds.

STUDY DESIGN

Retrospective review using video-recorded images of larynx.

METHODS

A total of 38 patients were selected for this study who reported symptoms of voice change attributable to a paralyzed vocal fold unilaterally. Video recordings were obtained using the laryngeal telescope. The heights were assessed according to the paralyzed positions, status (inspiration or phonation), and appearances of the paralyzed arytenoid. The appearances of paralyzed arytenoid were further clarified as the portions of the medial surface of the arytenoid that were visualized.

RESULTS

In medial paralysis, the paralyzed vocal fold appeared mainly as being at an equal vertical level or as having no distinct difference from normal vocal fold during phonation. However, a few cases of medial paralysis showed a lower than normal or higher than normal vocal fold during phonation, depending on the appearance of the paralyzed arytenoid. In lateral paralysis, most of the paralyzed vocal folds were not higher than the innervated vocal folds during phonation.

CONCLUSIONS

The heights of paralyzed vocal folds were variable depending on the paralyzed positions, the status of the larynx, and appearances of the paralyzed arytenoid. The fact that the paralyzed vocal fold is at a higher level than the normal vocal fold should be reconsidered.

Arytenoid adduction and medialization laryngoplasty

Arytenoid adduction and medialization laryngoplasty have become the mainstay of static surgical rehabilitation of the larynx after vocal fold paralysis. The rationale for considering one versus a combination of the two procedures has not been well addressed. This article outlines the basic science of the procedures and the clinical technical modifications necessary to make the surgery easier.

Arytenoid adduction combined with Gore-Tex medialization thyroplasty

OBJECTIVE

To describe the technique of combined Gore-Tex medialization thyroplasty with arytenoid adduction and to determine the long-term vocal outcome of patients treated for unilateral vocal cord paralysis with this procedure.

STUDY DESIGN

A retrospective chart review and patient reevaluation for patients treated at The University of Iowa Hospitals and Clinics between May 1995 and June 1999.

METHODS

The review addressed patient demographics, perioperative and long-term complications, and voice outcomes. Details of the surgical technique are provided within the manuscript.

RESULTS

Seventy-two Gore-Tex medialization procedures were completed. Arytenoid adduction was included in 22 of these procedures. This subset of patients was compared with the patients treated with Gore-Tex alone. No major postoperative complications occurred in either group. Preoperative and postoperative voice and videostroboscopy data were available for 19 arytenoid adduction patients and 25 Gore-Tex alone patients. On a seven-point scale (6 [severely abnormal] --> 0 [normal voice]), the average patient rating of voice dysfunction improved from 4.2 to 1.6 (arytenoid adduction) and 4.5 to 2.8 (Gore-Tex alone). Maximum phonation time improved from 6.9 seconds to 16.7 seconds in the arytenoid adduction group. Subjective voice assessment employing the four-point GRBAS scale (3 [severely abnormal] --> 0 [normal]) identified average improvement from an overall grade of 2.1 to 0.8 arytenoid adduction and 2.2 to 1.5 in the Gore-Tex alone group. Improvement was identified in the vocal quality of breathiness from 1.9 to 0.2 (arytenoid adduction) and 1.9 to 0.9 (Gore-Tex alone).

CONCLUSIONS

The combined technique of Gore-Tex medialization thyroplasty and arytenoid adduction provide functional results that appear to exceed the improvement attained with medialization alone.

Progress in laryngeal framework surgery

This paper reviews progress in laryngeal framework surgery since it was first reported about 25 years ago. The success of this type of surgery requires both a basic knowledge of the physiology of phonation, in order to make decisions about the surgical procedure, and surgical skill, in order to accomplish the intended procedure successfully. The main reason for hoarseness is imperfect closure of the glottis, but the second most important reason for hoarseness, increased stiffness of the vocal fold, cannot be corrected by mere medialization of the vocal fold. Laryngeal framework surgery is different in concept from conventional surgery, which is intended to remove the lesion. Controversial points discussed here regarding type I thyroplasty include: (i) whether the cartilage window should be removed; (ii) materials for fixation of the window; and (iii) comparison of type I thyroplasty with arytenoid adduction. A new surgical treatment for spasmodic dysphonia and its results in three patients are described briefly. Surgery for raising the vocal pitch requires further improvement. In the future, laryngeal framework surgery will have wider application in treatment of dysphonias, such as asthenic voice due to atrophy in professional singers or aging, pitch problems in females and gender identity disorder and spasmodic dysphonia.

Combined arytenoid adduction and laryngeal reinnervation in the treatment of vocal fold paralysis

OBJECTIVE/HYPOTHESIS

Glottal closure and symmetrical thyroarytenoid stiffness are two important functional characteristics of normal phonatory posture. In the treatment of unilateral vocal cord paralysis, vocal fold medialization improves closure, facilitating entrainment of both vocal folds for improved phonation, and reinnervation is purported to maintain vocal fold bulk and stiffness. A combination of medialization and reinnervation would be expected to further improve vocal quality over medialization alone.

STUDY DESIGN

A retrospective review of preoperative and postoperative voice analysis on all patients who underwent arytenoid adduction alone (adduction group) or combined arytenoid adduction and ansa cervicalis to recurrent laryngeal nerve anastomosis (combined group) between 1989 and 1995 for the treatment of unilateral vocal cord paralysis. Patients without postoperative voice analysis were invited back for its completion. A perceptual analysis was designed and completed.

METHODS

Videostroboscopic measures of glottal closure, mucosal wave, and symmetry were rated. Aerodynamic parameters of laryngeal airflow and subglottic pressure were measured. A 2-second segment of sustained vowel was used for perceptual analysis by means of a panel of voice professionals and a rating system. Statistical calculations were performed at a significance level of P = .05.

RESULTS

There were 9 patients in the adduction group and 10 patients in the combined group. Closure and mucosal wave improved significantly in both groups. Airflow decreased in both groups, but the decrease reached statistical significance only in the adduction group. Subglottic pressure remained unchanged in both groups. Both groups had significant perceptual improvement of voice quality. In all tested parameters the extent of improvement was similar in both groups.

CONCLUSION

The role of laryngeal reinnervation in the treatment of unilateral vocal cord paralysis remains to be established.

Laryngeal framework surgery for the management of aspiration

BACKGROUND

During the past decade, laryngeal framework surgery has become the treatment of choice for the management of adductor paralysis of the vocal fold. The primary impetus for the use of this technique has been on the rehabilitation of voice. The purpose of this study was to ascertain the effectiveness of laryngeal framework surgery, including medialization laryngoplasty with silicone (MLS), with or without arytenoid adduction (AA), on eliminating aspiration, improving diet, and aiding in the subsequent decannulation of individuals with glottic insufficiency secondary to vocal fold palsy.

METHODS

A retrospective chart review was performed on all patients initially seen with vocal cord paralysis who were treated with laryngeal framework surgery from June 1992 to April 1996. The study comprised 70 patients, including 31 women and 39 men, with a median age of 57 years. Clinical information was obtained regarding the etiology of the lesion, characteristics of the vocal cord deficit, history of aspiration, the presence of other neurologic deficits or concurrent pulmonary disease, treatment, and outcome. To determine the effectiveness of MLS, with or without AA, we assessed the final outcome regarding the presence and degree of aspiration, diet, history of aspiration pneumonia, and decannulation.

RESULTS

Seventy patients underwent 77 MLS (three bilateral, four revisions), and 21 AA. Decreased aspiration was obtained in 96% of our patients. Seventy-five percent of those patients who had required a tracheotomy were decannulated.

CONCLUSIONS

These results support the use of laryngeal framework surgery for the effective treatment of aspiration in selected patients initially seen with deficits of the glottic closure secondary to vocal fold paralysis or paresis.

Arytenoid adduction as an adjunct to type I thyroplasty for unilateral vocal cord paralysis

BACKGROUND

Surgical management of unilateral vocal cord paralysis has evolved over the last three decades. The recent use of type I thyroplasty has resulted in improvements in voice, swallowing, and respiration. The study was performed to evaluate our experience in 28 patients undergoing arytenoid adduction as part of their surgical rehabilitation of unilateral vocal cord paralysis.

METHODS

Patients undergoing arytenoid adduction with or without silastic medialization for unilateral vocal cord paralysis were entered into a prospective data base. Evaluation included symptomatic improvement in hoarseness, aspiration, dysphagia, dyspnea, and the radiographic documentation of pneumonia. Objective evaluation included mean phonatory air flow and acoustic analysis. Complications associated with surgery were recorded.

RESULTS

A satisfactory result was obtained in 27 of 28 (96%) patients. By symptom, improvement in hoarseness was evident in 96%, dyspnea 80%, dysphagia 94%, and aspiration 84%. Improvements in phonatory flow rate (p < .001), estimated mean laryngeal airway resistance (p < .001), and maximally prolonged phonation (p < .01) were identified. Complications occurred in 18% and consisted of local wound sepsis (n = 1), hematoma (n = 1), seroma (n = 1), and transient airway edema (n = 2). There were no episodes of airway obstruction requiring tracheostomy or implant extrusion.

CONCLUSIONS

Arytenoid adduction as part of type I thyroplasty is a safe and effective procedure. Subjective analysis confirms marked improvement in laryngeal function in the form of speech, swallowing, and respiration. Objective analysis confirms improvement in voice parameters. Future directions will focus on determination of those patients best served by arytenoid adduction.

Biomechanics of combined arytenoid adduction and medialization laryngoplasty in an ex vivo canine model

Arytenoid adduction (AA) and medialization laryngoplasty (ML) are being performed concurrently in patients with unilateral vocal fold paralysis with a large posterior glottal gap. The biomechanical effects of this combined procedure on the larynx have not been studied. An excised canine larynx model was used to study the effects of AA, ML, and combined AA and ML (AA-ML) on vocal fold configuration (length and degree of medialization) and tension. AA-ML lengthens the affected vocal fold relative to the opposite vocal fold, although both were slightly shortened compared with the control state (nonsignificant trends). AA-ML medializes the entire length of the vocal fold more effectively than AA or ML alone. Midmembranous vocal fold tension did not increase with AA-ML. With AA-ML, the vocal process resisted significantly greater lateralizing forces than with the control state or ML. We conclude that in an excised canine model, AA-ML combines the biomechanical properties of AA and ML. The larynx appears to be divided into 2 biomechanical subunits: membranous vocal fold (anterior) and arytenoid cartilage (posterior). When surgical rehabilitation of both laryngeal subunits is required, AA-ML appears to be a better choice than AA or ML alone.

Vocal mechanics as the basis for phonosurgery

OBJECTIVE

A number of modifications in laryngoplastic phonosurgery have recently been proposed. This report is intended to clarify the concept on which the surgery should be based, vocal mechanics, for further rational development of the surgery.

STUDY DESIGN

The results of various previous surgeries were compared. In an attempt to elucidate what makes the difference in the results, simulation of voice production was conducted with the use of excised larynges.

METHODS

Excised larynges were mounted on a tube so as to be blown from below. Experimental variables in the model included the glottal area initially set, stiffness of the vocal folds, and subglottal pressure. The conditions under which the voice became hoarse were examined.

RESULTS

The voice became hoarse under the following major conditions: 1) the initial glottal area exceeded a certain value, 2) stiffness was too high, and 3) the glottis was too tightly closed. Clinical representation for each condition was made, particularly for excessively tight glottal closure such as in spasmodic dysphonia. A new type of surgical treatment for spasmodic dysphonia, lateralization thyroplasty, was briefly reported, which restored the voice to normal without recurrence for 1 year at the time of this writing.

CONCLUSIONS

A potential new type of laryngoplastic phonosurgery should be conformed to the mechanics of voice production. In treating dysphonia, it is often necessary to switch from etiologic or radical treatment, if infertile, to symptomatic treatment instead, at the level of mechanics.

Biomechanics of arytenoid adduction surgery in an ex vivo canine model

The biomechanics of arytenoid adduction surgery are not well understood. An excised canine larynx model was used to study the effects of variable suture tension on glottal configuration and on vocal fold tension (at the midfold and the vocal process). Arytenoid adduction both medializes the vocal fold and closes a posterior glottal chink. Vocal fold tension at the midfold did not vary significantly with suture tension. As suture tension increased to approximately 100 g, vocal fold tension at the vocal process also increased. Beyond 100 g of suture tension, vocal fold tension at the vocal process did not increase. We conclude that the effects of suture tension on the resistance to lateral movement are different at the midfold compared to the vocal process. Procedures for surgical rehabilitation of vocal fold paralysis should address the biomechanical subunits of the larynx individually in order to achieve optimum results.

Laryngeal framework surgery for the management of aspiration in high vagal lesions

PURPOSE

The purpose of this study is to ascertain the effectiveness of laryngeal framework surgery, including medialization thyroplasty (MT), with or without arytenoid adduction (AA), on preventing aspiration, improving diet, and aiding in the subsequent decannulation of individuals with high vagal lesions.

PATIENTS AND METHODS

A retrospective chart review was performed on each patient presenting with a high vagal lesion who was treated with laryngeal framework surgery from June 1992 to April 1996 at a university medical center. Thirty-five patients were identified; there were 20 women and 15 men, with a median age of 51. Information regarding etiology of the lesion, characteristics of the vocal cord deficits, degree of aspiration, the presence of other neurologic deficits and concurrent pulmonary disease, treatment, and outcome was obtained. The final outcome regarding voice, the presence and degree of aspiration, diet, and decannulation following MT, with or without AA, was assessed to determine the effectiveness of these procedures.

RESULTS

Thirty-five patients underwent 40 MTs and 19 AAs. Ninety-four percent of patients who experienced aspiration improved, and 79% who had required tracheotomy were decannulated. Ninety percent of patients were noted to have subjective improvement in voice postoperatively.

CONCLUSION

Laryngeal framework surgery improves airway, deglutition, and voice in individuals suffering from high vagal lesions, and facilitates the rehabilitation of these patients.

Quantitative criteria for predicting thyroplasty type I outcome

The purpose of this study was to ascertain the relation between preoperative glottal gap and postoperative vocal function in thyroplasty type I. Twenty-two of 64 patients who underwent thyroplasty type I between 1987 and 1994 were studied. In preoperative digitized laryngostroboscopic images, the glottal-gap, width (GGW), shape, and area were examined at the maximum closure of vibration and normalized by membranous vocal-fold length (MVFL). Postoperative vocal function analysis was performed with aerodynamic and acoustic measurements and compared with preoperative videostroboscopic images. In patients with preoperative posterior GGW of less than 10% of MVFL, postoperative vocal function was significantly better than in other patients. Although thyroplasty type I is an excellent medialization technique, it may need to be combined with a posterior closure procedure in patients with large posterior gaps.

Magnetic resonance imaging (MRI) assessment of vocal fold medialization surgery

Historically, clinicians have used subjective assessment and perceptual judgments, supplemented with acoustic measures, aerodynamic studies, and videostroboscopy, to determine the effects of phonosurgery. When phonosurgical results are poor, magnetic resonance imaging (MRI) can be useful in determining how the surgical modifications contributed to the anatomical and functional status of the vocal folds. The authors present examples of MRI following vocal fold medialization by injection, thyroplasty, and arytenoid adduction. Findings reveal that the superior contrast resolution of MRI can precisely identify placement and persistence of injected implants and is particularly helpful in showing effects of the size and shape of alloplastic prostheses on vocal fold displacement. Such information is useful in troubleshooting suboptimal results and in planning revision thyroplasty by defining modification in the design of prostheses and the placement of cartilaginous windows in medialization thyroplasty. MRI can also aid in confirming indications for and limitations of certain procedures.