A comparative study of cricotracheal resection and staged laryngotracheoplasty for adult subglottic stenosis.

OBJECTIVE: Cricotracheal resection (CTR) and laryngotracheoplasty (LTP) are open surgical treatments for severe subglottic stenosis. This study aims to compare the applications and outcomes of these techniques. METHOD: Patients with subglottic stenosis at a tertiary academic institution from 2000 to 2012 were identified by diagnosis codes. Patients who underwent LTP or CTR were included. Records were reviewed for treatment data and outcomes. Patients with a history of head and neck malignancy or stenosis without cricoid involvement were excluded. RESULT: Sixty-one and 20 patients underwent LTP and CTR, respectively. When comparing patients receiving LTP and CTR, there was a significant difference in stenosis etiology (P=.014). The groups were similar in Cotton-Myer grade (P=.102). At last follow-up, 80.3% of LTP patients and 90.0% of CTR patients were decannulated. On multivariate analysis, there was a significant association between stenosis grade and decannulation in the LTP group (P=.01). Decannulation was not associated with stenosis grade in the CTR group. In both groups, there was no significant association between decannulation and sex, stenosis etiology, or stenosis length. CONCLUSION: Cricotracheal resection and LTP have both shown excellent long-term decannulation rates. Etiology and stenosis grade are likely to be determining factors when recommending specific surgical interventions for subglottic stenosis.

Neuromuscular induced phonation in a human ex vivo perfused larynx preparation.

Considering differences in laryngeal anatomy, degree of control, and range of voice qualities between animals and humans, investigations of the neuromuscular process of voice control are better conducted using a living human larynx in which parametric stimulation of individual laryngeal muscles is possible. Due to difficulties in access and monitoring of laryngeal muscle activities, such investigations are impossible in living human subject experiments. This study reports the recent success in developing an ex vivo perfused human larynx model, which allows parametric muscle stimulation and observation of its influence on phonation of a virtually living human larynx in a well-controlled laboratory environment.

Surgery or botulinum toxin for adductor spasmodic dysphonia: a comparative study.

OBJECTIVES: Currently, botulinum toxin (Botox) injection is the standard of treatment for adductor spasmodic dysphonia (ADSD). We sought to compare the outcome of selective laryngeal adductor denervation-reinnervation (SLAD-R) surgery for ADSD to that of Botox injections. METHODS: Patient-oriented measures (VHI-10) and objective single-blinded gradings of digital voice recordings were utilized as outcome measures. The surgical cohort, recruited by retrospective patient selection, consisted of 77 patients with a mean follow-up time of 7.54 +/- 2.55 years (range, 2.2 to 14.2 years). The injection cohort, recruited prospectively, included 28 patients with a mean follow-up time of 46.37 +/- 5.51 days (range, 36 to 54 days). RESULTS: As measured by the VHI-10, the surgical patients had significantly improved voice handicap outcome scores (mean, 14.4 +/- 13.6) as compared to the patients who had Botox injection (mean, 26.5 +/- 12.1; p = 0.001). Aside from VHI-10 item 2, the surgical group demonstrated significantly improved voice-related function on each VHI-10 component (p = 0.01). Within the injection subgroup, 88% agreed that Botox successfully treats their ADSD, yet only 63% agreed that Botox improves their speech consistently. Within the surgical subgroup, 82% would recommend this surgery to others, and 78% agreed that their voice was actually better after surgery than after Botox. Objective voice ratings demonstrated similar levels of breathiness and overall voice quality in the treatment subgroups. CONCLUSIONS: When indicated, the SLAD-R surgery for ADSD demonstrates outcomes equal to or superior to those of the current standard of Botox injections.

Laryngeal Manifestations of Ehlers-Danlos Syndrome.

OBJECTIVES: The identification of voice and airway manifestations of Ehlers-Danlos Syndrome (EDS), diagnoses, and potential treatment modalities. STUDY DESIGN: Single institution retrospective case series. METHODS: We examined all patients presenting to our institution over a span of 10 years with a history of EDS or who were subsequently diagnosed with EDS after their evaluation. Demographic and clinical data were collected. RESULTS: Four patients were identified with an underlying diagnosis of EDS. All four patients were heavy voice users. All four patients had history and/or stroboscopy findings suggesting vocal hyperfunction, which we suspect is due to EDS-related hypermobility of the cricoarytenoid joint or fragility of the superficial lamina propria. Two patients also had respiratory symptoms - one with respiratory muscle weakness and sensation loss and one with inducible laryngeal obstruction. All patients were treated with voice therapy with subsequent improvement in their symptoms. CONCLUSIONS: Patients with EDS may present to laryngology clinics with symptoms of dysphonia or dyspnea secondary to their underlying condition. Voice therapy is a low-risk and potentially beneficial treatment in this patient population.

Correlating Perceptual Voice Quality in Adductor Spasmodic Dysphonia With Computer Vision Assessment of Glottal Geometry Dynamics.

PURPOSE: This study examined the relationship between voice quality and glottal geometry dynamics in patients with adductor spasmodic dysphonia (ADSD). METHOD: An objective computer vision and machine learning system was developed to extract glottal geometry dynamics from nasolaryngoscopic video recordings for 78 patients with ADSD. General regression models were used to examine the relationship between overall voice quality and 15 variables that capture glottal geometry dynamics derived from the computer vision system. Two experts in ADSD independently rated voice quality for two separate voice tasks for every patient, yielding four different voice quality rating models. RESULTS: All four of the regression models exhibited positive correlations with clinical assessments of voice quality (R 2s = .30-.34, Spearman rho = .55-.61, all with p < .001). Seven to 10 variables were included in each model. There was high overlap in the variables included between the four models, and the sign of the correlation with voice quality was consistent for each variable across all four regression models. CONCLUSION: We found specific glottal geometry dynamics that correspond to voice quality in ADSD.

An updated review of the epidemiological factors associated with recurrent respiratory papillomatosis.

OBJECTIVES: To identify studies evaluating the epidemiology of recurrent respiratory papillomatosis (RRP), including patient demographics, human papillomavirus (HPV) immunology, clinical course, surgical and medical treatments, and psychosocial factors. METHODS: A systematic literature search through PubMed was performed to identify studies evaluating the epidemiological factors associated with RRP. All studies were screened through a priori selection criteria using the titles and abstracts. RESULTS: A total of 208 studies were identified, of which 54 met eligibility criteria and were included in the review. CONCLUSIONS: RRP is a rare disease most commonly caused by HPV 6 and 11. It is characterized by recurring benign papillomatous lesions in the respiratory tract, particularly the larynx. Existing evidence about disease risk factors is limited but includes both maternal HPV infection and patient smoking and sexual behaviors. Disease management involves a combination of routine surgical and medical treatment. Surgical techniques include CO2-laser, sharp dissection, coblation, microdebridement, and photoangiolytic laser. Medical treatments which have been found to facilitate disease control off-label include interferon-alpha (IFN-α), indole-3-carbinol, acyclovir, bevacizumab, retinoids, and the Gardasil and mumps vaccines. Many patients suffer from additional psychosocial challenges related to their diagnosis. Current disease knowledge remains limited, and more robust controlled trials about risk factors, medical therapies, and surgical options are needed. LEVEL OF EVIDENCE: 5.

Lessons learned from open laryngotracheal airway resection and primary anastomosis in high risk patients.

OBJECTIVE: Laryngotracheal stenosis is one of the most difficult conditions treated by the Otolaryngologist. Open resection of stenosis with primary airway anastomosis is the definitive treatment for this condition. However, some patients are considered high risk candidates for open airway surgery and management and outcomes in this group have not been reported. The purpose of this investigation is to identify a series of high risk patients who underwent open laryngotracheal surgery and detail the lessons learned in regards to their post-operative course and outcomes. METHODS: A retrospective cohort study of all patients that underwent airway resection and primary anastomosis over a fifteen-year period was performed. High-risk patients, those with medical comorbidities that impair wound healing, were identified. Post-operative course, management of complications, and ultimate airway outcomes were noted. RESULTS: Seven patients fitting the high-risk category were identified. Comorbidities were poorly controlled insulin dependent diabetes mellitus (N = 4), poorly controlled hypertension (N = 4), end stage renal disease requiring hemodialysis (N = 3), chronic obstructive pulmonary disease (N = 1), and history of radiation therapy (N = 1). Each patient suffered postoperative complications of varying degrees including postoperative infection (N = 1), formation of granulation tissue at the anastomotic site (N = 3), and postoperative hematoma (N = 1). Management included treatment of infection and complications. Anastomotic dehiscence was managed with tracheostomy and T-tubes. CONCLUSIONS: High-risk medical comorbidities may not be absolute contraindications for open laryngotracheal resection of airway stenosis. However, this experience emphasizes the importance of preoperative medical optimization and comprehensive postoperative care.

Transoral Robotic Surgical Proficiency Via Real-Time Tactile Collision Awareness System.

OBJECTIVES: In 2009, the Food and Drug Administration approved the use of the surgical robotic system for removal of benign and malignant conditions of the upper aerodigestive tract. This novel application of robotic-assisted surgery, termed transoral robotic surgery (TORS), places robotic instruments and camera system through the mouth to reach recessed areas of the pharynx and larynx. Over the successive decade, there was a rapid adoption of TORS with a surgical growth rate that continues to increase. Despite the rapid clinical acceptance, the field of TORS has not yet seen substantive changes or advances in the technical shortcomings, the lack of which has restricted objective TORS-specific surgical skills assessment as well as subsequent skills improvement efforts. One of the primary technical challenges of TORS is operating in a confined space, where the robotic system is maneuvered within the restrictive boundaries of the mouth and throat. Due to these confined boundaries of the pharynx, instruments can frequently collide with anatomic structures such as teeth and bone, producing anatomic collisions. Therefore, we hypothesized that anatomic collisions negatively impact TORS surgical performance. Secondarily, we hypothesized that avoidance of unwanted anatomic collisions could improve TORS surgical proficiency. METHODS: Design and fidelity testing for a custom TORS training platform with an integrated anatomic collision-sensing system providing real-time tactile feedback is described. Following successful platform assembly and testing, validation study using the platform was carried through prospective surgical training with trial randomization. Twenty otolaryngology-head and neck surgery residents, each trainee performing three discrete mock surgical trials (n = 60), performed the initial system validation. Ten of the 20 residents were randomized to perform the surgical trials utilizing the real-time feedback system. The remaining 10 residents were randomized to perform the surgical trials without the feedback system, although the system still could record collision data. Surgical proficiency was measured by Global Evaluative Assessment of Robotic Skills (GEARS) score, time to completion, and tumor resection scores (categorical scale ranging 0-3, describing the adequacy of resection). RESULTS: Major anatomic collisions (greater than 5N of force) negatively affected GEARS robotic skills. A mixed model analysis demonstrated that for every additional occurrence of a major collision, GEARS robotic skills assessment score would decrease by 0.29 points (P = .04). Real-time collision awareness created significantly fewer major (> 5 N) anatomic collisions with the tactile feedback system active (n = 30, mean collisions = 2.9 ± 4.2) as compared with trials without tactile feedback (n = 30, mean collisions = 12.53 ± 23.23) (P < .001). The second assessment measure of time to completion was unaffected by the presence of collisions or by the use of tactile feedback system. The third proficiency assessment was measured with tumor resection grading. Tumor resection scores was significantly (P = .02) improved with collision awareness system activated than trials without collision awareness. CONCLUSION: In order to test our primary hypothesis, a novel TORS training platform was successfully developed that provides collision force measurements including frequency, severity, and duration of anatomic collisions. Additionally, the platform was modulated to provide real-time tactile feedback of the occurrence of out-of-field collisions. Utilizing this custom platform, our hypothesis that anatomic collisions during TORS diminishes surgical performance was supported. Additionally, our secondary hypothesis that subsequent reduction of anatomic collisions improves TORS proficiency was supported by the surgical trial. Dedicated investigation to characterize the effect size and clinical impact is required in order to translate this finding into training curriculums and into clinical utilization. LEVEL OF EVIDENCE: II (Randomized trial) Laryngoscope, 130:S1-S17, 2020.

Bilateral Vocal Fold Medialization: A Treatment for Abductor Spasmodic Dysphonia.

INTRODUCTION: Abductor spasmodic dysphonia, a difficult-to-treat laryngologic condition, is characterized by spasms causing the vocal folds to remain abducted despite efforts to adduct them during phonation. Traditional treatment for abductor spasmodic dysphonia-botulinum toxin injection into the posterior cricoarytenoid muscle-can be both technically challenging and uncomfortable. Due to the difficulty of needle placement, it is often unsuccessful. The purpose of this investigation is to present a previously undescribed treatment for abductor spasmodic dysphonia-bilateral vocal fold medialization. METHODS: A retrospective case review of all cases of abductor spasmodic dysphonia treated in a tertiary care laryngology practice with bilateral vocal fold medialization over a 10-year period was performed. The Voice Handicap Index and the Voice-Related Quality of Life surveys were utilized to assess patient satisfaction with voice outcome. RESULTS: Six patients with abductor spasmodic dysphonia treated with bilateral vocal fold medialization were identified. Disease severity ranged from mild to severe. All six patients reported statistically significant improvement in nearly all Voice Handicap Index and Voice-Related Quality of Life parameters. They reported fewer voice breaks and greater ease of communication. Results were noted immediately and symptoms continue to be well controlled for many years following medialization. CONCLUSIONS: Bilateral vocal fold medialization is a safe and effective treatment for abductor spasmodic dysphonia. It is performed under local anesthesia and provides phonation improvement in the short and long term.

On the Legacy of Genetically Altered Mouse Models to Explore Vestibular Function: Distribution of Vestibular Hair Cell Phenotypes in the Otoferlin-Null Mouse.

OBJECTIVES: Early in his career, David Lim recognized the scientific impact of genetically anomalous mice exhibiting otoconia agenesis as models of drastically compromised vestibular function. While these studies focused on the mutant pallid mouse, contemporary genetic tools have produced other models with engineered functional modifications. Lim and colleagues foresaw the need to analyze vestibular epithelia from pallid mice to verify the absence of downstream consequences that might be secondary to the altered load represented by otoconial agenesis. More generally, however, such comparisons also contribute to an understanding of the susceptibility of labyrinthine sensory epithelia to more widespread cellular changes associated with what may appear as isolated modifications. METHODS: Our laboratory utilizes a model of vestibular hypofunction produced through genetic alteration, the otoferlin-null mouse, which has been shown to exhibit severely compromised stimulus-evoked neurotransmitter release in type I hair cells of the utricular striola. The present study, reminiscent of early investigations of Lim and colleagues that explored the utility of a genetically altered mouse to explore its utility as a model of vestibular hypofunction, endeavored to compare the expression of the hair cell marker oncomodulin in vestibular epithelia from wild-type and otoferlin-null mice. RESULTS: We found that levels of oncomodulin expression were much greater in type I than type II hair cells, though were similar across the 3 genotypes examined (ie, including heterozygotes). CONCLUSION: These findings support the notion that modifications resulting in a specific component of vestibular hypofunction are not accompanied by widespread morphologic and cellular changes in the vestibular sensory epithelia.

Research priorities in spasmodic dysphonia.

OBJECTIVE: To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia. STUDY DESIGN AND SETTING: A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities. RESULTS: Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. CONCLUSIONS: The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. SIGNIFICANCE: This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.

Hylan B gel restores structure and function to laser-ablated canine vocal folds.

OBJECTIVES: We evaluated cross-linked hyaluronic acid (hylan B gel) as a scaffold for tissue regeneration and mucosal wave restoration in carbon dioxide laser-ablated canine vocal folds. METHODS: Five beagles underwent stroboscopy before ablation of the left vocal fold with a carbon dioxide laser. Four weeks later, stroboscopy was repeated before and after submucosal injection of hylan B gel into the left vocal fold of 4 animals and of saline solution in 1 animal. Stroboscopy was repeated 12 weeks later, and histologic analysis was performed. RESULTS: Four weeks after laser ablation, all animals had soft tissue defects and absence of mucosal waves. Hylan B injection restored mucosal waves, and saline injection did not. Twelve weeks after injection, hylan B-injected larynges had tissue regeneration and mucosal waves, and the saline-injected larynx had neither. Histology showed regenerated lamina propria with residual foci of hylan B in the hylan B-injected larynges and dense submucosal scar in the saline-injected animal. CONCLUSIONS: Submucosal hylan B gel injection in laser-ablated canine vocal folds restored tissue volume and mucosal waves and facilitated functional tissue regeneration over 12 weeks. Hylan B gel may have utility as a soft tissue scaffold for rehabilitation of phonatory function in vocal folds with lamina propria defects.

Transplanted human multipotent stromal cells reduce acute tongue fibrosis in rats.

BACKGROUND: Tongue fibrosis resulting from head and neck cancer, surgery, radiation, chemotherapy, or a combination thereof devastates one's quality of life. Therapeutic options are limited. Here we investigate human bone marrow-derived multipotent stromal cells (MSC) as a novel injectable treatment for post-injury tongue fibrosis. METHODS: MSCs were grown in culture. Eighteen athymic rats underwent unilateral partial glossectomy. After two weeks for scar formation, a single injection was performed in the tongue scar. Three treatment groups were studied: low and high concentration MSC, and control media injection. Tongues were harvested for evaluation at three weeks post-treatment. RESULTS: Dense fibrosis was achieved in control animals at five weeks. High concentration MSC reduced cross sectional scar burden (P = .007) and pathologic score for inflammation and fibrosis. CONCLUSION: This study establishes the feasibility of a novel rodent tongue fibrosis model, and begins to assess the utility of human MSCs to reduce scar burden. LEVEL OF EVIDENCE: N/a.

Consensus-Based Attributes for Identifying Patients With Spasmodic Dysphonia and Other Voice Disorders.

Importance: A roadblock for research on adductor spasmodic dysphonia (ADSD), abductor SD (ABSD), voice tremor (VT), and muscular tension dysphonia (MTD) is the lack of criteria for selecting patients with these disorders. Objective: To determine the agreement among experts not using standard guidelines to classify patients with ABSD, ADSD, VT, and MTD, and develop expert consensus attributes for classifying patients for research. Design, Setting and Participants: From 2011 to 2016, a multicenter observational study examined agreement among blinded experts when classifying patients with ADSD, ABSD, VT or MTD (first study). Subsequently, a 4-stage Delphi method study used reiterative stages of review by an expert panel and 46 community experts to develop consensus on attributes to be used for classifying patients with the 4 disorders (second study). The study used a convenience sample of 178 patients clinically diagnosed with ADSD, ABSD, VT MTD, vocal fold paresis/paralysis, psychogenic voice disorders, or hypophonia secondary to Parkinson disease. Participants were aged 18 years or older, without laryngeal structural disease or surgery for ADSD and underwent speech and nasolaryngoscopy video recordings following a standard protocol. Exposures: Speech and nasolaryngoscopy video recordings following a standard protocol. Main Outcomes and Measures: Specialists at 4 sites classified 178 patients into 11 categories. Four international experts independently classified 75 patients using the same categories without guidelines after viewing speech and nasolaryngoscopy video recordings. Each member from the 4 sites also classified 50 patients from other sites after viewing video clips of voice/laryngeal tasks. Interrater κ less than 0.40 indicated poor classification agreement among rater pairs and across recruiting sites. Consequently, a Delphi panel of 13 experts identified and ranked speech and laryngeal movement attributes for classifying ADSD, ABSD, VT, and MTD, which were reviewed by 46 community specialists. Based on the median attribute rankings, a final attribute list was created for each disorder. Results: When classifying patients without guidelines, raters differed in their classification distributions (likelihood ratio, χ2 = 107.66), had poor interrater agreement, and poor agreement with site categories. For 11 categories, the highest agreement was 34%, with no κ values greater than 0.26. In external rater pairs, the highest κ was 0.23 and the highest agreement was 38.5%. Using 6 categories, the highest percent agreement was 73.3% and the highest κ was 0.40. The Delphi method yielded 18 attributes for classifying disorders from speech and nasolaryngoscopic examinations. Conclusions and Relevance: Specialists without guidelines had poor agreement when classifying patients for research, leading to a Delphi-based development of the Spasmodic Dysphonia Attributes Inventory for classifying patients with ADSD, ABSD, VT, and MTD for research.

Safety of percutaneous injection of bovine dermal crosslinked collagen for glottic insufficiency.

OBJECTIVE: Our aim was to review the safety of percutaneous injection laryngoplasty using bovine crosslinked collagen, focusing specifically on two often-stated concerns: injecting patients who are taking the anticoagulant medication warfarin, and injecting patients without prior skin hypersensitivity testing. STUDY DESIGN AND SETTING: Retrospective chart review of injection laryngoplasty performed between 1997 and 2006 at the University of California, Los Angeles. RESULTS: The study group consisted of 895 patients who underwent 1290 injection laryngoplasty procedures. No bleeding complications were noted in 59 patients taking warfarin. No allergic complications were reported in 845 patients who did not undergo skin hypersensitivity testing before injection laryngoplasty. CONCLUSION: Percutaneous bovine crosslinked collagen injection laryngoplasty is safe in patients taking warfarin. Skin testing for hypersensitivity does not appear to be necessary before injection. SIGNIFICANCE: Patients on warfarin are candidates for injection laryngoplasty without the need to discontinue the medication. Eliminating skin hypersensitivity testing before percutaneous bovine crosslinked collagen injection laryngoplasty allows for a prompt treatment of glottic insufficiency.

Videostroboscopic findings in unilateral superior laryngeal nerve paralysis and paresis.

OBJECTIVES: Our aim was to present laryngovideostroboscopic findings in unilateral superior laryngeal nerve paresis and paralysis. STUDY DESIGN AND SETTING: Retrospective case review, academic voice clinic. METHODS: Blinded retrospective review of videostroboscopic recordings from cases confirmed by laryngeal electromyography. RESULTS: Three cases of unilateral superior laryngeal nerve paresis and paralysis were identified. At rest, there were no common abnormal laryngeal findings. Upon phonation, common findings were ipsilateral vocal fold bowing and shortening, vocal process height asymmetry with the ipsilateral vocal process overriding the normal, and ipsilateral hyperadduction of the false vocal fold. CONCLUSIONS: The common features noted in these cases of laryngeal electromyography-proved uSLNp could be used to make a presumptive diagnosis of this disorder.

Strobokymographic and videostroboscopic analysis of vocal fold motion in unilateral superior laryngeal nerve paralysis.

The clinical diagnosis of superior laryngeal nerve paralysis (SLNp) is infrequently made, because of the heterogeneity of clinical presentations and laryngoscopic findings. Laryngeal electromyography (LEMG) can provide the definitive diagnosis of this abnormality. With increasing use of LEMG in clinical practice, this condition is now more frequently appreciated by otolaryngologists. A characteristic, but infrequently reported, videostroboscopic vocal fold motion termed Gegenschlagen ("dashing-against-each-other") has previously been described to occur in unilateral SLNp. We encountered such motion in a clinical case, which we subsequently verified as unilateral SLNp by means of LEMG. This characteristic glottic motion was then verified in an in vivo canine model of phonation after unilateral SLNp. Videostrobokymography was performed to generate kymograms that illustrated this vocal fold motion clearly. Kymograms of both human and canine subjects with SLNp demonstrated an undulating motion of the horizontally shifting glottic space as the medial edges of the vocal folds chased each other 90 degrees out of phase. As one vocal fold mucosal edge was opening, the other was closing, and this repeated motion appeared as vocal folds chasing or dashing against each other. Although not uniformly seen in all cases, this vocal fold motion appears to be unique to SLNp.

Ex vivo perfused larynx model of phonation: preliminary study.

OBJECTIVES: Although excised laryngeal models and physical models of the larynx are important in the study of laryngeal dynamics, they cannot be used to study the influence of neuromuscular contraction on vocal fold vibration, especially with regard to the thyroarytenoid muscle. Our aim was to develop an ex vivo larynx model of phonation, and combine the benefits of the in vivo and excised laryngeal models to the ex vivo situation. METHODS: Three canine larynges were surgically removed and perfused ex vivo with modified Krebs-Henseleit reperfusion solution. The laryngeal nerves were stimulated, and an assessment of neuromuscular viability, phonation, and vocal fold vibration was made. RESULTS: Neuromuscular stimulation, phonation, and experimental manipulation were possible for several hours after the onset of ex vivo perfusion. Repeatable periodic phonation in short bursts was achieved. Perfusion appears critical to maintain ex vivo viability, as adductory force was almost immediately lost upon cessation of ex vivo perfusion. CONCLUSIONS: The ex vivo larynx model has the potential to facilitate the measurement of glottal variables in a neuromuscularly correct model. We propose that the further development of this laryngeal model may be useful in the study of laryngeal dynamics, particularly when invasive measurements, such as that of glottal exit flow, are required.

Endoscopic Management of Subglottic Stenosis.

Importance: Optimal management of subglottic stenosis has not been established. Endoscopic techniques include balloon dilation, radial incisions with carbon dioxide laser or cold knife, and combinations of techniques. Adjunctive measures include mitomycin application and glucocorticoid injection. Objective: To determine whether surgical technique or adjunctive measures are associated with duration between surgical procedures. Design, Setting, and Participants: Adult patients with subglottic stenosis treated endoscopically between 1995-2015 at a quaternary academic medical center were identified. Patients with isolated subglottic (cricotracheal) stenosis 18 years and older were included. Patients with prior open surgical procedures, prior laryngeal surgical procedures, glottic stenosis, or vocal fold paralysis were excluded. Interventions: Patients underwent endoscopic procedures including laser radial incisions, balloon dilation, or both, with some patients receiving topical mitomycin, glucocorticoid injection, or both. Main Outcomes and Measures: Time interval between endoscopic treatments. Results: A total of 101 patients (mean [SD] age, 52.3 [15.9] years; 77.2% female) were included in the analysis, with etiologies including idiopathic (47 [46.5%]), intubation (31 [30.7%]), granulomatosis with polyangiitis (9 [8.9%]), and other autoimmune diseases (6 [5.9%]). Among the 219 operations, both laser and balloon dilation were used in 117 (53.4%), while balloon dilation alone was used in 96 (43.8%) and laser alone in 6 (2.7%). Mitomycin application and steroid injection were used in 144 (65.8%) and 93 (42.5%) cases, respectively. Mitomycin application was associated with improvement in the mean interval to next procedure from 317 to 474 days (absolute difference, 157 days; 95% CI, 15-299 days). Advanced grade of stenosis, dilation technique, and steroid injection did not significantly alter the surgical intervals. Conclusions and Relevance: Endoscopic surgery for subglottic stenosis is a critical aspect of patient management. Neither surgical technique nor grade of stenosis was seen to alter the surgical intervals. Mitomycin application was associated with an extended time interval between endoscopic treatments.

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.