Faculty Bibliography

OBJECTIVES/HYPOTHESIS: Although the primary goal of medialization laryngoplasty is to improve glottic closure, implant placement is also likely to alter the biomechanical properties of the vocal fold (VF). We sought to employ novel, nanoscale technology to quantify these properties following medialization based on the hypothesis that different medialization materials will likely yield differential biomechanical effects. STUDY DESIGN: Ex vivo. METHODS: Nine pig larynges were divided into three groups: control, Silastic (Dow Corning, Midland, Michigan, U.S.A.) block medialization, or Gore-Tex (W.L. Gore & Associates, Newark, Delaware) medialization. Laryngoplasty was performed on excised, intact larynges. The larynges were then bisected in the sagittal plane and each subjected to dynamic nanomechanical analysis (nano-DMA) at nine locations using a 250-mum flat-tip punch and frequency sweep-load profile across the free edge of the VF and inferiorly along the conus elasticus. RESULTS: Silastic block and Gore-Tex implant introduced increased storage and loss moduli. Overall, storage moduli mean (maximum) increased from 38 kilopascals (kPa) (119) to 72 kPa (422) and 129 kPa (978) in control, Gore-Tex, and Silastic implants, respectively. Similarly, loss moduli increased from 13 kPa (43) to 22 kPa (201) and 31 kPa (165), respectively. Moduli values varied widely by location in the Silastic block and Gore-Tex groups. At the free VF edge, mean (maximum) storage moduli were lowest in the Gore-Tex group, 20 kPa (44); compared to control, 34.5 kPa (86); and Silastic, 157.9 kPa (978), with similar loss and complex moduli trends. CONCLUSION: Medialization laryngoplasty altered VF structure biomechanical properties; Silastic and Gore-Tex implants differentially impact these properties. LEVEL OF EVIDENCE: NA. Laryngoscope, 2017.

OBJECTIVES/HYPOTHESIS/OBJECTIVE:Our laboratory and others hypothesized that Smad3 is a principle mediator of the fibrotic phenotype in the vocal folds (VFs), and we further posited that alteration of Smad3 expression through short interfering (si)RNA holds therapeutic promise, yet delivery remains challenging. To address this issue, we employed a novel synthetic oligomer, lipitoid, complexed with siRNA to improve stability and cellular uptake with the goal of increased efficiency of RNA-based therapeutics. STUDY DESIGN/METHODS:In vitro study and in vivo animal model. METHODS:In vitro, lipitoid cytotoxicity was quantified via colorimetric and LIVE/DEAD assays in immortalized human VF fibroblasts and primary rabbit VF fibroblasts. In addition, optimal incubation interval and solution for binding siRNA to lipitoid for intracellular delivery were determined. In vivo, a rabbit model of VF injury was employed to evaluate Smad3 knockdown following locally injected lipitoid-complexed siRNA. RESULTS:In vitro, lipitoid did not confer additional toxicity compared to commercially available reagents. In addition, 20-minute incubation in 1× phosphate-buffered saline resulted in maximal Smad3 knockdown. In vivo, Smad3 expression increased following VF injury. This response was significantly reduced in injured VFs at 4 and 24 hours following injection (P = .035 and .034, respectively). CONCLUSIONS:The current study is the first to demonstrate targeted gene manipulation in the VFs as well as the potential utility of lipitoid for localized delivery of genetic material in vivo. Ideally, these data will serve as a platform for future investigation regarding the functional implications of therapeutic gene manipulation in the VFs. LEVEL OF EVIDENCE/METHODS:NA Laryngoscope, 2017.

OBJECTIVES/HYPOTHESIS: A secure airway is critical to study obstructive disorders of the larynx and trachea in preclinical models. Tracheostomy has been described in rabbits, swine, canines, and other mammals using tracheostomy tubes or permanent stomas. No studies specifically evaluated morbidity and mortality associated with these models, and existing studies using tracheostomy make little mention of tracheostomy-related complications. We assessed the management, complications, and mortality associated with tracheostomy in a rabbit model that has recently gained significant attention. STUDY DESIGN: In vivo. METHODS: Twenty-two female rabbits underwent tubeless tracheotomy. Rabbits were monitored hourly for the first 8 hours, with progressively increasing intervals between evaluations up to 7 days. A suctioning and tracheal moisture protocol was employed, and animals with signs of crusting or impending airway compromise underwent therapeutic bronchoscopy. RESULTS: Nine of 22 (41%) rabbits succumbed to tracheostomy-related complications, ranging from 1 to 7 days after tracheotomy. The experiment consisted of two study groups. The preliminary group of 10 rabbits studied over a 4-day period had 40% mortality. After implementing modified preventive therapy guidelines and a new humidification system, the second group of 12 rabbits studied over a 7-day period had 42% mortality. Average time to unrecoverable complication was 2.2 days (median = 2 days). Cause of death was airway obstruction in four animals and respiratory depression in three animals, and two animals were found unresponsive. CONCLUSION: Tracheostomy in preclinical rabbit models should be temporally limited, and investigators should anticipate tracheostomy-related complications during study design. LEVEL OF EVIDENCE: NA. Laryngoscope, 2017.

OBJECTIVES/HYPOTHESIS: Given that the vocal folds are active organs of respiration, reports of dyspnea in the context of glottic insufficiency are not uncommon. We hypothesize that improved glottal closure via framework surgery or vocal fold augmentation improves dyspnea symptoms. STUDY DESIGN: Retrospective review. METHODS: Charts of patients undergoing procedures to correct glottal insufficiency, either via vocal fold augmentation (VFA) or medialization laryngoplasty (ML) between December 2012 and September 2015 were reviewed (n = 189). Modified Borg Dyspnea Scale (MBDS) and Modified Medical Research Council Dyspnea Scale (MMRCDS) data were collected before and after intervention. Age, body mass index (BMI), and sex, as well as pulmonary and cardiac comorbidities were considered. Subgroup analysis was performed on individuals with subjective dyspnea prior to intervention. RESULTS: For the entire cohort, differences in the MMRCDS and MBDS were not statistically different pre- and postintervention (P = .20 and P = .12, respectively). Patients with BMI <30 experienced more improvement on the MBDS (P = .03). Both the MMRCDS and MMBDS improved post-procedure (P = .001 and P = .001, respectively) in patients reporting dyspnea prior to intervention. CONCLUSIONS: Patients with glottic insufficiency and dyspnea prior to intervention to improve glottic closure had a significant reduction in dyspnea following treatment. Conversely, subjects without complaints of dyspnea prior to intervention had variable outcomes with regard to dyspnea symptoms. Additionally, based on data from the entire cohort, VFA or ML did not worsen dyspnea symptoms. These data may assist in counseling and/or selection of patients considered for procedures to improve glottic closure. LEVEL OF EVIDENCE: 4 Laryngoscope, 2017.

OBJECTIVES/HYPOTHESIS: To describe the distribution of recurrent respiratory papillomatosis (RRP) lesions across 21 laryngeal anatomic regions in previously untreated patients at initial presentation to provide insight regarding the natural history of RRP. STUDY DESIGN: Multi-institutional, retrospective case series. METHODS: Initial laryngoscopic examination videos of 83 previously untreated patients with adult-onset RRP were reviewed. Papilloma locations were recorded using a 21-region laryngeal schematic. Multivariate analyses by anatomic subsite were conducted for the entire population and for subgroups stratified by sex, age, and proton pump inhibitor (PPI) usage. Heat maps were generated, hierarchically color coding the anatomic distribution of disease. RESULTS: In this cohort, RRP was most likely to occur on the true vocal folds (TVFs) and anterior commissure (P < .0001, odds ratio [OR]: 7.02); within the TVFs, the membranous vocal folds (MVFs) were most likely to be affected (P < .0001, OR: 3.56). The cohort was predominantly male (80.7%); males had a higher average number of affected sites (P = .005) and were more likely to have lesions in any laryngeal subsite (P < .0001, OR: 2.88,) compared to females. PPI users were more likely than nonusers to have disease in any laryngeal subsite (P = .0037, OR: 1.62), particularly in the posterior and subglottic regions (P = .0061, OR: 2.53). Age was not correlated with lesion prevalence or distribution. CONCLUSIONS: In untreated patients presenting to three laryngology clinics, the MVFs were most likely to be affected by RRP. Males had more anatomic sites affected by papilloma than females. The influence of PPI use on RRP distribution warrants further investigation. LEVEL OF EVIDENCE: 4. Laryngoscope, 2017.

Importance/UNASSIGNED:Compromised cough effectiveness is correlated with dysphagia and aspiration. Glottic insufficiency likely yields decreased cough strength and effectiveness. Although vocal fold augmentation favorably affects voice and likely improves cough strength, few data exist to support this hypothesis. Objective/UNASSIGNED:To assess whether vocal fold augmentation improves peak airflow measurements during maximal-effort cough following augmentation. Design, Setting, and Participants/UNASSIGNED:This case series study was conducted in a tertiary, academic laryngology clinic. Participants included 14 consecutive individuals with glottic insufficiency due to vocal fold paralysis, which was diagnosed via videostrobolaryngoscopy as a component of routine clinical examination. All participants who chose to proceed with augmentation were considered for the study whether office-based or operative augmentation was planned. Postaugmentation data were collected only at the first follow-up visit, which was targeted for 14 days after augmentation but varied on the basis of participant availability. Data were collected from June 5, 2014, to October 1, 2015. Data analysis took place between October 2, 2015, and March 3, 2017. Main Outcomes and Measures/UNASSIGNED:Peak airflow during maximal volitional cough was quantified before and after vocal fold augmentation. Participants performed maximal coughs, and peak expiratory flow during the maximal cough was captured according to American Thoracic Society guidelines. Results/UNASSIGNED:Among the 14 participants (7 men and 7 women), the mean (SD) age was 62 (18) years. Three types of injectable material were used for vocal fold augmentation: carboxymethylcellulose in 5 patients, hyaluronic acid in 5, and calcium hydroxylapatite in 4. Following augmentation, cough strength increased in 11 participants and decreased cough strength was observed in 3. Peak airflow measurements during maximal cough varied from a decrease of 40 L/min to an increase of 150 L/min following augmentation. When preaugmentation and postaugmentation peak airflow measurements were compared, the median improvement was 50 L/min (95% CI, 10-75 L/min; P = .01). Immediate peak airflow measurements during cough collected within 30 minutes of augmentation varied when compared with measurements collected at follow-up (103-380 vs 160-390 L/min). Conclusions and Relevance/UNASSIGNED:Peak airflow during maximal cough may improve with vocal fold augmentation. Additional assessment and measurements are needed to further delineate which patients will benefit most regarding their cough from vocal fold augmentation.

OBJECTIVE: Recent reports highlight the efficacy of small interfering RNA (siRNA) targeting SMAD3 to regulate transforming growth factor beta (TGF-beta)-mediated fibroplasia in vocal fold fibroblasts. The current study sought to investigate SMAD3 expression during wound healing in vivo and quantify the downstream transcriptional events associated with SMAD3 knockdown in vitro. STUDY DESIGN: In vivo and in vitro. METHODS: Unilateral vocal fold injury was created in a rabbit model. SMAD3 and SMAD7 mRNA expression was quantified at 1 hour and 1, 3, 7, 14, 30, 60, and 90 days following injury. In vitro, multi-gene analysis technology was employed in our immortalized human vocal-fold fibroblast cell line following TGF-beta1 stimulation +/- SMAD3 knockdown across time points. RESULTS: SMAD3 mRNA expression increased following injury; upregulation was significant at 3 and 7 days compared to control (both P < 0.001). SMAD7 mRNA was also upregulated at 3, 7, and 14 days (P = 0.02, P < 0.001, and P < 0.001, respectively). In vitro, SMAD3 knockdown reduced the expression of multiple profibrotic, TGF-beta signaling, and extracellular matrix metabolism genes at 6 and 24 hours following TGF-beta1 stimulation. CONCLUSION: Cumulatively, these data support SMAD3 as a potential master regulator of TGF-beta-mediated fibrosis. SMAD3 transcription peaked 7 days following injury. Multi-gene analysis indicated that the therapeutic effectiveness of SMAD3 knockdown may be related to regulation of downstream mediators of fibroplasia and altered TGF-beta signaling. LEVEL OF EVIDENCE: NA. Laryngoscope, 2017.

OBJECTIVES: This study aims (1) to present a case of asystole during direct laryngoscopy in an otherwise healthy patient at an outpatient surgery center and (2) to review literature on cardiac complications, specifically asystole and bradycardia, during direct laryngoscopy. METHODS: A 67-year-old woman with no prior cardiac history underwent induction with succinylcholine and remifentanil for direct laryngoscopy and vocal fold augmentation. During suspension laryngoscopy, the patient became asystolic, and advanced care life support measures were started. The patient regained a cardiac rhythm after chest compressions and epinephrine and was transferred to a tertiary care hospital for further treatment. She remained intubated overnight, requiring pressors, and regained normal cardiac function over the next few days. RESULTS: A structured literature review uncovered few reports of asystole during suspension laryngoscopy. Although bradycardia is common during suspension laryngoscopy, likely secondary to stimulation of afferent visceral sensory parasympathetic fibers of the vagus nerve, asystole is rare. CONCLUSIONS: Cardiac complications are possible in otolaryngologic surgery, especially with activation of the oculocardiac or trigeminocardiac reflexes. Asystole during direct laryngoscopy, although rare, is not always predictable from medicine or cardiac risk indices. Awareness, rapid recognition, and early implementation of advanced care life support are crucial to avoid further complications.

This study employs validated cough assessment tools to prospectively determine the impact of tramadol on cough severity and quality of life in subjects with neurogenic cough. The study was a prospective case series with planned data collection at a tertiary care academic medical center laryngology practice. Sixteen consecutive collected subjects with neurogenic cough prospectively completed pre- and posttreatment validated cough assessment tools, the cough severity index (CSI) and Leicester Cough Questionnaire (LCQ). All subjects in the study reported at least some improvement in their cough symptoms. In a Wilcoxon signed rank test that compared paired results, CSI scores improved from 23 to 14 and LCQ scores improved from 74 to 103 ( P = .003 and P = .005, respectively). This small preliminary assessment suggests that tramadol warrants additional evaluation as a treatment for neurogenic cough.

OBJECTIVES/HYPOTHESIS: Quantification of clinical outcomes after vocal fold (VF) interventions is challenging with current technology. High-speed digital imaging and optical coherence tomography (OCT) of excised larynges assess intact laryngeal function, but do not provide critical biomechanical information. We developed a protocol to quantify tissue properties in intact, excised VFs using dynamic nanomechanical analysis (nano-DMA) to obtain precise biomechanical properties in the micrometer scale. STUDY DESIGN: Experimental animal study. METHODS: Three pig larynges were bisected in the sagittal plane, maintaining an intact anterior commissure, and subjected to nano-DMA at nine locations with a 250-mum flat-tip punch and frequency sweep load profile (10-105 Hz, 1,000 muN peak force) across the free edge of the VF and inferiorly along the conus elasticus. RESULTS: Storage, loss, and complex moduli increased inferiorly from the free edge. Storage moduli increased from a mean of 32.3 kPa (range, 6.5-55.38 kPa) at the free edge to 46.3kPa (range, 7.4-71.6) 5 mm below the free edge, and 71.4 kPa (range, 33.7-112 kPa) 1 cm below the free edge. Comparable values were 11.6 kPa (range, 5.0-20.0 kPa), 16.7 kPa (range, 5.7-26.8 kPa), and 22.6 kPa (range, 9.7-38.0 kPa) for loss modulus, and 35.7 kPa (range, 14.4-56.4 kPa), 50.1 kPa (range, 18.7-72.8 kPa), and 75.4 kPa (range, 42.0-116.0 kPa) for complex modulus. Another larynx repeatedly frozen and thawed during technique development had similarly increased storage, loss, and complex modulus trends across locations. CONCLUSIONS: Nano-DMA of the intact hemilarynx provides a platform for quantification of biomechanical responses to a myriad of therapeutic interventions to complement data from high-speed imaging and OCT. LEVEL OF EVIDENCE: NA Laryngoscope, 2016.