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Objective: Studies showed that photodynamic therapy (PDT) might be able to prevent vocal fold scar formation when treating laryngeal lesions. We aim to investigate if PDT improves vocal wound healing and reduces scar formation in both prophylactic and remodeling procedures performed in vivo. Study Design: In vivo. Methods: Vocal fold stripping was performed in Sprague–Dawley rats. PDT was performed with intraperitoneal injection of 100 mg/kg 5‐Aminolevulinic Acid (5‐ALA) and 635 nm laser irradiation of 20, 40, and 60 J/cm2. PDT was performed immediately after surgery to study the prophylactic effect and 4 weeks after surgery to study the remodeling effect. Gene expression was evaluated with real‐time PCR at 1 week after PDT. Histologic evaluations were performed 12 weeks after PDT, including hematoxylin–eosin, Masson, Alcian blue staining, and immunohistochemical staining of collagen I and III. Results: PDT induced similar effects on the vocal fold wound healing outcomes in both prophylactic and remodeling procedures. Expression of MMP8, MMP13, HAS2, and TGFβ1 was significantly elevated. Histologic evaluation revealed significantly increased thickness, decreased density of collagen, and increased deposition of hyaluronic acid in the lamina propria. Immunohistochemistry also revealed better distribution and reduced density of collagen I and III. The most obvious changes were seen in the 60 J/cm2 PDT group. Conclusion: PDT could significantly improve vocal wound healing by providing both prophylactic effects and remodeling effects. It may be a minimally invasive treatment for vocal fold lesions with slight vocal scarring, and may be used to treat acute or chronic vocal injury to reduce vocal scarring. Level of Evidence: N/A Laryngoscope, 133:1943–1951, 2023 [ABSTRACT FROM AUTHOR]

Objective: To evaluate the concept and efficacy of an adjustable implant (Prototype SH30: porcine implant and APrevent® VOIS: human concept) for treatment of unilateral vocal fold paralysis (UVFP) via in vivo mini‐pig studies, human computed tomographic (CT) and magnetic resonance (MR) image analysis, ex‐vivo aerodynamic and acoustic analysis. Methods: Feasibility testing and prototype implantation were performed using in‐vivo UVFP porcine model (n = 8), followed by a dimensional finding study using CT and MR scans of larynges (n = 75) for modification of the implant prototypes. Acoustic and aerodynamic measurements were recorded on excised canine (n = 7) larynges with simulated UVFP before and after medialization with VOIS‐Implant. Results: The prototype showed in the in‐vivo UVFP porcine model an improved glottic closure from grade 6 incomplete closure to complete closure (n = 5), to grade 2 incomplete closure (n = 2) and grade 3 incomplete closure (n = 1). On human CT/MR scans the identification of the correct size was successful in 97.3% using the thyroid cartilage alar "distance S" as the only parameter, which is an important step towards procedure standardization and implant design. Results were confirmed with implantation in human laryngeal cadavers (n = 44). Measurements of the acoustic and aerodynamic effects after implantation showed a significant decreased phonation threshold pressure (p =.0187), phonation threshold flow (p =.0001) and phonation threshold power (p =.0046) on excised canine larynges with simulated UVFP. Percent jitter and percent shimmer decreased (p =.2976; p =.1771) but not significant. Conclusions: Based on the preclinical results four sizes, differing in medial length, implant width and expansion direction of silicone cushions, seem to be enough to satisfy laryngeal size variations. This concept is significantly effective in medializing UVFP and improving the aerodynamic and acoustic qualities of phonation as reported in a preliminary clinical outcome study with long‐term implantation. Level of Evidence: N/A [ABSTRACT FROM AUTHOR]

Objective: Little is known about the efficacy of using artificial intelligence (AI) to identify laryngeal carcinoma from images of vocal lesions taken in different hospitals with multiple laryngoscope systems. This multicentre study aimed to establish an AI system and provide a reliable auxiliary tool to screen for laryngeal carcinoma. Study design: Multicentre case–control study. Setting: Six tertiary care centres. Participants: Laryngoscopy images were collected from 2179 patients with vocal fold lesions. Outcome measures: An automatic detection system of laryngeal carcinoma was established and used to distinguish malignant and benign vocal lesions in 2179 laryngoscopy images acquired from 6 hospitals with 5 types of laryngoscopy systems. Pathological examination was the gold standard for identifying malignant and benign vocal lesions. Results: Out of 89 cases in the malignant group, the classifier was able to correctly identify laryngeal carcinoma in 66 patients (74.16%, sensitivity). Out of 640 cases in the benign group, the classifier was able to accurately assess the laryngeal lesion in 503 cases (78.59%, specificity). Furthermore, the region‐based convolutional neural network (R‐CNN) classifier achieved an overall accuracy of 78.05%, with a 95.63% negative predictive value and a 32.51% positive predictive value for the testing data set. Conclusion: This automatic diagnostic system has the potential to assist clinical laryngeal carcinoma diagnosis which may improve and standardise the diagnostic capacity of laryngologists using different laryngoscopes. [ABSTRACT FROM AUTHOR]

Objectives: The compound betamethasone is widely used to prevent scarring in dermatology. This study aims to explore the effects of compound betamethasone on vocal fold (VF) wound healing. Study design: Prospective animal study in rabbits. Methods: Eighteen rabbits underwent bilateral VF stripping and three rabbits served as controls. 0.1 mL of compound betamethasone (1 mL: betamethasone sodium phosphate 5 mg and betamethasone dipropionate 2 mg) was injected into the right VF of each rabbit, and 0.1 mL 0.9% saline was injected into the contralateral VF. Endoscopy was performed for morphologic observation. Six larynges were harvested for histological analysis at 3 days, 7 days, and 1 month. The VFs were stained with hematoxylin and eosin (H&E), Alcian blue, and Masson' trichrome staining. Results: In morphological analysis, there was no visible difference between betamethasone‐treated and saline‐treated VFs at 3 and 7 days. After 1 month, more VF scars appeared on the saline‐treated VFs than the VFs treated with betamethasone. Inflammatory cell number showed significant difference between both VFs at 3 days (p =.037) and 7 days (p =.045). No significant different was found in epithelial thickness at 1 month between the betamethasone and saline groups. The collagen in the saline‐treated VFs was significantly denser than that of the betamethasone‐treated group (p =.037). There was also a significant increase in the level of hyaluronic acid (HA) in betamethasone‐injected VFs in comparison to the saline‐injected VFs (p =.006). Conclusions: Based on this study, compound betamethasone can improve VF healing. Our findings suggest that VF injection with compound betamethasone helps to minimize scarring by increasing HA level and decreasing collagen density. [ABSTRACT FROM AUTHOR]

Objective: Photodynamic therapy (PDT) is a minimally invasive method with strong tissue selectivity and nonthermal effects. We aim to investigate the efficacy of an in‐office method utilizing PDT with local application of 5‐aminolevulinic acid (ALA) and 635 nm diode laser for treating laryngeal leukoplakia. Study Design: Retrospective cohort study. Setting: Outpatient clinic‐tertiary medical center. Methods: This study reviewed 32 patients with laryngeal leukoplakia, including 11 recurrent cases after surgery. All the procedures were performed in an office setting under topical anesthesia. Fifteen percent ALA solution was locally applied to the lesion through a flexible laryngoscope. Light illumination was performed using a 635 nm diode laser through a 400 μm optic fiber. The power density was 165 mW/cm2 to reach 100 J/cm2. Results of laryngostroboscopy and voice evaluation during follow‐up were collected. Results: The mean follow‐up was 7.91 ± 4.83 (3‐18) months. Thirty‐nine procedures were performed, including 1 session for 27 patients, 2 sessions for 3 patients, and 3 sessions for 2 patients. The total response rate was 96.875% (31/32), including complete responses in 26 (81.25%) patients, partial responses in 5 patients (15.625%), and no response in 1 patient (3.125%). It appeared that PDT selectively eliminated the leukoplakia without affecting lamina propria and the surrounding normal mucosa remained unharmed. Scores of Voice Handicap Index‐10, jitter, shimmer, and harmonic‐to‐noise ratio were significantly improved after PDT. Conclusion: Office‐based PDT is an effective, repeatable, and practical method for treating laryngeal leukoplakia. Local application of ALA is sufficient to achieve photodynamic reactions. PDT could eliminate laryngeal leukoplakia selectively while protecting the normal laryngeal structure. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Vocal fold (VF) fibroblasts are the central target for developing new strategies for the treatment of VF scarring and fibrosis. Asiatic acid (AA) is a triterpenoid derivate with antifibrotic properties. However, the effect of AA in VF scarring is poorly understood. The objective of this study was to investigate the potential application of AA as a therapeutic treatment in VF scarring. Study Design: Xxxxx. Methods: The functional expression of SMAD7 was knocked down with recombinant adenoviruses and adeno‐associated viruses carrying shRNAs in the in vitro and in vivo models, which were constructed to investigate AA's antifibrotic function. The expression of collagens and SMADs in cultured human and rabbit cell lines and animal models was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry labeling, respectively. Cell migration capacity and contraction in VF fibroblast cell lines were also evaluated. Results: AA downregulated the downstream fibrotic activation in a dose‐dependent manner. Meanwhile, AA attenuated VF scarring/fibrosis by reducing collagen deposition. Furthermore, the antifibrotic effects of AA were associated with the upregulation of SMAD7. In contrast, knockdown of SMAD7 inhibited the effect of AA on transforming growth factor‐beta‐1 (TGF‐β1) stimulation, which suggests a central role for SMAD7 in AA‐induced antifibrotic activities during VF fibrosis. Conclusion: We concluded that AA, which is a novel therapeutic candidate for preventing VF scarring/fibrosis, might exert its antifibrotic effect via the TGF‐β1/SMAD signaling pathway. Level of Evidence: NA Laryngoscope, 132:1237–1244, 2022 [ABSTRACT FROM AUTHOR]

Background: Pharyngeal high‐resolution manometry (HRM) has emerged over the last decade as a valuable assessment tool for oropharyngeal dysphagia. Data analysis thus far has focused primarily on measures of pressure and duration within key anatomic regions. We apply spectral arc length (SPARC), a dimensionless metric for quantifying smoothness felt to indirectly reflect neuromuscular coordination, as a new method of describing manometric curves. We then use it to distinguish swallows from healthy subjects and those with dysphagia related to stroke. Methods: Previously collected pharyngeal HRM data from eight subjects with history of stroke and eight age‐ and sex‐matched controls were reviewed. Receiver operating characteristic (ROC) analysis was used to optimize SPARC inputs. SPARC was then computed for the velopharynx, tongue base, hypopharynx, and upper esophageal sphincter (UES), and the values were compared between the two subject groups. Results: Optimized parameter settings yielded an ROC curve with area under the curve (AUC) of 0.953. Mean SPARC values differed between control and stroke subjects for the velopharynx (t = 3.25, p = 0.0058), tongue base (t = 4.77, p = 0.0003), and hypopharynx (t = 2.87, p = 0.0124). Values were similar for the UES (t = 0.43, p = 0.671). Conclusions: In this preliminary study, SPARC analysis was applied to distinguish control from post‐stroke subjects. Considering alternative methods of analyzing pharyngeal HRM data may provide additional insight into the pathophysiology of dysphagia beyond what can be gleaned from measures of pressure and duration alone. [ABSTRACT FROM AUTHOR]

Objective: To explore biomarkers that are candidates for understanding potential degeneration to malignancy of vocal fold leukoplakia (VFL), with the goal of guiding future diagnostic and treatment recommendations.Data Sources: PubMed and Medline search engines.Review Methods: A systematic review was conducted by searching the following key words: vocal fold or laryngeal, coupled with leukoplakia or dysplasia, and combined with the term prognostic markers. We collated the biomarkers and their significance, followed by observing the power of their evidence by assessing the quality of the studies according to guidelines of tumor marker prognostic studies (REMARK).Conclusions: Prognostic biomarkers in the 16 studies are generally divided into 3 categories according to their biological roles: proliferation (Ki-67, CK-1 RS14024 SNP), cell cycle control (P53, p16, cyclin D1, p57kip2, interleukin-10 [IL-10], miR-10a, and miR-34c), cell adhesion, and invasion (neutrophil-to-lymphocyte ratio, OPN/CD44v6 axis, MMP-1, vascular endothelial growth factor A, MMP-9, serpin peptidase inhibitor 1, plasminogen activator, CTNN/B1, β-catenin, NANOG, HERG1). The prognostic use of these biomarkers is limited due to the variable methodologies, study design, assay methods, and statistical analysis performed.Implications For Practice: Prognostic factors in vocal fold leukoplakia have important clinical implications regarding the potential for malignant degeneration. Although further study is needed, the currently available evidence suggests that p53, p16, cyclin D1, IL-10, NLR, OPN and CD44v6, CTNNB1, and CTTN and FAK might be of particular interest in determining prognosis of VFL as related to malignancy. Future, large, well-designed, prospective studies are expected to determine the prognostic power of these biomarkers before their implementation in routine clinical practice. [ABSTRACT FROM AUTHOR]

Objectives: Straw phonation has been investigated for its vocal warm-up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue.Study Design: Prospective cohort study METHODS: Twenty-five healthy participants were recruited into 1-hour vocal loading tasks followed by 10-minute vocal rest or straw phonation on 2 different days. Various parameters including phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention.Results: Increased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw phonation. More significant improvements were obtained in straw phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw phonation when compared to vocal rest.Conclusions: Straw phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands.Level Of Evidence: 4 Laryngoscope, 130:E674-E679, 2020. [ABSTRACT FROM AUTHOR]

Objective: To investigate the feasibility of dynamic computed tomography in recording and describing the spatial motion characteristics of the arytenoid cartilage.Methods: Dynamic computed tomography recorded the real-time motion trajectory of the arytenoid cartilage during inspiration and phonation. A stationary coordinate system was established with the cricoid cartilage as a reference and a motion coordinate system was established using the movement of the arytenoid cartilage. The Euler angles of the arytenoid cartilage movement were calculated by transformation of the two coordinate systems, and the spatial motion characteristics of the arytenoid cartilage were quantitatively studied.Results: Displacement of the cricoid cartilage was primarily inferior during inspiration. During phonation, the displacement was mainly superior. When the glottis closed, the superior displacement was about 5-8 mm within 0.56 s. During inspiration, the arytenoid cartilage was displaced superiorly approximately 1-2 mm each 0.56 s. The rotation angle was subtle with slight rotation around the XYZ axis, with a range of 5-10 degrees. During phonation, the displacement of the arytenoid cartilage was mainly inferior (about 4-6 mm), anterior (about 2-4 mm) and medial (about 1-2 mm). The motion of the arytenoid cartilage mainly consisted of medial rolling, and there was an alternating movement of anterior-posterior tilting. The arytenoid cartilage rolled medially (about 20-40 degrees within 0.56 s), accompanied by anterior-posterior tilting (about 15-20 degrees within 0.56 s).Conclusion: Dynamic computed tomography recordings of arytenoid cartilage movement can be combined with Euler transformations as a tool to study the spatial characteristics of laryngeal structures during phonation.Level Of Evidence: 4 Laryngoscope, 130:E646-E653, 2020. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Vocal fold collagen composition is an important determinant of material properties and mucosal wave propagation. Collagen alignment and straightness are quantitatively characterized by second harmonic generation (SHG) imaging. We examined leporine, canined and porcine vocal folds showing collagen composition variation that is species, location, and strain specific.Study Design: Animal model.Methods: Leporine (n = 5), canine (n = 5), and porcine (n = 5) larynges were harvested and fixed in situ. Samples were transversely sectioned, and SHG images were collected for two inferior-superior sections along five anterior-posterior locations. Additional porcine samples were fixed and imaged under tensile strain (0%, 5%, 10%, 15%, 20%, n = 5 per group). Two-way repeated measures (RM) analysis of variance (ANOVA) tested for section and location differences in each species. Multiway RM-ANOVA tested for section, location, and strain differences in porcine samples.Results: Alignment and straightness were higher inferiorly in the porcine (P = .0047, P = .002) and canine (P = .0011, P < .001) vocal folds, but not in leporine samples (P = .67652, P = .4831). There were significant interactions between elongation and superior-inferior section for both alignment (P = .0047) and straightness (P = .0371).Conclusions: Our results correspond well to findings in the literature that the inferior vocal fold lip is stiffer in porcine and canine larynges. The absence of a collagen gradient in the leporine vocal fold is notable because rabbits are less vocal animals, indicating the collagen gradient may be a result of voice use and an important consideration in model selection when extracellular matrix is of interest. Strain results were also consistent with the role of collagen in strain stiffening behavior of vocal fold tissue.Level Of Evidence: NA Laryngoscope, 129:2549-2556, 2019. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Phonation threshold pressure (PTP), the minimum subglottal pressure (Ps ) required for phonation, is sensitive to changes in laryngeal biomechanics and is often elevated with pathology. Little is reported on PTP in children; challenges with task performance and measurement reliability represent barriers to routine clinical assessment.Study Design: Pilot study evaluating PTP and Ps measurement reliability in children using labial and mechanical interruption.Methods: Twenty-two subjects aged 4 to 17 years (10.7 ± 3.9 years) participated. Ten trials were performed for each method; task order was randomized. For labial interruption, subjects produced /pα/ five times at softest (onset PTP) and comfortable amplitude. For mechanical interruption, subjects produced a sustained /α/ while a balloon valve interrupted phonation five times for 250 ms each; mechanical interruption was performed with a mouthpiece and mask. PTP was recorded as the difference between Ps and supraglottal pressure at phonation cessation (offset PTP). Mean PTP and Ps and intrasubject coefficients of variation were compared. Correlations with age were evaluated.Results: Mean PTP (P < .001) and Ps (P = .005) were higher for labial interruption. Intrasubject coefficients of variation for PTP (P = .554) and Ps (P = .305) were similar across methods. Coefficient of variation was related to age for mechanical-mask trials only (r = -0.628, P = .00175).Conclusions: Differences in means are likely related to differences in task and PTP hysteresis effect. Reliability is comparable with all methods; using a mouthpiece may be preferable to a mask for mechanical interruption. Measurement of PTP is noninvasive, reliable, and may be a useful adjunct in pediatric voice assessment.Level Of Evidence: 3b Laryngoscope, 129:1520-1526, 2019. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Vocal fold scarring remains a major treatment challenge, and scar prevention without residual lesions remains a dilemma. Cryotherapy has shown cosmetic outcomes on skin lesions with minimal scarring. The aim of this study was to clarify the beneficial effects of cryotherapy for the prevention and the treatment of vocal fold scarring.Study Design: In vitro.Methods: Primary cultures of human vocal fold fibroblasts (VFFs) were used in this study. Myofibroblast differentiation was stimulated by transforming growth factor β1 (TGF-β1). We mimicked the cryotherapy effect on vocal fold healing in vivo by freezing VFFs ± TGF-β1 in vitro. The influence of freezing on cell viability, proliferation, migration, and contractile properties were analyzed. The expression of collagen I, collagen III, fibronectin, TGF-β1, matrix metallopeptidase 1 (MMP1), hyaluronan synthase 1 (HAS1) were investigated by real-time polymerase chain reaction (RT-PCR), and the expression of alpha smooth muscle actin (α-SMA) and decorin were investigated by RT-PCR and Western blot.Results: Freezing was found to modify extracellular matrix (ECM) synthesis and differentiation of VFFs. Expression of collagen I, collagen III, fibronectin, α-SMA, and TGF-β1 was downregulated, and MMP1 was upregulated in VFFs + TGF-β1 (myofibroblast) by freezing. HAS1 and decorin were upregulated in both VFFs ± TGF-β1 by freezing. Freezing VFFs + TGF-β1 (myofibroblast) with fast thawing had a lower expression of α-SMA when compared with slow thawing. Freezing reduced the migration and collagen contraction of VFFs + TGF-β1 (myofibroblast).Conclusion: Cryotherapy induces antifibrotic and regenerative ECM alterations in VFFs. These data provide insight into the prevention and the treatment of vocal fold scarring with cryotherapy in phonomicrosurgery.Level Of Evidence: NA Laryngoscope, 129:E143-E150, 2019. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Cryotherapy has been shown to be a scarless treatment modality for dermal lesions; however, there are limited data addressing the effect of cryotherapy on vocal fold tissue. The aim of this study was to clarify the effectiveness of cryotherapy for prevention of postsurgical vocal fold scarring.Study Design: Prospective animal study in rabbits.Methods: The lamina propria of 20 rabbit vocal folds was bilaterally stripped, followed by randomized unilateral cryotherapy. Five larynges were harvested for real-time polymerase chain reaction (RT-PCR) analysis at 1 day, 3 days, and 7 days postinjury. The remaining five were harvested for histologic analysis at 3 months. Images of the healing phase were recorded by laryngoscopy. Analyses of RT-PCR for cyclooxygenase (COX)-2, interleukin (IL)-6, collagen I, collagen III, matrix metallopeptidase 1 (MMP1), transforming growth factor β (TGFβ1), α smooth muscle actin (α-SMA), and hyaluronan synthase 1 (HAS1) were completed. Histological samples were completed for collagen and hyaluronic acid analysis.Results: RT-PCR results revealed that higher expressions of HAS1 and MMP1 and lower expressions of COX-2, IL-6, collagen I, collagen III, TGFβ1, and α-SMA were observed, and histological examination showed significantly increased hyaluronic acid, decreased deposition, and more organized configuration of collagen in injury with the cryotherapy cohort compared with the injury cohort.Conclusions: Cryotherapy can inhibit the inflammatory reaction and simulate a fetal healing environment in extracellular matrix synthesis to regenerate vocal fold tissue with less fibrosis. Histological results showed that cryotherapy achieves a mature healing result with less scar, which tends to return to normal. In summary, the findings of this study suggest that administration of cryotherapy at the time of injury has the potential to minimize vocal fold scarring.Level Of Evidence: NA Laryngoscope, 129:E151-E157, 2019. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the feasibility of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) for vocal fold leukoplakia.Study Design: Ex vivo and in vivo.Methods: 5-ALA was applied topically as a 20% solution to ex vivo canine vocal folds. The penetration depth and concentrations of 5-ALA in tissue were quantified using frozen sectioning and fluorescamine derivatization after 5-ALA contact incubation or topical spraying. Then, 5-ALA solution was sprayed on leporine vocal folds once, twice, or given systemically in vivo. Protoporphyrin IX (PPIX) location was visualized using fluorescence microscopy, and PPIX concentrations were measured using a fluorescent quantitative method. Hematoxylin and eosin (H&E) staining was performed to visualize the histological changes of vocal folds after PDT for each group.Results: Topical incubation of 15 minutes with 5-ALA achieved a penetration depth of over 2 mm and similar concentrations within the superficial 500 μm of epithelium, compared with longer incubation times. Topical spraying of 5-ALA produced sufficient concentrations in vocal folds, but the retention time is short. An in vivo leporine model showed that laryngeal spraying of 20% 5-ALA induced similar penetration depth and concentrations of PPIX compared to systemic administration of 5-ALA. Two sprays of 20% 5-ALA solution with an interval of 30 minutes are needed to produce complete exfoliation of vocal fold epithelium.Conclusion: Topical PDT with laryngeal spraying of 20% 5-ALA solution achieves sufficient therapeutic effects and is potentially applicable for the treatment of vocal fold leukoplakia.Level Of Evidence: NA Laryngoscope, 129:E80-E86, 2019. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Photodynamic therapy (PDT) is a promising treatment modality for laryngeal dysplasia, early-stage carcinoma, and papilloma, and was reported to have the ability to preserve laryngeal function and voice quality without clinical fibrotic response. We aimed to investigate the mechanism behind the antifibrotic effects of PDT on primary human vocal fold fibroblasts (VFFs) in vitro.Study Design: In vitro analysis from one human donor.Methods: Cell viability of VFFs in response to varying doses of PDT was investigated by the Cell Counting Kit-8 method. Sublethal-dose PDT (SL-PDT) was used for the following experiments. Expression of genes related to vocal fold extracellular matrix formation was analyzed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting. Effects of PDT on cell migration, collagen contraction, and transforming growth factor β-1 (TGF-β1)-induced myofibroblast differentiation were also analyzed.Results: PDT affects the viability of VFFs in a dose-dependent manner. SL-PDT significantly changed the expression profile of VFFs with antifibrotic effects. It also inhibited cell migration, reduced collagen contraction, and reversed the fibroblast-myofibroblast differentiation induced by TGF-β1.Conclusions: SL-PDT induces antifibrotic alterations in VFFs. This could explain the low incidence of vocal fold scar associated with PDT. Moreover, PDT may be useful in treating existing vocal fold scars. Further studies should focus on the in vivo effect of PDT on vocal fold wound healing and scar remodeling.Level Of Evidence: NA Laryngoscope, 128:E323-E331, 2018. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To describe an alternative approach to medialization thyroplasty involving dissection underneath the thyroid cartilage with placement of a Gore-Tex implant, and to evaluate its effect on a range of phonatory measures using an excised canine larynx model.Study Design: Animal model.Methods: On each of eight excised canine larynges, the conditions of normal, paralysis, medialization thyroplasty by standard transthyroid cartilage approach, and medialization thyroplasty by experimental subthyroid cartilage approach were performed. Aerodynamic, acoustic, and mucosal wave parameters were measured for each condition.Results: Compared to the vocal fold paralysis state, both the transthyroid and subthyroid approaches for Gore-Tex insertion resulted in significant decreases in phonation threshold pressure and phonation threshold flow. Both approaches also significantly decreased percent jitter, decreased percent shimmer, and improved signal-to-noise ratio. The mucosal wave was preserved after insertion of the Gore-Tex implant for both approaches. For all the phonatory measures except phonation threshold flow, there were no significant differences between the transthyroid and subthyroid approaches.Conclusions: Gore-Tex implantation via a subthyroid approach in an excised canine larynx model can produce effective medialization, preserve the mucosal wave, and significantly improve aerodynamic and acoustic parameters without meaningful difference compared to a traditional transthyroid approach. The subthyroid approach does not require creation of a thyroid cartilage window and could be a potentially valuable alternative method of performing medialization thyroplasty.Level Of Evidence: NA. Laryngoscope, 128:675-681, 2018. [ABSTRACT FROM AUTHOR]

Objective/hypothesis: The objective of this study was to determine the validity of our laryngopharyngeal reflux (LPR) diagnostic system from our previous study (Witt et al.) against the results of a standard pH probe monitoring. We hypothesized that subjects with abnormal pH probe results demonstrate color and texture abnormalities that would be classified as LPR according to artificial neural network (ANN) analysis.Study Design: Retrospective analysis.Methods: Eighty-two subjects, including 18 pH-positive, 11 pH-negative, and 53 control subjects were tested for LPR through multichannel intraluminal impedance 24-hour pH (MII-24pH) monitoring. Laryngoscopic images of all subjects were obtained. The hue and texture values of seven areas of interest, including true vocal folds, false vocal folds, arytenoids, and interarytenoid, were quantified using a hue calculation and two-dimensional Gabor filtering. These served as inputs for the ANN. This was used to classify images through pattern recognition, and a receiver operating characteristic (ROC) analysis was performed to determine the effectiveness of the diagnosis.Results: Classification accuracy for the combined hue and texture was 87.40%, with an area under the ROC curve of 0.910.Conclusion: Although a previous study conducted classification based on RFS, this study suggests that color and texture analysis may be used to classify images based on the results of pH probing, a more objective approach for diagnosis. Additional studies should include more subjects to produce an even more accurate reading, and will use the color/texture analysis tool to test and confirm this application in a clinical setting.Level Of Evidence: 3B. Laryngoscope, 127:665-670, 2017. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: Type II thyroplasty is an alternative treatment for spasmodic dysphonia, addressing hyperadduction by incising and lateralizing the thyroid cartilage. We quantified the effect of lateralization width on phonatory physiology using excised canine larynges.Methods: Normal closure, hyperadduction, and type II thyroplasty (lateralized up to 5 mm at 1-mm increments with hyperadducted arytenoids) were simulated in excised larynges (N = 7). Aerodynamic, acoustic, and videokymographic data were recorded at three subglottal pressures relative to phonation threshold pressure (PTP). One-way repeated measures analysis of variance assessed effect of condition on aerodynamic parameters. Random intercepts linear mixed effects models assessed effects of condition and subglottal pressure on acoustic and videokymographic parameters.Results: PTP differed across conditions (P < .001). Condition affected percent shimmer (P < .005) but not percent jitter. Both pressure (P < .03) and condition (P < .001) affected fundamental frequency. Pressure affected vibratory amplitude (P < .05) and intrafold phase difference (P < .05). Condition affected phase difference between the vocal folds (P < .001).Conclusions: Hyperadduction increased PTP and worsened perturbation compared to normal, with near normal physiology restored with 1-mm lateralization. Further lateralization deteriorated voice quality and increased PTP. Acoustic and videokymographic results indicate that normal physiologic relationships between subglottal pressure and vibration are preserved at optimal lateralization width, but then degrade with further lateralization. The 1-mm optimal width observed here is due to the small canine larynx size. Future human trials would likely demonstrate a greater optimal width, with patient-specific value potentially determined based on larynx size and symptom severity.Level Of Evidence: NA Laryngoscope, 2016 127:396-404, 2017. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To observe blood perfusion and vascular permeability changes under varying vibration frequency exposures.Study Design: Animal model.Methods: Blood perfusion was measured using laser Doppler flowmetry in eight rabbit auricular vessels (four rabbits) under nonvibration, and 62.5-Hz/1-mm, 125-Hz/1-mm, and 250-Hz/0.5-mm vibration frequency/amplitude exposures. Another 12 rabbits were randomly divided into vibration only and vibration with histamine groups. After 3 hours of continuous 125-Hz, 1-mm amplitude vibration of the auricle, vascular permeability was analyzed by absorbance of Evans blue-albumin complex.Results: Significantly lower blood perfusion was observed in the vibration group, compared with no vibration exposure controls. Blood perfusion decreased 29 ± 16% as the vibration frequency was increased from 62.5 Hz to 125 Hz with the vibration amplitude constant at 1 mm. When the frequency was increased from 125 Hz to 250 Hz, while the amplitude was decreased from 1 mm to 0.5 mm, blood flow perfusion further decreased 29 ± 29%, and the decline tendency in blood perfusion showed no significant difference (P = .992). Meanwhile, in the vibration with histamine group, vascular permeability of the vibrated ears increased significantly compared to the nonvibrated ears (P = .005).Conclusions: Overvibration of the vocal folds due to voice overuse or abuse may significantly reduce blood perfusion, and increase vascular permeability in the vocal fold in inflammatory situations, which may lead to the formation of vocal edema.Level Of Evidence: NA Laryngoscope, 127:148-152, 2017. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To observe the learning curve of the head-mounted microscope in a phonomicrosurgery simulator using cumulative summation (CUSUM) analysis, which incorporates a magnetic phonomicrosurgery instrument tracking system (MPTS).Study Design: Retrospective case series.Methods: Eight subjects (6 medical students and 2 surgeons inexperienced in phonomicrosurgery) operated on phonomicrosurgical simulation cutting tasks while using the head-mounted microscope for 400 minutes total. Two 20-minute sessions occurred each day for 10 total days, with operation quality (Qs ) and completion time (T) being recorded after each session. Cumulative summation analysis of Qs and T was performed by using subjects' performance data from trials completed using a traditional standing microscope as success criteria.Results: The motion parameters from the head-mounted microscope were significantly better than the standing microscope (P < 0.01), but T was longer than that from the standing microscope (P < 0.01). No subject successfully adapted to the head-mounted microscope, as assessed by CUSUM analysis.Conclusion: Cumulative summation analysis can objectively monitor the learning process associated with a phonomicrosurgical simulator system, ultimately providing a tool to assess learning status. Also, motion parameters determined by our MPTS showed that, although the head-mounted microscope provides better motion control, worse Qs and longer T resulted. This decrease in Qs is likely a result of the relatively unstable visual environment that it provides. Overall, the inexperienced surgeons participating in this study failed to adapt to the head-mounted microscope in our simulated phonomicrosurgery environment.Level Of Evidence: 4 Laryngoscope, 126:2295-2300, 2016. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To study the different arm support postures used in phonomicrosurgery by using a magnetic-based phonomicrosurgery instrument tracking system (MPTS). Through quantitative motion parameter data collected from four arm support postures (elbow support [ES], forearm support [FS], forearm and hand support, and no support), phonomicrosurgical operation postures were analyzed and compared.Study Design: Prospective cohort study.Methods: Seven subjects operated on phonomicrosurgical simulation cutting tasks with four arm support postures while being monitored by MPTS. The motion parameters, including operation time, path length, depth perception, and motion smoothness were analyzed. The subjects' cutting quality was also calculated.Results: With the FS, the nondominant hand showed improved S, better D, and shorter P (P < 0.05). Better motion control in the dominant hand resulted from ES posture (P < 0.05). Better operation quality was associated with increased motion control in the nondominant hand.Conclusions: Forearm support resulted in higher steadiness and shorter surgical path in the nondominant hand. In the dominant hand, ES resulted in increased steadiness, shorter surgical path, and better D. The effect of both gravity and wrist dexterity on movement control should be considered when selecting proper arm supports.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis Determine the permeability of excised canine vocal fold lamina propria. Study Design Basic science. Methods Vocal folds were excised from canine larynges and mounted within a device to measure the flow of 0.9% saline through the tissue over time. The resultant fluid volume displaced over time was then used in a variation of Darcy's law to calculate the permeability of the tissue. Permeability was found through each anatomical plane of the vocal fold, with five samples per plane. Permeability was also found for lamina propria stretched to 10%, 20%, and 30% of its initial length to determine the effects of tensile strain on permeability, with five samples per level of strain. Results Permeability was found to be 1.40 × 10−13 m3s/kg through the sagittal plane, 1.00 × 10−13 m3s/kg through the coronal plane, and 4.02 × 10−13 m3s/kg through the axial plane. It was significantly greater through the axial plane than both the sagittal ( P = .025) and coronal ( P = .009) planes. Permeability under strain through the sagittal plane was found to be 1.94 × 10−13 m3s/kg under 10% strain, 3.35 × 10−13 m3s/kg under 20% strain, and 4.80 × 10−13 m3s/kg under 30% strain. The permeability significantly increased after 20% strain ( P < .05). Conclusions Permeability in canine vocal fold lamina propria was found to be increased along the anterior-posterior axis, following the length of the vocal folds. This may influence fluid distribution within the lamina propria during and after vibration. Similarly, permeability increased after 20% strain was imposed on the lamina propria, and may influence vocal fold dynamics during certain phonation tasks. Level of Evidence NA Laryngoscope, 125:941-945, 2015 [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: To investigate the use of the Video-Based Phonomicrosurgery Instrument Tracking System to collect instrument position data during simulated phonomicrosurgery and calculate motion metrics using these data. We used this system to determine if novice subject motion metrics improved over 1 week of training. Study Design: Prospective cohort study. Methods: Ten subjects performed simulated surgical tasks once per day for 5 days. Instrument position data were collected and used to compute motion metrics (path length, depth perception, and motion smoothness). Data were analyzed to determine if motion metrics improved with practice time. Task outcome was also determined each day, and relationships between task outcome and motion metrics were used to evaluate the validity of motion metrics as indicators of surgical performance. Results: Significant decreases over time were observed for path length (P<.001), depth perception (P<.001), and task outcome (P<.001). No significant change was observed for motion smoothness. Significant relationships were observed between task outcome and path length (P<.001), depth perception (P<.001), and motion smoothness (P<.001). Conclusions: Our system can estimate instrument trajectory and provide quantitative descriptions of surgical performance. It may be useful for evaluating phonomicrosurgery performance. Path length and depth perception may be particularly useful indicators. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis To present and evaluate the magnetic-based phonomicrosurgery instrument tracking system, a novel and objective method of acquiring instrument position data during simulated phonomicrosurgery. The position data can be used to compute quantitative motion metrics. This system was used to objectively evaluate the motion performance of novice and expert surgeons during phonomicrosurgical simulations and determine the differences between these groups. Study Design Prospective cohort study. Methods A magnetic-based phonomicrosurgery instrument tracking system was developed, including a workbench, independent task, motion metrics, and computer program. Based on this system, three experts' and six novices' motion data were collected and analyzed. Results Experts demonstrated significantly better motion smoothness along the y-axis for the dominant hand. For the nondominant hand, experts demonstrated better motion smoothness along all three axes, shorter path length, and better depth perception ( P < .05). Experts also demonstrated higher quality of operation ( P < .001). No significant difference in time was noted ( P = .671). Conclusions Parameters derived from magnetic-based motion tracking were able to differentiate between expert and novice surgeons. These parameters have the potential to be used in phonomicrosurgical training as feedback to enhance the training process. Level of Evidence 4 Laryngoscope, 124:2107-2113, 2014 [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to characterize an optimal strategy in managing thoracic esophageal perforation, focusing on the differential diagnosis and treatment of patients with contained versus noncontained perforations and on the importance of the time interval between injury and repair and how that affects the outcome of a primary repair. Methods: A retrospective study was conducted. A strict definition of contained or noncontained perforation was based on a combination of esophagography, chest CT scan, and endoscopy as well as monitoring systemic symptoms. Management options for our cohort included conservative therapy, primary repair and debridement, esophagectomy, and mesh-covered stents. Patients were stratified into two groups according to the time interval after injury: ≤48-h group and >48-h group. Results: Between January 1997 and January 2013, a total of 66 consecutive patients (47 males and 19 females, mean age = 49.1 ± 16.2 years) were treated for thoracic esophageal perforation. Perforation was confirmed by esophagography in 51 patients and by endoscopy in 15 patients. Eighteen patients were assigned to the contained perforation group. All these patients were successfully cured without surgery. The noncontained group included 48 patients; its mortality rate was 7.7 % (3/39) with surgery and 55.6 % (5/9) with stent placement. Compared with the contained group, the noncontained group had a significantly longer length of stay (LOS) (16 ± 3.2 vs. 26.3 ± 18.7 days; p < 0.05) and a higher mortality rate (0 vs. 22.9 %, p < 0.05). In the two time-interval groups, patient characteristics, including age, gender, and comorbidities, etiologic cause, length and location of the perforation, and the incidence of using tissue buttress were similar ( p > 0.05). The incidence of postoperative leak was significantly higher in >48-h group (0 in ≤48-h group vs. 37.5 % in >48-h group; p < 0.01). In addition, the >48-h group had a significantly longer LOS (18.0 ± 9.1 days in ≤48-h group vs. 31.5 ± 18.6 days in >48-h group; p < 0.01). The two deaths occurred in the >48-h group (0 in ≤48-h group vs. 12.5 % in >48-h group; p > 0.05) due to postoperative leaks. Conclusions: Contained or noncontained perforation should be rigorously differentiated. Then, for a contained perforation, conservative therapy coupled with repeated imaging is reasonable treatment. For a noncontained perforation, a primary repair can be safely performed within 48 h after injury. After that, a primary repair is still reasonable but is associated with an increased risk of postoperative leaks. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis To describe the method of inserting a wedge-shaped adjustable balloon implant (wABI) via a minithyrotomy for medialization thyroplasty and evaluate its effect on a range of phonatory parameters using the excised larynx bench apparatus. Study Design Repeated measures with each larynx serving as its own control. Methods A prototype wABI was deployed in six excised canine larynges of various sizes through a minithyrotomy and then filled with saline. Mucosal wave, aerodynamic, and acoustic parameters were measured for three conditions: normal, vocal fold paralysis, and paralysis with the wABI. Results Phonation threshold pressure ( P < .001), flow ( P < .001), and power ( P = .002) were significantly lower for wABI compared to paralysis trials; values did not differ significantly from normal trials. Percent jitter ( P = .002) and percent shimmer ( P = .007) were also significantly decreased compared to the paralysis condition, and values were not significantly different compared to normal. The mucosal wave was preserved after insertion of the wABI. Conclusions Effective vocal fold medialization with preservation of the mucosal wave was observed with the wABI in this preliminary excised larynx experiment. The wABI offers the potential for a minimally invasive insertion in addition to postoperative adjustability. Further studies in living animals and humans are warranted to evaluate clinical utility. Level of Evidence NA. Laryngoscope, 124:942-949, 2014 [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis High-resolution manometry ( HRM) represents a critical advance in the quantification of swallow-related pressure events in the pharynx. Previous analyses of the pressures measured by HRM, though, have been largely two-dimensional, focusing on a single sensor in a given region. We present a three-dimensional approach that combines information from adjacent sensors in a region. Two- and three-dimensional methods were compared for their ability to classify data correctly as normal or disordered. Study Design Case series evaluating new method of data analysis. Methods A total of 1,324 swallows from 16 normal subjects and 61 subjects with dysphagia were included. Two-dimensional single sensor integrals of the area under the curves created by rises in pressure in the velopharynx, tongue base, and upper esophageal sphincter ( UES) were calculated. Three-dimensional multi-sensor integrals of the volume under all curves corresponding to the same regions were also computed. The two sets of measurements were compared for their ability to classify data correctly as normal or disordered using an artificial neural network ( ANN). Results Three-dimensional parameters yielded a maximal classification accuracy of 86.71%±1.47%, while two-dimensional parameters achieved a maximum accuracy of 83.36%±1.42%. Combining two- and three-dimensional parameters with all other variables, including three-dimensional parameters, yielded a classification accuracy of 96.99%±0.51%. Including two-dimensional parameters yielded a classification accuracy of 96.32%±1.05%. Conclusion Three-dimensional analysis led to improved classification of swallows based on pharyngeal HRM. Artificial neural network performance with both two-dimensional and three-dimensional analyses was effective, classifying a large percentage of swallows correctly, thus demonstrating its potential clinical utility. Level of Evidence 4. Laryngoscope, 2013 [ABSTRACT FROM AUTHOR]

Silk fibroin (SF) shows promise for tissue engineering and other biomedical applications due to its excellent biocompatibility, unique biomechanical properties, and controllable biodegradability. The particulate form of SF materials may have many potential uses, including the use as a filler for tissue defects or as a controlled-release agent for drug delivery. However, many past in vivo and in vitro studies evaluating the biocompatibility and biodegradability of SF have involved bulk implants. It is essential to evaluate the inflammatory effects of SF particles before further use. In this study, two different sizes of SF particles were evaluated to assess their impact on the release of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, in comparison with lipopolysaccharide positive control stimulation. The inflammatory processes were characterized using real-time reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and light microscopy evaluations. The results indicated that small silk fibroin particles and large silk fibroin particles, in culture with RAW 264.7 murine macrophage cells for 24 h, caused up-regulation of mRNA coding for TNF-α, which indicated that both size of particles have potential inflammatory effects. There was a statistically significant increase in this up-regulation under small silk fibroin stimulation. However, the immunosorbent assay suggested that there was virtually no observed release of IL-1β, IL-6, or TNF-α, relative to the control group. The results suggest that SF particles of the chosen dimensions may have good biocompatibility in culture with RAW 264.7 murine macrophages. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Besides the classical sexual receptors, the expression of a recently clarified transmembrane G protein-coupled receptor (GPR30) has not been reported in the vocal fold so far. We aimed to study whether GPR30 is expressed in the human vocal fold. Study Design: Experimental study using pathologic human vocal fold tissues. Methods: Reverse-transcription polymerase chain reaction and immunohistochemistry were used to detect the GPR30 expression in a total of 83 vocal fold samples. Results: A total of 66% of the specimens tested were GPR30 mRNA positive, and 54% of the sections were revealed to be GPR30 immunostaining positive in the plasma membrane as well as the nucleus in the epithelial cells. Conclusions: The GPR30 expression both in mRNA and protein level could be detected in the human vocal fold. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: To use classification algorithms to classify swallows as safe, penetration, or aspiration based on measurements obtained from pharyngeal high-resolution manometry (HRM) with impedance. Study Design: Case series evaluating new method of data analysis. Methods: Multilayer perceptron, an artificial neural network (ANN), was evaluated for its ability to classify swallows as safe, penetration, or aspiration. Data were collected from 25 disordered subjects swallowing 5- or 10-mL boluses. Following extraction of relevant parameters, a subset of the data was used to train the models, and the remaining swallows were then independently classified by the ANN. Results: A classification accuracy of 89.4 ± 2.4% was achieved when including all parameters. Including only manometry-related parameters yielded a classification accuracy of 85.0 ± 6.0%, whereas including only impedance-related parameters yielded a classification accuracy of 76.0 ± 4.9%. Receiver operating characteristic analysis yielded areas under the curve of 0.8912 for safe, 0.8187 for aspiration, and 0.8014 for penetration. Conclusions: Classification models show high accuracy in classifying swallows from dysphagic patients as safe or unsafe. HRM-impedance with ANN represents one method that could be used clinically to screen for patients at risk for penetration or aspiration. Laryngoscope, 2013 [ABSTRACT FROM AUTHOR]

The article presents a research study aimed at analyzing the effect of vocal fold injury on lateral phase difference and vibratory amplitude among dogs. The study is undertaken through repeated measurement of excised canine larynx serving. The results of the study show that medial and anterior injuries lessen the vibratory amplitude among dogs.

Objective: Laryngeal function can be evaluated from multiple perspectives, including aerodynamic input, acoustic output, and mucosal wave vibratory characteristics. To determine the classifying power of each of these, we used a multilayer perceptron artificial neural network (ANN) to classify data as normal, glottic insufficiency, or tension asymmetry. Study design: Case series analyzing data obtained from excised larynges simulating different conditions. Methods: Aerodynamic, acoustic, and videokymographic data were collected from excised canine larynges simulating normal, glottic insufficiency, and tension asymmetry. Classification of samples was performed using a multilayer perceptron ANN. Results: A classification accuracy of 84% was achieved when including all parameters. Classification accuracy dropped below 75% when using only aerodynamic or acoustic parameters and below 65% when using only videokymographic parameters. Conclusions: Samples were classified with the greatest accuracy when using a wide range of parameters. Decreased classification accuracies for individual groups of parameters demonstrate the importance of a comprehensive voice assessment when evaluating dysphonia. Laryngoscope, 2012 [ABSTRACT FROM AUTHOR]

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300mm to 700mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Laryngoscope, 2012 [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: Digital kymography (DKG) can provide objective quantitative data about vocal fold vibration, which may help distinguish normal from pathological vocal folds as well as nodules from polyps. Study Design: Case-control study. Methods: There were 87 subjects who were separated into three groups: control, nodules, and unilateral polyps, and examined using a high-speed camera attached to an endoscope. Videos were analyzed using a custom MATLAB program, and three DKG line-scan positions (25%, 50%, and 75% of vocal fold length) were used in statistical analyses to compare vocal fold vibrational frequency, amplitude symmetry index (ASI), amplitude order, and vertical and lateral phase difference (VPD and LPD, respectively). Results: Significant differences among groups were found in all vibrational parameters except frequency. Polyps and nodules groups exhibited greater ASI values (less amplitude symmetry) than the control group. Although the control group consistently showed its largest amplitudes at the midline, the polyps group showed larger amplitudes toward the posterior end of the vocal folds. A significant anterior-posterior pattern in amplitude was not found in the nodules group. LPD values were usually largest (most symmetrical) in the control group, followed by nodules and polyps. LPD at the 25% position allowed for differentiation between polyp and nodule groups. The largest VPD (more pronounced mucosal wave) values were usually found in the control group. Conclusions: Vibratory characteristics of normal and pathological vocal folds were quantitatively examined and compared using multiline DKG. These findings may allow for better characterization of pathologies and eventually assist in improving the clinical utility of DKG. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: The purpose of this study was to compare the clinical effectiveness of type I thyroplasty, injection laryngoplasty, and graft implantation for the treatment of vocal fold scar and pathologic sulcus vocalis. Study Design: Prospective, multi-arm, quasi-experimental research design.Methods: Twenty-eight patients with newly diagnosed vocal fold scar and/or pathologic sulcus vocalis were assigned to one of three treatment modalities: type I thyroplasty (n ¼ 9), injection laryngoplasty (n ¼ 9), and graft implantation (n ¼ 10). Psychosocial, auditory perceptual, acoustic, aerodynamic, and videostroboscopic data were collected pretreatment and at1, 6, 12, and 18 months posttreatment. Results: Type I thyroplasty and graft implantation both resulted in reduced voice handicap with no concomitant improvement in auditory-perceptual, acoustic, aerodynamic, or vocal fold physiologic performance. Injection laryngoplasty resulted in no improvement on any vocal function index. Patients who underwent graft implantation exhibitedthe slowest improvement trajectory across the 18-month follow-up period. Conclusions: A persistent challenge in this area is that no single treatment modality is successful for the majority of patients, and there is no evidence-based decision algorithm for matching a given treatment to a given patient.Progress therefore requires the identification and categorization of predictive clinical features that can drive evidence-based treatment assignment. [ABSTRACT FROM AUTHOR]

Objective: We present the adjustable balloon implant (ABI), a novel implant to be used in type I thyroplasty for the treatment of vocal fold paralysis. The ABI offers the same medialization provided by other implants, but can easily be catered to individual patient anatomy as well as modified postoperatively without the need for a revision thyroplasty. Study Design: Repeated measures with each larynx serving as its own control. Methods: Medialization thyroplasty (MT) with the ABI was performed on five excised canine larynges. Mucosal wave, aerodynamic, and acoustic parameters were measured for three conditions: normal; right vocal fold paralysis; and paralysis with the ABI. Results: Insertion of the ABI resulted in significant decreases in both phonation threshold pressure and phonation threshold flow. Perturbation parameters of percent jitter and percent shimmer were also significantly decreased and restored to normal levels. Signal-to-noise ratio was significantly increased to the normal level as well. The mucosal wave was preserved after implant insertion. Conclusions: This preliminary experiment showing significant improvements in aerodynamic and acoustic parameters demonstrates the potential of the ABI as a thyroplasty implant. Effective medialization and preservation of the mucosal wave combined with postoperative adjustability makes it a potentially valuable clinical device. [ABSTRACT FROM AUTHOR]

Objectives/Hypothesis: To investigate the potential usefulness of indirect computed tomography lymphography (CT-LG) with iopamidol in the detection of cervical lymph node metastases in a VX2 rabbit tongue cancer model. Study Design: Randomized controlled trial. Methods: Thirty-seven rabbits were randomly divided into control (n = 7) and tongue tumor-bearing (n = 30) groups. In the control group, indirect CT-LG was performed with 0.5- and 0.25-mL injections of iopamidol in the right and left tongue submucosa, respectively. In the tumor-bearing group, indirect CT-LG with 0.5 mL of iopamidol was performed on day 11 (n = 8), 14 (n = 8), 21 (n = 8), or 28 (n = 6) after carcinoma transplant. The correlation between indirect CT-LG and histopathology was investigated. Results: In normal rabbits, oval or round enhanced cervical lymph nodes in each side of the neck were visualized by indirect CT-LG. In tumor-bearing rabbits, one enhanced lymph node on each side of the neck was visualized with or without filling defects in all rabbits except two on day 28 in which lymph nodes were not enhanced. The sensitivity, specificity, accuracy, and positive and negative predictive values for using filling defects on CT-LG as a diagnostic criterion were 77.4%, 77.8%, 77.6%, 80%, and 75%, respectively. Indirect CT-LG detected 84.6% of 2- to 6-mm intranodal tumor deposits. Conclusions: Indirect CT-LG may be useful for differentiating metastatic from nonmetastatic lymph nodes. [ABSTRACT FROM AUTHOR]

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 (VE), percent jitter, and percent shimmer. After the optimal degree of rotation was determined, the arytenoid was hypo- and hyperrotated 10% 6 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°. VE differed significantly across experimental conditions (P = .003). Optimal AA produced the highest VE 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: VE 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. [ABSTRACT FROM AUTHOR]

Objective. Evaluate the effect of vocal fold surface dehydration on mucosal wave amplitude and frequency.Study Design. Controlled test-retest.Setting. Larynges were mounted on an excised larynx phonation system and attached to a pseudolung in a triple-walled sound-attenuated room that eliminated background noise and maintained a stabilized room temperature and humidity level.Subjects and Methods. High-speed video was recorded for 8 excised canine larynges during exposure to dehumidified air at 20 cm H2O. Control trials consisted of high-speed videos recorded for 2 excised canine larynges during exposure to humidified air at the same pressure.Results. In the majority of larynges, increased levels of dehydration were correlated with decreased amplitude and frequency. The slope of the linear regression fitted to the change in amplitude (P = .003) and the percent change (P < .001) between the initial and final trials were significantly decreased in dehydrated larynges. These measurements with respect to the change in frequency were also significantly decreased in dehydrated larynges (P < .001; P = .027).Conclusion. Vocal fold surface dehydration caused a decrease in mucosal wave amplitude and frequency. This study provides objective, quantitative support for the mechanism of voice deterioration observed after extreme surface dehydration. [ABSTRACT FROM PUBLISHER]

Objective: To determine the effect of bolus volume on pharyngeal swallowing using high-resolution manometry (HRM). Study Design: Repeated measures with subjects serving as own controls. Methods: Twelve subjects swallowed four bolus volumes in the neutral head position: saliva; 5 mL water; 10 mL water; and 20 mL water. Pressure measurements were taken along the length of the pharynx using a high-resolution manometer, with emphasis placed on the velopharynx, tongue base, and upper esophageal sphincter (UES). Variables were analyzed across bolus volumes using three-way repeated measures analysis of covariance (ANCOVA) investigating the effect of sex, bolus volume, and pharynx length. Pearson's product moment tests were performed to evaluate how pharyngeal pressure and timing events changed across bolus volume. Results: Velopharyngeal duration, maximum tongue base pressure, tongue base pressure rise rate, UES opening duration, and total swallow duration varied significantly across bolus volume. Sex did not have an effect, whereas pharynx length appeared to affect tongue base pressure duration. Maximum velopharyngeal pressure and minimum UES pressure had a direct relationship with bolus volume, whereas maximum tongue base pressure had an inverse relationship. Velopharyngeal pressure duration, UES opening duration, and total swallow duration increased as bolus volume increased. Conclusions: Differences in pharyngeal pressures and timing of key pressure events were detected across varying bolus volumes. Knowing the relationships between bolus volume and pharyngeal pressure activity can be valuable when diagnosing and treating dysphagic patients. [ABSTRACT FROM AUTHOR]

Objectives: Vocal fold injury can be irreversible, leading to vocal fold scarring, with permanent functional effects and no optimal treatment. A porcine model of vocal fold scarring was used to test effects of decorin and primed vocal fold fibroblasts in vitro using a cell migration assay and immunoblotting, and by using functional measurements of porcine larynges and excised porcine vocal folds. Methods: In vitro: primary pig vocal fold fibroblasts (PVFFs) were subjected to cell migration assays (scratch) and treated with decorin 20 μg/mL, hepatocyte growth factor (HGF) 200 ng/mL, epidermal growth factor (EGF) 1 nM, or transforming growth factor-β1 10 ng/mL. Cells also underwent decorin dose response testing. Scratch assays were analyzed in MetaMorph® Imaging; cell lysates were processed for MMP-8 and type I collagen content. Eleven pigs underwent unilateral vocal fold stripping procedures. At day 3 postoperatively, subjects underwent superficial injection into the affected vocal fold either with decorin 20 μg/mL or 1 × 106 HGF-primed fibroblasts. Larynges were harvested and either used for ex vivo laryngeal testing or for rheological testing. Results: Scratch assay indicated significantly reduced cell migration in PVFFs treated with decorin or HGF. MMP-8 production was increased (P <0.01) and collagen was decreased in cells treated with decorin at increasing doses. Viscoelastic measurements suggested somewhat increased stiffness for decorin treated samples. Ex vivo aerodynamic testing suggested improved vocal efficiency scores in decorintreated larynges. Conclusions: Decorin has a noticeable effect on PVFF migration in vitro and appears to increase vocal fold stiffness but either does not change or slightly increases vocal efficiency. [ABSTRACT FROM AUTHOR]

Objectives: To describe the implementation of a program for surgical education in laryngology. Methods: Items necessary to modify a temporal bone lab for laryngeal dissection purposes were identified, and costs to do so were calculated. The prices and availability of human and canine laryngeal specimens to be used for teaching purposes were then compared. Endoscopic and open laryngeal surgery were performed on canine larynges to determine suitability as a teaching model. A laryngeal dissection course with teaching objectives was created and instituted in an Otolaryngology-Head and Neck Surgery residency training program. Results: Modifications to convert an existing temporal bone lab into a laryngeal dissection lab cost $7,425. Canine larynges were found to strongly resemble human larynges and were easily used in a teaching model. They were more easily acquired and less expensive than human larynges. A novel dissection approach was created to maximize utility of a single cadaveric laryngeal specimen. Development of a laryngeal dissection manual facilitated a laryngeal dissection course. Conclusions: A laryngeal dissection educational course can be instituted with simple and relatively inexpensive modifications to an existing temporal bone laboratory. Canine larynges can be substituted for human larynges for a substantial cost savings without educational compromise. The educational methods demonstrated can be easily duplicated at other training sites. [ABSTRACT FROM AUTHOR]