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Easwaran M, Maria CS, Martinez JD, Hung B, Yu X, Soo J, Kimura A, Gross ER, Erickson-DiRenzo E. Effects of Short-term Electronic(e)-Cigarette Aerosol Exposure in the Mouse Larynx. Laryngoscope 2024; 134:1316-1326. [PMID: 37698394 PMCID: PMC10922082 DOI: 10.1002/lary.31043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/17/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023]
Abstract
OBJECTIVES The effects of electronic cigarettes (e-cigarettes) on the larynx are relatively unknown. This study examined the short-term effects of e-cigarette inhalation on cellular and inflammatory responses within the mouse laryngeal glottic and subglottic regions after exposure to pod-based devices (JUUL). METHODS Male C57BL6/J mice (8-9 weeks) were assigned to control (n = 9), JUUL flavors Mint (JMi; n = 10) or Mango (JMa; n = 10). JUUL mice were exposed to 2 h/day for 1, 5, and 10 days using the inExpose inhalation system. Control mice were in room air. Vocal fold (VF) epithelial thickness, cell proliferation, subglandular area and composition, inflammatory cell infiltration, and surface topography were evaluated in the harvested larynges. Mouse body weight and urinary nicotine biomarkers were also measured. Chemical analysis of JUUL aerosols was conducted using selective ion flow tube mass spectrometry. RESULTS JUUL-exposed mice had reduced body weight after day 5. Urinary nicotine biomarker levels indicated successful JUUL exposure and metabolism. Quantitative analysis of JUUL aerosol indicated that chemical constituents differ between JMi and JMa flavors. VF epithelial thickness, cellular proliferation, glandular area, and surface topography remained unchanged after JUUL exposures. Acidic mucus content increased after 1 day of JMi exposure. VF macrophage and T-cell levels slightly increased after 10 days of JMi exposures. CONCLUSIONS Short-term e-cigarette exposures cause minimal flavor- and region-specific cellular and inflammatory changes in the mouse larynx. This work provides a foundation for long-term studies to determine if these responses are altered with multiple e-cigarette components and concentrations. LEVEL OF EVIDENCE N/A Laryngoscope, 134:1316-1326, 2024.
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Affiliation(s)
- Meena Easwaran
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Chloe Santa Maria
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Joshua D. Martinez
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Barbara Hung
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Xuan Yu
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Joanne Soo
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Akari Kimura
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Eric R. Gross
- Department of Anesthesiology, Perioperative and Pain Medicine, School of Medicine, Stanford University, Stanford, CA
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
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Khan MI, Easwaran M, Martinez JD, Kimura A, Erickson-DiRenzo E. Method for Collecting Single Epithelial Cells from the Mouse Larynx. Laryngoscope 2024; 134:786-794. [PMID: 37602769 PMCID: PMC10841475 DOI: 10.1002/lary.30970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/22/2023]
Abstract
OBJECTIVE The larynx is lined by specialized epithelial cell populations. Studying molecular changes occurring in individual epithelial cell types requires a reliable method for removing these cells from the larynx. Our objective was to develop a method to harvest individual epithelial cells from the mouse larynx while minimizing contamination from non-laryngeal sites and non-epithelial laryngeal cells. METHODS Mice were euthanized, and the larynx was carefully exposed and separated from non-laryngeal sites. A small dental brush was inserted into the laryngeal inlet and rotated to obtain epithelial cells. Cells were transferred to collection media, counted, and cytospin preparations stained for laryngeal epithelial (i.e., Pan-Keratin, EpCAM, NGFR, p63, K5, β-tubulin, MUC5AC) and non-epithelial (i.e., vimentin) cell markers. Histopathology was completed on brushed laryngeal tissue sections to evaluate the depth of cell collection. Preliminary Single-cell RNA sequencing (scRNA-seq) was performed to confirm this method can capture diverse laryngeal cell types. RESULTS We collected 6000-8000 cells from a single larynx and 35000-40000 cells from combining brushings from three tissues. Histopathology demonstrated brushing removed the epithelial layer of the larynx and some underlying tissue. Immunofluorescence staining demonstrated the phenotype of harvested cells was primarily epithelial. Preliminary scRNA-seq was successfully conducted and displayed nine unique cell clusters. CONCLUSION We developed a reliable method of harvesting individual epithelial cells from the mouse larynx. This method will be useful for collection of laryngeal cells for a variety of downstream cellular and molecular assays, including scRNA-seq, protein analyses, and cell-culture-based experiments, following laryngeal injury. LEVEL OF EVIDENCE NA Laryngoscope, 134:786-794, 2024.
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Affiliation(s)
- Mohammed Imran Khan
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Meena Easwaran
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
- Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA
| | - Joshua D. Martinez
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Akari Kimura
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head & Neck Surgery, School of Medicine, Stanford University, Stanford, CA
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Nuyen B, Qian ZJ, Rakkar M, Thomas JP, Erickson-DiRenzo E, Sung CK. Diagnosis and Management of Vocal Complications after Chondrolaryngoplasty. Laryngoscope 2023; 133:2301-2307. [PMID: 36576093 DOI: 10.1002/lary.30518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 10/09/2022] [Accepted: 10/10/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Transfeminine patients (transwomen/feminine nonbinary folks assigned male at birth) can undergo chondrolaryngoplasty ("tracheal shave") to feminize their neck appearance. While isolated cases of vocal complications have been reported following the procedure, aggregated outcomes have not been quantitatively studied. We present acoustic and stroboscopic data to describe a patient cohort with vocal complications after chondrolaryngoplasty and discuss reparative surgical technique. METHODS Subjective and objective data, including videostroboscopy, were collected from patients with voice complaints after chondrolaryngoplasty. Dislocated anterior commissures were reconstructed with feminization laryngoplasty. Postoperative voice data were recorded and statistically compared to preoperative data using paired t-tests. RESULTS On consecutive chart review, of the 94 transfeminine women with prior outside history of chondrolaryngoplasty, 27 (29%) reported chronic postoperative hoarseness, deepened pitch, or loss of upper register. On endoscopy, short, lax vocal folds with persistent anterior glottic gap and phase asymmetry were commonly noted; anterior commissure dislocation was confirmed in-office by using needle localization through absent thyroid cartilage. After open resuspension of the anterior commissure with feminization laryngoplasty, post-repair modal-speaking, minimum, and maximum fundamental frequencies (F0) increased on average by 7, 8, and 5 semitones, respectively (p < 0.01), when compared to pre-repair values. On average, perioperative maximum phonation time did not change significantly (p = 0.15). Average self-assessment of vocal femininity increased by 48% (p < 0.01). CONCLUSION Anterior commissure dislocation should be suspected with signs of vocal impairment after chondrolaryngoplasty. Following proper diagnosis, resuspension of the anterior commissure via feminization laryngoplasty approach can be an effective reparative technique. LEVEL OF EVIDENCE This work represents a 2011 OCEBM Level 4 evidence as a case series Laryngoscope, 133:2301-2307, 2023.
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Affiliation(s)
- Brian Nuyen
- Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
- The Voice Doctor Clinic, Portland, Oregon, U.S.A
| | - Z Jason Qian
- Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Meher Rakkar
- College of Medicine-Phoenix, The University of Arizona, Phoenix, Arizona, U.S.A
| | | | - Elizabeth Erickson-DiRenzo
- Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - C Kwang Sung
- Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
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Martinez JD, Easwaran M, Ramirez D, Erickson-DiRenzo E. Effects of Electronic (E)-cigarette Vapor and Cigarette Smoke in Cultured Vocal Fold Fibroblasts. Laryngoscope 2023; 133:139-146. [PMID: 35213064 DOI: 10.1002/lary.30073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/14/2022] [Accepted: 02/14/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The public use of electronic-cigarettes (e-cigs) is rapidly growing. When heated, e-cigs produce a vapor that is inhaled. The vocal folds are among the first tissues exposed to this insult. However, the impact of e-cigs on vocal fold health is almost entirely unknown. Our objective was to evaluate the effects of e-cig vapor on cultured human vocal fold fibroblasts (hVFFs), the primary cell type of the lamina propria. We compared the cellular effects of e-cig vapor without and with nicotine and conventional cigarette smoke. STUDY DESIGN In vitro. METHODS E-cig vapor extract (EVE) and cigarette smoke extract (CSE) were created by bubbling vapor and smoke, respectively, into the cell culture medium. hVFFs were exposed to EVE without or with nicotine or CSE for 24 hours. Untreated cells were used as a control group. Cells were harvested, and cytotoxicity, extracellular matrix and inflammatory gene expression, and DNA damage were assessed. RESULTS Undiluted EVE without and with nicotine reduced the viability of hVFFs to a cytotoxic level. CSE reduced hVFFs viability to a greater extent than EVE and induced DNA damage as measured by DNA double-strand breaks. No changes in gene expression were observed following EVE or CSE exposure. CONCLUSION EVE induces cytotoxicity in hVFFs. However, cellular responses were greater following exposure to CSE, suggesting cigarette smoke may induce more harm, at least in the short term. Findings from this investigation improve our understanding of responses of hVFFs to e-cigs and form the basis for an in vitro methodology to study the vocal fold responses to these products. LEVEL OF EVIDENCE NA Laryngoscope, 133:139-146, 2023.
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Affiliation(s)
- Joshua D Martinez
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Meena Easwaran
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Daniel Ramirez
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
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Easwaran M, Martinez JD, Kim JB, Erickson-DiRenzo E. Modulation of mouse laryngeal inflammatory and immune cell responses by low and high doses of mainstream cigarette smoke. Sci Rep 2022; 12:18667. [PMID: 36333510 PMCID: PMC9636197 DOI: 10.1038/s41598-022-23359-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Cigarette smoking is a major risk factor for laryngeal diseases. Despite well-documented cigarette smoke (CS) induced laryngeal histopathological changes, the underlying immunopathological mechanisms remain largely unexplored. The goal of this study was to evaluate inflammatory and immune cell responses in a CS-exposed larynx. Specifically, we used a 4-week subacute whole-body CS inhalation mouse model to assess these responses in the laryngeal mucosa upon exposure to low (LD; 1 h/day) and high dose (HD; 4 h/day) CS. Laryngeal tissues were harvested and evaluated using a 254-plex NanoString inflammation panel and neutrophil/macrophage/T-cell immunohistochemistry (IHC). NanoString global and differential gene expression analysis revealed a unique expression profile only in the HD group, with 26 significant differentially expressed genes (DEGs). StringDB KEGG pathway enrichment analysis revealed the involvement of these DEGs with pro-inflammatory pathways including TNF/TNFα and IL-17. Furthermore, inflammatory responses remained inhibited in conjunction with predicted activated states of anti-inflammatory regulators like PPARγ and NFE2L2 upon Ingenuity Pathway Analysis (IPA). Subglottic T-cell levels remained significantly inhibited as corroborated by IPA predictions. Overall, our key findings are consistent with HD exposures being anti-inflammatory and immunosuppressive. Furthermore, the identification of important regulatory genes and enriched pathways may help improve clinical interventions for CS-induced laryngeal diseases.
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Affiliation(s)
- Meena Easwaran
- grid.168010.e0000000419368956Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA USA ,grid.168010.e0000000419368956Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA USA
| | - Joshua D. Martinez
- grid.168010.e0000000419368956Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA USA
| | - Juyong Brian Kim
- grid.168010.e0000000419368956Department of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, CA USA
| | - Elizabeth Erickson-DiRenzo
- grid.168010.e0000000419368956Division of Laryngology, Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA USA
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Pfeifer KJ, Cook AJ, Yankulova JK, Mortimer BJP, Erickson-DiRenzo E, Dhall R, Montaser-Kouhsari L, Tass PA. Clinical Efficacy and Dosing of Vibrotactile Coordinated Reset Stimulation in Motor and Non-motor Symptoms of Parkinson's Disease: A Study Protocol. Front Neurol 2021; 12:758481. [PMID: 34867742 PMCID: PMC8636796 DOI: 10.3389/fneur.2021.758481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 10/12/2021] [Indexed: 11/13/2022] Open
Abstract
Enhanced neuronal synchronization of the subthalamic nucleus (STN) is commonly found in PD patients and corresponds to decreased motor ability. Coordinated reset (CR) was developed to decouple synchronized states causing long lasting desynchronization of neural networks. Vibrotactile CR stimulation (vCR) was developed as non-invasive therapeutic that delivers gentle vibrations to the fingertips. A previous study has shown that vCR can desynchronize abnormal brain rhythms within the sensorimotor cortex of PD patients, corresponding to sustained motor relief after 3 months of daily treatment. To further develop vCR, we created a protocol that has two phases. Study 1, a double blinded randomized sham-controlled study, is designed to address motor and non-motor symptoms, sensorimotor integration, and potential calibration methods. Study 2 examines dosing effects of vCR using a remote study design. In Study 1, we will perform a 7-month double-blind sham-controlled study including 30 PD patients randomly placed into an active vCR or inactive (sham) vCR condition. Patients will receive stimulation for 4 h a day in 2-h blocks for 6 months followed by a 1-month pause in stimulation to assess long lasting effects. Our primary outcome measure is the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III off medication after 6 months of treatment. Secondary measures include a freezing of gait (FOG) questionnaire, objective motor evaluations, sensorimotor electroencephalography (EEG) results, a vibratory temporal discrimination task (VTDT), non-motor symptom evaluations/tests such as sleep, smell, speech, quality of life measurements and Levodopa Equivalent Daily Dose (LEDD). Patients will be evaluated at baseline, 3, 6, and 7 months. In the second, unblinded study phase (Study 2), all patients will be given the option to receive active vCR stimulation at a reduced dose for an additional 6 months remotely. The remote MDS-UPDRS part III off medication will be our primary outcome measure. Secondary measures include sleep, quality of life, objective motor evaluations, FOG and LEDD. Patients will be evaluated in the same time periods as the first study. Results from this study will provide clinical efficacy of vCR and help validate our investigational vibrotactile device for the purpose of obtaining FDA clearance. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT04877015.
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Affiliation(s)
- Kristina J. Pfeifer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
| | - Alex J. Cook
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
| | - Jessica K. Yankulova
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
| | | | - Elizabeth Erickson-DiRenzo
- Department of Otolarygology Head and Neck Surgery/Laryngology Division, Stanford University School of Medicine, Stanford, CA, United States
| | - Rohit Dhall
- Department of Neurology, Center for Neurodegenerative Disorders, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Leila Montaser-Kouhsari
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Peter A. Tass
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, United States
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Erickson-DiRenzo E, Easwaran M, Martinez JD, Dewan K, Sung CK. Mainstream Cigarette Smoke Impacts the Mouse Vocal Fold Epithelium and Mucus Barrier. Laryngoscope 2021; 131:2530-2539. [PMID: 33864646 PMCID: PMC8502200 DOI: 10.1002/lary.29572] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/26/2021] [Accepted: 04/09/2021] [Indexed: 12/24/2022]
Abstract
OBJECTIVES/HYPOTHESIS Cigarette smoke (CS) is a primary risk factor for the development of numerous benign and malignant laryngeal diseases. The epithelium and mucus lining the vocal folds (VF) are the first barriers against CS. The primary objective of this study was to investigate epithelial and mucus barrier changes in the mouse laryngeal mucosa upon exposure to subacute CS. The secondary objective was to compare mucus barrier changes in mice and human smokers and nonsmokers. Study Design Animal model. METHODS Mice were exposed to CS for 4 weeks for 4 hours (N = 12, high dose [HD]) or 1 hour (N = 12, low dose [LD]) per day. Air-exposed mice were used as a control group (N = 10). Larynges were harvested and VF epithelial barrier integrity was evaluated including cellular proliferation and expression of cell junctions. We also investigated mucus production by examining mucus cell area and mucin expression in mice and human smokers and nonsmokers. RESULTS HD CS increased VF epithelial cellular proliferation but did not alter the expression of cell junctions. HD CS also induced hypertrophy of the mucus-producing submucosal glands. However, only LD CS increased MUC5AC gene expression. MUC5AC staining appeared elevated in laryngeal specimens from smokers, but this was not significant as compared to nonsmokers. CONCLUSIONS These findings help us identify potential adaptive mechanisms to CS exposure as well as set the foundation for further study of key aspects of epithelial and mucus barrier integrity that may be implicated in laryngeal disease development following prolonged smoking. LEVEL OF EVIDENCE NA Laryngoscope, 131:2530-2539, 2021.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Meena Easwaran
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Joshua D Martinez
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Karuna Dewan
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
| | - Chih Kwang Sung
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, U.S.A
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Nuyen BA, Qian ZJ, Campbell RD, Erickson-DiRenzo E, Thomas J, Sung CK. Feminization Laryngoplasty: 17-Year Review on Long-Term Outcomes, Safety, and Technique. Otolaryngol Head Neck Surg 2021; 167:112-117. [PMID: 34399638 DOI: 10.1177/01945998211036870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Transfeminine patients can experience significant gender dysphoria in vocal communication. Feminization laryngoplasty (FL) is a gender-affirming surgery developed to elevate speaking vocal range, as well as alter vocal resonance and laryngeal cosmesis. The purpose here was to appraise FL's long-term voice outcomes across a 17-year review period. STUDY DESIGN Level III, retrospective study and description of technique. SETTING A single-institution transfeminine voice clinic. METHODS Voice data (speaking fundamental frequency [F0], lowest F0, highest F0, F0 range in both Hertz and semitones, and maximum phonation time [MPT]) were collected and assessed. Self-assessment of voice femininity and complications were documented. RESULTS The 162 patients, all transfeminine women, had a mean age of 40 years with 36-month mean follow-up. There were significant increases in mean speaking F0 (Δ = 50 ± 30 Hz, Δ = 6 ± 3 semitones; P < .001) and mean change in lowest F0 (Δ = 58 ± 31 Hz, Δ = 8 ± 4 semitones; P < .001). There was no significant difference in mean change in highest F0 or MPT. There was significant improvement (Δ = 60% ± 39%; P < .001) in perceptual self-assessment of vocal femininity. There was a 1.2% rate of major postoperative complications requiring inpatient admission or operative intervention. There were no differences in vocal outcomes between those patients who had less than 1-year follow-up and those who had 5-year follow-up. CONCLUSION FL in this cohort was a safe and effective technique for increasing mean speaking F0, mean lowest F0, and voice gender perception over a prolonged follow-up period. These findings add to the possible treatments aimed at addressing the morbid dysphoria related to voice and communication for our transfeminine patients.
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Affiliation(s)
- Brian A Nuyen
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Z Jason Qian
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Ross D Campbell
- Department of Otolaryngology-Head and Neck Surgery, University of Ottawa, Ontario, Canada
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA.,Division of Laryngology, Stanford University School of Medicine, Stanford, California, USA
| | - James Thomas
- James P. Thomas, MD Voicedoctor Clinic, Portland, Oregon, USA
| | - C Kwang Sung
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, California, USA.,Division of Laryngology, Stanford University School of Medicine, Stanford, California, USA
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Kearney A, Searl J, Erickson-DiRenzo E, Doyle PC. The Impact of COVID-19 on Speech-Language Pathologists Engaged in Clinical Practices With Elevated Coronavirus Transmission Risk. Am J Speech Lang Pathol 2021; 30:1673-1685. [PMID: 34161739 DOI: 10.1044/2021_ajslp-20-00325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Purpose This study assessed and described potential clinical practice changes secondary to COVID-19 that emerged as an early response to the pandemic for speech-language pathologists (SLPs) engaged in voice, alaryngeal, and swallowing activities that may increase the risk of virus transmission. Method SLPs from the United States and Canada (n = 665) who were engaged in clinical activities that might elevate the risk of COVID-19 exposure completed an online survey regarding their clinical practices. Topics assessed included potential clinical service modifications, COVID-19 testing and health, and potential financial impacts in the early time period of the pandemic. Results The percentage of SLPs completing the most endoscopic procedures prepandemic (≥ 10/week) was reduced from 39% of respondents to 3% due to the pandemic. Those who completed the most tracheoesophageal puncture voice prosthesis changes (≥ 5/week) reported a reduction in frequency from 24% to 6%. Twenty-five percent of SLPs reported that they were tested for COVID-19, and 6% reported a positive result. Descriptive statistics suggest that COVID-19 testing rates of SLPs, the percentage of SLPs experiencing a financial impact, and the percentage who were furloughed varied across SLP work setting. Conclusions These findings provide the first data characterizing the impact on COVID-19 on clinical practice for SLPs engaged in procedures such as endoscopy and laryngectomy care. The results indicate that, as frontline workers, SLPs were directly impacted in their practice patterns, personal health, safety, and financial security, and that these reported impacts occurred differently across SLP work settings.
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Affiliation(s)
- Ann Kearney
- Department of Otolaryngology - Head and Neck Surgery, Division of Laryngology, Stanford University School of Medicine, CA
| | - Jeff Searl
- Department of Communicative Sciences and Disorders, Michigan State University, East Lansing
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head and Neck Surgery, Division of Laryngology, Stanford University School of Medicine, CA
| | - Philip C Doyle
- Department of Otolaryngology - Head and Neck Surgery, Division of Laryngology, Stanford University School of Medicine, CA
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Erickson-DiRenzo E, Singh SP, Martinez JD, Sanchez SE, Easwaran M, Valdez TA. Cigarette smoke-induced changes in the murine vocal folds: a Raman spectroscopic observation. Analyst 2021; 145:7709-7717. [PMID: 32996925 DOI: 10.1039/d0an01570a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Raman spectroscopic methods are being projected as novel tools to study the early invisible molecular level changes in a label-free manner. In the present study, we have used Raman spectroscopy to explore the earliest biochemical changes in murine vocal folds in response to time-bound cigarette smoke exposure. Mice were exposed to cigarette smoke for 2 or 4-weeks through a customized smoke inhalation system. The larynx was collected and initial evaluations using standard methods of analysis such as histopathology and immunofluorescence was performed. Concurrent unstained sections were used for Raman imaging. Two common pathological features of vocal fold disorders including alterations in collagen content and epithelial hypercellularity, or hyperplasia, were observed. The mean spectra, principal component analysis, and Raman mapping also revealed differences in the collagen content and hypercellularity in the smoke exposed tissues. The differences in 2-week exposed tissues were found to be more prominent as compared to 4-week. This was attributed to adaptive responses and the already reported biphasic effects, which suggest that collagen synthesis is significantly reduced at higher cigarette smoke concentrations. Overall findings of the study are supportive of the prospective application of Raman imaging in monitoring changes due to cigarette smoke in the vocal folds.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head & Neck Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Easwaran M, Martinez JD, Ramirez DJ, Gall PA, Erickson-DiRenzo E. Short-term whole body cigarette smoke exposure induces regional differences in cellular response in the mouse larynx. Toxicol Rep 2021; 8:920-937. [PMID: 33996505 PMCID: PMC8099918 DOI: 10.1016/j.toxrep.2021.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/11/2021] [Accepted: 04/16/2021] [Indexed: 11/29/2022] Open
Abstract
Short-term CSE induced regional differences in murine laryngeal cellular responses. Basal cell hyperplasia accompanies adaptive cell proliferation in the vocal folds. Increased subglottic cell proliferation persists even after CS cessation. SEM revealed vocal fold microprojection damage with possible necrotic features. Subglandular acidic mucins decreased and neutral mucins increased post-CSE.
The larynx is an essential organ in the respiratory tract and necessary for airway protection, respiration, and phonation. Cigarette smoking is a significant risk factor associated with benign and malignant laryngeal diseases. Despite this association, the underlying mechanisms by which cigarette smoke (CS) drives disease development are not well elucidated. In the current study, we developed a short-term murine whole body inhalation model to evaluate the first CS-induced cellular responses in the glottic [i.e. vocal fold (VF)] and subglottic regions of the larynx. Specifically, we investigated epithelial cell proliferation, cell death, surface topography, and mucus production, at various time points (1 day, 5 days, 10 days) after ∼ 2 h exposure to 3R4F cigarettes (Delivered dose: 5.6968 mg/kg per cigarette) and following cessation for 5 days after a 5 day CS exposure (CSE). CSE elevated levels of BrdU labeled proliferative cells and p63 labeled epithelial basal cells on day 1 in the VF. CSE increased proliferative cells in the subglottis at days 5, 10 and following cessation in the subglottis. Cleaved caspase-3 apoptotic activity was absent in VF at all time points and increased at day 1 in the subglottis. Evaluation of the VF surface by scanning electron microscopy (SEM) revealed significant epithelial microprojection damage at day 10 and early signs of necrosis at days 5 and 10 post-CSE. SEM visualizations additionally indicated the presence of deformed cilia at days 5 and 10 after CSE and post-cessation in the respiratory epithelium lined subglottis. In terms of mucin content, the impact of short-term CSE was observed only at day 10, with decreasing acidic mucin levels and increasing neutral mucin levels. Overall, these findings reveal regional differences in murine laryngeal cellular responses following short-term CSE and provide insight into potential mechanisms underlying CS-induced laryngeal disease development.
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Key Words
- AB/PAS, Alcian blue/Periodic acid Schiff
- BLOQ, below limits of quantitation
- BSA, bovine serum albumin
- BrdU, 5-bromo-2′-deoxyuridine
- CBF, ciliary beat frequency
- CC3, cleaved caspase-3
- CO, Carbon monoxide
- CS, cigarette smoke
- CSE, cigarette smoke exposure
- Cell death
- Cell proliferation
- Cigarette smoke
- DAB, 3,3′-diaminobenzidine
- FTC/ISO, Federal Trade Commission/International Standard Organization
- GSD, geometric standard deviation
- H&E, Hematoxylin and Eosin
- HIER, heat-induced antigen retrieval
- HPF, high power field
- MCC, mucociliary clearance
- MMAD, Mass median aerodynamic diameter
- Mucus production
- Murine larynx
- NMR, nicotine metabolite ratio
- OECD, organization for economic co-operation and development
- PAHs, polycyclic aromatic hydrocarbons
- RE, respiratory epithelium
- REV, reversibility
- ROS, reactive oxygen species
- SCIREQ, Scientific Respiratory Equipment Inc
- SEM, scanning electron microscopy
- SSE, stratified squamous epithelium
- SWGTOX, Scientific Working Group for Forensic Toxicology
- Surface topography
- TBST, tris-buffered saline-tween 20
- TPM, total particulate matter
- TSNA, tobacco-specific nitrosamines
- UPLC-MS/MS, ultra-performance liquid chromatography-tandem mass spectrometer
- VF, vocal fold
- VSC, veterinary service center
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Affiliation(s)
- Meena Easwaran
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Joshua D Martinez
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel J Ramirez
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Phillip A Gall
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
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Erickson-DiRenzo E, Kuijper FM, Barbosa DAN, Lim EA, Lin PT, Lising MA, Huang Y, Sung CK, Halpern CH. Multiparametric laryngeal assessment of the effect of thalamic deep brain stimulation on essential vocal tremor. Parkinsonism Relat Disord 2020; 81:106-112. [PMID: 33120071 DOI: 10.1016/j.parkreldis.2020.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVE EVT is a refractory voice disorder that significantly affects quality of life. This work aims to conduct a multiparametric assessment of the effect of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) on essential vocal tremor (EVT) and investigate the relation between DBS lead location and EVT outcomes. METHODS Nine participants underwent DBS for essential tremor and were diagnosed with co-occurring EVT in this prospective cohort study. Objective measurements including acoustic evaluation of vocal fundamental frequency (F0) and intensity modulation and subjective measurements including physiologic evaluation of the oscillatory movement of the laryngeal muscles and vocal tract and perceptual ratings of tremor severity were collected PRE and POST DBS. Finally, we investigated the relation between DBS lead location and EVT outcomes. RESULTS Acoustic modulations of F0 and intensity were significantly improved POST DBS. Physiologic assessment showed a POST DBS reduction of oscillatory movement in the laryngeal muscles and vocal tract, but not significantly. Listener and participant perception, of EVT severity was also significantly reduced. Finally, our results indicate better EVT control with increased distance to midline of left VIM thalamic stimulation. CONCLUSIONS By employing a battery of objective and subjective measures, our study supports the benefit of DBS for the treatment of EVT and specifies the acoustic and physiologic mechanisms that mediate its positive effect. We further provide preliminary results on the relation between lead location and EVT outcomes, laying the foundation for future studies to clarify the optimal DBS target for the treatment of EVT.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Fiene Marie Kuijper
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Daniel A N Barbosa
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Erika A Lim
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Peter T Lin
- Valley Parkinson Clinic, 800 Pollard Road, Suite C-30, Los Gatos, CA, USA
| | - Melanie A Lising
- Department of Neurology, Stanford University School of Medicine, Stanford, CA, USA
| | - Yuhao Huang
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - C Kwang Sung
- Department of Otolaryngology-Head & Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Casey H Halpern
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
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Erickson-DiRenzo E, Sung CK, Ho AL, Halpern CH. Intraoperative Evaluation of Essential Vocal Tremor in Deep Brain Stimulation Surgery. Am J Speech Lang Pathol 2020; 29:851-863. [PMID: 32073285 DOI: 10.1044/2019_ajslp-19-00079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Purpose Essential vocal tremor (EVT) is a prevalent and difficult-to-manage voice disorder. There is evidence that deep brain stimulation (DBS) of the ventral intermediate nucleus (Vim) of the thalamus may be beneficial for treating EVT. The objective of this preliminary investigation was to conduct intraoperative voice assessments during Vim-DBS implantation in order to evaluate immediate voice outcomes in medication-refractory essential tremor patients with co-occurring EVT. Method Seven adult subjects diagnosed with EVT undergoing Vim-DBS surgery participated in this investigation. Voice samples of sustained vowels were collected by a speech-language pathologist preoperatively and intraoperatively, immediately following Vim-DBS electrode placement. Voice evaluation included objective acoustic assessment of the rate and extent of EVT fundamental frequency and intensity modulation and subjective perceptual ratings of EVT severity. Results The rate of intensity modulation, extent of fundamental frequency modulation, and perceptual rating of EVT severity were significantly reduced intraoperatively as compared to preoperatively. Moderate, positive correlations were appreciated between a subset of acoustic measures and perceptual severity ratings. Conclusions The results of this study demonstrate a speech-language pathologist can conduct intra-operative evaluation of EVT during DBS surgery. Using a noninvasive, simple acoustic recording method, we were able to supplement perceptual subjective observation with objective assessment and demonstrate immediate, intraoperative improvements in EVT. The findings of this analysis inform the added value of intraoperative voice evaluation in Vim-DBS patients and contribute to the growing body of literature seeking to evaluate the efficacy of DBS as a treatment for EVT.
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Affiliation(s)
| | - C Kwang Sung
- Department of Otolaryngology-Head & Neck Surgery, School of Medicine, Stanford University, CA
| | - Allen L Ho
- Department of Neurosurgery, School of Medicine, Stanford University, CA
| | - Casey H Halpern
- Department of Neurosurgery, School of Medicine, Stanford University, CA
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Baird BJ, Mokhtari TE, Sung CK, Erickson-DiRenzo E. A Preliminary Study of Vocal Health Among Collegiate A Cappella Singers. J Voice 2020; 34:486.e1-486.e11. [DOI: 10.1016/j.jvoice.2018.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 09/30/2018] [Accepted: 10/01/2018] [Indexed: 11/17/2022]
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Santa Maria C, Sung CK, Baird BJ, Erickson-DiRenzo E. Vocal Hygiene in Collegiate Singers-Does Formal Training Relate to Practices? J Voice 2020; 35:859-868. [PMID: 32362576 DOI: 10.1016/j.jvoice.2020.03.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/13/2020] [Accepted: 03/18/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Vocal hygiene is vitally important for protecting vocal quality and promoting vocal longevity. It includes adequate hydration, avoidance of environmental irritants, and refraining from phonotraumatic behaviors such as screaming, excessive talking, and throat clearing. Formal singing training in addition to enhancing singing techniques, is also assumed to promote good vocal hygiene. Consequently, we investigated whether collegiate singers with formal training are more likely to practice good vocal hygiene habits than untrained collegiate singers. METHODS We completed a prospective cohort study, where collegiate singers at Stanford University were voluntarily enrolled in an annual vocal health clinic. Full laryngeal exams were performed and demographic information, formal vocal training status, and information on vocal hygiene habits were obtained through questionnaires. The results were then analyzed by grouping singers as "untrained" if less than 1 year of formal training, and "trained" if greater than a year. RESULTS A total of 82 singers were included for analysis, with 49 (59.8%) having greater than one year of formal training. Trained singers were more likely to employ a primary musical singing style of classical or operatic singing compared to untrained singers who were more likely to utilize "R&B" (P < 0.001). No significant differences were found between groups for hydration practices (P = 0.20), caffeine consumption (P = 0.73), warm up practices (P = 0.08), and phonotraumatic behaviors. Alcohol consumption, smoking tobacco, marijuana, e-cigarette usage was similar between groups. Overall, 11% of our sample reported intermittent less than daily marijuana use, with one singer reporting daily consumption. None of the singers in this sample used e-cigarettes. These rates are noticeably lower than the agematched United States population. Perceptions of cigarettes, marijuana, electronic cigarettes, alcohol, and caffeine were also the same between groups, with the vast majority of singers perceiving these agents as harmful to the voice (64%-100% depending on the agent). No laryngeal pathology was identified during laryngeal examination of any singers. CONCLUSIONS Vocal hygiene habits are similar between trained and untrained collegiate singers. This likely relates to a desire for vocal longevity irrespective of prior training. This may dispel the long-held assumption that formal training was necessary to develop good vocal habits. We do however, present a very homogenous, highly educated sample of collegiate singers from Stanford University, having significantly less at-risk behavior than their aged-matched counterparts in the general US population. A lack of laryngeal pathology despite extensive vocal demands may also be reflective of good vocal hygiene habits.
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Affiliation(s)
- Chloe Santa Maria
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - Chih-Kwang Sung
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California
| | - Brandon J Baird
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California; Department of Surgery - Section of Otolaryngology - Head and Neck Surgery, University of Chicago, Chicago, Illinois
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology - Head and Neck Surgery, Stanford University School of Medicine, Stanford, California.
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Ayoub N, Kearney A, Sayyid ZN, Erickson-DiRenzo E, Jeffrey C, Hwang PH. Nasal Symptoms Following Laryngectomy: A Cross-sectional Analysis. Am J Rhinol Allergy 2020; 34:388-393. [PMID: 31964149 DOI: 10.1177/1945892420901631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background After total laryngectomy, the severe reduction in nasal airflow alters the function and physiology of the nasal cavity. These anatomic and physiologic changes may in turn impact sinonasal quality of life. Objective This study sought to characterize the degree of postoperative sinonasal symptoms experienced by laryngectomees. Methods Two groups of subjects were recruited in this cross-sectional analysis: patients who previously underwent laryngectomy with or without chemoradiation for laryngeal or hypopharyngeal cancer and a comparison group treated with radiation but not laryngectomy. Patients underwent assessment of sinonasal symptoms using the Reflective Total Nasal Symptom Score (rTNSS), 22-item Sinonasal Outcome Test (SNOT-22), and visual analog scales (VASs). Patients also underwent nasal endoscopy recorded and graded by blinded reviewers using the Modified Lund–Kennedy (MLK) scale. Results Thirty-six laryngectomees and 12 controls were enrolled. The total SNOT-22 was similar between the 2 groups (27.3 vs 20.3, P = .16), but the laryngectomy cohort had higher rhinologic ( P < .01), extranasal ( P = .01), and ear/face ( P = .01) subdomain scores. VAS scores were worse in the laryngectomy group for nasal congestion ( P < .01), rhinorrhea ( P < .01), postnasal drip ( P < .01), and smell ( P < .01) but not for nasal fullness ( P = .11). rTNSS (4.7 vs 2.8, P = .04) and MLK scores (2.8 vs 0.8, P < .01) were higher in the laryngectomy group. In addition, 44% and 83% of patients in the laryngectomy and nonlaryngectomy groups, respectively, subjectively reported well-controlled nasal symptoms. Conclusion Laryngectomees are likely to experience a higher degree of subjective and objective nasal disease than nonlaryngectomized patients. Postlaryngectomy nasal dysfunction may be an important aspect of quality of life impairment in the laryngectomee population.
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Affiliation(s)
- Noel Ayoub
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California
| | - Ann Kearney
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California
| | - Zahra N Sayyid
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California
| | - Elizabeth Erickson-DiRenzo
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California
| | - Caroline Jeffrey
- Division of Otolaryngology-Head and Neck Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Peter H Hwang
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, Stanford University, Stanford, California
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Erickson-DiRenzo E, Leydon C, Thibeault SL. Methodology for the establishment of primary porcine vocal fold epithelial cell cultures. Laryngoscope 2019; 129:E355-E364. [PMID: 30848488 DOI: 10.1002/lary.27909] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/04/2019] [Accepted: 02/12/2019] [Indexed: 01/10/2023]
Abstract
OBJECTIVE A current lack of methods for epithelial cell culture significantly hinders our understanding of the role of the epithelial and mucus barriers in vocal fold health and disease. Our first objective was to establish reproducible techniques for the isolation and culture of primary porcine vocal fold epithelial cells. Our second objective was to evaluate the functional significance of cell cultures using an in vitro exposure to an inflammatory cytokine. METHODS Epithelial cells were isolated from porcine vocal folds and expanded in culture. Characterization of cultures was completed by immunostaining with markers for pan-cytokeratin (epithelial cells), vimentin (stromal cells), von Willebrand factor (endothelial cell), and MUC1 and MUC4 (mucin) glycoproteins. Established epithelial cell cultures were then exposed to the inflammatory cytokine tumor necrosis factor alpha (TNF-α) for 24-hours, and transcript expression of MUC1 and MUC4 was evaluated. RESULTS Reproducible, porcine vocal fold epithelial cell cultures, demonstrating cobblestone appearance characteristic of the typical morphology of epithelial cell cultures were created. Cells showed positive staining for pan-cytokeratin with limited expression of vimentin and von Willebrand factor. Epithelial cells also expressed MUC1 and MUC4. TNF-α significantly increased transcript expression of MUC4. CONCLUSION Here, we present the first report of successful culture of primary porcine vocal fold epithelial cells. Cultures will provide researchers with a valuable new in vitro tool to investigate vocal fold epithelium and mucus as well as the effects of common challenges, including inflammatory cytokines, on these barriers. LEVEL OF EVIDENCE NA Laryngoscope, 129:E355-E364, 2019.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Madison, Wisconsin, U.S.A
| | - Ciara Leydon
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Madison, Wisconsin, U.S.A
| | - Susan L Thibeault
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Madison, Wisconsin, U.S.A
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Erickson-DiRenzo E, Enos G, Thibeault SL. Early Cellular Response to Radiation in Human Vocal Fold Fibroblasts. Ann Otol Rhinol Laryngol 2015; 125:425-32. [PMID: 26553661 DOI: 10.1177/0003489415615140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Radiation therapy is a common treatment strategy for laryngeal carcinoma. However, radiation is not without adverse side effects, especially toward healthy vocal fold tissue, which can lead to long-term impairments in vocal function. The objective of this preliminary study was to investigate early responses of healthy human vocal fold fibroblasts (VFF) to radiation. METHODS VFF were exposed to a single or fractionated dose radiation scheme. Nonradiated VFF served as controls. Morphology of radiated and control VFF was subjectively examined. Quantitative polymerase chain reaction was used to evaluate the effect of radiation on extracellular matrix and inflammatory-related genes. VFF viability was investigated using a LIVE/DEAD and clonogenic assay. RESULTS Single or fractioned dose radiated VFF were morphologically indistinguishable from control VFF. No significant differences in gene expression were observed following either radiation scheme and as compared to controls. Clonogenic assay revealed reduced VFF viability following the fractionated but not single dose scheme. No changes in viability were detected using the LIVE/DEAD assay. CONCLUSIONS We present one of the first investigations to evaluate early responses of healthy VFF to radiation. Findings will contribute to a growing body of literature seeking to elucidate the biological mechanisms underlying voice changes following radiation therapy for laryngeal carcinoma.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Otolaryngology- Head & Neck Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - Gabrielle Enos
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Wisconsin, USA
| | - Susan L Thibeault
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Wisconsin, USA
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Erickson-DiRenzo E, Sivasankar MP, Thibeault SL. Utility of cell viability assays for use with ex vivo vocal fold epithelial tissue. Laryngoscope 2014; 125:E180-5. [PMID: 25511412 DOI: 10.1002/lary.25100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2014] [Indexed: 11/06/2022]
Abstract
OBJECTIVES/HYPOTHESIS Ex vivo models are routinely used to investigate the barrier function of the vocal fold epithelium. However, there are limited reports on assays that can be used to investigate the effect of clinically relevant challenges on vocal fold epithelial tissue viability. Our objective was to determine the utility of two assays routinely used in cell culture-a cellular metabolic activity assay and a cell membrane integrity assay-to investigate the viability of ex vivo porcine vocal fold epithelium. STUDY DESIGN Prospective, ex vivo animal study. METHODS Porcine vocal folds were exposed to acrolein, hydrochloric acid, or hydrogen peroxide challenge. An untreated, sham challenge was included as a control. Assays including metabolic activity, cell membrane integrity, and histology were used to determine whether challenges reduced epithelial viability as compared to sham. RESULTS Cell membrane integrity and metabolic activity assays detected reductions in viability following hydrochloric acid and hydrogen peroxide challenges but not acrolein challenge as compared to sham. No challenge produced significant changes in epithelial appearance as evidenced by light microscopy. CONCLUSIONS Metabolic activity and cell membrane integrity assays are valuable tools that can be used to evaluate the viability of ex vivo vocal fold epithelial tissue following clinically relevant challenges. As viability is reduced, the ability of epithelial tissue to maintain its barrier function is compromised. Accurate assessment of viability may provide us clues into understanding mechanisms underlying vocal fold epithelial injury and disease. LEVEL OF EVIDENCE NA Laryngoscope, 125:E180-E185, 2015.
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Affiliation(s)
- Elizabeth Erickson-DiRenzo
- Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, University of Wisconsin-Madison, Madison, Wisconsin
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