Adoption and Utilization of Heat and Moisture Exchangers (HMEs) in the Tracheostomy Patient.

OBJECTIVE: Management of tracheostomized patients typically involves a conventional external humidification system (CEHS). CEHS are noisy, negatively impact patient mobility, and increases costs. Additionally, they prevent phonation and the ability to cough. Alternatively, heat and moisture exchange (HME) devices have been used in laryngectomized patients. We present an institutional quality improvement project exploring the use and efficacy of an HME device following tracheostomy. METHODS: Health care professionals and stakeholders from multiple disciplines were identified: otolaryngology, nursing, administration, case management, and speech-language pathology. The focus was on an otolaryngology acute care nursing unit. Protocols for product acquisition, nursing education, care flowcharts, and discharge planning were established. Efficacy was assessed by tracking patient pulmonary status, nursing notes, and questionnaires. RESULTS: Seventy-one tracheostomized patients were enrolled. Two patients (2.8%) were unable to tolerate the HME. There were no complications from mucous plugging or respiratory distress. Eighty-nine percent of nursing staff surveyed preferred the use of an HME device over CEHS, particularly for ease of patient mobility. Additional favorable findings were patient satisfaction, cost savings, reduced noise, communication, and ease of discharge education and planning. DISCUSSION: Replacing CEHS with HMEs provides distinct advantages, with a positive impact on patients, family members, and health care personnel. Resistance to changing from the traditional standard of care was alleviated with education, focused training, and positive outcomes. IMPLICATIONS FOR PRACTICE: These data indicate that an HME device is safe and offers advantages to both patients and nurses over traditional CEHS.

Interferon-γ Treatment of Human Laryngotracheal Stenosis-Derived Fibroblasts.

Importance: Laryngotracheal stenosis (LTS) is a fibroproliferative disorder of the glottis, subglottis, and trachea. In models of fibrosis from other organ systems, the CD4+ T-cell response has been shown to regulate extracellular matrix deposition. Specifically, helper T cell 2 (TH2) promotes fibrosis, whereas TH1 and associated cytokines have been shown to be antifibrotic. However, this antifibrotic effect of the TH1 response has not been demonstrated in LTS. Objective: To determine whether the TH1 cytokine interferon-γ inhibits the function of LTS-derived fibroblasts in vitro. Design, Setting, and Participants: This in vitro controlled study included 6 patients with iatrogenic LTS undergoing routine surgical subglottic and tracheal dilation at a single institution. Fibroblasts were isolated from biopsy specimens of laryngotracheal scar and normal-appearing trachea. The presence of fibroblasts was confirmed by an immunohistochemical analysis. Laryngotracheal stenosis-derived fibroblasts were treated with interferon-γ and compared with untreated controls (2 sets of untreated, LTS-derived fibroblasts [media did not contain interferon-γ]) and normal airway fibroblasts (fibroblasts isolated from normal trachea). Data were collected from August 2015 through June 2016. Interventions: Treatment with interferon-γ, 10 ng/mL. Main Outcomes and Measures: Cellular proliferation, fibrosis gene expression (using quantitative reverse transcription polymerase chain reaction analysis), soluble collagen, and cellular histologic features were assessed. Results: Among the 6 patients (6 women; mean [SD] age, 38.3 [17.2] years), LTS-derived fibroblast proliferation was reduced in patients who received interferon-γ treatment compared with untreated controls on days 3 (mean difference, -6515 cells; 95% CI, -10 630 to -2600 cells) to 6 (mean difference, -47 521 cells; 95% CI, -81 285 to -13 757 cells). Interferon-γ treatment reduced collagen types I and III gene expression by 86% and 68%, respectively, and resulted in lower total collagen production (10.94 vs 14.89 µg/mL). In addition, interferon-γ treatment resulted in a 32% reduction in expression of transforming growth factor ß in LTS-derived fibroblasts. Conclusions and Relevance: Interferon-γ reduced proliferation, soluble collagen production, and collagen expression in LTS-derived fibroblasts while also reducing the expression of the profibrotic cytokine transforming growth factor ß. These findings suggest that therapeutics aimed at increasing interferon-γ and the TH1 response could attenuate LTS.

Quantification of Inflammatory Markers in Laryngotracheal Stenosis.

Objectives (1) Develop a novel method for serial assessment of gene and protein expression in laryngotracheal stenosis (LTS). (2) Assess cytokine expression and determine an immunophenotype in LTS. Study Design A matched comparison of endolaryngeal brush biopsy samples from laryngotracheal scar and normal airway. Setting Tertiary care hospital, 2015-2016. Methods Brush biopsy specimens of laryngotracheal scar and normal trachea were obtained from 17 patients with LTS at the time of operating room dilation and were used for protein and RNA extraction. Gene expression of the TH1 cytokine interferon γ (INF-γ), TH2 cytokine interleukin 4 (IL-4), transforming growth factor ß, and collagen 1 (Coll1) was quantified with quantitative real-time polymerase chain reaction. Cytokine analysis was performed with flow cytometry with a cytometric bead array. Results LTS specimens demonstrated a 13.68-fold increase in Coll1 gene expression versus normal ( P < .001, N = 17). Additionally, IL-4 gene expression showed a 3.76-fold increase ( P < .001, N = 17) in LTS scar. When stratified into iatrogenic LTS and idiopathic subglottic stenosis cohorts, INF-γ gene expression was significantly increased in idiopathic subglottic stenosis ( P = .011). Soluble cytokine measurements were below the limit of detection for reliable quantification and thus could not be assessed. Conclusions Brush biopsies from LTS samples can be successfully utilized for RNA extraction and demonstrate the expected increase in Coll1 gene expression associated with LTS. Preliminary gene expression suggests that abnormal collagen production may be mediated by the TH2 cytokine IL-4 and that increased INF-γ expression may represent a key difference between iatrogenic LTS and idiopathic subglottic stenosis. Further analysis of soluble cytokines is needed to confirm these findings.

Fibroblasts in Hypoxic Conditions Mimic Laryngotracheal Stenosis.

Objective To elucidate the role of hypoxia and inflammatory pathways in the pathogenesis of iatrogenic laryngotracheal stenosis (iLTS). Study Design (1) Examination of mucosal surface gene expression in human iLTS. (2) In vitro comparison of normal and scar laryngotracheal fibroblasts under normoxic and hypoxic conditions. Setting Tertiary care hospital in a research university (2012-2016). Subjects and Methods Brush biopsies were obtained from normal laryngotracheal tissue and scar in iLTS patients; gene expression was compared. Fibroblasts were isolated from normal and scarred trachea and grown in vitro in either a 1% O2 or normoxic environment. Cell growth and gene and protein expression were compared. Statistical analysis utilized a multilevel mixed effects model. Results Expression of IL-6 (fold change = 2.8, P < .01), myofibroblast marker αSMA (fold change = 3.0, P = .01), and MMP13 (fold change = 5.4, P = .02) was significantly increased in scar biopsy samples as compared to normal. Under hypoxic conditions in vitro, normal laryngotracheal fibroblasts proliferated significantly faster (n = 8, P < .01 each day). Expression of IL-6 (n = 8, fold change = 2.6, P < .01) increased significantly after 12 hours under hypoxia. Expression of αSMA (n = 8, fold change= 2.0, P = .03), COL1 (n = 8, fold change = 1.1, P = .03), and MMP13 (n = 8, fold change = 1.6, P = .01) increased significantly after 48 hours under hypoxia. Scar fibroblasts also proliferated significantly faster under hypoxic conditions but did not display the same expression profile. Conclusion Human iLTS scar has a myofibroblast phenotype. Under hypoxic conditions in vitro, normal laryngotracheal fibroblasts can transdifferentiate into a similar phenotype. These changes may be mediated by IL-6, a fibrosis-related cytokine.

Metabolic variations in normal and fibrotic human laryngotracheal-derived fibroblasts: A Warburg-like effect.

OBJECTIVES/HYPOTHESIS: Laryngotracheal stenosis (LTS) is a chronic fibrotic disease characterized by fibroblast proliferation, collagen deposition, and matrix remodeling in the lamina propria of the larynx and/or trachea. Current medical therapies are limited by a poor understanding of the effector cell's (fibroblasts) cellular biology and metabolism. The purpose of this study was to compare cellular proliferation, function, and metabolism between normal and LTS-derived fibroblasts in vitro. We hypothesize that LTS-derived fibroblasts will demonstrate aberrant behavior with faster proliferation, increased collagen production, and altered metabolic allocation compared with normal fibroblasts. STUDY DESIGN: In vitro comparative analysis. METHODS: Human biopsies of normal and iatrogenic LTS tissue (n = 7) were obtained, and fibroblasts were isolated and cultured in vitro. Cellular proliferation, cellular histology, gene expression, and metabolic analyses were performed. Statistical analyses comparing normal and scar-derived fibroblasts were performed. RESULTS: LTS fibroblast proliferation rate, cellular surface area, and collagen-1 expression were increased compared to normal fibroblasts. Cellular metabolic analysis of LTS-derived fibroblasts demonstrated reduced oxidative phosphorylation and increased glycolysis/oxidative phosphorylation ratio compared with normal fibroblasts. CONCLUSIONS: Human iatrogenic LTS-derived fibroblasts demonstrated aberrant behavior when compared with normal fibroblasts. A Warburg-like effect was revealed, suggesting human iatrogenic LTS fibroblasts drive their proliferation with aerobic glycolysis. The distinct metabolism suggests metabolic inhibitors could reduce fibroblast hyperplasia and hypertrophy in LTS and fibrosis in general. LEVEL OF EVIDENCE: NA Laryngoscope, 127:E107-E113, 2017.

Evaluation of Dyspnea Outcomes After Endoscopic Airway Surgery for Laryngotracheal Stenosis.

Importance: Endoscopic airway surgery is a frequently used procedure in the management of laryngotracheal stenosis (LTS); however, no established outcome measures are available to assess treatment response. Objective: To assess acoustics and aerodynamic measures and voice- and dyspnea-related quality of life (QOL) in adult patients with LTS who undergo endoscopic airway surgery. Design, Setting, and Participants: This case series compared preoperative measures and postoperative outcomes among adult patients who underwent endoscopic airway surgery for LTS from September 1, 2013, to September 30, 2015, at the tertiary care Johns Hopkins Voice Center. Patients were excluded if they did not undergo balloon dilation or if they had multilevel or glottic stenosis. The Phonatory Aerodynamic System was used to quantify laryngotracheal aerodynamic changes after surgery. Final follow-up was completed 2 to 6 weeks after surgery. Main Outcomes and Measures: The voice-related QOL instrument (V-RQOL), Dyspnea Index, and Clinical Chronic Obstructive Pulmonary Disease Questionnaire were completed before and after endoscopic surgery. Consensus auditory perceptual evaluation of voice, acoustic measurements, and aerodynamic outcomes were also assessed. Results: Fourteen patients (1 man and 13 women; mean [SD] age, 45.4 [4.3] years) were enrolled. The mean postoperative V-RQOL scores (n = 14) increased from 74.3 to 85.5 (mean of difference, 11.3; 95% CI, 2.2 to 20.3). The mean postoperative Dyspnea Index (n = 14) decreased from 26.9 to 6.6 (mean of difference, -20.3; 95% CI, -27.9 to -12.7); the mean postoperative Clinical Chronic Obstructive Pulmonary Disease Questionnaire scores (n = 9) decreased from 3.2 to 1.0 (mean of difference, -2.2; 95% CI, -3.4 to -0.9). Postoperative mean vital capacity (n = 14) increased from 2.5 to 3.1 L (mean of difference, 0.6 L; 95% CI, 0.3-1.0 L), whereas mean laryngeal resistance (n = 14) decreased from 73.9 to 46.4 cm H2O/L/s (mean of difference, -27.5 cm H2O/L/s; 95% CI, -44.8 to -10.3 cm H2O/L/s) postoperatively. Conclusions and Relevance: Patients demonstrate statistically and clinically significant improvement in dyspnea-related QOL, whereas a few patients showed a clinically significant improvement in V-RQOL. Dyspnea-related QOL outcomes should be added to airway surgeons' regular assessment of patients with LTS to measure treatment response and inform the decision to perform a second operation, whereas V-RQOL outcomes need additional prospective study with a larger sample size. The Phonatory Aerodynamic System is not an optimal method to quantify changes in laryngotracheal aerodynamics after intervention in LTS.

Voice Outcomes Following Posterior Cordotomy With Medial Arytenoidectomy in Patients With Bilateral Vocal Fold Immobility.

IMPORTANCE: Voice quality-of-life (VQOL) and perceptual voice outcomes are presumed to worsen following posterior cordotomy with medial arytenoidectomy for bilateral vocal fold immobility (BVFI); however, subjective and objective voice outcomes are not well studied in this postsurgical patient population. OBJECTIVE: To evaluate VQOL and perceptual voice outcomes following posterior cordotomy with medial arytenoidectomy for BVFI. DESIGN, SETTING, AND PARTICIPANTS: Retrospective medical record review of 15 patients with BVFI who underwent posterior cordotomy with medial arytenoidectomy at a tertiary care academic hospital from 2009 to 2012. INTERVENTIONS: Suspension microlaryngoscopy was performed to expose the posterior glottis. A posterior cordotomy and medial arytenoidectomy was performed anterior to the vocal process of the vocal fold in a medial to lateral fashion. MAIN OUTCOMES AND MEASURES: Data included age, sex, tracheostomy status, number of cordotomies, and voice outcomes. Voice-Related Quality of Life (VRQOL) and Consensus Auditory Perceptual Evaluation of Voice (CAPE-V) data were collected preoperatively and postoperatively surrounding a single procedure. Comparisons within a single group were performed with a paired t test. Statistical significance was determined at P ≤ .05. RESULTS: Eight patients (53%) were male, and 7 (47%) were female. Six patients (40%) required a tracheotomy at some point during treatment, 4 were successfully decannulated. For all 15 patients, the mean VRQOL scores improved 12 points from 47.33 to 59.33 after posterior cordotomy (P = .12). Mean CAPE-V overall severity scores in 13 patients increased 26 points after posterior cordotomy with medial arytenoidectomy from 38.12 to 62.77 (P = .01), indicating further deviance from normal. CONCLUSIONS AND RELEVANCE: To our knowledge, this is the first study to compare VQOL with perceptual voice outcomes following posterior cordotomy with medial arytenoidectomy in a series of patients with BVFI. Patients who underwent posterior cordotomy in this study had significantly reduced perceptual voice outcomes with unchanged VQOL. While postcordotomy patients have a dysphonia that is noticeable to voice professionals, most patients in this study subjectively felt as though their voice improved after surgery. Surgeons should be aware of these factors when counseling patients considering cordotomy for BVFI.

Dysregulated Macrophages Are Present in Bleomycin-Induced Murine Laryngotracheal Stenosis.

OBJECTIVE: To define the inflammatory cell infiltrate preceding fibrosis in a laryngotracheal stenosis (LTS) murine model. STUDY DESIGN: Prospective controlled murine study. SETTING: Laboratory. SUBJECTS AND METHODS: Chemomechanical injury mice (n = 44) sustained bleomycin-coated wire-brush injury to the laryngotracheal complex while mechanical injury controls (n = 42) underwent phosphate-buffered saline (PBS)-coated wire-brush injury. Mock surgery controls (n = 34) underwent anterior transcervical tracheal exposure only. Inflammatory and fibrosis protein and gene expression were assessed in each condition. Immunohistochemistry served as a secondary outcome. RESULTS: In chemomechanical injury mice, there was an upregulation of collagen I (P < .0001, P < .0001), Tgf-ß (P = .0023, P = .0008), and elastin (P < .0001, P < .0001) on day 7; acute inflammatory gene Il1ß (P = .0027, P = .0008) on day 1; and macrophage gene CD11b (P = .0026, P = .0033) on day 1 vs mechanical and mock controls, respectively. M1 marker inducible nitric oxide synthase (iNOS) expression decreased (P = .0014) while M2 marker Arg1 (P = .0002) increased on day 7 compared with mechanical controls. Flow cytometry demonstrated increased macrophages (P = .0058, day 4) and M1 macrophages (P = .0148, day 4; P = .0343, day 7; P = .0229, day 10) compared to mock controls. There were similarities between chemomechanical and mechanical injury mice with an increase in M2 macrophages at day 10 (P = .0196). CONCLUSIONS: The bleomycin-induced LTS mouse model demonstrated increased macrophages involved with the development of fibrosis. Macrophage immunophenotype suggested that dysregulated M2 macrophages have a role in abnormal laryngotracheal wound healing. These data delineate inflammatory cells and signaling pathways in LTS that may potentially be modulated to lessen fibroblast proliferation and collagen deposition.

Rapamycin inhibits human laryngotracheal stenosis-derived fibroblast proliferation, metabolism, and function in vitro.

OBJECTIVE: To determine if rapamycin inhibits the growth, function, and metabolism of human laryngotracheal stenosis (LTS)-derived fibroblasts. STUDY DESIGN: Controlled in vitro study. SETTING: Tertiary care hospital in a research university. SUBJECTS AND METHODS: Fibroblasts isolated from biopsies of 5 patients with laryngotracheal stenosis were cultured. Cell proliferation, histology, gene expression, and cellular metabolism of LTS-derived fibroblasts were assessed in 4 conditions: (1) fibroblast growth medium, (2) fibroblast growth medium with dimethylsulfoxide (DMSO), (3) fibroblast growth medium with 10(-10) M (low-dose) rapamycin dissolved in DMSO, and (4) fibroblast growth medium with 10(-9) M (high-dose) rapamycin dissolved in DMSO. RESULTS: The LTS fibroblast count and DNA concentration were reduced after treatment with high-dose rapamycin compared to DMSO (P = .0007) and normal (P = .0007) controls. Collagen I expression decreased after treatment with high-dose rapamycin versus control (P = .0051) and DMSO (P = .0093) controls. Maximal respiration decreased to 68.6 pMoles of oxygen/min/10 mg/protein from 96.9 for DMSO (P = .0002) and 97.0 for normal (P = .0022) controls. Adenosine triphosphate (ATP) production decreased to 66.8 pMoles from 88.1 for DMSO (P = .0006) and 83.3 for normal (P = .0003) controls. Basal respiration decreased to 78.6 pMoles from 108 for DMSO (P = .0002) and 101 for normal (P = .0014) controls. CONCLUSIONS: Rapamycin demonstrated an anti-fibroblast effect by significantly reducing the proliferation, metabolism, and collagen deposition of human LTS fibroblast in vitro. Rapamycin significantly decreased oxidative phosphorylation of LTS fibroblasts, suggesting at a potential mechanism for the reduced proliferation and differentiation. Furthermore, rapamycin's anti-fibroblast effects indicate a promising adjuvant therapy for the treatment of laryngotracheal stenosis.