Hillel, Alexander T.

Abstract The North American Airway Collaborative (NoAAC) previously published a 3‐year multi‐institutional prospective cohort study showing variation in treatment effectiveness between 3 primary surgical techniques for idiopathic subglottic stenosis (iSGS). In this report, we update these findings to include 5 years of data evaluating treatment effectiveness. Patients in the NoAAC cohort were re‐enrolled for 2 additional years and followed using the prespecified published protocol. Consistent with prior data, prospective observation of 487 iSGS patients for 5 years showed treatment effectiveness differed by modality. Cricotracheal resection maintained the lowest rate of recurrent operation (5%), followed by endoscopic resection with adjuvant medical therapy (30%) and endoscopic dilation (50%). These data support the initial observations and continue to provide value to providers and patients navigating longitudinal decision‐making. Level of evidence: 2—prospective cohort study.

Objectives: To examine whether social determinants of health (SDH) factors are associated with time to diagnosis, treatment selection, and time to recurrent surgical intervention in idiopathic subglottic stenosis (iSGS) patients. Methods: Adult patients with diagnosed iSGS were recruited prospectively (2015-2017) via clinical providers as part of the North American Airway Collaborative (NoAAC) and via an online iSGS support community on Facebook. Patient-specific SDH factors included highest educational attainment (self-reported), median household income (matched from home zip code via U.S. Census data), and number of close friends (self-reported) as a measure of social support. Main outcomes of interest were time to disease diagnosis (years from symptom onset), treatment selection (endoscopic dilation [ED] vs cricotracheal resection [CTR] vs endoscopic resection with adjuvant medical therapy [ERMT]), and time to recurrent surgical intervention (number of days from initial surgical procedure) as a surrogate for disease recurrence. Results: The total 810 participants were 98.5% female, 97.2% Caucasian, and had a median age of 50 years (IQR, 43-58). The cohort had a median household income of $62 307 (IQR, $50 345-$79 773), a median of 7 close friends (IQR, 4-10), and 64.7% of patients completed college or graduate school. Education, income, and number of friends were not associated with time to diagnosis via multivariable linear regression modeling. Univariable multinominal logistic regression demonstrated an association between education and income for selecting ED versus ERMT, but no associations were noted for CTR. No associations were noted for time to recurrent surgical procedure via Kaplan Meier modeling and Cox proportional hazards regression. Conclusions: Patient education, income, and social support were not associated with time to diagnosis or time to disease recurrence. This suggests additional patient, procedure, or disease-specific factors contribute to the observed variations in iSGS surgical outcomes.

ObjectivesIdiopathic subglottic stenosis (iSGS) is an inflammatory process leading to fibrosis and narrowing of the laryngotracheal airway. There is variability in patient response to surgical intervention, but the mechanisms underlying this variability are unknown. In this pilot study, we measure expression of candidate targets at the mucosal surface of the subglottis in iSGS patients. We aim to identify putative biomarkers for iSGS that provide insights into the molecular basis of disease progression, yield a gene signature for the disease, and/or predict a response to therapy.Study DesignIn vitro comparative study of human cells.MethodsLevels of candidate transcripts and proteins were measured in healthy and stenotic laryngotracheal tissue specimens taken from the mucosal surface in 16 iSGS patients undergoing endoscopic balloon dilation. Pre‐ and post‐operative pulmonary function test and patient reported voice and breathing outcomes were also assessed. Unsupervised clustering was used to define patient subgroups based on expression profile.ResultsPulmonary function and voice and breathing outcome metrics demonstrated significant post‐operative improvement. Transcript levels of αSMA, CCL2, COL1A1, COL3A1, FN1, IFNG, and TGFB1 and protein levels of CCL2, IFNG, and IL‐6 were significantly upregulated in stenotic as compared to healthy tissues. Marked heterogeneity was observed in the patterns of expression of candidate markers across individuals and tissue types. Patient subgroups defined by expression profile did not show a statistically significant difference in dilation interval.ConclusionPro‐inflammatory and pro‐fibrotic pathways are significantly upregulated along the mucosal surface of stenotic laryngotracheal tissues, and CCL2 and IFNG merit further investigation as potential iSGS biomarkers.Level of Evidence4 Laryngoscope, 131:342–349, 2021

The laryngotracheal region resides at the intersection between the heavily studied nasal cavity and lungs; however, examination of the microbiome in chronic inflammatory conditions of the subglottis and trachea remains scarce. To date, studies have focused on the microbiota of the vocal folds, or the glottis, for laryngeal carcinoma, as well as healthy larynges, benign vocal fold lesions, and larynges exposed to smoking and refluxate. In this study, we seek to examine the structure and composition of the microbial community in adult laryngotracheal stenosis of various etiologies. Due to the heterogeneity among the underlying pathogenesis mechanisms and clinical outcomes seen in laryngotracheal stenosis disease, we hypothesized that different microbial profiles will be detected among various stenosis etiology types. Understanding differences in the microbiota for subglottic stenosis subtypes may shed light upon etiology-specific biomarker identification and offer novel insights into management approaches for this debilitating disease.

ObjectiveLaryngotracheal stenosis (LTS) is resource‐intensive disease. The cost‐effectiveness of LTS treatments has not been adequately explored. We aimed to conduct a cost‐effectiveness analysis comparing open reconstruction (cricotracheal/tracheal resection [CTR/TR]) with endoscopic dilation in the treatment of LTS.Study DesignRetrospective cohort.SettingTertiary referral center (2013‐2017).Subjects and MethodsThirty‐four LTS patients were recruited. Annual costs were derived from the Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins University. Cost‐effectiveness analysis compared CTR/TR versus endoscopic dilation at a willingness‐to‐pay threshold of $50,000 per quality‐adjusted life year (QALY) over 5‐ and 10‐year time horizons. The incremental cost‐effectiveness ratio (ICER) was calculated with deterministic analysis and tested for sensitivity with univariate and probabilistic sensitivity analysis.ResultsMean LTS costs were $4080.09 (SE, $569.29) annually for related health care visits. The major risk factor for increased cost was etiology of stenosis. As compared with idiopathic patients, patients with intubation‐related stenosis had significantly higher annual costs ($5286.56 vs $2873.62, P =. 03). The cost of CTR/TR was $8583.91 (SE, $2263.22). Over a 5‐year time horizon, CTR/TR gained $896 per QALY over serial dilations and was cost‐effective. Over a 10‐year time horizon, CTR/TR dominated dilations with a lower cost and higher QALY.ConclusionThe cost of treatment for LTS is significant. Patients with intubation‐related stenosis have significantly higher annual costs than do idiopathic patients. CTR/TR contributes significantly to cost in LTS but is cost‐effective versus endoscopic dilations for appropriately selected patients over a 5‐ and 10‐year horizon.

Objectives/HypothesisIdiopathic subglottic stenosis (iSGS) is an unexplained obstruction involving the lower laryngeal and upper tracheal airway. Persistent mucosal inflammation is a hallmark of the disease. Epithelial microbiota dysbiosis is found in other chronic inflammatory mucosal diseases; however, the relationship between tracheal microbiota composition and iSGS is unknown.Given the critical role for host defense at mucosal barriers, we analyzed tissue specimens from iSGS patients for the presence of microbial pathogens.MethodsUtilizing 30 human iSGS, 20 intubation‐related tracheal stenosis (iLTS), and 20 healthy control specimens, we applied molecular, immunohistochemical, electron microscopic, immunologic, and Sanger‐sequencing techniques.ResultsWith unbiased culture‐independent nucleic acid, protein, and immunologic approaches, we demonstrate that Mycobacterium species are uniquely associated with iSGS. Phylogenetic analysis of the mycobacterial virulence factor rpoB suggests that, rather than Mycobacterium tuberculosis, a variant member of the Mycobacterium tuberculosis complex or a closely related novel mycobacterium is present in iSGS specimens.ConclusionThese studies identify a novel pathogenic role for established large airway bacteria and provide new targets for future therapeutic intervention.Level of EvidenceNA Laryngoscope, 127:179–185, 2017

Objectives/HypothesisIdiopathic subglottic stenosis (iSGS) is a rare and devastating extrathoracic obstruction involving the lower laryngeal and upper tracheal airway. It arises without known antecedent injury or associated disease process. Persistent mucosal inflammation and a localized fibrotic response are hallmarks of the disease. Despite the initial clinical description of iSGS more than 40 year ago, there have been no substantive investigations into the pathogenesis of this enigmatic and progressive airway obstruction. In these studies, we present the initial characterization of the molecular pathogenesis underlying the fibrosing phenotype of iSGS.MethodsUtilizing 20 human iSGS and healthy control specimens, we applied histologic, immunohistochemical, molecular, and immunologic techniques.ResultsWe demonstrate significant activation of the canonical IL‐23/IL‐17A pathway in the tracheal mucosa of iSGS patients, as well as identify γδ T cells as the primary cellular source of IL‐17A.ConclusionOur results suggest that aberrant mucosal immune activation is a component in of the pathogenesis of iSGS. Most critically, our work offers new targets for future therapeutic intervention.Level of EvidenceNA Laryngoscope, 126:E356–E361, 2016

Objectives/Hypothesis Idiopathic subglottic stenosis (iSGS) is a rare and potentially life‐threatening disease marked by recurrent and progressive airway obstruction frequently requiring repeated surgery to stabilize the airway. Unknown etiology and low disease prevalence have limited the ability to characterize the natural history of iSGS and resulted in variability in surgical management. It is uncertain how this variation relates to clinical outcomes. Study Design Medical record abstraction. Methods Utilizing an international, multi‐institutional collaborative, we collected retrospective data on patient characteristics, treatment, and clinical outcomes. We investigated variation between and within open and endoscopic treatment approaches and assessed therapeutic outcomes; specifically, disease recurrence and need for tracheostomy at last follow‐up. Results Strikingly, 479 iSGS patients across 10 participating centers were nearly exclusively female (98%, 95% confidence interval [CI], 96.1–99.6), Caucasian (95%, 95% CI, 92.2–98.8), and otherwise healthy (mean age‐adjusted Charlson Comorbidity Index 1.5; 95% CI, 1.44–1.69). The patients presented at a mean age of 50 years (95% CI, 48.8–51.1). A total of 80.2% were managed endoscopically, whereas 19.8% underwent open reconstruction. Endoscopic surgery had a significantly higher rate of disease recurrence than the open approach (chi 2 = 4.09, P = 0.043). Tracheostomy was avoided in 97% of patients irrespective of surgical approach (95% CI, 94.5–99.8). Interestingly, there were outliers in rates of disease recurrence between centers using similar treatment approaches. Conclusion Idiopathic subglottic stenosis patients are surprisingly homogeneous. The heterogeneity of treatment approaches and the observed outliers in disease recurrence rates between centers raises the potential for improved clinical outcomes through a detailed understanding of the processes of care. Level of Evidence 4. Laryngoscope , 126:1390–1396, 2016