Idiopathic subglottic stenosis: a review

Assessing the interrater and intrarater reliability of subglottic stenosis grading systems

BACKGROUND

Subglottic stenosis (SGS) is a condition leading to narrowing of the upper airway which can lead to dyspnea and life-threatening airway obstruction. Although other proposed grading systems exist, the Cotton Myer (CM) and percent stenosis systems are the most widespread in clinical practice. Despite this, the CM system has not yet been validated for visual assessment of SGS.

OBJECTIVE

To determine the interrater and intrarater reliability of the CM grading system among a cohort of physicians who manage patients with SGS.

METHODS

An online survey created with videos of tracheoscopies from 20 adult patients with subglotticstenosis (SGS) was sent individually to 9 expert physicians from various medical specialties, all of whom managed patients with SGS. Physicians were asked to view the 20 tracheoscopy videos and assess both the percent stenosis and Cotton Myer (CM) grade of each patient. After a period of 4 weeks, the physicians were sent the same survey of the 20 tracheoscopy videos. The interrater and intrarater reliability was calculated using the intraclass correlation coefficient (ICC), a measurement used to evaluate the reliability (the extent to which a measurement can be replicated) of two or more raters measuring the same subject.

RESULTS

Overall, CM and percent stenosis systems were found to have an ICC of 0.94 and 0.90 within the domain of interrater reliability, respectively, and ICC of 0.71 and 0.81 within the domain of intrarater reliability, respectively.

CONCLUSION

Our findings suggest that the CM and percent stenosis grading systems remain a valid clinical tool to measure and communicate the severity of airway obstruction in SGS.

Mapping quality of life after balloon dilatation in subglottic stenosis using Dyspnea index and Short Form Health Survey-36

PURPOSE

An accurate diagnosis and proper treatment plan are required to restore an adequate patent airway in fibrotic subglottic stenosis (SGS). Currently, the definitive treatment entails single-stage balloon dilatation with steroid injections. The primary aim was to evaluate successful airway restoration and general quality of life in cases with SGS in northern Sweden using robust patient reported outcomes.

METHODS

All participants with need of surgical treatment due to SGS that had been referred to the department of otorhinolaryngology, University Hospital of Umeå from September 2020 to August 2023 was included. Exclusion criteria included malignant, extrathoracic or cartilaginous cause, age < 18 years, or incompetent to sign consent documents. We assessed the patient-reported outcome measures pre- as well as 3 months postoperatively.

RESULTS

Of the 40 cases fulfilling the eligibility criteria's, 33 cases completed the Dyspnea index (DI) and the short form health survey (SF-36) pre- as well as 3 months post-operatively. Receiver operating characteristics showed significant improvement in DI as well as in SF 36 scores post-operatively.

CONCLUSIONS

Evaluation of balloon dilatation in SGS in this cohort follow-up analysis shows clear improvement in patient quality of life using robust PROM 3 months postoperatively, ensuring the use of a safe and well-tolerated procedure.

Effects of shape and structure of a new 3D-printed personalized bioresorbable tracheal stent on fit and biocompatibility in a rabbit model

To date, several types of airway stents are available to treat central airway obstructions. However, the ideal stent that can overcome anatomical, mechanical and microbiological issues is still awaited. In addition, therapeutic effect and self-elimination of these stents are desirable properties, which pose an additional challenge for development and manufacturing. We aimed to create a prototype bioresorbable tracheal stent with acceptable clinical tolerance, fit and biocompatibility, that could be tested in a rabbit model and in the future be further optimized to enable drug-elution and ensure local therapeutic effect. Twenty-one New Zealand White Rabbits received five different types of bioresorbable tracheal stents, 3D-printed from poly(D,L-lactide-co-ε-caprolactone) metacrylates. Various configurations were tested for their functionality and improved until the best performing prototype could undergo detailed in vivo assessment, regarding clinical tolerance, migration and biocompatibility. Previously tested types of 3D printed stents in our preliminary study required improvement due to several problems, mainly related to breakage, unreliable stability and/or migration within the trachea. Abandoned or refined pre-prototypes were not analyzed in a comparative way. The final best performing prototype stent (GSP2 (Group Stent Prototype 2), n = 8) allowed a transoral application mode and showed good clinical tolerance, minimal migration and acceptable biocompatibility. The good performance of stent type GSP2 was attributed to the helix-shaped surface structure, which was therefore regarded as a key-feature. This prototype stent offers the possibility for further research in a large animal model to confirm the promising data and assess other properties such as bioresorption.

Degrees of Inflammation in the Treatment of Subglottic Stenosis in a Rabbit Model: Histopathological Assessment of a Novel Bioabsorbable Ultra-high Ductility Magnesium Alloy Stent

OBJECTIVE

Utilizing a novel histopathological scoring system and subglottic stenosis (SGS) rabbit model, we aimed to compare degrees of inflammation and severity of narrowing in the subglottis between two minimally invasive therapeutic modalities: endoscopic balloon dilation (EBD) alone versus EBD with placement of a bioabsorbable ultra-high ductility magnesium (UHD-Mg) alloy stent.

METHODS

SGS was induced endoscopically via microsuspension laryngoscopy in 23 New Zealand white rabbits. The control group (n = 11) underwent EBD alone, the study arm (n = 12) underwent EBD with implantation of bioabsorbable UHD-Mg alloy stents. Rabbits were euthanized at 2-, 3-, and 6-weeks after SGS induction, coinciding with wound healing stages. Using Optical Coherence Tomography (OCT), cross-sectional areas of airways were compared to calculate the mean percentage of intraluminal area at sequential time points. A novel histopathological scoring system was used to analyze frozen sections of laryngotracheal complexes. The degree of inflammation was quantified by scoring changes in inflammatory cell infiltration, epithelial ulceration/metaplasia, subepithelial edema/fibrosis, and capillary number/dilation. Univariate analysis was utilized to analyze these markers.

RESULTS

We found rabbits implanted with the bioabsorbable UHD-Mg alloy stent had statistically significantly higher scores in categories of hyperplastic change (stents vs controls: 1.48 vs 0.46 p < 0.001), squamous metaplasia (22 vs 5 p < 0.001), and neutrophils/fibrin in lumen (31 vs 8, p < 0.001). Rabbits who received EBD alone had higher scores of subepithelial edema and fibrosis (2.70 vs 3.49, p < 0.0256). The stented rabbits demonstrated significantly increased mean percent stenosis by intraluminal mean area compared to controls at 2 weeks (88.56 vs 58.98, p = 0.032), however at all other time points there was no significant difference between intraluminal subglottic stenosis by mean percent stenosis area.

DISCUSSION

Rabbits with SGS treated with UHD-Mg alloy stents demonstrated histopathologic findings suggestive of lower levels of tracheal fibrosis. This could indicate a reduced tendency towards the development of stenosis when compared to EBD alone. There was not a difference in luminal size between stent and non-stented rabbits at the six-week end point. Histologically, however, overall the use of bioabsorbable UHD-Mg alloy stenting elicited a greater tissue response at the level of the superficial mucosa rather than fibrosis of the lamina propria seen in the stented rabbits. This suggests more favorable healing and less of a tendency towards fibrosis and stenosis even though there may not be a benefit from a luminal size standpoint during this early healing period. Compared to known complications of currently available non-bioabsorbable metal or silicone-based stents, this proof-of-concept investigation highlights the potential use of a novel biodegradable UHD-Mg stent as a therapeutic modality for pediatric SGS.

[Tracheobronchial involvement in relapsing polychondritis and differential diagnoses]

Relapsing polychondritis is a systemic auto-immune disease that mainly affects cartilage structures, progressing through inflammatory flare-ups between phases of remission and ultimately leading to deformation of the cartilages involved. In addition to characteristic damage of auricular or nasal cartilage, tracheobronchial and cardiac involvement are particularly severe, and can seriously alter the prognosis. Tracheobronchial lesions are assessed by means of a multimodal approach, including dynamic thoracic imaging, measurement of pulmonary function (with recent emphasis on pulse oscillometry), and mapping of tracheal lesions through flexible bronchoscopy. Diagnosis can be difficult in the absence of specific diagnostic tools, especially as there may exist a large number of differential diagnoses, particularly as regards inflammatory diseases. The prognosis has improved, due largely to upgraded interventional bronchoscopy techniques and the development of immunosuppressant drugs and targeted therapies, offering patients a number of treatment options.

[Idiopathic Subglottic Tracheal Stenosis]

Idiopathic subglottic stenosis is a circular scarred narrowing of the airway at the transition from the cricoid cartilage to the trachea. The stenosis is found radiologically and endoscopically at the level of the cricoid cartilage without involvement of the cricoid or tracheal cartilage itself. The disease practically only affects women between the ages of 20 and 60. The same clinical picture occurs in granulomatosis with polyangiitis and less frequently in other autoimmune diseases, where it requires systemic treatment. The clinical picture usually begins insidiously with coughing and sputum production and leads to dyspnoea and a restricted cough. As the course is insidious and the patients are otherwise healthy, the symptoms are often misinterpreted and the diagnosis is delayed. Treatment consists of local measures, ranging from dilatation and laser surgical resection, sometimes with local application of medication to inhibit the proliferation of new scar tissue, to laryngotracheal resection of varying degrees. The disease is located in the border area between the trachea and larynx and the patients are therefore treated by ENT medicine, pneumology and thoracic surgery.

Symptom-Free Intervals Following Laser Wedge Excision for Recurrent Idiopathic Subglottic Stenosis

OBJECTIVE

Analyze the duration of symptom-free intervals following laser wedge excision (LWE) for recurrent idiopathic subglottic stenosis (iSGS). Secondary aim includes evaluating the influence of patient-related or disease factors.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary center.

METHODS

Review of iSGS patients who underwent LWE between 2002 and 2021. LWE patients without prior airway surgery were labeled LWE primary (LWEP) and those with prior history of dilation were labeled LWE secondary (LWES). A conditional frailty repeated events model was used to analyze the median time to recurrence (MTR) for each nth recurrence. Secondary analysis included stratification by use of medical therapy and initial preoperative characteristics of scar (Myer-Cotton grade, distance between the glottis and superior-most aspect of scar, DGS; length of scar, DL).

RESULTS

Two hundred and ten iSGS patients underwent LWE (131 LWEP, 79 LWES). The proportion of patients experiencing at least 1, 3, 6, and 12 recurrences, respectively, was 68.0% (n = 143), 40.7% (n = 85), 20.0% (n = 42), and 5.2% (n = 11). There was exponential time-shortening from the 1st to 12th recurrence (P < .0001). While MTR was 4.1 years after the first LWE, this fell to 2.8, 1.7, 1.0, and 0.7 years for the 2nd, 3rd, 6th, and 12th recurrences. Furthermore, LWEP patients experienced longer MTR than LWES counterparts within the first 6 recurrences (P < .01). There was no significant relationship between intersurgical interval and medication adherence, DL, DGS, or grade for recurrences beyond the first (P = .207, P = .20, P = .43, P = .16).

CONCLUSION

Symptom-free intervals in iSGS shorten with each subsequent recurrence and LWE. The difference in MTR between LWEP and LWES groups was significant within the first 6 recurrences with LWEP having longer MTR.

LEVEL OF EVIDENCE: 3

An Ovine Model Yields Histology and Gene Expression Changes Consistent with Laryngotracheal Stenosis

OBJECTIVES

Animal models for laryngotracheal stenosis (LTS) are critical to understand underlying mechanisms and study new therapies. Current animal models for LTS are limited by small airway sizes compared to human. The objective of this study was to develop and validate a novel, large animal ovine model for LTS.

METHODS

Sheep underwent either bleomycin-coated polypropylene brush injury to the subglottis (n = 6) or airway stent placement (n = 2) via suspension microlaryngoscopy. Laryngotracheal complexes were harvested 4 weeks following injury or stent placement. For the airway injury group, biopsies (n = 3 at each site) were collected of tracheal scar and distal normal regions, and analyzed for fibrotic gene expression. Lamina propria (LP) thickness was compared between injured and normal areas of trachea.

RESULTS

No mortality occurred in sheep undergoing airway injury or stent placement. There was no migration of tracheal stents. After protocol optimization, LP thickness was significantly increased in injured trachea (Sheep #3: 529.0 vs. 850.8 um; Sheep #4: 933.0 vs. 1693.2 um; Sheep #5: 743.7 vs. 1378.4 um; Sheep #6: 305.7 vs. 2257.6 um). A significant 62-fold, 20-fold, 16-fold, 16-fold, and 9-fold change of COL1, COL3, COL5, FN1, and TGFB1 was observed in injured scar specimen relative to unaffected airway, respectively.

CONCLUSION

An ovine LTS model produces histologic and transcriptional changes consistent with fibrosis seen in human LTS. Airway stent placement in this model is safe and feasible. This large airway model is a reliable and reproducible method to assess the efficacy of novel LTS therapies prior to clinical translation.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2024.

Asymptomatic Subglottic Stenosis Discovered During Anesthesia Induction and Not Predicted by Preoperative Evaluation: A Case Report

Subglottic stenosis (SGS) can be asymptomatic in cases with slow-growing granulomas. In this study, we report a case of SGS discovered during tracheal intubation for anesthesia induction. A 74-year-old woman was scheduled for surgery under general anesthesia for a left humeral fracture. Resistance was observed when the tracheal tube passed through the glottis, stopping the tube from advancing. We placed a laryngeal mask (LMA) to secure her airway and examined it using a bronchial fiber to detect circumferential stenosis of the subglottis due to granulation. The airway was secured using an LMA instead of intubation, and the patient was successfully managed under anesthesia. Asymptomatic SGS is difficult to detect preoperatively, and anesthesiologists may encounter unexpected intubation issues. LMA is an important tool for an effective strategy to manage intubation difficulties.

A Comprehensive Flow Cytometry Panel for Analysis of Idiopathic Subglottic Stenosis

OBJECTIVE

To present a comprehensive flow cytometry panel for idiopathic subglottic stenosis (iSGS).

STUDY DESIGN

Controlled ex vivo cohort study.

SETTING

Tertiary care academic hospital in a metropolitan area.

METHODS

Flow cytometry and single-cell RNA sequencing were performed on 9 paired normal and scar tissue samples from iSGS patients. Flow cytometry was used to assess the presence of myeloid (CD11b, CD14, CD15, Siglec8), lymphoid (CD3, CD4, CD8, gamma delta [γδ], FOXP3), endothelial (CD31), fibroblast (CD90, SMA), and epithelial (CD326, CK5) markers.

RESULTS

On flow cytometry, iSGS scar is characterized by an increased presence of myeloid, lymphoid, endothelial, and fibroblast cell types, but a decreased presence of epithelial cells. In the myeloid lineage, iSGS scar samples demonstrated increased CD11b+ monocytes (P < .001), Siglec8+ eosinophils (P = .03), and CD14+ monocytes (P = .02). In the lymphoid lineage, iSGS scar demonstrated increased CD3+ T-cells (P < .001), CD4+ helper T-cells (P < .001), γδ+ T-cells (P < .001), and FOXP3+ regulatory T-cells (P = .002). iSGS scar exhibited specific increases in CD90+ (P = .04) and SMA+ (P < .001) fibroblasts but decreased CD326+ (E-cadherin) epithelial cells (P = .01) relative to normal samples.

CONCLUSION

We present a comprehensive flow cytometry panel for iSGS. This flow panel may serve as a common platform among airway scientists to elucidate the cellular mechanisms underpinning iSGS and other upper airway pathologies. Scar iSGS samples demonstrate a distinct cellular profile relative to normal iSGS specimens, exhibiting increased fibroblast, endothelial, and inflammatory cell types but decreased epithelium.

Does Idiopathic Subglottic Stenosis Length and Location Change with Serial Endoscopic Interventions?

OBJECTIVES/HYPOTHESIS

The aim was to assess changes in physical parameters of subglottic stenosis (SGS) following serial endoscopic surgical intervention.

STUDY DESIGN

This was a retrospective chart review.

METHODS

A retrospective review of 52 idiopathic subglottic stenosis (iSGS) patients undergoing multiple endoscopic (excision/dilation) procedures between 2014 and 2022 was completed. Parameters including proximal stenosis distance from the vocal process and total stenosis length collected intraoperatively were compared over serial treatments. Differences between patient variables affecting distances from the vocal process and mean stenosis length were statistically analyzed utilizing nonparametric estimators including the Mann Whitney U, Fisher exact, and linear regression models.

RESULTS

For the cohort of iSGS patients (N = 52), the mean age was 55.1 (±15.1). The patients were predominantly female (96.2%) and Caucasian (84.6%). Patients underwent an average of 3.4 (±1.3) endoscopic procedures for long-term treatment of iSGS (range: 1 to 5 procedures). Patients undergoing a total of two (2) total procedures within the data collection window demonstrated a statistically significant decrease in mean stenosis length between the first and second procedures (p = 0.014). Changes in distance of the stenosis from the glottis was not found to be statistically significant (p = 0.833). There was a statistically significant decrease in mean length of stenosis from the 1st to the 2nd procedure by approximately 0.11 cm (p = 0.0003). No additional statistically significant differences in stenosis length or location were detected.

CONCLUSIONS

Serial endoscopic excision/dilation procedures (the mainstay of iSGS surgical management) do not appear to significantly lengthen intraluminal stenosis nor change the distance of the stenosis from the glottis.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1769-1772, 2024.

Surgical Management of Airway Stenosis During Pregnancy: A Scoping Review

OBJECTIVE

There are several options for surgical management of subglottic stenosis, including endoscopic and open procedures. However, treatment algorithms, outcomes, and anesthetic management of subglottic stenosis during pregnancy are not well described.

DATA SOURCES

MEDLINE, EMBASE, and the Cochrane databases.

REVIEW METHODS

A scoping review of management of subglottic stenosis during pregnancy was performed, and then reported in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria consisted of those with subglottic or tracheal stenosis aged greater than 18 years, those in whom management was performed during pregnancy, and those who reported delivery related outcomes.

RESULTS

After systematic review and detailed search of 330 identified articles, 15 articles met inclusion criteria and were included in the final analysis. All studies were case reports or case series (level 4 evidence). This study identified 27 patients. The median age was 29 and the median gestational age at intervention was 28 weeks. Left lateral positioning and fetal heart rate monitoring were used in nearly every case. The most common intervention performed was endoscopic balloon dilation. In many cases, jet ventilation or transnasal humidified rapid insufflation ventilatory exchange was satisfactory for maintenance of the airway. Three women ultimately required tracheostomy prior to labor and delivery. There was no fetal death or complications reported in these studies, and all but one woman proceeded to deliver at term.

CONCLUSION

Endoscopic balloon dilation during pregnancy is safe and effective, resulting in optimized respiratory outcomes for the mother and safe delivery of the fetus. The third trimester appears to be safe for airway intervention. Laryngoscope, 134:1014-1022, 2024.

Anesthetic Management of Unanticipated Subglottic Stenosis in a Patient Undergoing Coronary Artery Bypass Graft Surgery

A 62-year-old female presented for a scheduled coronary artery bypass graft (CABG) and was found to have an unexpected subglottic stenosis during routine intubation. The case was aborted and six days later, the patient underwent lasering of the stenotic subglottic region and airway balloon dilation. In this case report, causes of subglottic stenosis and surgical/anesthetic management of the condition are discussed. The management of subglottic stenosis in this patient was complicated by concurrent severe coronary artery disease (CAD) involving the left main coronary artery and timing of airway surgery relative to interventions for her CAD. In situations of undiagnosed subglottic stenosis, anesthesiologists should be familiar with airway management based on the location and severity of the stenosis. Close multidisciplinary team management is required for patients who have other complex comorbidities.

Bibliometric and visualized analysis of scientific publications on subglottic stenosis based on web of science core collection

BACKGROUND

Subglottic Stenosis (SGS), with increasing numbers of studies, is the most specific and common clinical type of Laryngotracheal Stenosis (LTS). There is rapid publication turnover with newer management introduced and expanding research field. To our knowledge, there is no bibliometric analysis of SGS yet.

METHODS

In August 2022, we performed a thorough search in the Web of Science Core Collection database using the word "subglottic stenosis," and "SGS." The 580 articles were arranged based on correlation. The collected articles were then analyzed with an assessment of relevant factors. Meanwhile, we analyzed the top 100 most-cited articles on SGS.

RESULTS

The frequency of publication on SGS has increased substantially over time. The USA has contributed the most articles (n = 301). Vanderbilt University published most of the articles among other institutions (n = 18). Laryngoscope topped the list of journals and has published 89 SGS-related articles. Research hotspots shift from surgical treatment to conservative management.

CONCLUSIONS

The SGS-related literature has grown rapidly in recent years. This study represents the first bibliometric analysis of scientific articles on SGS. Areas to improve in SGS research can be identified after this analysis of the most impactful articles on this topic.

Idiopathic Subglottic Stenosis Is Associated With More Frequent and Abnormal Squamous Metaplasia

OBJECTIVES

Gain insights into the pathophysiology of idiopathic subglottic stenosis (iSGS) by investigating differences in transcriptome of subglottic mucosal tissue between patients with iSGS and controls, and between tracheal and subglottic tissue within patients.

METHODS

RNA sequencing was conducted on biopsied mucosal samples collected from subglottic and tracheal (in-patient control) regions in iSGS patients, and from subglottis in controls. The gene expression differences were validated on a protein level by (1) staining the tissue samples obtained from a second cohort of patients and controls; and (2) in vitro functional assays using primary subglottic epithelial cells from both iSGS patients and healthy donors.

RESULTS

We found 7 upregulated genes in the subglottic region of iSGS patients relative to both the tracheal mucosa and subglottic region of controls. A gene ontology enrichment analysis found that the epithelial cell differentiation and cornification pathways are significant, involving specifically 3 of the genes: involucrin (IVL), small proline rich protein 1B (SPRR1B), and keratin 16 (KRT16). Involvement of these pathways suggests squamous metaplasia of the epithelium. Histological analyses of epithelium in subglottic mucosal biopsies revealed squamous metaplasia in 41% of the samples from iSGS patients and in 25% from controls. Immunohistochemical evaluation of the samples presented with squamous epithelium revealed increased expression of the protein encoded by SPRR1B, hyperproliferative basal cells, shedding of apical layers, and accompanying lesions in iSGS compared to CTRL. Cultured primary subglottic epithelial cells from iSGS patients had higher proliferation rates compared to healthy donors and squamous metaplastic differentiation formed thinner epithelia with increased expression proteins encoded by INV, SPRR1B, and KRT16, suggesting intrinsic dysfunction of basal cells in iSGS.

CONCLUSIONS

Abnormal squamous differentiation of epithelial cells may contribute to the pathogenesis of iSGS. Patients having metaplastic epithelial phenotype may be sensitive to drugs that reverse it to a normal phenotype.

The Effect of an Increasing Subglottal Stenosis Constriction That Extends From the Vocal Folds to the Inferior Border of the Cricoid Cartilage

Acquired subglottal stenosis is an unpredicted complication that can occur in some patients who have undergone prolonged endotracheal intubation. It is a narrowing of the airway at the level of the cricoid cartilage that can restrict airflow and cause breathing difficulty. Stenosis is typically treated with endoscopic airway dilation, with some patients experiencing multiple recurrences. The study highlights the potential of computational fluid dynamics as a noninvasive method for monitoring subglottic stenosis, which can aid in early diagnosis and surgical planning. An anatomically accurate human laryngeal airway model was constructed from computerized tomography (CT) scans. The subglottis cross-sectional area was narrowed systematically using ≈10% decrements. A quadratic profile was used to interpolate the transformation of the airway geometry from its modified shape to the baseline geometry. The numerical results were validated by static pressure measurements conducted in a physical model. The results show that airway resistance follows a squared ratio that is inversely proportional to the size of the subglottal opening (R∝A-2). The study found that critical constriction occurs in the subglottal region at 70% stenosis (upper end of grade 2). Moreover, removing airway tissue below 40% stenosis during surgical intervention does not significantly decrease airway resistance.

Challenges in diagnosis and management of central airway obstruction: Case series

Central airway obstruction often presents with respiratory symptoms identical to those of common respiratory diseases. Diagnosis of central airway obstruction is challenging in clinical practice, especially misdiagnosed as asthma or chronic obstructive pulmonary disease in case of "normal" chest X-ray. Here, we reported five central airway obstruction cases: the first and fourth cases misdiagnosed as asthma, the second masquerading as chronic obstructive pulmonary disease exacerbation, the third diagnosed incorrectly with non-resolving pneumonia, and the fifth misdiagnosed as chronic obstructive pulmonary disease. We then analyzed diagnostic clues potentially useful to differentiate central airway obstruction from asthma/chronic obstructive pulmonary disease. A multidisciplinary approach to manage central airway obstruction is essential, particularly selecting judiciously the method of respiratory support due to the high risk of completed airway collapse or obstruction during interventional period.

Predictors of Clinical Outcomes in Adult Laryngotracheal Stenosis

OBJECTIVES

Sequelae of laryngotracheal stenosis (LTS) can be devastating, often necessitating tracheostomy. This study aims to describe the characteristics and outcomes of patients with LTS and identify risk factors for long-term tracheostomy dependence stratified by etiology.

METHODS

A retrospective chart review was performed on 215 patients diagnosed with LTS from 09/01/2011 to 12/31/2020. Patients were grouped based on the cause of LTS. Patient factors were compared to evaluate risk factors for long-term tracheostomy dependence.

RESULTS

Of the 215 patients, 129 (60%) were classified as iatrogenic, 41 (19%) idiopathic, 10 (4.7%) cancer treatment, 18 (8.3%) autoimmune, and 17 (8%) patients unknown. Idiopathic patients were significantly less likely to be tracheostomy-dependent compared with iatrogenic patients (p < 0.001) and cancer patients (p < 0.05). The mortality rate did not significantly differ among the categories (p = 0.1078). Significant improvement was seen after treatment, as the median percent of stenosis at presentation was 52.5%, and the median percent of stenosis at the most recent visit was 10% (p < 0.001). The autoimmune group received the most steroid injections (mean = 6.56; SD = 11.96). The idiopathic group had the longest surgery-free interval (mean = 30.8 months; SD = 27.7).

CONCLUSION

Iatrogenic and cancer patients were more likely to be tracheostomy-dependent. There was a significant improvement in percent and length of stenosis after treatment, with the idiopathic group having the longest surgery-free interval. Mortality risk did not differ among the different etiologies of LTS.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:257-263, 2024.

Dysfunctional Epithelial Barrier Is Characterized by Reduced E-Cadherin in Idiopathic Subglottic Stenosis

OBJECTIVES

To aim of the study was to characterize the molecular profile and functional phenotype of idiopathic subglottic stenosis (iSGS)-scar epithelium.

METHODS

Human tracheal biopsies from iSGS scar (n = 6) and matched non-scar (n = 6) regions were analyzed using single-cell RNA sequencing (scRNA-seq). Separate specimens were used for epithelial cell expansion in vitro to assess average growth rate and functional capabilities using transepithelial-electrical resistance (TEER), fluorescein isothiocyanate-dextran flux permeability assay, ciliary coverage, and cilia beating frequency (CBF). Finally, epithelial tight junction protein expression of cultured cells was quantified using immunoblot assay (n = 4) and immunofluorescence (n = 6).

RESULTS

scRNA-seq analysis revealed a decrease in goblet, ciliated, and basal epithelial cells in the scar iSGS cohort. Furthermore, mRNA expression of proteins E-cadherin, claudin-3, claudin-10, occludin, TJP1, and TJP2 was also reduced (p < 0.001) in scar epithelium. Functional assays demonstrated a decrease in TEER (paired 95% confidence interval [CI], 195.68-890.83 Ω × cm2 , p < 0.05), an increase in permeability (paired 95% CI, -6116.00 to -1401.99 RFU, p < 0.05), and reduced epithelial coverage (paired 95% CI, 0.1814-1.766, fold change p < 0.05) in iSGS-scar epithelium relative to normal controls. No difference in growth rate (p < 0.05) or CBF was found (paired 95% CI, -2.118 to 3.820 Hz, p > 0.05). Immunoblot assay (paired 95% CI, 0.0367-0.605, p < 0.05) and immunofluorescence (paired 95% CI, 13.748-59.191 mean grey value, p < 0.05) revealed E-cadherin reduction in iSGS-scar epithelium.

CONCLUSION

iSGS-scar epithelium has a dysfunctional barrier and reduced structural protein expression. These results are consistent with dysfunctional epithelium seen in other airway pathology. Further studies are warranted to delineate the causality of epithelial dysfunction on the downstream fibroinflammatory cascade in iSGS.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:374-381, 2024.

Curious Case of Pediatric One-Lung Ventilation with Two Endotracheal Tubes: A Case Report

ABSTRACT

One-lung ventilation is indicated during thoracic surgery for visualization and exposure of surgical site. It is achieved with bronchial blockers, double-lumen endobronchial tube, single-lumen endotracheal tubes and Univent tube for infants and children. Fibreoptic bronchoscope is required for placing and confirming the correct position of these tubes. We report a perioperative management of safe conduct of one lung ventilation for a 6-year child undergoing left lower lobe lobectomy through C-MAC video laryngoscope guided two single lumen tubes in limited resource settings where paediatric-sized fibreoptic bronchoscope is unavailable.

Predictors of response to endoscopic management of subglottic/tracheal stenosis in patients without tracheostomy

INTRODUCTION

Subglottic and tracheal stenosis (SGTS) in adults is an acquired or idiopathic condition that can lead to dyspnea, and even life-threatening airway obstruction. Endoscopic techniques have advanced and largely eclipsed open surgery, with open surgery now reserved for refractory cases (Hseu et al., 2013; Feinstein et al., 2017). Currently, there is no accepted guideline for the endoscopic treatment of SGTS. Thus, the aim of the present study is to examine the impact of various clinical and pathological characteristics on outcomes to endoscopic treatment in a cohort of SGTS patients.

DISCLOSURE

None of the authors have any financial or personal relationship that could cause a conflict of interest regarding this article.

METHODS

Retrospective chart review was performed for 41 patients presenting with SGS without a tracheostomy over a 4-year-period (2018-2022), within a single tertiary care center. Quantitative outcomes including number of dilation procedures undergone and need for open procedures were examined. The qualitative variables included a history of pulmonary disease, prior tracheostomy/tracheal resection, presence of tracheomalacia, granulation tissue, excessive dynamic airway collapse (EDAC), and etiology of idiopathic subglottic stenosis.

RESULTS

The presence of granulation tissue seen on tracheoscopy was associated with a higher number (4+) of dilation procedures (p = 0.01). A history of pulmonary disease (p = 0.037), the presence of tracheomalacia (p = 0.039), and the presence of granulation tissue (0.003) were all associated with a need for open procedures.

CONCLUSION

Patients with the presence of granulation tissue, tracheomalacia, and a history of pulmonary disease were more associated with more severe disease requiring either a higher number of endoscopic procedures or need for open procedures.

Idiopathic subglottic stenosis with an inguinal hernia in children: A case report

RATIONALE

Idiopathic subglottic stenosis is a fibrotic condition of unknown origin that results in blockage of the central airway in the subglottic region. It is widely acknowledged that subglottic stenosis is a relatively uncommon structural anomaly that is difficult to operate on and cure due to its anatomical location. Inguinal hernias are well-established to be prevalent in infants and youngsters. We present a case of subglottic stenosis in a child complicated with an inguinal hernia (IH).

PATIENT CONCERNS

A 7-year-old female was admitted to our hospital with a 1-month history of progressive bulging in the left lower quadrant of the abdomen. She complained of no stomach discomfort, distension, or dyspnea, but her family reports that the patient usually wheezes during moderate exertion and has no family history of asthma or lung illness. However, for unclear reasons, the infant experienced shortness of breath following training. A chest CT scan was unremarkable. Below the glottis, a membranous stenosis was discovered. The stenosis beneath the glottis was discovered using dynamic laryngoscopy.

DIAGNOSES

Idiopathic subglottic stenosis with an IH.

INTERVENTIONS

An otorhinolaryngologist employed a carbon dioxide laser to eliminate the subglottic stenosis. Following successful intubation by the anesthesiologist, pediatric surgeons performed laparoscopic high ligation of the hernial sac.

OUTCOMES

After 1 month, a repeat laryngoscopy revealed significant expansion of the subglottic stenosis, accounting for the improvement in respiratory symptoms.

LESSONS

The present case raises awareness that surgeons should be more vigilant about respiratory complications in patients with an IH. Early diagnosis and treatment of respiratory illnesses are critical for patients undergoing endotracheal intubation.

Characteristics of Idiopathic Subglottic Stenosis in the Elderly

OBJECTIVE

To compare characteristics of patients ≥65 years presenting with idiopathic subglottic stenosis (iSGS) to patients diagnosed at <65 years. We hypothesize that the groups have similar comorbidities and disease courses.

DATA SOURCES

Medical records of patients treated for iSGS at a tertiary care institution from January 2005-September 2022.

REVIEW METHODS

Patient demographics, time from symptom onset to diagnosis, medical history and comorbidities, and treatment modalities/intervals were recorded and analyzed. Characteristics of patients ≥65 and <65 years at presentation were compared using Chi-square analysis for non-numeric values and the Mann-Whitney U-test for numeric values.

RESULTS

One hundred seven patients with iSGS were identified and 16 (15%) were aged ≥65 years (mean age 72.6, 15 female) at presentation. These patients were compared to 91 patients aged <65 years (mean age = 47.6, 90 female). Patients ≥65 years had higher rates of type 2 diabetes mellitus (T2DM) (p = 0.004) and tobacco use (p = 0.004). There were no significant differences in body mass index, gastroesophageal reflux disease, hormone replacement therapy, time from symptom onset to presentation, or length of operative treatment intervals.

CONCLUSION

Patients ≥65 years with iSGS have higher rates of tobacco use, suggesting that alterations in wound healing may play a role in the development of iSGS in this age group. Although rates of T2DM were higher in the elderly group, clinical significance may be limited given the overall higher rate of diabetes mellitus in the elderly population.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:3075-3079, 2023.

How can we identify subglottic stenosis in patients with suspected obstructive disease?

PURPOSE

Subglottic stenosis, a rare condition of the upper airway, is frequently misdiagnosed as obstructive lung disease. The aim of this study was to investigate whether subglottic stenosis could be identified and distinguished from asthma and chronic obstructive pulmonary disease (COPD) using spirometry or the dyspnea index (DI).

METHODS

The study population included 43 patients with asthma, 31 patients with COPD and 50 patients with subglottic stenosis planned to undergo endoscopic intervention. All patients completed the DI and underwent dynamic spirometry registering both inspiratory and expiratory volumes and flows, including the expiratory disproportion index (EDI), the ratio of forced expiratory volume in 1 s to peak expiratory flow. One-way analysis of variance assessed the discrepancy of the variables among the study groups, and receiver operating curve (ROC) analysis determined the measurement with the best discriminatory power providing a cutoff value, maximizing both sensitivity and specificity.

RESULTS

The only statistically significant variables differing between all three groups were the EDI and the DI. The EDI showed an excellent area under the ROC curve (0.99, p < 0.001) with a cutoff value of 0.39 (98% sensitivity, 96% specificity), followed by DI (0.87, p < 0.001) with a cutoff score of > 25 (83% sensitivity and 78% specificity).

CONCLUSION

In patients with dyspnea of unknown cause, an increase in EDI should arouse a suspicion of extrathoracic airway obstruction, advocating for further evaluation with laryngotracheoscopy.

Characterizing the Macrophage Population in Patients With Idiopathic Subglottic Stenosis

OBJECTIVES

Idiopathic subglottic stenosis (iSGS) is characterized by progressive fibrosis and subglottic luminal narrowing. Currently, immune characterization has focused on T-cells; however, macrophages remain largely unexplored. The goals of this study are to characterize the transcriptome of iSGS macrophages and the fibrogenic nature of identifed biomarkers.

STUDY DESIGN

Bioinformatics and in vitro.

METHODS

Human tracheal biopsies from iSGS scar (n = 4), and matched non-scar (n = 4) regions were analyzed using single-cell RNA-seq (scRNA-seq). Immunofluorescence (IF) was performed on rapidly processed autopsies (RPA) and iSGS tracheal resections (n = 4) to co-localize S100A8/9 and CD11b. Collagen gene/protein expression was assessed in iSGS fibroblasts (n = 4) treated with protein S100A8/9 (1000 ng/ml). Macrophages were subclustered to identify distinct subpopulations.

RESULTS

scRNA-seq analysis revealed S100A8/S100A9 (fold change (FC) = 4.1/1.88, p < 0.001) as top differentially expressed genes in iSGS macrophages. IF exhibited increased CD11b+/S100A8/9+ cells in tracheal samples of iSGS versus RPA (26.75% ± 7.08 vs. 0.594% ± 0.974, n = 4, p = 0.029). iSGS fibroblasts treated with S100A8/9 demonstrated increased gene expression of COL1A1 (FC = 2.30 ± 0.45, p = 0.03, n = 4) and COL3A1 (FC = 2.44 ± 0.40, p = 0.03, n = 4). COL1A1 protein assays revealed an increase in the experimental group, albeit not significant, (p = 0.12, n = 4). Finally, macrophage sub clustering revealed one subpopulation as a predominant source of S100A8/S100A9 expression (FC = 7.94/5.47, p < 0.001).

CONCLUSIONS

S100A8/9 is a key biomarker in iSGS macrophages. Although S100A8/9 demonstrates profibrotic nature in vitro, the role of S100A8/9+ macrophages in vivo warrants further investigation.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:2308-2316, 2023.

Patient-specific airway stent using three-dimensional printing: a review

The primary function of an airway stent is to reestablish patency, impeding restenosis, supporting the tracheobronchial wall, or occluding fistulas. But stent-related complications are prevalent and can have devastating consequences. For this reason, stents are considered a last resort when there are no alternatives in treatment. Additionally, commercially available airway stents often poorly fit patients with complex airways, and they can cause various complications. At the end of the 20th century, three-dimensional (3D) printing technology was created. It has been transformative in healthcare and has been used in several applications. One of its first utilizations was the anatomical modeling of body structures that helps preoperative planning. In respiratory medicine, this technology has been essentially used in central airway diseases to produce 3D airway models and to create airway splints and prostheses. In the last decade, it has led to a transformation and allowed progress in personalized medicine, making patient-specific stents for individuals with complex airway problems. A patient-specific stent using 3D printing may minimize complications, improve quality of life, and reduce the need for repeated procedures. This review describes the recent advances in 3D printing technology, its use for developing airway prostheses to treat complex airway diseases, and the current evidence that supports its use.

Role of systemic immunosuppression on subglottic stenosis in granulomatosis with polyangiitis: Analysis of a single-centre cohort

PURPOSE

Subglottic stenosis (SGS) is a potentially life-threatening manifestation of granulomatosis with polyangiitis (GPA). Endoscopic dilation is effective, but relapses are frequent and the benefit of systemic immunosuppression in this setting is still controversial. We aimed to investigate the role of immunosuppressive treatment on SGS relapse risk.

METHODS

This is a retrospective observational study based on review of medical charts among our cohort of patients with GPA.

RESULTS

Twenty-one patients with SGS-GPA were identified, with a prevalence of 20% among our entire GPA cohort (n = 105). Compared to patients without SGS, patients with SGS-GPA had an earlier disease onset (mean age 30.2 vs. 47.3 years, p<0.001), and lower BVAS (mean 10.5 vs 13.5; p = 0.018). Five patients didn't receive systemic immunosuppression for SGS and they all (100%) relapsed after the first procedure, while among medical treatment group relapse rate was 44% (p = 0.045). When single treatment regimens are considered, rituximab (RTX) and cyclophosphamide (CYC) yielded a protective role towards the need of subsequent dilation procedure after the first if compared with absence of medical treatment. Patients with SGS and generalized disease, who initially received either a RTX- or a CYC-based induction treatment, and higher cumulative doses of glucocorticoids, showed a delayed median time to SGS relapse (36 vs. 12 months, p = 0.024).

CONCLUSIONS

Subglottic stenosis is highly prevalent in patients with GPA and may define a milder systemic disease subset occurring more frequently in younger patients. Systemic immunosuppression provides benefit in preventing recurrence of SGS in GPA patients and regimens based on cyclophosphamide or rituximab might have a non-redundant role in this setting.

Flow-controlled ventilation and hi-flow nasal oxygen in laser surgery for a grade III subglottic stenosis patient

A 49-year old patient (BMI 29.4kg/m2 and ASA III) with grade III subglottic stenosis (> ventilator in flow controlled ventilation mode, which allowed us to regulate both inspiratory and expiratory flow without compromising gas exchange despite maintaining peak FIO2 at 0.3 due to the risk of ignition. Before proceeding with endoscopic dilation, the 4.5mm laser endotracheal tube was withdrawn and high flow nasal cannula oxygenation was started in order to prolong apnoeic oxygenation. Total apnoea time was 11min, maintaining SpO2>70%) underwent laser resection followed by dilation. During resection he was ventilated by the Evone>ventilator; high flow nasal cannula therapy; apnoeic oxygenation-98% and peak EtCO2 60mmHg throughout the procedure.

Ear, Nose, and Throat Manifestations of Vasculitis and Other Systemic Autoimmune Diseases: Otologic, Sinus, and Airway

Auricular, nasal, and laryngeal manifestations occur frequently in rheumatic diseases. Inflammatory ear, nose, and throat (ENT) processes often result in organ damage and have profound effects on quality of life. Herein, we review the otologic, nasal, and laryngeal involvement of rheumatic diseases, focusing on their clinical presentation and diagnosis. ENT manifestations generally respond to treatment of the systemic disease, which is outside the scope of this review; however, adjunctive topical and surgical treatment approaches, as well as treatment of idiopathic inflammatory ENT manifestations will be reviewed.

Subglottic Stenosis After Endonasal Resection of Juvenile Nasopharyngeal Angiofibroma

Subglottic stenosis (SGS), the narrowing of the upper trachea, can be an acquired condition in pediatric patients. Presenting with varying degrees of dyspnea and stridor, acquired SGS is most commonly due to intubation. Airway stenosis is often not considered a surgical complication, and no literature on acquired SGS after endoscopic sinus surgery exists. We present a unique case of a 13-year-old male with juvenile nasopharyngeal angiofibroma (JNA), who developed SGS in the setting of progressive dyspnea six weeks after endonasal resection of his mass. He required urgent intubation prior to preoperative embolization and endonasal surgery, which prolonged his total intubation period. After the patient was found to have acquired SGS, he eventually required serial dilation to treat his stenosis. The presentation and operative course of this patient, along with images and pathologic findings, are discussed. Based on an extensive literature review of PubMed, Medline, and Google Scholar, there have been no cases discussing SGS development post-intubation after endonasal surgery or in association with JNA. Acquired SGS can present as a life-threatening airway obstruction in pediatric patients. With the rise of endoscopic skull base surgery and the prevalence of JNA, this case study sheds light on the detection and management of SGS post-operatively.

The role of bronchoscopy in the multidisciplinary approach to benign tracheal stenosis

Benign tracheal stenosis can cause dyspnea, wheezing, and cough mimicking other obstructive lung diseases which often leads to a delay in the diagnosis. Risk factors and etiologies for tracheal strictures include autoimmune diseases, infection, gastro-esophageal reflux disease (GERD), radiation injury and iatrogenic factors such as post-intubation and post-tracheostomy. Once suspected, tracheal strictures are diagnosed by performing a thorough evaluation involving clinical exam, laboratory workup, pulmonary function test, chest imaging and bronchoscopy. Bronchoscopy plays a pivotal role in the diagnosis of stenosis and along with the imaging and physiologic assessments leads to a proper description of the stenosis based on all parameters that matters for management. Surgical resection provides a definitive management in most patients with idiopathic or post intubation/tracheostomy stenosis, however, factors such as severe co-morbidities, length and location of the stricture can preclude patients from undergoing curative surgery. Several bronchoscopic interventions including mechanical or laser assisted dilation, electrosurgery (ES), airway stenting and pharmacological treatment with mitomycin C (MMC) and intralesional steroid have been reported in the literature for management of patients who are not surgical candidates. Herein, we review the role of bronchoscopy and illustrate the importance of a multi-disciplinary team (MDT) approach comprising of interventional pulmonologists, thoracic surgeons and otorhinolaryngologists in the diagnosis and management of patients with benign tracheal stenosis.

Use of Mitomycin-C in Laryngotracheal Stenosis: A Focused Clinical Review

BACKGROUND

Therapeutic options for managing laryngotracheal stenosis (LTS) are limited. Endoscopy is a minimally invasive approach to treating LTS, but carries a high risk of stenosis recurrence. Mitomycin C (MMC) is often used as an adjunct therapy to delay the time to symptomatic recurrence of LTS. This review synthesizes the current literature on the topic of MMC as an adjunct treatment strategy for LTS.

METHODS

A focused literature search was carried out from PubMed on June 12, 2022 using the terms "mitomycin c AND stenosis" in all fields with no date limitations. Evidence-based recommendations relevant to the clinical application of MMC as an adjunct therapy for LTS were formulated. Three questions were addressed: 1) efficacy of MMC, 2) single versus multiple application(s) of MMC, and 3) safety of MMC. The evidence rating and recommendation strength were guided by the GRADE system.

RESULTS

Twenty-nine studies were reviewed. The efficacy of MMC as an adjunct therapy for LTS varied across studies. Randomized controlled trials have not shown an outcome difference with MMC use, although methodologic flaws including underpowering were noted. A meta-analysis of observational studies with a comparator arm found the unadjusted probability of remaining symptom-free for > 1 year is greater with versus without MMC application (73% vs. 35%). Single versus multiple application(s) of MMC resulted in similar restenosis rates at long-term follow-up. Complications related to MMC use are rarely reported using conventional doses (0.4 mg/mL). Overall, the quality of evidence was low and the recommendation for intervention was weak.

CONCLUSION

The role for MMC as an adjunct therapy in LTS is uncertain. While safe in its application, the efficacy of MMC in reducing stenosis recurrence remains a matter of debate. Large, prospective studies are needed to inform future recommendations.

The role of local expression of hormone receptors in the genesis of idiopathic tracheal stenosis

Background

Tracheal stenosis in adults is usually the result of mechanical injuries either from direct trauma, tracheotomy or intubation. Idiopathic stenosis in the cricotracheal section is a rare condition and occurs almost exclusively in females. Therefore, an influence of the female sexual hormones estrogen and progesterone has been assumed previously.

Methods

Tracheal specimens of 27 patients who received tracheal resection for either idiopathic tracheal stenosis (ITS) (n=11) or posttraumatic tracheal stenosis (PTTS) (n=16) between 2008 and 2019 in our surgical department were included and retrospectively analyzed. Immunohistochemical staining of tracheal specimens concerning the hormone receptor status of progesterone and estrogen was performed.

Results

While post-tracheotomy stenosis occurred in males (n=6) as well as in females (n=10), none of the patients with idiopathic stenosis were males. All of the idiopathic stenosis (n=11; 100%) showed a strong expression of the estrogen receptors (ERs) in the fibroblasts and expression of progesterone receptors (PRs) in fibroblasts in 8 of 11 (72.7%). In the post-tracheotomy patients, only 3/16 (18.8%) showed slight staining of PRs and 6/16 (37.5%) of ERs. Of those, only one male patient presented with expression of ERs and PRs and another male patient presented with isolated PRs. Oral intake of hormone compounds was seen in 11/27 (40.7%) patients: 7/11 (63.6%) in the ITS group and 4/16 (25%) in the PTTS (noteworthy that the PTTS group included 6 male patients).

Conclusions

Although the number of patients is small, our results show that the expression of female sexual hormone receptors in the fibroblasts of the trachea is a persistent finding in ITS. Surgery provided good results with a favorable long-term outcome without recurrence of stenosis for ITS and PTTS. Further investigation with a special focus on hormones is needed to assist in the prevention of this rare disease.

Impact of Socioeconomic Demographics and Race on Laryngotracheal Stenosis Etiology and Outcomes

OBJECTIVE

Certain sociodemographic variables are known to result in health care disparities. This study investigates potential differences in outcomes for patients with laryngotracheal stenosis (LTS) based on racial backgrounds and socioeconomic variables including insurance status and English language-Proficiency.

METHODS

Patients with LTS from 2016 to 2021were identified by relevant ICD codes. Variables including race, age, gender, language preference and insurance status were collected from medical records. Risk factors for LTS including COPD, smoking history, diabetes, GERD, and BMI were obtained. Etiology of LTS was categorized as autoimmune, traumatic, iatrogenic, or idiopathic. Need for temporary tracheostomy and tracheostomy dependence were determined at last follow-up visit.

RESULTS

129 patients were included for review. 70% of Black patients had iatrogenic LTS, whereas 65% of the White patient cohort had autoimmune or idiopathic LTS. Black patients were more strongly associated with temporary tracheostomy and tracheostomy dependence compared to White patients. Public health insurance and co-morbid GERD were associated with tracheostomy dependence for White patients only.

CONCLUSION

This study identified a disproportionate representation of Black patients in the iatrogenic etiology of LTS. Although controlling for risk factors of LTS, this cohort had an increased need for temporary tracheostomy and tracheostomy dependence compared to White and Latinx cohorts. This finding merits further study.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:908-913, 2023.

Proximal Scar Progression in Idiopathic Subglottic Stenosis After Wedge Excision: Does it Happen?

OBJECTIVE

To compare the incidence of glottic stenosis in idiopathic subglottic stenosis (iSGS) patients with no prior surgical intervention to those with a history of endoscopic dilation and characterize the incidence of glottic involvement, changes in scar length, and progression of scar toward glottis following laser wedge excision (LWE).

METHODS

A retrospective review of iSGS patients who underwent LWE between 2002 and 2021 was performed. Patients without prior airway surgery were labeled LWE primary (LWEP) and operative findings for LWEP patients were reviewed for glottic involvement, scar length (D_L ), and distance from the glottis to superior-most aspect of scar (D_GS ). Rates (in mm/procedure) of D_ΔL , reflecting an increase in length, and D_-ΔGS , reflecting proximal migration, were calculated by dividing D_ΔL and D_-ΔGS by the number of LWE procedures.

RESULTS

213 iSGS patients underwent LWE, with 132 being LWEP patients. LWEP had a lower incidence of baseline glottic involvement (n = 6, 4.5%) than LWE secondary (LWES; n = 6, 7.5%). Four new cases of glottic involvement were noted in LWEP patients following LWE, with only one being clinically significant resulting in permanently decreased vocal fold mobility. With each procedure, scar length increased by 1.0 mm and D_GS decreased by 0.7 mm, reflecting a migration or decrease in D_GS of 9.5% with each procedure with respect to initial D_GS . Overall rates of glottic stenosis following operations were similar between LWEP and LWES cohorts, 7.6% and 7.5% respectively.

CONCLUSION

There appears to be a low risk of glottic involvement resulting from the LWE procedure in iSGS patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:875-882, 2023.

Forbearance with endobronchial stenting: cognisance before conviction

Endobronchial stenting is an important aspect of the practice of interventional pulmonology. The most common indication for stenting is the management of clinically significant airway stenosis. The list of endobronchial stents available on the market continues to grow. More recently, patient-specific 3D-printed airway stents have been approved for use. Airway stenting should be considered only when all other options have been exhausted. Due to the environment of the airways and the stent-airway wall interactions, stent-related complications are common. Although stents can be placed in various clinical scenarios, they should only be placed in scenarios with proven clinical benefit. The unwarranted placement of a stent can expose the patient to complications with little or no clinical benefit. This article reviews and outlines the key principles of endobronchial stenting and important clinical scenarios in which stenting should be avoided.

Balloon dilatation is superior to CO2 laser excision in the treatment of subglottic stenosis

INTRODUCTION

Endoscopic treatment of subglottic stenosis (SGS) is regarded as a safe procedure with rare complications and less morbidity than open surgery yet related with a high risk of recurrence. The abundance of techniques and adjuvant therapies complicates a comparison of the different surgical approaches. The primary aim of this study was to investigate disease recurrence after CO₂ laser excisions and balloon dilatation in patients with SGS and to identify potential confounding factors.

MATERIALS AND METHODS

In a tertiary referral center, two cohorts of previously undiagnosed patients treated for SGS were retrospectively reviewed and followed for 3 years. The CO₂ laser cohort (CLC) was recruited between 2006 and 2011, and the balloon dilatation cohort (BDC) between 2014 and 2019. Kaplan‒Meier and multivariable Cox regression analyzed time to repeated surgery and estimated hazard ratios (HRs) for different variables.

RESULTS

Nineteen patients were included in the CLC, and 31 in the BDC. The 1-year cumulative recurrence risk was 63.2% for the CLC compared with 12.9% for the BDC (HR 33.0, 95% CI 6.57-166, p < 0.001), and the 3-year recurrence risk was 73.7% for the CLC compared with 51.6% for the BDC (HR 8.02, 95% CI 2.39-26.9, p < 0.001). Recurrence was independently associated with overweight (HR 3.45, 95% CI 1.16-10.19, p = 0.025), obesity (HR 7.11, 95% CI 2.19-23.04, p = 0.001), and younger age at diagnosis (HR 8.18, 95% CI 1.43-46.82, p = 0.018).

CONCLUSION

CO₂ laser treatment is associated with an elevated risk for recurrence of SGS compared with balloon dilatation. Other risk factors include overweight, obesity, and a younger age at diagnosis.

Can the Remote Use of a Peak Flow Meter Predict Severity of Subglottic Stenosis and Surgical Timing?

OBJECTIVE

We aimed to assess the relationship between patient-performed and patient-reported peak flow meter (PFM) measurements with pulmonary function testing (PFT) and Dyspnea Index (DI) scores as a tool for monitoring Subglottic stenosis (SGS) disease progression remotely.

METHODS

Thirty-five SGS patients were prospectively enrolled. Patients were given PFMs to report serial measurements from home. DI scores and PFT were recorded at serial clinic visits. Data were analyzed to determine the correlation between PFM measurements and PFT data. Pre-operative and post-operative PFM measurements, PFT, and DI scores were analyzed for patients who underwent operative intervention. Receiver operating characteristic (ROC) curves were created for PFM measurements, PFT data, and DI scores to predict the likelihood of surgery.

RESULTS

PFM measurements had a "strong" correlation with the peak expiratory flow rate (PEFR), r = 0.78. Means of PEFR, PIFR, EDI, PFM measurements, and DI scores all significantly improved after the operative intervention (p ≤ 0.05). The area under the curve for ROC curves for DI scores, PFM measurements, and EDI were highest in our cohort with values of 0.896, 0.823, and 0.806, respectively.

CONCLUSION

In our SGS cohort, PFM measurements correlate strongly with PEFR measurements. PFM measurements can adequately demonstrate disease progression and predict the need for surgery in this patient population. Together, DI scores and PFM measurements may be a useful tool to remotely follow patients with SGS and inform timing of in-person assessments.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:628-633, 2023.

Prevalence of anxiety during the COVID-19 pandemic in patients diagnosed with subglottic stenosis

OBJECTIVES

In the wake of the novel coronavirus disease (COVID-19), patients with subglottic stenosis (SGS) have a new, seemingly ubiquitous, respiratory disease to contend with. Whether real or perceived, it is likely that patients with SGS will feel exposed during the current pandemic. This study seeks to determine whether patients with SGS have increased rates of anxiety during the COVID-19 pandemic relative to healthy controls, as well as how much of an impact the pandemic itself plays in the mental health of this population.

METHODS

Retrospective review of 10 patients with a confirmed SGS diagnosis and 21 control patients were surveyed via telephone. Patients of all ages that had an in-person or virtual visit within 3 months of the survey start date were included.

RESULTS

A total of 30 patients were surveyed in this study, of whom 67.8 % were in the control group and 32.2 % were comprised of patients diagnosed with SGS. SGS patients reported a significantly higher level of anxiety on the GAD-7 scale with severe anxiety in 20 % of patients, moderate anxiety in 50 % of patients, mild anxiety in 20 %, and 10 % reporting no anxiety. Overall, the average reported GAD-7 score of the SGS patients and control patients were 10.8 ± 4.96 and 6.67 ± 2.96 respectively (p < 0.05).

CONCLUSIONS

This study is the first of its kind to analyze the rates and causes of anxiety within the context of the COVID-19 pandemic on patients diagnosed with subglottic stenosis. SGS patients were found to have a significantly higher anxiety based on the GAD-7 survey in comparison to patients without SGS.

LEVEL OF EVIDENCE

IV.

Hormone pathway comparison in non-idiopathic and idiopathic progressive subglottic stenosis

PURPOSE

Our previous study on the idiopathic progressive subglottic stenosis (IPSS) highlighted a possible hormonal mechanism, with over-expression of estrogen receptors alpha (ER-α) and progesterone receptors (PR). We tested whether such over-expression take place in non-idiopathic subglottic stenosis (NISS) as well.

METHODS

37 specimens of iatrogenic NISS were analyzed (20 females; mean age, 59 ± 12 years; range 41-85). Immunoreactivity of ER-α and PR was calculated as the product of intensity (1 = weak, 2 = moderate, 3 = strong) and positive cells percentage (1 to 4, for < 10%, 10-50%, 50-80%, and > 80%). This score was calculated on the stenotic tissue (ST), and stenosis margins (SM).

RESULTS

The expression of PR was significantly higher in ST of IPSS compared with female and male NISS patients (8.7 ± 3.1 vs. 4.9 ± 3.2, p < 0.001 for IPSS vs. female and 8.7 ± 3.1 vs. 2.1 ± 2.7, p < 0.01 for IPSS vs. male NISS patients). Contrarily, ER-α showed gender differences, as both IPSS and female NISS patients had similar, yet higher ER-α expression compared with male NISS patients (7.0 ± 4.2 vs. 6.5 ± 2.5, p = NS for IPSS vs. female and 7.0 ± 4.2 vs. 3.4 ± 2.0, p < 0.02 for IPSS vs. male NISS patients). There was no difference in fibroblast receptor expression between ST and SM. However, ER-α and PR expression was significantly lower in marginal mucous glands when compared with ST.

CONCLUSIONS

The IPSS pathogenesis appears to be driven by hormonal mechanisms, in particular, by over-expression of PR. Marginal cells display a reduced hormone receptor density. This finding could be interpreted as a compensatory mechanism. These findings could open up for targeted IPSS treatment.

Idiopathic double tracheal stenosis mimicking asthma: a case report

Idiopathic tracheal stenosis (Idio-SS) is an extremely rare disease. Its diagnosis is of exclusion and could be misdiagnosed as asthma. Herein, we report the case of a 39-year-old woman who had been treated for asthma for several months. She has no history of endotracheal intubation or granulomatous disease. Flexible fiberoptic bronchoscopy and thoracic computed tomography revealed double tracheal stenosis. The patient had rigid bronchoscopy; the upper tracheal stenosis was dilated with insertion of a silicone airway stent at the level of the distal stenosis. The diagnosis of idiopathic stenoses was made according to the clinico-radiological features. Symptoms were completely relieved and no recurrence was observed after one year of follow-up. This case highlights the importance of clinical suspicion and early diagnosis of Idio-SS in patients with unexplained wheezing and dyspnea. It also illustrates the role of endoscopic procedures in this situation.

Fatal Asphyxia Potentially Caused by COVID-19-Induced Exacerbation of Pre-existing Tracheal Stenosis

We report a case of cardiac arrest due to asphyxia caused by coronavirus disease 2019 (COVID-19) in a patient with no history of tracheal intubation but with a history of subglottic stenosis. A 54-year-old man suffered a cardiac arrest at home. The patient had tracheal stenosis; therefore, it was difficult to intubate. The patient had COVID-19, which was presumed to have aggravated the existing tracheal stenosis and caused asphyxiation. The patient died seven days later. This is, to our knowledge, the first report of a patient with subglottic stenosis potentially aggravated by COVID-19, resulting in asphyxia-related cardiopulmonary arrest. The patient could not be saved, but emergency physicians should be aware that airway obstruction can be caused by viral infections, including severe acute respiratory syndrome coronavirus 2 infections. Physicians should consider the difficulty in performing oral intubation and cricothyrotomy and be aware of alternative methods to secure the airway.

Short-term Endoscopic Outcomes of Balloon and Rigid Bronchoplasty in the Management of Benign Subglottic and Tracheal Stenosis

BACKGROUND

Endoscopic therapies are firmly established in the management algorithm of benign subglottic and tracheal stenosis (SGTS). The optimal dilation strategy, however, has yet to be elucidated. The objective of this study was to compare the efficacy and safety of balloon versus rigid bronchoplasty in the treatment of benign SGTS.

METHODS

De novo cases of benign SGTS at our institution over a 9-year period were retrospectively identified. Patients were divided into 2 groups based on the initial dilation strategy of balloon or rigid bronchoplasty. Demographics, clinical findings, concurrent interventions, lesion characteristics, and complications were analyzed. Two reviewers independently assigned an index and follow-up endoscopic stenosis grade for each case. The mean stenosis grade at follow-up in both groups was then calculated and compared.

RESULTS

Sixty-three patients with benign SGTS were included. Most stenoses in the rigid (80%) and balloon (63%) bronchoplasty groups were complex ( P =0.174). In addition, 94% (59/63) of index stenoses were classified as Cotton Myer Grade 3. At follow-up, no significant difference was found in the mean stenosis grade between dilation strategies (1.97 vs. 2.2, P =0.287). Furthermore, no procedural-related complications were observed in either group.

CONCLUSION

Balloon and rigid bronchoplasty are safe and effective endoscopic tools in the early management of benign SGTS. A multimodality approach centered around mucosal sparing techniques remains vitally important to the overall and likely long-term success of treating this challenging disease entity.

The efficiency of endoscopic versus open surgical interventions in adult benign laryngotracheal stenosis: a meta-analysis

BACKGROUND

The optimal treatments for adult benign laryngotracheal stenosis presently remains controversial. The majority of the disadvantages of endoscopic interventions with high recurrence rate and open surgical therapy accompanied by sophisticated techniques, complication and mortality, highlights the dilemma of option for treatments.

PURPOSE

To compare endoscopic treatments with open surgical interventions in adult patients with benign laryngotracheal stenosis, analyze their clinical outcomes, recurrence, complication and mortality.

METHODS

In the meta-analysis, the databases including PubMed, Embase, Ovid and Web of Science were searched for studies reporting adult benign laryngotracheal stenosis, and clinical outcomes were compared. The duplicate publications, reviews, comments or letters, conference abstracts, case reports were excluded. The random effect model was used for calculating the pooled effect estimates.

RESULTS

Eight studies (1627 cases) referring to six retrospective and two prospective researches were ultimately included in the meta-analysis. The decreased risk estimates of recurrence rate in patients receiving open surgical interventions were detected, comparing with endoscopic interventions (P < 0.05). Subgroup analysis revealed that decreased risk estimates of restenosis rate were also observed in patients receiving open surgical interventions compared with endoscopic interventions (P < 0.05), based on prospective studies, Europe and America, < 2-year follow-up, laryngeal stenosis, stenotic length without inter-group difference or stenotic grade II alone. However, there were no statistically significant difference of recurrence rate between the two interventions (P > 0.05) based on retrospective studies, South Asia and Africa, ≥ 2-year follow-up, involving tracheal lesion, stenotic length with inter-group difference, or stenotic grades of I-IV. No notable difference in the incidence of complication or mortality were identified.

CONCLUSIONS

Open surgical interventions were more suitable for most laryngotracheal stenosis without contraindications. Endoscopic interventions are increasingly being used to treat simple laryngotracheal stenosis, as well as complex airway stenosis in carefully selected cases. Multi-center prospective randomized controlled trials should be conducted to search for the standard treatments for laryngotracheal stenosis.

Diagnosing and treating ANCA-associated vasculitis: an updated review for clinical practice

ANCA-associated vasculitides (AAV) are a group of rare, primary, systemic necrotizing small-vessel vasculitides. Granulomatosis with polyangiitis and microscopic polyangiitis account for ∼80–90% of all AAV. Exposure to silica dust, farming and chronic nasal Staphylococcus aureus carriage are associated with increased risk of developing AAV. When a diagnosis of AAV is suspected, as in patients with multisystem organ dysfunction or those with features such as chronic recurrent rhinosinusitis, cavitated lung nodules, palpable purpura or acute kidney injury, then appropriate further investigations are needed, including ANCA testing. In this scenario, a structured clinical assessment should be conducted, evaluating all the organs possibly involved, and tissue biopsy may be necessary for confirmation of the diagnosis. Therapeutic algorithms vary based on the severity of AAV, the clinical diagnosis/ANCA specificity, and the patient’s age, weight, comorbidities and prognosis. Recent data favour rituximab as a preferable option for both induction and maintenance of remission. In addition, regimens with less glucocorticoids are equally effective and safer in inducing remission compared with conventional regimens, and avacopan is an effective glucocorticoid-sparing option. In contrast, there is not compelling evidence to support the routine use of plasma exchange in addition to standard remission-induction therapy in AAV. ANCA and other biomarkers can be helpful in association with clinical assessment to guide diagnosis and treatment decisions. Patients should be frequently evaluated during follow-up for possible disease relapses or treatment-related morbidity, and for monitoring damage accrual, especially metabolic and cardiovascular damage.

Subglottic stenosis masquerading as asthma in a young adult: an overlooked and delayed diagnosis

An otherwise fit young woman presented with a 10-year history of non-progressive wheeze and 'noisy breathing'. She had previously been diagnosed with teenage-onset asthma but had been unresponsive to inhaled corticosteroids and bronchodilators. A dysfunctional breathing disorder had been considered a possible diagnosis by several general practitioners, and there were no features to suggest systemic conditions. The patient had undergone an otherwise apparently uncomplicated intubation general anaesthetic for a gastroenterological investigation 13 years earlier. An outpatient flexible endoscopic examination of the upper aerodigestive tract demonstrated an isolated subglottic stenosis which was characterised by cross-sectional imaging. Microlaryngoscopy confirmed a smooth subglottic stenosis which was dilated using a minimally invasive balloon dilatation technique to good clinical effect.

Complications following laser wedge excision for idiopathic subglottic stenosis

OBJECTIVES

Endoscopic laser wedge excision (LWE) is an effective treatment option for idiopathic subglottic stenosis (iSGS); however, data regarding complications following LWE are limited. The aim of the following analysis was to provide a review of frequency and type of complications that occur with LWE in patients with iSGS.

STUDY DESIGN

Retrospective review.

METHODS

Patients with iSGS undergoing LWE between January 2002 and September 2021 were performed. Demographic data were recorded. Complications were stratified into major and minor categories. The frequency of these complications and the respective treatment for them was analyzed.

RESULTS

212 patients within the study period underwent a total of 573 LWE procedures. All but two patients were female, with a median age of 54 years at time of LWE. Of these patients, 43 (20 %) patients experienced a complication. Of these, only 7 (15 %) of the reported complications were considered major while the rest were minor in nature. Major complications included 3 cases of post-operative hemoptysis, 1 case of tracheitis, and 3 cases of reduced vocal fold hypomobility with concurrent glottic stenosis. Minor complications consisted of 2 cases of tooth fracture and 34 cases of tongue paresthesia post-operatively that was self-limited. There were no mortalities.

CONCLUSION

Major complications occur in <5 % of LWE procedures based off the analysis. All major complications were managed without significant long-term morbidity. Minor complications with the LWE are self-limited in nature. Our data supports the LWE as a safe treatment option for iSGS.

LEVEL OF EVIDENCE: 4

The critical period for development of secondary restenosis following post-intubation tracheal stenosis surgery

BACKGROUND

Determining a predictable duration to restenosis very essential for reducing mortality and morbidity for tracheal stenosis surgery.

OBJECTIVES

The aim of this study was to determine the critical periods for secondary restenosis risk for operated patients with post-intubation tracheal stenosis (PITS) during the initial healing period.

METHODS

A total of 61 patients with a diagnosis of surgically treated PITS were included in the study. Treatment groups were carbon dioxide (CO₂) laser and tracheal resection with primary anastomosis (TRPA). Duration to restenosis was compared with Kaplan-Meier curves between study groups.

RESULTS

Restenosis developed in 11 (18.0%) patients and was diagnosed after a mean of 39.3 ± 38.5 (range, 22 to 155) days. Gender or Cotton-Myer grade of the PITS was not found to be risk factors for the development of stenosis. Restenosis rate was 33.3% in CO₂ laser group and 10% in the TRPA group (p = .036). Duration to restenosis was detected at a median of 28 days in patients treated with CO₂ laser, and a median of 30 days in patients treated with TRPA (p = .024).

CONCLUSIONS

The most critical period for the development of restenosis after PITS treatment is the third and fourth weeks, especially in patients treated with CO₂ laser.