The Role of Systemic Steroids in Postintubation Tracheal Stenosis: A Randomized Clinical Trial

Post-Tracheostomy Steroid Nebulization: A Retrospective Analysis on Postoperative Complications

The primary objective of this research was to meticulously evaluate the therapeutic potential of steroid nebulization, administered over a 2-week period post-tracheostomy, in attenuating postoperative complications with a concentrated emphasis on tracheal stenosis. The study spanned three years, commencing in 2019 and concluding in 2022, examining a patient cohort of 400 individuals. Utilizing a retrospective cohort methodology, the participants were systematically stratified into two cohorts: those subjected to steroid nebulization (n = 200) and a control group (n = 200). Adverse outcomes were bifurcated into minor complications, which encompass stomal infections and inflammations, and major complications, which include bleeding, tracheoesophageal fistula, and tracheal stenosis. These complications were evaluated at distinct post-operative junctures: 1 week, 1 month, 3 months, and 6 months. The primary outcome was deduced through a rigorous multivariate logistic regression model, incorporating variables such as age, sex, and the diagnosis of chronic obstructive pulmonary disease (COPD). Analytical data unveiled that the cohort administered with steroid nebulization manifested a statistically significant diminution in the incidence of complications when juxtaposed with the control group (25 vs. 38%). Predominantly, the incidence of tracheal stenosis was discernibly lower in the steroid nebulization group (10 vs. 22%). The multivariate analytical framework further corroborated the pivotal role of steroid nebulization in substantially reducing the propensity for tracheal stenosis. The therapeutic intervention of steroid nebulization in the aftermath of a tracheostomy procedure presents a commendable avenue in curtailing major complications, with an acute focus on tracheal stenosis. To fortify these preliminary findings, it is quintessential to undertake more exhaustive studies, such as randomized controlled trials, to ascertain the optimal regimen concerning nebulization's timing, dosage, and duration.

Recombinant Slit2 attenuates tracheal fibroblast activation in benign central airway obstruction by inhibiting the TGF-β1/Smad3 signaling pathway

Airway fibrosis is among the pathological manifestations of benign central airway obstruction noted in the absence of effective treatments and requires new drug targets to be developed. Slit guidance ligand 2-roundabout guidance receptor 1 (Slit2-Robo1) is involved in fibrosis and organ development. However, its significance in airway fibrosis has not yet been reported. The study explored how the recombinant protein Slit2 functions in transforming growth factor-β1 (TGF-β1)-mediated airway fibrosis in vivo and in vitro. In this study, Slit2 expression initially increased in the tracheal granulation tissues of patients with tracheobronchial stenosis but decreased in the fibrotic tissue. In primary rat tracheal fibroblasts (RTFs), recombinant Slit2 inhibited the expression of extracellular matrices such as Timp1, α-SMA, and COL1A2, whereas recombinant TGF-β1 promoted the expression of Robo1, α-SMA, and COL1A2. Slit2 and TGF-β1 played a mutual inhibitory role in RTFs. Slit2 supplementation and Robo1 downregulation inhibited excessive extracellular matrix (ECM) deposition induced by TGF-β1 in RTFs via the TGF-β1/Smad3 pathway. Ultimately, exogenous Slit2 and Robo1 knockdown-mediated attenuation of airway fibrosis were validated in a trauma-induced rat airway obstruction model. These findings demonstrate that recombinant Slit2 alleviated pathologic tracheobronchial healing by attenuating excessive ECM deposition. Slit2-Robo1 is an attractive target for further exploring the mechanisms and treatment of benign central airway obstruction.

Challenges and successful management of subglottic tracheal stenosis in a 2‑year‑old child: A case report and a mini‑review of the literature

Tracheal stenosis is a narrowing of the windpipe that can lead to shortness of breath, stridor and even suffocation. The present study reports the clinical course of a patient with this condition in an aim to help clinicians obtain more information about this rare condition and identify potential treatment options. A 2-year-old female child presented with progressive shortness of breath and stridor. She was initially managed with tracheostomy; however, this was unsuccessful in relieving the stenosis. Subsequent interventions, including rigid bronchoscopy and dilatation were successful in relieving the condition. A benign hypertrophy of the bronchial wall was identified through biopsy. The patient was treated with steroids and antibiotics, and she experienced a marked improvement in symptoms and remained asymptomatic after a 1-year follow-up. Tracheal stenosis is a rare, yet serious condition that may be life-threatening. Thus, the early diagnosis and treatment of this condition are essential in order to improve outcomes.

[Management of Tracheobronchial Stenoses]

Tracheobronchial stenoses consist of a spectrum of conditions that may result in focal or diffuse narrowing of the trachea or downstream bronchial system. The purpose of this paper is to provide an overview of the most commonly encountered conditions in terms of diagnosis and therapeutic options as well as the associated challenges for practitioners.

Risk factors for developing subglottic and tracheal stenosis from the medical intensive care unit

Objective

Endotracheal intubation is a common procedure in the medical intensive care unit (MICU), but it carries risk of complications including, but not limited to, subglottic stenosis (SGS) and tracheal stenosis (TS). Current literature suggests identifiable risk factors for the development of airway complications. This study is a comprehensive evaluation of potential risk factors in patients who developed SGS and TS following endotracheal intubation in our MICU.

Methods

Patients intubated in our MICU were identified from 2013 to 2019. Diagnoses of SGS or TS within 1 year of MICU admission were identified. Data extracted included age, sex, body measurements, comorbidities, bronchoscopies, endotracheal tube size, tracheostomy, social history, and medications. Patients with prior diagnosis of airway complication, tracheostomy, or head and neck cancer were excluded. Univariate and multivariate logistic regressions were performed.

Results

A total of 136 patients with TS or SGS were identified out of a sample of 6603 patients intubated in the MICU. Cases were matched to controls who did not develop airway stenosis based on identical Charlson Comorbidity Index scores. Eighty six controls were identified with a complete record of endotracheal/tracheostomy tube size, airway procedures, sociodemographic data, and medical diagnosis. Regression analysis showed that SGS or TS were associated with tracheostomy, bronchoscopy, chronic obstructive pulmonary disease, current tobacco use, gastroesophageal reflux disease, systemic lupus erythematosus, pneumonia, bronchitis, and numerous medication classes.

Conclusion

Various conditions, procedures, and medications are associated with an increased risk of developing SGS or TS.

Level of evidence

4.

Systemic Steroids for Otolaryngology-Head and Neck Surgery Disorders: An Evidence-Based Primer for Clinicians

OBJECTIVE

To offer pragmatic, evidence-informed guidance on the use of systemic corticosteroids (SCS) for common otolaryngologic disorders.

DATA SOURCES

PubMed, Cochrane Library, and American Academy of Otolaryngology-Head and Neck Surgery Foundation clinical practice guidelines.

REVIEW METHODS

A comprehensive search of published literature through November 2021 was conducted on the efficacy of SCS, alone or in combination with other treatments, for managing disorders in otolaryngology and the subdisciplines. Clinical practice guidelines, systematic reviews, and randomized controlled trials, when available, were preferentially retrieved. Interventions and outcomes of SCS use were compiled to generate summary tables and narrative synthesis of findings.

CONCLUSIONS

Evidence on the effectiveness of SCS varies widely across otolaryngology disorders. High-level evidence supports SCS use for Bell's palsy, sinonasal polyposis, and lower airway disease. Conversely, evidence is weak or absent for upper respiratory tract infection, eustachian tube dysfunction, benign paroxysmal positional vertigo, adenotonsillar hypertrophy, or nonallergic rhinitis. Evidence is indeterminate for acute laryngitis, acute pharyngitis, acute sinusitis, angioedema, chronic rhinosinusitis without polyps, Ménière's disease, postviral olfactory loss, postoperative nerve paresis/paralysis, facial pain, and sudden sensorineural hearing loss.

IMPLICATIONS FOR PRACTICE

Clinicians should bring an evidence-informed lens to SCS prescribing to best counsel patients regarding the risks, anticipated benefits, and limited data on long-term effects. Alternate routes of corticosteroid administration-such as sprays, drops, inhalers, and intralesional injections-may be preferable for many disorders, particularly those that are self-limited or require a prolonged duration of therapy. Prudent use of SCS reduces the risk of medication-related adverse effects. Clinicians who are conversant with high-level evidence can achieve optimal outcomes and stewardship when prescribing SCS.

Therapeutic and prophylactic effects of radiation therapy in the management of recurrent granulation tissue induced tracheal stenosis: a review on the role of Endobronchial brachytherapy and external beam radiation therapy

PURPOSE

Granulation tissue-induced tracheal stenosis (mainly secondary to intubation or lung transplantation) is one of the most common etiologies of benign airway obstructions. Recurrence rates after standard treatment options (surgical resection and/or endobronchial interventions) can inadvertently worsen the stricture through the stimulation of more granulation tissue generation (via increased fibroblast activity and roliferation). Low-dose radiotherapy could be a promising tool to prevent granulation tissue formation after surgery and/or endobronchial interventions regarding its established role in the treatment of keloids or hypertrophic scars, two benign diseases with similar a pathophysiology to tracheal stenosis. This study reviews case reports and small series that used endobronchial brachytherapy (EBBT) or external beam radiotherapy (EBRT) for the management of refractory granulation tissue-induced tracheal stenosis after surgery and/or endobronchial interventions.

METHODS AND MATERIALS

Case reports and series (published up to October 2022) that reported outcomes of patients with recurrent granulation tissue-induced tracheal stenosis (after surgery and/or endobronchial interventions) treated by EBBT or EBRT (in definitive or prophylactic settings) were eligible.

RESULTS

Sixteen studies (EBBT: nine studies including 69 patients, EBRT: seven studies including 32 patients) were reviewed. The pooled success rate across all studies was 74% and 97% for EBBT and EBRT, respectively.

CONCLUSIONS

Radiation therapy appears to be effective in the management of selected patients with recurrent/refractory tracheal stenosis. Response to this treatment is usually good, but further studies with a larger number of patients and long-term followup are necessary to determine the optimal technique, dose, and timing of radiation therapy, late complications, the durability of response, and criteria for patient selection.

Photomodulative effects of low-level laser therapy on tracheal fenestration developed in in vivo model

The effect of low-level laser therapy (LLLT) on variable mucosal lesions in the upper aerodigestive tract has been reported. However, the effect of LLLT on tracheostomy sites or tracheal fenestration is rarely reported. In this study, we evaluate the effect of LLLT performed using 635 nm laser light based on a cylindrical diffuser and an animal model with tracheal fenestration. An animal model of tracheal fenestration is developed by suturing the trachea to the skin after performing a vertical tracheostomy from the second to the fifth tracheal ring of Wistar rats (male, body weight 200-250 g). LLLT (spot size: 2 cm²) is conducted once daily for five days using a handheld cylindrical device. Twenty-four rats are randomly assigned to a no-therapy or LLLT group with an energy density of 20 J/cm². Histological analysis is performed at 7 and 14 days after tracheal fenestration. Irradiation at the tracheal fenestration site with an energy density of 20 J/cm² improves the wound healing, as shown at 2 weeks after tracheostomy. Histological analysis shows significantly decreased acute inflammation and granulation tissue, as well as better cartilage regeneration and less tracheal wall thickening. Therefore, LLLT demonstrates therapeutic potential for preventing tracheal stenosis and granuloma after tracheostomy.

GDF15 alleviates the progression of benign tracheobronchial stenosis by inhibiting epithelial-mesenchymal transition and inactivating fibroblasts

Benign tracheobronchial stenosis (BTS) is a fatal and incurable disease. Epithelial repair and matrix reconstruction play an important role in the wound repair process. If the interstitial context is not restored and stabilized in time, it can lead to pathological fibrosis. Here we attempted to identify cytokines that are involved in promoting wound repair. Growth differentiation factor 15 (GDF15) is a cytokine secreted by tracheal epithelial cells, which is indispensable for the growth of epithelial cells and inhibits the overgrowth of fibroblasts. GDF15 can counteract transforming growth factor-β (TGFβ1) stimulation of epithelial-mesenchymal transition (EMT) in tracheal epithelial cells and inhibit fibroblast activation via the TGFβ1-SMAD2/3 pathway. In a rat model of tracheal stenosis, GDF15 supplementation alleviated the degree of tracheal stenosis. These results suggest that GDF15 prevents fibroblast hyperactivation and promotes epithelial repair in injured trachea. GDF15 may be a potential therapy to improve benign tracheobronchial stenosis.

Treatment of scarring central airway stenosis with pirfenidone: Case report

INTRODUCTION

Benign scarring central airway stenosis can be managed by high-pressure balloon dilatation, laser, surgery and stent implantation. The stenosis may have a high recurrence rate that necessitates repeated treatment. Pirfenidone (PFD) has anti-fibrosis effects and has been used in a variety of fibrosis diseases. Animal experiments suggested that PFD can prevent tracheal stenosis.

PATIENT CONCERNS

Patients with scarring central airway stenosis usually have chest tightness, cough and dyspnea.

DIAGNOSIS

Computed tomography scanning showed stenosis of the trachea and/or bronchus. Bronchoscopy revealed occlusion or stenosis of the trachea or bronchus.

INTERVENTIONS

The use of PFD in combination with other interventional management was reported to treat 2 cases of tracheobronchial stenosis after injury in this study. In the combined use of PFD and interventional management, PFD could help to alleviate tracheobronchial stenosis, prolong the time interval of bronchoscopic interventional treatment, and reduce medical costs.

OUTCOMES

The stenosis in the trachea and/or bronchus is relieved and the patients do not have any relevant symptoms.

Construction and Comprehensive Analysis of the ceRNA Network to Reveal Key Genes for Benign Tracheal Stenosis

Objective: To explore the possible biological functions of the differentially expressed genes in patients with benign tracheal stenosis, and to provide a valuable molecular basis for investigating the pathogenesis of benign tracheal stenosis.

Method: Whole transcriptome sequencing was performed on blood samples collected from patients with benign tracheal stenosis and normal controls. Differentially expressed mRNA, lncRNA, and circRNA were analyzed using the DESeq2 package. The protein interaction networks for differentially expressed mRNAs were constructed by STRING. The results of gene co-expression network analysis, Starbase database prediction, and differential gene expression were combined to construct a competing endogenous RNA network. The transcription factors of key genes were predicted using the Network Analyst database and a transcription factor-mRNA regulatory network was constructed. The classical pathways, intermolecular interaction networks, and upstream regulatory components of key genes were analyzed using Ingenuity Pathway Analysis (IPA). Finally, the DGIDB database was used to predict the potential therapeutic drugs to target the identified key genes.

Result: Based on mRNA, lncRNA and circRNA expression data, we found that differentially expressed mRNAs were enriched in oxygen transport, neutrophil activation, immune response, and oxygen binding. Then the pearson correlation between mRNAs of 46 key genes and lncRNAs and cricRNAs were calculated, and the correlation greater than 0.9 were selected to construct the co-expression network of “mRNA-lncRA” and “mRNA-cricRNA.” Moreover, a “lncRNA-miRNA-mRNA” network and a “circRNA-miRNA-mRNA” network were constructed. IPA analysis showed that the 46 key genes were significantly associated with inflammatory activation and acute respiratory distress syndrome. The constructed TF-mRNA regulatory network was composed of 274 nodes and 573 interacting pairs. 251 potential therapeutic drugs were identified from the DGIDB database.

Conclusion: This study analyzed the differential genes associated with benign tracheal stenosis and explored the potential regulatory mechanisms, providing a scientific reference for further studies on the pathogenesis of benign tracheal stenosis.

Patterned Drug-Eluting Coatings for Tracheal Stents Based on PLA, PLGA, and PCL for the Granulation Formation Reduction: In Vivo Studies

Expandable metallic stent placement is often the only way to treat airway obstructions. Such treatment with an uncoated stent causes granulation proliferation and subsequent restenosis, resulting in the procedure’s adverse complications. Systemic administration of steroids drugs in high dosages slows down granulation tissue overgrowth but leads to long-term side effects. Drug-eluting coatings have been used widely in cardiology for many years to suppress local granulation and reduce the organism’s systemic load. Still, so far, there are no available analogs for the trachea. Here, we demonstrate that PLA-, PCL- and PLGA-based films with arrays of microchambers to accommodate therapeutic substances can be used as a drug-eluting coating through securely fixing on the surface of an expandable nitinol stent. PCL and PLA were most resistant to mechanical damage associated with packing in delivery devices and making it possible to keep high-molecular-weight cargo. Low-molecular-weight methylprednisolone sodium succinate is poorly retained in PCL- and PLGA-based microchambers after immersion in deionized water (only 9.5% and 15.7% are left, respectively). In comparison, PLA-based microchambers retain 96.3% after the same procedure. In vivo studies on rabbits have shown that effective granulation tissue suppression is achieved when PLA and PLGA are used for coatings. PLGA-based microchamber coating almost completely degrades in 10 days in the trachea, while PLA-based microchamber films partially preserve their structure. The PCL-based film coating is most stable over time, which probably causes blocking the outflow of fluid from the tracheal mucosa and the aggravation of the inflammatory process against the background of low drug concentration. Combination and variability of polymers in the fabrication of films with microchambers to retain therapeutic compounds are suggested as a novel type of drug-eluting coating.

Plumbagin attenuates traumatic tracheal stenosis in rats and inhibits lung fibroblast proliferation and differentiation via TGF-β1/Smad and Akt/mTOR pathways

Traumatic tracheal stenosis (TS) is a serious respiratory disease characterized by hyperplasia of airway granulation. Plumbagin (PLB) is a natural naphthoquinone component with anti-fibrotic properties. This research aimed to explore the roles of PLB in alleviating TS and the underlying mechanisms. For in vitro studies, lung fibroblasts (IMR-90 cells), with/without PLB treatment or TGF-β1 induction, were used. The viability and proliferation of IMR-90 cells were examined by CCK-8 and EdU incorporation assays. The differentiation of IMR-90 cells was assessed by detecting the mRNA and protein expression levels of collagen (COL)-1 and alpha-smooth muscle actin (α-SMA). Besides, immunofluorescence assay was conducted to evaluate the localization of α-SMA in TGF-β1-induced IMR-90 cells. Moreover, the combination of PLB with/without TβRI (SB-431,542), PI3K/Akt (Ly294002) or mTOR (rapamycin) inhibitor was pretreated on IMR-90 cells after TGF-β1 induction. For in vivo studies, a rat model of TS was established. The pathological features and severity of TS were determined by hematoxylin and eosin staining. The protein levels of TGF-β1/Smad and Akt/mTOR pathways were detected for both in vitro and in vivo models. PLB effectively inhibited the proliferation and differentiation of TGF-β1-induced IMR-90 cells, and suppressed TGF-β1/Smad and Akt/mTOR signaling pathways both in vivo and in vitro. Furthermore, PLB reduced the degree of TS in rats. Taken together, our results indicate that PLB regulates lung fibroblast activity and attenuates TS in rats by inhibiting TGF-β1/Smad and Akt/mTOR signaling pathways. In conclusion, this study implies that PLB may serve as a promising therapeutic compound for TS.

Antifibrotic Role of Nintedanib in Tracheal Stenosis After a Tracheal Wound

OBJECTIVES/HYPOTHESIS

Tracheal stenosis is an obstructive disease of the upper airway that commonly develops as a result of abnormal wound healing. We evaluated the anti-inflammatory and antifibrotic properties of nintedanib on tracheal stenosis both in vitro and in vivo.

STUDY DESIGN

Prospective controlled animal study and in vitro comparative study of human cells.

METHODS

An animal model of tracheal stenosis was induced via tracheal trauma. Postsurgical rats were orally administered with nintedanib (10 or 20 mg/kg/d) or saline (negative control) for 2 weeks, and tracheal specimens were harvested after 3 weeks. Degree of stenosis, collagen deposition, fibrotic surrogate markers expression, and T-lymphocytic infiltration were evaluated. Human fetal lung fibroblast-1 (HFL-1) cells were cultured to determine the effects of nintedanib on changes of cellular biological function induced by transforming growth factor-β1 (TGF-β1).

RESULTS

Rat tracheal stenotic tissues exhibited thickened lamina propria with irregular epithelium, characterized by significantly increased collagen deposition and elevated TGF-β1, collagen I, α-SMA and fibronectin expressions. Nintedanib markedly attenuated the tracheal stenotic lesions, reduced the collagen deposition and the expression of fibrotic marker proteins, and mitigated CD4+ T-lymphocyte infiltration. Additionally, cellular proliferation and migration were decreased dose-dependently in TGF-β1-stimulated HFL-1 cells when treated with nintedanib. Furthermore, nintedanib inhibited TGF-β1-induced HFL-1 differentiation and reduced the mRNA levels of the profibrotic genes. TGF-β1-activated phosphorylation of the TGF-β/Smad2/3 and ERK1/2 pathways were also blocked by nintedanib.

CONCLUSION

Nintedanib effectively prevented tracheal stenosis in rats by inhibiting fibrosis and inflammation. The antifibrotic effect of nintedanib may be achieved by inhibiting fibroblasts' proliferation, migration and differentiation and suppressing the TGF-β1/Smad2/3 and ERK1/2 signaling pathways.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E2496-E2505, 2021.

Postintubation Multisegmental Tracheal Stenosis: A 24-Year Experience

BACKGROUND

Management of multisegmental tracheal stenosis is challenging. In this 24-year longitudinal single-center study, we present an algorithmic treatment approach.

METHODS

A retrospective analysis of 2167 patients with postintubation tracheal stenosis indicated 83 (3.83%) patients with multisegmental tracheal stenosis. Patients were assigned to 4 management groups according to the length, location, and severity of stenoses; tracheal infection/mucositis; laryngeal function; symptoms; general condition; and comorbid diseases. Type 1 (n = 13): 1-stage resection of both strictures, Type 2 (n = 6): 2-stage resection of both strictures, Type 3 (n = 40): resection of 1 stricture and nonresectional management of the other, Type 4 (n = 24): nonresectional management of both strictures. Outcomes were categorized as Good, Acceptable, or Poor. Univariate analyses for factors predictive of recurrence and outcome were performed.

RESULTS

Follow-ups were completed in 70 (84.34%) patients (median, 22.5 months). Outcome was assessed as Good in 56 (82.35%), Acceptable in 10 (14.71%), Poor in 2 (2.94%), and mortality in 2 (2.94%) patients. The median length of airway resection was 46, 67.5, and 40 mm in Types 1-3, respectively. Only 11 (13.25%) patients had no history of tracheostomy or tracheal surgery. By univariate analysis, a shorter intubation period was associated with Good outcome (P = .017). No factors predictive of recurrence or outcome were ascertained.

CONCLUSIONS

Multisegmental tracheal stenosis, generally caused by performing an inappropriate tracheostomy, is an iatrogenic disease that can be prevented. Although resection of both strictures may be feasible and is associated with Good results, in the majority of cases, a combination of surgical resection and non-resectional methods are sufficient to achieve Good results.

Successes and Failures in Tracheal Bioengineering: Lessons Learned

BACKGROUND

Controversy in tracheal reconstruction using grafts and bioengineered constructs highlights the importance of animal studies before human application. Small animal models help to refine designs but do not adequately model sizes relevant to human anatomy. We have conducted extensive large animal studies and summarize our findings in 26 consecutive transplants.

METHODS

We pooled 26 large animal studies together to investigate common elements related to successes and failures. In general the engineered tracheal graft consisted of a decellularized extracellular matrix surgical patch supported by a 3-dimensional-printed plastic polymer scaffold. Circumferential graft coverage ranged from 50% to 100%, spanning the length of 4 to 6 tracheal rings. Some grafts included embedded stem cells. Control grafts were fabricated without the support scaffold. At death grafts were harvested and examined grossly and through histology.

RESULTS

The support scaffold prevented graft malacia and collapse. Luminal epithelialization was most extensive in grafts with smaller circumferential coverage. Smaller circumferential coverage was also associated with longest animal survival. Chondrogenesis was only observed in grafts with embedded stem cells. Survival time was shortest in 100% circumferential grafts. Granulation tissue was an issue for all graft designs.

CONCLUSIONS

Large animal models capture challenges and complexities relevant to human anatomy. Development of granulation tissue remains a challenge, especially in circumferential grafts. Significant additional research is needed to investigate granulation tissue formation and to provide actionable insight into its management.

Hybrid Knife, a Novel Drug Delivery Tool for Treatment of Tracheal Stenosis: A Case Report

The treatment of subglottic stenosis remains a challenge due to anatomic and technological limitations, and there is no consensus regarding treatment. Restenosis and granulation formation are the most common complications. Balloon dilatation combined with cryotherapy and adjuvant topical medication is one treatment method. However, the efficacy of adjuvant topical medication is controversial, and the lack of efficacy may be related to the effective dose of the drug delivered to the submucosal layer of the lesion. Therefore, a tool with high efficiency for delivering medications to the submucosal layer via injection may play an important role in treatment. A hybrid knife (HK) with a pressure water jet traditionally used in endoscopy submucosal dissection to inject saline into the submucosa was employed here to inject medications for subglottic stenosis, followed by electrical excision. Here, we report the case of a man with complex subglottic stenosis who underwent balloon dilatation combined with cryotherapy and an adjuvant submucosal triamcinolone injection performed with an HK. The drug was delivered more efficiently into the submucosal layer, and the lumen of the trachea was patent. Performing a submucosal injection with an HK may be a new approach to deliver medications to the submucosal layer for the treatment of tracheal stenosis.

A Randomized Controlled Trial of Dexamethasone as a Prophylactic Treatment for Subglottic Stenosis in a Rabbit Model

OBJECTIVE

Iatrogenic injury is a common cause of subglottic stenosis (SGS). We investigated the role of pre-injury dexamethasone as a preventive treatment for iatrogenic subglottic stenosis.

METHODS

16 New Zealand White rabbits were used in an IACUC approved study. Subjects were divided into two groups: intramuscular dexamethasone (DEX) at a dose of 2 mg/kg 15 minutes prior to an endoscopic injury to create SGS, and the same injury creation with a preoperative intramuscular saline (SAL) injection. Three independent, blinded raters evaluated endoscopic images to obtain cross sectional area (CSA) airway measurements. Rabbit airways were measured just prior to injury and at one week post-injury. All subjects were provided as-needed postoperative steroids and buprenorphine for symptoms of respiratory distress. Data analysis was performed using Student t-test. Intraclass correlation coefficients were used to assess inter-rater agreement.

RESULTS

All subjects survived to the one-week post-injury airway evaluation. There was no difference in airway size between groups prior to injury (P = .28). Subjects in the DEX group demonstrated an average stenosis of 20.3% (95% CI 10.2-30.5) at one week compared to 60.6% (95% CI 40.3-80.9) in the SAL group (P = .01). Subjects in the control group required significantly more doses of postoperative dexamethasone (P = .02). Inter-rater agreement for between raters was excellent (ICC = .88).

CONCLUSION

This is the first study to examine the role of pre-injury glucocorticoids in preventing iatrogenic subglottic stenosis. In our model, a single dose of intramuscular dexamethasone given prior to a subglottic injury resulted in a statistically significant reduction in airway stenosis. This research suggests that administering systemic dexamethasone should be considered prior to any procedure that may injure the subglottis, including traumatic intubation, to prevent iatrogenic subglottic stenosis.

Bioinformatics analysis and verification of gene targets for benign tracheal stenosis

Background

Tracheal injury could cause intratracheal scar hyperplasia which in turn causes benign tracheal stenosis (TS). With the increasing use of mechanical ventilation and ventilator, the incidence of TS is increasing. However, the molecular mechanisms of TS have not been elucidated. It is significant to further explore the molecular mechanisms of TS.

Methods

The repeatability of public data was verified. Differently expressed genes (DEGs) and most significant genes were identified between TS and normal samples. Enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were analyzed. The comparative toxicogenomics database were analyzed. TS patients were recruited and RT‐qPCR were performed to verify the most significant genes.

Results

There exist strong correlations among samples of TS and normal group. There was a total of 194 DEGs, including 61 downregulated DEGs and 133 upregulated DEGs. GO were significantly enriched in mitotic nuclear division, cell cycle, and cell division. Analysis of KEGG indicated that the top pathways were cell cycle, and p53 pathway. MKI67(OMIM:176741), CCNB1(OMIM:123836), and CCNB2(OMIM:602755) were identified as the most significant genes of TS, and validated by the clinical samples.

Conclusion

Bioinformatics methods might be useful method to explore the mechanisms of TS. In addition, MKI67, CCNB1, and CCNB2 might be the most significant genes of TS.

Airway Management Following Tracheal Surgery

The ability to remove longer segments of airway and to extend resections into the larynx proper has managed to create novel situations that will require attention to postoperative management. This article deals with prophylactic measures to prevent the requirement of assisted ventilation. It, however, also emphasizes various bronchoscopic and intubation techniques, which if required, will help to avoid trauma to the airway anastomosis. In addition, a variety of ventilator modalities are discussed that were developed by the author over many years at the Toronto General Hospital.