Pediatric Airway Balloon Dilation: Urge for Safety Redesign.

Airway balloons are widely used by otolaryngologists to treat laryngotracheal stenosis. We review an adverse event and interventions that may prevent similar occurrences. There are no other reports of similar incidents in the Food and Drug Administration Manufacturer and User Facility Device Experience. We implore Acclarent to redesign their airway balloon device to prevent accidental airway irrigation.

Early chemotherapeutic intervention to avoid thyroidectomy in pediatric Langerhans cell histiocytosis with thyroid involvement accompanying tracheal stenosis: a report of two cases.

Thyroid involvement is rare in pediatric Langerhans cell histiocytosis (LCH). It may cause airway narrowing, leading to acute-onset respiratory distress. Severe cases may require emergent surgical interventions such as thyroidectomy, which should be avoided in children due to higher rates of complication, particularly in infancy. There is currently no consensus on the indications for surgical treatment in LCH with thyroid involvement. In this report, we describe the cases of two children who presented with tracheal stenosis caused by thyroid LCH, both of which were successfully treated by early induction of chemotherapy, and one of which was also treated for a shorter duration. Mutation analysis detected in-frame deletions of BRAF exon 12 in both cases. These cases suggest that timely diagnosis and administration of chemotherapy may alleviate severe airway obstruction and reduce the need for thyroidectomy in pediatric patients with thyroid LCH.

One-lung Ventilation for Patients With Laryngo-tracheal Stenosis: A Case Report and Literature Review.

Context: Laryngo-tracheal stenosis (LTS) is a relatively rare disease, and conventional methods have difficulty achieving one-lung ventilation (OLV) when an anatomical abnormality exists. Selecting an appropriate method for patients with LTS can ensure oxygenation, collapse the lung, and reduce damage. Objective: The study intended to perform a comprehensive review of the literature and a systematic review to examine the characteristics and management of OLV for LTS patients. Design: The research team performed a narrative review by searching the PubMed and China National Knowledge Infrastructure (CNKI) databases. The search used the keywords one-lung ventilation and tracheal stenosis. The team then performed a review, including the studies found in the search and the research team's own case study. Setting: The study took place at the First Hospital of Jilin University in Changchun, Jilin, China. Participant: The participant in the current case study was a 72-year-old, female patient with generalized tracheal narrowing. Results: Nine participants achieved OLV through BB, with the anesthesiologist performing SLT and using extraluminal BB for six participants. Conclusions: Several methods can successfully achieve OLV for patients with difficult airways, but the current research team found that a small, single-lumen tube (SLT) and extraluminal bronchial blocker (BB) may be a better choice for patients with tracheal stenosis.

Autologous Airway Basal Cell Transplantation Alleviates Airway Epithelium Defect in Recurrent Benign Tracheal Stenosis.

BACKGROUND: Airway epithelium defects are a hallmark of recurrent benign tracheal stenosis (RBTS). Reconstructing an intact airway epithelium is of great importance in airway homeostasis and epithelial wound healing and has great potential for treating tracheal stenosis. METHODS: An experimental study was conducted in canines to explore the therapeutic effect of autologous basal cell transplantation in restoring airway homeostasis. First, airway mucosae from human patients with recurrent tracheal stenosis were analyzed by single-cell RNA sequencing. Canines were then randomly divided into tracheal stenosis, Stent, Stent + Cells, and Stent + Cells + Biogel groups. Autologous airway basal cells of canines in the Stent + Cells and Stent + Cells + Biogel groups were transplanted onto the stenotic airway after modeling. A biogel was coated on the airway prior to basal cell transplantation in the Stent + Cells + Biogel group. After bronchoscopic treatments, canines were followed up for 16 weeks. RESULTS: Single-cell RNA sequencing demonstrated packed airway basal cells and an absence of normal airway epithelial cells in patients with RBTS. Autologous airway basal cell transplantation, together with biogel coating, was successfully performed in the canine model. Follow-up observation indicated that survival time in the Stent + Cells + Biogel group was significantly prolonged, with a higher (100%) survival rate compared with the other groups. In terms of pathological and bronchoscopic findings, canines that received autologous basal cell transplantation showed a reduction in granulation hyperplasia as well as airway re-epithelialization with functionally mature epithelial cells. CONCLUSIONS: Autologous airway basal cell transplantation might serve as a novel regenerative therapy for airway re-epithelialization and inhibit recurrent granulation hyperplasia in benign tracheal stenosis.

Chronic respiratory disorders due to aberrant innominate artery: a case series and critical review of the literature.

BACKGROUND: Tracheal compression (TC) due to vascular anomalies is an uncommon, but potentially serious cause of chronic respiratory disease in childhood. Vascular slings are congenital malformations resulting from abnormal development of the great vessels; in this group of disorders the most prevalent entity is the aberrant innominate artery (AIA). Here we provide a report on diagnosis and treatment of AIA in nine children with unexplained chronic respiratory symptoms. We describe the cases, perform a literature review, and provide a discussion on the diagnostic workup and treatment that can help manage AIA. METHODS: Clinical history, diagnostic procedures and treatment before and after the AIA diagnosis were retrospectively reviewed in nine children (5 boys and 4 girls), who were referred for recurrent-to-chronic respiratory manifestations over 10 years (2012-2022). We performed a comprehensive report on the ongoing clinical course and treatment as well as an electronic literature search on the topic. RESULTS: Diagnoses at referral, before AIA was identified, were chronic dry barking cough associated with recurrent pneumonia (n = 8, 89%), lobar/segmental atelectasis (n = 3, 33%), atopic/non atopic asthma (n = 3, 33%); pneumomediastinum with subcutaneous emphysema complicated the clinical course in one case. When referred to our Unit, all patients had been previously treated with repeated antibiotic courses (n = 9, 100%), alone (n = 6, 67%) or combined with prolonged antiasthma medications (n = 3, 33%) and/or daily chest physiotherapy (n = 2, 22%), but reported only partial clinical benefit. Median ages at symptom onset and at AIA diagnosis were 1.5 [0.08-13] and 6 [4-14] years, respectively, with a relevant delay in the definitive diagnosis (4.5 years). Tracheal stenosis at computed tomography (CT) was ≥ 51% in 4/9 cases and ≤ 50% in the remaining 5 subjects. Airway endoscopy was performed in 4 cases with CT evidence of tracheal stenosis ≥ 51% and confirmed CT findings. In these 4 cases, the decision of surgery was made based on endoscopy and CT findings combined with persistence of clinical symptoms despite medical treatment. The remaining 5 children were managed conservatively. CONCLUSIONS: TC caused by AIA may be responsible for unexplained chronic respiratory disease in childhood. Early diagnosis of AIA can decrease the use of expensive investigations or unsuccessful treatments, reduce disease morbidity, and accelerate the path toward a proper treatment.

[Efficacy of high-frequency electrotome combined with balloon dilatation and cryotherapy through electronic bronchoscope in the management of lumen occlusion type of tracheobronchial tuberculosis].

The lumen-occlusion type of tracheobronchial tuberculosis is the most severe type of tracheobronchial stenosis of tuberculosis, often leading to atelectasis or even lung damage in patients. Some patients require surgical resection of the diseased airways and lungs, which can seriously affect their quality of life and even be life-threatening. In order to improve the treatment ability of bronchoscopy physicians for lumen occlusion type of tracheobronchial tuberculosis, this article retrospectively analyzed 30 cases of tracheobronchial tuberculosis with lumen occlusion in Hunan Chest Hospital, and summarized the experience of achieving better results by high-frequency electrotome combined with balloon dilatation and cryotherapy.

Two cases with postintubation tracheal stenosis after COVID-19 pneumonia.

Only a small percent of all intubated SARS-CoV-2-positive patients survive because of the development of severe respiratory and multiorgan failure. The development of tracheal stenosis after orotracheal intubation or tracheostomy is a dangerous complication with gross consequences for the patient and medical staff. Endoscopic interventional procedures could be used in simple tracheal stenosis and surgical resection and anastomosis are reserved for complex stenosis or after unsuccessful endoscopic treatment. We present two cases with tracheal stenosis as a complication of prolonged intubation in COVID-19 survivors which was diagnosed up to 6 months after discharge. Clinical management and surgical techniques are also discussed.

Heliox simulations for initial management of congenital laryngotracheal stenosis.

OBJECTIVES: Congenital laryngotracheal stenosis is rare, potentially severe, and difficult to manage. Heliox is a medical gas effective in obstructive airway pathologies, given its physical properties. This study aims to model the interest of Heliox in reducing the respiratory work in congenital laryngotracheal stenosis, using numerical fluid flow simulations, before considering its clinical use. DESIGN: This is a retrospective study, performing Computational Fluid Dynamics numerical simulations of the resistances to airflow and three types of Heliox, on 3D reconstructions from CT scans of children presenting with laryngotracheal stenosis. PATIENTS: Infants and children who were managed in the Pediatric ENT department of a tertiary-care center and underwent CT scanning for laryngotracheal stenosis between 2008 and 2018 were included. RESULTS: Fourteen models of congenital laryngotracheal stenosis were performed in children aged from 16 days to 5 years, and one model of the normal trachea in a 5-year-old child. Tightest stenosis obtained the highest airway resistances, ranging from 40 to 10 kPa/L/s (up to 800 times higher than in the normal case). Heliox enabled a decrease in pressure drops and airway resistances in all stenosis cases, correlated to increasing Helium concentration. CONCLUSIONS: Heliox appears to reduce pressure drops and airway resistances in 3D models of laryngotracheal stenosis. It may represent a supportive treatment for laryngotracheal stenosis, while waiting for specialized care, thanks to the reduction of respiratory work.

Investigation on forced vibration characteristics of Nitinol tracheal stent.

BACKGROUND: Tracheal stents can be placed in a narrow position in the human trachea to ensure smooth breathing. And the stent will deform during service by the influence of the physiological environment or random excitations, such as coughing. METHODS: This paper divides the vibration into periodic and random vibrations according to the different pressures. And a coupling vibration model was established by analyzing the contact relationship between the stent and the trachea tissue. And this study discusses the influence of tracheal diameter, respiratory pressure, and frequency on the stent vibration characteristics through Ansys simulation. In addition, the nonlinear equations were solved by the Matlab numerical analysis method, which could help analyze the influence of cough intensity on the stability of the tracheal stent system. RESULTS: The results showed that when tracheal stenosis occurred in the trachea's more significant grade, the trachea stent was more likely to fall off when treated with a tracheal stent. With the increase in respiratory frequency and pressure, the deformation of the tracheal stent is more considerable. Moreover, the frequency of normal cough hardly affects the stability of the stent system, while the excitation force and damping coefficient value greatly influence the system. When the excitation force of the cough exceeds the critical importance of 20 N, the tracheal stent is prone to fall off. This study comprehensively obtained the forced vibration characteristics of the stent under service conditions, which could make up for the shortage of the vibration theory of the stent. CONCLUSION: The results can provide a theoretical basis for predicting the possibility of stent loss in clinical treatment.

[Relationship between etiology and morphological classification of benign central airway stenosis and its prognosis].

Objectives: To analyze the relationship between etiology and morphological classification of benign central airway stenosis and its prognosis. Methods: We performed a retrospective study of the medical records of 453 patients initially diagnosed with benign airway stenosis at Department of Respiratory Diseases in Beijing Tiantan Hospital affiliated to Capital Medical University from January 2003 to October 2019. Of 453 patients, 260 were male. The age of the study population was 12-86(44.0±24.5) years. Results: Among the 453 patients diagnosed with benign central airway stenosis, 161 case (35.5%, including 113 post-tracheostomy tracheal stenosis and 48 post-intubation tracheal stenosis) were iatrogenic; 88 cases were from benign tumors (19.4%), 77 cases from tracheal or bronchial tuberculosis (17.0%), 71 case from tracheal foreign bodies (15.7%). Disease causes varied among different gender or age groups. The main type of stenosis was structural stenosis, of which 241 cases (53.2%) were intra-luminal and 183 cases (40.4%) were scar contracture type. The site of stenosis showed a certain relationship with the causes of stenosis. The stenosis degree was mainly from grade 2 to grade 4 (76.4%), and the length was mainly within 3 cm (84.8%). Single factor analysis on the relationship between disease cause, morphological classification and prognosis of benign central airway stenosis showed statistically better prognosis in groups that were caused by benign tumor, intraductal stenosis or stenosis that were 3-4 in degree and 1-2 degree in length. Conclusion: The common causes of central airway stenosis included iatrogenic stenosis, benign tumor, tracheal or bronchial tuberculosis and tracheal foreign bodies. Benign airway stenosis with different disease causes and morphological classification had different prognosis after bronchoscopic interventional treatment. Clinicians should know the disease causes, morphological characterization and risk factors for benign airway stenosis for earlier diagnosis, treatment or prevention.

A narrative review of new research progress regarding the use of airway stents in benign airway stenosis.

INTRODUCTION: Benign airway stenosis is a severe disease that can result in death with improper treatment. Clinicians must know about airway stents to choose the best one in their daily practice. AREAS COVERED: PubMed, Embase, and other electronic databases and websites were searched to identify relevant randomized controlled trials and meta-analyses. This review summarizes different types of airway stents and analyzes their advantages and disadvantages. EXPERT OPINION: Increasing attention has been given to the indications and prognosis of benign airway stenosis treated with different airway stents. With more investigations and data, better alternatives to silicone stents could be developed in the future.

Impact of pregnancy on airway complications after intubation for COVID-19 infection: A case series.

Coronavirus disease (COVID-19) is associated with severe acute respiratory illness, often requiring intensive care unit admission. Some patients require prolonged intubation and mechanical ventilation. Post-intubation laryngotracheal stenosis occurs in approximately four to 13 % of adult patients after prolonged intubation in the absence of COVID-19 infection. The rate of COVID-19 related post-intubation laryngotracheal stenosis may be higher. Of 339 pregnant patients with COVID-19, we identified seven who required intubation and mechanical ventilation. Four of the seven developed persistent airway complications, and laryngotracheal stenosis, the most severe, was present in three. Each patient had variations in duration of intubation, endotracheal tube size, re-intubation, presence of superimposed infections, and pre-existing comorbidities. We speculate that underlying physiologic changes of pregnancy in addition to the increased inflammatory state caused by COVID-19 are associated with an increased risk of post-intubation laryngotracheal stenosis. Otolaryngology physicians should have a low threshold for considering this pathophysiology when consulting on obstetric patients who have previously been intubated with COVID-19. Otolaryngologists can educate obstetricians when caring for pregnant patients who have laryngotracheal stenosis, especially those who may require emergency airway management for obstetric indications.

Establishment of two canine models of benign airway stenosis and the effect of mitomycin C on airway stenosis.

OBJECTIVES: Cuffed endotracheal intubation and stent implantation were employed to simulate two types of benign airway stenosis and further to analysis the different features between them from trachecscopic characteristics, gross anatomy to histopathological changes. In addition, our study explored the therapeutic effect of mitomycin C at different concentrations on granulation tissue caused by stent implantation in order to provide a new therapeutic strategy for clinical treatment of benign airway stenosis. METHODS: Twelve beagle dogs were randomly divided into four groups, with three dogs in each group. Group A: Three beagle dogs were intubated through oral trachea after general anesthesia and cuff pressure maintained at 200 mmHg for 24 h. Group B, Group C and Group D: endotracheal coated self-expanding metal stents were placed after general anesthesia under the guidance of bronchoscope. On the Day7 after stent implantation, Group B, as control group, was injected phosphate buffer solution of 1 ml into granulation tissue at the end of stent; Group C was injected mitomycin C of 1 ml at 0.4 mg/ml and Group D was injected mitomycin C of 1 ml at 0.8 mg/ml into granulation tissue at the end of metal airway stent respectively, the same method as Group B. Bronchoscopy was used to observe tracheal lumen on the seventh day, fourteenth day and twenty-first day after modeling and pathological changes were examined on twenty-first day. RESULTS: Two models of benign airway stenosis can be established by cuffed endotracheal intubation and stent implantation. There was tracheal rupture in the trachea cartiage ring in the cuffed endotracheal intubation group, but was't in stent implantation group. Histopathological characteristics were different between cuffed endotracheal intubation and stent implantation groups. In stent placement groups, we found that the stenosis degree of mitomycin C at 0.4 mg/ml was approximately 19%-32%, mitomycin C at 0.8 mg/ml was approximately 16%-21% and the control group was approximately 36%-47%. CONCLUSION: The two models of canine benign tracheal stenosis induced by cuffed endotracheal intubation and stent implantation are relatively simple, reliable and reproducible and have different characteristics. Mitomycin C could inhibit proliferation of granulation tissue and attenuate the degree of airway stenosis caused by stent implantation.

Laryngotracheal stenosis: Mechanistic review.

BACKGROUND: The purpose of this review article is to summarize the existing literature surrounding wound healing mechanisms in laryngotracheal stenosis. METHODS: A review of general wound healing pathophysiology, followed by a focused review of iatrogenic laryngotracheal stenosis (iLTS) and idiopathic subglottic stenosis (iSGS) as conditions of aberrant wound healing. RESULTS: iLTS is the scarring of the laryngotracheal complex, coming secondary to injury from prolonged intubation. iSGS is a chronic fibroinflammatory scarring and narrowing of the subglottic airway in the absence of any obvious preceding injury or trauma. They are both thought to result from a prolonged and dysregulated wound healing response that promotes the deposition of pathologic scar in the airway. CONCLUSIONS: Understanding the mechanisms that underlie wound healing will help identify and intervene on the process early in its development and discover future therapies that target individual wound healing mechanisms limiting the incidence of this recalcitrant disease process.

Tracheal Stenosis After Prolonged Intubation Due to COVID-19.

OBJECTIVES: The authors aimed to evaluate the characteristics and management outcomes of patients who developed tracheal stenosis after invasive mechanical ventilation (IMV) due to COVID-19. DESIGN, SETTING, AND PARTICIPANTS: The data of 7 patients with tracheal stenosis and 201 patients without tracheal stenosis after IMV due to COVID-19 between March 2020 and October 2021 were retrospectively analyzed. INTERVENTIONS: Flexible bronchoscopy was performed for the diagnosis of tracheal stenosis and the evaluation of the treatment's effectiveness, and rigid bronchoscopy was applied for the dilatation of tracheal stenosis. MEASUREMENTS AND MAIN RESULTS: In the follow-up period, tracheal stenosis was observed in 7 of 208 patients (2 women, 5 men; 3.3%). The patients were divided into 2 groups as patients with tracheal stenosis (n = 7) and patients without tracheal stenosis (n = 201). There were no statistically significant differences between the 2 groups in terms of age, sex, body mass index, and comorbidities (p > 0.05). The mean duration of IMV of the patients with tracheal stenosis was longer than patients without tracheal stenosis (27.9 ± 13 v 11.2 ± 9 days, p < 0.0001, respectively). Three (43%) of the stenoses were web-like and 4 (57%) of them were complex-type stenosis. The mean length of the stenoses was 1.81 ± 0.82 cm. Three of the patients were treated successfully with bronchoscopic dilatation, and 4 of them were treated with tracheal resection. CONCLUSIONS: Tracheal stenosis developed in 7 of 208 (3.3%) patients with COVID-19 who were treated with IMV. The most important characteristic of patients with tracheal stenosis was prolonged IMV support.

Noninvasive positive pressure ventilation in the assessment of extrinsic tracheal stenosis.

In patients with extrinsic tracheal stenosis caused by a mediastinal mass, an airway stent is a palliative measure to relieve airway obstruction. However, the self-expanding force of the stent may be insufficient to force a rigid stenosis. Our goal was to report a simple strategy to indirectly estimate the rigidity of the stenosis and predict airway patency after inserting the stent. Before the procedure, the inspiratory and expiratory flows and their ratio were evaluated under spontaneous breathing and after positive pressure ventilation generated by a facial mask. In patients with stenosis successfully treated with a stent (n = 11), we found significant changes in expiratory (2.3 ± 0.7 vs 2.8 ± 0.7; p = 0.03) and inspiratory (1.5 ± 0.6 vs 2.5 ± 0.9; p = 0.001) flows and a reduction of their ratio (1.4 ± 0.3 vs 1.1 ± 0.2; p = 0.01) whereas no significant changes were observed in patients (n = 2) whose stent failed to force the stenosis. In these cases, a tracheostomy was performed to assure ventilation. Our simple strategy may help physicians predict airway patency after stenting or plan alternative treatments in patients with rigid stenosis difficult to force by stenting.

Tracheal stenosis following mild-to-moderate COVID-19 infection without history of tracheal intubation: a case report.

Laryngotracheal stenosis is a major side effect of intubation in patients with Coronavirus 2019 (COVID-19). However, no study has since reported tracheal stenosis in patients with COVID-19 without a history of tracheal intubation. The current study reports a 77-year-old male patient with the COVID-19 infection but without a history of tracheal intubation diagnosed with distal tracheal stenosis. Tracheal stenosis was successfully treated with rigid bronchoscopy. This study reported the first case of tracheal stenosis due to viral tracheitis associated with COVID-19 infection. However, further studies are required to investigate this speculation.

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.

Presentation, Diagnosis, and Management of Subglottic and Tracheal Stenosis During Systemic Inflammatory Diseases.

BACKGROUND: Subglottic stenosis (SGS) and tracheal stenosis (TS) are characterized by a narrowing of the airways. The goal of this study was to describe the characteristics and prognosis of nontraumatic and nontumoral SGS or TS. RESEARCH QUESTION: What are the inflammatory etiologies of SGS and TS, and what are their characteristics and prognosis? STUDY DESIGN AND METHODS: This multicenter, observational retrospective study was performed in patients with SGS or TS that was neither traumatic nor tumoral. RESULTS: Eighty-one patients were included, 33 (41%) with granulomatosis with polyangiitis (GPA) and 21 (26%) with relapsing polychondritis (RP). GPA-related stenoses exhibited circumferential subglottic narrowing in 85% of cases, without calcifications. In contrast, RP-related stenoses displayed anterior involvement in 76%, in a longer distance from vocal cords (4 cm), with calcifications in 62%, and extension to bronchi in 86%. Other diagnoses included bullous dermatoses (n = 3), amyloidosis (n = 3), sarcoidosis (n = 2), and Crohn's disease (n = 2); the remaining stenoses (n = 15) were idiopathic. SGS/TS was the initial manifestation of the disease in 66% of cases, with a median interval from stenosis to disease diagnosis of 12 months (interquartile range, 0-48 months). Despite the use of glucocorticoids in 80%, combined with methotrexate in 49%, endoscopic procedures were required in 68% of patients. Relapses of stenoses occurred in 76% without any difference between causes (82% in GPA, 67% in RP, and 75% in idiopathic SGS/TS). Three patients died due to the stenosis, two of RP and one of GPA. INTERPRETATION: These data show that GPA and RP are the two main inflammatory diseases presenting with SGS/TS. GPA-related stenoses are mostly subglottic and circumferential, whereas RP-related stenoses are mostly tracheal, anterior, and calcified with a frequent extension to bronchi. Relapses of stenoses are common, and relapse rates do not differ between causes. Diagnosis and management of SGS/TS require a multidisciplinary approach.