Impact of fundoplication for gastroesophageal reflux in the outcome of benign tracheal stenosis

Bio-Inspired Magnetically Responsive Silicone Cilia: Fabrication Strategy and Interaction with Biological Mucus

Cilia are biological structures essential to drive the mobility of secretions and maintain the proper function of the respiratory airways. However, this motile self-cleaning process is significantly compromised in the presence of silicone tracheal prosthesis, leading to biofilm growth and impeding effective treatment. To address this challenge and enhance the performance of these devices, we propose the fabrication of magnetic silicone cilia, with the prospect of their integration onto silicone prostheses. The present study presents a fabrication method based on magnetic self-assembly and assesses the interaction behavior of the cilia array with biological mucus. This protocol allows for the customization of cilia dimensions across a wide range of aspect ratios (from 6 to 85) and array densities (from 10 to 80 cilia/mm2) by adjusting the fabrication parameters, offering flexibility for adjustments according to their required characteristics. Furthermore, we evaluated the suitability of different cilia arrays for biomedical applications by analyzing their interaction with bullfrog mucus, simulating the airways environment. Our findings demonstrate that the fabricated cilia are mechanically resistant to the viscous fluid and still exhibit controlled movement under the influence of an external moving magnet. A correlation between cilia dimensions and mucus wettability profile suggests a potential role in facilitating mucus depuration, paving the way for further advancements aimed at enhancing the performance of silicone prostheses in clinical settings.

Brazilian airway surgery survey indicates low overall numbers and need for improved teaching skills

OBJECTIVES

The Brazilian Society of Thoracic Surgeons conducted an online survey to determine the number of surgeons that perform adult and paediatric airway surgery and to understand the practice patterns along the country.

METHODS

Active members were electronically invited to complete the questionnaire through the REDCapR platform. Invitations were sent from January to April 2020. The survey encompassed 40 questions that explored 4 different topics in the assessment of tracheal diseases: (i) surgeon's demography; (ii) institutional profile, (iii) education and training in laryngo-tracheal surgery and (iv) preoperative and postoperative evaluation.

RESULTS

Eighty-nine percentage of the responders declared to perform tracheal surgery with a median of 5 tracheal resection procedures per year [interquartile range (IQR) 3-12]. Interaction with other specialties occurs in 37.3% of cases. Access to technology and devices is highly variable across the country. Resident training in airway surgery consists in traditional lectures in 97% of the cases. Training in animals (15.2%), cadavers (12.1%) and simulators (6.1%) are rare. Preoperatory evaluation encompasses flexible bronchoscopy (97.8%) and/or computed tomography (CT) scan of the airways (90.6%). Swallowing (20.1%) and voice (14.4%) disorders are rarely evaluated. Eighty-nine percentage of the surgeons consider bronchoscopy to be the preoperatory gold-standard exam, followed by CT scan (38.8%) and CT-3D reconstruction (37.4%).

CONCLUSIONS

Brazilian surgeons refer that airway resection and reconstruction are part of their current practice, but the total number of procedures per surgeon per year is low. Access to high-end technology and equipment is heterogenous. Training offered to residents in most academic institutions relies on traditional lectures.

Inhaled fosamprenavir for laryngopharyngeal reflux: Toxicology and fluid dynamics modeling

Objectives

Approximately 25% of Americans suffer from laryngopharyngeal reflux (LPR), a disease for which no effective medical therapy exists. Pepsin is a predominant source of damage during LPR and a key therapeutic target. Fosamprenavir (FOS) inhibits pepsin and prevents damage in an LPR mouse model. Inhaled FOS protects at a lower dose than oral; however, the safety of inhaled FOS is unknown and there are no inhalers for laryngopharyngeal delivery. A pre-Good Lab Practice (GLP) study of inhaled FOS was performed to assess safety and computational fluid dynamics (CFD) modeling used to predict the optimal particle size for a laryngopharyngeal dry powder inhaler (DPI).

Methods

Aerosolized FOS, amprenavir (APR), or air (control) were provided 5 days/week for 4 weeks (n = 6) in an LPR mouse model. Organs (nasal cavity, larynx, esophagus, trachea, lung, liver, heart, and kidney) were assessed by a pathologist and bronchoalveolar lavage cytokines and plasma cardiotoxicity markers were assessed by Luminex assay. CFD simulations were conducted in a model of a healthy 49-year-old female.

Results

No significant increase was observed in histologic lesions, cytokines, or cardiotoxicity markers in FOS or APR groups relative to the control. CFD predicted that laryngopharyngeal deposition was maximized with aerodynamic diameters of 8.1-11.5 μm for inhalation rates of 30-60 L/min.

Conclusions

A 4-week pre-GLP study supports the safety of inhaled FOS. A formal GLP assessment is underway to support a phase I clinical trial of an FOS DPI for LPR.

Level of Evidence

NA.

Analysis of clinical characteristics of 617 patients with benign airway stenosis

Introduction

Benign airway stenosis (BAS), namely airway narrowing caused by a variety of benign lesions, can lead to varying degrees of breathing difficulties and even death due to asphyxia. This study aimed to elucidate the clinical characteristics of BAS, including etiology, treatment and pathology, by analyzing the clinical data of BAS patients.

Methods

A retrospective analysis was conducted using the clinical data of 617 BAS cases from January 2017 to December 2022. The pathological characteristics of the tissues were assessed by hematoxylin-eosin (H&E) and Masson's staining. Besides, protein expression levels were determined by immunohistochemistry (IHC).

Results

A total of 617 patients were included (333 females [53.97%] and 284 males [46.03%]), with an average age of 48.93 ± 18.30 (range 14-87). Tuberculosis (n = 306, 49.59%) and trauma (n = 179, 29.02%) were the two leading etiologies of BAS, followed by airway foreign bodies (FB, n = 74, 11.99%), external compression (n = 25, 4.05%) and other etiologies (n = 33, 5.35%). Among 306 tuberculous tracheobronchial stenosis (TBTS) cases, most were females (n = 215, 70.26%), and TBTS mainly occurred in the left main bronchus (n = 97, 31.70%), followed by the right middle bronchus (n = 70 cases, 22.88%). The majority of TBTS patients (n = 259, 84.64%) were treated by interventional therapy. The condition of 179 BAS patients was ascribed to trauma, such as tracheal intubation (n = 92, 51.40%), tracheotomy (n = 69, 38.56%), injury (n = 15, 8.38%) and surgery (n = 3, 1.68%), which mostly took place in the trachea (n = 173, 96.65%). TAS patients mainly received interventional therapy (n = 168, 93.85%) and stent implantation (n = 47, 26.26%). The granulation tissues of BAS primarily featured inflammation, proliferation and fibrosis. IHC indicated the up-regulated expressions of transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), collagen type I protein (COL-I) and vimentin, and the down-regulated expression of E-cadherin, which indicated fibrosis and epithelial-mesenchymal transition (EMT).

Conclusion

Tuberculosis was the main etiology, and trauma was the secondary etiology. The granulation tissues of BAS were characterized by inflammation, fibrosis and probably EMT. Comprehensive interventional therapy is an effective method of treating BAS.

Oral and Inhaled Fosamprenavir Reverses Pepsin-Induced Damage in a Laryngopharyngeal Reflux Mouse Model

OBJECTIVE

More than 20% of the US population suffers from laryngopharyngeal reflux. Although dietary/lifestyle modifications and alginates provide benefit to some, there is no gold standard medical therapy. Increasing evidence suggests that pepsin is partly, if not wholly, responsible for damage and inflammation caused by laryngopharyngeal reflux. A treatment specifically targeting pepsin would be amenable to local, inhaled delivery, and could prove effective for endoscopic signs and symptoms associated with nonacid reflux. The aim herein was to identify small molecule inhibitors of pepsin and test their efficacy to prevent pepsin-mediated laryngeal damage in vivo.

METHODS

Drug and pepsin binding and inhibition were screened by high-throughput assays and crystallography. A mouse model of laryngopharyngeal reflux (mechanical laryngeal injury once weekly for 2 weeks and pH 7 solvent/pepsin instillation 3 days/week for 4 weeks) was provided inhibitor by gavage or aerosol (fosamprenavir or darunavir; 5 days/week for 4 weeks; n = 3). Larynges were collected for histopathologic analysis.

RESULTS

HIV protease inhibitors amprenavir, ritonavir, saquinavir, and darunavir bound and inhibited pepsin with IC50 in the low micromolar range. Gavage and aerosol fosamprenavir prevented pepsin-mediated laryngeal damage (i.e., reactive epithelia, increased intraepithelial inflammatory cells, and cell apoptosis). Darunavir gavage elicited mild reactivity and no discernable protection; aerosol protected against apoptosis.

CONCLUSIONS

Fosamprenavir and darunavir, FDA-approved therapies for HIV/AIDS, bind and inhibit pepsin, abrogating pepsin-mediated laryngeal damage in a laryngopharyngeal reflux mouse model. These drugs target a foreign virus, making them ideal to repurpose. Reformulation for local inhaled delivery could further improve outcomes and limit side effects.

LEVEL OF EVIDENCE

NA. Laryngoscope, 133:S1-S11, 2023.

Tracheobronchial Surgery in Emerging Countries

Tracheobronchial surgery is widely performed in emerging countries mainly as a consequence of the high number of airway-related complications and poor management in intensive care units. This has led to great expertise in the surgical management of postintubation tracheal stenosis, and opportunity for advancing scientific knowledge. Nonetheless, tracheal stenosis has a severe impact on a patient's quality of life, is a major burden to the health system, and should be prevented. Incorporation of innovative techniques, technologies, and prospective databases should prompt earlier diagnosis and lead to fewer complications.

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.

Hybrid Desobstruction of Blind-end Subglottic Stenosis With Long-term Stenting

Blind-end stenosis (Myer-Cotton IV) is an extreme response to airway injury, resulting in phonatory ablation and dependence on a tracheostomy. A minimally invasive airway desobstruction and stenting can be beneficial in such cases. We present 2 cases of Myer-Cotton IV stenosis that were treated with a minimally invasive desobstruction using a hybrid (endoscopic-surgical) approach followed by the placement of a silicone T-tube.

Efficacy and Safety Profile of Montgomery T-Tube Implantation in Patients with Tracheal Stenosis

Background

Tracheal stenosis is able to lead to airway obstruction.

Objective

To evaluate the efficacy and safety profile of Montgomery T-tube implantation in patients with tracheal stenosis.

Methods

Fifty-two patients with tracheal stenosis diagnosed between 2016 and 2019 were included in this retrospective cohort study. The patients were divided into observation group (n = 25 cases) and control group (n = 27). The therapeutic effect, arterial blood gas analysis, arterial oxygen partial pressure (PaO₂), arterial carbon dioxide partial pressure (PaCO₂), shortness of breath score, airway diameter change, dyspnea score, quality of life, and safety were compared between the two groups before and after treatment.

Results

The therapeutic effect of the observation group gained better results than that of the control group (84.00% vs. 62.96%). One week after operation, the pH value, SaO₂, PaCO₂, shortness of breath score, airway diameter change, dyspnea score, life quality, and incidence of postoperative complications in the observation group exerted better results as compared to the control group.

Conclusion

The implantation of Montgomery T-tube has effective function in terms of improving the symptoms of dyspnea and the life quality of patients with safety profile in patients harboring tracheal stenosis.

Indications and postoperative outcomes of surgery for laryngotracheal stenosis: A descriptive study

OBJECTIVE

Tracheal reconstruction is a rare surgical procedure and the actual incidence of or indications for this procedure have not been thoroughly elucidated. We performed the nationwide database analysis to clarify the real-world situation of laryngotracheal surgery requiring cervical tracheal reconstruction.

METHODS

Patients who underwent surgical treatment for laryngotracheal stenosis or defect from 2008 to 2016 were identified from the Diagnosis Procedure Combination inpatient database, collected from 270 acute care hospitals in Japan. Patients were divided into two groups based on presence/absence of malignancy, and T-tube or tracheotomy dependence at 6 months after surgery was compared between the two groups.

RESULTS

One hundred and thirty-four patients (75 males) were identified. The median age at surgery was 65.5 years. The most common indication for surgery was malignancy (n = 60, 44.8%), followed by iatrogenic (n = 25, 18.6%), trauma (n = 6, 4.5%), malformation of the larynx and trachea (n = 6, 4.5%), and chronic inflammatory disease (n = 4, 2.8%). Thyroid cancer was the most common malignancy (n = 38). Thirty patients (22.4%) failed to decannulate within 6 months and malignancy was associated with a lower dependence on T-tube or tracheotomy at 6 months after surgery (adjusted odds ratio: 0.25, 95% confidence interval: 0.08-0.79).

CONCLUSION

A Japanese health insurance claims database provided a useful overview of the clinical features and outcomes of patients who underwent cervical tracheal reconstruction surgery for laryngotracheal stenosis or defect.

Involvement of Laryngopharyngeal Reflux in Select Nonfunctional Laryngeal Diseases: A Systematic Review

Objectives

To investigate the existing published evidence supporting the role of laryngopharyngeal reflux (LPR) in the development of the select nonfunctional laryngeal diseases of laryngotracheal stenosis, granuloma, leukoplakia, and laryngeal infections

Data Sources

PubMed, Cochrane Library, and Scopus.

Review Methods

A systematic review was performed by 3 independent investigators for studies providing information about the prevalence and role of LPR in the development of laryngotracheal stenosis, granuloma, leukoplakia, and laryngeal infections. Diagnostic criteria and clinical outcome evaluation of included studies were analyzed with PRISMA criteria.

Results

Of the 64 relevant publications, 27 clinical and 4 basic science studies were included. Ten studies used objective reliable examinations for LPR diagnosis (eg, dual- or triple-probe or oropharyngeal pH monitoring, multichannel intraluminal impedance–pH monitoring, or pepsin detection). According to the bias analysis and the results of studies, the association between LPR and laryngotracheal stenosis, leukoplakia, laryngeal papillomatosis, or vocal fold granuloma remains poorly demonstrated. There is a notable heterogeneity among included studies regarding their inclusion criteria, diagnostic methods, and clinical outcome evaluation. Although some experimental findings support the involvement of bile salts and other gastroduodenal proteins active in alkaline pH, no included clinical studies assessed the role of nonacid and mixed reflux through multichannel intraluminal impedance–pH monitoring.

Conclusion

The involvement of LPR in the development of leukoplakia, laryngotracheal stenosis, vocal fold granuloma, and laryngeal papillomatosis is currently not demonstrated. The potential relationship between LPR and these select nonfunctional laryngeal diseases must be confirmed through future clinical and experimental studies considering acid, nonacid, and mixed LPR.