Tracheomalacia and Tracheobronchomalacia in Children and Adults

Endotypes of Prematurity and Phenotypes of Bronchopulmonary Dysplasia: Toward Personalized Neonatology

Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, is increasingly recognized as the consequence of a pathological reparative response of the developing lung to both antenatal and postnatal injury. According to this view, the pathogenesis of BPD is multifactorial and heterogeneous with different patterns of antenatal stress (endotypes) that combine with varying postnatal insults and might distinctively damage the development of airways, lung parenchyma, interstitium, lymphatic system, and pulmonary vasculature. This results in different clinical phenotypes of BPD. There is no clear consensus on which are the endotypes of prematurity but the combination of clinical information with placental and bacteriological data enables the identification of two main pathways leading to birth before 32 weeks of gestation: (1) infection/inflammation and (2) dysfunctional placentation. Regarding BPD phenotypes, the following have been proposed: parenchymal, peripheral airway, central airway, interstitial, congestive, vascular, and mixed phenotype. In line with the approach of personalized medicine, endotyping prematurity and phenotyping BPD will facilitate the design of more targeted therapeutic and prognostic approaches.

A two-stage in vivo approach for implanting a 3D printed tissue-engineered tracheal replacement graft: A proof of concept

OBJECTIVES

To optimize a 3D printed tissue-engineered tracheal construct using a combined in vitro and a two-stage in vivo technique.

METHODS

A 3D-CAD (Computer-aided Design) template was created; rabbit chondrocytes were harvested and cultured. A Makerbot Replicator™ 2x was used to print a polycaprolactone (PCL) scaffold which was then combined with a bio-ink and the previously harvested chondrocytes. In vitro: Cell viability was performed by live/dead assay using Calcein A/Ethidium. Gene expression was performed using quantitative real-time PCR for the following genes: Collagen Type I and type II, Sox-9, and Aggrecan. In vivo: Surgical implantation occurred in two stages: 1) Index procedure: construct was implanted within a pocket in the strap muscles for 21 days and, 2) Final surgery: construct with vascularized pedicle was rotated into a segmental tracheal defect for 3 or 6 weeks. Following euthanasia, the construct and native trachea were explanted and evaluated.

RESULTS

In vitro: After 14 days in culture the constructs showed >80% viable cells. Collagen type II and sox-9 were overexpressed in the construct from day 2 and by day 14 all genes were overexpressed when compared to chondrocytes in monolayer.

IN VIVO

By day 21 (immediately before the rotation), cartilage formation could be seen surrounding all the constructs. Mature cartilage was observed in the grafts after 6 or 9 weeks in vivo.

CONCLUSION

This two-stage approach for implanting a 3D printed tissue-engineered tracheal replacement construct has been optimized to yield a high-quality, printable segment with cellular growth and viability both in vitro and in vivo.

Reassessing the role of tracheobronchomalacia in persistent wheezing

BACKGROUND

Tracheobronchomalacia (TBM) is often manifested as wheezing. Reassessing the role of TBM in persistent wheezing in children is essential.

METHODS

We selected children who were diagnosed with TBM by bronchoscopy and who underwent bronchoscopic reexamination for persistent wheezing or chronic cough between January 2009 and July 2019. The clinical and bronchoscopy data were collected and retrospectively reviewed. For statistical analysis, we used the Kaplan-Meier method, Kruskal-Wallis test, and Fisher exact test.

RESULTS

A total of 79 patients (57 males and 22 females) were included. The median age of the first TBM diagnosis was 7 (interquartile [IQR] 4-11) months. The median age of the first wheezing episode was 4 (IQR 3-7) months. During the time interval between the two bronchoscopies, malacia lesions resolved in 50 patients (63.3%), improvement was seen in 14 patients (17.7%), no change was observed in 11 patients (13.9%), and the condition was aggravated in 4 patients (5.1%). The malacia lesions in 37 patients resolved before 2 years of age. Among the 50 resolved patients, 22 patients (44.0%) reported wheezing three times or more between bronchoscopy evaluations, and 13 of these 22 patients (59.1%) with atopy or family history of allergic diseases were ultimately diagnosed with bronchial asthma.

CONCLUSIONS

In children with persistent wheezing, the role of TBM should be reassessed, especially in those with atopy or family history of allergic diseases, and bronchial asthma should be considered early.

The Feasibility of a Machine Learning Approach in Predicting Successful Ventilator Mode Shifting for Adult Patients in the Medical Intensive Care Unit

Background and Objectives: Traditional assessment of the readiness for the weaning from the mechanical ventilator (MV) needs respiratory parameters in a spontaneous breath. Exempted from the MV disconnecting and manual measurements of weaning parameters, a prediction model based on parameters from MV and electronic medical records (EMRs) may help the assessment before spontaneous breath trials. The study aimed to develop prediction models using machine learning techniques with parameters from the ventilator and EMRs for predicting successful ventilator mode shifting in the medical intensive care unit. Materials and Methods: A retrospective analysis of 1483 adult patients with mechanical ventilators for acute respiratory failure in three medical intensive care units between April 2015 and October 2017 was conducted by machine learning techniques to establish the predicting models. The input candidate parameters included ventilator setting and measurements, patients’ demographics, arterial blood gas, laboratory results, and vital signs. Several classification algorithms were evaluated to fit the models, including Lasso Regression, Ridge Regression, Elastic Net, Random Forest, Extreme Gradient Boosting (XGBoost), Support Vector Machine, and Artificial Neural Network according to the area under the Receiver Operating Characteristic curves (AUROC). Results: Two models were built to predict the success shifting from full to partial support ventilation (WPMV model) or from partial support to the T-piece trial (sSBT model). In total, 3 MV and 13 nonpulmonary features were selected for the WPMV model with the XGBoost algorithm. The sSBT model was built with 8 MV and 4 nonpulmonary features with the Random Forest algorithm. The AUROC of the WPMV model and sSBT model were 0.76 and 0.79, respectively. Conclusions: The weaning predictions using machine learning and parameters from MV and EMRs have acceptable performance. Without manual measurements, a decision-making system would be feasible for the continuous prediction of mode shifting when the novel models process real-time data from MV and EMRs.

Semiquantitative Chest Computed Tomography Assessment Identifies Expiratory Central Airway Collapse in Symptomatic Military Personnel Deployed to Iraq and Afghanistan

PURPOSE

We noted incidental findings on chest computed tomography (CT) imaging of expiratory central airway collapse (ECAC) in dyspneic patients after military deployment to southwest Asia (mainly Iraq and Afghanistan). We developed a standardized chest CT protocol with dynamic expiration to enhance diagnostic reliability and investigated demographic, clinical, and deployment characteristics possibly associated with ECAC.

MATERIALS AND METHODS

We calculated ECAC in 62 consecutive post-9/11 deployers with dyspnea who underwent multi-detector chest CT acquisition. ECAC was defined as ≥70% reduction in the cross-sectional tracheal area at dynamic expiration. We compared demographics (age, smoking, body mass index), comorbid conditions (gastroesophageal reflux, obstructive sleep apnea [OSA]), and clinical findings (air trapping, forced expiratory volume in 1 second percent predicted) in deployers with and without ECAC. We examined associations between ECAC and forced expiratory volume in 1 second percent predicted, air trapping, OSA, deployment duration, and blast exposure.

RESULTS

Among 62 consecutive deployers with persistent dyspnea, 37% had ECAC. Three had severe (>85%) collapse. Those with ECAC were older (mean age 46 vs. 40 y, P=0.02), but no other demographic or clinical characteristics were statistically different among the groups. Although not statistically significant, ECAC odds were 1.5 times higher (95% confidence interval: 0.9, 2.5) for each additional year of southwest Asia deployment. Deployers with ECAC had 1.6 times greater odds (95% confidence interval: 0.5, 4.8) of OSA.

CONCLUSIONS

Findings suggest that ECAC is common in symptomatic southwest Asia deployers. Chest high-resolution CT with dynamic expiration may provide an insight into the causes of dyspnea in this population, although risk factors for ECAC remain to be determined. A standardized semiquantitative approach to CT-based assessment of ECAC should improve reliable diagnosis in dyspneic patients.

Physiotherapy for large airway collapse: an ABC approach

Large airway collapse (LAC) describes the phenomenon of excessive, abnormal, inward movement of the large airways (i.e. trachea and/or main bronchi and/or bronchus intermedius) occurring during the expiratory phase of the respiratory cycle. It is an increasingly well-recognised problem and a prevalent comorbidity in other chronic respiratory conditions (e.g. COPD and asthma). LAC is associated with pervasive respiratory features such as a barking cough, exertional dyspnoea and an increased propensity to lower respiratory tract infection. These symptoms are unpleasant, and patients are often limited in their daily life and their function. The pathophysiology of this condition impairs airway clearance and can cause breathlessness and exercise intolerance, due to a loss of airway patency during expiratory flow. Dysfunctional adaptations to breathing and coughing may further amplify symptoms. This article provides, for the first time, clinically focused physiotherapeutic intervention advice based on our understanding of the pathophysiology of LAC, to support conservative management. It uses the available evidence from LAC, transferable evidence from other conditions and knowledge based on clinical experience. It proposes a practical "ABC model" to ensure physiotherapy assessment and treatments are centred around optimising three key clinical areas: Airways, including airway clearance and cough; Breathing, including breathlessness and breathing pattern; and Capacity for exercise, including an assessment of functional exercise ability.

Clinicopathologic features, comorbid diseases, and prevalence of pulmonary hypertension in dogs with bronchomalacia

Background

Reports of clinicopathologic features of bronchomalacia (BM) differ because of inconsistent definitions and frequent prevalence of comorbid cardiopulmonary disease. Pulmonary hypertension (PH) secondary to BM is poorly described.

Objectives

Dogs with BM will be older but of any somatotype, and increased expiratory effort, ≥1 comorbid disease, and PH will be more common than in dogs without BM.

Animals

Client‐owned dogs (n = 210) evaluated for respiratory signs.

Methods

Medical records of dogs with paired inspiratory: expiratory‐breath‐hold computed tomography, tracheobronchoscopy, or both between January 2016 and December 2019 were retrospectively reviewed. Comparisons between dogs with and without BM using Mann‐Whitney rank sum or χ² tests (P < .05 significant were made). Because of high numbers of variables, criteria with high prevalence (>25%) were identified (n = 10) for univariate analysis (P < .005 significant). Significant variables were submitted for multivariate analysis.

Results

Bronchomalacia was identified in 41% of dogs of all sizes/somatotypes; 38% were >10 kg. All dogs with BM had ≥1 comorbid cardiopulmonary disorder. Dogs with BM were significantly older (P < .001), smaller (P < .001), and were more likely diagnosed with tracheal or mainstem bronchial collapse (P < .001) or bronchiectasis (P < .001). Multivariate analysis confirmed associations with age, tracheal or mainstem bronchial collapse, and bronchiectasis. In dogs with BM, PH was more prevalent.

Conclusions and Clinical Importance

Although significantly more common in older, smaller dogs, BM occurs in dogs of all sizes and in all instances with comorbidities. Echocardiography should be considered in dogs with BM to identify PH.

Anesthesia for pediatric rigid bronchoscopy and related airway surgery: Tips and tricks

Bronchoscopy-guided diagnostic and interventional airway procedures are gaining in popularity and prominence in pediatric surgery. Many of these procedures have been used successfully in the adult population but have not been used in children due to a lack of appropriately sized instruments. Recent technological advances have led to the creation of instruments to enable many more diagnostic and therapeutic procedures to be done under bronchoscopic guidance. These procedures vary significantly in their length and invasiveness and require vastly different anesthetic plans that must be easily adapted to situational and procedural changes. In addition to close communication between the anesthesiology and procedural teams; an understanding of the type of procedure, anesthetic requirements, and potential patient risks is paramount to a successful anesthetic. This review will focus on new rigid bronchoscopic procedures, goals for their respective anesthetic management, and unique tips and trick for how to maintain adequate oxygenation and ventilation in each scenario.

Is secondary tracheomalacia associated with airway inflammation and infection?

BACKGROUND

Recurrent lower respiratory tract infections are among the most prevalent symptoms in secondary tracheomalacia due to mediastinal vascular anomalies (MVAs). It is not known whether this condition could result in persistent lower respiratory tract inflammation and subclinical infection.

METHODS

A retrospective study was performed on records of children with tracheomalacia due to MVAs and recurrent respiratory infections who underwent computed tomography scan, bronchoscopy, and bronchoalveolar lavage (BAL) as part of their clinical evaluation.

RESULTS

Thirty-one children were included in the study: 21 with aberrant innominate artery, four with right aortic arch, one with double aortic arch, and five with aberrant innominate artery associated with right aortic arch. Cytological evaluation of bronchoalveolar lavage fluid showed increased neutrophil percentages and normal lymphocyte and eosinophil proportions. Microorganism growth was detected in 13 BAL samples, with a bacterial load ≥10⁴ colony-forming units/mL in eight (25.8%) of them. Most isolates were positive for Haemophilus influenzae. Bronchiectasis was detected in four children, all with BAL culture positive for H. influenzae. Four patients underwent MVA surgical correction and 27 conservative management, i.e., respiratory physiotherapy in all and high-dose amoxicillin/clavulanic acid (40 mg/kg/day) for 2-4 weeks in those with significant bacterial growth. There was an excellent outcome in most of them.

CONCLUSIONS

Neutrophilic alveolitis is detectable in secondary tracheomalacia but is associated with a clinically significant bacterial load only in a quarter of the patients. Caution should be used regarding inappropriate antibiotic prescriptions to avoid the emergence of resistance, whilst airway clearance maneuvers and infection preventive measures should be promoted.

Synchronous airway lesions in children with severe, progressive and atypical laryngomalacia - Experience of a UK tertiary referral centre

OBJECTIVES

Laryngomalacia is the commonest cause of stridor in the paediatric population. Whilst usually self-limiting, studies have suggested that the presence of synchronous airway lesions (SALs) might be associated with more severe clinical presentation and additional morbidity. However, evidence in the literature is scarce, contributing to controversy regarding the appropriate investigation and management of children with laryngomalacia. The aim of this study was to explore the prevalence, clinical significance and risk factors of SALs in children with severe, progressive and atypical laryngomalacia symptoms.

METHODS

Retrospective analysis of the records of all paediatric patients diagnosed with laryngomalacia in a UK tertiary referral centre, over a 2-year period, was undertaken. Data on demographics, comorbidities, management and presence of SALs were collected.

RESULTS

The study included 130 patients with laryngomalacia. Seventy-eight patients required investigation with microlaryngobronchoscopy (MLB), based on clinical presentation. SALs were identified in 22 patients (28.2%), 6 of which (7.7%) required surgical intervention. The commonest airway lesions included tracheomalacia, bronchomalacia and subglottic stenosis. A correlation between the presence of neurodevelopmental conditions in children and SALs was noted (p value < 0.05). The presence of SALs was not associated with sex, gestational age at birth or other medical comorbidities.

CONCLUSION

The results of this study allow professionals to counsel families about the utility of MLB in children with severe, progressive and atypical laryngomalacia symptoms and inform management pathways for clinicians not working in airway centres. We support the clinical practice that progressive, atypical or severe laryngomalacia symptoms should prompt consideration of an MLB, to identify potential synchronous airway lesions. Furthermore, we propose that a higher index of suspicion and more thorough investigation might be indicated in children with neurodevelopmental disorders.

Respiratory manifestations in the Ehlers-Danlos syndromes

Persons with the Ehlers-Danlos syndromes (EDS) report a wide range of respiratory symptoms, most commonly shortness of breath, exercise limitation, and cough. Also reported are noisy breathing attributed to asthma, difficulty with deep inhalation, and inspiratory thoracic pain. The literature consists of case reports and small cross-sectional and cohort studies. One case-control study estimated twofold to threefold greater respiratory disease burden among persons with EDS as compared to controls. The differential diagnosis for symptoms is broad. Structural alterations include pectus deformities, scoliosis, recurrent rib subluxations, and tracheobronchomalacia, associated with varying degrees of physiologic impairment. Those with vascular EDS have an increased risk of pneumothorax, intrapulmonary bleeding, cysts, and nonmalignant fibrous nodules. Functional aerodigestive manifestations such as inducible laryngeal obstruction may be misdiagnosed as asthma, with gastro-esophageal dysmotility and reflux as common contributing factors. Inflammatory manifestations include costochondritis, bronchiectasis, and localized respiratory allergic and nonallergic mast cell activation. Cranio-cervical instability can dysregulate respiratory control pathways. There is a need for careful phenotyping using standardized clinical tools and patient-reported outcomes and continuing collaboration with aerodigestive specialists including otolaryngologists and gastroenterologists. Also needed is further evaluation of respiratory symptoms in persons with hypermobility spectrum disorders. Personalized monitoring strategies are invaluable for interpretation and long-term management of respiratory symptoms.

Neonates With Tracheomalacia Generate Auto-Positive End-Expiratory Pressure via Glottis Closure

BACKGROUND

In pediatrics, tracheomalacia is an airway condition that causes tracheal lumen collapse during breathing and may lead to the patient requiring respiratory support. Adult patients can narrow their glottis to self-generate positive end-expiratory pressure (PEEP) to raise the pressure in the trachea and prevent collapse. However, auto-PEEP has not been studied in newborns with tracheomalacia. The objective of this study was to measure the glottis cross-sectional area throughout the breathing cycle and to quantify total pressure difference through the glottis in patients with and without tracheomalacia.

RESEARCH QUESTION

Do neonates with tracheomalacia narrow their glottises? How does the glottis narrowing affect the total pressure along the airway?

STUDY DESIGN AND METHODS

Ultrashort echo time MRI was performed in 21 neonatal ICU patients (11 with tracheomalacia, 10 without tracheomalacia). MRI scans were reconstructed at four different phases of breathing. All patients were breathing room air or using noninvasive respiratory support at the time of MRI. Computational fluid dynamics simulations were performed on patient-specific virtual airway models with airway anatomic features and motion derived via MRI to quantify the total pressure difference through the glottis and trachea.

RESULTS

The mean glottis cross-sectional area at peak expiration in the patients with tracheomalacia was less than half that in patients without tracheomalacia (4.0 ± 1.1 mm2 vs 10.3 ± 4.4 mm2; P = .002). The mean total pressure difference through the glottis at peak expiration was more than 10 times higher in patients with tracheomalacia compared with patients without tracheomalacia (2.88 ± 2.29 cm H2O vs 0.26 ± 0.16 cm H2O; P = .005).

INTERPRETATION

Neonates with tracheomalacia narrow their glottises, which raises pressure in the trachea during expiration, thereby acting as auto-PEEP.

Clinical characteristics of children with airway malacia complicated by pneumonia

Background

Airway malacia is an important cause of noisy breathing, recurrent wheezing and respiratory infections, chronic coughing, and episodes of respiratory distress in young children. As the clinical manifestations of airway malacia are not common, many clinicians have insufficient understanding of this disease. So the purpose of this study is to summarize the pathogenic bacteria and clinical manifestations of airway softening complicated with pneumonia in children.

Methods

Children hospitalized with airway malacia complicated by pneumonia were eligible for enrollment from January 1, 2013 to December 31, 2019. Medical records of patients were reviewed for etiology, clinical characteristics, and laboratory examination results.

Results

A total of 164 pneumonia patients with airway malacia were admitted. The male-to-female ratio was 3:1. The age of patients ranged from 1 month to 4 years old. The median age was 6 (3–10) months. The most commonly detected pathogen were Mycoplasma pneumoniae (25/164, 15.24%), Streptococcus pneumoniae (18/164, 10.98%), and respiratory syncytial virus (16/164, 9.76%). Common signs among the 164 patients with confirmed airway malacia included cough (98.78%), wheezing (67.07%), fever (35.37%), intercostal retractions (23.17%), dyspnea (10.98%), cyanosis (11.11%), and crackles (50%). Compared with those without airway malacia, the incidence of premature delivery and mechanical ventilation was higher, and the duration of symptoms before admission (median, 13.5 d) and hospital stay (median 10.0 d) were longer. Of the children with pneumonia, 11.59% of those with airway malacia required supplemental oxygen compared with 4.88% of those without airway malacia (p < 0.05).

Conclusion

The median age of children with airway malacia was 6 months. The most common pathogen in patients with airway malacia complicated by pneumonia was Mycoplasma pneumoniae. Patients with airway malacia complicated by pneumonia often presented with a longer disease course, more severe symptoms, and had delayed recovery.

Obese Patients Undergoing Tracheobronchoplasty Have Excellent Outcomes

BACKGROUND

Tracheobronchoplasty (TBP) is the gold-standard treatment for severe symptomatic excessive central airway collapse (ECAC), however outcomes among obese patients are unknown.

METHODS

A retrospective, single-center analysis was conducted on consecutive patients undergoing TBP for severe symptomatic ECAC from 2003 to 2020. Demographics, comorbidities, functional status, and peri-operative complications were collected. Functional status was assessed with a six-minute walk test (6MWT). Health-related quality of life (HRQOL) was assessed with the St. George's Respiratory Questionnaire (SGRQ), Cough-Specific Quality of Life Questionnaire (CSQL), and modified Medical Research Council dyspnea scale (mMRC) at baseline and post-operatively. Wilcoxon rank-sum and chi-squared tests were used to compare outcomes between groups. A mixed-effects regression model compared 6MWT and HRQOL over time.

RESULTS

One-hundred and three patients underwent TBP with complete follow-up data. Thirty-four patients (33%) were obese (BMI ≥ 35 kg/m²). Baseline demographics were similar between obese and non-obese groups, however obese patients had worse pre-operative SGRQ and mMRC. Overall complication rates were similar (52.9% vs. 43.5%, p=0.36). At 3-months, there was no significant difference in SGRQ, CSQL, or 6MWT, however, mMRC was higher in obese patients (p=0.04). At 12 months, there was no significant difference in SGRQ, CSQL, mMRC, or 6MWT. Correcting for age, sex, and Charlson Comorbidity Index, a mixed-effects regression model demonstrated obesity was not an independent predictor for lower 6MWT or HRQOL.

CONCLUSIONS

Obese patients achieve similar improvement in HRQOL and functional capacity with comparable morbidity following TBP as non-obese patients. Obesity should not preclude patients with severe symptomatic ECAC from TBP.

Endoscopically Applied Biodegradable Stent in a Rabbit Model of Pediatric Tracheomalacia

OBJECTIVES

A polydioxanone (PDO) stent was developed to treat tracheomalacia in pediatric patients. However, its safety and efficacy need to be verified in animal studies before clinical trials in patients can be conducted. This study evaluated the safety and efficacy of a PDO stent in normal and tracheomalacia-model rabbits.

METHODS

In total, 29 New Zealand white rabbits were used: 13 for evaluating the biocompatibility of the PDO stent in normal rabbits and 16 for the creation of a tracheomalacia model. The tracheomalacia model was successfully established in 12 rabbits, and PDO stents were placed in eight of those rabbits.

RESULTS

The PDO stent was successfully positioned in the trachea of the normal rabbits using an endoscopic approach, and its degradation was observed 10 weeks later. The stent fragments did not induce distal airway obstruction or damage, and the mucosal changes that occurred after stent placement were reversed after degradation. The same procedure was performed on the tracheomalacia-model rabbits. The survival duration of the tracheomalacia rabbits with and without stents was 49.0±6.8 and 1.0±0.8 days, respectively. Thus, the PDO stent yielded a significant survival gain (P=0.001). In the tracheomalacia rabbits, stent degradation and granulation tissue were observed 7 weeks after placement, leading to airway collapse and death.

CONCLUSION

We successfully developed a PDO stent and an endoscopic guide placement system. The degradation time of the stent was around 10 weeks in normal rabbits, and its degradation was accelerated in the tracheomalacia model. The mucosal changes associated with PDO stent placement were reversible. Placement of the PDO stent prolonged survival in tracheomalacia-model rabbits.

[Airway complications after lung transplantation]

Lung transplantations have been regularly performed in the Russian Federation since 2010. Therefore, the number of lung transplant recipients, as well as the number of patients with airway complications following lung transplantation has been increasing. Treatment of these patients takes place not only in transplantation centers, but also in other hospitals. This review is devoted to risk factors, clinical manifestations, treatment and prevention of airway complications after lung transplantation. We analyzed literature data over the last 15 years. It was confirmed that bronchoscopy is a «gold standard» for diagnosis of airway complications while bronchoscopic interventions are preferred for treatment. Balloon and rigid bronchodilation and endoscopic airway stenting are the most effective interventions. Silicone stents are the most optimal. Antimicrobial prophylaxis and timely use of antiproliferative immunosuppressive drugs are important factors in prevention and treatment of airway complications after lung transplantation.

Airway Malacia: Clinical Features and Surgical Related Issues, a Ten-Year Experience from a Tertiary Pediatric Hospital

Background: Few studies have been carried out with the aim of describing the clinical course and follow-up of patients with tracheomalacia. We aim to describe the symptoms at diagnosis and the post-treatment clinical course of patients affected by airway malacia. Methods: We retrospectively analyzed characteristics of pediatric patients with a diagnosis of airway malacia. Patients were classified into three groups: bronchomalacia (BM), tracheomalacia (TM) and tracheo-bronchomalacia (TBM). Demographic and clinical data, diagnostic work-up and surgical treatment were recorded. Results: 13/42 patients were affected by congenital syndromes (30.9%). Esophageal atresia with or without tracheal-esophageal fistula (EA/TEF) was detected in 7/42 patients (16.7%). Cardiovascular anomalies were found in 9/42 (21.4%) and idiopathic forms in 13/42 (30.9%). BM occurred in 7/42 (16.6%), TM in 23/42 (54.7%) and TBM in 12/42 (28.6%). At the diagnosis stage, a chronic cough was reported in 50% of cases with a higher prevalence in EA/TEF (p = 0.005). Surgery was performed in 16/42 (40%) of children. A chronic cough and acute respiratory failure were correlated to the need for surgery. During follow-up, there was no difference in persistence of symptoms between conservative vs surgical treatment (p = 0.47). Conclusion: the management of tracheomalacia remains a challenge for pediatricians. Clinical manifestations, such as a barking cough and acute respiratory failure may suggest the need for surgery. Follow-up is crucial, especially in those patients affected by comorbidities, so as to be able to manage effectively the possible persistence of symptoms, including those that may continue after surgical treatment.

Robotic-assisted tracheobronchoplasty: Quality of life and pulmonary function assessment on intermediate follow-up

OBJECTIVE

The initial description of robotic tracheobronchoplasty for the treatment of tracheobronchomalacia demonstrated feasibility, safety, and short-term symptomatic and functional improvement. The purpose of the current study was to demonstrate intermediate outcomes in postoperative pulmonary function and quality of life after robotic tracheobronchoplasty.

METHODS

We retrospectively reviewed prospectively collected clinical data from 42 patients who underwent robotic tracheobronchoplasty from May 2016 to December 2017. The Institutional Review Board or equivalent ethics committee of the Northwell Health approved the study protocol and publication of data. Patient written consent for the publication of the study data was waived by the Institutional Review Board.

RESULTS

A total of 42 patients underwent robotic tracheobronchoplasty during the study period. Median total follow-up is 40 months. There was 1 death since surgery from an unrelated disease. Significant decreases in St George's Respiratory Questionnaire total score (preoperative mean: 64.01, postoperative mean: 38.91, P = .002), St George's Respiratory Questionnaire symptom score (preoperative median: 82.6, postoperative median: 43.99, P < .001), and St George's Respiratory Questionnaire impact score (preoperative median: 55.78, postoperative median: 25.95, P < .001) were apparent at a median follow-up of 13 months. Comparison of preoperative and postoperative pulmonary function tests revealed a significant increase in percent predicted forced expiratory volume in 1 second (preoperative median: 74% vs postoperative median: 82%, P = .001), forced vital capacity (preoperative median: 68.5% vs postoperative median: 80.63%, P < .001), and peak expiratory flow (preoperative median: 61.5% vs postoperative median: 75%, P = .02) measured at a median follow-up of 29 months.

CONCLUSIONS

Robotic tracheobronchoplasty is associated with low intermediate-term mortality. Robotic tracheobronchoplasty results in significant improvement in quality of life and postoperative pulmonary function. Longer-term follow-up is necessary to continue to elucidate the effect of robotic tracheobronchoplasty on halting pathologic progression of tracheobronchomalacia and to determine the long-term impact of tracheobronchoplasty on symptomatic and functional improvement.

Mammalian tracheal development and reconstruction: insights from in vivo and in vitro studies

The trachea delivers inhaled air into the lungs for gas exchange. Anomalies in tracheal development can result in life-threatening malformations, such as tracheoesophageal fistula and tracheomalacia. Given the limitations of current therapeutic approaches, development of technologies for the reconstitution of a three-dimensional trachea from stem cells is urgently required. Recently, single-cell sequencing technologies and quantitative analyses from cell to tissue scale have been employed to decipher the cellular basis of tracheal morphogenesis. In this Review, recent advances in mammalian tracheal development and the generation of tracheal tissues from pluripotent stem cells are summarized.

Pediatric Airway Endoscopy: Recommendations of the Society for Pediatric Pneumology

For many decades, pediatric bronchoscopy has been an integral part of the diagnosis and treatment of acute and chronic pulmonary diseases in children. Rapid technical advances have continuously influenced the performance of the procedure. Over the years, the application of pediatric bronchoscopy has considerably expanded to a broad range of indications. In this comprehensive and up-to-date guideline, the Special Interest Group of the Society for Pediatric Pneumology reviewed the most recent literature on pediatric bronchoscopy and reached a consensus on a safe technical performance of the procedure.

Resorbable airway splint, stents, and 3D reconstruction and printing of the airway in tracheobronchomalacia

Tracheobronchomalacia (TBM) is the most common tracheobronchial obstruction. Most cases are mild to moderate; therefore, they do not need surgical treatment. Severe tracheomalacia, however, represents a diagnostic and therapeutic challenge since they are very heterogeneous. In the armamentarium of resources for the treatment of dynamic airway collapse, splints and stents are two underused strategies and yet, they may represent the best alternative in selected cases. Lately, computed tomography 3D reconstruction of the airway has been used for the design of virtual models that can be 3D-printed for the creation of novel devices to address training, simulation, and biotechnological implants for refractory and severe airway malformations. This manuscript examines the role of resorbable stents, splints, and the 3D reconstruction and printing of the pediatric airway in tracheobronchomalacia.

Current concepts in tracheobronchomalacia: diagnosis and treatment

Airway collapse from dynamic tracheobronchomalacia (TBM), static compression from vascular compression, and/or tracheobronchial deformation are challenging conditions. Patients are best assessed and managed by a multidisciplinary team in centers specializing in complex pediatric airway disorders. Suspicion is made through clinical history and physical examination, diagnosis of location and severity by dynamic 3-phase bronchoscopy, and surgical treatment planning by MDCT and other studies as necessary to completely understand the problems. The treatment plan should be patient-based with a thorough approach to the underlying pathology, clinical concerns, and combined abnormalities. Patients should undergo maximum medical therapy prior to committing to other interventions. For those children considered candidates for surgical intervention, all other associated conditions, including vascular anomalies, chest wall deformities, mediastinal lesions, or other airway pathologies, should also be considered. Our preference is to correct the airway lesions at the same operation as other comorbidities, if possible, to prevent multiple reoperations with their attendant increased risks. We also strongly advocate for the use of recurrent laryngeal nerve monitoring in all cases of cervical or thoracic surgery to minimize the risks to vocal cord function and laryngeal sensation. Studies that evaluate the effect of these interventions on the patient and caregiver's quality of life are needed to fully grasp the impact of TBM on this challenging patient population.

Postnatal impact of a prenatally diagnosed double aortic arch

BACKGROUND

A double aortic arch (DAA) is increasingly identified before birth; however, there are no published data describing the postnatal outcome of a large prenatal cohort.

OBJECTIVE

To describe the associations, symptoms and impact of prenatally diagnosed DAA.

METHODS

Retrospective review of consecutive cases seen at two fetal cardiology units from 2014 to 2019. Clinical records including symptoms and assessment of tracheobronchial compression using flexible bronchoscopy were reviewed. Moderate-severe tracheal compression was defined as >75% occlusion of the lumen.

RESULTS

There were 50 cases identified prenatally and 48 with postnatal follow-up. Array comparative genomic hybridisation (aCGH) was abnormal in 2/50 (4%), aCGH was normal in 33/50 (66%) and of those reviewed after birth, 13 were phenotypically normal. After birth, there was a complete DAA with patency of both arches in 8/48 (17%) and in 40/48 (83%) there was a segment of the left arch which was a non-patent, ligamentous connection.Stridor was present in 6/48 (13%) on the day of birth. Tracheo-oesophageal compressive symptoms/signs were present in 31/48 (65%) patients at median age of 59 days (IQR 9-182 days). Tracheal/carinal compression was present in 40/45 (88%) cases. Seven of 17 (41%) asymptomatic cases demonstrated moderate-severe tracheal compression. All morphologies of DAA caused symptoms and morphology type was not predictive of significant tracheal compression (p=0.3).

CONCLUSIONS

Genetic testing should be offered following detection of double aortic arch. Early signs of tracheal compression are common and therefore delivery where onsite neonatal support is available is recommended. Significant tracheal compression may be present even in the absence of symptoms.

Case Series of Arterial Gas Embolism Incidents in U.S. Navy Pressurized Submarine Escape Training From 2018 to 2019

The goal of Pressurized Submarine Escape Training (PSET) is to prepare future submariners for the physical and mental challenges of escaping a disabled submarine and promote proper handling of the Beaufort Ltd Mk 11 Submarine Escape and Immersion Equipment suit. Training participants are only permitted to enter PSET after strict health screening protocols have been met to optimize trainees' safety. Before PSET, trainees are given detailed, one-on-one instruction on proper ascent mechanics by specially trained Navy Dive instructors. Since the reinstatement of PSET by the U.S. Navy, four incidents of arterial gas embolism (AGE) have occurred in submarine trainees with a 10-year period (2009-2019). Of these four incidents, three were observed within a couple months of each other from 2018 to 2019. A comprehensive review of AGE history, epidemiology, dive physiology, pathophysiology, and management was completed. Prompted by the recent incidents relative to the low reported incidence rate of AGE in historical PSET training, reported potential risk factors were compared with better understand potential etiologies of AGE in already medically screened individuals. Risks and benefits of PSET were listed, compared, and analyzed. The relative safety and cost effectiveness of this rigorous form of training was reconfirmed.

A modified surgical technique for aortopexy in tracheobronchomalacia

OBJECTIVES

Tracheobronchomalacia (TBM) is characterized by collapse of trachea, bronchi or both, leading to dyspnoea, expiratory stridor, coughing or recurrent airway infections. Surgical treatment with aortopexy is warranted for severe TBM. We describe a modified aortopexy technique with aortic wall strap sutures that evenly distributes the traction force over the full width of the aortic arch. The aim of this study was to determine the outcomes of this modified anterior aortopexy technique.

METHODS

Retrospective chart review of all patients undergoing aortopexy with aortic wall strap sutures for TBM between January 2010 and June 2020 in 2 tertiary hospitals in the Netherlands.

RESULTS

Twenty-four patients [median age 9 months (interquartile range 2-117 months); 71% male] underwent aortopexy with the modified technique for TBM (52%), tracheomalacia (40%) or bonchomalacia (8%). Aortopexy was successful in 91.7%, defined as relief or decrease of respiratory symptoms and no need for respiratory support. Complications occurred in 8.3% and mortality was 4%.

CONCLUSIONS

Aortopexy with non-absorbable strap sutures seems an effective and safe treatment for severe TBM. This study supports the hypothesis that strap sutures provide a solid and reliable traction force, but future comparative studies should confirm the benefit of strap sutures over conventional techniques.

A 62-year-old man with stridor and dyspnoea

A 62-year-old man, without any past medical history, but a current 10-pack–year smoker, consulted a pulmonologist at the outpatient department for a gradually worsening dyspnoea over 1 year. Dyspnoea occurred first at exercise but, for 1 week, he felt short of breath, even at rest. He also reported a chronic cough with white sputum and frequent blood streaks. His voice was not affected and he had no swallowing difficulties. He lost 4 kg over the previous 3 months, along with a loss of appetite and tiredness. He did not have fever, night sweats, chest pain or choke.

Stridor is a sign of vital emergency that immediately orientates towards a laryngeal or tracheal obstruction. This case report focuses on the management of stridor, which comprises emergency securing of airways and parallel aetiological investigations.https://bit.ly/39CTjOg

Lower airway collapse: Revisiting the definition and clinicopathologic features of canine bronchomalacia

Bronchomalacia (BM) is an inconsistently defined term in dogs, impairing understanding of clinical presentation, therapeutic response and prognosis. Herein the authors propose to clarify the definition of canine bronchomalacia (CBM) as regional to diffuse dynamic airway collapse of segmental and/or subsegmental bronchi with associated clinical signs due to airflow limitation. In contrast to tracheal collapse, mainstem bronchial collapse, and in some cases lobar collapse, CBM requires advanced imaging. Common co-morbid conditions (e.g., chronic bronchitis, mitral valve degenerative disease, etc.) should be identified during a comprehensive diagnostic evaluation. Current empiric treatments advocated in absence of clinical trials documenting efficacy in the dog warrant evaluation, as some (e.g., bronchodilators) may have detrimental effects in certain types of airway collapse in humans. There is no direct treatment for CBM, as defined above, but non-specific therapies and targeted treatment of co-morbid disease may improve clinical signs and quality of life. In this manuscript, the authors provide a review of the different types of airway collapse focusing on CBM, reviewing their definition and etiology, proposing a classification scheme, and discussing clinical signs, diagnostic testing, and treatment. Future studies should focus on both improving understanding of the etiology and natural disease progression of CBM and treatment trials.

Thermoablative Techniques for Excessive Central Airway Collapse: An Ex Vivo Pilot Study on Sheep Tracheal Tissue

BACKGROUND

Tracheobronchoplasty is the definitive treatment for patients with symptomatic excessive central airway collapse. This procedure is associated with high morbidity and mortality rates. Bronchoscopic techniques are an appealing alternative with less morbidity and the ability to apply it in nonsurgical patients. Although thermoablative methods have been proposed as treatment options to induce fibrosis of the posterior tracheobronchial wall, no studies have compared direct histologic effects of such methods. This study compared the effects of electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and argon plasma coagulation (APC) in the tracheobronchial tree in an ex vivo animal model.

METHODS

Four adult sheep cadavers were used for this study. Under flexible bronchoscopy, the posterior tracheal membrane was treated using different power settings on 4 devices. The airways were assessed for the presence of treatment-related histopathologic changes.

RESULTS

Histologic changes observed were that of acute thermal injury including: surface epithelium ablation, collagen fiber condensation, smooth muscle cytoplasm condensation, and chondrocyte pyknosis. No distinct histologic differences in the treated areas among different modalities and treatment effects were observed. APC at higher power settings was the only modality that produced consistent and homogenous thermal injury effects across all tissue layers with no evidence of complete erosion.

CONCLUSION

Although electrocautery, radiofrequency ablation, potassium titanyl phosphate laser, and APC all induce thermal injury of the airway wall, only APC at high power settings achieves this effect without complete tissue erosion, favoring potential regeneration and fibrosis. Live animal studies are now plausible.

Tracheobronchomalacia, Tracheobronchial Compression, and Tracheobronchial Malformations: Diagnostic and Treatment Strategies

Tracheobronchomalacia (TBM) is an excessive dynamic narrowing of the airway that is greatest with increased mediastinal pressure such as coughing, Valsalva, and forced expiration. Airway compression and/or cartilage malformation is a fixed or static narrowing of the airway typically caused by great vessel malposition and/or abnormalities and may also contribute to airway narrowing. Although imprecise and misleading, the term TBM is often used to represent both problems, static and dynamic airway narrowing, which only serves to confuse and may mislead the treatment team into ineffective therapies. The consequences of airway narrowing caused by dynamic TBM and/or static compression includes a range of clinical signs and symptoms, depending on the location, extent, and severity of the airway collapse. All patients with mild to severe TBM benefit from medical management to optimize airway clearance of mucus. The milder cases of TBM may become asymptomatic with this therapy, allowing time for the child to grow and the airway to enlarge without the consequences of recurrent infections. In cases of more severe TBM with clinical sequelae, more aggressive management may be warranted. Multiple options for surgical intervention are available. This article discusses the details of clinical presentation, evaluation, diagnosis, and a variety of treatments.

An unusual case of breathlessness

We present the case of an asthmatic patient who continued to present with breathlessness and received multiple courses of steroids for her presumed asthma exacerbations. After multiple investigations, we made the diagnosis of TBM secondary to relapsing polychondritis. https://bit.ly/3b8Uw1O.

Respiratory subtype of relapsing polychondritis frequently presents as difficult asthma: a descriptive study of respiratory involvement in relapsing polychondritis with 13 patients from a single UK centre

Introduction

Relapsing polychondritis is a rare multisystem vasculitis characterised by recurrent cartilage inflammation. Respiratory involvement, of which tracheobronchomalacia (TBM) is the commonest form, is difficult to treat and is linked to increased mortality. We describe 13 patients with respiratory involvement.

Methods

This is a retrospective study of all the patients with relapsing polychondritis at University Hospitals Coventry and Warwickshire NHS Trust (UHCW), a secondary care provider for ∼500 000. Only patients with respiratory involvement were included in this study.

Results

We identified 13 patients who fulfilled the inclusion criteria. Most patients were identified from the “difficult asthma” clinic. TBM was seen in 11 patients, whilst two patients had pleural effusions which resolved with immunosuppression and one patient had small airways disease. Computed tomography scans (inspiratory and expiratory) and bronchoscopy findings were useful in diagnosing TBM. Pulmonary function testing revealed significant expiratory flow abnormalities. All patients were treated with corticosteroids/disease-modifying anti-rheumatic drugs (DMARDs) and some were given cyclophosphamide or biological agents, although the response to cyclophosphamide (1 out of 4) or biologicals (2 out of 4) was modest in this cohort. Ambulatory continuous positive airway pressure ventilation was successful in four patients.

Conclusions

Relapsing polychondritis may be overlooked in “difficult asthma” clinics with patients having TBM (not asthma) and other features of relapsing polychondritis. Awareness of this condition is crucial to enable early diagnosis and interventions to reduce the risk of life-threatening airway collapse. A number of patients respond well to DMARDs and are able to minimise corticosteroid use.

Tracheobronchomalacia can present as “difficult asthma” and can be associated with relapsing polychondritis. Optimal management of relapsing polychondritis is through medical treatments and support for the damaged airway through positive airway pressure.https://bit.ly/2JGoq23

Noisy Breathing in an Infant: A Case Report

The diagnosis of vascular rings is challenging and may be delayed as symptoms overlap with more common conditions associated with childhood. Underlying genetic associations of this condition remain largely undiscovered. In this report, we present a patient with a double aortic arch and highlight the importance of diagnostic imaging. We also engage in a review of the important genetic considerations.

Changes of intrathoracic trachea with respiration in children: A metrical assessment based on 3D CT models

AIM

To assess the tracheal volume and the effect of respiration through segmentation on CT-scans in children.

MATERIAL AND METHODS

Chest-CT of 100 patients divided into males and females, aged 3-16 years, were retrospectively assessed. Subjects underwent inspiratory and expiratory CT-scans. Tracheal volume was segmented through ITK-SNAP software. Volume, length, anteroposterior, laterolateral diameters, and T1-T10 distance were measured. The percentage ratio between expiratory and inspiratory phases was calculated: significant differences according to sex for inspiratory and expiratory measurements were assessed through a one-way ANCOVA test using T1-T10 distance as covariate (p < 0.05). Differences in percentage changes according to sex and age were assessed through Mann-Whitney test and calculation of Pearson's correlation coefficient, respectively (p < 0.05).

RESULTS

No statistically significant difference according to sex was found for any measurement (p > 0.05). For the percentage ratio between inspiratory and expiratory phase, no difference was found according to sex for any measurement (p > 0.05). The percentage ratio of tracheal volume and length between expiratory and inspiratory phases showed a negative correlation with age (p < 0.05).

CONCLUSIONS

This study provides a novel contribution to the assessment of tracheal size in healthy children: future studies will verify the same measurements in patients affected by tracheomalacia to improve diagnosis.

Advanced Therapies for Severe Tracheobronchomalacia: A Review of the Use of 3D-Printed, Patient-Specific, Externally Implanted, Bioresorbable Airway Splints

Tracheobronchomalacia is a condition of dynamic collapse of the trachea and mainstem bronchi. The clinical significance of tracheobronchomalacia depends on its severity. Mild cases may be medically managed with limited symptomology, while severe cases require advanced therapies, lengthy hospital stays, and carry significant morbidity and mortality. Current therapies for severe tracheobronchomalacia include tracheostomy with prolonged mechanical ventilation, aortopexy, tracheobronchopexy, and intraluminal metallic, silicone, or bioresorbable stents. Three-dimensional (3D)-printed, patient-specific, bioresorbable airway splinting is a novel treatment option that is undergoing investigation in a cohort of critically ill children with severe tracheobronchomalacia. At the time of our last review of our data, 29 splints had been implanted in 15 children with intrathoracic tracheobronchomalacia. The median follow-up was 8.5 months. There were 12 long-term survivors, and all but one lived at home. This article discusses the details of our institution's development and use of 3D-printed, patient-specific, bioresorbable splints for treatment of severe tracheobronchomalacia in the pediatric population.

Single-Lumen Endotracheal Tube and Bronchial Blocker for Airway Management During Tracheobronchoplasty for Tracheobronchomalacia: A Case Report

We present a case of a 69-year-old man who underwent tracheobronchoplasty for tracheobronchomalacia using a single-lumen endotracheal tube and a Y-shaped bronchial blocker for airway management. Tracheobronchoplasty is performed by sewing mesh to plicate the posterior, membranous wall of the distal trachea and main bronchi through a right posterolateral thoracotomy. The goals of airway management include continuous left-lung ventilation and lung protection from aspiration. Ideally, only conventional airway management tools are used. This case demonstrates that a single-lumen endotracheal tube with a bronchial blocker can be a straightforward strategy for airway management during tracheobronchoplasty.

INCIDENCE OF MALNUTRITION, ESOPHAGEAL STENOSIS AND RESPIRATORY COMPLICATIONS AMONG CHILDREN WITH REPAIRED ESOPHAGEAL ATRESIA

Background: Esophageal atresia is congenital anomaly with high mortality. Surgical complications and changes in nutritional status are common problems after surgical correction. Aim: To evaluate nutritional status, esophageal stenosis, and respiratory complications among children who had repaired esophageal atresia.

Incidence of malnutrition, esophageal stenosis and respiratory complications among children with repaired esophageal atresia

Background:

Esophageal atresia is congenital anomaly with high mortality. Surgical complications and changes in nutritional status are common problems after surgical correction.

Aim: T

o evaluate nutritional status, esophageal stenosis, and respiratory complications among children who had repaired esophageal atresia.

Methods:

Children aged >2 months old with repaired esophageal atresia were included in the current study. Gender, age, weight, and height were recorded for each case. Height for age and weight for age were calculated for each case.

Results:

According to weight for length percentile, 41.02% of the cases were underweight. Esophageal stenosis was seen in 54.76% of the obtained esophagograms.

Conclusion:

Underweight was present in 41.02 of the patients according to weight-for-height percentile.

Cleft-lip-plate patient with tracheobronchomalacia: A case report and review of the literature in Japan

Background

Tracheobronchomalacia (TBM) is a severe life-threatening perioperative complication. It is a rare condition caused by congenital and developmental anomalies of the trachea and/or the bronchus. It is often difficult to diagnose TBM before surgery as this congenital disease presents very few symptoms preoperatively and most often appears postoperatively.

Case presentation and Review

The study describes a case of cleft-lip-plate (CL/P) in a 7-month-old Japanese female with TBM and Tetralogy of Fallot syndrome. Before undergoing cleft-lip surgery, her TBM was not fully elucidated by preoperative examinations, and the operation was completed uneventfully. After the surgery, however, she started showing severe respiratory distress and developed hypoxia and bradycardia in the operating room. CPR was performed successfully, but a bronchoscopy revealed a severely collapsed airway, and the pathological condition was diagnosed as TBM occurred postoperatively. Eight months later, she died of sudden respiratory failure similar to that of the postoperative event caused by TBM. A literature review was conducted on the complications of CL/P from 1990 to 2017 in Japan.

Conclusions

It was hypothesized that CL/P with congenital heart disease (CHD) and TBM with CHD may crossover in relatively high rates. Currently, there are very few solutions available to treat severe airway obstruction related to TBM. This highlights the need for preoperative diagnosis of TBM as an important step in overcoming severe airway complications.

A successful surgical tracheobronchoplasty in a case of expiratory collapse of central airways associated with tracheobronchomalacia in a severely deformed single lung patient

A 67-year-old male with a severe body deformity and a total collapse of the left lung due to infantile paralysis was admitted to a regional hospital for a spinal fracture. He suffered from cardiopulmonary arrest during the hospitalization. Although extubation was tried several times after resuscitation, he went into cardiopulmonary arrest repeatedly. The expiratory collapse of the central airways due to tracheobronchomalacia was suspected, requiring tracheostomy with persistent positive pressure ventilation. He was transferred to our hospital after several unsuccessful endobronchial interventions. Severe tracheobronchomalacia was diagnosed with dynamic bronchoscopy, and surgical tracheobronchoplasty using a polypropylene mesh was performed. A modified surgical approach was utilized to stabilize the intraoperative respiratory status in this particular patient with a severely deformed body and a single lung. Consequently, the tracheobronchoplasty was completed without intraoperative complications. The postoperative course was also uneventful, and the patient was ventilator-free on postoperative day 7.

Longstanding tracheobronchomalacia: A forgotten cause of severe cough and its response to roflumilast

This case report describes a patient with moderately severe tracheobronchomalacia following mycoplasma pneumonia. The patient was considered to have obstructive lung disease despite no prior smoking or lung disease and failure to respond to standard treatment. The possibility of tracheal pathology causing cough and sputum was not considered in 23yrs confirming this to be a “forgotten zone”. The patient was treated with Roflumilast to reduce airway secretions with great success and the Immunology of Roflumilast is discussed.

Expiratory central airway collapse - an overlooked entity?: Two case reports

INTRODUCTION

Expiratory central airway collapse is defined by excessive inward bulging of either tracheobronchial posterior membrane or cartilage. The former is called excessive dynamic airway collapse (EDAC), and the latter, depending on the site of collapse, tracheomalacia, bronchomalacia or tracheobronchomalacia. Due to their non-specific symptoms and lack of awareness amongst clinicians they tend to be mislabeled as common obstructive lung disorders, or complicate their course undetected. Particular controversies refer to EDAC sometimes considered just as a symptom of obstructive lung disease and not a separate entity. Nonetheless, a growing body of evidence indicates that EDAC might be present in patients without apparent obstructive lung disease or it might be an independent risk factor in chronic obstructive pulmonary disease or asthma patients.

PATIENT CONCERNS

Patient #1 was admitted because of idiopathic chronic cough whereas patient #2 was admitted for differential diagnosis of dyspnea of uncertain etiology. In both patients symptoms were unresponsive to bronchodilators and inhaled corticosteroids.

FINDINGS AND DIAGNOSIS

In both patients an excess collapse of tracheobronchial posterior membrane was detected during bronchoscopy; in patient #1, of right main bronchus and right upper lobe bronchus and in patient #2 of right upper lobe bronchus and both main bronchi. Excess central airway collapse in patient #2 was also visualized on expiratory chest CT. In patient #1 spirometry did not reveal obturation, whereas in patient #2 only mild, irreversible, obstruction was revealed, disproportionate to patients significant breathlessness.

INTERVENTIONS

Both patients were treated with N-acetylcysteine and adjustable positive expiratory pressure valves.

OUTCOMES

Due to aforementioned treatment chronic cough in patient #1 subsided almost completely whereas patient's #2 dyspnea improved significantly.

CONCLUSIONS

In presented cases EDAC was an unexpected finding, even though, it firmly corresponded with reported symptoms. Treatment modification led to improvement of patients quality of life.

Care recommendations for the respiratory complications of esophageal atresia-tracheoesophageal fistula

Tracheoesophageal fistula (TEF) with esophageal atresia (EA) is a common congenital anomaly that is associated with significant respiratory morbidity throughout life. The objective of this document is to provide a framework for the diagnosis and management of the respiratory complications that are associated with the condition. As there are no randomized controlled studies on the subject, a group of experts used a modification of the Rand Appropriateness Method to describe the various aspects of the condition in terms of their relative importance, and to rate the available diagnostic methods and therapeutic interventions on the basis of their appropriateness and necessity. Specific recommendations were formulated and reported as Level A, B, and C based on whether they were based on "strong", "moderate" or "weak" agreement. The tracheomalacia that exists in the site of the fistula was considered the main abnormality that predisposes to all other respiratory complications due to airway collapse and impaired clearance of secretions. Aspiration due to impaired airway protection reflexes is the main underlying contributing mechanism. Flexible bronchoscopy is the main diagnostic modality, aided by imaging modalities, especially CT scans of the chest. Noninvasive positive airway pressure support, surgical techniques such as tracheopexy and rarely tracheostomy are required for the management of severe tracheomalacia. Regular long-term follow-up by a multidisciplinary team was considered imperative. Specific templates outlining the elements of the clinical respiratory evaluation according to the patients' age were also developed.