Pediatric tracheomalacia

Clinical Outcomes Through Two Years for Infants With Bronchopulmonary Dysplasia and Tracheomalacia

BACKGROUND

Tracheomalacia (TM) is common in infants with bronchopulmonary dysplasia (BPD) and associated with respiratory morbidity. Assessment of TM was historically via bronchoscopy, but recent studies demonstrate that ultrashort echo-time (UTE) magnetic resonance imaging (MRI) can accurately assess TM in neonates.

RESEARCH QUESTION

Do neonates with MRI-identified TM and BPD have increased respiratory morbidity through age 2 years?

METHODS

We performed an observational cohort study of 54 subjects with BPD and assessed TM using UTE MRI at term-equivalent age. TM was defined as an airway minor/major axis ratio (rd,min) of < 0.7. Outcomes through 2 years of life were evaluated via electronic medical record review.

RESULTS

There were 23 subjects (43%) with TM. Modified Ochiai MRI scores were similar between the subjects with and without TM (7.3 ± 4.1 vs. 7.4 ± 4.1). Subjects with TM were more likely to require respiratory support at age 2 years (62% vs. 30%, p = 0.04) and be prescribed systemic corticosteroids (71% vs. 27%, p = 0.004). Most patients with TM were prescribed bronchodilators (90% vs. 60%, p = 0.04). A 10% increase in tracheal collapse correlated with a 28-day increased hospital length of stay (p = 0.047), increased likelihood of pneumonia (p = 0.05), and treatment with antibiotics (p = 0.04) and systemic steroids (p = 0.008).

CONCLUSIONS

TM in the neonatal period was associated with increased respiratory morbidity through age 2 years, demonstrated by increased respiratory support and more frequent usage of systemic corticosteroids and bronchodilators, independent of the severity of BPD. These results highlight the significance of central airway disease in neonates with BPD.

Tracheomalacia and surgical options: A case series perspective

Tracheomalacia causes considerable morbidity in children, and the best treatment options remain debated. This paper presents a case series of seven Danish children who underwent surgical interventions, such as tracheopexy and aortopexy, demonstrating favourable clinical outcomes, notably with early intervention. We discuss the indications, timing and potential benefits of surgery for tracheomalacia in reducing respiratory symptoms caused by tracheal collapse. Our case series highlights the potential of surgical options in managing tracheomalacia, emphasising the need for standardised protocols, multidisciplinary and international collaboration, and further research to optimise treatment strategies and outcomes.

Does primary posterior tracheopexy prevent collapse of the trachea in newborns with oesophageal atresia and tracheomalacia? A study protocol for an international, multicentre randomised controlled trial (PORTRAIT trial)

INTRODUCTION

Tracheomalacia (TM) often occurs in children with oesophageal atresia (OA), leading to recurrent respiratory symptoms and in severe cases to blue spells or ultimately respiratory arrest. In some patients, a secondary posterior tracheopexy may then be indicated. This secondary surgery, as well as respiratory morbidity, may be prevented by performing a primary posterior tracheopexy (PPT) concurrent with primary OA correction. The aim of this trial is to determine if a PPT can decrease-or prevent-tracheal collapse in newborns with OA and TM. Additionally, the trial aims to determine whether the potential observed effect of PPT on tracheal stability is sustained over time.

METHODS AND ANALYSIS

This is an international multicentre double-blind randomised controlled trial. Seventy-eight children with OA type C will be randomised 1:1 into the no-PPT group or PPT group. Randomisation will be stratified by centre. The degree and location of TM are assessed during preoperative, intraoperative and two postoperative tracheobronchoscopies. The occurrence of TM will be evaluated during three routine follow-up consultations until the age of 6 months. The primary outcome is the degree of collapse of the tracheal wall during the intraoperative tracheobronchoscopy (after performing the PPT/no-PPT), measured in percentages. The difference in the mean degree of collapse will be compared between the no-PPT and the PPT groups using linear regression, adjusting for centre and the preoperative degree of tracheal collapse at baseline. The adjusted mean difference will be reported as effect size together with its 95% CI.

ETHICS AND DISSEMINATION

Patients will be included after written parental informed consent. The risks and burden associated with the trial are minimal. The institutional review board of the University Medical Center Utrecht has approved this protocol (METC-number 23-256/A). Results will be shared in a peer-reviewed scientific journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT06335862.

The Value of Preoperative Rigid Tracheobronchoscopy for the Diagnosis of Tracheomalacia in Oesophageal Atresia Patients

BACKGROUND

Oesophageal atresia (OA) is often accompanied by tracheomalacia (TM). The aim of this study was to evaluate its presence in OA patients during routine rigid tracheobronchoscopy (TBS) before primary correction and compare this to postoperative TBS and clinical signs of TM.

METHODS

This retrospective cohort study included patients born with OA between June 2013 and December 2022 who had received a TBS before OA correction and had been followed for at least twelve months. Definite TM was postoperatively diagnosed through TBS, and probable TM was defined as having symptoms of TM.

RESULTS

We analysed data from 79 patients, of whom 87% with OA type C. Preoperatively, TM was observed in 33 patients (42% of all patients), seven of whom had severe TM. Definite TM was observed in 21 patients (27%), of whom 15 had severe TM. Forty-one patients (52% of all patients) had developed symptoms of TM within twelve months, including harsh barking cough (n = 15), stridor and/or wheezing (n = 20), recurrent respiratory insufficiency (n = 11), or needing airway surgery (n = 7). The sensitivity of preoperative TBS for the presence of postoperative (definite and probable combined) TM is 50.0%, 95% CI [35.2-64.8], and the specificity 67.6%, 95% CI [51.7-81.1]. Clinical characteristics did not differ between the patients with or without postoperative TM.

CONCLUSIONS

More than half of the studied patients with OA experienced symptoms of TM. While preoperative TBS is routinely performed prior to surgical OA correction, its predictive value for the presence of postoperative TM remains limited.

LEVEL OF EVIDENCE

Level II.

TYPE OF STUDY

Study of Diagnostics Test.

Correlation of Tracheomalacia Severity With Esophageal Gap Length as Assessed by Ultrashort Echo-time MRI

INTRODUCTION

Tracheomalacia severity is difficult to quantify, however, ultrashort echo-time MRI objectively quantifies tracheomalacia in infants without sedation, radiation, or intubation. Patients with tracheoesophageal fistula and esophageal atresia (TEF/EA) commonly have tracheomalacia, however, the relationship between tracheomalacia severity and esophageal atresia has not been well defined. The primary objective of this study was to establish the relationship between EA and tracheomalacia severity and identify possible predictors of tracheomalacia severity.

METHODS

A retrospective review of neonates with TEF/EA who had previously undergone UTE MRI was performed. The trachea was divided into thirds. Maximal eccentricity in each third was calculated by measuring the anterior posterior dimension (MinD) and dividing it by the maximum width of the trachea (MaxD). Frequency of respiratory related admissions, number of upper respiratory infections, and number of steroids courses were quantified in addition to eccentricity in short and long gap esophageal atresia patients.

RESULTS

A total of 16 TEF/EA patients were included. Patients with long gap esophageal atresia had more severe tracheomalacia than short gap as measured by eccentricity in the upper (0.60 vs 0.72, p = 0.03), middle (0.48 vs 0.61, p = 0.02), and lower (0.5 vs 0.65, p = 0.01) trachea. Long gap esophageal atresia patients had more frequent respiratory readmissions (1.87 admissions/year vs 0.54 admissions/year) (p = 0.03). Following TEF/EA repair the trachea was less eccentric in the upper third (0.64 pre, 0.79 post, p < 0.01) and more eccentric in the lower third (0.69 pre, 0.56 post, p < 0.01).

CONCLUSION

Differences in esophageal gap and repair status correlate with airway eccentricity and tracheomalacia symptoms.

LEVEL OF EVIDENCE: 4

The T-Type Calcium Channel CACNA1H is Required for Smooth Muscle Cytoskeletal Organization During Tracheal Tubulogenesis

Abnormalities of tracheal smooth muscle (SM) formation are associated with several clinical disorders including tracheal stenosis and tracheomalacia. However, the cellular and molecular mechanisms underlying tracheal SM formation remain poorly understood. Here, it is shown that the T-type calcium channel CACNA1H is a novel regulator of tracheal SM formation and contraction. Cacna1h in an ethylnitrosourea forward genetic screen for regulators of respiratory disease using the mouse as a model is identified. Cacna1h mutants exhibit tracheal stenosis, disorganized SM and compromised tracheal contraction. CACNA1H is essential to maintain actin polymerization, which is required for tracheal SM organization and tube formation. This process appears to be partially mediated through activation of the actin regulator RhoA, as pharmacological increase of RhoA activity ameliorates the Cacna1h-mutant trachea phenotypes. Analysis of human tracheal tissues indicates that a decrease in CACNA1H protein levels is associated with congenital tracheostenosis. These results provide insight into the role for the T-type calcium channel in cytoskeletal organization and SM formation during tracheal tube formation and suggest novel targets for congenital tracheostenosis intervention.

Airway Anomalies in Pediatric Patients After Surgery for Congenital Heart Disease: Single-Center Retrospective Cohort Study, Taiwan, 2017-2020

OBJECTIVES

Airway anomalies increase risk of morbidity and mortality in postoperative pediatric patients with congenital heart disease (CHD). We aimed to identify airway anomalies and the association with intermediate outcomes in patients undergoing surgery for CHD.

DESIGN

Single-center, hospital-based retrospective study in Taiwan, 2017-2020.

SETTING

A tertiary referral hospital in Taiwan.

PATIENTS

All pediatric patients who underwent surgery for CHD and were admitted to the PICU and had data about airway evaluation by cardiopulmonary CT scan or bronchoscopy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 820 CHD patients identified as having undergone airway evaluation in the PICU, 185 (22.6%) were diagnosed with airway anomalies, including structural lesions in 146 of 185 (78.9%), and dynamic problems were seen in 87 of 185 (47.0%). In this population, the explanatory factors associated with greater odds (odds ratio [OR]) of airway anomaly were premature birth (OR, 1.90; p = 0.002), genetic syndromes (OR, 2.60; p < 0.001), and in those with preoperative ventilator use (OR, 4.28; p < 0.001). In comparison to those without airway anomalies, the presence of airway anomalies was associated with higher hospital mortality (11.4% vs. 2.7%; p < 0.001), prolonged intubation days (8 d [1-27 d] vs. 1 d [1-5 d]; p < 0.001), longer PICU length of stay (23 d [8-81 d] vs. 7 d [4-18 d]; p < 0.001), and greater hazard of intermediate mortality (adjusted hazard ratio, 2.60; p = 0.001).

CONCLUSIONS

In our single-center retrospective study, 2017-2020, between one-in-five and one-in-four of our postoperative CHD patients undergoing an airway evaluation had airway anomalies. Factors associated with greater odds of airway anomaly included, those with premature birth, or genetic syndromes, and preoperative ventilator use. Overall, in patients undergoing airway evaluation, the finding of an airway anomalies was associated with longer postoperative intubation duration and greater hazard of intermediate mortality.

Usefulness of lateral-anteroposterior dimeter ratio in patients with tracheomalacia associated with esophageal atresia

PURPOSE

Tracheomalacia (TM) is commonly associated with esophageal atresia (EA) and compression by the brachiocephalic artery is a factor for TM. Previous research has focused on the lateral-to-anteroposterior tracheal diameter ratio (LAR). This study aimed to assess the LAR and postoperative outcomes of EA patients.

METHODS

Patients undergoing thoracoscopic repair for EA between March 2020 and October 2023 were enrolled. Posterior tracheopexy (PT) was performed during thoracoscopic repair of EA on patients with bronchoscopy-confirmed TM; clinical courses and LAR were retrospectively analyzed.

RESULTS

Overall, 18 patients were enrolled; 14 patients underwent PT. Their median preoperative and postoperative LARs were 2.26 and 1.50, respectively; this difference was statistically significant. Four patients without TM did not undergo PT and their median LAR was 1.59. Median LAR for patients without PT was lower than that of preoperative patients with PT and no statistical differences were observed from that of postoperative patients with PT. The patients whose LAR improved with PT did not require further surgical intervention for TM. One patient who had a postoperative LAR of 2.25 required external tracheal stenting.

CONCLUSION

LAR is a useful index for determining the severity of TM associated with EA. LAR can reflects the efficacy of PT.

Outcomes of surgical treatment of tracheobronchomalacia in children

BACKGROUND

Tracheobronchomalacia (TBM) is characterized by excessive dynamic airway collapse. Severe TBM can be associated with substantial morbidity. Children with secondary TBM associated with esophageal atresia/tracheoesophageal fistula (EA/TEF) and vascular-related airway compression (VRAC) demonstrate clinical improvement following airway pexy surgery. It is unclear if children with severe primary TBM, without secondary etiologies (EA/TEF, vascular ring, intrinsic pulmonary pathology, or complex cardiac disease) demonstrate clinical improvement following airway pexy surgery.

MATERIALS AND METHODS

The study cohort consisted of 73 children with severe primary TBM who underwent airway pexy surgery between 2013 and 2020 at Boston Children's Hospital. Pre- and postoperative symptoms as well as bronchoscopic findings were compared with Fisher exact test for categorical data and Student's t-test for continuous data.

RESULTS

Statistically significant improvements in clinical symptoms were observed, including cough, noisy breathing, prolonged respiratory infections, pneumonias, exercise intolerance, cyanotic spells, brief resolved unexplained events (BRUE), and noninvasive positive pressure ventilation (NIPPV) dependence. No significant differences were seen regarding oxygen dependence, ventilator dependence, or respiratory distress requiring NIPPV. Comparison of pre- and postoperative dynamic bronchoscopy findings revealed statistically significant improvement in the percent of airway collapse in all anatomic locations except at the level of the upper trachea (usually not malacic). Despite some initial improvements, 21 (29%) patients remained symptomatic and underwent additional airway pexies with improvement in symptoms.

CONCLUSION

Airway pexy surgery resulted in significant improvement in clinical symptoms and bronchoscopic findings for children with severe primary TBM; however, future prospective and long-term studies are needed to confirm this benefit.

Surgical treatment for severe pediatric tracheobronchomalacia: the 20-year experience of a single center

OBJECTIVE

In children with tracheobronchomalacia, surgical management should be reserved for the most severe cases and be specific to the type and location of tracheobronchomalacia. The goal of this study is to describe the presentation and outcomes of children with severe tracheobronchomalacia undergoing surgery.

METHODS

Retrospective case series of 20 children operated for severe tracheobronchomalacia at a tertiary hospital from 2003 to 2023. Data were collected on symptoms age at diagnosis, associated comorbidities, previous surgery, age at surgery, operative approach, time of follow-up, and outcome. Surgical success was defined as symptom improvement.

RESULTS

The most frequent symptoms of severe tracheobronchomalacia were stridor (50 %), cyanosis (50 %), and recurrent respiratory infections (45 %). All patients had one or more underlying conditions, most commonly esophageal atresia (40 %) and prematurity (35 %). Bronchoscopy were performed in all patients. Based on etiology, patients underwent the following procedures: anterior aortopexy (n = 15/75 %), posterior tracheopexy (n = 4/20 %), and/or posterior descending aortopexy (n = 4/20 %). Three patients underwent anterior aortopexy and posterior tracheopexy procedures. After a median follow-up of 12 months, 16 patients (80 %) had improvement in respiratory symptoms. Decannulation was achieved in three (37.5 %) out of eight patients with previous tracheotomy. The presence of dying spells at diagnosis was associated with surgical failure.

CONCLUSIONS

Isolated or combined surgical procedures improved respiratory symptoms in 80 % of children with severe tracheobronchomalacia. The choice of procedure should be individualized and guided by etiology: anterior aortopexy for anterior compression, posterior tracheopexy for membranous intrusion, and posterior descending aortopexy for left bronchus obstruction.

Update on aortopexy and posterior tracheopexy for tracheomalacia in patients with esophageal atresia

Despite improving the survival after repair of esophageal atresia (EA), the morbidity of EA repair remains high. Specifically, tracheomalacia (TM) is one of the most frequent complications of EA repair. Continuous positive airway pressure is generally applied for the treatment of TM. However, surgical intervention is required against an apparent life-threatening event or inability to perform extubation for a long period. According to our review, most cases of TM showed symptom improvement after aortopexy. The ratio of the trachea's lateral and anterior-posterior diameter at the brachiocephalic artery crossing the trachea, which reflects the compression of the trachea by the brachiocephalic artery, is a good indicator of aortopexy. Our finding suggests that most TM cases associated with EA may not be caused by tracheal fragility alone, but may involve blood vessel compression. Posterior tracheopexy (PT) is also an effective treatment for TM. Recently, open or thoracoscopic PT was able to be performed simultaneously with EA repair. In many cases, aortopexy or PT is a safe and effective surgical treatment for TM with EA. Other surgical procedures, such as external stenting, should be considered for patients with diffuse-type TM for whom aortopexy and PT appear relatively ineffective.

Dynamic airway computed tomography and flexible bronchoscopy for diagnosis of tracheomalacia in children: A comparison study

INTRODUCTION

Tracheomalacia (TM) is an important cause of respiratory morbidity. Dynamic flexible bronchoscopy is considered the gold standard for diagnosis. Dynamic airway computed tomography (DACT) is a low radiation, noninvasive diagnostic tool utilizing images obtained continuously over several respiratory cycles. We aimed to assess the accuracy of DACT in TM diagnosis.

METHODS

Retrospective analysis of all patients who underwent both DACT and flexible bronchoscopy within 6 months. Airway anterior-posterior (AP) diameter was measured on multiplanar reconstructions CT in both the inspiratory and expiratory phases. Using still images from the bronchoscopy videos, the AP diameter of the trachea was measured at points of maximal and minimal diameter during tidal breathing. Degree of TM on both DACT and flexible bronchoscopy were graded using a scaling system of 50%-74%, 75%-89%, and 90%-100% as described by the European Respiratory Society.

RESULTS

Twenty-four patients met inclusion criteria with an average time of 19.5 days between CT and bronchoscopy. The specificity and sensitivity of DACT for the overall diagnosis of TM was 100% and 68%, respectively, with a positive predictive value of 100% and a negative predictive value of 62%. There was a strong positive correlation between DACT and flexible bronchoscopy in the measurement of tracheal AP diameter changes (ρ = 0.773, R2 0.597, p = 0.00001). Mean effective radiation dose for DACT was 0.1 mSv.

CONCLUSION

Ultralow dose DACT has excellent specificity and positive predictive value for both detection of TM and categorizing severity of tracheal collapse but is not sufficiently sensitive to rule it out.

Prevalence of tracheobronchomalacia is higher than previously reported in children with cystic fibrosis

BACKGROUND

Tracheobronchomalacia (TBM) is estimated to be present in 1 in 2100 children. Previous reports suggest the prevalence is higher in children with cystic fibrosis (CF). This has clinical implications with potential to influence airway clearance and lung health.

AIM

To determine the prevalence and clinical associations of TBM in Western Australian children with CF.

METHODS

Children with CF born between 2001 and 2016 were included. Operation reports from bronchoscopies performed until the age of 4 were retrospectively reviewed. Data were collected on the presence, persistence defined as a repeat diagnosis, and severity of TBM. Data on genotype, pancreatic status, and symptoms at CF diagnosis were extracted from the medical record. Associations between categorical variables were compared using χ2 and Fisher's exact test.

RESULTS

Of 167 children (79 male), 68 (41%) were diagnosed with TBM at least once, with TBM persistent in 37 (22%) and severe in 31 (19%). TBM was significantly associated with pancreatic insufficiency (χ2  = 7.874, p < 0.05, odds ratio [OR] 3.4), delta F508 gene mutation (χ2  = 6.489, p < 0.05, OR 2.3), and a presentation of meconium ileus (χ2  = 8.615, p < 0.05, OR 5.0). Severe malacia was less likley in females (χ2 = 4.523, p < 0.05, OR 0.42) . No significant relationship was found with respiratory symptoms at the time of CF diagnosis (χ2  = 0.742, p = 0.39).

CONCLUSIONS

TBM was common in this group of children under the age of 4 with CF. A high index of suspicion for airway malacia should be considered in children with CF, particularly those who present with meconium ileus and have gastrointestinal symptoms at diagnosis.

An Ex Vivo Model of Posterior Tracheomalacia With Evaluation of Potential Treatment Modalities

OBJECTIVE

Posterior tracheomalacia (TM) is characterized by excessive intraluminal displacement of the tracheal membranous wall. Recently, novel surgical strategies for repair of posterior TM have been introduced. To our knowledge, these strategies have not been evaluated in a model of posterior TM. Thus, we sought to design an ex vivo mechanical model of posterior TM to evaluate potential repair interventions.

METHODS

A model for posterior TM was created with partial thickness longitudinal incisions to the posterior aspect of ex vivo porcine trachea. Three groups of tracheas were tested: (1) control (unmanipulated), (2) posterior TM (injury), and (3) intervention (repair). Interventions included external splinting with 0.3 and 0.5 mm bioresorbable plates, posterior tracheopexy, and injection tracheoplasty with calcium hydroxylapatite. An airtight tracheal system was created to measure tracheal wall collapse with changes in negative pressure. A bronchoscope and pressure transducer were connected to either end. Cross-sectional area of the tracheal lumen was analyzed using ImageJ software (National Institutes of Health, Bethesda, MD).

RESULTS

Average percent reduction in cross-sectional area of the tracheal lumen was compared using a two-tailed paired t-test. Significant differences were found between control and TM groups (p < 0.019). There was no significant difference between control and external splinting and posterior tracheopexy groups (p > 0.14).

CONCLUSION

We describe an ex vivo model for posterior TM that replicates airway collapse. External splinting and tracheopexy interventions showed recovery of the injured tracheal segment. Injection tracheoplasty did not improve the TM.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:2000-2006, 2023.

Systematic Analysis of Smooth Muscle and Cartilage Ring Formation during Mouse Tracheal Tubulogenesis

The trachea tube is the exclusive route to allow gas exchange between the external environment and the lungs. Recent studies have shown the critical role of mesenchymal cells in tracheal tubulogenesis. Improved methods for studying the dynamics of the tracheal mesenchyme development are needed to investigate the cellular and molecular mechanisms during tracheal tubulogenesis. Here, we describe a detailed protocol for a systematic analysis of tracheal tube development to enable observing tracheal smooth muscle (SM) and cartilage ring formation. We describe immunostaining, confocal and stereomicroscopy imaging, and quantitative methods to study the process of tracheal SM and cartilage ring development, including SM cell alignment, polarization, and changes in cell shape as well as mesenchymal condensation. The technologies and approaches described here not only improve analysis of the patterning of the developing trachea but also help uncover the mechanisms underlying airway disease. This protocol also provides a useful technique to analyze cell organization, polarity, and nuclear shape in other organ systems.

It's a Bird, It's a Plane, It's a Vein: Jugular Vein Phlebectasia in a Pediatric Patient With Tracheomalacia

Jugular vein phlebectasia is seen in the first decade of life and carries a high chance of misdiagnosis as it can often be mistaken for other conditions observed in pediatric populations. High clinical suspicion along with radiological studies can help to confirm the diagnosis. Treatment is usually conservative, with surgery reserved for unique circumstances. This is the first case to be reported with concomitant tracheomalacia and a history of tracheoesophageal fistula repair in a pediatric patient with external jugular vein phlebectasia.

External airway splint placement for severe pediatric tracheobronchomalacia

OBJECTIVE

To present external airway splinting with bioabsorbable airway supportive devices (ASD) for severe, life-threatening cases of pediatric tracheomalacia (TM) or tracheobronchomalacia (TBM).

METHODS

A retrospective cohort was performed for 5 pediatric patients with severe TM or TBM who underwent ASD placement. Devices were designed and 3D-printed from a bioabsorbable material, polycaprolactone (PCL). Pre-operative planning included 3-dimensional airway modeling of tracheal collapse and tracheal suture placement using nonlinear finite element (FE) methods. Pre-operative modeling revealed that triads along the ASD open edges and center were the most effective suture locations for optimizing airway patency. Pediatric cardiothoracic surgery and otolaryngology applied the ASDs by suspending the trachea to the ASD with synchronous bronchoscopy. Respiratory needs were trended for all cases. Data from pediatric patients with tracheostomy and diagnosis of TM or TBM, but without ASD, were included for discussion.

RESULTS

Five patients (2 Females, 3 Males, ages 2-9 months at time of ASD) were included. Three patients were unable to wean from respiratory support after vascular ring division; all three weaned to room air post-ASD. Two patients received tracheostomies prior to ASD placement, but continued to experience apparent life-threatening events (ALTE) and required ventilation with supraphysiologic ventilator settings. One patient weaned respiratory support successfully after ASD placement. The last patient died post-ASD due to significant respiratory co-morbidity.

CONCLUSION

ASD can significantly benefit patients with severe, unrelenting tracheomalacia or tracheobronchomalacia. Proper multidisciplinary case deliberation and selection are key to success with ASD. Pre-operative airway modeling allows proper suture placement to optimally address the underlying airway collapse.

Isolated Tracheabronchomalacia Misdiagnosed for Years as Bronchial Asthma

Tracheomalacia (TM) is an abnormal collapse of the tracheal lumen, which often occurs when the cartilaginous part of the trachea has not developed. It is a rare condition but is seen often in infancy and childhood period. The incidence of primary airway malacia in children was estimated to be at least one in 2,100. It has a wide range of etiologies, and it is often localized but rarely generalized as in our case. It could be severe enough to indicate frequent admission and might expose the patient to multiple unnecessary medications. We are reporting a case with unusual primary tracheobronchomalacia (TBM) that was missed for several years with a huge burden on both families and healthcare providers. A five-year-old Saudi girl had multiple admissions to the intensive care unit with similar presentation each time, and she was misdiagnosed as having asthma exacerbation with an occasional chest infection. Bronchoscopy revealed the underlying condition, and the patient was kept on the minimal intervention of nasal continuous positive airway pressure (CPAP) and aggressive airway hydration therapy, all with the goal of improving the patient's outcome and reducing hospital admissions. We emphasize the importance of alerting physicians about malacia as an important cause of recurrent wheezy chest, which is one of the common asthma mimickers; in such cases, flexible bronchoscopy remains the gold standard diagnostic test, while the treatment remained supportive.

Anatomy and embryology of tracheo-esophageal fistula

Anomalies in tracheo-esophageal development result in a spectrum of congenital malformations ranging from, most commonly, esophageal atresia with or without trachea-esophageal fistula (EA+/-TEF) to esophageal web, duplication, stricture, tracheomalacia and tracheal agenesis. Despite the relative frequency of EA, however, the underlying etiology remains unknown and is likely due to a combination of genetic, epigenetic and environmental factors. In recent years, animal models have dramatically increased our understanding of the molecular and morphological processes involved in normal esophageal development during the key stages of anterior-posterior regionalization, dorsal-ventral patterning and morphogenic separation. Moreover, the use of animal models in conjunction with increasingly advanced techniques such as genomic sequencing, sophisticated live imaging studies and organoid models have more recently cast light on potential mechanisms involved in EA pathogenesis. This article aims to unravel some of the mysteries behind the anatomy and embryology of EA whilst providing insights into future directions for research.

Advances in Complex Congenital Tracheoesophageal Anomalies

Esophageal atresia with or without tracheoesophageal fistula and tracheobronchomalacia encompass 2 of the most common complex congenital intrathoracic anomalies. Tailoring interventions to address the constellation of problems present in each patient is essential. Due to advances in neonatology, anesthesia, pulmonary, gastroenterology, nutrition and surgery care for patients with complex congenital tracheoesophageal disorders has improved dramatically. Treatment strategies tailored to the individual patient needs are best implimented under the aegis of a comprehensive longitudinal multidisciplinary care team.

Paediatric tracheobronchomalacia: Incidence, patient characteristics, and predictors of surgical intervention

OBJECTIVES

Tracheobronchomalacia (TBM), a condition where an abnormality of the tracheal walls causes collapse during the respiratory cycle, is a common cause of airway obstruction in childhood. TBM can present with a large spectrum of disease severity and underlying pathologies that may be managed medically and surgically, and it is not always clear which patients would most benefit from surgical intervention. We aim to describe the incidence, patient characteristics, and predictors of surgical intervention in a large cohort of paediatric patients.

METHODS

We performed a retrospective review of all children diagnosed with TBM to a paediatric Otolaryngology unit in the west of Scotland between 2010 and 2020. Odds ratios for clinical predictors of surgery were calculated using logistic regression with uni- and multivariate analysis.

RESULTS

249 patients were identified of which 219 proceeded to data collection. Primary malacia was noted in 161 (73.5%) and secondary in 58 (26.5%). Causes of secondary malacia included compression by the innominate artery (11%) and vascular rings (7.8%). Surgical interventions were performed in 28 patients (12.8%) including division of vascular ring, aortopexy, and surgical tracheostomy. Multivariate analysis showed secondary TBM, acute life-threatening events, and difficulty weaning from mechanical ventilation were independent risk factors for surgical intervention.

CONCLUSIONS

TBM can present with a myriad of airway symptoms and is frequently associated with other airway and mediastinal pathologies necessitating multiple interventions. Children aged <1 year present with a more severe form of the disease and the presence of particular independent risk factors may indicate a need for surgical intervention.

Thoracoscopic posterior tracheopexy during primary esophageal atresia repair ameliorate tracheomalacia in neonates: a single-center retrospective comparative cohort study

BACKGROUND

Esophageal atresia (EA) is often associated with tracheomalacia (TM). The severity of TM symptoms varies widely, with serious cases requiring prolonged respiratory support and surgical treatment. Although we performed thoracoscopic posterior tracheopexy (TPT) during primary EA repair to prevent or reduce the symptoms of TM, few studies have investigated the safety and effectiveness of TPT during primary EA repair. Therefore, this study aimed to evaluate the safety and efficacy of TPT in neonates.

METHODS

We retrospectively reviewed the records of all patients diagnosed with TM who underwent primary thoracoscopic EA repair between 2013 and 2020 at the Nagoya University Hospital. Patients were divided into two groups: TPT (TPT group) and without TPT (control group). TPT has been performed in all patients with EA complicated by TM since 2020. We compared patient backgrounds, surgical outcomes, postoperative complications, and treatment efficacy.

RESULTS

Of the 22 patients reviewed, eight were in the TPT group and 14 were in the control group. There were no statistically significant differences in the surgical outcomes between the groups (operation time: p = 0.31; blood loss: p = 0.83; time to extubation: p = 0.30; time to start enteral feeding: p = 0.19; time to start oral feeding: p = 0.43). Conversion to open thoracotomy was not performed in any case. The median operative time required for posterior tracheopexy was 10 (8-15) min. There were no statistically significant differences in postoperative complications between the groups (chylothorax: p = 0.36; leakage: p = 1.00; stricture: p = 0.53). The respiratory dependence rate 30 days postoperative (2 [25%] vs. 11 [79%], p = 0.03) and the ratio of the lateral and anterior-posterior diameter of the trachea (LAR) were significantly lower in the TPT group (1.83 [1.66-2.78] vs. 3.59 [1.80-7.70], p = 0.01).

CONCLUSIONS

TPT during primary EA repair for treatment of TM significantly lowered respiratory dependence rate at 30 days postoperative without increasing the risk of postoperative complications. This study suggested that TPT could improve TM associated with EA.

Histological and structural effects of biodegradable polydioxanone stents in the rabbit trachea

OBJECTIVES

The aim of this study was to evaluate the potential biologic effects caused by successive placement of biodegradable polydioxanone (PDO) stents in the rabbit trachea. PDO stents could eventually induce a fibroproliferative reaction in the submucosa that could be beneficial in the treatment of malacia due to an increase in its consistency without impairing the tracheal lumen.

METHODS

Sixteen adult NZ rabbits were distributed into 3 groups with different survival times according to the number of stents placed: One stent (14 weeks), 2 stents (28 w.), and 3 stents (42 w.). Stent insertion was performed endoscopically in the cervical trachea of the animal. Histopathological studies included Masson's trichrome staining for submucosal fibrosis and Safranin O to assess structural integrity of cartilage. Potential inflammatory changes were analysed by means of immunohistochemistry determining the number of CD45 positive cells.

RESULTS

Stent placement was successful in every case. Histological studies did not show a statistically significant increase in tracheal wall collagen area and cartilage structure was not modified in those rabbits with one or more PDO stents inserted compared to non-stented tracheal sections. Furthermore, no statistically significant changes in the number of CD45+ cells were observed in stented tracheal segments compared to normal tracheal tissues.

CONCLUSIONS

According to our data, successive PDO stenting caused mild inflammatory changes in the tracheal wall, no increase in the collagen matrix, and the cartilaginous support was not modified during a long follow-up period (up to 42 weeks). These findings suggest that they may be safe and show good biocompatibility in the long-term.

Poor correlation between airway fluoroscopy and rigid bronchoscopic evaluation in paediatric tracheomalacia

INTRODUCTION

Tracheomalacia is a common congenital condition causing stridor in young children. However, the evaluation of these children remains poorly standardised across institutions.

METHODS

We conducted a retrospective review of all children undergoing an elective laryngotracheobronchoscopy at a single tertiary paediatric institution between March 2010 and December 2018. Emergency bronchoscopies and children with tracheostomies were excluded. 1163 children undergoing an elective bronchoscopy were included in this study, and 545 children also had an airway fluoroscopy.

RESULTS

The median age at bronchoscopy was 17 months, and the majority of children were male. Tracheomalacia was diagnosed in 21.6% of children at bronchoscopy, of these 48.5% had tracheomalacia diagnosed on a previous airway fluoroscopy. Overall, airway fluoroscopy had a low sensitivity (62.3%) and a low specificity (67.5%) for diagnosis of tracheomalacia when compared with bronchoscopy. Increasing severity of tracheomalacia on airway screen significantly predicted a diagnosis of tracheomalacia on bronchoscopy.

CONCLUSIONS

Airway fluoroscopy has a low sensitivity and specificity in diagnosis of tracheomalacia and should be used judiciously rather than as a screening tool for children with stridor. However, this imaging technique may be beneficial in investigating children with severe symptoms who have had other conditions such as laryngomalacia excluded.

Association of childhood tracheomalacia with bronchiectasis: a case-control study

OBJECTIVE

Children with tracheomalacia can develop chronic lower airway infection and neutrophilic inflammation. It is plausible children with tracheomalacia are at increased risk of developing bronchiectasis. We hypothesised that compared with controls, tracheomalacia in children is associated with bronchiectasis.

DESIGN

Single-centre, case-control study.

SETTING AND PATIENTS

45 children with chest high-resolution CT (c-HRCT) confirmed bronchiectasis (cases) and enrolled in the Australian Bronchiectasis Registry were selected randomly from Queensland, and 90 unmatched children without chronic respiratory symptoms or radiographic evidence of bronchiectasis (disease controls). Cases and controls had flexible bronchoscopy performed for clinical reasons within 4 weeks of their c-HRCT.

INTERVENTIONS

The bronchoscopy videos were reviewed in a blinded manner for: (a) any tracheomalacia (any shape deformity of the trachea at end-expiration) and (b) tracheomalacia defined by the European Respiratory Society (ERS) statement (>50% expiratory reduction in the cross-sectional luminal area).

MAIN OUTCOME MEASURES AND RESULTS

Cases were younger (median age=2.6 years, IQR 1.5-4.1) than controls (7.8 years, IQR 3.4-12.8), but well-balanced for sex (56% and 52% male, respectively). Using multivariable analysis (adjusted for age), the presence of any tracheomalacia was significantly associated with bronchiectasis (adjusted OR (OR_adj)=13.2, 95% CI 3.2 to 55), while that for ERS-defined tracheomalacia further increased this risk (OR_adj=24.4, 95% CI 3.4 to infinity).

CONCLUSION

Bronchoscopic-defined tracheomalacia is associated with childhood bronchiectasis. While causality cannot be inferred, children with tracheomalacia should be monitored for chronic (>4 weeks) wet cough, the most common symptom of bronchiectasis, which if present should be treated and then investigated if the cough persists or is recurrent.

Personalized 3D-Printed Bioresorbable Airway External Splint for Tracheomalacia Combined With Congenital Heart Disease

Severe tracheomalacia (TM) patients with respiratory symptoms need surgical intervention, including aortopexy, internal stents or external splint. While some patients continue to have respiratory symptoms after tracheal relief, and there is no evidence to support any one surgery therapy over another. Here we introduce a clinical safety and efficacy of the three-dimensional (3D)-printed bioresorbable airway external splints in treating congenital heart disease (CHD) patients with severe TM. From May 2019 to September 2020, nine patients with severe TM were enrolled. The median age was 5 months (range, 3–25 months), and the median weight was 7.5 kg (range, 3–15 kg). All patients had wheezing, and two patients were assisted by machine ventilation (MV) preoperatively. The median length of TM was 1.5 cm (range, 1.0–3.0 cm). All patients underwent suspension of a “C”-shaped lumen airway external splint, which were designed in SOLIDWORKS and made of polycaprolactone (PCL). The airway external splint could provided effective support for at least 6 months and was completely degraded into carbon dioxide and water within 2–3 years. The median time of postoperative machine assisted ventilation was 23.7 h (range, 3.3–223.4 h), and the median time of ICU stay was 9 days (range, 4–25 days). The median follow-up time was 18 months (range, 12–24 months). Respiratory symptoms were all relieved, and no external splint-associated complications occurred. The 3D computed tomography reconstruction showed no airway stenosis. Personalized 3D-printed bioresorbable airway external splint can not only limit external compression and prevent airway collapse but also ensure the growth potential of the airway, which is a safe, reliable and effective treatment for CHD with TM.

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.

Recurrent Croup

Croup refers to airway inflammation and edema leading to obstruction of the larynx, trachea, and bronchi. Croup is the most common cause of acute airway obstruction in young children. It is characterized by the onset of low-grade fever, barky cough, stridor, hoarseness, and respiratory distress. Croup is typically caused by a viral infection (viral croup) but can occur suddenly without a viral prodrome (spasmodic croup). Recurrent croup is defined as two or more episodes per year. Recurrent croup should be considered a symptom of an underlying structural or inflammatory airway abnormality and should prompt a work-up for the underlying cause.

A term neonate with cyanosis with crying

Congenital short trachea can be associated with bronchial compression with associated symptoms of apnoea, cyanosis, increased work of breathing, and/or respiratory failure in infancy. Operative intervention should be considered in symptomatic cases. https://bit.ly/3gM6Vv9.

Surgical management of long-segment congenital tracheal stenosis with tracheobronchial malacia

OBJECTIVES

Slide tracheoplasty has become the mainstream treatment for long-segment congenital tracheal stenosis (LSCTS). However, technical improvements are still needed to improve the clinical outcomes of patients exhibiting LSCTS with tracheobronchial malacia.

METHODS

LSCTS patients who underwent tracheoplasty from January 2010 to December 2020 were reviewed. According to the time of surgical technique modifications for reconstructing a supportive carina, the patients were divided into 2 groups: group A (2010-2018) and group B (2019-2020). We identified a well-balanced cohort matched by propensity score to evaluate the differences in surgical outcomes between the 2 groups.

RESULTS

There were no significant differences between group A and group B in any of the 8 characteristics before and after propensity score matching. In the propensity score-matched cohort, the number of patients who accepted anterior carina tracheopexy (75/77 vs 4/77, P < 0.001) and in situ pericardium insertion (75/77 vs 14/77, P < 0.001) in group B was significantly greater than that in group A. The mechanical ventilation time [48.3 (interquartile range: 29.6, 116.3) h vs 73.3 (interquartile range: 47.9, 111.6) h, P = 0.009] and cumulative mortality (P = 0.023) were significantly lower in Group B than Group A.

CONCLUSIONS

Reconstructing a supportive, stable carina of the neotrachea and tracheobronchopexy are helpful to improve the outcomes of slide tracheoplasty.

An imaging study on tracheomalacia in infants with esophageal atresia: the degree of tracheal compression by the brachiocephalic artery is a good indicator for therapeutic intervention

PURPOSE

Tracheomalacia (TM) is a frequent complication after esophageal atresia (EA) repair. This study aimed to review patients who underwent aortopexy for TM after EA repair and to compare their imaging features.

METHODS

The patients who underwent thoracoscopic EA repair and contrast-enhanced computed tomography (CECT) at our hospital between 2013 and 2020 were retrospectively reviewed. The ratio of the lateral and anterior-posterior diameter of the trachea (LAR) where the brachiocephalic artery (BCA) crosses the trachea was defined. The LAR of the patients who underwent CECT for asymptomatic pulmonary disease was set as a normal reference. The Z-score of each LAR was calculated and compared between the patients that did or did not undergo aortopexy.

RESULTS

A total of 51 patients represented the controls, 5 patients underwent aortopexy, and 12 patients were discharged without surgery. The mean LARs in the patients who underwent aortopexy, did not undergo aortopexy, and controls were 3.54, 1.54, and 1.15, respectively. The mean Z-score of the aortopexy group was 21.2. After successful aortopexy, each patient's LAR decreased to < 1.5.

CONCLUSION

Aortopexy was preferred if the trachea was compressed by the BCA. The LAR is a useful indicator for predicting the therapeutic effect of aortopexy.

When is asthma not guilty?

Asthma is a common childhood condition. Its prevalence in Saudi Arabia is high, increasing, and could exceed 20% at the current trajectory. Asthma is a syndrome with different clinical presentations and phenotypes. Many conditions are often misdiagnosed as asthma because they share the same symptoms, particularly coughing and shortness of breath; physical findings, such as wheezing; radiological findings, such as hyperinflation on chest X-ray; or even responses to asthma therapies, as in some patients with bronchiolitis. When treating the younger age group (>5 years old), there should be a high degree of suspicion of alternative causes when evaluating patients presenting with clinical features suggestive of asthma or patients who do not respond well to asthma therapies. This study will highlight common conditions that may mimic asthma and, as a result of incorrect treatment, unnecessarily expose patients to steroids and other therapies for extended periods. Furthermore, we seek to alert healthcare providers to common symptoms and signs that suggest a cause other than asthma and suggest when to refer the patient to subspecialists.

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.

Determining normal values for lower trachea and bronchi size in children by computed tomography (CT)

BACKGROUND

Normative data for central airway dimensions are a prerequisite to objectively assess large airway pathologies. Studies with computed tomography (CT) measurements of normal trachea and bronchi size in children are scarce.

OBJECTIVE

The purpose of this study is to establish normal values of central airway dimensions in children by CT.

METHODS

The study included chest CT studies from children aged 0-18 years. Any condition that predisposed the patient to have an abnormal tracheal or bronchial size was excluded. Airway diameters and cross-sectional area (CSA) were measured using double oblique reconstructions at five levels: proximal trachea, mid-trachea, distal trachea, right main bronchus, and left main bronchus.

RESULTS

The inclusion criteria were met by 110 subjects (mean age, 10.8 years; SD, 5.2 years). Various regression models that considered the relationship between patient demographics and anteroposterior (AP) diameter, transverse diameter, and CSA at each of the five levels were assessed. R² was utilized to select the best model. Multiple formulae (using patient age) were developed to calculate expected normal dimensions for five levels in the central airways on the natural log scale. Finally, z-scores were obtained for central airway dimensions at these five levels.

CONCLUSION

Normative data in pediatric central airways are crucial to identify large airway pathologies. We propose using the formulae devised in our study to calculate the predicted dimensions of central airways and their z-scores in pediatric patients. Normative data from our study will aid in objective quantification of central airways, increase clinician confidence, and provide appropriate patient care.

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.

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.

Airway Clearance in Tracheomalacia

Airway clearance is an essential part of airway maintenance to ensure the airway lumen is protected against particulate and infectious insults. The mechanisms involved in airway clearance include intrinsic structural and cellular components that can be impaired or inhibited through developmental defects and surgical interventions. Tracheomalacia is a developmental defect of the airway that can contribute to the mechanical failure to clear the airway. This chapter will review the mechanisms of airway clearance and the processes that can impair this vital process.

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.

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.

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.

Primary Posterior Tracheopexy in Esophageal Atresia Decreases Respiratory Tract Infections

Background: Esophageal atresia (EA) is often accompanied by tracheomalacia (TM). TM can lead to severe respiratory complaints requiring invasive treatment. This study aims to evaluate if thoracoscopic primary posterior tracheopexy (PPT) can prevent the potential sequelae of TM in patients with EA. Methods: A cohort study including all consecutive EA patients treated between 2014 and July 2019 at the Wilhelmina Children's Hospital was conducted. Two groups were distinguished: (group 1) all EA patients born between January 2014 and December 2016 and (group 2) all EA patients born between January 2017 and July 2019, after introduction of PPT. In the latter group, PPT was performed in EA patients with moderate (33-66%) or severe (67-100%) tracheomalacia, seen during preoperative bronchoscopy. Group differences were assessed using the Fisher's exact test for bivariate variables and the Mann-Whitney U-test for continuous variables. Results: A total of 64 patients were included in this study (28 patients in group 1; 36 patients in group 2). In group 2, PPT was performed in 14 patients. Respiratory tract infections (RTIs) requiring antibiotics within the first year of life occurred significantly less in group 2 (61 vs. 25%, p = 0.004). Brief resolved unexplained events (BRUEs) seemed to diminish in group 2 compared to group 1 (39 vs. 19%, p = 0.09). Conclusion: Thoracoscopic primary posterior tracheopexy decreases the number of respiratory tract infections in EA patients. The clinical impact of reducing RTIs combined with the minimal additional operating time and safety of PPT outweighs the risk of overtreatment.

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.

Disruption of a hedgehog-foxf1-rspo2 signaling axis leads to tracheomalacia and a loss of sox9+ tracheal chondrocytes

Congenital tracheomalacia, resulting from incomplete tracheal cartilage development, is a relatively common birth defect that severely impairs breathing in neonates. Mutations in the Hedgehog (HH) pathway and downstream Gli transcription factors are associated with tracheomalacia in patients and mouse models; however, the underlying molecular mechanisms are unclear. Using multiple HH/Gli mouse mutants including one that mimics Pallister-Hall Syndrome, we show that excessive Gli repressor activity prevents specification of tracheal chondrocytes. Lineage tracing experiments show that Sox9+ chondrocytes arise from HH-responsive splanchnic mesoderm in the fetal foregut that expresses the transcription factor Foxf1. Disrupted HH/Gli signaling results in 1) loss of Foxf1 which in turn is required to support Sox9+ chondrocyte progenitors and 2) a dramatic reduction in Rspo2, a secreted ligand that potentiates Wnt signaling known to be required for chondrogenesis. These results reveal a HH-Foxf1-Rspo2 signaling axis that governs tracheal cartilage development and informs the etiology of tracheomalacia.

Endoscopic management of pediatric extubation failure in the intensive care unit

OBJECTIVES

This study investigated the endoscopic findings associated with pediatric extubation failure (EF) and evaluated the prognosis of endoscopic procedures.

METHODS

We retrospectively reviewed the data of children with EF in the intensive care unit from January 1, 2013 to December 31, 2019. Fifty-one children receiving endoscopic examination were enrolled in this study. EF was defined as the need for reintubation within 72 h of the first attempted extubation.

RESULTS

Thirty-three children (65%) were successfully extubated after endoscopic procedures, and 18 children (35%) failed in extubation. There was a higher percentage of children transferred from other hospitals with intubation in the failure group (56% vs 12%, p = 0.002). Subglottic stenosis (SGS) (35%) and laryngeal and tracheal granulation (33%) were two of the most common findings. Fourteen patients (82%) with granulation were successfully extubated. Two children in the failure group were diagnosed with mitochondrial myopathies (chrM:3243) and congenital myasthenic syndrome (CHAT). The success rate in cases of SGS reached 83% (15/18). Five patients diagnosed with laryngomalacia and another 3 patients with tracheomalacia failed extubation after supraglottoplasty and needed a temporary tracheostomy.

CONCLUSION

Granulation and subglottic stenosis were the leading causes of extubation failure. Patients transferred with intubation might have a poor prognosis after endoscopic procedures. Neuromuscular and metabolic disorders could be a hidden reason for extubation failure.

When to consider a posterolateral descending aortopexy in addition to a posterior tracheopexy for the surgical treatment of symptomatic tracheobronchomalacia

PURPOSES

The descending thoracic aorta typically crosses posterior to the left mainstem bronchus (LMSB). We sought to evaluate patient factors that may lead one to consider a posterolateral descending thoracic aortopexy (PLDA) in addition to a posterior tracheopexy (PT) in the surgical treatment of symptomatic tracheobronchomalacia (TBM) that involves the LMSB.

METHODS

Retrospective review of patients who underwent PT with or without PLDA between 2012 and 2017. Severity and extent of TBM were assessed using dynamic tracheobronchoscopy. Aortic positioning compared to the anterior border of the spine (ABS) at the level of the left mainstem bronchus was identified on computed tomography (CT). Factors associated with performing a PLDA were evaluated with logistic regression.

RESULTS

Of 188 patients who underwent a PT, 70 (37%) also had a PLDA performed. On multivariate analysis, >50% LMSB compression on bronchoscopy (OR 8.06, p < 0.001), >50% of the aortic diameter anterior to the ABS (OR 2.06, p = 0.05), and more recent year of surgery (OR 1.61, p = 0.003) were associated with performing a PLDA.

CONCLUSION

When performing a PT, a PLDA should be considered for patients who have >50% LMSB compression on dynamic bronchoscopy, and in those with a descending thoracic aorta located >50% anterior to the ABS.

LEVEL OF EVIDENCE

III TYPE OF STUDY: Retrospective comparative study.

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.

The clinical safety and efficacy of flexible bronchoscopy in a neonatal intensive care unit

Flexible bronchoscopy (FB), developed in the 1960s, is widely used in the clinical practice of pediatrics and has demonstrated fundamental value in clinical diagnoses and treatment. However, as an invasive procedure, the use of FB is limited due to concerns regarding the tolerance of the procedure and the possible complications in neonatal units. Thus, the present study aimed to investigate the clinical safety and efficacy of flexible bronchoscopy (FB) in a neonatal intensive care unit (NICU). Neonates (n=54) who received FB in the NICU of Shanghai Children's Hospital between January 2012 and December 2016 were enrolled as the experimental group and another 54 neonates who required nebulization and tracheal secretion suction treatments were the control group. Indicators including blood gas, complete blood count, C-reactive protein (CRP), X-ray, patient breathing rate, temperature and blood pressure were monitored prior to and following the procedure. No significant differences in sex, gestational age, birth weight or postnatal age were observed between the experimental group and the control group (P>0.05). Among the 54 FB patients, several cases with side effect were identified, including 18 (33.3%) with respiratory tract stenosis, nine (16.7%) with malacia and stenosis and six (11.1%) with esophagotracheal fistula. Among the 54 members of the control group, 44 neonates (81.4%) were discharged with improved condition, five (9.3%) succumbed and five patients (9.3%) abandoned the treatment and left the hospital. Bronchoalveolar lavage demonstrated consistent results with respiratory secretion culture or tracheal tube culture. In comparison between the experimental and the control groups, no significant difference in pH, partial pressure of carbon dioxide (PCO₂), partial pressure of oxygen (PO₂) and HCO₃ ^- was observed, while there were no statistical differences in the values of pH, PCO₂ and HCO₃ ^- (P>0.05). However, PO₂ was significantly increased, and CRP was significantly reduced, following FB procedure compared with prior to FB (P<0.05). No pneumothorax, shock, other severe complications, fever or diffused pneumonia were observed during or after FB. The data from the present study demonstrated that FB is a safe and effective strategy for the diagnosis and differentiation of neonatal respiratory diseases in NICU.