Helical multi-detector CT scan as a tool for diagnosing tracheomalacia in children

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.

Acquired tracheomalacia due to SARS-CoV-2 pneumonia

INTRODUCTION

Several studies mentioned parenchymal findings after SARS-CoV-2 pneumonia, but few studies have mentioned alterations in the airways. The aim of this study was to estimate the prevalence of tracheomalacia and to analyse the clinical characteristics in a cohort of patients with SARS-CoV-2.

METHODS

The study population consisted of all patients with SARS-CoV-2 admitted a hospital serving a population of 500 000 inhabitants. Patients were visited between 2 and 6 months after hospital discharge. In this visit, all patients were subjected to an exhaustive clinical questionnaire and underwent clinical examination, pulmonary function tests and chest CT.

RESULTS

From February 2020 to August 2021, 1920 patients were included in the cohort and tracheomalacia was observed in 15 (0.8%) on expiratory HRCT imaging. All patients with tracheomalacia also presented ground glass opacities in the CT scan and 12 patients had airway sequelae.

CONCLUSIONS

Tracheomalacia is an exceptional sequela of SARS-CoV-2 survivors.

Bronchopulmonary dysplasia from chest radiographs to magnetic resonance imaging and computed tomography: adding value

Bronchopulmonary dysplasia (BPD) is a common long-term complication of preterm birth. The chest radiograph appearance and survivability have evolved since the first description of BPD in 1967 because of improved ventilation and clinical strategies and the introduction of surfactant in the early 1990s. Contemporary imaging care is evolving with the recognition that comorbidities of tracheobronchomalacia and pulmonary hypertension have a great influence on outcomes and can be noninvasively evaluated with CT and MRI techniques, which provide a detailed evaluation of the lungs, trachea and to a lesser degree the heart. However, echocardiography remains the primary modality to evaluate and screen for pulmonary hypertension. This review is intended to highlight the important findings that chest radiograph, CT and MRI can contribute to precision diagnosis, phenotyping and prognosis resulting in optimal management and therapeutics.

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

Vascular and pulmonary comorbidities in children with congenital EA/TEF

BACKGROUND

Esophageal atresia with tracheoesophageal fistula (EA/TEF) is associated with many congenital and vascular malformations; however, reports utilizing computed tomography (CT) and computed tomography angiography (CTA) are limited. The objective of this study is to review CT scans of the chest from patients with EA/TEF and report their pulmonary and vascular findings.

METHODS

We completed a retrospective chart review of children with congenital EA/TEF evaluated in the aerodigestive clinic at Children's Hospital Colorado. Results of the most recent CTA or CT of the chest were investigated. Demographics, medical conditions, and bronchoscopy findings were also recorded. The ratio of tracheal lumen area between inspiratory and expiratory CTA images was measured.

RESULTS

Of the patients with congenital EA/TEF seen in the program, 47 patients had a chest CT available for review. Eight patients (17%) had bronchiectasis. Of the contrast CT scans, 15 (58%) had a vascular abnormality and 16 (62%) demonstrated tracheal compression (38% at the level of the innominate artery, 35% from other structures). Nineteen of the CTAs had volumetric expiratory images of the trachea to evaluate tracheomalacia. The mean expiratory:inspiratory area was 0.57 (SD ± 0.23) at the level of the innominate.

CONCLUSION

Patients with EA/TEF frequently have vascular abnormalities that may alter airway mechanics as well as pulmonary comorbidities that may affect long-term management. For patients experiencing persistent respiratory symptoms, CTA of the chest should be considered adjunct to bronchoscopy to help with medical and surgical management of these children.

Large airway diseases in pediatrics: a pictorial essay

“Large airway diseases” is being used as an all-encompassing phrase to describe a broad spectrum of pathological entities, which involves the trachea, main, lobar, and segmental bronchi of up to 3 mm diameter. Imaging modalities such as radiography, computed tomography, and magnetic resonance imaging contribute to the identification and diagnosis of each entity. Knowledge of clinical information, normal cross-sectional anatomy, and imaging characteristics of large airway diseases is necessary for appropriate radiologic evaluation. This review provides information about congenital and acquired diseases of the large airways in the pediatric population.

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.

ERS statement on tracheomalacia and bronchomalacia in children

Tracheomalacia and tracheobronchomalacia may be primary abnormalities of the large airways or associated with a wide variety of congenital and acquired conditions. The evidence on diagnosis, classification and management is scant. There is no universally accepted classification of severity. Clinical presentation includes early-onset stridor or fixed wheeze, recurrent infections, brassy cough and even near-death attacks, depending on the site and severity of the lesion. Diagnosis is usually made by flexible bronchoscopy in a free-breathing child but may also be shown by other dynamic imaging techniques such as low-contrast volume bronchography, computed tomography or magnetic resonance imaging. Lung function testing can provide supportive evidence but is not diagnostic. Management may be medical or surgical, depending on the nature and severity of the lesions, but the evidence base for any therapy is limited. While medical options that include bronchodilators, anti-muscarinic agents, mucolytics and antibiotics (as well as treatment of comorbidities and associated conditions) are used, there is currently little evidence for benefit. Chest physiotherapy is commonly prescribed, but the evidence base is poor. When symptoms are severe, surgical options include aortopexy or posterior tracheopexy, tracheal resection of short affected segments, internal stents and external airway splinting. If respiratory support is needed, continuous positive airway pressure is the most commonly used modality either via a face mask or tracheostomy. Parents of children with tracheobronchomalacia report diagnostic delays and anxieties about how to manage their child's condition, and want more information. There is a need for more research to establish an evidence base for malacia. This European Respiratory Society statement provides a review of the current literature to inform future study.