Airway Fluoroscopy Research Articles

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

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

Laryngotracheal anomalies and airway fluoroscopy in infants

ObjectivesThe role of airway fluoroscopy in the diagnosis of laryngotracheal anomalies in infants is controversial. We aimed to (i) compare airway fluoroscopic characteristics with endoscopic findings in infants presenting for evaluation of upper airway obstruction and (ii) assess the as low as is reasonably achievable (ALARA) status for airway fluoroscopy as an initial diagnostic test in suspected laryngotracheal anomalies. Materials and methodsWe performed a retrospective review of children who underwent fluoroscopy and endoscopic evaluation of the airway in the operating room for suspected laryngotracheal anatomic abnormalities. Thirty-four infants who underwent both procedures at a tertiary level university-based children's hospital from January 1, 2008 to December 1, 2013 were included. Infants with suspected foreign bodies or an existing tracheostomy were excluded. Intraoperative findings from endoscopy and radiologic interpretation from fluoroscopy were compared using standard tools for validation of a diagnostic test. These metrics were compared with historic data that suggested good correlation between radiologic and endoscopic findings in older children. ResultsThe median age was 3.6 months (range 1–8 months). The sensitivity of airway fluoroscopy for determining laryngotracheal pathology was 18%. Specificity, positive predictive value and negative predictive value were 83%, 67% and 35%, respectively. Although each fluoroscopic exposure was optimized for pediatric patients, the median cumulative exposure to ionizing radiation was 19 mR (range 10–34 mR). ConclusionsAirway fluoroscopy yields metrics that are overall poor to be considered a valid and accurate universal radiologic diagnostic test in infants evaluated for laryngotracheal pathology. The cumulative exposure to ionizing radiation from use of a fluoroscope cannot be justified by the sensitivity of the test and may not conform to ALARA standards for imaging in this population.

Hypopharyngeal, Supraglottic and Subglottic Stenosis after 1 Week Intubation

Hypopharyngeal, Supraglottic and Subglottic Stenosis after 1 Week Intubation

Superior herniation of the mediastinum presenting as an anterior neck mass on straining

We report an infant with an anterior neck mass present only on straining. Airway fluoroscopy revealed this to be due to superior mediastinal herniation. Neck masses apparent only during Valsalva maneuver are rare and awareness of the differential diagnosis is important to avoid unnecessary investigation or surgery.

Diagnostic value of various investigations in children with suspected foreign body aspiration

Foreign body aspiration is a serious condition during childhood that requires prompt management to avoid complications and irreversible lung injury. Rigid bronchoscopy under general anaesthesia is the procedure of choice for removal of aspirated foreign bodies, but it can be associated with serious complications. The positive diagnosis can sometimes be challenging except in the case of radiopaque or obstructive foreign bodies, due to the low sensitivity and specificity of clinical history and physical examination. The aim of this review is to evaluate the various investigations in children with suspected foreign body aspiration, in order to reduce the negative rigid bronchoscopy rate. Review of the literature based on Medline data between 1980 and 2010. Chest radiography during inspiration and expiration, often performed as the first-line radiographic investigation, has a low sensitivity and specificity. In the absence of a radiopaque foreign body, obstructive emphysema is the most specific radiographic sign. Airway fluoroscopy can complete chest radiography when radiographic signs are nonspecific. Flexible bronchoscopy is the most sensitive and most specific examination, but is not always available, as it must be performed in the operating room or with resuscitation equipment at hand. This procedure should be performed when foreign body aspiration is suspected in the absence of typical clinical and radiological signs. It can decrease the number of negative rigid bronchoscopies. Several studies suggest that chest CT is also a very sensitive examination in this indication. The sensitivity and specificity of chest CT for the diagnosis of bronchial foreign body must be validated by a prospective study. A national multicentre study is currently underway to determine whether CT can replace flexible bronchoscopy when the diagnosis of bronchial foreign body is uncertain.

A comparison of fluoroscopic airway screening with flexible bronchoscopy for diagnosing tracheomalacia

Flexible bronchoscopy (FB) is the gold standard method of diagnosing tracheomalacia but it is not always feasible in settings with limited resources. Fluoroscopy is sometimes performed as an alternative diagnostic tool but there are no prospective studies that have evaluated the diagnostic accuracy of airway fluoroscopy for tracheomalacia using a-priori definitions. We determined the sensitivity, specificity, and likelihood predictive ratio of airway fluoroscopy compared with FB in children suspected of having an airway abnormality. Airway fluoroscopic examination was undertaken within 2-weeks of a FB in children aged <18-years and reported by a pediatric radiologist blinded to FB data. Fluoroscopic and FB methods and diagnostic criteria were standardized and defined a-priori. Tracheomalacia diagnosed by FB were independently scored (mild, moderate, severe) by 2 pulmonologists in a blinded manner. In 22 children (median age 33 months, range 1-187) evaluated for airway abnormality, tracheomalacia was found in 21 children at bronchoscopy. Of these, fluoroscopy detected tracheomalacia in five children. Airway fluoroscopy was poorly sensitive (23.8%) but highly specific (100%), positive likelihood ratio was 8.6. However, in moderate-severe tracheomalacia, the sensitivity improved to 57.1% but the specificity reduced (93.3%). The agreement between bronchoscopists for tracheomalacia severity was excellent, weighted kappa 0.74 (95% CI 0.77, 0.98). Airway fluoroscopy cannot replace FB which remains the tool for definitively diagnosing airway malacia. However, in absence of other modalities for diagnosis fluoroscopy should be considered in the setting of persistent respiratory symptoms compatible with the clinical picture of tracheomalacia.

Evaluation of the effectiveness of airway fluoroscopy in diagnosing patients with laryngomalacia

To re-evaluate the usefulness of airway fluoroscopy (AF) in diagnosing laryngomalacia and to determine the effectiveness of AF in diagnosing laryngomalacia depending on the specific lesion. Retrospective chart review. Patients from 0 to 12 months of age who presented with stridor were evaluated. Those who underwent AF and flexible fiberoptic laryngoscopy (FFL) and/or direct laryngoscopy (DL) were included in the study. The diagnosis made through AF, FFL, and/or DL were recorded with those considered definitive made through FFL and/or DL. The sensitivity, specificity, positive predictive value, and negative predictive value of AF compared to FFL and DL were calculated. The sensitivity, specificity, positive predictive value, and negative predictive value of AF with regard to specific sites of laryngeal collapse were calculated. AF showed an inconsistent sensitivity, specificity, and positive and negative predictive value compared to FFL and DL with regard to specific lesions. AF had an overall sensitivity of 35%, specificity of 67%, positive predictive value of 78%, and negative predictive value of 23% when compared to FFL in diagnosing laryngomalacia. When compared to DL, AF had an overall sensitivity of 44%, specificity of 60%, positive predictive value of 67%, and negative predictive value of 38% when diagnosing laryngomalacia. AF is a commonly used modality in the diagnostic workup of a patient with stridor. The effectiveness of AF is limited when compared to endoscopy when used for the evaluation of laryngomalacia.

Congenital subglottic cyst in a term neonate

A full-term infant born via vaginal delivery developed inspiratory stridor shortly after birth. Routine resuscitation was performed at delivery without the need for intubation. He received supplemental oxygen for 1...

The Role of Airway Fluoroscopy in the Evaluation of Children With Stridor

To determine the sensitivity and specificity of airway fluoroscopy in the diagnosis of pediatric laryngotracheal abnormalities. Retrospective chart review. Tertiary care children's hospital. Thirty-nine children, with a mean age of 18 months at the time of evaluation, were evaluated for stridor. Diagnoses made by airway fluoroscopy and endoscopy. The medical records of patients who had undergone both airway fluoroscopy and airway endoscopy for the evaluation of stridor over a 5-year period were reviewed. The sensitivity, specificity, and positive and negative predictive values of airway fluoroscopy in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis at any level, and airway mass lesions were determined using endoscopic evaluation as the "gold standard." Twenty-three of 39 patients (59%) received a different diagnosis by airway endoscopy than by airway fluoroscopy. The sensitivity of airway fluoroscopy in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis, and an airway mass was 27%, 20%, 69%, and 43%, respectively. The specificity for the same diagnoses was 100%, 94%, 100%, and 100%, respectively. Airway fluoroscopy appears to be reliable in the diagnosis of laryngomalacia, tracheomalacia, airway stenosis, and airway masses because of its high specificity. However, its sensitivity in detecting these common causes of stridor is poor. Negative fluoroscopic study results require further diagnostic evaluation if the clinical indication exists; therefore, the value of fluoroscopy as a screening tool remains uncertain.

Multimodality Imaging of Tracheobronchial Disorders in Children

The trachea and bronchial airways in children are subject to compromise by a number of extrinsic and intrinsic conditions, including congenital, inflammatory, infectious, traumatic, and neoplastic processes. Stridor, wheezing, and respiratory distress are the most common indications for imaging of the airway in children. Frontal and lateral chest and/or neck radiography constitute the initial investigations of choice in most cases. Options for additional imaging include airway fluoroscopy, contrast esophagography, computed tomography (CT), and magnetic resonance (MR) imaging. Advanced imaging techniques such as dynamic airway CT, CT angiography, MR angiography, and cine MR imaging are valuable for providing relevant vascular and functional information in certain settings. Postprocessing techniques such as multiplanar reformatting, volume rendering, and virtual bronchoscopy assist in surgical planning by providing a better representation of three-dimensional anatomy. A systematic approach to imaging the airway based on clinical symptoms and signs is essential for the prompt, safe, and accurate diagnosis of tracheobronchial disorders in children.

Index of Suspicion

Index of Suspicion

The Role of Airway Fluoroscopy in the Evaluation of Stridor in Children

The Role of Airway Fluoroscopy in the Evaluation of Stridor in Children

Advances in pediatric airway radiology.

Radiologic evaluation of the airway has been used as a screening tool and an adjunct to endoscopy for many years. It provides noninvasive data on the structure of the airway while avoiding the risk of general anesthesia. In the past, standard radiographs provided only a shadow of the intricate anatomy of the pediatric airway. Not only have there been advances in static imaging but there now exists technology that enable noninvasive dynamic imaging and new techniques for image-guided intervention within the airway. This article focuses on four specific areas: airway fluoroscopy, functional swallow studies, controlled ventilation computed tomography, and interventional airway techniques.

Comparison of endoscopy and radiographic fluoroscopy in the evaluation of pediatric congenital airway abnormalities

In order to assess the accuracy of conventional dynamic radiographic studies compared to endoscopy in the diagnosis of congenital airway abnormalities, we performed a retrospective chart review for the period between July 1991 to June 1996. A total of 186 patients were identified who required hospitalization for their respiratory status as a result of a congenital airway abnormality. Of these, 19% had both endoscopy and conventional dynamic radiographic evaluation (airway fluoroscopy, barium esophagography, or both). Eleven percent had fluoroscopy only, 62% had endoscopy only, and 9% had neither. In those patients who underwent both endoscopic and conventional dynamic radiographic evaluation, endoscopy was considered to be the definitive procedure for diagnosis. Laryngomalacia was present in 94% of these patients. Thirteen patients had multiple sites of airway abnormalities on endoscopy, and a total of 51 abnormalities were identified. Dynamic radiographic evaluation was correct in four, was suggestive of the abnormality in 12, did not recognize an abnormality in 33, and suggested a different diagnosis (not corresponding to endoscopy) in two. Thus, airway fluoroscopy and/or barium esophagography were correct or suggestive in 16 of 51 abnormalities (31%). We conclude that endoscopy is required in the majority of hospitalized patients for the precise diagnosis of a congenital airway abnormality. Conventional dynamic radiographic studies are helpful to confirm a suspected diagnosis in patients with a strong clinical history and physical examination. When the diagnosis is not clear based on the patient presentation, endoscopy is more definitive than conventional dynamic radiography in identifying pediatric congenital airway abnormalities.

Apical lung hernia: radiologic findings in six cases.

We performed this study to characterize the clinical and radiologic manifestations of apical lung hernias. Apical lung hernias typically manifest as unilateral, right-sided air radiolucencies at the thoracic inlet on chest radiographs. They are frequently intermittent and can cause lateral tracheal deviation. Radiologic studies performed at midinspiration may not show hernias. Airway fluoroscopy or CT performed at maximal inspiration may be necessary to confirm the diagnosis.

Radiologic evaluation of adenoids and tonsils in children with obstructive sleep apnea: plain films and fluoroscopy.

Twenty-six children with obstructive sleep apnea were evaluated by lateral neck radiographs during wakefulness, and by polygraphic monitoring and upper airway fluoroscopy during natural sleep. Children with craniofacial abnormalities, palatal surgery, and central nervous system disease were excluded from the study. Moderate or marked enlargement of tonsils and adenoids was noted on lateral neck radiographs of 18 of 26 patients. An objective measure of adenoidal enlargement, the adenoidal-nasopharyngeal ratio, correlated well with subjective judgment of adenoidal size but was not generally more useful than subjective estimation. Upper airway fluoroscopy demonstrated the site and mechanism of obstruction in all patients. Because all children with moderate to marked adenotonsillar enlargement demonstrated obstruction at the adenoidal or tonsillar level on fluoroscopy, we now screen children with suspected sleep apnea with lateral airway radiographs and polysomnography. Fluoroscopy is reserved for children with mild adenotonsillar enlargement, craniofacial dysplasia, prior cleft palate repair, or neuromuscular disorders. These results suggest that the pathogenesis of obstructive sleep apnea in children involves anatomic factors which narrow the upper airway, sleep-related hypotonia of pharyngeal dilator musculature, and compensatory mechanisms to prevent or alleviate asphyxia.

Obstructive sleep apnea in infants and children

Twenty-two infants and children were found to have clinically significant obstructive sleep apnea. A history suggesting complete or partial airway obstruction during sleep was obtained on all patients, and physical examination of the sleeping patient revealed snoring, retractions, or OSA in 21 patients. Nevertheless, the mean delay in referral for 20 patients first seen after the neonatal period was 23 +15 (+ SD) months. Sixteen of 22 patients (73%) developed serious sequelae: cor pulmonale in 12 (55%), failure to thrive in six (27%), permanent neurologic damage in two (9%), and behavioral disturbances, hypersomnolence, or developmental delays in five (23%). Clinical and radiologic evaluations revealed anatomic abnormalities which narrowed the upper airway in 21 patients; enlarged tonsils and/or adenoids in 14, micrognathia in three,generalized facial abnormalities in three, and cleft palate repair/tonsillar hypertrophy in one. In five patients, upper airway fluoroscopy was performed and was helpful in establishing the site and mechanism of obstruction. Polygraphic monitoring was utilized to quantify the frequency and duration of OSA. Prolonged partial airway obstruction during sleep resulted in significant hypercarbia in 11 patients and hypoxemia in five. Twenty patients improved after surgery which relieved or bypassed the pharyngeal airway obstruction; two cases are pending. Increased awareness of OSA and examination of the sleeping patient should result in earlier treatment and less morbidity for infants and children with OSA.

1645 NONINVASIVE EVALUATION OF UPPER AIRWAY OBSTRUCTION (UAO) IN CHILDREN

Information obtained from serial inspiratory-expiratory (I/E) flow volume (FV) curves on four children with signs and symptoms or UAO was compared to that obtained by physical examination, bronchoscopy, and airway fluoroscopy in an attempt to evaluate the usefulness of FV curves in young children. FV patterns associated with lesions of the upper airway have been described as fixed (F) UAO, variable intrathoracic (VI) UAO, and variable extrathoracic (VE) UAO. In three of the four cases (Cases 1,2,3) the FV pattern suggested a lesion of the upper airway confirmed by more conventional techniques. In Case 1, fluoroscopy alone confirmed the diagnosis suggested by the FV pattern. I/E FV patterns when combined with airway fluoroscopy, may characterize anatomic lesions of the upper airway frequently missed by less dynamic techniques.

1685 UPPER AIRWAY OBSTRUCTION (UAO) DURING SLEEP: A CLINICAL SPECTRUM

Sleep disturbance (SD) is often the presenting complaint in children who have UAO of various etiologies. We recently evaluated 9 children who presented with symptoms of SD and/or signs of UAO during sleep. They were studied with noninvasive techniques including sleeping airway fluoroscopy, respiratory gas exchange, airflow and impedance pneumography for evidence of UAO and apnea.