Fluid dynamics of the upper airway in pediatric patients with severe laryngomalacia.

Laryngomalacia is the top cause of pediatric laryngeal wheeze. We used computational fluid dynamics to study the inspiratory airflow dynamics in severe pediatric laryngomalacia. Computed tomography was performed on the upper airways of two infants, one with severe laryngomalacia and one with normal airway, and 3D models were reconstructed. ANSYS CFD-POST software was used to simulate airflow in these models to compare the volumetric flow rate, flow velocity, pressure, wall shear, and vortex. The volume flow rate in the laryngomalacia model was significantly reduced compared with the control model. Under inspiratory pressures, the peak flow velocity, pressure, and shear force in the control model appeared at the soft palate stenosis, while that in the laryngomalacia model appeared at the supraglottis stenosis. In both models, the maximum flow velocity and shear force increased with decreasing inspiratory pressure, while the minimum pressure decreased with decreasing inspiratory pressure. In the control model, the airflow vortex appeared anteriorly below the posterior section of the soft palate. In the laryngomalacia model, the vortex appeared anteriorly below the posterior section of the soft palate and anteriorly below the vocal folds. Our methodology provides a new mechanistic understanding of pediatric laryngomalacia.

The role of laryngeal ultrasound in diagnosis of infant laryngomalacia.

OBJECTIVE: The purpose of this study was to evaluate the role of laryngeal ultrasound in diagnosis of infant laryngomalacia. METHODS: Forty consecutive infant patients with inspiratory stridor or other laryngeal symptoms underwent flexible fiberoptic nasopharyngolaryngoscopy and laryngeal ultrasound examination from January 2014 to May 2014. The curling angle of the epiglottis and/or arytenoid tissue collapses on laryngeal ultrasound during inspiration were used to diagnose infant laryngomalacia. The value of laryngeal ultrasound in diagnosis of infant laryngomalacia was evaluated and further compared to that of flexible fiberoptic nasopharyngolaryngoscopy. RESULTS: The mean angle of the curling epiglottis in 26 patients with laryngomalacia was 69.1 ±â€¯8.1 degrees, while the mean angle of the slightly curling epiglottis in 12 patients without laryngomalacia was 89.6 ±â€¯9.7 degrees (p < 0.0001). Arytenoid tissue collapses were found in 24 patients with laryngomalacia and only one patient without laryngomalacia had a local collapse of arytenoid tissue (p < 0.0001). Twenty six of the 28 patients with laryngomalacia diagnosed by flexible fiberoptic nasopharyngolaryngoscopy were detected by laryngeal ultrasound. There was an excellent consistency between laryngeal ultrasound and flexible fiberoptic nasopharyngolaryngoscopy in the detection of infant laryngomalacia (κ = 0.826). Laryngeal ultrasound had a sensitivity of 96.3%, a specificity of 84.6%, a positive predictive value of 92.9%, and a negative predictive value of 91.7% in diagnosing infant laryngomalacia. CONCLUSIONS: Laryngeal ultrasound can help diagnose infant laryngomalacia through visualizing omega-shaped epiglottis and/or arytenoid tissue collapse during inspiration. The modality has an excellent consistency with flexible fiberoptic nasopharyngolaryngoscopy in diagnosis of the disease.

[Establishment and preliminary application of a laryngomalacia larynx three-dimension model].

Objective:To establish and preliminarily apply a laryngomalacia larynx three-dimension finite element model. Method:The MIMCS software was employed to deal with the Dicom images of larynx CT scan by means of distinguishing material gray threshold of different tissues. 3D visualization model of larynx was also built by this software. Hyermesh software was used to handle the grid layout of larynx finite element model. Laryngeal structure parameter were added, and laryngeal mechanical analysis were carried out by Abaqus software in order to get von Mises stress. Result:A 3D model，which finely represent the morphological characteristics of laryngomalacia larynx was built using the finite element technology. Peak von Mises stress was observed to be higher in more severe laryngomalacia case. Conclusion:The 3D finite element model of the laryngomalacia larynx provides the foundation for further study．Peak von Mises stress may be a useful indicator of laryngomalacia severity assessment.

Cricopharyngeal achalasia associated with laryngomalacia as a cause of failure to thrive.

OBJECTIVE: To describe a case of concurrent cricopharyngeal achalasia with laryngomalacia as a cause of failure to thrive, and to review the literature and management options of cricopharyngeal achalasia in the paediatric population. METHODS: A chart review was performed on a four-month-old male, referred for failure to thrive, and diagnosed with cricopharyngeal achalasia and laryngomalacia. A PubMed and Embase search for 'cricopharyngeal achalasia' and 'laryngomalacia' was conducted. A review of reported paediatric cricopharyngeal achalasia patients, with emphasis on management options, was undertaken. RESULTS: A flexible laryngoscopic examination confirmed the laryngomalacia diagnosis, and videofluoroscopic evaluation of swallowing demonstrated cricopharyngeal achalasia via a cricopharyngeal bar. Supraglottoplasty was performed, with botulinum toxin injection into the cricopharyngeus muscle, with resultant improvement in oral intake and resolution of failure to thrive. The literature review revealed no reported case of the combined pathologies as a cause of failure to thrive. CONCLUSION: Functional endoscopic evaluation of swallowing and videofluoroscopic evaluation of swallowing are complimentary in the evaluation of paediatric patients with failure to thrive and suspected oropharyngeal dysphagia. Both supraglottoplasty and botulinum toxin injection are effective for definitive management in cases of combined pathology, and can be safely performed in a single surgical setting.

Neurological manifestations of 2q31 microdeletion syndrome.

Microdeletion of 2q31 involving the HOXD gene cluster is a rare syndrome. The deletion of the HOXD gene cluster is thought to result in skeletal anomalies in these patients. HOX genes encode highly conserved transcription factors that control cell fate and the regional identities along the primary body and limb axes. We experienced a new patient with 2q31 microdeletion encompassing the HOXD gene cluster and some neighboring genes including the ZNF385B. The patient showed digital anomalies, growth failure, epileptic seizures, and intellectual disability. Magnetic resonance imaging showed delayed myelination and low signal intensity in the basal ganglia. The ZNF385B is a zinc finger protein expressed in brain. Disruption of ZNF385B was suspected to be responsible for the neurological features of this syndrome.

Are contrast swallows a relevant investigation for paediatric stridor?

The contrast swallow has traditionally been used in the investigation of paediatric stridor with the aim of identifying pathology such as vascular rings and confirming the presence of gastro-oesophageal reflux. Currently, a laryngotracheobronchoscopy (LTB) is the gold standard investigation for stridor and frequently, a child is commenced on antireflux medications based on clinical history. We seek to identify whether a contrast swallow has a valuable and cost effective role in the investigation of paediatric stridor. This was a retrospective audit study. All the children who underwent a contrast swallow as part of the investigation for stridor were identified from 2008 to 2011. All requests were made by clinicians from the ENT department at Birmingham Children's Hospital. All patient demographics and radiological reports were reviewed. The final patient list was cross referenced with theatre records to identify those that underwent a LTB The cost of the contrast swallow was identified by the contracting department at Birmingham Children's Hospital. A total of 117 contrast swallows were requested during the study period. The age range was 1 week to 50 months with an average patient age of 6 months. 45/117 (38 %) of contrast swallows identified pathology. 33/45 (73 %) demonstrated reflux. Only 12/117 (10 %) of all cases suggested pathology other than reflux. A total of 51 patients underwent LTB. 22/51 (43 %) had a subsequent contrast swallow. Since the average cost per contrast swallow in the outpatient setting was £ 77, and only 9 cases demonstrated significant unexpected pathology, 108 children had a contrast swallow that did not significantly alter the management of their stridor. 9 cases were identified in which the contrast study results altered the management of the child. An estimated £ 8,000 were spent on investigations that made no impact on the subsequent management of the child. Contrast swallows requested for the investigation of paediatric stridor identified 33 cases of gastro-oesophageal reflux and 12 cases of alternative pathology. Among those children with radiological evidence of reflux, 70 % (23/33) had already been commenced on antireflux medication based on their clinical symptoms. Only 8 % of findings from a contrast swallow investigation resulted in a change to the management of the stridulous child. The authors suggest that it is more cost effective to reserve requests for a contrast swallow until the diagnostic LTB is performed. This strategy will not only reduce exposure to ionising radiation in a significant number of children, but also identifies airway pathology more effectively and ensures that contrast swallows are used as an appropriate adjunctive diagnostic investigation.

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

OBJECTIVES/HYPOTHESIS: 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. STUDY DESIGN: Retrospective chart review. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.