Neonatal subglottic stenosis--incidence and trends

Subglottic Stenosis After Pediatric Tracheostomy

OBJECTIVES

To determine the incidence of subglottic stenosis (SGS) in children after tracheostomy and identify risk factors for development.

STUDY DESIGN

Retrospective cohort.

METHODS

All patients (<18 years) undergoing tracheostomy at a tertiary children's hospital between 2015 and 2020 were included. Patients with a direct laryngoscopy (DL) concurrent with tracheostomy and a subsequent DL were included. Medical records, including operative reports, were reviewed to identify subglottic stenosis and associated risk factors.

RESULTS

A total of 140 patients were included with mean age at tracheostomy of 2.4 years (standard deviation [SD]: 4.3) (median: 0.5 years, interquartile range [IQR]: 0.3-1.5 years) and gestational age of 33.8 weeks (SD: 5.9) (median: 36 weeks, IQR: 28-39 weeks). At initial DL, 24% (N = 34) had subglottic injury and 26% (N = 37) developed SGS. The incidence of SGS after tracheostomy was 11.5 cases per 100 patients per year. At tracheostomy, lower birth weight (1.8 vs. 2.3 kg, p = 0.005), shorter gestational age (31.8 vs. 34.6 weeks, p = 0.01), younger age (0.8 vs. 2.9 years, p = 0.01), lower weight (5.8 vs. 14.7 kg, p = 0.01), and subglottic injury (44% vs. 21%, p = 0.01) were associated with the development of SGS. Multivariable logistic regression analysis associated birth weight (odds ratio [OR]: 0.49, 95% confidence interval [CI]: 0.31-0.75, p = 0.001) and early subglottic injury (OR: 3.22, 95% CI: 1.31-7.88, p = 0.01) with SGS development.

CONCLUSIONS

The incidence of SGS after pediatric tracheostomy is estimated at 11.5 cases per 100 patients per year. Low birth weight and subglottic injury at the time of tracheostomy were associated with SGS in this vulnerable population of children.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

Endoscopic balloon dilatation for pediatric subglottic stenosis: a meta-analysis of successful outcomes

OBJECTIVES

The primary goal of this study was to systematically identify all relevant published articles on the use of primary endoscopic balloon dilation for the management of pediatric patients with subglottic stenosis, critically assess the technique's success, and determine which patients are the best candidates for the procedure.

METHODOLOGY

This was a systematic review and meta-analysis that aimed to investigate the use and success rate of EBD for treating pediatric SGS. An electronic systematic literature search of three major databases, PubMed, EBSCO, and Web of Science&MEDLINE through Clarivate, was conducted to include the eligible articles.

RESULTS

A total of 14 unique studies were included in the final analysis, with 473 cases of pediatric SGS. The pooled success rate of EBD in treatment of pediatric SGS was 76% (k = 14 studies, 95% confidence interval [CI] = 0.65-0.86, P < 0.001, Q test for heterogeneity = 0.03, P < .001, I2 = 91%).

CONCLUSIONS

We reported a high success rate of EBD in treating pediatric SGS. The reported complications were uncommon, although they can be serious and life threatening. The intensity of SGS may be related to the likelihood of therapy failure.

Intermittent apnoea and manual jet ventilation: A successful anesthetic management for infant with acquired Myer-Cotton class III subglottic stenosis undergoing endoscopic balloon dilatation

Acquired subglottic stenosis is a common complication of endotracheal intubation in infants. The risk increases in trisomy 21, patients undergoing bypass surgery, and having gastroesophageal reflux disease. Less invasive endoscopic balloon dilatation of subglottic stenosis has become a more common treatment modality compared to open surgical technique. Airway-related surgery needs meticulous preparation and good communication between the anesthetist, surgeon, and staff. More precaution and more effective preparation and communication are needed in neonatal airway surgery as it is physiologically easier to desaturate and develop hypoxemia compared to adults. We report a case of successful balloon dilation of Myer-Cotton class III subglottic stenosis with intermittent supraglottic jet ventilation and bag-mask ventilation in infants with trisomy 21.

Surgical Outcomes by Early Airway Endoscopy Findings after Pediatric Staged Laryngotracheoplasty

OBJECTIVES

To determine how initial postoperative airway endoscopy findings after stent removal predict successful decannulation in children undergoing double-staged laryngotracheoplasty (dsLTP). Secondary objectives assessed timing of decannulation and number of endoscopic interventions needed after dsLTP.

METHODS

A case series with chart review included children who underwent dsLTP at a tertiary children's hospital between 2008 and 2021. Rates of decannulation, time to decannulation, and number of interventions after dsLTP were recorded for children with high- or low-grade stenosis at the first bronchoscopy after stent removal.

RESULTS

Of the 65 children who were included, 88% had high-grade stenosis and 98% had a preoperative tracheostomy. Successful decannulation happened in 74% of the children, and 44% of the children were decannulated within 12 months of surgery. For children with low-grade stenosis at the first endoscopy after stent removal, 84% were successfully decannulated compared with 36% of the children with high-grade stenosis (p = 0.001). After dsLTP, children with high-grade stenosis required 7.5 interventions (SD: 3.3) compared with 4.0 interventions (SD: 3.0) for children with low-grade stenosis (p < 0.001). Decannulated children with high-grade stenosis necessitated more endoscopic procedures (7.0 vs. 3.7, p = 0.02). Time to decannulation was similar between children with high- and low-grade early postoperative stenosis (21.9 vs. 17.8 months, p = 0.63).

CONCLUSIONS

Higher grade stenosis identified on the first airway endoscopy after suprastomal stent removal is correlated with lower decannulation rates and more postoperative endoscopic interventions. Although time to decannulation was not impacted by early stenosis grade, surgeons might utilize these early airway findings to counsel families and prognosticate possible surgical success.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:963-967, 2024.

Airway disease decreases the therapeutic potential of epithelial stem cells

BACKGORUND

Tissue-engineered tracheal grafts (TETG) can be recellularized by the host or pre-seeded with host-derived cells. However, the impact of airway disease on the recellularization process is unknown.

METHODS

In this study, we determined if airway disease alters the regenerative potential of the human tracheobronchial epithelium (hTBE) obtained by brushing the tracheal mucosa during clinically-indicated bronchoscopy from 48 pediatric and six adult patients.

RESULTS

Our findings revealed that basal cell recovery and frequency did not vary by age or region. At passage 1, all samples produced enough cells to cellularize a 3.5 by 0.5 cm2 graft scaffold at low cell density (~ 7000 cells/cm2), and 43.75% could cellularize a scaffold at high cell density (~ 100,000 cells/cm2). At passage 2, all samples produced the number of cells required for both recellularization models. Further evaluation revealed that six pediatric samples (11%) and three (50%) adult samples contained basal cells with a squamous basal phenotype. These cells did not form a polarized epithelium or produce differentiated secretory or ciliated cells. In the pediatric population, the squamous basal cell phenotype was associated with degree of prematurity (< 28 weeks, 64% vs. 13%, p = 0.02), significant pulmonary history (83% vs. 34%, p = 0.02), specifically with bronchopulmonary dysplasia (67% vs. 19%, p = 0.01), and patients who underwent previous tracheostomy (67% vs. 23%, p = 0.03).

CONCLUSIONS

In summary, screening high-risk pediatric or adult population based on clinical risk factors and laboratory findings could define appropriate candidates for airway reconstruction with tracheal scaffolds.

LEVEL OF EVIDENCE

Level III Cohort study.

Anesthetic management of inguinal hernia in an ex-premature infant with subglottic stenosis: a case report

BACKGROUND

We report the anesthetic management of inguinal hernia repair for an infant with subglottic stenosis. A previously scheduled operation had been cancelled due to unexpected airway trouble during the induction.

CASE PRESENTATION

A boy was born at 24 weeks of gestation and his trachea was intubated for 45 days. At 16 months old, surgery for inguinal hernia was planned, but cancelled due to unexpected narrow airway, and subglottic stenosis was first suspected. At 17 months old, he was transferred to us for inguinal hernia surgery. After careful discussion between the surgical team and the anesthesiologists, a strategy to manage this patient was developed. He underwent open hernia surgery under spinal anesthesia and diagnostic rigid bronchoscopy under tubeless general anesthesia separately, which revealed low-grade stenosis and some subglottic cysts. The postoperative course was uneventful.

CONCLUSION

Interdepartmental discussion weighing risks and benefits may deduce the safest and most appropriate anesthesia method.

Obstructive sleep apnea is associated with use of assisted ventilation among children with bronchopulmonary dysplasia hospitalized with respiratory illness: A nationwide inpatient cohort

OBJECTIVE (S)

Children with bronchopulmonary dysplasia (BPD) are at higher risk of respiratory insufficiency during respiratory illness. We aimed to investigate whether obstructive sleep apnea (OSA) is associated with increased morbidity among children with BPD hospitalized with acute respiratory illnesses.

STUDY DESIGN

Hospital discharge records were obtained from the Kid's Inpatient Database for children <21 years of age with BPD hospitalized for acute respiratory illness between 1997 and 2012. Acute respiratory illnesses included bacterial and/or viral pneumonia, bronchiolitis, acute upper respiratory tract infections, aspiration pneumonia, or asthma exacerbation. The primary exposure was OSA. The primary outcome was invasive mechanical ventilation (IMV), and secondary outcomes were noninvasive mechanical ventilation (NIMV), length of hospital stay (LOS), and inflation-adjusted cost of hospitalization (IACH). Multivariable regression was conducted to ascertain the associations between OSA and primary and secondary outcomes accounting for BPD-associated comorbidities.

RESULTS

Among 33,640 hospitalizations of children with BPD for acute respiratory illness, there were 607 (1.8%) cases with comorbid OSA vs. 33,033 (98.2%) controls without OSA. Patients with OSA were more likely to have aspiration pneumonia, central sleep apnea, obesity, laryngeal stenosis, congenital airway, and skull/face/jaw anomalies. Multivariable regression showed that OSA was associated with IMV (OR 1.45, 95% CI 1.09-1.94, p = 0.012) and NIMV (OR 2.61, 95% CI 1.71-3.98, p < 0.001), but not LOS or IACH.

CONCLUSIONS

In BPD patients hospitalized with acute respiratory illness, having OSA is associated with increased risks for respiratory insufficiency requiring noninvasive or invasive mechanical ventilation. Clinicians should consider OSA, along with other BPD-associated comorbidities, in the management of this population.

[Paediatric Airway Surgery - Indications and Techniques]

Even in specialised centres, surgical procedures on the airway are only rarely performed in paediatric patients. Moreover, knowledge of various specific anatomical characteristics, diseases and surgical techniques is a prerequisite to treat these patients. Most commonly, sequelae of long-term intubation or tracheostomy in multimorbid patients necessitate surgical repair. Moreover, congenital malformations of the airways might require surgical interventions. However, these are commonly associated with other organ malformations, which adds further complexity to the treatment concept. Thus, cooperation within an interdisciplinary team is absolutely necessary to treat these patients. However, good postoperative outcomes after paediatric airway surgery can be achieved in experienced centres with an appropriate infrastructure. Specifically, this means long-term tracheostomy-free survival with preserved laryngeal functions in most of the patients. This review provides a summary of common indications and surgical techniques in paediatric airway surgery.

Development and Disorders of the Airway in Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD), a disorder characterized by arrested lung development, is a frequent cause of morbidity and mortality in premature infants. Parenchymal lung changes in BPD are relatively well-characterized and highly studied; however, there has been less emphasis placed on the role that airways disease plays in the pathophysiology of BPD. In preterm infants born between 22 and 32 weeks gestation, the conducting airways are fully formed but still immature and therefore susceptible to injury and further disruption of development. The arrest of maturation results in more compliant airways that are more susceptible to deformation and damage. Consequently, neonates with BPD are prone to developing airway pathology, particularly for patients who require intubation and positive-pressure ventilation. Airway pathology, which can be divided into large and small airways disease, results in increased respiratory morbidity in neonates with chronic lung disease of prematurity.

[Airway Management in Paediatric Anaesthesia]

Due to their low reserves, hypoxia and cardiac arrest occur rapidly in children. The continuous securing of the airway as well as maintenance of oxygenation and ventilation are of prior importance in paediatric anaesthesia. For this purpose, bag-mask ventilation and the opening of the upper airway must be trained and mastered in particular. As the most important supraglottic device, the laryngeal mask has been evaluated for patients of all ages.

Management of balloon dilatation in cases of subglottic stenosis in children: success and failure

PURPOSE

To assess efficacy and prognostic factors of endoscopic balloon dilatation for the treatment of subglottic stenosis in children.

METHODS

A retrospective review was performed on 49 pediatric patients with subglottic stenosis treated at the Shanghai Children's Hospital between December 2017 and December 2021. Specific demographic data, type and severity of the stenosis, number of balloon dilatations and outcomes were recorded and analyzed.

RESULTS

Forty-nine children (30 male, 19 female) were included in the study with a median age at diagnosis of 24 (13-36.5) months, of which 7 (14.3%) had received open laryngotracheal reconstruction previously. The degree of subglottic stenosis was grade I in six patients, grade II in 16 patients, grade III in 20 patients and grade IV in seven patients. After various numbers of balloon dilatations (1-7 times), 29 patients showed a good outcome (decannulation or prevention of tracheostomy) and the success rate in that series was 59.2%. Overall, prognosis of balloon dilatation was not dependent on pathogeny (congenital or acquired) or open surgical history(P > 0.05), but rather on the severity grade of stenosis and the number of dilatations (P < 0.05).

CONCLUSIONS

Endoscopic balloon dilatation can be safe and effective in the treatment of subglottic stenosis in children, except for more serious cases (grade IV). Open surgery should be considered if no significant improvement is observed after dilatation, especially after three or more dilatations.

Airway Management in Pediatric Patients: Cuff-Solved Problem?

Traditionally, uncuffed tubes were used in pediatric patients under 8 years in pursuit of reducing the risk of postextubation stridor. Although computed tomography and magnetic resonance imaging studies confirmed that the subglottic area remains the narrowest part of pediatric airway, the use of uncuffed tubes failed to reduce the risk of subglottic swelling. Properly used cuffed tubes (correct size and correct cuff management) are currently recommended as the first option in emergency, anesthesiology and intensive care in all pediatric patients. Clinical practice particularly in the intensive care area remains variable. This review aims to analyze the current recommendation for airway management in children in emergency, anesthesiology and intensive care settings.

Imaging in neonatal respiratory disease

The purpose of this review is to describe the current state of the art in clinical imaging for NICU patients, divided into major areas that correspond to likely phenotypes of neonatal respiratory disease: airway abnormalities, parenchymal disease, and pulmonary vascular disease. All common imaging modalities (ultrasound, X-ray, CT, and MRI) are discussed, with an emphasis on modalities that are most relevant to the individual underlying aspects of disease. Some promising aspects of dynamic and functional imaging are included, where there may be future clinical applicability.

Clinical effectiveness of treating laryngotracheal stenosis with free hyoid bone reconstruction of the cricoid cartilage: A case series

We reported the free hyoid bone reconstruction of the cricoid cartilage to treat LTS in children. This retrospective case series study included LTS children who underwent hyoid bone separation and T tube implantation. Thirty-four children were included. Twenty-five children were with good outcomes after free hyoid bone reconstruction of the cricoid cartilage. Specifically, the cure rate was 92.8% for the children with mixed stenosis, followed by 63.6% in children with glottis stenosis and 55.6% in children with subglottic stenosis. Free hyoid bone reconstruction of the cricoid cartilage for the management of LTS is feasible, with good outcomes and few complications.

Establishment of two canine models of benign airway stenosis and the effect of mitomycin C on airway stenosis

OBJECTIVES

Cuffed endotracheal intubation and stent implantation were employed to simulate two types of benign airway stenosis and further to analysis the different features between them from trachecscopic characteristics, gross anatomy to histopathological changes. In addition, our study explored the therapeutic effect of mitomycin C at different concentrations on granulation tissue caused by stent implantation in order to provide a new therapeutic strategy for clinical treatment of benign airway stenosis.

METHODS

Twelve beagle dogs were randomly divided into four groups, with three dogs in each group. Group A: Three beagle dogs were intubated through oral trachea after general anesthesia and cuff pressure maintained at 200 mmHg for 24 h. Group B, Group C and Group D: endotracheal coated self-expanding metal stents were placed after general anesthesia under the guidance of bronchoscope. On the Day7 after stent implantation, Group B, as control group, was injected phosphate buffer solution of 1 ml into granulation tissue at the end of stent; Group C was injected mitomycin C of 1 ml at 0.4 mg/ml and Group D was injected mitomycin C of 1 ml at 0.8 mg/ml into granulation tissue at the end of metal airway stent respectively, the same method as Group B. Bronchoscopy was used to observe tracheal lumen on the seventh day, fourteenth day and twenty-first day after modeling and pathological changes were examined on twenty-first day.

RESULTS

Two models of benign airway stenosis can be established by cuffed endotracheal intubation and stent implantation. There was tracheal rupture in the trachea cartiage ring in the cuffed endotracheal intubation group, but was't in stent implantation group. Histopathological characteristics were different between cuffed endotracheal intubation and stent implantation groups. In stent placement groups, we found that the stenosis degree of mitomycin C at 0.4 mg/ml was approximately 19%-32%, mitomycin C at 0.8 mg/ml was approximately 16%-21% and the control group was approximately 36%-47%.

CONCLUSION

The two models of canine benign tracheal stenosis induced by cuffed endotracheal intubation and stent implantation are relatively simple, reliable and reproducible and have different characteristics. Mitomycin C could inhibit proliferation of granulation tissue and attenuate the degree of airway stenosis caused by stent implantation.

Long-term results of slide laryngotracheoplasty for congenital subglottic stenosis in newborns and infants

OBJECTIVES

Slide laryngotracheoplasty is an effective, single-step procedure without tracheostomy and stenting for treating high-grade congenital subglottic stenosis in neonates and infants. Long-term outcomes were evaluated to assess the reliability of the procedure performed in this age of rapid development of the laryngeal structures.

METHODS

We report five children who underwent slide laryngotracheoplasty before the age of 4 months, each with >3 years follow-up. Increases of length and bodyweight were systematically assessed. Breathing, swallowing, voice, and overall satisfaction was assessed by a quality of life questionnaire. Voice quality was objectively evaluated by measuring shimmer, jitter, fundamental frequency, and the harmonics-to-noise ratio.

RESULTS

All patients had a stable and adequate airway during follow-up without any additional open airway surgery. The patients' voices were physiological, and the intervention had no negative impact on speech development. Swallowing function was optimally retained, and the patients' bodyweight gain and length were satisfactory. During at least 3 years of observation, the anastomosis remained stable and grew dynamically with the patient.

CONCLUSIONS

Slide laryngotracheoplasty (as a single-step procedure) provides an adequate airway without tracheostomy, grafting, or stenting with good long-term functional results in selected neonates and infants with congenital subglottic stenosis.

Pädiatrische Atemwegschirurgie: Indikationen und Techniken

In der pädiatrischen Atemwegschirurgie sind zahlreiche anatomische Besonderheiten, spezifische Krankheitsbilder sowie spezielle Operationstechniken zu beachten. Auch an spezialisierten Zentren sind diese Eingriffe bei pädiatrischen Patienten eher selten. Ätiologisch handelt es sich meist um erworbene Stenosen als Folge von Frühgeburtlichkeit, Langzeitintubation oder -tracheotomie, welche typischerweise in Kindern mit zahlreichen Komorbiditäten auftreten. Kongenitale Fehlbildungen der Atemwege gehen häufig mit weiteren Malformationen einher, welche die erfolgreiche Behandlung zusätzlich erschweren. Voraussetzung zur Behandlung dieser Kinder sollte daher ein multidisziplinäres Team sein. An erfahrenen Zentren mit entsprechender Infrastruktur kann die chirurgische Behandlung dieser Kinder mit sehr guten Ergebnissen durchgeführt werden. So wird bei den meisten Patienten nach chirurgischer Behandlung eine sehr gute Lebensqualität ohne Notwendigkeit einer Langzeittracheostomie erreicht. Diese Übersichtsarbeit fasst die wichtigsten Indikationen, sowie die häufigsten Operationstechniken in der pädiatrischen Atemwegschirurgie zusammen.

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.

Incidence of Post-extubation Stridor in Infants With Cuffed vs. Uncuffed Endotracheal Tube: A Retrospective Cohort Analysis

BACKGROUND

Endotracheal intubation is a common procedure in Neonatal Intensive Care. While cuffed endotracheal tubes (ETT) are the standard of care in adults and children, their use in infants is controversial. The aim of this study was to compare the incidence of post-extubation stridor between uncuffed and cuffed ETTs in infants. We further evaluated the safety of cuffed ETTs in infants with a bodyweight between 2 and 3 kg and performed baseline analysis on development of subglottic stenosis.

METHODS

In this retrospective study, we screened all infants admitted to two NICUs of the Medical University of Vienna between 2012 and 2019.The study cohort was screened twice: In the first screening we selected all infants who underwent the first intubation when attaining a bodyweight >2 kg (but <6 kg) to analyze the incidence of post-extubation stridor and only considered the first intubation of each included infant. Post-extubation stridor was defined as the administration of either epinephrine aerosol or any corticosteroid within 6 h post-extubation. In the second screening we searched for all infants diagnosed with acquired severe subglottic stenosis during the study period regardless their bodyweight and numbers of intubations.

RESULTS

A total of 389 infants received at least one intubation during the study period. After excluding infants who underwent the first intubation below a bodyweight of 2 kg, 271 infants remained for final analysis with an average gestational age of 38.7 weeks at the time of intubation. Among those, 92 (33.9%) were intubated with a cuffed and 179 (66.1%) with an uncuffed ETT. Seven infants (2.6%) developed a clinically significant stridor: five of those were intubated with a cuffed and two with an uncuffed ETT (71.4 vs. 28.6%, p = 0.053). All of them had a bodyweight >3 kg at the time of intubation. Infants who developed subglottic stenosis were more often intubated with an uncuffed ETT.

CONCLUSION

In this study, no difference in the incidence of post-extubation stridor between cuffed and uncuffed ETTs in infants with a bodyweight from 2 to 6 kg could be found. The use of uncuffed ETTs does not exhibit higher risk for the acquired subglottic stenosis in this cohort.

Airway Obstruction from a Tracheal Mass in a 5-Year-Old: A Case Report

ABSTRACT

Stridor is a common presenting symptom for children in emergency departments (EDs) and usually represents an infectious process, such as croup, or aspiration of a foreign body. We present the case of an otherwise healthy 5-year-old girl with episodic increased work of breathing for several months that was initially diagnosed as asthma by her primary care physician. She subsequently presented to the ED with acutely worsening noisy breathing and dyspnea. Patient and parent denied any recent foreign body ingestions or choking episodes. We gave multiple doses of racemic epinephrine in the ED without symptom improvement. A lateral neck x-ray showed an occlusive subglottic airway mass. Otolaryngology (ENT) evaluation demonstrated an 85% airway occlusion. The mass was partially resected, resolving all of her respiratory symptoms. Although primary airway tumors in children are rare, they must be considered on the differential diagnosis of new noisy breathing or respiratory distress. Failure to diagnose these tumors in a timely manner can be life-threatening.

Central airway issues in bronchopulmonary dysplasia

While there is a very large focus on the abnormalities of parenchymal lung development and extensive efforts to minimize alveolar damage with "gentle ventilation" and noninvasive respiratory support for neonates with bronchopulmonary dysplasia (BPD), there is relatively little consideration for the implications of central airway disease in this patient population. There are significant changes in the structure and conformation of the central airway during the last half of gestation, and premature birth disrupts this natural developmental process. The arrest of maturation results in a smaller airway that is more compliant, easier to deform, and more susceptible to damage. Consequently, neonates with BPD are prone to developing central airway pathology, particularly for patients who require intubation and positive pressure ventilation. Central airway disease can be divided into dynamic and fixed airway obstruction and results in increased respiratory morbidity in neonates with chronic lung disease of prematurity.

Role of Flexible Bronchoscopy in Ventilator-Dependent Neonates

Objective

To assess the usefulness and safety of flexible bronchoscopy in ventilated neonates with extubation failure.

Method

This was a prospective observational study. Flexible bronchoscopy was done in eligible patients with failure of extubation form invasive ventilation. The main outcome measure was to find the presence of any anatomic or dynamic abnormalities of the airways of these patients and the organism profile of bronchoalveolar lavage (BAL) fluid.

Results

Forty-eight babies (68.8% preterm) were enrolled in the study. The most common finding on bronchoscopy was airway edema seen in 13 (27%) patients. BAL culture was positive in 29 (74%) patients. Overall treatment was modified in 35 (73%) patients based on bronchoscopy findings/BAL culture. Majority of infants (83.3%) tolerated the procedure very well.

Conclusion

Flexible bronchoscopy provides useful information in the management of newborn babies with extubation failure.

Respiratory setback associated with extubation failure in extremely preterm infants

BACKGROUND AND OBJECTIVES

Extubation failure in preterm infants is associated with an increased risk of mortality and morbidity. There is limited evidence to suggest if the increased morbidities are due to inherent differences among infants who fail or succeed; or whether these are due to a true respiratory setback among those who fail extubation. The aim of this study was to evaluate the respiratory status of infants who fail extubation and to assess the time taken for these infants to achieve pre-extubation respiratory status.

METHODS

This was a retrospective study of infants with birth weight ≤ 1250 g who were born between January 2009 and December 2016. Infants were eligible if they failed first elective extubation. Extubation failure was defined as need for re-intubation within 5 days of extubation. Ventilator settings, blood gas parameters, respiratory severity score (RSS), and ventilation index (VI) were used to assess the respiratory status of infants.

RESULTS

Out of 384 infants, 76% were successful and 24% failed extubation. Among those who failed extubation 91%, 77%, and 56% infants remained intubated at 24 h, 72 h, and 7 days, respectively. Respiratory status was worse at 24 and 72 h after re-intubation when compared to pre-extubation levels. The median times for RSS and VI to reach pre-extubation levels were 4 and 7 days, respectively.

CONCLUSION

Among preterm infants, failed elective extubation is associated with a significant setback in the respiratory status. Infants who fail an extubation attempt may not achieve pre-extubation respiratory status for many days after reintubation.

Acquired tracheal stenosis: Cervical slide tracheoplasty

Acquired tracheal stenosis can result from iatrogenic injury or, less commonly, tracheal tumors. Symptoms can arise insidiously and typically include respiratory distress, sleep disordered breathing, or exercise intolerance. Diagnostic evaluation includes cross-sectional imaging and endoscopy. Various endoscopic and open procedures exist to address acquired tracheal stenosis and treatment should be tailored to the patient. Cervical slide tracheoplasty without cardiopulmonary bypass is a versatile technique that can address different types of tracheal stenosis. It allows for immediate reconstruction with vascularized tissue and continued opportunity for growth as the child ages, with high success rates with minimal morbidity.

Synthetic Simulator for Surgical Training in Tracheostomy and Open Airway Surgery

OBJECTIVE(S)

To create and validate a synthetic simulator for teaching tracheostomy and laryngotracheal reconstruction (LTR) using anterior costal cartilage and thyroid ala cartilage grafts.

METHODS

A late adolescent/adult neck and airway simulator was constructed based on CT scans from a cadaver and a live patient. Images were segmented to create three-dimensional printed molds from which anatomical parts were casted. To evaluate the simulator, expert otolaryngologists - head and neck surgeons performed tracheostomy and LTR using anterior costal cartilage and thyroid ala cartilage grafts on a live anesthetized porcine model (gold standard) followed by the synthetic simulator. They evaluated each model for face validity (realism and anatomical accuracy) and content validity (perceived effectiveness as a training tool) using a five-point Likert scale. For each expert, differences for each item on each simulator were compared using Wilcoxon Signed-Rank tests with Sidak correction.

RESULTS

Nine expert faculty surgeons completed the study. Experts rated face and content validity of the synthetic simulator an overall median of 4 and 5, respectively. There was no difference in scores between the synthetic model and the live porcine model for any of the steps of any of the surgical procedures.

CONCLUSION

The synthetic simulator created for this study has high face and content validity for tracheostomy and LTR with anterior costal cartilage and thyroid ala cartilage grafts and was not found to be different than the live porcine model for these procedures.

LEVEL OF EVIDENCE

5 Laryngoscope, 131:E2378-E2386, 2021.

Tracheocutaneous Fistula After Pediatric Open Airway Reconstruction

OBJECTIVES

Tracheocutaneous fistula (TCF) is a common occurrence after pediatric tracheostomy decannulation. However, the persistence of TCF after staged reconstruction of the pediatric airway is not well-described. The primary objective was to determine the rate of persistent TCF after successful decannulation in children with staged open airway reconstruction.

METHODS

A case series with chart review of children who underwent decannulation after double-stage laryngotracheal reconstruction between 2017 and 2019.

RESULTS

A total of 26 children were included. The most common open airway procedure was anterior and posterior costal cartilage grafting (84.6%, 22/26). Median age at decannulation was 3.4 years (IQR: 2.8-4.3) and occurred 7.0 months (IQR: 4.3-10.4) after airway reconstruction. TCF persisted in 84.6% (22/26) of children while 15.4% (4/26) of stomas closed spontaneously. All closures were identified by the one-month follow-up visit. There was no difference in age at tracheostomy (P = .86), age at decannulation (P = .97), duration of tracheostomy (P = .43), or gestational age (P = .23) between stomas that persisted or closed. Median diameter of stent used at reconstruction was larger in TCFs that persisted (7.0 mm vs 6.5 mm, P = .03). Tracheostomy tube diameter (P = .02) and stent size (P < .01) correlated with persistence of TCF on multivariable logistic regression analysis. There were 16 surgical closure procedures, which occurred at a median of 14.4 months (IQR: 11.4-15.4) after decannulation. Techniques included 56.3% (9/16) by primary closure, 18.8% (3/16) by secondary intention and 25% (4/16) by cartilage tracheoplasty. The overall success of closure was 93.8% (15/16) at latest follow-up.

CONCLUSIONS

Persistent TCF occurs in 85% of children who are successfully decannulated after staged open airway reconstruction. Spontaneous closure could be identified by 1 month after decannulation and was more likely when smaller stents and tracheostomy tubes were utilized. Surgeons should counsel families on the frequency of TCF and the potential for additional procedures needed for closure.

Quantitative Evaluation of Subglottic Stenosis Using Ultrashort Echo Time MRI in a Rabbit Model

OBJECTIVE/HYPOTHESIS

To assess the ability of ultra-short echo time (UTE)-MRI to detect subglottic stenosis (SGS) and evaluate response to balloon dilation. To correlate measurements from UTE-MRI with endotracheal-tube (ETT)-sizing and to investigate whether SGS causes change in airway dynamics.

STUDY DESIGN

Animal research study.

METHODS

Eight adult New-Zealand white rabbits were used as they approximate neonatal airway-size. The airways were measured using ETT-sizing and 3D UTE-MRI at baseline, 2 weeks post-cauterization induced SGS injury, and post-balloon dilation treatment. UTE-MR images were acquired to determine airway anatomy and motion. Airways were segmented from MR images. Cross-sectional area (CSA), major and minor diameters (D_major and D_minor ), and eccentricity were measured.

RESULTS

Post-injury CSA at SGS was significantly reduced (mean 38%) compared to baseline (P = .003) using UTE-MRI. ETT-sizing correlated significantly with MRI-measured CSA at the SGS location (r = 0.6; P < .01), particularly at the post-injury timepoint (r = 0.93; P < .01). Outer diameter from ETT-sizing (OD) correlated significantly with D_major (r = 0.63; P < .01) from UTE-MRI at the SGS location, especially for the post-injury timepoint (r = 0.91; P < .01). Mean CSA of upper trachea did not change significantly between end-expiration and end-inspiration at any timepoint (all P > .05). Eccentricity of the upper trachea increased significantly post-balloon dilation (P < .05).

CONCLUSIONS

UTE-MRI successfully detected SGS and treatment response in the rabbit model, with good correlation to ETT-sizing. Balloon dilation increased CSA at SGS, but not to baseline values. SGS did not alter dynamic motion for the trachea in this rabbit model; however, tracheas were significantly eccentric post-balloon dilation. UTE-MRI can detect SGS without sedation or ionizing radiation and may be a non-invasive alternative to ETT-sizing.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E1971-E1979, 2021.

Surgical management of an infantile elliptical cricoid: Endoscopic posterior laryngotracheoplasty utilizing a resorbable plate

The cricoid is a circular "ring" of cartilage in the airway. When the lateral walls of the cricoid approximate, it takes the shape of an ellipse. In severe cases, this also reduces the glottic aperture and causes respiratory distress, stridor, and failure to thrive. The elliptical cricoid has limited surgical options outside of open laryngotracheal procedures and tracheostomy. Recently, alternatives to autologous grafts have been utilized in airway reconstruction to reduce harvest site morbidity and increase operating room efficiency. Herein a case is presented that demonstrates the successful use of a resorbable plate in augmenting the posterior larynx in an infant with a severely elliptical cricoid to avoid a tracheostomy.

Congenital Laryngeal Stenosis and Concomitant Birth Defects in a Term Newborn: A Case Report

Congenital laryngeal stenosis is a rare and unusual anomaly that usually presents in the first minutes after delivery as severe life-threatening respiratory distress. It may exist as an isolated entity or in association with other congenital malformations, in particular cardiac anomalies. In this paper, we present the case of an infant with prenatal suspicion of tetralogy of Fallot. Immediately after delivery, the patient required intubation, which proved difficult. He was eventually diagnosed with laryngeal stenosis requiring laryngological treatment.

A Randomized Controlled Trial of Dexamethasone as a Prophylactic Treatment for Subglottic Stenosis in a Rabbit Model

OBJECTIVE

Iatrogenic injury is a common cause of subglottic stenosis (SGS). We investigated the role of pre-injury dexamethasone as a preventive treatment for iatrogenic subglottic stenosis.

METHODS

16 New Zealand White rabbits were used in an IACUC approved study. Subjects were divided into two groups: intramuscular dexamethasone (DEX) at a dose of 2 mg/kg 15 minutes prior to an endoscopic injury to create SGS, and the same injury creation with a preoperative intramuscular saline (SAL) injection. Three independent, blinded raters evaluated endoscopic images to obtain cross sectional area (CSA) airway measurements. Rabbit airways were measured just prior to injury and at one week post-injury. All subjects were provided as-needed postoperative steroids and buprenorphine for symptoms of respiratory distress. Data analysis was performed using Student t-test. Intraclass correlation coefficients were used to assess inter-rater agreement.

RESULTS

All subjects survived to the one-week post-injury airway evaluation. There was no difference in airway size between groups prior to injury (P = .28). Subjects in the DEX group demonstrated an average stenosis of 20.3% (95% CI 10.2-30.5) at one week compared to 60.6% (95% CI 40.3-80.9) in the SAL group (P = .01). Subjects in the control group required significantly more doses of postoperative dexamethasone (P = .02). Inter-rater agreement for between raters was excellent (ICC = .88).

CONCLUSION

This is the first study to examine the role of pre-injury glucocorticoids in preventing iatrogenic subglottic stenosis. In our model, a single dose of intramuscular dexamethasone given prior to a subglottic injury resulted in a statistically significant reduction in airway stenosis. This research suggests that administering systemic dexamethasone should be considered prior to any procedure that may injure the subglottis, including traumatic intubation, to prevent iatrogenic subglottic stenosis.

Predictors of the need for tracheostomy in the neonatal intensive care unit

OBJECTIVES

Many infants in the neonatal intensive care unit (NICU) require prolonged periods of respiratory support. Microlaryngoscopy and bronchoscopy (MLB) is performed to evaluate for airway pathology and facilitate decision-making regarding further airway interventions or tracheostomy. The objectives of this study are to describe the operative findings of MLB performed on infants in the NICU and determine which pre-operative characteristics or operative findings are predictive of the need for tracheostomy.

METHODS

The medical records of preterm inpatients in the NICU at a single tertiary care hospital who underwent MLB between January 1, 2013 and January 7, 2016 were reviewed. Baseline and demographic characteristics and intra-operative findings were compared between patients who underwent tracheostomy and those who were successfully weaned from respiratory support.

RESULTS

Seventy-three preterm patients underwent MLB for respiratory failure, of whom 41 (56.2%) underwent tracheostomy. Patients who underwent tracheostomy had lower mean gestational age (27.4 vs. 30.5 weeks), higher prevalence of bronchopulmonary dysplasia (73.2% vs. 37.5%), lower mean birth weight (1.1 kg vs. 1.6 kg), and a greater number of extubation events (5.2 vs. 3.0) than those who weaned from respiratory support. Abnormal MLB findings were common in both groups, though no single MLB finding differed significantly between groups.

CONCLUSIONS

Preterm infants in the NICU with gestational age ≤30 weeks, birth weight <1.5 kg, severe pulmonary disease, and who have failed more than 3 extubation attempts are more likely to require tracheostomy.

Prematurity and associated future paediatric airway pathology: experience from a single tertiary paediatric ENT centre

PURPOSE

Enhanced management of the pre-term patient has resulted in improved survival rates in increasingly premature patients. Although prematurity predisposes to congenital airway pathology, there is also increased risk of endotracheal intubation, and therefore acquired subglottic pathology. We sought to evaluate airway pathology in children outside the neonatal period with a history of prematurity to explore the relationship between prematurity and upper airway pathologies.

METHODS

Data for patients undergoing elective microlaryngobronchoscopy (MLB) at our centre were collected prospectively over a 5-year period. Patients identified as premature were sub-classified by the grade of prematurity.

RESULTS

339 patients over 1 month of age underwent MLB, of which 56 (16.5%) were born prematurely. Of those with identified airway pathology, 49 (23.4%) were born prematurely, accounting for 32.6% of subglottic stenosis (n = 30), 24% of laryngomalacia (n = 13) and 19% of laryngeal cleft diagnoses (n = 16). 49 premature patients (87.5%) had one or more airway pathologies diagnosed. Multi-level airway pathology was seen in twelve premature infants (21.4%), demonstrating a statistically significant association (odds ratio 3.396; 95% CI 1.697-6.842; p value < 0.0016). Incidence of airway pathology, the severity of airway disease and multi-level airway pathology were not related to the grade of prematurity.

CONCLUSIONS

Premature patients account for a significant proportion of the workload within our tertiary centre due to improving neonatal care and survival in pre-term infants. We suggest early paediatric ENT evaluation for ex-premature patients with symptoms of airway pathology, with a low threshold for MLB. Improving neonatal survival rates in ever-increasing prematurity will require the further provision of specialist paediatric ENT services to manage their ongoing care.

Neonatal Aerodigestive Disorders: Epidemiology and Economic Burden

Aerodigestive disorders, those affecting the upper and lower airway or upper gastrointestinal tract, are interrelated anatomically during fetal development and functionally after birth. Successful respiration and feeding requires careful coordination to promote effective swallowing and prevent aspiration. I describe the epidemiology, including the prevalence of the most common aerodigestive disorders. The ability of an infant to feed by mouth at discharge, without a surgically placed feeding tube, is an important neurodevelopmental marker. Therefore, aerodigestive disorders have a high potential for lifelong morbidities and health care expenditures. When available, published research on related medical costs for these disorders is provided.

Keyhole anesthesia-Perioperative management of subglottic stenosis: A case report

Any narrowing in the airway presents as obstruction and with features of noisy breathing. The presence of subglottic stenosis poses a great challenge to the anesthesiologist. Diagnostic and corrective procedures by Otolaryngologist require rigid endoscopy which demands apneic ventilation. Hence, the goal of general anesthesia in the presence of subglottic stenosis requires a patent airway to maintain oxygenation and ventilation and avoid hypoxia. We present an interesting case of a preterm neonate with subglottic stenosis who was managed successfully with endoscopic release.

Subglottic Stenosis: Development of a Clinically Relevant Endoscopic Animal Model

OBJECTIVE

Develop a clinically relevant and reproducible endoscopic animal model for subglottic stenosis amenable to testing of minimally invasive therapeutic modalities.

STUDY DESIGN

Cohort study.

SETTING

Division of Laboratory Animals Research, University of Pittsburgh.

SUBJECTS AND METHODS

Subglottic stenosis was induced endoscopically via microsuspension laryngoscopy in 26 New Zealand white rabbits. A trimmed polypropylene brush connected to a novel electronic stenosis induction apparatus was used to create circumferential trauma to the subglottis. By using open source image analysis software, the cross-sectional areas of the stenotic and native airways were compared to calculate the percentage of stenosis and the Myer-Cotton classification grade.

RESULTS

Of the 26 rabbits, 24 (92%) exhibited stenosis after the first attempt. The mean percentage of airway stenosis was 57% (range, 34%-85%; SD, 15%). Five rabbits (19.2%) died on the day of stenosis induction from procedural complications. Of the 21 rabbits, 2 demonstrated no stenosis 7 days after initial injury and so underwent reinduction of airway injury, upon which they developed stenosis. Overall, 14 of the 21 rabbits (67%) exhibited moderate to severe stenosis (grade 2 or 3).

CONCLUSION

The stenosis induction apparatus reliably induced stenosis with a low mortality rate as compared with that of other methods in the literature. The device could be improved to generate a predetermined potentially reproducible grade of stenosis as desired by the operator. This method sets the stage for a clinically relevant and reproducible subglottic stenosis disease model that is amenable to testing of minimally invasive treatment modalities.

Transglottic corticosteroid injection for treatment of soft post-intubation subglottic stenosis: a retrospective analysis of 26 children

PURPOSE

Surgical treatment is generally recommended for severe subglottic lesions following traumatic endotracheal intubation in children. An alternative approach is early transglottic corticosteroid administration to reduce scar formation and prevent the need for subsequent surgical intervention. This technique has been practiced successfully for several decades at the Children's Hospital of Cologne and the outcomes of 26 subsequent patients reviewed in this analysis.

METHODS

All patients who underwent transglottic corticosteroid injection for treatment of post-intubation stridor and dyspnoea between 2012 and 2018 were identified and their records and endoscopy images analysed. Severity of the endoscopic findings was assessed using the Myer-Cotton classification (MCC) and an Expected Need for Surgical Intervention (ENSI) score (1 = inevitable; 2 = very likely necessary; 3 = probably avoidable and 4 = most likely not necessary) was recorded. Treatment was considered successful if the children had a complete resolution of clinical symptoms.

RESULTS

A total of 26 patients with a median (range) age of 1.9 (0.02-7.2) years and weight of 9.8 (1.8-25) kg were identified and included into the analysis. Endoscopic images were available for 22 children. All children underwent transglottic corticosteroid injection prior to any potential surgical treatment. A total of 22 patients (85%) improved following transglottic corticosteroid injection including 4 of 5 patients with a MCC = 3 and ENSI = 1 avoiding surgical intervention. None of the patients experienced a deterioration of clinical symptoms or endoscopic findings.

CONCLUSION

Transglottic corticosteroid injections as first-line treatment in children with severe post-endotracheal intubation trauma can successfully resolve symptoms and prevent invasive surgery.

Dynamic programming and automated segmentation of optical coherence tomography images of the neonatal subglottis: enabling efficient diagnostics to manage subglottic stenosis

Subglottic stenosis (SGS) is a challenging disease to diagnose in neonates. Long-range optical coherence tomography (OCT) is an optical imaging modality that has been described to image the subglottis in intubated neonates. A major challenge associated with OCT imaging is the lack of an automated method for image analysis and micrometry of large volumes of data that are acquired with each airway scan (1 to 2 Gb). We developed a tissue segmentation algorithm that identifies, measures, and conducts image analysis on tissue layers within the mucosa and submucosa and compared these automated tissue measurements with manual tracings. We noted small but statistically significant differences in thickness measurements of the mucosa and submucosa layers in the larynx (p  <  0.001), subglottis (p  =  0.015), and trachea (p  =  0.012). The automated algorithm was also shown to be over 8 times faster than the manual approach. Moderate Pearson correlations were found between different tissue texture parameters and the patient’s gestational age at birth, age in days, duration of intubation, and differences with age (mean age 17 days). Automated OCT data analysis is necessary in the diagnosis and monitoring of SGS, as it can provide vital information about the airway in real time and aid clinicians in making management decisions for intubated neonates.

Validation of Animal Models for Simulation Training in Pediatric Laryngotracheal Reconstruction

OBJECTIVES

To assess and compare the face (FV) and content validity (CV) of three ex vivo animal models for simulation training in pediatric laryngotracheal reconstruction (LTR).

METHODS

Feasibility of performing LTR was assessed on the head and neck of three different animals (lamb/suckling-pig/rabbit) and laryngeal dimensions and qualitative observations were recorded. A 19-item five-point Likert scale questionnaire was completed for each model to assess FV and CV. Data was prospectively collected and analyzed using descriptive and nonparametric statistics.

RESULTS

All three models were suitable for LTR simulation with laryngeal dimensions corresponding to 0-2 years (rabbit), 5-10 (pig) and >10 years (lamb model). Five trainees and five expert pediatric otolaryngologists performed LTR on each model. The overall median FV score was 5 for the lamb model (IQR 4-5), 3 for the rabbit (IQR 2-3), and 4 for the pig (IQR 4-4). The overall median CV score was 5 for the lamb (IQR 5-5), 2 for the rabbit (IQR 2-3), and 4 for the pig model (IQR 4-4). Comparison of the models demonstrated the lamb to be favored as the most realistic and practical model for simulation training in pediatric LTR, with both the lamb and the porcine model attaining validation thresholds.

CONCLUSION

Our study is the first comparative validation assessment of animal models for use in pediatric LTR simulation and it supports the use of ex vivo lamb and porcine models for use in LTR surgical skills training. The lamb model was the favored simulation model while the rabbit was considered inferior for simulation training in pediatric LTR.

LEVEL OF EVIDENCE

3b.

Subglottic stenosis in children: Our experience at a pediatric tertiary center for 8 years in South Korea

OBJECTIVE

The incidence of SGS has been reported to be less than 8% after endotracheal intubation. Therefore there is an increasing trend in the number of patients with acute acquired SGS due to mechanical ventilation in the intensive care unit. However, there have been no reports describing the treatment of SGS in children in South Korea. The objective of this study was to evaluate the management and outcomes of children with SGS at a pediatric tertiary center in South Korea over an 8-year period.

METHODS

All patients underwent microlaryngobronchoscopy (MLB) with bougination, incision using cold knife or laser and balloon dilatation. Data on age, sex, grade of SGS, number of management interventions, tracheostomy, comorbidities, mean follow-up period, complications, and outcome were reviewed from patient medical charts.

RESULTS

Twenty patients (13 [65%] males, 7 [35%] females; mean [±SD] age at the diagnostic procedure 15.26 ± 22.54 months) underwent MLB between March 2009 and December 2017. According to the Myer-Cotton scale, twelve of the 20 (60%) patients had grade III SGS, 7 (35%) had grade II and 1 (5%) had grade 1; there were no patients with grade IV SGS. Nine (45%) patients were diagnosed with acute SGS, and 11 (55%) with chronic SGS. Patients with SGS underwent MLB with interventions (mean 2.41 ± 2.23 per patient). Tracheostomy was performed in 13 of 20 (65%) patients, 2 of 9 (22.2%) with acute SGS, and 11 of 11 (100%) with chronic SGS. Two of 13 (15.3%) patients underwent successful decannulation. One of 2 (50%) patients with acute SGS underwent successful decannulation. Seven of 9 (77.7%) patients with acute SGS underwent MLB only without tracheostomy.

CONCLUSIONS

In patients with acute acquired SGS, the outcome was good due to the lower rate of tracheostomy and higher decannulation rate. Therefore, it is recommended that MLB with balloon laryngoplasty be performed at the earliest in patients with acute acquired SGS.

Pediatric acquired subglottic stenosis: Associated costs and comorbidities of 7,981 hospitalizations

OBJECTIVES

Numerous risk factors have been characterized for acquired subglottic stenosis (ASGS) in the pediatric population. This analysis explores the comorbidities of hospitalized ASGS patients in the United States and associated costs and length of stay (LOS).

METHODS

A retrospective analysis of the Kids' Inpatient Database (KID) from 2009 to 2012 for inpatients ≤ 20 years of age who were diagnosed with ASGS. International Classification of Diseases, Clinical Modification, Version 9 diagnosis codes were used to extract diagnoses of interest from 14, 045, 425 weighted discharges across 4179 hospitals in the United States. An algorithm was created to identify the most common co-diagnoses and subsequently evaluated for total charges and LOS.

RESULTS

ASGS was found in 7981 (0.06%) of total discharges. The mean LOS in discharges with ASGS is 13.11 days while the mean total charge in discharges with ASGS is $114,625; these values are significantly greater in discharges with ASGS than discharges without ASGS. Patients with ASGS have greater odds of being co-diagnosed with gastroesophageal reflux, Trisomy 21, other upper airway anomalies and asthma, while they have lower odds of being diagnosed with prematurity and dehydration. Aside from Trisomy 21 and asthma, hospitalizations of ASGS patients with the aforementioned comorbidities incurred a greater LOS and mean total charge.

CONCLUSION

Our analysis identifies numerous comorbidities in children with ASGS that are associated with increased resource utilization amongst US hospitalizations. The practicing otolaryngologist should continue to advocate interdisciplinary care and be aware of the need for future controlled studies that investigate the management of such comorbidities.

Establishment of an immortalized human subglottic epithelial cell line

Objective

Translational research into subglottic disease is restricted by the availability of primary human tissue originating from this subsite. Primary epithelial cells are also limited by their inability to survive beyond several divisions in culture outside of the body. Specific subglottic cell lines, useful for in vitro studies, have not yet been described. We therefore demonstrate what we believe to be the first immortalized subglottic epithelial cell line.

Methods

Subglottic tissue was derived from a single adult patient's neoplasia‐free human subglottic brushing specimen. Cells were immortalized using a lentiviral vector expressing simian virus 40 T antigen. Karyotyping was performed on the transformed cells using single nucleotide polymorphism array comparative genomic hybridization. Transformed cells were phenotypically characterized by light microscopy, immunohistochemistry, and electrophysiology studies.

Results

The immortalized subglottic cell line (SG01) was able to divide successfully beyond 20 passages. Karyotyping demonstrated no significant genomic imbalance after immortalization. The cells demonstrated normal epithelial morphology and cytokeratin expression throughout. SG01 cells were also successfully cultured at air–liquid interface (ALI). At ALI cells demonstrated cilia, mucus production, and relevant ion channel expression.

Conclusion

The novel SG01 subglottic epithelial cell line has been established. This cell line provides a unique resource for researchers to investigate subglottic diseases, such as subglottic stenosis.

Level of Evidence

NA. Laryngoscope, 129:2640–2645, 2019

A retrospective observational study of acquired subglottic stenosis using low-pressure, high-volume cuffed endotracheal tubes

INTRODUCTION

The safety of cuffed endotracheal tubes in the neonatal and critically ill pediatric population continues to be questioned due to the theoretical risk of acquired subglottic stenosis. The incidence of acquired subglottic stenosis in the high-risk mixed surgical and medical critically ill pediatric cohort using high-volume, low-pressure cuffed endotracheal tube policy has not yet been described. The aim of our study was to describe and evaluate the use and complication rate of cuffed ETT's in our unit over a 5-year period.

METHODS

We defined clinically significant subglottic stenosis as a positive stenotic finding of endotracheal tube-related pathology on a microlaryngoscopy within 6 months of invasive ventilation. All patients admitted through our pediatric critical care unit from January 10, 2012 to January 25, 2017 were matched against our theater management system database for the same period. We reviewed all matching patients' baseline demographics, comorbidities, intubation/endotracheal tube history, and subsequent surgical management.

RESULTS

Of 5309 pediatric critical care unit admissions (61% ventilated) and 1251 microlaryngoscopies, 23 children had endoscopic findings of clinically significant endotracheal tube-related pathology, reflecting 0.68% of all intubated patients. Eight patients developed acquired subglottic stenosis. All those requiring major surgical correction were ex-premature neonates initially intubated with uncuffed tubes in an external neonatal intensive care. No patient initially intubated with a cuffed endotracheal tube developed subglottic stenosis requiring surgical correction.

CONCLUSION

We report no single case of acquired subglottic stenosis in our cohort that required major surgical correction from a cuffed endotracheal tube during a 5-year period. The introduction of a policy of appropriate placement and maintenance of low-pressure, high-volume cuffed endotracheal tubes in the pediatric critical care unit was not associated with an increased rate of endotracheal tube-related subglottic trauma.

Feasibility of shotgun metagenomics to assess microbial ecology of pediatric tracheostomy tubes

OBJECTIVE

Biofilm formation on medical devices such as tracheostomy tubes (TTs) is a serious problem. The clinical impact of biofilms on the airway is still unclear. Biofilms may play a role in granulation tissue development, recurrent airway infections, and failure of laryngotracheal reconstructions. The microbial ecology on TTs has yet to be elucidated. The purpose of this study was to determine the feasibility of shotgun metagenomics to assess the biodistribution of microorganisms on TTs.

METHODS

Four TTs were collected from pediatric patients (1.4-10.2 years) with (n = 2) and without (n = 2) granulation tissue formation. Duration of TT placement prior to retrieval from patients ranged from 5 to 365 days. DNA extraction was performed using the MO BIO UltraClean Microbial Isolation (Mo Bio Laboratories, Carlsbad, CA). Library generation using Nextera XT adapters (Illumina Inc., San Diego, CA) and metagenomic shotgun sequencing was performed using the Illumina NextSeq500 (Illumina Inc, San Diego, CA). Salinibacter ruber, a species not found in mammalian microbiome communities, was used as a DNA standard and represented 0.7% to 5.7% of the microbiome, ensuring good quality and abundance of sample DNA.

RESULTS

Metagenomic shotgun sequencing was successful for all patients. In TTs associated with granuloma, Fusobacterium nucleatum, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae were predominant, most of which are considered pathogens. From TTs without granulomas, Neisseria mucosa, Neisseria sicca, Acinetobacter baumannii, and Haemophilus parainfluenzae were identified, primarily consistent with respiratory microbiome.

CONCLUSION

This study reveals that metagenomic shotgun sequencing of biofilms formed on pediatric TTs is feasible with an apparent difference in microbiome for patients with granulation tissue. Further studies are necessary to elucidate the pathogenesis of microbial ecology and its role in airway disease in patients with TTs.

LEVEL OF EVIDENCE

2c Laryngoscope, 129:317-323, 2019.