Neonatal subglottic stenosis--incidence and trends

A systematic review of simulated laryngotracheal reconstruction animal models

OBJECTIVES

Review of the literature to identify practical, high-fidelity, commercially available animal models for simulation training and surgical skills maintenance in laryngotracheal reconstruction (LTR).

METHODS

A systematic review of PubMed and Embase databases was conducted independently by two authors, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms included "laryngotracheal reconstruction," "laryngotracheoplasty," "pig and larynx," "sheep and larynx," and "rabbit and larynx." Articles were then assessed, identifying model cost and availability, model validation, feasibility as a training tool, and verisimilitude to pediatric LTR.

RESULTS

In total, 79 articles were considered suitable for inclusion in the study, incorporating both in vitro and in vivo models. Models utilized included rabbit (n = 69), pig (n = 7), sheep (n = 1), and goat (n = 2). The rabbit model was similar in size to the neonate, but differences in laryngeal anatomy and cartilage texture made graft insertion difficult. The anatomy of the pig, sheep, and goat larynges more closely resembled the pediatric patient, allowing improved grafting, but corresponded more in size to that of an older child. Commercial availability of the pig and sheep was considered greatest, and was reflected in cost. None of the animal models identified in the literature have been validated as a simulation tool.

CONCLUSIONS

The rabbit, sheep and pig models seemed to demonstrate the greatest potential for use as advanced pediatric airway surgery simulation models, with the rabbit model being most utilized in the literature. However, as yet there have been no models formally validated as a simulation training tool. Laryngoscope, 129:235-243, 2019.

Severe acquired subglottic stenosis in neonatal intensive care graduates: a case-control study

OBJECTIVE

To analyse current incidence and risk factors associated with severe acquired subglottic stenosis (SASGS) requiring surgical intervention in neonates.

DESIGN

Retrospective case-control study.

SETTING

Sole tertiary children's hospital.

PARTICIPANTS

Patients who underwent surgical intervention for SASGS from January 2006 to December 2014. For each neonatal intensive care unit (NICU) graduate with acquired SASGS, two controls were selected (matched for gestation and year of birth).

MAIN OUTCOMES AND MEASURES

Incidences were calculated and cases and controls compared using conditional logistic regression analysis to identify risk factors for SASGS.

RESULTS

Thirty-seven NICU graduates required surgical intervention for SASGS of whom 35 were <30-week gestation at birth. The incidence of SASGS in surviving children who had required ventilation in the neonatal period was 27/2913 (0.93%). Incidence was higher in infants <28-week gestation (24/623=3.8%) compared with infants ≥28-week gestation (3/2290=0.13%; p=0.0001). On univariate analysis, risk factors for SASGS were: higher number of intubations (4 vs 2; p<0.001); longer duration ventilation (16 vs 9.5 days; p<0.001); unplanned extubation (45.7% vs 20.0%; p=0.007); traumatic intubation (34.3% vs 7.1%; p=0.003) and oversized endotracheal tubes (ETTs) (74.3% vs 42.9%; p=0.001). On multivariate analysis, risk factors for SASGS were: Sherman ratio >0.1 (adjusted OR (aOR) 6.40; 95% CI 1.65 to 24.77); more than five previous intubations (aOR 3.74; 95% CI 1.15 to 12.19); traumatic intubation (aOR 3.37; 95% CI 1.01 to 11.26).

CONCLUSIONS

SASGS is a serious consequence of intubation for mechanical ventilation in NICU graduates, especially in preterm infants. Minimising trauma during intubations, avoiding recurrent extubation/reintubations and using appropriate sized ETTs may help prevent this serious complication.

Laryngeal stenosis among hospitalized children: Results from a nationwide cross-sectional survey

Objectives

We aimed to study laryngeal stenosis among hospitalized children in the United States from 2003–2012. We hypothesized that the prevalence of laryngeal stenosis differs by race even when controlling for age, gender, and commonly associated disease conditions.

Methods

We report the results of a cross‐sectional survey of hospitalized patients with laryngeal stenosis. We utilized the Kids Inpatient Database (KID) to estimate the odds of laryngeal stenosis as a function of race using regression analysis. The effects of age, gender, and commonly associated conditions were controlled.

Results

There were 13,910 estimated discharges of patients with laryngeal stenosis (95% CI 13,715–14,105) within the study period. This accounts for 55 cases of laryngeal stenosis per 100,000 discharges (overall prevalence = 0.22%). After controlling for age and gender, Black children had the highest likelihood of laryngeal stenosis with OR of 1.9 (95% CI 1.8–2.0, P < .001) along with children classified as Other (OR = 1.2, 95% CI 1.0–1.3, P = .03). White (OR = 0.89, 95% CI 0.83–0.89, P < .001), Hispanic (OR = 0.86, 95% CI 0.80– 0.92, P < .001), and Asian (OR = 0.53, 95% CI 0.43–0.64, P < .001) children were less likely to be diagnosed with laryngeal stenosis while Native Americans (OR = 0.96, 95% CI 0.63–1.45, P = .51) were equally likely.

Conclusions

Laryngeal stenosis is more common among hospitalized Black children, while other racial groups appear to have lower risk. This elevated risk remained when controlling for age, gender, and commonly associated conditions with laryngeal stenosis.

Level of Evidence

4

A 12-year-experience with tracheostomy for neonates and infants in northern Taiwan: Indications, hospital courses, and long-term outcomes

BACKGROUND

Tracheostomy is a valuable procedure in infants and neonates with chronic respiratory failure or severe airway obstruction. The aim of this study is to identify the indication, hospital course, and long-term outcome in a cohort of infants who required tracheostomy in a neonatal and pediatric tertiary care center in northern Taiwan.

METHODS

Medical records of infants, who underwent tracheostomy between January 2002 and December 2013, were retrospectively reviewed. Demographics, indication for tracheostomy, hospital course, discharge disposition, further hospitalization and surgery, and long-term outcome data were collected.

RESULTS

Fifty-six patients were enrolled. The median gestational age was 38.0 weeks, and median birth weight was 2770 g. he median age at tracheostomy was 104.5 days. The primary indications for tracheostomy were airway obstruction in 35 patients (62.5%), craniofacial anomalies in 7 (12.5%), neuromuscular disorder in 7 (12.5%), cardiopulmonary disorder in 5 (8.9%), and brain injury-related problem in 2 (3.6%). Twenty-two patients (39.3%) were decannulated successfully, and the median time from tracheostomy to decannulation was 2.1 years. Overall mortality rate was 3.6%, but no death was related to tracheostomy. Forty-nine patients underwent regular follow-up at our hospital, and 46 patients (93.9%) required further hospitalization, and 30 (61.2%) underwent further surgery related to a respiratory problem or tracheostomy. Ratio of delayed growth at the time of tracheostomy (28.6%) did not have significant difference at 1 year of age (21.4%) and 2 years of age (25.0%).

CONCLUSION

In this study, the most common indication for tracheostomy in neonates and infants was airway obstruction. Excluding patients with neuromuscular diseases, a successful decannulation rate of >50% can be achieved.

A Simple Endoscopic Technique for Measuring the Cross-Sectional Area of the Upper Airway in a Rabbit Model

OBJECTIVE

Validate an accurate and reproducible method of measuring the cross-sectional area (CSA) of the upper airway.

SUBJECTS AND METHODS

This is a prospective animal study done at a tertiary care medical treatment facility. Control images were obtained using endotracheal tubes of varying sizes. In vivo images were obtained from various timepoints of a concurrent study on subglottic stenosis. Using a 0° rod telescope, an instrument was placed at the level of interest, and a photo was obtained. Three independent and blinded raters then measured the CSA of the narrowest portion of the airway using open source image analysis software.

RESULTS

Each blinded rater measured the CSA of 79 photos. The t testing to assess for accuracy showed no difference between measured and known CSAs of the control images ( P = .86), with an average error of 1.5% (SD = 5.5%). All intraclass correlation (ICC) values for intrarater agreement showed excellent agreement (ICC > .75). Interrater reliability among all raters in control (ICC = .975; 95% CI, .817-.995) and in vivo (ICC = .846;, 95% CI, .780-.896) images showed excellent agreement.

CONCLUSIONS

We validate a simple, accurate, and reproducible method of measuring the CSA of the airway that can be used in a clinical or research setting.

Difficult airway associated with bifid glottis and coexistent subglottic stenosis in a patient with Pallister-Hall syndrome: a case report

Background

Pallister–Hall syndrome is a rare disorder characterized by hypothalamic hamartoma, hypopituitarism, bifid epiglottis, and micrognathia.

Case presentation

We describe the airway management under general anesthesia of a 15-year-old female with Pallister–Hall syndrome whose airway was compromised with bifid epiglottis and acquired subglottic stenosis. The three options considered for airway management were tracheal intubation, a supraglottic device, and surgical tracheotomy. Tracheal intubation provides a secured airway, but extubation can be difficult. A supraglottic device minimizes airway injury, but it does not completely protect the airway from aspiration.

Conclusions

The patient’s airway was successfully managed using a supraglottic device with aspiration prophylaxis. Airway management devices should be selected according to each patients’ individual circumstances.

Electronic supplementary material

The online version of this article (10.1186/s40981-018-0158-1) contains supplementary material, which is available to authorized users.

Cross-sectional follow-up of voice outcomes in children who have a history of airway reconstruction surgery

OBJECTIVES

This study reports vocal function in a cross-section of children with subglottic stenosis. Each child had a history of laryngotracheal reconstruction and/or cricotracheal resection surgery. Vocal function was measured using laryngoscopy, acoustic analysis, perceptual evaluation and impact of voice on quality of life.

DESIGN

All patients aged >5 years with history of laryngotracheal reconstruction and/or cricotracheal resection surgery at the Scottish National Complex Airways service were invited to participate.

SETTING

Data were gathered in the Royal Hospital for Children in Glasgow in a single outpatient appointment.

PARTICIPANTS

Twelve of 56 former patients (aged 5-27) provided a voice sample and eleven consented to awake laryngoscopy. All consented for detailed evaluation of their medical records.

MAIN OUTCOME MEASURES

Acoustic analysis of fundamental frequency and pitch perturbation was conducted on sustained vowel [a]. Perceptual evaluation was conducted by 4 trained listeners on a series of spoken sentences. Impact on quality of life was measured using the paediatric voice-related quality of life questionnaire. Laryngeal function was descriptively evaluated.

RESULTS

Four children had normal voice acoustically, perceptually and in relation to voice-related quality of life. One of these had vocal fold nodules unrelated to surgical history. Two other children had "near normal" vocal function, defined where most voice measurements fell within the normal range.

CONCLUSIONS

Normal or "near normal" voice is a possible outcome for children who have had this surgery. Where there is an ongoing complex medical condition, voice outcome may be poorer.

Reproducing severe acute subglottic stenosis in a rabbit model

OBJECTIVES

The objectives of this study were to develop an animal model with consistent, severe subglottic stenosis (SGS), and to develop the timeline needed for intervention to limit rabbit mortality.

METHODS

Subglottic stenosis was created endoscopically using either a nylon or polypropylene brush in sixteen New Zealand White rabbits. The subglottic cross-sectional area was measured endoscopically using a right-angled probe and an open source image analysis software The cross-sectional areas of the stenotic and native airways were compared to calculate the subglottic stenosis percentage and Myer-Cotton grade classification.

RESULTS

The average diameter of the native subglottis was 4.7 mm (SD 0.4). The mean subglottic stenosis percentage was 73% (SD 32) for all rabbits. The three rabbits injured with the nylon brush had 30, 52, and 76% stenosis. Nine of the 12 surviving rabbits (75%) injured with the polypropylene brush had a >86% subglottic stenosis. Four rabbits in the polypropylene brush cohort died from procedural complications.

CONCLUSION

This study demonstrates a reliable model using a polypropylene brush to create severe acute subglottic stenosis. Cartilage exposure after creating the injury was associated with more severe stenosis. Mortality rate may have been reduced if endoscopic balloon dilation was performed electively seven days after injury, rather than emergently nine days after injury.

LEVEL OF EVIDENCE

4.

Relationship between degree of obstruction and airflow limitation in subglottic stenosis

OBJECTIVES

Subglottic stenosis (SGS) is one of the most common airway disorders in pediatric patients. Currently, treatment decisions rely primarily on the Cotton-Myer scale, which classifies SGS severity based on percentage reduction in airspace cross-sectional area (CSA). However, the precise relationship between upper airway resistance and subglottic CSA is unknown. We hypothesize that airway resistance can be described by the Bernoulli Obstruction Theory, which predicts that airway resistance is inversely proportional to airspace CSA ( R∝A-1) in cases of severe constriction.

METHODS

Computed tomography (CT) scans of six healthy subjects and five SGS patients were used to create three-dimensional models of the respiratory tract from nostrils to carina. Cylindrical segments of varying lengths and varying diameters were digitally inserted in the subglottis of the healthy subjects to create simulated SGS models. Computational fluid dynamics simulations were run, and airway resistance was computed in the simulated SGS models and actual SGS models.

RESULTS

Constriction diameter had a greater impact in airway resistance than constriction length. In agreement with the Bernoulli Obstruction Theory, airway resistance in the simulated SGS models was well represented by the power law R=aAb, where a is a constant and the exponent b ranged from -0.85 to -1.07. The percentage reduction in airflow (QOBSTRUCTIONQHEALTHY) at a constant pressure drop was found to be directly proportional to the percentage reduction in CSA (AOBSTRUCTIONAHEALTHY) in the limit of severe constrictions, namely QOBSTRUCTIONQHEALTHY=kAOBSTRUCTIONAHEALTHY, where k=2.25 ± 0.15. Airway resistances in the simulated SGS models were similar to resistances in models based on CT scans of actual SGS patients, suggesting that our simulated SGS models were representative of airway resistance in actual SGS patients.

CONCLUSION

Our computer simulations suggest that the degree of airflow limitation in SGS patients may be estimated based on anatomic measurements alone. Future studies are recommended to test these predictions in larger cohorts.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1551-1557, 2018.

Markers of Successful Extubation in Extremely Preterm Infants, and Morbidity After Failed Extubation

OBJECTIVES

To identify variables associated with successful elective extubation, and to determine neonatal morbidities associated with extubation failure in extremely preterm neonates.

STUDY DESIGN

This study was a secondary analysis of the National Institute of Child Health and Human Development Neonatal Research Network's Surfactant, Positive Pressure, and Oxygenation Randomized Trial that included extremely preterm infants born at 24^0/7 to 27^6/7 weeks' gestation. Patients were randomized either to a permissive ventilatory strategy (continuous positive airway pressure group) or intubation followed by early surfactant (surfactant group). There were prespecified intubation and extubation criteria. Extubation failure was defined as reintubation within 5 days of extubation.

RESULTS

Of 1316 infants in the trial, 1071 were eligible; 926 infants had data available on extubation status; 538 were successful and 388 failed extubation. The rate of successful extubation was 50% (188/374) in the continuous positive airway pressure group and 63% (350/552) in the surfactant group. Successful extubation was associated with higher 5-minute Apgar score, and pH prior to extubation, lower peak fraction of inspired oxygen within the first 24 hours of age and prior to extubation, lower partial pressure of carbon dioxide prior to extubation, and non-small for gestational age status after adjustment for the randomization group assignment. Infants who failed extubation had higher adjusted rates of mortality (OR 2.89), bronchopulmonary dysplasia (OR 3.06), and death/ bronchopulmonary dysplasia (OR 3.27).

CONCLUSIONS

Higher 5-minute Apgar score, and pH prior to extubation, lower peak fraction of inspired oxygen within first 24 hours of age, lower partial pressure of carbon dioxide and fraction of inspired oxygen prior to extubation, and nonsmall for gestational age status were associated with successful extubation. Failed extubation was associated with significantly higher likelihood of mortality and morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00233324.

Pediatric airway surgery

The management of pediatric airway pathology can be challenging and requires a dedicated team, consisting of thoracic surgeons, phoniatricians, logopedics, pediatricians and anesthetists. It necessitates a tailored treatment approach for each individual patient in order to address the minor variances that exist between cases. The majority of pediatric airway problems are a sequela of prematurity and prolonged post-partal intubation/tracheostomy. Surgical repair is often complicated by additional malformation or severe comorbidities. This comprehensive review should give an overview on most common airway problems in neonates and children as well as available surgical techniques.

Pediatric airway surgery

Pediatric airway surgery is a challenging field in pediatric surgery. Laryngotracheal stenosis has a variety of congenital and acquired conditions that require precise assessment and tailored treatment for each individual patient. About 90% of acquired conditions are represented by subglottic stenosis (SGS) resulting as a complication of tracheal intubation. Congenital tracheal stenosis (CTS) is a rare and life-threatening malformation, usually associated with complete tracheal rings along a variable length of the trachea. Tracheomalacia (TM) is a process characterized by flaccidity of the supporting tracheal cartilage, widening of the posterior membranous wall, and reduced anterior-posterior airway caliber. The clinical presentation can vary from almost asymptomatic patients to near fatal airway obstruction. There is considerable variation in both the morphologic subtypes and the prognosis of pediatric airway. The patients are divided into three clinical groups (mild, moderate, and severe). A further division was proposed according to the presence or absence of associated anomalies. The definitive diagnosis of pediatric airway was made by means of rigid bronchoscope and computed tomography scan with three-dimensional reconstruction (3D-CT). Rigid bronchoscopy and 3D-CT confirmed the diagnosis in all the cases. Other associated anomalies include congenital heart disease, vascular anomalies, and BPFM (maldevelopment of aerodigestive tract). After definitive diagnosis of pediatric airway lesions, surgical intervention should be considered. Surgical strategy was presented on each lesion.

Diagnosis of subglottic stenosis in a rabbit model using long-range optical coherence tomography

OBJECTIVES/HYPOTHESIS

Current imaging modalities lack the necessary resolution to diagnose subglottic stenosis. The aim of this study was to use optical coherence tomography (OCT) to evaluate nascent subglottic mucosal injury and characterize mucosal thickness and structural changes using texture analysis in a simulated intubation rabbit model.

STUDY DESIGN

Prospective animal study in rabbits.

METHODS

Three-centimeter-long sections of endotracheal tubes (ETT) were endoscopically placed in the subglottis and proximal trachea of New Zealand White rabbits (n = 10) and secured via suture. OCT imaging and conventional endoscopic video was performed just prior to ETT segment placement (day 0), immediately after tube removal (day 7), and 1 week later (day 14). OCT images were analyzed for airway wall thickness and textural properties.

RESULTS

Endoscopy and histology of intubated rabbits showed a range of normal to edematous tissue, which correlated with OCT images. The mean airway mucosal wall thickness measured using OCT was 336.4 μm (day 0), 391.3 μm (day 7), and 420.4 μm (day 14), with significant differences between day 0 and day 14 (P = .002). Significance was found for correlation and homogeneity texture features across all time points (P < .05).

CONCLUSIONS

OCT is a minimally invasive endoscopic imaging modality capable of monitoring progression of subglottic mucosal injury. This study is the first to evaluate mucosal injury during simulated intubation using serial OCT imaging and texture analysis. OCT and texture analysis have the potential for early detection of subglottic mucosal injury, which could lead to better management of the neonatal airway and limit the progression to stenosis.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:64-69, 2017.

Incremental change in cross sectional area in small endotracheal tubes: A call for more size options

OBJECTIVE

To elucidate the relatively large incremental percent change (IPC) in cross sectional area (CSA) in currently available small endotracheal tubes (ETTs), and to make recommendation for lesser incremental change in CSA in these smaller ETTs, in order to minimize iatrogenic airway injury.

METHODS

The CSAs of a commercially available line of ETTs were calculated, and the IPC of the CSA between consecutive size ETTs was calculated and graphed. The average IPC in CSA with large ETTs was applied to calculate identical IPC in the CSA for a theoretical, smaller ETT series, and the dimensions of a new theoretical series of proposed small ETTs were defined.

RESULTS

The IPC of CSA in the larger (5.0-8.0 mm inner diameter (ID)) ETTs was 17.07%, and the IPC of CSA in the smaller ETTs (2.0-4.0 mm ID) is remarkably larger (38.08%). Applying the relatively smaller IPC of CSA from larger ETTs to a theoretical sequence of small ETTs, starting with the 2.5 mm ID ETT, suggests that intermediate sizes of small ETTs (ID 2.745 mm, 3.254 mm, and 3.859 mm) should exist.

CONCLUSION

We recommend manufacturers produce additional small ETT size options at the intuitive intermediate sizes of 2.75 mm, 3.25 mm, and 3.75 mm ID in order to improve airway management for infants and small children.

Airway damage of prematurity: The impact of prolonged intubation, ventilation, and chronic lung disease

Over the past four decades, advances in neonatal intensive care have led to the survival of smaller and more immature infants. The improved survival of very low birth weight infants is associated with long term respiratory morbidity, most frequently in the form of bronchopulmonary dysplasia. In this review, we will discuss the pathogenesis, risk factor as well as management of commonly seen acquired airway disorders associated with prematurity, prolonged intubation and ventilation.

Coblation-assisted management of pediatric airway stenosis

OBJECTIVES

The treatment of pediatric airway stenosis represents a major challenge for the otolaryngologist. The aim of this study is to evaluate the use of bipolar radiofrequency plasma ablation (Coblation) in the treatment of pediatric airway stenosis.

STUDY DESIGN

Retrospective case series. Tertiary care pediatric academic medical center.

METHODS

The medical records of 6 pediatric patients at Cohen Children's Medical Center from July 2009 to December 2015 were reviewed. All cases involved the use of radiofrequency plasma ablation to address airway stenosis. Patient presentation, surgical intervention(s), post-operative course and complications were analyzed.

RESULTS

All 6 cases involved pediatric airway stenosis, including glottic stenosis (2), bilateral vocal fold immobility (2), and intratracheal lesions (2). Coblation was used to perform a range of different procedures, including removal of scar/granulation tissue, partial arytenoidectomy, and posterior cordectomy. All patients experienced good results without major complications, perioperative, or post-operative sequellae.

CONCLUSION

The results of this study suggest that radiofrequency plasma ablation may be an effective endoscopic tool for the treatment of pediatric airway stenosis. Further study and more patients are required as this technique becomes increasingly applied.

Subglottic stenosis

Subglottic stenosis (SGS) is a congenital or acquired condition characterized by a narrowing of the upper airway extending from just below the vocal folds to the lower border of the cricoid cartilage. With the introduction of prolonged intubation in neonates (mid 1960s), acquired SGS became the most frequent cause of laryngeal stenosis; unlike congenital SGS, it does not improve with time. Laryngeal reconstruction surgery evolved as a consequence of the need to manage these otherwise healthy but tracheotomized children. Ongoing innovations in neonatal care have gradually led to the salvage of premature and medically fragile infants in whom laryngeal pathology is often more severe, and in whom stenosis often involves not only the subglottis, but also the supraglottis or glottis-causing significant morbidity and mortality. The primary objective of intervention in these children is decannulation or preventing the need for tracheotomy. The aim of this article is to present a more detailed description of both congenital and acquired SGS, highlighting the essentials of diagnostic assessment and familiarizing the reader with contemporary management approaches.

Long-Range Optical Coherence Tomography of the Neonatal Upper Airway for Early Diagnosis of Intubation-related Subglottic Injury

RATIONALE

Subglottic edema and acquired subglottic stenosis are potentially airway-compromising sequelae in neonates following endotracheal intubation. At present, no imaging modality is capable of in vivo diagnosis of subepithelial airway wall pathology as signs of intubation-related injury.

OBJECTIVES

To use Fourier domain long-range optical coherence tomography (LR-OCT) to acquire micrometer-resolution images of the airway wall of intubated neonates in a neonatal intensive care unit setting and to analyze images for histopathology and airway wall thickness.

METHODS

LR-OCT of the neonatal laryngotracheal airway was performed a total of 94 times on 72 subjects (age, 1-175 d; total intubation, 1-104 d). LR-OCT images of the airway wall were analyzed in MATLAB. Medical records were reviewed retrospectively for extubation outcome.

MEASUREMENTS AND MAIN RESULTS

Backward stepwise regression analysis demonstrated a statistically significant association between log(duration of intubation) and both laryngeal (P < 0.001; multiple r(2) = 0.44) and subglottic (P < 0.001; multiple r(2) = 0.55) airway wall thickness. Subjects with positive histopathology on LR-OCT images had a higher likelihood of extubation failure (odds ratio, 5.9; P = 0.007). Longer intubation time was found to be significantly associated with extubation failure.

CONCLUSIONS

LR-OCT allows for high-resolution evaluation and measurement of the airway wall in intubated neonates. Our data demonstrate a positive correlation between laryngeal and subglottic wall thickness and duration of intubation, suggestive of progressive soft tissue injury. LR-OCT may ultimately aid in the early diagnosis of postintubation subglottic injury and help reduce the incidences of failed extubation caused by subglottic edema or acquired subglottic stenosis in neonates. Clinical trial registered with www.clinicaltrials.gov (NCT 00544427).

The role of larygotracheal reconstruction in the management of recurrent croup in patients with subglottic stenosis

OBJECTIVES

To determine the role of laryngotracheal reconstruction for recurrent croup and evaluate surgical outcomes in this cohort of patients.

METHODS

Retrospective chart review at a tertiary care pediatric hospital.

RESULTS

Six patients who underwent laryngotracheal reconstruction (LTR) for recurrent croup with underlying subglottic stenosis were identified through a search of our IRB-approved airway database. At the time of diagnostic bronchoscopy, all 6 patients had grade 2 subglottic stenosis. All patients were treated for reflux and underwent esophageal biopsies at the time of diagnostic bronchoscopy; 1 patient had eosinophilic esophagitis which was treated. All patients had a history of at least 3 episodes of croup in a 1 year period requiring multiple hospital admissions. Average age at the time of LTR was 39 months (range 13-69); 5 patients underwent anterior graft only and 1 patient underwent anterior and posterior grafts. Patients were intubated for an average of 5 (range 3-8) days and hospitalized for an average of 12 (range 7-20) days post-operatively. One patient experienced narcotic withdrawal post-operatively, but there were no other post-operative complications. All patients underwent follow-up airway endoscopy within 4 weeks and none required any further dilation procedures. Average post-operative follow-up was 24 months (range 10-48) and none of the patients experienced any further episodes of croup.

CONCLUSIONS

Single stage LTR is a safe and effective treatment for recurrent croup in the setting of underlying subglottic stenosis, and should be considered in patients who are refractory to medical management.

The prevalence of airway problems in children with Down's syndrome

AIM

Airway disorders are common in children with Down's syndrome. We report the findings on airway endoscopy in a birth cohort of children from a well-defined geographical area, in order to estimate true population prevalence of airway problems in children with Down's syndrome.

METHOD

Retrospective case note review over a 20-year period between 1993 and 2013 for all children in Greater Glasgow born with Down's syndrome, identified through the hearing surveillance programme. All children undergoing airway endoscopy under general anaesthesia for investigation of potential airway symptoms (stridor, hoarseness, recurrent croup and difficulties with intubation/extubation) were studied in detail to identify the number with laryngeal, tracheal or bronchial pathology.

RESULTS

All 239 children (F:M=1.15:1) were reviewed. Of these, 39 (16.3%) underwent microlaryngoscopy-bronchoscopy under general anaesthesia for airway symptoms. The main presentations were stridor (9), extubation problems (12) and exacerbations of recurrent croup (7). Thirty-three were found to have at least one airway diagnosis (13.8%) including trachaeobronchomalacia (17), laryngeal cleft (2), laryngomalacia (2), tracheal compression (2), vocal cord paralysis (1), acquired tracheal stenosis (2) and symptomatic subglottic stenosis (14).

CONCLUSION

Laryngo-tracheo-bronchial pathology is much more common in children with Down's syndrome than in the general population, particularly subglottic stenosis and tracheal problems.

Ground zero: not asthma at all

Upper airway obstruction is commonly misdiagnosed as asthma. We report on four children with recurrent respiratory symptoms who had been erroneously diagnosed as having asthma and who received anti-asthma medication for several years. The evaluation of spirometry tracing was neglected in all cases. Subglottic stenosis, tracheomalacia secondary to tracheo-esophageal fistula, double aortic arch, and vocal cord dysfunction were suspected by direct inspection of the flow-volume curves and eventually diagnosed. The value of clinical history and careful evaluation of spirometry tracing in children with persistent respiratory symptoms is critically discussed.

Summarized institutional experience of paediatric airway surgery†

OBJECTIVES

The management of paediatric airway stenosis is complex, and requires a dedicated team, consisting of thoracic surgeons, phoniatricians, logopaedics, paediatricians and anaesthetists. The majority of paediatric laryngotracheal stenosis is a sequela of prematurity and prolonged post-partal intubation/tracheostomy. Surgical correction is often difficult due to a frequent combination of glottic and subglottic defects.

METHODS

In 2012, the Laryngotracheal Program Vienna was launched. Since then, 18 paediatric patients were surgically treated for (laryngo-)tracheal problems.

RESULTS

The median age of our patients was 26 months (range 2-180 months). Laryngotracheal stenosis extending up to the level of the vocal cords was evident in 9 patients. Three children were diagnosed with an isolated subglottic, and four with a short-segment tracheal stenosis or malacia. Two patients had a long-segment congenital malformation together with vascular ring anomalies. Five children were pretreated by rigid endoscopy before surgical correction, 12 of our 18 patients had a tracheostomy, 3 children were intubated at the time of operation. Different techniques of corrections were applied: laryngotracheal reconstruction (n = 4), extended partial cricotracheal resection (n = 4), cricotracheal resection with or without anterior split or dorsal mucosal flap (n = 4), slide tracheoplasty (n = 2), tracheal resection (n = 4). In 8 patients, a rib cartilage interposition was necessary in order to obtain a sufficient lumen enlargement and in 7 of these patients, an LT-Mold was placed to stabilize the reconstruction. We lost 2 patients, who were referred to our institution after failure of multiple preceding interventions, 2 and 3 months after the operation. Twelve patients are currently in an excellent condition, one is in an acceptable condition without a need for an intervention. Two patients required an endoscopic reintervention 18 and 33 months after the operation, 1 child is currently still cannulated.

CONCLUSIONS

Paediatric airway surgery is complex, and requires a dedicated interdisciplinary team. An armamentarium of different resection and reconstruction techniques is necessary in order to achieve good long-term results.

Long-range Fourier domain optical coherence tomography of the pediatric subglottis

BACKGROUND

Acquired subglottic stenosis (SGS) most commonly results from prolonged endotracheal intubation and is a diagnostic challenge in the intubated child. At present, no imaging modality allows for in vivo characterization of subglottic microanatomy to identify early signs of acquired SGS while the child remains intubated. Fourier domain optical coherence tomography (FD-OCT) is a minimally invasive, light-based imaging modality which provides high resolution, three dimensional (3D) cross-sectional images of biological tissue. We used long-range FD-OCT to image the subglottis in intubated pediatric patients undergoing minor head and neck surgical procedures in the operating room.

METHODS

A long-range FD-OCT system and rotary optical probes (1.2mm and 0.7mm outer diameters) were constructed. Forty-six pediatric patients (ages 2-16 years) undergoing minor upper airway surgery (e.g., tonsillectomy and adenoidectomy) were selected for intraoperative, trans-endotracheal tube FD-OCT of the subglottis. Images were analyzed for anatomical landmarks and subepithelial histology. Volumetric image sets were rendered into virtual 3D airway models in Mimics software.

RESULTS

FD-OCT was performed on 46 patients (ages 2-16 years) with no complications. Gross airway contour was visible on all 46 data sets. Twenty (43%) high-quality data sets clearly demonstrated airway anatomy (e.g., tracheal rings, cricoid and vocal folds) and layered microanatomy of the mucosa (e.g., epithelium, basement membrane and lamina propria). The remaining 26 data sets were discarded due to artifact, high signal-to-noise ratio or missing data. 3D airway models were allowed for user-controlled manipulation and multiplanar airway slicing (e.g., sagittal, coronal) for visualization of OCT data at multiple anatomic levels simultaneously.

CONCLUSIONS

Long-range FD-OCT produces high-resolution, 3D volumetric images of the pediatric subglottis. This technology offers a safe and practical means for in vivo evaluation of lower airway microanatomy in intubated pediatric patients. Ultimately, FD-OCT may be applied to serial monitoring of the neonatal subglottis in long-term intubated infants at risk for acquired SGS.

Comparison of Hybrid Laryngotracheal Reconstruction to Traditional Single- and Double-Stage Laryngotracheal Reconstruction

Objectives

(1) To describe outcomes from and modifications to the hybrid laryngotracheal reconstruction (LTR) technique and (2) to compare this technique to traditional single- and double-stage LTR (ssLTR/dsLTR).

Study Design

Chart review with case series.

Setting

Tertiary care otolaryngology specialty hospital.

Subjects

All patients under 18 years of age who underwent LTR by a single surgeon from July 1, 2009, to December 31, 2013.

Methods

Charts were assessed for age, gender, etiology of stenosis, type of reconstruction, comorbidities, length of stay, complications, and tracheostomy status. Analysis was performed using Kruskal-Wallis and Wilcoxon rank sum analysis.

Results

Forty-four patients were identified, with 13 hybrid LTRs, 27 ssLTRs, and 4 dsLTRs. Of the hybrid LTRs, an overall decannulation rate of 76.9% was noted, comparable to those for dsLTR. The hybrid LTR technique offered a significantly shorter period of narcotic use when compared to ssLTR (median 15 vs 21 days, P < .01). No patients in the hybrid LTR group developed supraglottic granulation tissue. There was no statistically significant difference in median length of stay for ssLTRs, dsLTRs, and hybrid LTRs ( P = .38).

Conclusion

The hybrid LTR technique is well tolerated and useful in patients of all ages. Narcotics can be weaned more quickly due to the presence of a secure airway at all times via the existing tracheostomy. Use of a long stent prevents formation of granulation tissue that may be seen with a suprastomal stent. This technique should be considered in patients with high-grade stenosis with a preexisting tracheostomy.

Gene therapy of c-myc suppressor FUSE-binding protein-interacting repressor by Sendai virus delivery prevents tracheal stenosis

Acquired tracheal stenosis remains a challenging problem for otolaryngologists. The objective of this study was to determine whether the Sendai virus (SeV)-mediated c-myc suppressor, a far upstream element (FUSE)-binding protein (FBP)-interacting repressor (FIR), modulates wound healing of the airway mucosa, and whether it prevents tracheal stenosis in an animal model of induced mucosal injury. A fusion gene-deleted, non-transmissible SeV vector encoding FIR (FIR-SeV/ΔF) was prepared. Rats with scraped airway mucosae were administered FIR-SeV/ΔF through the tracheostoma. The pathological changes in the airway mucosa and in the tracheal lumen were assessed five days after scraping. Untreated animals showed hyperplasia of the airway epithelium and a thickened submucosal layer with extensive fibrosis, angiogenesis, and collagen deposition causing lumen stenosis. By contrast, the administration of FIR-SeV/ΔF decreased the degree of tracheal stenosis (P < 0.05) and improved the survival rate (P < 0.05). Immunohistochemical staining showed that c-Myc expression was downregulated in the tracheal basal cells of the FIR-SeV/ΔF-treated animals, suggesting that c-myc was suppressed by FIR-SeV/ΔF in the regenerating airway epithelium of the injured tracheal mucosa. The airway-targeted gene therapy of the c-myc suppressor FIR, using a recombinant SeV vector, prevented tracheal stenosis in a rat model of airway mucosal injury.

Management experience of subglottic stenosis by endoscopic bougie dilatation with mitomycin C and review of literature: case series

The aim of the study was to examine and analyze the epidemiology and outcome of treatment for paediatric acquired subglottic stenosis treated with endoscopic bougie dilatation and topical mitomycin C. There were 15 patients identified from 2008 until 2013. All of them had acquired subglottic stenosis due to history of intubation. Majority of the patients had grade III stenosis, with the total of seven. Three patients had grade IV; three were grade II and two were grade I. All of the patients with severe stenosis (grade III and IV) needed tracheostomy while only one in mild stenosis group (grade I and II) required it for prolonged ventilation rather than obstruction due to subglottic stenosis. All of them underwent direct laryngoscopy under general anesthesia followed by endoscopic dilatation with bougie and topical mitomycin C 0.4 mg/ml for 5 min. Aim of success in our study was decannulation of tracheostomy or absence of symptoms at exertion. We achieved 6 (60 %) successful decannulation out of 10 patients with tracheostomy (excluded the patient with tracheostomy in grade I stenosis due to prolonged ventilation). As for those without tracheostomy, 3 (75 %) out of 4 patients were asymptomatic even at exertion. Average number of dilatation was 3.1 times, with mean duration of 28 min. No complications were reported in our series. One patient with grade I stenosis passed away due to severe pneumonia unrelated to the stenosis or dilatation, and she did not have any dilatation before she passed away. Multiple related risk factors were identified such as intubation, prematurity, movement of endotracheal tube, respiratory infection, traumatic intubation and gastroesophageal reflux disease. Experience of open surgical method was very limited in our centre in Sabah in East Malaysia. Endoscopic technique plays an important role in treatment of subglottic stenosis with adjunct like mitomycin C possibly booster the successful rate.

Characteristics and surgical outcome of 98 infants and children surgically treated for a laryngotracheal stenosis after endotracheal intubation: excellent outcome for higher grades of stenosis after SS-LTR

INTRODUCTION

To describe the characteristics and surgical outcome of 98 infants and children treated for an acquired laryngeal stenosis after intubation for respiratory support.

MATERIAL AND METHODS

We retrospectively reviewed our data from the last 18 years (1994-2013) concerning infants and children with an acquired laryngotracheal stenosis who were treated in our hospital with a laryngotracheal reconstruction or a cricotracheal resection. Outcome was defined by decannulation ratio.

RESULTS

Of the 98 infants and children who were studied, 54% were preterm, 18% neonates, 13% infants and 14% children. Ninety-one SS-LTR's, two DS-LTR's and five CTR's were performed as primary surgery; three revision operations were performed (DS-LTR). Seventy-seven children had a tracheostomy prior to surgery; decannulation ratio was 93% after primary surgery and 95% after inclusion of revision surgery. For SS-LTR, the decannulation ratio was 93%, including grade III stenosis with comorbidities. Male sex and glottic involvement of the stenosis are correlated to failure of decannulation. Intubation in the term neonatal period is correlated to complicated post-operative course after SS-LTR.

CONCLUSIONS

Excellent results of surgery for acquired laryngotracheal stenosis can be obtained with a high decannulation rate. Even for higher grades of stenosis with comorbidities and glottic involvement, an SS-LTR is an effective surgical treatment for acquired laryngeal stenosis.

Endolaryngeal dilatation versus laryngotracheal reconstruction in the primary management of subglottic stenosis

OBJECTIVES

The scope of the study is to compare endolaryngeal dilatations (ED) with laryngotracheal reconstruction with cartilage grafting (LTRCG) in terms of restenosis.

METHODS

Pediatric subglottic stenosis patients treated in Hacettepe University, between 2002 and 2012 were retrospectively evaluated. Patients who had ED or LTRCG as primary management were included in the study. EDs were grouped into bronchoscopic dilatation (BD), laser incision and balloon dilatation (LBD) and cold knife incision and balloon dilatation (CKBD). The groups were evaluated in terms of restenosis and decannulation rates.

RESULTS

There were 35 patients (9 females, 26 males; mean age 4.42). LTRCG was performed in 16 patients (9 anterior and 7 anterior and posterior grafts). EDs were performed in 19 patients with 6 CKBDs, 7 LBDs and 6 BDs. There were 3 grade II, 13 grade III cases in the LTRCG group while 4 grade I, 6 grade II, 8 grade 3 and 1 grade 4 in the ED group. Overall decannulation rate was 97% (34/35) in all patients. Restenosis was higher in the ED group (63.2%) than the LTRCG group (31.3%) with rates of CKBD 16.7% (1/6), LBD 71.4% (5/7) and BD 100% (6/6). Restenosis rates were found to be increasing with higher grades (grade I-25%, grade II-66%, grade III-85%).

CONCLUSION

ED may need more repetitive interventions than LTRCG due to restenosis. Less restenosis might be observed when balloon is used for dilatation and cold knife for mucosal incisions.

A general review of the otolaryngologic manifestations of Down Syndrome

OBJECTIVE

Down Syndrome (DS) is the most common chromosome abnormality in liveborn children. Otolaryngologists frequently encounter these patients in their practice; in one survey, 50% of DS patients had been seen by Otolaryngology at least once. As such, it is essential that the practicing Otolaryngologist is aware of the otologic, rhinologic, and laryngologic manifestations of this complex disease and comfortable in the management and treatment of these unique patients. Our goal was to provide this information in a concise and definitive document.

METHODS

A comprehensive literature review using PubMed was completed. The terms "Otolaryngology", "Head and neck", "Ear, nose, throat", "Down Syndrome", and "Trisomy 21" were searched in various combinations. Applicable articles that discussed the Otolaryngologic manifestations of Down Syndrome were included.

RESULTS

In total, fifty articles were included for review. The Down Syndrome child tends to have smaller external ear canals, have higher rates of chronic ear disease, and may present with conductive, sensorineural, or mixed hearing loss. As such, DS patients should receive behaviouralaudiological testing every 6 monthsand annually after the age of three in addition to closer follow-up by an Otolaryngologist if tympanic membranes cannot be visualized or if the external auditory canals are significantly stenosed. Management should involve close follow-up and a low threshold for PE tube placement to reduce the risks for speech and language delay. Chronic rhinitis in the Down Syndrome patient is common. Retrognathia, hypotonia, and macroglossia can all cause obstructive sleep apnea (OSA) in this population and therefore each DS patient should get an overnight polysomnograph. Subglottic stenosis, vocal cord paralysis and laryngomalacia are not infrequently seen in the Down Syndrome patient. To reduce acquired subglottic stenosis, endotracheal tubes that are at least two sizes smaller than what is appropriate for the patient's age should be used.

CONCLUSION

Down Syndrome is common and there are many Otolaryngologic manifestations. We recommend that this patient population visit an Otolaryngologist on a regular basis and that the practicing Otolaryngologist is comfortable with the management and treatment of the unique challenges faced with these children.

Long-term outcomes of balloon dilation for acquired subglottic stenosis in children

Objectives. Balloon dilation laryngoplasty has been suggested as an alternative treatment to open surgical treatment of acquired subglottic stenosis in children. We describe long-term outcomes of balloon dilation for acquired subglottic stenosis in children. Methods. The medical charts of children who had balloon dilation for subglottic stenosis secondary to intubation were reviewed. Data included demographics, relevant history and physical examination, diagnostic workup, and management. Outcomes of balloon dilation were assessed based on improvement in preoperative symptoms, grading of stenosis, complications, and need for additional procedures. Results. Three children (2 male, 1 female, age range: 14 weeks-1 year) underwent balloon dilation for acquired subglottic stenosis. Patients presented with stridor and increased work of breathing. Duration of intubation ranged from 2 days to 3 weeks. Patients became symptomatic 5 days to 6 weeks after extubation. Grade of subglottic stenosis was II in 2 patients and III in one. Subglottic stenosis patients had 2-3 dilations within 2-10 weeks. All patients were asymptomatic during 14-21-month follow-up. Conclusions. Serial balloon dilation was safe and successful method to manage acquired subglottic stenosis in this group of children. No recurrence was noted in a follow-up more than a year after resolution of symptoms.

Bacterial biofilms and increased bacterial counts are associated with airway stenosis

OBJECTIVES

Most airway stenoses are acquired secondary to the use of prolonged endotracheal intubation. Antibiotics have been shown to decrease local inflammation and granulation tissue formation in the trachea. However, antibiotic therapy is not 100% effective in preventing or treating granulation tissue formation. Development of bacterial biofilms may explain this finding. This study evaluates the difference between tracheal stenotic segments and normal trachea in terms of (1) presence of bacterial biofilms, (2) quantitative bacterial counts, and (3) inflammatory markers.

STUDY DESIGN

Cross-sectional study.

SETTING

Tertiary care academic medical center.

SUBJECTS

A total of 12 patients were included in the study. Tissue from stenotic segments from 6 patients with airway stenosis undergoing open airway procedures were compared with tracheal tissue from 6 patients without airway stenosis undergoing tracheostomy.

METHODS

Scanning electron microscopy for biofilm detection, quantitative polymerase chain reaction for quantitative analysis of bacterial count, and immunohistochemistry were performed for inflammatory markers transforming growth factor β1 (TGF-β1) and SMAD3.

RESULTS

Compared with the patients without airway stenosis, patients in the airway stenosis group showed presence of bacterial biofilms, a significantly higher expression of 16S rRNA gene copies per microgram of tissue (187.5 vs 7.33, P = .01), and higher expression of TGF-β1 (91% vs 8%, P < .001) and SMAD3 (83.5% vs 17.8%, P < .001).

CONCLUSION

Bacterial biofilms, increased bacterial counts, and higher expression of TGF-β1 and SMAD3 are associated with airway stenosis.

Demonstration of the role of an implantable bioscaffold in airway reconstruction: a pilot study utilizing an animal model

INTRODUCTION

Laryngotracheal reconstruction is a common procedure to repair subglottic stenosis. Despite a success rate upwards of 85%, this procedure has significant morbidity associated with it, specifically with the site of the graft harvest and recurrence of stenosis. We propose that a recently described cellular bioscaffold xenograft may be useful in reducing these complications.

METHODS AND MATERIALS

10 Sprague Dawley rats were divided into 2 groups of 5. One group underwent incision through the cricoid and the first two tracheal rings followed by primary closure (G1); the second group underwent incision through the cricoid and the first two tracheal rings followed by placement of the xenograft (G2); additionally, a specimen was harvested from an animal which did not undergo any surgical procedure to compare to the two surgical groups. Specimen harvest occurred on post-operative days 1, 7, 14, 21, and 28.

RESULTS

6 of 10 animals provided usable data. All animals receiving the xenograft survived until the time of specimen harvest. Only 1 animal undergoing primary closure survived beyond post-operative day one. On histology review, the xenograft animals showed a progressive decrease in fibrosis relative to the animals that underwent primary closure. On POD 28, restoration of the respiratory epithelium and intact basement membrane was noted in the xenograft group.

CONCLUSION

We believe that this pilot study shows the potential of utilizing bio-implantable biomaterials, specifically a cellular bioscaffold which encourages the ingrowth of native tissue instead of fibrosis. Histologic analysis shows that use of the xenograft can initiate the proliferation of native tissues decreasing the amount of fibrosis present post-operatively, although significant further analysis is needed before definitively concluding that this approach is superior to utilization of a graft.

Management of laryngotracheal stenosis in infants and children: the role of re-do surgery in cases of severe subglottic stenosis

Although many advances have improved the treatment of congenital and acquired laryngotracheal stenosis in children over the past two decades, the therapeutic decision-making process remains challenging for pediatric surgeons and otolaryngologists. Severe subglottic stenosis is a complex laryngeal injury that necessitates multiple airway procedures, and the approach depends on the exact nature of the cicatricial lesion and its effect on the vocal cord mobility. Therefore, it is imperative that the pediatric surgeons and otolaryngologists dealing with this situation should be well trained in endoscopy and laser treatment, in addition to open surgical intervention. Open re-do surgery remains the best choice in cases of severe congenital stenosis, glottic immobility, or after two to three endoscopic procedures have been performed without any significant improvement.

Pediatric tracheotomy: a 30-year experience

BACKGROUND/PURPOSE

The aim of this study was to investigate changes of pediatric tracheotomy practice over time.

METHODS

A retrospective analysis of all tracheotomies at the University Children's Hospital Zurich from January 1990 to December 2009 was performed. Data analyzed included the indication for tracheotomy, patient comorbidities, age, duration of cannulation, and complications. The second part of the study consisted of comparing our results with data from an earlier study done at the same institution by Simma et al. (Eur J Pediatr 1994;153:291-296) reviewing the patients with tracheotomies treated from 1979 to 1989.

RESULTS

Between 1990 and 2009, 119 patients were included. The indication for tracheotomy was airway obstruction in 70% and prolonged ventilation in 30%. 70% of the patients were operated on before 1 year of age. Serious postoperative complications occurred in 25 patients (23%). There was one death related to tracheotomy. Successful decannulation was achieved in 60%, on average 28 months after tracheotomy. The decannulation rate in patients with airway obstruction was 74% compared to 52% for the patients in prolonged ventilation group; a statistically significant difference was observed (p < 0.05). The longitudinal analysis showed an increase of indications for prolonged ventilation and a trend toward decreased tracheotomy complications.

CONCLUSION

Over 30 years, a shift in the indications of pediatric tracheotomy, with an increasing number of procedures performed for prolonged ventilation, was found. The tracheotomy-related mortality was under 1%. Tracheotomy remains a valid and safe option for pediatric patients. Level of evidence 2c.

Subglottic stenosis and socio-economic deprivation: a 6-year review of the Scottish National Service for Paediatric Complex Airway Reconstruction

OBJECTIVE

Subglottic stenosis is the third most common cause of stridor in children, and severe cases may need surgical reconstruction. Babies born to parents in high-deprivation areas are at increased risk of prematurity and low birth weight. This may require intensive care admission with prolonged intubation, hence, putting them at increased risk of subglottic stenosis. We aimed to review cases of subglottic stenosis requiring surgical intervention in the Scottish population and its association with socio-economic deprivation.

METHODS

We collected retrospective data on all children who underwent open reconstructive surgery for subglottic stenosis between January 2005 and January 2011 at the Royal Hospital for Sick Children, Yorkhill, which provides the national complex airway reconstruction service for Scotland. The Scottish Index of Multiple Deprivation (SIMD) was used to categorise deprivation based on the child's home postal code. Incidence figures were calculated based on the total number of births in each deprivation category over the time period.

RESULTS

There were a total of 53 cases of subglottic stenosis undergoing surgery in Scotland over the last 6 years, of which 31 were acquired and 22 were congenital. The most common procedure performed was laryngotracheal reconstruction with cartilage grafts (46 cases). No association was found between deprivation and the incidence of acquired or congenital subglottic stenosis.

CONCLUSION

Our data is the first attempt to review the incidence of subglottic stenosis in the Scottish population and its association with deprivation. Perhaps surprisingly, we found no association.

Primary dilatation as a treatment for pediatric laryngotracheal stenosis: a systematic review

OBJECTIVE

To identify and review original studies on balloon and rigid dilatation as primary therapy for laryngotracheal stenosis (LTS) in pediatric patients.

DESIGN

Systematic review.

METHODS

A comprehensive search strategy in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials was conducted and limited to human studies published in English after 1980. Two independent reviewers identified original studies on primary dilatation therapy for LTS in patients younger than 18 years. Studies on tracheobronchial stenosis or stents for tracheomalacia were excluded. 22 of 369 identified studies (6%) met the inclusion criteria. Two reviewers independently appraised the level of evidence of each study, using the Oxford clinical evidence-based medicine guidelines, and extracted raw data using a standardized form developed a priori.

RESULTS

The patient population consisted of grades I-III LTS. Most studies used adjuvant therapy including laser or topical agents. The primary outcome of success was achieving a functional airway without open laryngo-tracheal surgery or ongoing need for a tracheostomy. In studies using balloon dilatation alone (6 studies, n=10) or rigid dilatation alone (5 studies, n=68), success rates were 50% and 53%, respectively. Success rates ranged from 50% to 78% for balloon dilatation with adjuvant therapy (6 studies, n=24) and 53%-100% for rigid dilatation with adjuvant therapy (5 studies, n=61).

CONCLUSIONS

Dilatation was successful as primary therapy in the majority of low-grade pediatric LTS. Given the lack of comparative studies among other study limitations, it could not be determined whether one method of dilatation was superior to another.

Tracheostomy for infants requiring prolonged mechanical ventilation: 10 years' experience

BACKGROUND

Despite advances in care of critically ill neonates, extended mechanical ventilation and tracheostomy are sometimes required. Few studies focus on complications and clinical outcomes. Our aim was to provide long-term outcomes for a cohort of infants who required tracheostomy.

METHODS

This study is a retrospective review of 165 infants born between January 1, 2000 and December 31, 2010 who required tracheostomy and ventilator support. Children with complex congenital heart disease were excluded.

RESULTS

Median gestational age was 27 weeks (range 22-43), and birth weight was 820 g (range 360-4860). The number of male (53.9%) and female (46.1%) infants was similar (P = .312). Infants were divided into 2 groups based on birth weight ≤1000 g (A) and >1000 g (B). Group A: 87 (57.6%) infants; group B 64 (42.4%). Overall tracheostomy rate was 6.9% (87/1345) for group A versus 0.9% (64/6818) for B (P <.001). Group A had a longer time from intubation to positive pressure ventilation independence, 505 days (range 62-1287) vs 372 days (range 15-1270; P = .011). Infants who had >1 reason for tracheostomy comprised 78.8% of the sample; 69.1% of infants were discharged on ventilators. Birth weight did not affect time from tracheostomy to decannulation (P = .323). More group A infants were decannulated (P = .023). laryngotracheal reconstruction rate was 35.8%. Five-year survival was 89%. Group B had higher mortality (P = .033). 64.2% of infants had developmental delays; 74.2% had ≥2 comorbidities.

CONCLUSIONS

Tracheostomy rates were higher for extremely low birth weight infants than previously reported rates for all infants. Decannulation rates and laryngotracheal reconstruction rates were consistent with previous studies. Survival rates were high, but developmental delay and comorbidities were frequent.

Incidence of post-intubation subglottic stenosis in children: prospective study

Objective:

To evaluate the incidence of subglottic stenosis in children undergoing endotracheal intubation.

Methods:

Children in the paediatric intensive care unit of a tertiary care hospital were considered eligible for inclusion if they received endotracheal intubation for more than 24 hours. After extubation, children underwent flexible fibre-optic nasolaryngoscopy. Based on this first evaluation, they were divided into two groups: ‘acute normal’, with mild laryngeal alterations or normal findings; and ‘acute alterations’, with moderate to severe laryngeal alterations. Further laryngoscopic follow up (7–10 days later) was undertaken for those children in the acute normal group who developed symptoms during follow up (after discharge from the intensive care unit), and for all children in the acute alterations group. Children were then classified into two final groups: ‘normal final examination’, with no chronic changes; and ‘subglottic stenosis’.

Results:

We included 123 children. The incidence of subglottic stenosis was 11.38 per cent (95 per cent confidence interval, 6.63–17.94 per cent). All the children who developed subglottic stenosis had had moderate to severe alterations immediately after extubation.

Conclusion:

This incidence of subglottic stenosis is quite high and needs further investigation to identify risk factors.

Cyclooxygenase-2 inhibition for the prevention of subglottic stenosis

OBJECTIVE

To evaluate the role of targeted cyclooxygenase-2 inhibition in reducing scarring associated with a subglottic airway mucosal injury.

DESIGN

Thirty-four New Zealand white rabbits underwent anterior cricothyroidotomy. Subglottic stenosis (SGS) was created by carbon dioxide laser injury.

INTERVENTION

Treatment consisted of intraperitoneal injection of celecoxib or vehicle for 4 days. Endoscopies were performed to assess injury and healing. Subglottic mucosal secretions were collected with Gelfoam swabs (Pfizer Inc) before and after injury and at subsequent time points. Animals were humanely killed at 3 or 8 weeks after injury and airways were excised, followed by gross examination and histologic analysis to assess the severity of SGS. Secretions were analyzed for interleukin-1β, prostaglandin E2 (PGE2), and matrix metalloproteinase-8 by enzyme-linked immunosorbent assays.

RESULTS

Endoscopy showed mild to moderate stenosis in the celecoxib group, but mild to severe stenosis in the vehicle group. Histologic assessment confirmed and quantified reduction in stenosis and scarring as well as advanced reepithelialization. In the healing tissue, mucosal thickening (stenosis) was reduced significantly (P = .02) in celecoxib-treated animals compared with those treated with vehicle, at 3 and 8 weeks (decrease in thickness by 32% and 49%, respectively). Collagen density (fibrosis) was also reduced 25% at both 3 and 8 weeks but the difference was not statistically significant (P = .20). Reduced level of PGE2 in the subglottic mucosal secretions was correlated with mucosal thickness at 8 weeks (P = .02).

CONCLUSION

Short-duration, anti-inflammatory therapy resulted in reduced stenosis and fibrosis with correlation of PGE2 levels in subglottic mucosal secretions.

Subglottic injury: a clinically relevant animal model

OBJECTIVES/HYPOTHESIS

To develop a clinically aligned, reproducible model for subglottic injury.

STUDY DESIGN

Prospective randomized control pilot study.

METHODS

Juvenile (3-month-old) New Zealand White rabbits underwent intubation with a 3-cm length of an endotracheal tube that was chosen so that there would be no air leak below 20 cm of water. This tube was one or two sizes above the appropriate tube for the animal. It was held in situ with a suture placed at the trachea and secured over a button in the neck for a period of 1 week. Animals were sacrificed 1 week postextubation, and larynges were harvested. A range of histological techniques and gross morphology were utilized to examine the injury caused at the level of the subglottis. Unintubated animals constituted controlled specimens.

RESULTS

Intubated animals demonstrated considerable histopathology including evidence of ulceration, inflammation, granulation tissue, perichondritis, and chondritis when compared with control animals. Morphometric analysis demonstrated a significant increase in lamina propria thickness (P = .0013), mucosal thickness (P ≤ .0001), and in goblet cell areal density (P = .014). Analysis of mucin types found a significant decrease in acidic (P = .0001) mucin coinciding with a significant increase in mixed mucin types (P = .0013).

CONCLUSIONS

Our model provides a reliable and reproducible technique for acute/subacute injury to the subglottis secondary to intubation, which is consistent with previous histological findings of early changes associated with acquired subglottic stenosis (SGS). Future uses of this model could include the examination of current adjunctive therapies and their effects on limiting progression to SGS.

Laryngotracheal reconstruction in infants and children: are single-stage anterior and posterior grafts a reliable intervention at all pediatric hospitals?

OBJECTIVE

To review outcomes of pediatric laryngotracheal stenosis treated by single-stage laryngotracheal reconstruction with anterior and posterior cartilage grafts and compare decannulation rate for single-stage laryngotracheal reconstruction with rates published at larger (>200 beds) pediatric tertiary care hospitals.

METHODS

A 4-year retrospective chart review (2004-2008) of all patients undergoing procedures coded with 2008 CPT codes 31582 (laryngoplasty for laryngeal stenosis with graft or core mold, including tracheotomy) and 31587 (laryngoplasty, cricoid split) for a pediatric, tertiary-care hospital. Interventions were single-stage laryngotracheal reconstruction with anterior and posterior cartilage grafts, and the main outcome measure was the decannulation rate after single-stage laryngotracheal reconstruction.

RESULTS

We identified 44 patients with subglottic stenosis, of whom 13 underwent single-stage laryngotracheal reconstruction with anterior and posterior cartilage grafts. The mean age at surgery was 2.2 years (range, 5 months to 4 years). Twelve of 13 children had Cotton-Myer grade III stenosis. Ninety-two percent (12 of 13) of children remain decannulated. The mean follow up was 52 months.

CONCLUSIONS

Single-stage laryngotracheal reconstruction with anterior and posterior cartilage grafts appears to be a safe and effective technique for managing patients with high-grade subglottic stenosis at intermediate size children's hospitals. Our overall decannulation rate of 92% compares favorably to that reported in the literature (84-96%).

Endoscopic anterior cricoid split with balloon dilation in infants with failed extubation

Subglottic injury (SGI) is a known complication of prolonged intubation in neonates and infants and can lead to failed extubation. SGI is a spectrum that includes mucosal edema, ulceration, granulation perichondritis, and mature scar formation. Although medical management aimed at treating mucosal edema and extraesophageal reflux is successful in treating a majority of patients, some require surgical intervention to successfully achieve extubation. The surgical options for these patients include tracheostomy, open anterior cricoid split (ACS), and laryngotracheal reconstruction with cartilage grafting. Open ACS is performed through an external incision requiring placement of a drain for a few days. Extubation success rates in the 70% to 80% range have been widely reported. In this article we describe an endoscopic technique for ACS, in which after an endoscopic airway assessment confirms isolated SGI, the cricoid cartilage is divided transluminally with cold steel. Balloon dilation (BD) is then performed with an appropriately sized angiography balloon. We describe preliminary results in which two of three patients were successfully extubated after endoscopic ACS with BD. We believe that this novel technique is a promising alternative to open ACS with similar indications. In addition to the avoidance of a skin incision, endoscopic ACS with BD may enable extubation with comparably shorter lengths of postprocedure intubation than open ACS. Larger series will be required to further establish outcomes of this procedure, including success and complication rates.