Subglottic stenosis

Degrees of Inflammation in the Treatment of Subglottic Stenosis in a Rabbit Model: Histopathological Assessment of a Novel Bioabsorbable Ultra-high Ductility Magnesium Alloy Stent

OBJECTIVE

Utilizing a novel histopathological scoring system and subglottic stenosis (SGS) rabbit model, we aimed to compare degrees of inflammation and severity of narrowing in the subglottis between two minimally invasive therapeutic modalities: endoscopic balloon dilation (EBD) alone versus EBD with placement of a bioabsorbable ultra-high ductility magnesium (UHD-Mg) alloy stent.

METHODS

SGS was induced endoscopically via microsuspension laryngoscopy in 23 New Zealand white rabbits. The control group (n = 11) underwent EBD alone, the study arm (n = 12) underwent EBD with implantation of bioabsorbable UHD-Mg alloy stents. Rabbits were euthanized at 2-, 3-, and 6-weeks after SGS induction, coinciding with wound healing stages. Using Optical Coherence Tomography (OCT), cross-sectional areas of airways were compared to calculate the mean percentage of intraluminal area at sequential time points. A novel histopathological scoring system was used to analyze frozen sections of laryngotracheal complexes. The degree of inflammation was quantified by scoring changes in inflammatory cell infiltration, epithelial ulceration/metaplasia, subepithelial edema/fibrosis, and capillary number/dilation. Univariate analysis was utilized to analyze these markers.

RESULTS

We found rabbits implanted with the bioabsorbable UHD-Mg alloy stent had statistically significantly higher scores in categories of hyperplastic change (stents vs controls: 1.48 vs 0.46 p < 0.001), squamous metaplasia (22 vs 5 p < 0.001), and neutrophils/fibrin in lumen (31 vs 8, p < 0.001). Rabbits who received EBD alone had higher scores of subepithelial edema and fibrosis (2.70 vs 3.49, p < 0.0256). The stented rabbits demonstrated significantly increased mean percent stenosis by intraluminal mean area compared to controls at 2 weeks (88.56 vs 58.98, p = 0.032), however at all other time points there was no significant difference between intraluminal subglottic stenosis by mean percent stenosis area.

DISCUSSION

Rabbits with SGS treated with UHD-Mg alloy stents demonstrated histopathologic findings suggestive of lower levels of tracheal fibrosis. This could indicate a reduced tendency towards the development of stenosis when compared to EBD alone. There was not a difference in luminal size between stent and non-stented rabbits at the six-week end point. Histologically, however, overall the use of bioabsorbable UHD-Mg alloy stenting elicited a greater tissue response at the level of the superficial mucosa rather than fibrosis of the lamina propria seen in the stented rabbits. This suggests more favorable healing and less of a tendency towards fibrosis and stenosis even though there may not be a benefit from a luminal size standpoint during this early healing period. Compared to known complications of currently available non-bioabsorbable metal or silicone-based stents, this proof-of-concept investigation highlights the potential use of a novel biodegradable UHD-Mg stent as a therapeutic modality for pediatric SGS.

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.

Management of pediatric choanal atresia restenosis and subglottic stenosis using steroid-eluting stents

OBJECTIVES

To depict the novel use of steroid-eluting stents in the treatment of choanal atresia (CA) restenosis and subglottic stenosis (SGS).

METHODS

A retrospective chart review of three pediatric patients, one with CA and two with SGS, treated with mometasone furoate eluting mini stents (PROPEL) was performed. Patients were evaluated for restenosis and adverse events between one to twelve months postoperatively.

RESULTS

Postoperatively, patient one with CA showed no signs of restenosis and required no further intervention. Patient two with SGS demonstrated an open subglottic lumen with no signs of restenosis as well as improved phonation following his planned serial procedures. Post-operatively, patient three with SGS exhibited no restenosis of the subglottic lumen, tolerated intermittent tracheostomy capping, and demonstrated improved phonation.

CONCLUSION

In this case series, we outline successful treatments for the management of CA restenosis and SGS with mometasone furoate-eluting stents. To our knowledge, this is the first reported application of this treatment in pediatric patients with CA restenosis and the second reported application in pediatric patients with SGS.

Bibliometric and visualized analysis of scientific publications on subglottic stenosis based on web of science core collection

BACKGROUND

Subglottic Stenosis (SGS), with increasing numbers of studies, is the most specific and common clinical type of Laryngotracheal Stenosis (LTS). There is rapid publication turnover with newer management introduced and expanding research field. To our knowledge, there is no bibliometric analysis of SGS yet.

METHODS

In August 2022, we performed a thorough search in the Web of Science Core Collection database using the word "subglottic stenosis," and "SGS." The 580 articles were arranged based on correlation. The collected articles were then analyzed with an assessment of relevant factors. Meanwhile, we analyzed the top 100 most-cited articles on SGS.

RESULTS

The frequency of publication on SGS has increased substantially over time. The USA has contributed the most articles (n = 301). Vanderbilt University published most of the articles among other institutions (n = 18). Laryngoscope topped the list of journals and has published 89 SGS-related articles. Research hotspots shift from surgical treatment to conservative management.

CONCLUSIONS

The SGS-related literature has grown rapidly in recent years. This study represents the first bibliometric analysis of scientific articles on SGS. Areas to improve in SGS research can be identified after this analysis of the most impactful articles on this topic.

Anesthesia for laryngotracheal reconstruction in children: A narrative review

Laryngotracheal stenosis, congenital or acquired, is a common cause of pediatric airway obstruction. Acquired subglottic stenosis frequently results from prolonged neonatal intubation. The clinical presentation of subglottic stenosis is variable, ranging from biphasic stridor and frequent upper respiratory infections to acute airway compromise. Optimal patient care requires clinical coordination within a multidisciplinary subspecialty team. Medical management includes optimizing respiratory status, gastroesophageal reflux, speech, feeding, nutrition therapies, and providing psychosocial support. If surgical intervention is required, the otolaryngologist, anesthesiologist, and perioperative team must collaborate closely to ensure successful operative outcomes. This narrative review of laryngotracheal stenosis will discuss the pathophysiology, clinical evaluation, medical management, and surgical interventions, and focus on the perioperative anesthetic considerations for children undergoing laryngotracheal reconstruction.

Congenital Malformations of the Cricoid Cartilage: Upper Airway Obstruction and Treatment Strategy

OBJECTIVES

To review treatment and outcomes in patients with congenital cricoid cartilage malformation.

METHODS

Retrospective analysis of patients with diagnosis of congenital cricoid malformation (CCM) treated in a single tertiary pediatric referral center between 1985 and 2022. Patients were grouped according to the morphology of the cricoid cartilage that was diagnosed during endoscopy. We reviewed the treatment strategy(s), decannulation rate, complications, and functional outcomes.

RESULTS

Twenty-nine patients were grouped into four morphological subtypes of cricoid cartilage: 10 patients had a hypoplastic cricoid, eight had an elliptic shape, five had severe anterior thickening, and six an accentuated V-shape posterior cricoid plate. Twenty-four patients underwent surgery, and five were closely followed up without surgical treatment. Eight patients had a tracheostomy prior to surgery, and the majority had a hypoplastic cricoid. Most patients (20 out of 24) required additional procedures postoperatively to achieve an age-appropriate airway. Thirteen patients needed endoscopic dilatation(s) and granulation tissue removal; four needed more aggressive treatment, and three patients required revision open surgery. Decannulation was achieved after a median of 4.5 months in all previously tracheostomized patients. Endoscopy at the last follow-up showed an age-appropriate airway in 27 patients; 20 patients had normal oral feeding, and 11 patients had a normal voice.

CONCLUSION

Endoscopy is important to diagnose CCM and most of the time patients would need only watchful waiting. In this report, surgery was required for patients who continued to remain symptomatic and had a compromised airway. The type of surgery depends on the type of cricoid malformation and the grade of stenosis.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:3185-3191, 2023.

Amelioration of Subglottic Stenosis by Antimicrobial Peptide Eluting Endotracheal Tubes

Introduction

Pediatric subglottic stenosis (SGS) results from prolonged intubation where scar tissue leads to airway narrowing that requires invasive surgery. We have recently discovered that modulating the laryngotracheal microbiome can prevent SGS. Herein, we show how our patent-pending antimicrobial peptide-eluting endotracheal tube (AMP-ET) effectively modulates the local airway microbiota resulting in reduced inflammation and stenosis resolution.

Materials and Methods

We fabricated mouse-sized ETs coated with a polymeric AMP-eluting layer, quantified AMP release over 10 days, and validated bactericidal activity for both planktonic and biofilm-resident bacteria against Staphylococcus aureus and Pseudomonas aeruginosa. Ex vivo testing: we inserted AMP-ETs and ET controls into excised laryngotracheal complexes (LTCs) of C57BL/6 mice and assessed biofilm formation after 24 h. In vivo testing: AMP-ETs and ET controls were inserted in sham or SGS-induced LTCs, which were then implanted subcutaneously in receptor mice, and assessed for immune response and SGS severity after 7 days.

Results

We achieved reproducible, linear AMP release at 1.16 µg/day resulting in strong bacterial inhibition in vitro and ex vivo. In vivo, SGS-induced LTCs exhibited a thickened scar tissue typical of stenosis, while the use of AMP-ETs abrogated stenosis. Notably, SGS airways exhibited high infiltration of T cells and macrophages, which was reversed with AMP-ET treatment. This suggests that by modulating the microbiome, AMP-ETs reduce macrophage activation and antigen specific T cell responses resolving stenosis progression.

Conclusion

We developed an AMP-ET platform that reduces T cell and macrophage responses and reduces SGS in vivo via airway microbiome modulation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-023-00769-9.

Complications during mechanical ventilation-A pediatric intensive care perspective

Mechanical ventilation is a common procedure performed in pediatric intensive care units, with over 20% of patients requiring invasive ventilator support. The most common indication for endotracheal intubation and ventilation in the pediatric population is respiratory failure either due to respiratory embarrassment or neurologic pathology. Despite the use of ventilation modes that are lung protective in the pediatric population, complications of mechanical ventilation occur frequently. These include atelectasis, post-extubation stridor, perioral tissue damage, ventilator associated pneumonia, mucus plugging, pneumothorax, pneumomediastinum, and ICU neuromyopathy. The purpose of this review is to discuss the risk factors, presentation and management of complications associated with mechanical ventilation in the pediatric population.

Open paediatric laryngotracheal reconstruction: a five-year experience at a tertiary referral centre

OBJECTIVE

Laryngotracheal reconstruction with costal cartilage graft is a cornerstone procedure in treatment of multiple paediatric airway pathologies. The current study aimed to report on the experience of laryngotracheal reconstruction and document post-operative outcomes and complications.

METHOD

Records of laryngotracheal reconstruction procedures performed between 2016 and 2020 were retrospectively reviewed. Primary indication, clinical data, decannulation rate, voice assessment, need for revision surgery and possible complications were analysed.

RESULTS

A total of 41 patients were treated with laryngotracheal reconstruction. Subglottic stenosis formed the largest percentage of cases followed by congenital glottic web (20 and 14 patients, respectively). Three patients (7.3 per cent) underwent single stage surgery, and the remaining cases had a double stage procedure. Revision laryngotracheal reconstruction was needed in a single case, and 38 out of 39 tracheostomised patients were successfully decannulated.

CONCLUSION

Favourable outcomes were reported with costal cartilage laryngotracheal reconstruction as a definitive treatment for a large range of paediatric airway problems.

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.

[Surgical treatment of postintubation stenosis of the larynx in children]

Post-intubation laryngeal stenosis is the most common cause of upper respiratory obstruction in children. According to published data, the incidence of post-intubation stenosis ranges from 0.1 to 20%. Treatment of children with chronic laryngeal stenosis is a special branch of respiratory surgery. It remains one of the most complex and urgent problems in pediatrics, pediatric otorhinolaryngology, and pediatric surgery. Although numerous studies have described various methods for treating stenosis of the infraglottic space, there is no standard management approach. Currently, there are two main treatment methods: endoscopic interventions and open reconstructive surgery. Each method has its benefits and drawbacks. Despite the use of various techniques, the effectiveness of cicatricial laryngeal stenosis repair and decannulation in children is 63-64%, according to published data. With combined lesions of infraglottic and vocal cord parts of the larynx, especially with their cicatricial obliteration, reconstructive surgery is successful only in 50% of cases. Thus, treating children with post-intubation respiratory stenosis remains a complex problem and is a relevant direction for further research.

Anesthesia management of pediatric subglottic stenosis: A case report

Subglottic stenosis balloon dilation in selected patients may be an option for the treatment of acquired subglottic stenosis, reducing the need for open surgical approaches or tracheostomy. This treatment is a major challenge to otolaryngologists and anesthesiologists, with an interactive collaboration being critical throughout the procedure. When performed, it is fundamental that otolaryngologists and anesthesiologists communicate properly during the procedure to achieve acceptable results. The complex management of the airway and inherent delicacy and risks of the intervention may be challenging. A proper preparation of the procedure and familiarization with the step-by-step technique could optimize the results and prepare the team to deal with intervening complications. We report a case of management and treatment of an 8-month-old baby with subglottic stenosis proposed for endoscopic balloon dilation treatment from Porto, North of Portugal.

The Effect of Subglottic Steroid injection on Blood Glucose in a Cohort of Patients With Subglottic Stenosis

OBJECTIVE

The objective of this work was to assess the effect of a single intralesional subglottic steroid injection on fasting blood glucose over 7 days in a cohort of patients with subglottic stenosis.

METHODS

A prospective cohort study of patients undergoing intralesional steroid injections at a tertiary academic center. Patients had baseline bloodwork performed, including fasting blood glucose (FBG), and hemoglobin A1C levels. Demographic data and risk factors were collected. Fasting capillary glucose (FCG) was measured using a capillary glucometer and performed by patients daily from days 0 to 7 after a single injection of Triamcinolone into the subglottic airway. Data were analyzed using descriptive and comparative statistics.

RESULTS

Eleven patients were enrolled, and 10 completed data collection over 7 days. All were female, with a mean age of 52.6 years (SD 17.5). Two patients were diabetic (non-insulin dependent). There was a statistically significant increase in FCG on day 1 post-injection (mean = 122.4 mg/dl compared to 100.7 mg/dl) that normalized for all patients within 24-72 h. The mean increase in FCG was 21.5% (SD 22.5%) of the initial value for the cohort. The diabetic group had statistically significant higher glucose values on day 1 compared to the non-diabetic group (146.5 mg/dl compared to 117.0 mg/dl).

CONCLUSION

A single subglottic steroid injection appears to cause a transient increase in FCG 1 day post injection, which resolves after 24-72 h and can be more pronounced in diabetic patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Treatment of Childhood High-Grade Subglottic Stenosis (SGS) Through Laryngotracheoplasty (LTP) in a Tertiary Pediatric Center from 2013 to 2020

Laryngotracheal reconstruction is the most common and effective treatment in childhood subglottic stenosis (SGS). Our aim is to review the success rate of laryngotracheoplasty (LTP) in pediatric high grade SGS cases in our tertiary center. The retrospective review was conducted on children with high grade subglottic stenosis who had undergone laryngotracheoplasty over a 7-year period (2013-2020) in tertiary pediatric care. A total of 20 patients who had history of high grade SGS during the stipulated period were included. All of them had undergone LTP. Decannulation was considered the primary outcome measure of success. Surveillance bronchoscopy was performed one year post airway reconstruction to detect residual stenosis. From January 2013 to December 2020, 20 patients aged between 1 and 16 years old underwent LTP. Among them, 10 patients (50%) had Grade III SGS while 5 had Grade III SGS with glottis stenosis (25%). The remaining 5 (25%) had severe Grade IV stenosis. Decannulation was achieved in 14 patients overall (70%) including 1 with revision. These 14 patients who achieved decannulation included 7 out of the 10 patients (70%) with Grade III, 2 out of the 5 (40%) patients with Grade III with glottic involvement, and 4 out of the 5 patients (80%) with Grade IV SGS. Fifteen (80%) patients had double stage LTP while 5 patients had single stage LTP. The study suggests that LTP is a promising approach in the treatment of Complex SGS. Furthermore, pediatric SGS, which is inherently complicated, can be treated with LTP effectively.

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.

The surgical treatment of acquired subglottic stenosis in children with double-stage laryngotracheal reconstruction

OBJECTIVES

The aim of this study is to report our experience with double-stage laryngotracheal reconstruction with anterior or antero-posterior cartilage grafting in the management of acquired laryngotracheal stenosis in children. Patients were treated by the same surgeon at the UMC National Research Center for Maternal and Child Health of Astana (Kazakhstan), and Sfendiyarov Kazakh National Medical University, Almaty (Kazakhstan).

METHODS

From November 2011 to September 2019, 9 children underwent surgery for grade III and IV laryngotracheal stenosis according to the European Laryngological Society classification (mean age of 6 years, range of 2-12 years).

RESULTS

Six patients underwent double-stage laryngotracheal reconstruction with anterior and posterior cartilage graft, and 3 patients underwent double-stage laryngotracheal reconstruction with single anterior cartilage graft. In all patients, a T-tube was used to stabilize the airway (mean time of 5.8 months, range of 5-9 months). One patient required additional dilation with bougies to obtain a viable laryngotracheal diameter. No postoperative complications were observed. One patient experienced recurrence of the stenosis 5 months after double-stage laryngotracheal reconstruction with double anterior and posterior cartilage grafts and is waiting for revision surgery. After a mean follow-up of 14 months (range of 4-36 months), 8 patients are tracheostomy-free, and all patients are feeding tube-free.

CONCLUSIONS

Double-stage laryngotracheal reconstruction with a single or double cartilage grafting represents a safe and effective option in the management of complete or severe laryngotracheal stenosis.

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.

The effect of varying degrees of stenosis on transition to turbulence in oscillatory flows

Many complications in physiology are associated with a deviation in flow in arteries due to a stenosis. The presence of stenosis may transition the flow to weak turbulence. The degree of stenosis as well as its configuration whether symmetric or non-symmetric to the parent artery influences whether the flow would stay laminar or transition to turbulence. Plenty of research efforts focus on investigating the role of varying degrees of stenosis in the onset of turbulence under steady and pulsatile flow conditions. None of the studies, however, have focused on investigating this under oscillatory flow conditions as flow reversal is a major occurrence in a number of physiologic flows, and is of particular relevance in cerebrospinal fluid flow research. Following up on the previous work in which a \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$75\%$$\end{document}75% stenosis was studied, this contribution is a detailed investigation of the role of degrees of stenosis on transition in an oscillatory flow. A cylindrical pipe with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$25\%$$\end{document}25%, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$50\%$$\end{document}50% and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$60\%$$\end{document}60% reductions in area in axisymmetric and eccentric configurations is studied for transition with 3 different pulsation frequencies of a purely oscillatory flow. Cycle averaged Reynolds numbers between 1800 and 2100 in steps of 100 are studied for each configuration resulting in 72 simulations each conducted on 76,800 CPU cores of a modern supercomputer. It is found that a higher degree of stenosis and eccentricity causes earlier transition to turbulence in oscillatory flow. The results further demonstrate that a higher frequency of oscillation results in larger hydrodynamic instability in the flow, which is more prominent in smaller degrees of stenosis.

Respiratory problems and associated factors following endoscopic balloon dilatation procedure in children with acquired subglottic stenosıs

OBJECTIVES

Endoscopic balloon dilatation (EBD) offers a safe and non-invasive surgical option for the treatment of subglottic stenosis. Patient selection is important to achieve good results and to detect which patients are more prone to the development of complications. The aim of this study was to determine predictors of postoperative problems and early complications in primary EBD surgeries.

METHODS

A retrospective analysis was made of patients with acquired subglottic stenosis who were operated on with the EBD technique between January 2010 and December 2019 in the Otolaryngology-Head and Neck Surgery Department of Baskent University Hospital. Demographic data including the age and sex of the patients were collected together with etiology, presence of chromosomal or craniofacial anomaly (C/CA), duration of prolonged intubation (DPI), and extubation dilatation timeframe (EDT). Intra and postoperative follow-up data were recorded of the need for intubation or tracheotomy, development of desaturation, and grade and type of stenosis.

RESULTS

The male to female ratio was 2:1. The patients comprised 42 males and 22 females with a mean age of 296.52 ± 551.93 days. The cause of prolonged intubation was surgery for congenital heart disease in 50 (78.1%) patients and prematurity in 14 (21.9%). The type of lesion was acute granulation in 44 (72.1%) and chronic granulation in 17 (27.9%) patients. C/CA was determined in 13 patients, the mean grade of stenosis was 76.33 ± 15.21%, mean DPI was 25.25 ± 35.49 days, and mean EDT was calculated as 78.23 ± 373.82 days. Desaturation following endoscopic balloon dilatation developed in 26 (40.6%), orotracheal intubation was required in 10 (15.6%), tracheotomy in 10 (15.6%), and cardiopulmonary arrest occurred in 4 (6.25%). Prematurity, a longer duration of preoperative intubation, longer time from extubation to dilatation, older age, and higher grade of stenosis were determined as factors associated with postoperative early respiratory complications.

CONCLUSION

EBD indication should be carefully considered in children with acquired subglottic stenosis. To achieve better results and minimise complications, EBD should be performed without delay.

Post-intubation tracheal stenosis in pediatric age group: single-center experiences of 24 years

BACKGROUND AND AIM

Post-intubation tracheal stenosis (PITS) is an iatrogenic injury that involves some patients. Given the importance of this issue and the referral of a significant number of children with tracheal stenosis to Masih Daneshvari Hospital in Tehran, Iran, the present study investigated tracheal stenosis following prolonged intubation in the pediatric age group.

METHODS

In this observational retrospective study, from 1994 to 2018, the medical records of all children under 14 years of age with a history of PITS were reviewed. Demographic and clinical characteristics including signs and symptoms, the underlying condition that leads to intubation, duration of intubation, type of stenosis, and the therapeutic approach, type of surgery, and follow-up were collected and analyzed using SPSS.

RESULTS

Among 161 patients with a mean age of 9.8 ± 4.2 years, 69% were male. The site of stenosis was limited to the trachea in 47% and others both trachea and subglottic area were involved. The most common cause of intubation was trauma. The most common symptoms were dyspnea and wheezing. Success rates of reconstruction were 93.75% in type I, 82.15% in type II, and 35.70% in type III. Among the 16 patients who underwent Type III surgery, decannulation was not performed in 11 patients. Traction in the anastomosis and complications were stated in 26 and 10% of the patients respectively, a mortality rate of 8.7% was also reported.

CONCLUSION

In the case of endotracheal intubation, PITS should be considered in the differential diagnosis of dyspnea in children as well as adults.

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.

Case Report: A Rare Cause of Stridor and Hoarseness in Infants-Congenital Laryngeal Web

BACKGROUND

Congenital laryngeal web is a rare disease that can cause stridor, dyspnea, hoarseness, and other symptoms. Children with this disease generally have stridor, weak crying, and hoarseness at birth, but these symptoms can also occur during the days, weeks, months, and even years after birth. Respiratory tract infection will obviously aggravate these manifestations, and recovery is slow after symptomatic treatment. Neck CT and laryngoscopy can detect and diagnose this disease. It is important that the disease can be considered and examined in infants with recurrent stridor and persistent hoarseness after birth.

CASE SUMMARY

We report a 23-month-old boy who was admitted to hospital due to stridor and hoarseness after birth. Combined with the results of laryngoscopy, he was diagnosed with congenital laryngeal web, and was treated with carbon dioxide (CO₂) laser and cryotherapy by bronchoscope. The prognosis was good.

CONCLUSION

Congenital laryngeal web is a rare but challenging laryngeal lesion. It is very important that the disease can be considered and examined for infants with recurrent stridor and persistent hoarseness after birth. The treatment strategy after diagnosis should be determined according to the classification of laryngeal web and the severity of children's symptoms.

Prognostic factors in the management of pediatric subglottic stenosis

OBJECTIVE

We report outcomes of endoscopic interventions in the management of pediatric subglottic stenosis (SGS), and factors that lead to open airway reconstruction.

METHODS

A retrospective cohort review of all pediatric patients with SGS, treated by a single surgeon, at a tertiary academic medical center from 2012 to 2020 was conducted. Variables recorded included patient demographics, initial grade of stenosis, gestational age, length of intubation, comorbidities as well as total number of interventions.

RESULTS

A total of 47 patients were included in the study, of which 51% (n = 24) were female. Laryngotracheal reconstruction (LTR) was performed in 49% (n = 23) of patients. Decannulation was achieved in 25 of 32 tracheostomized patients. Fifteen patients did not have tracheostomy. There was a significant difference in gestational age (28.7 ± 5.36 vs 33.2 ± 6.13), initial grade of stenosis (2.3 ± 0.82 vs 1.6 ± 0.88), and total number of interventions (5.7 ± 2.8 vs 2.3 ± 1.5) when stratifying patients proceeding to LTR versus not (p < 0.05). There was no significant difference, however, in the length of intubation between the two groups. Of the comorbidities recorded, none were found to have a significant impact on the outcome.

CONCLUSION

Subglottic stenosis is a challenging condition to treat, often requiring multiple interventions including LTR. We propose a set of risk factors that may assist in the treatment of SGS patients with certain comorbidities to minimize interventions and maximize outcomes.

Readmission and reoperation after laryngeal dilation in children: NSQIP-P analysis

OBJECTIVE

To identify specific comorbidities and their relationship to complications in children who underwent laryngeal dilation, specifically comparing children with tracheostomy versus no tracheostomy as well as differences in outcomes between age groups.

METHODS

Retrospective study analyzing data collected in the American College of Surgeons National Surgical Improvement - Pediatric Database (2015-2018). Patients were selected using Current Procedural Terminology code 31528. Variables analyzed include demographics, comorbidities, readmission, reoperation, reintubation and total length of stay.

RESULTS

982 cases were identified. Comorbidities significantly higher (p < .001) in age group 1 (Age ≤ 1 year, N = 245) versus age groups 2 (Age >1 but ≤ 3 years, N = 151) and 3 (Age > 3 years, N = 270) include premature birth, ventilator dependent, oxygen support, cardiac risk factors, steroid use, nutritional support, and hematologic disorders. Comorbidities significantly higher (p < .001) in children without a tracheostomy include premature birth, history of asthma, bronchopulmonary dysplasia/chronic lung disease, oxygen support, structural pulmonary/airway abnormality, esophageal/gastric/intestinal disease, history of previous cardiac surgery, developmental delay/impaired cognitive status, cerebral palsy, neuromuscular disorder, steroid use, and nutritional support. Younger children were significantly more likely (p < .001) to require reintubation and remain in the hospital longer. Children without a tracheostomy were significantly more likely (p < .001) to return to the operating room and remain in the hospital longer.

CONCLUSION

Younger children and those without a tracheostomy are more likely to have adverse outcomes after laryngeal dilation. Awareness of these associations and outcomes is helpful in establishing benchmarks for outcomes in this group.

Drug-Eluting Endotracheal Tubes for Preventing Bacterial Inflammation in Subglottic Stenosis

OBJECTIVES/HYPOTHESIS

Subglottic stenosis (SGS) results from dysregulated extracellular matrix deposition by laryngotracheal fibroblasts causing scar tissue formation following intubation. Recent work has highlighted a relationship between this inflammatory state and imbalances in the upper airway microbiome. Herein, we engineer novel drug-eluting endotracheal (ET) tubes to deliver a model antimicrobial peptide Lasioglossin-III (Lasio) for the local modulation of the microbiome during intubation.

STUDY DESIGN

Controlled in vitro study.

METHODS

ET tubes were coated with a water-in-oil (w/o) emulsion of Lasio in poly(d,l-lactide-co-glycolide) (PLGA) by dipping thrice. Peptide release was quantified over 2 weeks via fluorometric peptide assays. The antibacterial activity was tested against airway microbes (Staphylococcus epidermidis, Streptococcus pneumoniae, and pooled human microbiome samples) by placing Lasio/PLGA-coated tubes and appropriate controls in 48 well plates with diluted bacteria. Bacterial inhibition and tube adhesion were tested by measuring optical density and colony formation after tube culture, respectively. Biocompatibility was tested against laryngotracheal fibroblasts and lung epithelial cells.

RESULTS

We achieved a homogeneous coating of ET tubes with Lasio in a PLGA matrix that yields a prolonged, linear release over 1 week (typical timeframe before the ET tube is changed). We observed significant antibacterial activity against S. epidermidis, S. pneumoniae, and human microbiome samples, and prevention of bacterial adherence to the tube. Additionally, the released Lasio did not cause any cytotoxicity toward laryngotracheal fibroblasts or lung epithelial cells in vitro.

CONCLUSION

Overall, we demonstrate the design of an effective-eluting ET tube to modulate upper-airway bacterial infections during intubation which could be deployed to help prevent SGS.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Asphyxia caused by delayed subglottic stenosis after neck trauma

Delayed subglottic stenosis (SGS) is an unusual complication. Here, we report a particular case of delayed SGS. A 17-year-old female suffered extensive injuries including severe neck trauma in a car accident, and complained of dyspnea after 30 days. Tracheal stenosis was observed by fiber optic bronchoscopy, but no specific treatment was administered to the patient. While being transferred to a tertiary hospital 3 days later, the patient fell into deep coma due to hypoxia, and died of hypoxic-ischemic encephalopathy and severe pulmonary infection in the intensive care unit (ICU) 58 days later. Postmortem autopsy and pathological investigation revealed tracheal stenosis 3.0 cm below the vocal cords with a diameter of 0.5 cm, which was caused by a cricoid cartilage fracture, fibrous tissue proliferation and inflammatory cell infiltration. We believed that external forces caused the cricoid fracture and mucosal damage, and after a month of fibrous repair, scar tissue formed the stenosis and caused her death. This report describes a rare condition in which slowly progressive intralaryngeal stenosis formation after external neck trauma could cause asphyxial death in a previously asymptomatic adult.

Decreasing tracheostomy placement in hospitalized pediatric patients with subglottic stenosis - Kids' Inpatient Database (KID) analysis

OBJECTIVES

We aimed to assess procedural trends for tracheostomy placement in the management of children with subglottic stenosis. We hypothesize that with increased use of less invasive airway interventions for subglottic stenosis, tracheostomy may be performed less frequently over time.

METHODS

Data were collected from the Kids' Inpatient Database (KID) for pediatric discharges with an admission diagnosis of subglottic stenosis (Stenosis of larynx: ICD-9 code 478.74) from across the United States for years 2000, 2003, 2006, 2009, and 2012. The number of overall procedures and specific airway procedures including tracheostomy (ICD-9-CM codes 31.1, 31.29) were evaluated.

RESULTS

A weighted estimate of 18,124 pediatric discharges with a diagnosis of subglottic stenosis were identified. Overall, there was an increase in the mean number of procedures performed during hospitalization from 2000 to 2012 (p < 0.001); however, there was a decrease in the proportion of children undergoing tracheostomy placement (p < 0.001).

CONCLUSIONS

Trends over the past decade from a US national database have revealed decreasing tracheostomy placement in hospitalized pediatric patients with subglottic stenosis. This may be due to a change in paradigm with increased use of less invasive, possibly endoscopic, treatment in this patient population. Further investigations may be helpful to identify management paradigms to optimize care in order to help avoid tracheostomy placement.

Drug delivery to the pediatric upper airway

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

Use of Airway Ultrasound in Infants With Unexpected Subglottic Stenosis During Anesthesia Induction: A Case Report

Point-of-care ultrasound has been integrated into airway management because it allows for rapid and noninvasive assessments. We present 2 cases of unexpected subglottic stenosis in infants during induction of anesthesia. Intubation failed even with endotracheal tubes that were small for patients' age. Airway ultrasound was used to measure the subglottic airway diameters, which were 2.0 and 3.0 mm in first and second cases, respectively. The severity of subglottic stenosis in the first case was grade III, requiring emergent tracheostomy. In conclusion, airway ultrasound helps to assess possibility of intubation and plan further airway management in children with unexpected difficult airway.

Histological features of complete tracheal rings in congenital tracheal stenosis

PURPOSE

Congenital tracheal stenosis is a disease in which complete tracheal cartilage rings (CTCR) cause airway narrowing. Although tracheal cartilage malformation has been suggested as a cause of CTCR, no histological studies have been performed. Here, we report a comparison of the tissues from CTCR and normal tracheal cartilage.

METHODS

Thirty-one infants who underwent slide tracheoplasty at our institution from May 2016 to August 2019 were included. Tissues from ten autopsy cases without tracheal lesions were used as controls. The survey items were tracheal cartilage cell density, cartilage thickness, and chondrocyte findings.

RESULTS

The median cartilage cell density from cases was 23/125 × 125 µm² and from controls was 23.5/125 × 125 µm² (p = 0.90). The median cartilage thickness from cases was 689 µm and from controls was 840 µm (p = 0.11). Comparing the ventral and dorsal sides of the CTCR tissues, the cell density was significantly different (median ventral 23/125 × 125 µm²; median dorsal 19.5/125 × 125 µm²; p = 0.034). There were no significant findings in the chondrocytes of the CTCR tissues.

CONCLUSION

CTCR tissues did not differ in cartilage density and thickness from normal tracheal cartilage.

Structure and Function of the Vocal Cords after Airway Reconstruction on Magnetic Resonance Imaging

Objectives/Hypothesis

Dysphonia is a common problem at long‐term follow‐up after airway surgery for laryngotracheal stenosis (LTS) with major impact on quality of life. Dysphonia after LTS can be caused by scar tissue from initial stenosis along with anatomical alterations after surgery. There is need for a modality to noninvasively image structure and function of the reconstructed upper airways including the vocal cords to assess voice outcome and possible treatment after LTS. Our objective was to correlate vocal cord structure and function of patients after airway reconstruction for LTS on static and dynamic magnetic resonance imaging (MRI) to voice outcome.

Study Design

Prospective cohort study.

Methods

Voice outcome was assessed by voice questionnaires ((pediatric) Voice Handicap Index (p)VHI)) and the Dysphonia Severity Index (DSI). Postsurgical anatomy, airway lumen, and vocal cord thickness and movement on multiplanar static high‐resolution MRI and dynamic acquisitions during phonation was correlated to voice outcome.

Results

Forty‐eight patients (age 14.4 (range 7.5–30.7) years) and 11 healthy volunteers (15.9 (8.2–28.8) years) were included. Static MRI demonstrated vocal cord thickening in 80.9% of patients, correlated to a decrease in DSI (expected odds 0.75 [C.I. 0.58–0.96] P = .02). Dynamic MRI showed impaired vocal cord adduction during phonation in 61.7% of patients, associated with a lower DSI score (0.65 [C.I. 0.48–0.88] P = .006).

Conclusions

In LTS patients, after airway reconstruction MRI can safely provide excellent structural and functional detail of the vocal cords correlating to DSI, with further usefulness expected from technical refinements. We therefore suggest MRI as a tool for extensive imaging during LTS follow‐up.

Level of evidence

3 Laryngoscope, 131:E2402–E2408, 2021

Treatment of complex laryngotracheal stenosis in childhood–experience of a tertiary University Hospital from 2016 to 2019

Background

Laryngotracheal stenosis is a major cause of airway obstruction in pediatric age. The correction of such abnormality still remains a challenge, both because of anatomical issues in childhood and also due to the difficulty in having properly trained professionals and adequate hospital facilities. As treatment, many different surgical techniques are offered ranging from endoscopic and less invasive procedures to open surgeries, such as laryngotracheal reconstruction and cricotracheal resection. The treatment for complex laryngotracheal stenosis is considered successful when we have decannulation or resolution of respiratory failure with release from intensive care unit. Eighteen patients who were monitored at the pediatric otorhinolaryngology service between 2016 and 2019 were diagnosed with complex stenosis, with the collection of demographic data, comorbidities, degree of initial stenosis, post-treatment aspect, and whether or not decannulation occurred.

Results

Of the eighteen cases, three had congenital stenosis, fourteen had acquired stenosis, and one had mixed stenosis. Ages ranged from 4 months old to 15 years old. Six (33.3%) underwent endoscopic dilation procedures only, six (33.3%) underwent laryngotracheoplasty, and five (27.7%) cricotracheal resections. One patient underwent a slide tracheoplasty. Seven patients (38.8%) had to undergo more than one type of procedure to improve stenosis. Out of the eighteen patients, three of them were never tracheostomized. Of the remaining fifteen patients, fourteen (93.3%) were decannulated.

Conclusions

The success rate in decannulation or the resolution of respiratory failure with discharge from the ICU, after the procedures for correcting stenosis in childhood in our service, was 94.4%.

In-vivo efficacy of biodegradable ultrahigh ductility Mg-Li-Zn alloy tracheal stents for pediatric airway obstruction

Pediatric laryngotracheal stenosis is a complex congenital or acquired airway injury that may manifest into a potentially life-threatening airway emergency condition. Depending on the severity of obstruction, treatment often requires a combination of endoscopic techniques, open surgical repair, intraluminal stenting, or tracheostomy. A balloon expandable biodegradable airway stent maintaining patency while safely degrading over time may address the complications and morbidity issues of existing treatments providing a less invasive and more effective management technique. Previous studies have focused on implementation of degradable polymeric scaffolds associated with potentially life-threatening pitfalls. The feasibility of an ultra-high ductility magnesium-alloy based biodegradable airway stents was demonstrated for the first time. The stents were highly corrosion resistant under in vitro flow environments, while safely degrading in vivo without affecting growth of the rabbit airway. The metallic matrix and degradation products were well tolerated by the airway tissue without exhibiting any noticeable local or systemic toxicity.

Endoscopic management of pediatric extubation failure in the intensive care unit

OBJECTIVES

This study investigated the endoscopic findings associated with pediatric extubation failure (EF) and evaluated the prognosis of endoscopic procedures.

METHODS

We retrospectively reviewed the data of children with EF in the intensive care unit from January 1, 2013 to December 31, 2019. Fifty-one children receiving endoscopic examination were enrolled in this study. EF was defined as the need for reintubation within 72 h of the first attempted extubation.

RESULTS

Thirty-three children (65%) were successfully extubated after endoscopic procedures, and 18 children (35%) failed in extubation. There was a higher percentage of children transferred from other hospitals with intubation in the failure group (56% vs 12%, p = 0.002). Subglottic stenosis (SGS) (35%) and laryngeal and tracheal granulation (33%) were two of the most common findings. Fourteen patients (82%) with granulation were successfully extubated. Two children in the failure group were diagnosed with mitochondrial myopathies (chrM:3243) and congenital myasthenic syndrome (CHAT). The success rate in cases of SGS reached 83% (15/18). Five patients diagnosed with laryngomalacia and another 3 patients with tracheomalacia failed extubation after supraglottoplasty and needed a temporary tracheostomy.

CONCLUSION

Granulation and subglottic stenosis were the leading causes of extubation failure. Patients transferred with intubation might have a poor prognosis after endoscopic procedures. Neuromuscular and metabolic disorders could be a hidden reason for extubation failure.

Etiological profile of upper airway obstruction in infants

Background

Respiratory distress is recognized as any sign of breathing difficulty in infants. Some congenital anomalies present immediately with airway distress, while others are asymptomatic or discovered later in infancy or childhood. Our objectives are to detect different laryngeal causes of respiratory distress in infants and to measure the relative risk of some variables like age, sex, family history, and other congenital anomalies for developing laryngeal causes of respiratory distress. This observational cross-sectional study was carried out during the period from June 2017 to December 2018 at Children’s University Hospital. The study included 80 infants who presented with respiratory distress and admitted to the hospital. All patients subjected to a detailed history from their parents and full general and ENT examinations. X-ray, MSCT neck or direct laryngoscope were carried out in selected cases.

Results

As regard age, 58% of cases were between 1–6 months, 28% of cases between 6 months and 1 year, and 14% between 1–2 years. Laryngeal causes of respiratory distress among infants were distributed as follow: 70% laryngomalacia, 18% subglottic stenosis, 8% laryngeal web, and 4% of cases were caused by vocal fold paralysis (VFP). The laryngeal causes of respiratory distress did not reveal any statistically significant difference among different age groups or between both genders (P = 0.257, 0.286; respectively). Also, there was no statistically significant difference between infants with positive family history and those without as regard the laryngeal causes of respiratory distress (P = .378).

Conclusion

The majority of respiratory distress cases (58%) were between 1–6 months. Bivariant analysis of variables age, sex, family history, and other congenital anomalies showed that they were not potent risk factors for developing laryngomalacia, subglottic stenosis, laryngeal web, and vocal fold paralysis. Laryngomalacia represented the commonest cause of respiratory distress (70%) followed by subglottic stenosis (18%), then laryngeal web (8%), and finally the vocal fold paralysis represented the least percentage (4%). Apart from laryngomalacia, the percentages of other causes seem to vary according to sample size and geographic area of study. So, being familiar with the common causes of respiratory distress in a given region is very essential in order not to miss a potentially life-threatening diagnosis.

MRI of the upper airways in children and young adults: the MUSIC study

RATIONALE

Paediatric laryngotracheal stenosis (LTS) is often successfully corrected with open airway surgery. However, respiratory and vocal sequelae frequently remain. Clinical care and surgical interventions could be improved with better understanding of these sequelae.

OBJECTIVE

The objective of this cross-sectional study was to develop an upper airway MRI protocol to obtain information on anatomical and functional sequelae post-LTS repair.

METHODS

Forty-eight patients (age 14.4 (range 7.5-30.7) years) and 11 healthy volunteers (15.9 (8.2-28.8) years) were included. Spirometry and static and dynamic upper airway MRI (3.0 T, 30 min protocol) were conducted. Analysis included assessment of postoperative anatomy and airway lumen measurements during static and dynamic (inspiration and phonation) acquisitions.

MAIN RESULTS

Good image quality without artefacts was achieved for static and dynamic images in the majority of MRIs. MRI showed vocal cord thickening in 80.9% of patients and compared with volunteers, a significant decrease in vocal cord lumen area (22.0 (IQR 17.7-30.3) mm² vs 35.1 (21.2-54.7) mm², p=0.03) but not cricoid lumen area (62.3±27.0 mm² vs 66.2±34.8 mm², p=0.70). Furthermore, 53.2% of patients had an A-frame deformation at site of previous tracheal cannula, showing lumen collapse during inspiration. Dynamic imaging showed incomplete vocal cord abduction during inspiration in 42.6% and incomplete adduction during phonation in 61.7% of patients.

CONCLUSIONS

Static and dynamic MRI is an excellent modality to non-invasively image anatomy, tissue characteristics and vocal cord dynamics of the upper airways. MRI-derived knowledge on postsurgical LTS sequelae might be used to improve surgery.

Aetiopathogenesis of Laryngotracheal Stenosis: A Retrospective Review

Background. Airway stenosis is a technically challenging pathology to deal with. Various aetiologies can lead to the stenosis; however, trauma, mostly related to intubation, is the commonest so far. This study retrospectively evaluates various aetiological factors resulting in airway stenosis and the associated patient-related factors. Objectives. The objectives of this study were to evaluate the common patient-related factors, aetiology, site, and mode of presentation of airway stenosis and to evaluate the duration of intubation resulting in airway stenosis. Materials and methods. This was a retrospective study carried out at the Department of ENT-HNS, Institute of Medicine, Nepal. Record files from January 2014 to January 2019 of all cases with endoscopic diagnosis of airway stenosis were evaluated. Demographic data, site, severity, aetiology, time, and mode of presentation were noted. The severity of stenosis was graded based on Cotton–Meyer (CM) classification. Results. A total of 33 cases were included in the study. The trachea and the subglottis were the frequent sites to be involved. Intubation-related trauma was the commonest aetiology with a shortest duration of intubation of only 4 days resulting in development of the stenosis. The other aetiologies were congenital, trauma, inflammation, and idiopathic. Conclusion. Trauma, mostly related to intubation, is still the commonest cause for the development of airway stenosis. Along with the duration of intubation, there are several other factors that can affect the development of stenosis. A prospective study with a large population is required to draw a definite conclusion.

Hybrid Knife, a Novel Drug Delivery Tool for Treatment of Tracheal Stenosis: A Case Report

The treatment of subglottic stenosis remains a challenge due to anatomic and technological limitations, and there is no consensus regarding treatment. Restenosis and granulation formation are the most common complications. Balloon dilatation combined with cryotherapy and adjuvant topical medication is one treatment method. However, the efficacy of adjuvant topical medication is controversial, and the lack of efficacy may be related to the effective dose of the drug delivered to the submucosal layer of the lesion. Therefore, a tool with high efficiency for delivering medications to the submucosal layer via injection may play an important role in treatment. A hybrid knife (HK) with a pressure water jet traditionally used in endoscopy submucosal dissection to inject saline into the submucosa was employed here to inject medications for subglottic stenosis, followed by electrical excision. Here, we report the case of a man with complex subglottic stenosis who underwent balloon dilatation combined with cryotherapy and an adjuvant submucosal triamcinolone injection performed with an HK. The drug was delivered more efficiently into the submucosal layer, and the lumen of the trachea was patent. Performing a submucosal injection with an HK may be a new approach to deliver medications to the submucosal layer for the treatment of tracheal stenosis.

A Longitudinal Analysis of Outcomes in Tracheostomy Placement Among Preterm Infants

OBJECTIVES

To study a case series of preterm and extremely preterm infants, comparing their decannulation and survival rates after tracheostomy.

METHODS

We performed a single-institution longitudinal study of preterm infants with a tracheostomy. Infants were categorized as premature (born > 28 weeks and < 37 weeks) and extremely premature (born ≤ 28 weeks). Decannulation and survival rates were determined using the Kaplan-Meier method. Neurocognitive quality of life (QOL) was reported as normal, mild/moderately, and severely impaired. Statistical significance was set at P < .05.

RESULTS

This study included 240 patients. Of those, 111 were premature and 129 were extremely preterm. The median age (interquartile range) at tracheostomy was 4.8 months (0.4). Premature infants were more likely than extremely preterm to have airway obstruction (54% vs. 32%, P < .001); whereas extremely preterm infants were more likely to have bronchopulmonary dysplasia (68% vs. 15%, P < .001) and to be ventilation-dependent (68% vs. 54%, P < .001). The 5-year decannulation rate for premature infants was 46% and for extremely preterm was 64%. The 5-year survival rate post-tracheostomy for preterm was 79% and for extremely preterm was 73%. The log-rank test of equality showed that decannulation and survival were similar (P > .05) for both groups, even after controlling for potentially confounding factors like race, age, gender, birth weight, and age at tracheostomy. For neurocognitive QOL, 47% of patients survived with severely impaired QOL after tracheostomy. Preterm had 56% with severely impaired QOL and extremely preterm had 40% with severely impaired QOL (P = .03).

CONCLUSION

This study demonstrated that the time to decannulation and the likelihood of survival did not vary among premature and extremely premature infants even when controlling for other confounding variables.

LEVEL OF EVIDENCE

3b Laryngoscope, 131:417-422, 2021.

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.

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.

An Adolescent With Progressive Shortness of Breath

Shortness of breath and wheezing are common presenting signs for children in the emergency department. In adolescence, it is often due to asthma or lower respiratory tract infections. We present a rare pediatric case of an adolescent with biphasic stridor and progressive exercise-induced shortness of breath who was found to have severe idiopathic subglottic stenosis.

Post-intubation subglottic stenosis in children: Analysis of clinical features and risk factors

BACKGROUND

Subglottic stenosis (SGS) is a complication that develops after intubation and is characterized by respiratory distress. The aim was to evaluate patients with post-intubation SGS and to discover the factors contributing to its development.

METHODS

A total of 112 patients who had a history of intubation were included. The case group consisted of 50 patients with post-extubation persistent respiratory symptoms for which flexible bronchoscopy (FOB) was conducted and showed SGS. The control group consisted of 62 patient with no post-extubation persistent respiratory symptoms, for whom FOB was not done (n = 54), and who had post-extubation persistent respiratory symptoms and underwent FOB, which did not show subglottic stenosis (n = 8).

RESULTS

No significant differences were detected related to age, gender, and gestational age. The median number of recurrent intubations was 2.5 and 3 in the case group and in control group, respectively (P = 0.14). The median duration of intubation was 20.5 days in the case group, and 6 days in the control group (P < 0.001). The Myer-Cotton classification indicated a degree of obstruction of grade 1 (mild) in 30% (n = 15), grade 2 in 16% (n = 8), grade 3 in 48% (n = 24), and grade 4 in 6% (n = 3) of the case group.

CONCLUSION

The duration of intubation was found to be a significant risk factor for SGS development. Age at intubation, gender, gestational age, indication of intubation, and the number of recurrent intubations were found to have no significant association. Patients with post-extubation persistent respiratory problems, especially those with prolonged intubations, should be evaluated for SGS.