A Clinical-Grade Partially Decellularized Matrix for Tracheal Replacement: Validation In Vitro and In Vivo in a Porcine Model.

The management of extensive tracheal resection followed by circumferential replacement remains a surgical challenge. Numerous techniques are proposed with mixed results. Partial decellularization of the trachea with the removal of the mucosal and submucosal cells is a promising method, reducing immunogenicity while preserving the biomechanical properties of the final matrix. Despite many research protocols and proofs of concept, no standardized clinical grade protocol is described. Furthermore, local and systemic biointegration mechanisms of decellularized trachea are not well known. Therefore, in a translational research perspective, this work set up a partial tracheal decellularization protocol in line with Cell and Tissue Products regulations. Extensive characterization of the final product is performed in vitro and in vivo. The results show that the Partially Decellularized Trachea (PDT) is cell-free in the mucosa and submucosa, while the cartilage structure is preserved, maintaining the biomechanical properties of the trachea. When implanted in the muscle in vivo for 28 days, no systemic inflammation is observed, and locally, the PDT shows an excellent biointegration and vascularization. No signs of graft rejection are observed. These encouraging results confirmed the efficacy of the clinical grade PDT production protocol, which is an important step for future clinical applications.

Full circumferential human tracheal replacement: a systematic review.

Full Circumferential Tracheal Replacement (FCTR) is a surgical challenge, indicated in rare cases of extensive tracheal resection, with no consensus on surgical technique or materials. A systematic review according to PRISMA guidelines was carried out from 2000 to 2022 to identify cases of FCTR, to compare surgical indications, the nature of the tracheal substitutes and their immunological characteristics, surgical replacement techniques and vascularization. Thirty-seven patients, including five children, underwent FCTR surgery using 4 different techniques: thyrotracheal complex allograft (n = 2), aorta (n = 12), autologous surgical reconstruction (n = 19), tissue-engineered decellularized trachea (n = 4). The mean follow-up was 4 years. Of the 15 deceased patients, 10 died of the progression of the initial pathology. For the majority of the teams, particular care was given to the vascularization of the substitute, in order to guarantee long-term biointegration. This included either direct vascularization via vascular anastomosis, or an indirect technique involving envelopment of the avascular substitute in a richly vascularized tissue. Stent placement was standard, except for autologous surgical reconstructions where tracheal caliber was stable. Internal stents were frequently complicated by granulation and stenosis. Although epithelial coverage is essential to limit endoluminal proliferation and act as a barrier, fully functional ciliated airway epithelium did not seem to be necessary. In order to facilitate future comparisons, a standardized clinical trial, respecting regulatory constraints, including routine follow-up with tracheal biomechanics assessment and scheduled biopsies could be proposed. It would help collecting information such as dynamics and mechanisms of tracheal bio-integration and regeneration.

International pediatric otolaryngology group (IPOG) consensus on approach to aspiration.

OBJECTIVE: To provide recommendations for a comprehensive management approach for infants and children presenting with symptoms or signs of aspiration. METHODS: Three rounds of surveys were sent to authors from 23 institutions worldwide. The threshold for the critical level of agreement among respondents was set at 80 %. To develop the definition of "intractable aspiration," each author was first asked to define the condition. Second, each author was asked to complete a 5-point Likert scale to specify the level of agreement with the definition derived in the first step. RESULTS: Recommendations by the authors regarding the clinical presentation, diagnostic considerations, and medical and surgical management options for aspiration in children. CONCLUSION: Approach to pediatric aspiration is best achieved by implementing a multidisciplinary approach with a comprehensive investigation strategy and different treatment options.

Development and qualification of clinical grade decellularized and cryopreserved human esophagi.

Tissue engineering is a promising alternative to current full thickness circumferential esophageal replacement methods. The aim of our study was to develop a clinical grade Decellularized Human Esophagus (DHE) for future clinical applications. After decontamination, human esophagi from deceased donors were placed in a bioreactor and decellularized with sodium dodecyl sulfate (SDS) and ethylendiaminetetraacetic acid (EDTA) for 3 days. The esophagi were then rinsed in sterile water and SDS was eliminated by filtration on an activated charcoal cartridge for 3 days. DNA was removed by a 3-hour incubation with DNase. A cryopreservation protocol was evaluated at the end of the process to create a DHE cryobank. The decellularization was efficient as no cells and nuclei were observed in the DHE. Sterility of the esophagi was obtained at the end of the process. The general structure of the DHE was preserved according to immunohistochemical and scanning electron microscopy images. SDS was efficiently removed, confirmed by a colorimetric dosage, lack of cytotoxicity on Balb/3T3 cells and mesenchymal stromal cell long term culture. Furthermore, DHE did not induce lymphocyte proliferation in-vitro. The cryopreservation protocol was safe and did not affect the tissue, preserving the biomechanical properties of the DHE. Our decellularization protocol allowed to develop the first clinical grade human decellularized and cryopreserved esophagus.

Endothelial CD34 expression and regulation of immune cell response in-vitro.

Endothelial cells cover the lining of different blood vessels and lymph nodes, and have major functions including the transport of blood, vessel homeostasis, inflammatory responses, control of transendothelial migration of circulating cells into the tissues, and formation of new blood vessels. Therefore, understanding these cells is of major interest. The morphological features, phenotype and function of endothelial cells varies according to the vascular bed examined. The sialomucin, CD34, is widely used as an endothelial marker. However, CD34 is differentially expressed on endothelial cells in different organs and in pathological conditions. Little is known about regulation of endothelial CD34 expression or function. Expression of CD34 is also strongly regulated in-vitro in endothelial cell models, including human umbilical vein endothelial cells (HUVEC) and endothelial colony forming cells (ECFC). We have therefore analysed the expression and function of CD34 by comparing CD34high and CD34low endothelial cell subpopulations. Transcriptomic analysis showed that CD34 gene and protein expressions are highly correlated, that CD34high cells proliferate less but express higher levels of IL-33 and Angiopoietin 2, compared with CD34low cells. Higher secretion levels of IL-33 and Angiopoietin 2 by CD34high HUVECs was confirmed by ELISA. Finally, when endothelial cells were allowed to interact with peripheral blood mononuclear cells, CD34high endothelial cells activated stronger proliferation of regulatory T lymphocytes (Tregs) compared to CD34low cells whereas expansion of other CD4+-T cell subsets was equivalent. These results suggest that CD34 expression by endothelial cells in-vitro associates with their ability to proliferate and with an immunogenic ability that favours the tolerogenic response.

Long term follow-up after haematopoietic stem cell transplantation for mucopolysaccharidosis type I-H: a retrospective study of 51 patients.

Mucopolysaccharidosis type I-H (MPS I-H) is a rare lysosomal storage disorder caused by α-L-Iduronidase deficiency. Early haematopoietic stem cell transplantation (HSCT) is the sole available therapeutic option to preserve neurocognitive functions. We report long-term follow-up (median 9 years, interquartile range 8-16.5) for 51 MPS I-H patients who underwent HSCT between 1986 and 2018 in France. 4 patients died from complications of HSCT and one from disease progression. Complete chimerism and normal α-L-Iduronidase activity were obtained in 84% and 71% of patients respectively. No difference of outcomes was observed between bone marrow and cord blood stem cell sources. All patients acquired independent walking and 91% and 78% acquired intelligible language or reading and writing. Intelligence Quotient evaluation (n = 23) showed that 69% had IQ ≥ 70 at last follow-up. 58% of patients had normal or remedial schooling and 62% of the 13 adults had good socio-professional insertion. Skeletal dysplasia as well as vision and hearing impairments progressed despite HSCT, with significant disability. These results provide a long-term assessment of HSCT efficacy in MPS I-H and could be useful in the evaluation of novel promising treatments such as gene therapy.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Evaluation and management of congenital tracheal stenosis.

OBJECTIVES: To outline an expert-based consensus of recommendations for the diagnosis and management of pediatric patients with congenital tracheal stenosis. METHODS: Expert opinions were sought from members of the International Pediatric Otolaryngology Group (IPOG) via completion of an 18-item survey utilizing an iterative Delphi method and review of the literature. RESULTS: Forty-three members completed the survey providing recommendations regarding the initial history, clinical evaluation, diagnostic evaluation, temporizing measures, definitive repair, and post-repair care of children with congenital tracheal stenosis. CONCLUSION: These recommendations are intended to be used to support clinical decision-making regarding the evaluation and management of children with congenital tracheal stenosis. Responses highlight the diverse management strategies and the importance of a multidisciplinary approach to care of these patients.

Natural history of Myhre syndrome.

BACKGROUND: Myhre syndrome (MS) is a rare genetic disease characterized by skeletal disorders, facial features and joint limitation, caused by a gain of function mutation in SMAD4 gene. The natural history of MS remains incompletely understood. METHODS: We recruited in a longitudinal retrospective study patients with molecular confirmed MS from the French reference center for rare skeletal dysplasia. We described natural history by chaining data from medical reports, clinical data warehouse, medical imaging and photographies. RESULTS: We included 12 patients. The median age was 22 years old (y/o). Intrauterine and postnatal growth retardation were consistently reported. In preschool age, neurodevelopment disorders were reported in 80% of children. Specifics facial and skeletal features, thickened skin and joint limitation occured mainly in school age children. The adolescence was marked by the occurrence of pulmonary arterial hypertension (PAH) and vascular stenosis. We reported for the first time recurrent strokes from the age of 26 y/o, caused by a moyamoya syndrome in one patient. Two patients died at late adolescence and in their 20 s respectively from PAH crises and mesenteric ischemia. CONCLUSION: Myhre syndrome is a progressive disease with severe multisystemic impairement and life-threathning complication requiring multidisciplinary monitoring.

Impact of COVID-19 lockdown on a tertiary center pediatric otolaryngology emergency department.

To assess the quantitative and qualitative impact of the COVID-19 lockdown on pediatric otolaryngology emergency activity. A retrospective study was conducted in a pediatric otolaryngology tertiary care center. Emergency activity during the lockdown period from March 17 to May 11, 2020, was compared to the 2019 and 2018 averages for the same period. Study data included a number of emergency consultations and the number and type of surgical procedures: infection management, endoscopic airway procedure, and post-tonsillectomy hemorrhage. Only 350 children were referred to the pediatric otolaryngology emergencies in our center during the lockdown, compared to 761 on the same period the year before (- 54%); 62 emergency surgeries were performed, compared to 93 (- 33%). The ratio between emergency surgeries and consultations was 18% in 2020, versus 12% previously (p = 0.014). The number of surgical procedures for infectious diseases decreased (- 68%), at 16% of surgical emergencies in 2020 compared to 33% previously (p = 0.017). In 2020, 52 emergency endoscopies were performed, versus 59 previously (- 12%), 27% being performed for suspected tracheobronchial or esophageal foreign bodies, compared to 66% in previous years (p < 0.0001). No post-tonsillectomy hemorrhages were managed in 2020.Conclusion: The COVID-19 lockdown changed pediatric ENT emergency activity quantitatively and also qualitatively. What is Known: • SARS-CoV-2 pandemic impacted pediatric ENT emergency activity quantitatively and qualitatively. What is New: • here was a 54% decrease in pediatric ENT emergency consultation and 33% decrease in emergency ENT surgeries. • Rates of surgery for infection of whatever type decreased by 68%.

Noninvasive Respiratory Support as an Alternative to Tracheostomy in Severe Laryngomalacia.

OBJECTIVES/HYPOTHESIS: To analyze the role of noninvasive respiratory support (NRS) as an alternative to tracheostomy in the management of severe laryngomalacia. STUDY DESIGN: We conducted a monocentric retrospective study in a tertiary pediatric care center. METHODS: All children under the age of 3 years with severe laryngomalacia, treated between January 2014 and December 2019, were included. Patient demographics, medical history, nutrition, surgery, NRS, and outcome were reviewed. Predictors for NRS were analyzed. RESULTS: One hundred and eighty-eight patients were included. Mean age was 4 ± 5 months and mean weight was 4,925 ± 1,933 g. An endoscopic bilateral supraglottoplasty was performed in 183 (97%) patients and successful in 159 (87%). NRS was initiated in 29 (15%) patients at a mean age of 3 ± 2 months (1-11 months): 15 (52%) patients were treated with NRS after surgical failure, 9 (31%) were treated with NRS initiated prior to surgery because of abnormal overnight gas exchange, and 5 (17%) were treated exclusively with NRS due to comorbidities contraindicating an endoscopic procedure. NRS was successfully performed in all patients with a mean duration of 6 ± 11 months. No patient required a tracheostomy. Univariate analysis identified the following predictors of NRS: neonatal respiratory distress (P = .003), neurological comorbidity (P < .001), associated laryngeal abnormality (P < .001), cardiac surgery (P = .039), surgical endoscopic revision (P = .007), and nutritional support (P < .001). CONCLUSION: NRS is a safe procedure, which may avoid a tracheostomy in severe laryngomalacia, in particular, in case of endoscopic surgery failure, respiratory failure before surgery, and/or severe co-morbidity. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1861-1868, 2022.

Geleophysic and acromicric dysplasias: natural history, genotype-phenotype correlations, and management guidelines from 38 cases.

PURPOSE: Geleophysic dysplasia (GD) and acromicric dysplasia (AD) are characterized by short stature, short extremities, and progressive joint limitation. In GD, cardiorespiratory involvement can result in poor prognosis. Dominant variants in the FBN1 and LTBP3 genes are responsible for AD or GD, whereas recessive variants in the ADAMTSL2 gene are responsible for GD only. The aim of this study was to define the natural history of these disorders and to establish genotype-phenotype correlations. METHODS: This monocentric retrospective study was conducted between January 2008 and December 2018 in a pediatric tertiary care center and included patients with AD or GD with identified variants (FBN1, LTBP3, or ADAMTSL2). RESULTS: Twenty-two patients with GD (12 ADAMTSL2, 8 FBN1, 2 LTBP3) and 16 patients with AD (15 FBN1, 1 LTBP3) were included. Early death occurred in eight GD and one AD. Among GD patients, 68% presented with heart valve disease and 25% developed upper airway obstruction. No AD patient developed life-threatening cardiorespiratory issues. A greater proportion of patients with either a FBN1 cysteine variant or ADAMTSL2 variants had a poor outcome. CONCLUSION: GD and AD are progressive multisystemic disorders with life-threatening complications associated with specific genotype. A careful multidisciplinary follow-up is needed.

International Pediatric Otolaryngology Group (IPOG) management recommendations: Pediatric tracheostomy decannulation.

OBJECTIVES: To provide recommendations to otolaryngologists, pulmonologists, and allied clinicians for tracheostomy decannulation in pediatric patients. METHODS: An iterative questionnaire was used to establish expert recommendations by the members of the International Pediatric Otolaryngology Group. RESULTS: Twenty-six members completed the survey. Recommendations address patient criteria for decannulation readiness, airway evaluation prior to decannulation, decannulation protocol, and follow-up after both successful and failed decannulation. CONCLUSION: Tracheostomy decannulation recommendations are aimed at improving patient-centered care, quality and safety in children with tracheostomies.

Thulium LASER for endoscopic closure of tracheoesophageal fistula in esophageal atresia's spectrum: An appropriate tool?

PURPOSE: To report our experience with endoscopic Thulium LASER for treatment of recurrent TEF after EA surgery, and for H-Type fistulas. METHODS: A retrospective chart review of consecutive patients undergoing standardized endoscopic closure as first line therapy of recurrent tracheoesophageal fistula (RTEF) and H-type fistula using Thulium LASER, from 2013 to 2019, in a pediatric tertiary care center. Control endoscopic procedure was systematically performed. If persistence of the TEF was noted an external approach was performed. Patient demographics, medical history, symptoms, TEF type, treatment modalities, complications and outcomes were collected. RESULTS: Eleven patients with tracheoesophageal fistula were included: six RTEF after primary repair of esophageal atresia and five H-type fistulas. The average age at endoscopic treatment was 19 months (SD 23 months, range 13 days-63 months). Closure of the fistula after single endoscopic procedure with Thulium LASER was obtained in 3 RTEF (50%) and 1 H-type fistula (20%). Six patients with failure of endoscopic treatment were cured after a single external procedure without any complications. One child, treated for H-type fistula, presented a severe complication of Thulium LASER treatment. Median follow-up after last repair was 24 months (range: 14-72 months). All fistulas were successfully treated. CONCLUSIONS: In H-Type fistula, success rate of Thulium LASER is only 20% and thus should not be used. In contrast, in RTEF, success rate of 50% is achieved, avoiding as many open procedures, and Thulium LASER could be considered as first line treatment. In any case, open surgery is safe and efficient and can be considered as a first-line treatment for H-type fistulas, and as a salvage treatment for endoscopic treatment failures. LEVELS OF EVIDENCE: Level IV.

Respiratory polygraphy in subjects with bronchopulmonary dysplasia: a retrospective study.

BACKGROUND: Periodic assessment of the need for oxygen supplementation and/or mechanical ventilation in children with severe bronchopulmonary dysplasia (BPD) is crucial. The aim of the study was to analyze the indications and results of respiratory polygraphies (RP) performed in preterm infants with BPD followed at a tertiary university hospital. METHODS: All subjects < 5-year-old with BPD who had a RP between September and February 2018 were included. The indications and results of RP and consequent medical management were analyzed. RESULTS: Fourteen infants (9 females, mean gestational age 27.6±3.3 weeks) underwent a RP at mean age of 26.4±19.4 months. Five subjects were evaluated for the need of long-term respiratory support (RS), 3 started continuous positive airway pressure (CPAP), 2 were weaned from RS. Four subjects underwent RP for suspected obstructive sleep apnea (OSA), one started on CPAP. Central apnea syndrome (CSA) was confirmed in 2 subjects and one was started on non-invasive ventilation. RP allowed safe tracheostomy decannulation in 2 subjects. Finally, RP was normal in one patient who had a brief resolved unexplained event (BRUE). CONCLUSIONS: RP represents an important tool for the evaluation of children with BPD and leads to important therapeutic decisions.

International Pediatric Otolaryngology Group (IPOG) consensus recommendations: Management of suprastomal collapse in the pediatric population.

INTRODUCTION: Suprastomal Collapse (SuStCo) is a common complication of prolonged tracheostomy in children. There is a paucity of literature on this subject, especially regarding how to manage significant suprastomal collapse that prevents safe decannulation. OBJECTIVE: Provide a definition, classification system, and recommend management options for significant suprastomal collapse in children with tracheostomy. METHODS: Members of the International Pediatric Otolaryngology Group (IPOG) who are experts in pediatric airway conditions were surveyed and results were refined using a modified Delphi method. RESULTS: Consensus was defined as > 70% agreement on a subject. The experts achieved consensus: CONCLUSION: This consensus statement provides recommendations for medical specialists who manage infants and children with tracheostomies with significant Suprastomal Collapse. It provides a classification system to facilitate diagnosis and treatment options for this condition.

International Pediatric Otolaryngology Group (IPOG): Consensus recommendations on the prenatal and perinatal management of anticipated airway obstruction.

OBJECTIVE: To make recommendations on the identification, routine evaluation, and management of fetuses at risk for airway compromise at delivery. METHODS: Recommendations are based on expert opinion by members of the International Pediatric Otolaryngology Group (IPOG). A two-iterative Delphi method questionnaire was distributed to all members of the IPOG and responses recorded. The respondents were given the opportunity to comment on the content and format of the survey, which was modified for the second round. "Consensus" was defined by >80% respondent affirmative responses, "agreement" by 51-80% affirmative responses, and "no agreement" by 50% or less affirmative responses. RESULTS: Recommendations are provided regarding etiologies of perinatal airway obstruction, imaging evaluation, adjunct evaluation, multidisciplinary team and decision factors, micrognathia management, congenital high airway obstruction syndrome management, head and neck mass management, attended delivery procedure, and delivery on placental support procedure. CONCLUSIONS: Thorough evaluation and thoughtful decision making are required to optimally balance fetal and maternal risks/benefits.

Developmental changes of upper airway dimensions in children.

BACKGROUND: Knowledge about airway dimensions during child growth is of paramount importance for pediatric clinical practice. Decisions about airway management in children are based on relatively limited, imprecise, or incomplete data about airway size. AIMS: The aim of this work was to determine the anatomical development and size of airway structures from birth to adolescence using high-resolution computed tomography scans and to study the correlation between airway measurements and biometric data. METHODS: We conducted a retrospective study of all high-resolution computed tomography scans including the respiratory tract, performed in our tertiary pediatric center (for reasons unrelated to airway symptoms) between June 1, 2016, and October 15, 2017, on children aged from 1 day to 14 years old. On each scan, 23 measurements of the larynx, trachea, and mainstem bronchi were performed. Patients were stratified into 16 groups according to their age. We calculated median value for each measurement in each group. Statistical models were calculated to explore correlation between measurements and age or weight. RESULTS: A total of 192 scans were included (127 boys/65 girls). The mean age was 7 years. The correlations between airway measurements and age or weight were always significant. The relationship between measurements and age was found to be suitably represented by a cubic polynomial equation suggesting that the airway has a rapid growth phase in the first 3 years, followed by a slow growth phase and a second rapid growth phase during adolescence. The most relevant biometric parameter was age concerning 21 of the measurements. CONCLUSION: This comprehensive anatomical database of upper airway dimensions provides important data in the field of pediatric airway anatomy, particularly relating to the cricoid. We demonstrated that laryngeal, tracheal, and bronchial parameters correlate better to age and have three different growth phases.