Congenital nasal pyriform aperture stenosis; our experience of 34 cases.

OBJECTIVES: To study our population of patients with congenital nasal pyriform aperture stenosis (CNPAS) in terms of incidence and socioeconomic status; the effect of pyriform aperture size, gestational age, birth weight, and whether congenital abnormalities are associated with surgical requirement. METHODOLOGY: Retrospective case note review of all patients treated for CNPAS at a single tertiary paediatric referral site was undertaken. Diagnosis was made on the basis of a pyriform aperture of <11 mm on CT scanning; patient demographics were collected to explore risk factors for surgery and surgical outcomes. RESULTS: 34 patients were included in the series, 28 (84%) of whom underwent surgery. 58.8% of subjects had an associated mega central incisor. A smaller pyriform aperture size was seen in neonates requiring surgery (4.87 mm ± 1.24 mm vs 6.55 mm ± 1.41 mm, p = 0.031). There was no difference in gestational age in neonates requiring surgery (p = 0.074). Requirement for surgery was not associated with co-existing congenital anomalies (p = 0.297) or lower birth weight (p = 0.859). Low socioeconomic status was not significantly associated with requiring surgery but a potential link between CNPAS and deprivation was identified (p = 0.0583). CONCLUSION: These results suggest that a pyriform aperture of less than 6 mm requires surgical intervention. Associated birth anomalies add additional management considerations but in this cohort were not associated with increased need for surgery. A potential association between CNPAS and low socioeconomic status was identified.

Paediatric tracheobronchomalacia: Incidence, patient characteristics, and predictors of surgical intervention.

OBJECTIVES: Tracheobronchomalacia (TBM), a condition where an abnormality of the tracheal walls causes collapse during the respiratory cycle, is a common cause of airway obstruction in childhood. TBM can present with a large spectrum of disease severity and underlying pathologies that may be managed medically and surgically, and it is not always clear which patients would most benefit from surgical intervention. We aim to describe the incidence, patient characteristics, and predictors of surgical intervention in a large cohort of paediatric patients. METHODS: We performed a retrospective review of all children diagnosed with TBM to a paediatric Otolaryngology unit in the west of Scotland between 2010 and 2020. Odds ratios for clinical predictors of surgery were calculated using logistic regression with uni- and multivariate analysis. RESULTS: 249 patients were identified of which 219 proceeded to data collection. Primary malacia was noted in 161 (73.5%) and secondary in 58 (26.5%). Causes of secondary malacia included compression by the innominate artery (11%) and vascular rings (7.8%). Surgical interventions were performed in 28 patients (12.8%) including division of vascular ring, aortopexy, and surgical tracheostomy. Multivariate analysis showed secondary TBM, acute life-threatening events, and difficulty weaning from mechanical ventilation were independent risk factors for surgical intervention. CONCLUSIONS: TBM can present with a myriad of airway symptoms and is frequently associated with other airway and mediastinal pathologies necessitating multiple interventions. Children aged <1 year present with a more severe form of the disease and the presence of particular independent risk factors may indicate a need for surgical intervention.

Feasibility of ovine and porcine models for simulation training in parotid surgery and facial nerve dissection.

PURPOSE: To assess and compare the feasibility of using ovine and porcine models as surgical simulation training tools for otolaryngology trainees performing parotid surgery and facial nerve dissection. METHODS: Trainees performed parotid surgery (total parotidectomy, retrograde facial nerve dissection and facial nerve grafting) on an ovine and porcine model. Participants completed a 22-item, five-point Likert scale questionnaire on each model, assessing three validation domains; face validity (FV), global content validity (GCV) and task-specific content validity (TSCV). Data were prospectively collected and analysed using descriptive and non-parametric statistics. RESULTS: Twelve trainees completed two consecutive parotidectomies and facial nerve dissections on an ovine and porcine model. Twenty-four dissections were completed. Validation questionnaires were completed for each model by all trainees. The ovine model achieved median validation threshold scores (≥ 4/5) for all aspects of FV, GCV and TSCV. The porcine model did not achieve validation threshold scores for any aspect of the validation questionnaire. Comparison of the ovine and porcine model demonstrated that the ovine model was statistically superior to the porcine model across most validation criteria excluding realistic appearance of skin, identification and ligation of the trans-oral parotid duct and facial nerve grafting. CONCLUSION: Adequate experience with facial nerve dissection during parotid surgery is vital to ensuring good outcomes and avoiding complications. This study is the first to compare validity of two animal models for simulation training in parotid surgery and facial nerve dissection. We have validated the ovine model as a useful tool for simulation training and advocate its incorporation into otolaryngology training programmes.

Validation of Animal Models for Simulation Training in Pediatric Laryngotracheal Reconstruction.

OBJECTIVES: To assess and compare the face (FV) and content validity (CV) of three ex vivo animal models for simulation training in pediatric laryngotracheal reconstruction (LTR). METHODS: Feasibility of performing LTR was assessed on the head and neck of three different animals (lamb/suckling-pig/rabbit) and laryngeal dimensions and qualitative observations were recorded. A 19-item five-point Likert scale questionnaire was completed for each model to assess FV and CV. Data was prospectively collected and analyzed using descriptive and nonparametric statistics. RESULTS: All three models were suitable for LTR simulation with laryngeal dimensions corresponding to 0-2 years (rabbit), 5-10 (pig) and >10 years (lamb model). Five trainees and five expert pediatric otolaryngologists performed LTR on each model. The overall median FV score was 5 for the lamb model (IQR 4-5), 3 for the rabbit (IQR 2-3), and 4 for the pig (IQR 4-4). The overall median CV score was 5 for the lamb (IQR 5-5), 2 for the rabbit (IQR 2-3), and 4 for the pig model (IQR 4-4). Comparison of the models demonstrated the lamb to be favored as the most realistic and practical model for simulation training in pediatric LTR, with both the lamb and the porcine model attaining validation thresholds. CONCLUSION: Our study is the first comparative validation assessment of animal models for use in pediatric LTR simulation and it supports the use of ex vivo lamb and porcine models for use in LTR surgical skills training. The lamb model was the favored simulation model while the rabbit was considered inferior for simulation training in pediatric LTR. LEVEL OF EVIDENCE: 3b.

Prevalence, risk factors and management strategies for otological problems in girls with Turner syndrome.

AIM: To determine the prevalence and risk factors of ear disease in Turner syndrome (TS), propose an algorithm for future surveillance and recommend preventative strategies. METHODS: Review of TS patients seen in the West of Scotland between 1989 and 2015, with questionnaire follow-up in 2015. RESULTS: Of 168 girls, median age 27.3 (3.8-47.2) years, ear problems occurred more frequently with 45,X and 45,X/46,XiXq than other karyotypes: 71/103 (69%) versus 23/65 (35%). Recurrent acute otitis media (AOM) first developed at 0-5 years in 23 (40%) girls, persisting in 16 (10%) at 5-10 years; and first developing at 5-10 years in 11 (7%). Persistent otitis media with effusion (OME) first developed at 0-5 and 5-10 years in 23 (40%) and 14 (8%) girls. Recurrent AOM was significantly linked with cholesteatoma in 8 (4.9%) girls (7 aged >10 years). Permanent hearing loss was documented in 28 girls (16.7%), with 16 (9.5%) receiving hearing aids (bone-anchored in 3). CONCLUSION: Acute otitis media and OME occur commonly in preschool TS girls and may persist or newly develop in later childhood. Recurrent AOM predisposes to cholesteatoma. Strategies to reduce otological morbidity include: intensive patient education, annual audiology, vaccinations and a randomised trial of antibiotic prophylaxis in high-risk groups.

A systematic review of simulated laryngotracheal reconstruction animal models.

OBJECTIVES: Review of the literature to identify practical, high-fidelity, commercially available animal models for simulation training and surgical skills maintenance in laryngotracheal reconstruction (LTR). METHODS: A systematic review of PubMed and Embase databases was conducted independently by two authors, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms included "laryngotracheal reconstruction," "laryngotracheoplasty," "pig and larynx," "sheep and larynx," and "rabbit and larynx." Articles were then assessed, identifying model cost and availability, model validation, feasibility as a training tool, and verisimilitude to pediatric LTR. RESULTS: In total, 79 articles were considered suitable for inclusion in the study, incorporating both in vitro and in vivo models. Models utilized included rabbit (n = 69), pig (n = 7), sheep (n = 1), and goat (n = 2). The rabbit model was similar in size to the neonate, but differences in laryngeal anatomy and cartilage texture made graft insertion difficult. The anatomy of the pig, sheep, and goat larynges more closely resembled the pediatric patient, allowing improved grafting, but corresponded more in size to that of an older child. Commercial availability of the pig and sheep was considered greatest, and was reflected in cost. None of the animal models identified in the literature have been validated as a simulation tool. CONCLUSIONS: The rabbit, sheep and pig models seemed to demonstrate the greatest potential for use as advanced pediatric airway surgery simulation models, with the rabbit model being most utilized in the literature. However, as yet there have been no models formally validated as a simulation training tool. Laryngoscope, 129:235-243, 2019.

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

AIM: Airway disorders are common in children with Down's syndrome. We report the findings on airway endoscopy in a birth cohort of children from a well-defined geographical area, in order to estimate true population prevalence of airway problems in children with Down's syndrome. METHOD: Retrospective case note review over a 20-year period between 1993 and 2013 for all children in Greater Glasgow born with Down's syndrome, identified through the hearing surveillance programme. All children undergoing airway endoscopy under general anaesthesia for investigation of potential airway symptoms (stridor, hoarseness, recurrent croup and difficulties with intubation/extubation) were studied in detail to identify the number with laryngeal, tracheal or bronchial pathology. RESULTS: All 239 children (F:M=1.15:1) were reviewed. Of these, 39 (16.3%) underwent microlaryngoscopy-bronchoscopy under general anaesthesia for airway symptoms. The main presentations were stridor (9), extubation problems (12) and exacerbations of recurrent croup (7). Thirty-three were found to have at least one airway diagnosis (13.8%) including trachaeobronchomalacia (17), laryngeal cleft (2), laryngomalacia (2), tracheal compression (2), vocal cord paralysis (1), acquired tracheal stenosis (2) and symptomatic subglottic stenosis (14). CONCLUSION: Laryngo-tracheo-bronchial pathology is much more common in children with Down's syndrome than in the general population, particularly subglottic stenosis and tracheal problems.

Treatment of tracheomalacia with aortopexy in children in Glasgow.

OBJECTIVE: The aim of this study was to assess outcomes of infants and children undergoing aortopexy and to try and establish which children would derive the greatest benefit from this complex intervention. Materials and METHODS: This is a retrospective case series in a pediatric tertiary referral hospital between 1993 and 2012. A case sheet review was performed to collect demographic data and identify outcomes for each child. The effects of the subtype of tracheomalacia, weight at surgery, symptoms at presentation, surgical approach, and preoperative ventilation were considered. RESULTS: There were 30 children who underwent aortopexy during the study period. Of the 30 children in the study, 21 children (70%) were male. The gestational age at birth ranged between 25 and 41 weeks (9 children [30%] were preterm). Age at surgery was between 2 and 140 weeks (mean; 31.5 weeks, median; 26 weeks). The onset of symptoms was between birth and 18 months (mean; 3.8 months, median; 3.5 months). The presenting symptoms were stridor (n = 9; 30%), failed extubation (n = 4; 13%), death attacks (n = 8; 27%), and cyanosis (n = 9; 30%). The underlying pathology was primary in 10 children (33%) and secondary in 18 children. The diagnosis was made by bronchoscopy in 26 children (93%). Imaging was performed in 25 children (83%). Aortopexy in our institution is performed by general pediatric surgeons (n = 8; 27%) and cardiothoracic surgeons (n = 22; 73%). In the immediately postoperative period, 25 children (83%) were thriving. Of the children that required another procedure; 1 child was reintubated (3%), 2 children had a tracheostomy (6%), 1 child had a stent (3%), and 2 children died (6%). Clinical follow-up of these children was between 1 month and 12 years. Long term, in 22 children (73%) were asymptomatic. CONCLUSION: There were no clinical predictors of outcome identified, but aortopexy is a safe effective procedure for children with severe tracheomalacia.

Residual tracheal pouch after repair of tracheaoesophageal fistula: endoscopic KTP laser treatment.

There is usually a small pouch within the trachea after ligation and division of a tracheoesophageal fistula. Most are asymptomatic, but some present with cough or by causing problems with endotracheal or tracheostomy tubes. Repeated open transthoracic surgery to ligate the fistula closer to the tracheal wall is problematic because the pouch is within the wall itself. We have found that bronchoscopic treatment with the potassium (K) Titanyl Phosphate laser to divide the party wall provides a quick and effective way to deal with the pouch, and we present a series of four cases to illustrate this technique.

Development of bioassessment-based benchmarks for iron.

Current water-quality criteria for metals typically are derived from toxicity tests with the metal dissolved in clean laboratory water. Estimating the toxicity of iron from such tests, however, is extremely difficult because of the complex solubility and toxicity characteristics of the ferrous and ferric forms of the metal in freshwater. Consequently, a criterion for dissolved iron in freshwater derived from standard laboratory bioassays may not accurately describe the actual bioavailability and toxicity of this metal. A new approach is necessary to adequately protect aquatic life from the direct (toxic) and indirect (physical) negative effects of iron. We present a novel methodology to derive bioassessment-based benchmarks for total iron. This approach involves the use of quantile regression to model the decline in maximum abundance of taxa along a gradient of increasing iron concentrations. The limiting function (e.g., 90th quantile) is used to project the iron concentration associated with a selected reduction in maximum number of organisms (e.g., 20%). The projected declines in abundance of aquatic organisms are interpreted within the larger context of biological responses to increasing levels of stress (i.e., a biological condition gradient). Projections of iron concentration associated with multiple levels of reduction are selected to establish acceptable levels of change in the various tiers of a biological community. The bioassessment-based benchmarks that we establish for total iron (0.21 and 1.74 mg/L) are based on the assumption that if ecological effects-based criteria for total iron are derived and applied, the structure and function of the aquatic community will be protected.