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.

Concurrent subglottic and carotid sheath haemangiomas in a paediatric patient - an extremely rare clinical entity.

Multiple haemangiomas of the head and neck area have been reported sporadically in the literature. Concurrent subglottic and carotid sheath haemangiomas have not been reported before in the paediatric population. The authors present the case of a 13-week-old child admitted under the paediatric ENT team with stridor. Diagnostic micro-laryngoscopy identified a subglottic haemangioma as the cause of stridor and subsequent magnetic resonance imaging demonstrated an incidental 7 cm carotid sheath lesion extending from the skull base to the superior mediastinum. Subsequent biopsy confirmed a benign infantile haemangioma. To our knowledge, this is the first reported case of concurrent subglottic and carotid sheath infantile haemangiomas in a paediatric patient. Here we discuss the clinical features and management of infantile haemangioma.

Twenty-year observational study of paediatric tonsillitis and tonsillectomy.

INTRODUCTION: Tonsillectomy is now only indicated in the UK when specific criteria are met, as outlined by the Scottish Intercollegiate Guidelines Network (SIGN) and The National Institute for Health and Care Excellence (NICE). As a result, fewer numbers of tonsillectomy are being performed. Tonsillectomy is the primary treatment for recurrent tonsillitis; therefore, we hypothesise that acute admissions to hospital with tonsillitis and infective complications will have risen since criteria were introduced. Our aim was to assess the rates of acute hospital admissions with tonsillitis in children and the factors associated with this. METHODS: Data were provided by Information Service Division for all under 16s in Scotland between 1996/1997 and 2016/2017. Socioeconomic background was determined from the Scottish Index of Multiple Deprivation (SIMD) score. Poisson regression analysis was used to model predictors of surgery and correlation analysis to study the relationship between tonsillitis and other factors. RESULTS: 60 456 tonsillectomies were performed. The number of tonsillectomies dropped significantly following the introduction of SIGN guidelines, and the rates of tonsillitis increased; however, admissions with tonsillitis were already on an upward trajectory. Children from the most deprived areas were 72.0% (95% CI 60% to 85%, p<0.001) more likely to receive tonsillectomy and were also more likely to be admitted with tonsillitis than the least deprived areas. CONCLUSION: Tonsillectomy and tonsillitis rates are highest in the most deprived; postulated reasons include antibiotic stewardship and difficulty accessing primary care. Current guidelines on tonsillectomy may be disproportionately harmful in children from deprived households.

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.

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.

Otological surgery in paediatric photosensitive patients.

There are a wide range of genetic and auto-immune conditions where UV light exposure poses a threat of UV irradiation to the external auditory canal, tympanic membrane and surrounding skin. Preoperative Ultraviolet Light (UV) measurements were taken in the operating theatre with standard operating microscope and an approved UV light meter prior to surgery on a patient with xeroderma pigmentosa. UV light meter readings of UV index 75 were taken at an operating distance of 290mm. Proceeding with otological surgery with a high UV index would result in a significant UV radiation burn. Utilising a Dermagard and a specific UV filter applied to the microscope resulted in acceptable UV light readings. We highlight the potential morbidity of otological surgery in paediatric photosensitive conditions. We also recommend a management plan to avoid damage by UV radiation in photosensitive patients.