Ex vivo ovine model for pediatric flexible endoscopy training.

OBJECTIVES

Medical students and residents in training have limited opportunities to develop pediatric endoscopy skills and would benefit from a realistic simulation model. We sought to develop such a model for flexible endoscopy using fresh head and neck tissue from young sheep.

METHODS

Tissue was collected from pre-pubescent sheep (n=5; mean age: 4 months; mean mass: 28kg) following humane euthanasia at the end of an in vivo protocol. No live animals were used in this study. The head and neck of the sheep were disarticulated 4-6cm above the sternal notch and stored at 5°C for 1-5 days. With the preparation was supported in supine position, flexible nasopharyngolaryngoscopy and transnasal endoscopic intubation were performed with video recording.

RESULTS

Five sheep were studied. Endoscopy was performed by a medical student under direct supervision by a pediatric otolaryngologist. Differences between ovine and human pediatric airway anatomy were defined.

CONCLUSIONS

Despite variations in proportion and structure, the experience of passing a flexible nasopharyngoscope through a sheep's airway is remarkably similar to pediatric endoscopy. The nasal anatomy is elongated, but very much like a child's in terms of anatomy, color and texture. The tactile feedback is nearly identical. Annoying secretions and their associated "whiteout" phenomena nicely simulate these challenges in pediatric endoscopy. When performing transnasal intubation, navigating to the larynx and advancing an endotracheal tube under guidance have the look and feel of the pediatric procedure. Issues of cost, availability, risk of zoonotic infection, and ethics are discussed.