title: Treatment of middle ear ventilation disorders: sheep as animal model for stenting the human Eustachian tube--a cadaver study.
abstract: Eustachian tube disorders can lead to chronic otitis media with consecutive conductive hearing loss. To improve treatment and to develop new types of implants such as stents, an adequate experimental animal model is required. As the middle ear of sheep is known to be comparable to the human middle ear, the dimensions of the Eustachian tube in two strains of sheep were investigated. The Eustachian tube and middle ear of half heads of heathland and blackface sheep were filled with silicone rubber, blended with barium sulfate to induce X-ray visibility. Images were taken by digital volume tomography. The tubes were segmented, and a three-dimensional model of every Eustachian tube was generated. The lengths, diameters and shapes were determined. Additionally, the feasibility of endoscopic stent implantation and fixation was tested in cadaver experiments. The length of the tube between ostium pharyngeum and the isthmus and the diameters were comparable to published values for the human tube. The tube was easily accessible through the nose, and then stents could be implanted and fixed at the isthmus. The sheep appears to be a promising model for testing new stent treatments for middle ear ventilation disorders.
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany.
authors.forename: Felicitas
authors.initials: F
authors.lastname: Miller
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany.
authors.forename: Alice
authors.initials: A
authors.lastname: Burghard
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Salcher
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Hearing4all Cluster of Excellence, Hannover Medical School, Hannover, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Scheper
authors.affiliation: Department of Immunology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Leibold
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Hearing4all Cluster of Excellence, Hannover Medical School, Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.affiliation: Department of Otolaryngology, Hannover Medical School, Hannover, Germany; Hearing4all Cluster of Excellence, Hannover Medical School, Hannover, Germany.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Paasche
mesh_terms: D000818:Animals; D002102:Cadaver; D054893:Cone-Beam Computed Tomography; D004427:Ear Diseases / Q000175:diagnosis / Q000601:surgery*; D004432:Ear, Middle / Q000473:pathology / Q000601:surgery*; D004724:Endoscopy; D005064:Eustachian Tube / Q000473:pathology / Q000601:surgery*; D006314:Hearing Loss, Conductive / Q000517:prevention & control; D006801:Humans; D008876:Middle Ear Ventilation / Q000379:methods; D023421:Models, Animal; D010033:Otitis Media / Q000517:prevention & control; D015203:Reproducibility of Results; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis / Q000601:surgery*; D015607:Stents