title: Morphological sequence of Plastipore extrusion in experimental otitis media.
abstract: OBJECTIVE
  Plastipore prostheses are still used by many surgeons, although the functional results are controversial. The aim of this study was the morphological analysis of Plastipore material performance in the middle ear of rats, with special attention to extrusion.
  
  
  METHODS
  Twenty-four Wistar rats were given implants made of commercially available Plastipore and assigned to 3 groups: group A, with implantation in a healthy middle ear; group B, with implantation and cauterization of the nasopharyngeal orifice of the eustachian tube (hypoventilation); and group C, with implantation, cauterization of the eustachian tube, and bacterial inoculation with Pseudomonas aeruginosa.
  
  
  RESULTS
  The pathological study showed in nearly all cases the disintegration of the biomaterial. Adhesion between the biomaterial and bone could be seen in 1 rat from group C (hypoventilation and infection). In group C, the Plastipore was in contact with the tympanic membrane in 1 case and was extruding in 2 animals. Different phases of extrusion were defined. No extrusion was observed in the other groups.
  
  
  CONCLUSIONS
  The sequential stages of Plastipore extrusion are demonstrated. Infection seems to be the most important factor in Plastipore extrusion in our model.
authors.affiliation: Ear Research Group, Department of Otorhinolaryngology, University Hospital Puerta de Hierro, Autonomous University of Madrid, Madrid, Spain.
authors.forename: Almudena
authors.initials: A
authors.lastname: Trinidad
authors.forename: Javier
authors.initials: J
authors.lastname: Vicente
authors.forename: José María
authors.initials: JM
authors.lastname: Verdaguer
authors.forename: Rosa
authors.initials: R
authors.lastname: Daza
authors.forename: José Ramón
authors.initials: JR
authors.lastname: García-Berrocal
authors.forename: Rafael
authors.initials: R
authors.lastname: Ramírez-Camacho
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D003054:Cochlear Implants; D004195:Disease Models, Animal; D005500:Follow-Up Studies; D008297:Male; D010033:Otitis Media / Q000473:pathology / Q000601:surgery*; D011095:Polyethylenes; D011126:Polypropylenes; D011474:Prosthesis Design; D011475:Prosthesis Failure; D051381:Rats; D017208:Rats, Wistar; D013526:Surgical Mesh
chemical_list: D001672:Biocompatible Materials; C016674:Plastipore; D011095:Polyethylenes; D011126:Polypropylenes