title: Hearing results after hypotympanotomy for glomus tympanicum tumors.
abstract: OBJECTIVE
  We postulate, that glomus tympanicum tumors (GTTs) may be safely removed without interference with the ossicular chain via a hypotympanotomy approach.
  
  
  METHODS
  Prospective, nonrandomized anatomic and clinical study.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  All 17 patients between 1989 and 2009 with GTTs without involvement of the lumen of the jugular bulb.
  
  
  METHODS
  We used a modified hypotympanotomy approach. Our technique is a modification of the one first published by Shambaugh (1955). Pure-tone audiograms were performed in all patients. Preoperative and postoperative audiograms were modeled in a linear mixed model evaluating hearing threshold for air and bone conduction and air-bone gap at 500, 1,000, 2,000, and 3,000 Hz. In an effort to preserve the normal sound conducting apparatus and hearing, we used a retroauricular approach, exposing widely the jugular bulb, the carotid artery, the protympanum, and even the bony part of the Eustachian tube via a hypotympanotomy. Three formalin-fixed and one macerated temporal bones were dissected step by step under the operating microscope to demonstrate the approach in cadaver dissections.
  
  
  METHODS
  To evaluate if GTTs can be completely resected without interference with the ossicular chain to improve conductive hearing loss.
  
  
  RESULTS
  We found a substantial improvement of hearing threshold after surgery at all frequencies in air conduction. For bone conduction, there was only a slight gain within random variation. The air-bone gap decreased significantly after surgery.
  
  
  CONCLUSIONS
  Our approach demonstrated a safe avenue for complete tumor removal without interference with the continuity of the ossicular chain.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany. papaspyrou@hno.klinik.uni-mainz.de
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papaspyrou
authors.forename: Torsten
authors.initials: T
authors.lastname: Mewes
authors.forename: Miklós
authors.initials: M
authors.lastname: Tóth
authors.forename: Irene
authors.initials: I
authors.lastname: Schmidtmann
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Amedee
authors.forename: Wolf J
authors.initials: WJ
authors.lastname: Mann
mesh_terms: D001844:Bone Conduction / Q000502:physiology; D004424:Ear Canal / Q000473:pathology; D004428:Ear Neoplasms / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D043604:Glomus Tympanicum Tumor / Q000503:physiopathology / Q000601:surgery*; D006309:Hearing / Q000502:physiology*; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D013701:Temporal Bone / Q000502:physiology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014432:Tympanic Membrane / Q000601:surgery*