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RESEARCH PRODUCT

Hearing results after hypotympanotomy for glomus tympanicum tumors.

subject

description

We postulate, that glomus tympanicum tumors (GTTs) may be safely removed without interference with the ossicular chain via a hypotympanotomy approach.Prospective, nonrandomized anatomic and clinical study.Tertiary referral center.All 17 patients between 1989 and 2009 with GTTs without involvement of the lumen of the jugular bulb.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.To evaluate if GTTs can be completely resected without interference with the ossicular chain to improve conductive hearing loss.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.Our approach demonstrated a safe avenue for complete tumor removal without interference with the continuity of the ossicular chain.