To report normative data for incus and stapes motion using laser Doppler vibrometry (LDV) during middle ear surgery and to discuss possible limitations of the procedure.
Institutional review board–approved, retrospective study of data from patients undergoing the Envoy Esteem implantable device at 3 institutions.
Quaternary referral health system.
Eligibility criteria: patients sucsessfully implanted with an Esteem device.
Data from 70 patients undergoing the Envoy Esteem procedure were reviewed. Sound at 100 dB and 50 frequencies ranging from 125 to 8,000 Hz were used during the procedure. LDV was performed to measure the displacment of the body of the incus and the posterior crus of the stapes to assess whether there was sufficient ossicular mobility to allow for implantation.
The average displacement of the ossicles for all 70 patients was collected and analyzed. The trend was an average displacement around 100 nm from 125 to 500 Hz for both the incus and stapes with a linear decline starting at 1,000 Hz for the incus and 500 Hz for the stapes, with slightly greater displacement of the stapes at higher frequencies.
This is the first article to report in vivo measures of ossicular mobility. These data help to understand the micromechanics of ossicular motion as well as the use and limitations of LDV. This information may lead to a prescreening process for implanted middle ear devices that function by overdriving the stapes.
*Henry Ford Health System, Department of Otolaryngology–Head and Neck Surgery, Detroit, Michigan; †Loyola University Chicago, Department of Otolaryngology–Head and Neck Surgery, Maywood, Illinois; ‡Shohet Ear Associates, Newport Beach, California; §Wayne State University School of Medicine, Detroit, Michigan; and ∥Envoy Medical Corporation, Saint Paul, Minnesota, U.S.A.
Address correspondence and reprint requests to Michael D. Seidman, M.D., F.A.C.S., Henry Ford Health System, Department of Otolaryngology–Head and Neck Surgery, Division of Otologic/Neurotologic Surgery, 6777 West Maple Road, West Bloomfield, MI 48322; E-mail: email@example.com
Disclosures: K.V. is an employee of Envoy Medical Corporation and assisted with data collection and analysis.
There was no external funding for this project.