Consensus statement on round window vibroplasty.

OBJECTIVE: This study aimed to review current knowledge regarding implantation of the Vibrant Soundbridge floating mass transducer (FMT) at the round window (round window vibroplasty) as well as to form a consensus on steps for a reliable, stable surgical procedure. DATA SOURCES: Review of the literature and experimental observations by the authors. CONCLUSION: Round window (RW) vibroplasty has been established as a reliable procedure that produces good and stable results for patients with conductive or mixed hearing loss. The experience gained over the past few years of the authors' more than 200 implantations has led to consensus on several key points: (1) a wide and bloodless access to the middle ear with facial nerve monitoring, (2) the careful and correct identification and exposure of the round window membrane, (3) a good setup for efficient energy transition of the FMT, namely, perpendicular placement of the FMT with no contact to bone and the placement of cartilage behind the FMT to create a preloaded "spring" function, and (4) 4 points of FMT fixation: a rim of the round window bony overhang left intact both anterior and posterior to the FMT, conductor link stabilization, and cartilage behind the FMT. In addition, the FMT should be covered with soft tissue.

Coupling the Vibrant Soundbridge to cochlea round window: auditory results in patients with mixed hearing loss.

OBJECTIVE: To assess the functional results of the Vibrant Soundbridge (VBS) placed on the round window (RW) in patients with mixed hearing loss. STUDY DESIGN: Retrospective evaluation of functional hearing, with measurements performed 7 to 9 months postoperatively. SETTINGS: Two tertiary referral hospital centers. SUBJECTS: Twelve individuals with mixed severe hearing loss associated with chronic suppurative otitis media and otosclerosis. INTERVENTION: Surgical placement of the VBS mechanical effector in close contact with the RW membrane to directly drive the inner ear fluids. MAIN OUTCOME MEASUREMENT: Functional hearing gain as analyzed via pure-tone audiometry and speech audiometry with VBS off and on in quiet and in noise. RESULTS: We observed a mean gain of 37.5 dB (0.5-4 kHz) with wide individual differences. The overall gain is mainly due to the air-bone gap recovery, whereas a further 12-dB mean improvement of air-conducted threshold is evident at 2 kHz. The speech reception threshold in quiet shows a mean gain of 24 dB, whereas in noise, it requires a signal-to-noise ratio 7 to 13 dB greater than normal-hearing controls. All patients are daily users of their VBS device. CONCLUSION: A middle ear implant capable of directly driving the cochlear fluids seems to be a promising alternative for individuals with a severe to profound mixed hearing loss. However, variability in hearing recovery is great, likely reflecting variability in responsiveness of the cochlea associated with chronic pathologic findings and, possibly, variability in how the VBS effector interfaces with the RW. Modifying the shape of the VBS effector can improve the mechanical coupling to the RW to better exploit the device's amplification power.