Pressure assessment of superior semicircular canal dehiscence repair techniques--a temporal bone study

To develop a cadaveric temporal bone preparation to compare the strength of superior semicircular canal dehiscence (SCD) repair techniques.

Superior semicircular canal dehiscence syndrome is a clinical condition with a variety of auditory and vestibular symptoms resulting from a mobile third window into the inner ear. Patients with incapacitating symptoms often undergo surgical repair. There have been no previous studies to directly assess the strength of techniques used for repair of SCD.

The ability of repair techniques to withstand prolonged pressure application was measured in prepared temporal bones (n = 5). Pressure changes were compared with the superior semicircular canal intact and with the dehiscence repaired via three repair techniques (resurfacing, plugging, and combined plugging and resurfacing).

Each of the three repair techniques resisted loss of applied pressure as well as the closed system before creation of the dehiscence at pressures comparable to high-normal intracranial pressure (23-25 cm H2O). At supra-physiologic pressure levels (45-55 cm H2O), the combined plugging and resurfacing technique showed consistent resistance to loss of pressure as compared to instances of failure with either of the single repair approaches.

Findings from the cadaveric temporal bone preparations revealed that even immediately after repair, each of the three main techniques are equally resistant to the application of high-normal intracranial pressure levels. However, with consistent resistance to loss of pressure across all trials, the combined plugging and resurfacing technique may offer improved resistance in instances where supra-physiologic pressures are encountered.