Evaluation of intracochlear pressure during fluid application in the model and human petrous bone

Introduction The aim of the application of substances of an inner ear therapy is the atraumatic execution as well as a homogeneous distribution over the cochlea in a reasonable time frame. Depending on the substance (vectors, smart molecules, medication) there are special challenges concerning infectious properties, colloidal properties and binding to carrier substances. Common to all substances is the need for atraumatic application. The introduction of substances leads to intracochlear pressure changes, which can have a traumatic effect. The aim for this study was to compare different techniques of substance application and their effects on intracochlear pressure in different models.

Material and Methods Intracochlear pressure was measured by fiberoptic pressure sensors in artificial cochlea models and in a human temporal bone. In all models the substance was applied by means of an inner ear catheter (MED-EL) via the round window with and without methylene blue as well as with and without a second access to the cochlea (helicotrema/oval window). Pressure was removed via an additional burr channel or the lateral arcade.

Results The application of substances showed significant differences in intracochlear pressure at the same velocity between a single-hole and a two-hole technique. Furthermore, there was a difference in pressure between the single-hole technique and the two-hole technique.

Summary In addition to a faster homogeneous distribution, a lower intracochlear pressure is shown when using a two-hole technique.

Publication History

Article published online:
12 May 2023