Scala tympani cochleostomy for cochlear implantation

The use of cochlear implantation to treat sensorineural hearing loss continues to evolve as an increasing number of both adult and pediatric patients undergo this life-changing surgery. As our understanding of electrical stimulation of the auditory system unfolds, the importance of proper cochleostomy placement and intracochlear electrode positioning continues to evolve. Currently, atraumatic intracochlear electrode array implantation into scala tympani appears to optimize performance while providing the opportunity for hearing preservation for the purposes of bimodal stimulation. With these objectives in mind, this article describes the authors' surgical approach to gain access to scala tympani with the intent of minimizing trauma to the underlying structures. This approach is based on the results of multiple clinical and anatomical studies as well as on data from various temporal bone experiments. Based herein, the authors perform either direct round window insertions or create a round window-related cochleostomy either with or without a bony partition. Blind drilling procedures on the convexity of the promontory are avoided because this can result in either scala vestibuli access or substantial intracochlear damage.