Image guidance could aid performance of atraumatic cochlear implantation surgical techniques

It is widely believed that major factors in achieving atraumatic insertion of the electrode array into the cochlea in cochlear implant (CI) surgery include amount of tissue resection, selection of the entry point, and angle of insertion. Our group is interested in developing an image guidance (IG) system for electrode insertion if IG can improve outcomes. Thus, in this work we conducted the first study evaluating whether IG could aid atraumatic electrode insertion. To do this, we measured the performance of experienced surgeons when tasked to perform cochleostomy resection and to select CI insertion trajectories in virtual 3D surgical field-of-view simulation software. This software, which simulates views through the surgical microscope, was designed to allow a user to manually perform cochleostomy resection and to select a preferred insertion trajectory in one of two modes: (a) where the traditional approach is simulated and sub-surface anatomy is not visible; and (b) where an IG approach is simulated and the surgical view is augmented with rendering of subsurface intra-cochlear structures. We used this software to compare two surgeons' performance in selecting insertion trajectories with and without IG. Our results show that when using virtual IG, both surgeons could choose insertion trajectories with less variability, select higher quality insertion trajectories, and create the cochleostomy with substantially less tissue resection. These results suggest that IG could indeed aid performance of atraumatic cochlear implantation techniques.