Robotics for approaches to the mastoid/mastoidectomy

Abstract

It is estimated by the World Health Organization that around 5% of the world's population has some kind of disabling hearing loss that requires rehabilitation (WHO. 2021, https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss). Cochlear implantation is widely regarded as the most effective treatment for patients with severe-to-profound sensorineural hearing loss (Mertens et al. B-ENT, 17(3):155-163; 2021). Since its inception, much research has been devoted to improving the technology of cochlear implants, and the effectiveness and reliability of the devices have improved markedly. However, there has been little research into less invasive ways of placing them. Only since the advent of robotic surgery in general during the past 20 years has robotically assisted cochlear implantation surgery developed. With this technique, unlike the conventional method, it is not necessary to drill away a significant part of the mastoid; one can reach the round window directly with a 1.8-mm and then a 1-mm drill bit, where the electrode can also be placed. The conventional method has the disadvantage that placing the electrode is seldom non-traumatic because of the angle at which the surgeon operates. The advantage of this technique is that it requires little drilling next to the facial nerve, which reduces the risk of facial paralysis. In robotically assisted cochlear implantation surgery there is less space between the drill and the facial nerve, so electrode placement can be more accurate and less traumatic. Here, pre-operative imaging, intra-operative imaging and facial nerve monitoring are of crucial importance. Using pre-operative imaging, one can plan the safest and most efficient drilling trajectory and angles, ensuring atraumatic intra-cochlear electrode array placement. This in turn ensures that the anatomy and physiology of the inner ear are preserved as far as possible, thus reducing the risk of losing the rest of the patient's natural hearing levels. This could lead to a broadening of the indications for cochlear implant placement for patients who do not wish to take this risk (Topsakal et al. Front Neurol. 13, 2022).