Image-guided protocol with a guide-marker for bone conduction hearing implant placement estimation

OBJECTIVE: To propose a protocol for image-guided implant placement estimation, combining 3D reconstruction of preoperative Computed Tomography (CT) images and a guide-marker, for individuals undergoing percutaneous Bone Conduction Hearing Devices (BCHD). METHODS: Fifty-one subjects aged 6- to 75-years undergoing percutaneous BCHD surgery were included. Three optional implant points were estimated and marked using a guide-marker, and compared with preoperative CT images to define optimal placement. A peer validation was conducted by two independent reviewers to assess the replicability of the protocol in clinical practice. RESULTS: Bilateral CT images were obtained from all 51 subjects, and a total of 54 BCHD surgeries were performed. Relevant findings, including mastoid cells (19.6%), cranial suture lines (27.5%), perforating vessels (13.7%), bone surface irregularities (1.9%), venous lakes (9.8%), and fixation plates (3.9%) were identified in 52.9% of subjects, and they affected the implant placement in 37.3% of cases. There was moderate agreement between the reviewers regarding implant placement in both right and left ears, and in relation to the actual implant placement performed during the surgical procedure. CONCLUSION: The image-guided implant placement estimation, combining 3D reconstruction of preoperative Computed Tomography (CT) images and a guide-marker, has proven reliable and effective for estimating optimal implant placement in subjects undergoing percutaneous BCHD surgery, thereby constituting a valuable tool for clinical practice.