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

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).

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.

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.

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.