Post-operative radiological evaluation of a bilateral hypoglossal nerve stimulation system.

INTRODUCTION: Hypoglossus stimulation implants are a second-line option for the treatment of obstructive sleep apnea (OSA). Similar to other implants, postoperative positional evaluation serves as a quality control measure for the surgical procedure and as a reference for future adjustments. Furthermore, the impact of artifacts on the assessment of the adjacent structures might be of clinical importance. This study aimed to evaluate postoperative radiological positional implant control and artifacts of a bilateral hypoglossal nerve stimulation device. MATERIAL AND METHODS: We retrospectively evaluated radiological imaging of 11 patients on the first day after implantation of a bilateral nervus hypoglossus stimulation device. A variety of radiological imaging procedures were utilized: 8 CT scans (in sagittal and axial planes) and 11 x-ray examinations. Radiological imaging was analyzed regarding the position of the implant, anatomy, and artifacts. The age range of patients varied from 59 to 87 years (mean 69.1 years; SD 9.1 years). RESULTS: Evaluation of x-ray images did not reveal artifacts that affected the diagnostic accuracy of postoperative position control. In contrast, CT images showed artifacts in the coronal, sagittal, and axial planes, making radiological assessment more difficult. We observed a variation of device position without any effect on functionality. Defined paddle symmetry was found in 8 out of 11 cases. CONCLUSION: Postoperative radiologic monitoring of a bilateral hypoglossal nerve stimulator is recommended. A variation of device position could be found.