A practical, single-view alternative to Stenver's for plain radiographic unilateral and bilateral post-cochlear implant position check

Abstract

Introduction: ‘Stenver's’ is the standard plain radiograph view to check the electrode position after cochlear implantation. However, a reproducible alignment for intra-individual comparison of electrode position using a true Stenver's alignment is not always straightforward to achieve, particularly for inexperienced radiographers, or on non-compliant children. In addition, two ionizing exposures in two different positions are required for bilateral cochlear implants.

Aims: To assess the efficacy of other, more simple, single-exposure radiographs for the assessment of electrode position.

Methods: Dummy electrodes and receiver units were bilaterally implanted into a cadaver. Plain radiographs in Stenver's views, and plain antero-posterior (AP) midline radiographic single views incorporating both implants were obtained with the tube at a range of angles tilted caudal and cranial to the perpendicular. Five internationally renowned cochlear implant surgeons were each asked if each radiograph gave adequate information for unilateral and for bilateral implants and they were asked to list in order of their favoured top three views.

Results: No surgeon thought that a single-exposure Stenver's view was adequate for assessment of the contra-lateral side. Consensus was that all AP views were fit for the purpose, with no preference given between each of the AP views. The ipsi-lateral Stenver's was considered to give better depth of insertion information.

Conclusion: There is no apparent advantage of caudal and cranial tilt angles over a straight perpendicular AP. A single-view AP radiograph is an alternative to Stenver's view for a post-unilateral and post-simultaneous bilateral cochlear implant check.

Keywords:

• Cochlear implant
• Radiology

Acknowledgements

We would like to thank Cochlear Ltd for providing the dummy devices and the participating panel of surgeons.