Endoscopic Visualization of The Round Window Niche: Developing Skills for Cochlear Implants

By June 7, 2019

Stipech, Guillermo1; Reyes, Joaquín2; Prieu, Fernando3; Haeffeli, Ignacio3
1 Otología Endoscópica Argentina, Mendoza, Argentina
2 Hospital Univalle, Cochabamba, Bolivia
3 Hospital Iturraspe, Santa Fe, Argentina

The goal of this study was to analyze the endoscopic visualization of the round window niche to improve skills for endoscopic cochlear implant surgery.

– Study Design: 
Prospective case review
– Setting: Tertiary referral center
– Patients: First stage group: 72 patients undergoing endoscopic transcanal approach, excluded cases were bone drilling was needed or neoplasm. Second stage group: 13 patients undergoing cochlear implant surgery.
– Intervention: Analyze the anatomy of the RW niche as part of an action plan for developing skills for cochlear implant surgery. Then performing endoscopic cochlear implants by a combined approach.

– Main Outcome Measure(s): 
Visualization from the external auditory canal of the round window niche, identification of the fustis and subchoclear canal, anatomical variations, and bleeding complications.
– Results: The RW niche was visible in 66 patients. 2 cases the RW niche was partially hidden by the jugular bulb. 3 cases the RW niche was covered by constant bleeding from the middle ear mucosa or timpanomeatal flap, 2 cases the RW was completely covered by bone,  1 case had a bone bridge over the RW,  The fusits was visible in 52 patients and the subcochlear canal in 22. Then, 13 patients were successfully implanted, full insertion of electrodes (100%).

As part of an action plan for developing skills for cochlear implant surgery routinely analyzing the round window niche in every endoscopic ear surgery is highly recommended. We were able to comprehend the anatomy of the round window, identify our weaknesses and identify anatomical abnormalities. When the time comes to perform cochlear implants, the surgeries were achieved successfully and with confidence.