Cochlear Implantation with a Slim,

Modiolar Array

Jonathan L. McJunkin, MDNedim Durakovic, MD Jacques Herzog, MD Cameron C. Wick, MD Craig A. Buchman, MD

• Craig Buchman, MD– Consultant for Cochlear Americas, Advanced Bionics, and MedEl

– Equity interest in Advanced Cochlear Diagnostics, LLC.

• Jacques Herzog, MD– Consultant for Cochlear Americas

• Jonathan McJunkin, MD– Consultant for Cochlear Americas

• Cameron Wick, MD– Consultant for Stryker Corporation

Disclosures

• Various factors found to influence cochlear implant(CI)

outcomes– Patient-related: age, hearing loss duration, comorbidity, cognition

– Device-related: full scala tympani insertion, modiolar proximity

• Cochlear© Slim, Modiolar Electrode(CI 532)

– Precurved(perimodiolar) array inserted with a

sheath(slimmer profile)

– Designed to combine advantages of lateral

wall(atraumatic) and perimodiolar(precurved) arrays

Background

• Describe CI 532 surgical outcomes in multi-institutional setting

– Surgical experience/insight

– Electrode location

– Hearing preservation

– Complications and adverse events

Objectives

• Setting: Multi-institutional

• Population: 100 Adult(>18 yo) CI candidates

• Design: Nonrandomized, single-subject, repeated-measures

in which each subject serves as his/her own control

• Intervention: CI 532 placement

– Postauricular approach with cochleostomy approach per surgeon

– Intraoperative X ray to check for tip rollover

Study Design

• Surgical Questionnaire– Completed on day of surgery

• Electrode Position– Postoperative CT reconstruction to locate electrode array

• Scalar location of each electrode contact

• Insertion Depth

• Wrapping Factor: measure of mediolateral position of array

• Hearing Preservation– Low frequency Pure Tone Average(125, 250, 500 Hz) in implant ear alone

Methods

• 100 patients implanted January 2017 to April 2018• 13 sites with 25 surgeons

– Range of CIs per surgeon: 1-14(median 4)• Mean Age at time of CI: 67 yrs

– Range 23-93 yo• Mean Duration of severe to profound hearing loss: 7.8 years

– Range 0-19 years

Results- Demographics

• Questionairre completed in all cases

• Full Insertion in all cases

• Cochleostomy Approach– 61% Extended Round Window(ERW)

– 29% Round Window(RW)

– 10% Separate Cochleostomy(C)

– Cochleostomy Approach modified in 8% of cases: RW converted to ERW

• 80% reported “easy to handle and easy to insert.”– 14 cases with issues related to electrode(n=3), sheath(n=9) or both(n=2)

– 1 tip rollover identified intraoperatively- reloaded, reinserted, verified

Results – Questionairre

Surgical Pearls

• Check array deployment angle relative to sheath prior to insertion• Sheath fin oriented towards lateral semicircular canal• Round window insertion(less traumatic?) vs. ERW(more consistent

ease of sheath insertion)• Sheath insertion with hand opposite of surgical ear

– One hand only for sheath insertion(Debakey forceps)– Right hand for left ear– Left hand for right ear

• If any difficulty with initial sheath insertion- may require modification with either RW disarticulation or ERW approach

• Smooth sheath insertion= smooth array insertion

• CT reconstructions in 92% (92/100) of patients

• Scalar Location– 89% (82/92) full ST insertion

– 7.6% (7/92) translocation(ST to SV)

– 3.3% (3/92) full SV insertion

• Wrapping Factor(WF)

– Mean 59.5% (Range 49.7-82.3; SD 4.53)

• Insertion Angle

– Mean 404 degrees (Range 259-494; SD 39.7)

Results – Electrode PositionWF = 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿 𝑎𝑎𝑎𝑎𝑎𝑎𝐿𝐿𝐿𝐿 𝐿𝐿𝑎𝑎𝐿𝐿𝑒𝑒𝐿𝐿𝑒𝑒𝑎𝑎𝑒𝑒𝐿𝐿

𝐿𝐿𝑎𝑎𝐿𝐿𝐿𝐿𝑒𝑒𝑎𝑎𝑎𝑎 𝑊𝑊𝑎𝑎𝑎𝑎𝑎𝑎 𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿𝐿

Holden et al. Factors affecting open-set word recognition in adults with cochlear implants. Ear and Hearing. 2013; 34:342-60.

• 2 tip rollovers identified on postoperative CT reconstruction

Results- Tip Rollovers

- Plain film(left) and CT reconstruction after revision surgery- Array visualization improved

- Plain film(left) and CT reconstruction of tip rollover- Review of plain films revealed poor visualization of array

Complications/Adverse Events

• Turn head approximately 50 degrees from midline with implant side facing up.

• Imaging beam should be directed in a transorbital plane.

• If initial image is unclear, “over-penetrate” on repeat capture for better electrode visualization.

Intraoperative X ray for CI

Svrakic, M., Friedmann, D. R., Berman, P. M., Davis, A. J., Roland, J. T., & Svirsky, M. A. (2015). Measurement of Cochlear Implant Electrode Position From Intraoperative Post-insertion Skull Radiographs: A Validation Study. Otology & Neurotology : 36(9), 1486–1491.

Hearing Preservation(LF-PTA≤80 dB)

• Preoperative : 80% (77/96)• Activation: 44% (34/77)• 1 month: 40% (31/77)• 3 months: 39% (30/77)• 6 months: 35% (27/77)

• CI 532 array demonstrates perimodiolar placement and low rate

of scalar translocation meeting design goals

• Intraoperative Xray imperative to identify tip rollover

• Hearing preservation possible but difficult to draw conclusion in

this population of traditional CI candidates

Conclusions

• 13 participating centers– University of California, San Francisco, California – Rocky Mountain Ear Center, Englewood, Colorado – University of Iowa, Iowa City, Iowa – University of Michigan, Ann Arbor, Michigan– Midwest Ear Institute, Kansas City, Missouri– New York University, New York, New York– The Ohio State University, Columbus, Ohio– Hearts for Hearing, Oklahoma City, Oklahoma– Dallas Ear Institute, Dallas, Texas– Ear Medical Group, San Antonio, Texas– Spokane ENT, Spokane, Washington– The Center for Hearing and Balance Disorders, Chesterfield, Missouri– Washington University, Saint Louis, Missouri

Acknowledgements