Difficult Cases: Controversies in Cochlear Implantation David S Haynes, MD FACS Fred F Telischi, MD MEE FACS Lawrence R. Lustig, MD Robert F Labadie, PhD MD Nikolas H Blevins, MD Matthew L. Carlson, MD
CI 2015 Twilight Session Medical Surgical Panel Who is in the Audience? 1. Surgeon 2. Audiology 3. Speech Language Pathology 4. Deaf Educator 5. Research 6. Other
Hearing Preservation
Predictors of CI Performance Subject Variables: Age of onset Age at implantation Duration of deafness Etiology of deafness Hearing aid use Preoperative hearing (speech perception) Cognitive skills Engagement Communication mode Device Variables: Processor type Implant model (minor differences) Electrode geometry Electrode number Duration of implant use Speech processing strategy
Predictors of CI Performance Now: In the Era of Hearing Preservation Surgical Technique Surgical Experience - matters
Predictors of CI Performance Now in an era where Surgical Technique determines potential Cochlear implant performance.
Now in an era where Surgical Technique determines potential Cochlear implant performance. How has this affected your center? How will this affect smaller centers? Referrals?
Hearing preservation doesn t matter because The hearing is useless anyway. My patients do well, why change?. Hearing Preservation Surgery takes more time... and it s more difficult and time is money. Patients will lose hearing over time, anyway. The electrical signal from the CI overpowers the cochlea anyway, it is of no benefit Saving hearing does not improve implant performance We are setting ourselves up for failure
Perioperative Steroids When to start? How much? What type? How long? Intratympanic?
Round Window Vs. Cochleostomy?
Round Window Insertion Type of Incision Allow egress of CSF?
Insertion Speeds: How slow is slow?
Intracochlear Injury During CI Acute direct mechanical trauma from electrode insertion or hydraulic forces Fracturing of osseous spiral lamina containing dendrite processes Injury to the modiolus (containing spiral ganglion cells) located along the medial scala tympani wall Compression or tearing of superficial arterial supply or draining venous systems Damage to the lateral wall (containing spiral ligament, organ of Corti, and stria vascularis) Misdirection of electrode into the scala media or scala vestibuli Acute non-mechanical injuries Acoustic trauma from drilling Disruption of labyrinthine fluid homeostasis through excessive suctioning of perilympthatic fluid, introduction of blood into the scala tympani, and mixing of endo and perilymphatic fluids Subacute or delayed deleterious events Bacterial labyrinthitis from spread of middle ear flora into cochlea Foreign body reaction to electrode Reactive fibrosis and/or ossification (resulting from mechanical trauma, bacterial infection, foreign body reaction, introduction of bone dust into cochleostomy) Molecular activation of pro-apoptosis and necrosis pathways resulting in delayed neural injury
Prevention of Intracochlear Injury What is the most critical cause of injury?
Surgical check list: q Meningitis vaccination q Audiometric testing q CT/MRI scans q Antibiotics q Device Type/back up q Etc.. q Cochlear Duct Length???
How do you measure Cochlear Duct length?
What Electrode would you use? 35mm,? 41mm CDL DOB: December 19, 1955
Prevention of intracochlear injury Surgical technique Complete all bone and soft tissue work before cochleostomy Meticulous hemostasis Avoid bone dust entry into cochlea Small strategic cochleostomy (1 mm anteroinferior) vs. Round Window Minimal to no suctioning of perilymph Short interval between cochleostomy and insertion (place/fix device first)
Prevention of intracochlear injury I ve done a lot of Hearing Preservation Cochlear Implants, and I have learned a great deal. The most important thing to do in the operating room is..
I saved residual hearing but they lost hearing during activation. What about loss during intraoperative testing?
Would anyone do a bilateral Simultaneous CI?
I put in a short electrode and they lost hearing, they did not do well so I put in a long one and they are doing great Explain?
Case 1 Implant placed 1989 Device failure wants reimplant CT : unremarkable Upon removal of existing device: difficult!
Case 1 What to Do? Dummy devices Multiple electrodes ready (even with nl CT) Which ones Thin? Firm? Short? Drill basal turn? How?
Case 2 Neurofibromatosis Type II
AUGUST 2013 Right CPA mass: 2.6 X 1.4 cm Left CPA mass: 2.1 X 0.7
1 year later- OCTOBER 2014 Right CPA mass: 2.9 X 1.6 cm Left CPA mass: 2.2 X 0.7
1 year la SEPTEMBER 2015 Right CPA mass: 3.1 X 2.6 cm Left CPA mass: 2.2 X 0.7
Case 3 Congenital Malformation
What Electrode would you use? DOB: January 6, 1976
CI 2015 Twilight Session Medical Surgical Panel Which Device Would you use? 1. MED EL Flex 24 2. MED EL Flex 28 3. MED El Standard (31mm) 4. Nucleus Hybrid 5. Nucleus 522 6. Nucleus Contour 7. ABC Mid-Scala 8. ABC 1J
Multiple electrodes in surgery Back up devices, different? Full array in the OR?
What Electrode would you use? DOB: April 29, 1950
CI 2015 Twilight Session Medical Surgical Panel Which Device Would you use? 1. MED EL Flex 24 2. MED EL Flex 28 3. MED El Standard (31mm) 4. Nucleus Hybrid 5. Nucleus 522 6. Nucleus Contour 7. ABC Mid-Scala 8. ABC 1J
Which side/electrode would you implant? DOB: September 4, 1924
What Electrode would you use? DOB: September 11, 1946
CI 2015 Twilight Session Medical Surgical Panel Which Device Would you use? 1. MED EL Flex 24 2. MED EL Flex 28 3. MED El Standard (31mm) 4. Nucleus Hybrid 5. Nucleus 522 6. Nucleus Contour 7. ABC Mid-Scala 8. ABC 1J
Thank You