Cochlear implant surgery
Anesthesia type General
Airway ETT
Lines and access PIV
Monitors Standard; facial nerve monitoring
Primary anesthetic considerations
Preoperative Patients' hearing is limited
Intraoperative Facial nerve monitoring (avoid paralytics)
Postoperative

Cochlear implant surgery is a novel surgical approach to address deafness and sensorineural hearing loss. The surgery consists of implanting a cochlear implant device that resides externally and receives and processes sound, and an internal component that transmits the received sound and stimulates the cochlear nerve[1][2]. This surgery has been applied to post-lingual adults and prelingual children with hearing loss. Typically, during surgery, a 2-channel electrode is used to monitor the upper and lower divisions of the facial nerve. The classical approach is a posterior tympanotomy - used both for adults and children. Surgical incision is postauricular and that the cochlear implant device sits internally under the skin behind the incision usually. There is no external mechanical component of the device on the surface of the skin that can be seen immediately post-op. A suprameatal approach is reserved for patients with anatomical variations (16%).

Preoperative management

Patient evaluation

  • Patients' limited hearing may impair preoperative consultation
  • Investigate genetic/syndromic sources of hearing loss such as neurofibromatosis it's multi-organ pathology

Operating room setup

  • Standard GA setup
  • Consider straight connector with accordion to ETT
  • Circuit extensions for 180-degree supine position


Intraoperative management

Monitoring and access

  • Facial nerve monitoring
  • PIV (consider 2nd IV in lower extremity with 180-degree positioning)

Induction and airway management

  • GETA

Positioning

  • 180-degree turn (head is away from anesthesia team)
  • Head positioned away from operating site.
  • Surgeons may conduct frequent head position changes intraoperatively
  • Surgeons frequently tilt table for adequate visualization under the microscope. Patients must be carefully strapped to table during these extreme table-tilt angles. Consider 3-4 safety straps during initial positioning

Maintenance and surgical considerations

  • Avoid paralytics to maintain facial nerve monitoring. Consider high-depth of anesthesia or remifentanil infusion
  • During microscopy, minimize patient movement
  • Volatile anesthetics are appropriate despite facial nerve monitoring

Emergence

Postoperative management

Disposition

  • PACU
  • Home discharge

Post-op considerations

  • Patient hearing is still impaired post-op. Patients must wait weeks before external sound sensor is activated and the patient can hear
  • Glasscock pressure dressing[3] remains on the patient for 2 days post-op
  • Eye and lip sites from facial nerve monitor needles may cause oozing of blood or bruising

Pain management

  • Oral narcotics
  • Multi-modal, non-narcotic medications

Potential complications

  • PONV

Procedure variants[4]

Posterior

Tympanotomy

Suprameatal
Unique considerations Positioning of the device

via the external auditory canal

Position
Surgical time 180min 43min
EBL
Postoperative disposition
Pain management
Potential complications Facial nerve damage (1%)[4]

References

  1. Naples, James G.; Ruckenstein, Michael J. (2020). "Cochlear Implant". Otolaryngologic Clinics of North America. 53 (1): 87–102. doi:10.1016/j.otc.2019.09.004. ISSN 1557-8259. PMID 31677740.
  2. Mowry, Sarah E.; Woodson, Erika (2020-01-01). "Cochlear Implant Surgery". JAMA otolaryngology-- head & neck surgery. 146 (1): 92. doi:10.1001/jamaoto.2019.2274. ISSN 2168-619X. PMID 31556929.
  3. Levy, Joshua M.; Johnson, Bradley T.; Molony, Timothy B. (2011). "Effectiveness of the Glasscock dressing compared to the mastoid pressure dressing in cochlear implantation". The Laryngoscope. 121 (S5): S323–S323. doi:10.1002/lary.22279.
  4. 4.0 4.1 Xu, Bai-Cheng; Wang, Su-Yang; Liu, Xiao-Wen; Yang, Ke-Hu; Zhu, Yi-Ming; Chen, Xing-Jian; Du, Wan; Li, Yong; Chen, Chi; Guo, Yu-Fen (2014). "Comparison of Complications of the Suprameatal Approach and Mastoidectomy with Posterior Tympanotomy Approach in Cochlear Implantation: A Meta-Analysis". ORL. 76 (1): 25–35. doi:10.1159/000358922. ISSN 0301-1569.