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Cochlear implantation dr utkal

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Cochlear implantation dr utkal

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This slide is all about cochlear implantation concisely. I have depicted the surgical steps by pictures. Enjoy guys.

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  1. 1. Cochlear Implantation Dr. UtkalMishra 2nd Yr. PG (ENT)
  2. 2. INTRODUCTION Cochlear implants are the 1st true bionic sense organs. It is surgically implanted in the inner ear and activated by a device worn behind the ear. Cochlear Implants are not hearing aids. The Fundamental Concept of Cochlear Implant is to bypass the damaged hair cells. The device bypasses damaged parts of the auditory system and directly stimulates the nerve of hearing, allowing individuals who are profoundly deaf to receive sound.
  3. 3. HISTORY 1800 – Alexandro Volta - electrical stimulation to metal rods inserted in his ear canal created an auditory sensation . 1957 – Djourno & Eyeries – stimulated auditory nerve directly with current & the patient reported a clear auditory percept. 1961 – House & Doyle – put electrodes in scala tympani of 2 profoundly deaf adults & get a clear auditory response 1972 – First single channel cochlear implant developed. 1984 – Cochlear Corporation introduced the first ever Multichannel Cochlear Implant System called “NUCLEUS 22” 1976 Wednesday 22 September - The first cochlear implant took place at Saint-Antoine hospital, Paris. It was performed by CH Chouard & assisted by Bernard Meyer.
  4. 4. PARTS OF COCHLEAR IMPLANT EXTERNAL PART – 1. Microphone 2. Speech processor 3. Transmitter INTERNAL PART – 1. Receiver – Stimulator 2. Electrode Array
  5. 5. EXTERNAL PART MICROPHONE SPEECH PROCESSOR TRANSMITTER
  6. 6. INTERNAL PART MAGNET ANTENNA STIMULATOR ELECTRODE
  7. 7. TYPES OF COCHLEAR IMPLANT 3 Types :- 1. NUCLEUS 24 FREEDOM by Cochlear Corporation 2. HI RES 90K by Advanced Bionics 3. PULSAR by Med El
  8. 8. NUCLEUS 24 FREEDOM
  9. 9. HI RES 90K
  10. 10. MED EL PULSAR
  11. 11. COCHLEAR IMPLANT CANDIDATES Each cochlear implant system is shipped with a “Physician's Package Insert” which specifies the FDA labeled indications for implantation. Since the three cochlear implant manufacturers generally work independently, the labeled indications for cochlear implant criteria vary across the companies.
  12. 12. ADULT Age – More than 18 yrs Bilateral severe to profound Sensorineural hearing loss. Both Advanced Bionics and Med El - severe-to-profound Cochlear Corporation - moderate-to-profound Must be Postlingual Deaf Little or no benefit from hearing aids. Inner ears must be surgically able to accept the device Must not have any chronic illness A deaf adult who never learned to speak does not benefit from a cochlear implant.
  13. 13. AUDIOMETRIC CRITERIA Gone are the days when cochlear implantation is done only in hearing loss above 90 dB
  14. 14. SPEECH RECOGNITION Sentence recognition testing is done in best aided condition at 60 dB SPL FDA approved sentence lists used are – 1. BKB – SIN sentences in Noise & Quiet 2. Az -Bio sentences 3. CNC monosyllabic words Maximum score for cochlear implant candidacy varies Advanced Bionics – 50 % Cochlear Corporation – 60 % Med El – 40 %
  15. 15. PEDIATRIC Age – More than 12 months Bilateral profound sensorineural hearing loss > 90 dB No benefit at all with the most optimized hearing aid. Inner Ear surgically accesible in CT scan Auditory nerve present in MRI Post lingual profound deafness caused by meningitis is not a good candidate for cochlear implant. – neoosteogenesis causing cochlear duct obliteration.
  16. 16. AGE 12 – 24 months Bilateral profound sensorineural hearing loss Trial of hearing aids for 3 months - should make at least 3 months of progress in auditory skills and speech/language development. The evaluation of auditory skills and progress for children aged birth to 2 years is not achieved by simply looking at the audiogram. Auditory skills are generally assessed via parental history and administration of validated questionnaires designed to gauge auditory-based responsiveness to speech and sounds in a child's environment.
  17. 17. QUESTIONNAIRE IT-MAIS – Infant Toddler version of meaningful Auditory Integration Scale (Commonest) FAPCI - 23-item Functioning after Pediatric Cochlear Implantation 35-item Little Ears auditory questionnaire PEACH - Parents' Evaluation of Aural/Oral Performance in Children
  18. 18. OLDER CHILDREN The determination of cochlear implant candidacy for older children is generally based upon either mono- or multi-syllabic word recognition by Early Speech Perception Test Multisyllabic Lexical Neighbourhood test HINT Sentences for children < 30 %
  19. 19. WHICH EAR TO IMPLANT Better hearing ear Most recently deaf ear Least obstructed labyrinth In traumatic hearing loss the ear with reduced labyrinth function chosen
  20. 20. Electroacoustic / Hybrid Implant Combine a cochlear implant with hearing aid. Indication – Individuals with profound high frequency loss with retained low frequency hearing CI – Stimulates basal turn >> High Frequency Hearing aid amplifies low frequency
  21. 21. DEVICE SELECTION Aesthetic looks Coding Strategy Electrode arrays – 1. Compressed array 2. Double array
  22. 22. CODING STRATEGY A speech coding strategy defines the method by which pitch, loudness & timing of sound is translated into series of impulses. 2 types – 1. Simultaneous (Only AB) 2. Non simultaneous
  23. 23. SIMULTANEOUS STRATEGY Activation of more than one electrode at same time. Provide a more natural quality of sound Only Advanced Bionics is capable of SS. Disadvantage- When 2 electrodes are activated simultaneously there is chance of signal interference. So Modiolus Hugging Electrodes are developed – lies close to spiral ganglion so less intensity sound is required for activation hence less interference.
  24. 24. MODIOLUS HUGGING ELECTRODE Self coiling electrode array with memory. Comes with a stylete which keeps the electrode straight during insertion As it uses low intensity signals – Extended Battery Life
  25. 25. Electrode 1 Electrode 2 Channel interaction IncreasedDistance
  26. 26. Spiral Ganglion cells Electrode 1 Electrode 2 Activated CellsActivated Cells
  27. 27. PRE-OP EVALUATION 1. AUDIOLOGICAL – PTA Speech audiometry Aided audiometry BERA Promontory Stimulation Test OAE 2. RADIOLOGICAL – HRCT – Cochlear Hypoplasia IAC MRI – Early Labyrinthitis Ossificans Postmeningitic Endocochlear Obstruction Absent Cochlear Nerve
  28. 28. SURGICAL PROCEDURE
  29. 29. CONSIDERATIONS Can be done as outpatient or inpatient. Can be done under GA or LA. IV antibiotics should be given at least 20 minutes before skin incision. Surgery duration – 3 -5 hrs Duration of stay in Hospital – 2 days 3 to 4 weeks later – Programming of device
  30. 30. INCISION & SKIN FLAP Inverted – J shaped incision. Incision should not cross the edges of device Flap elevated in 2 layers Periosteum of mastoid is elevated as an anteriorly based Palva flap. Skin thickness over implanted stimulator should be less than 6.0 mm
  31. 31. THE WELL A portion of skull as flat as possible selected for the placement of stimulator minm. 15mm postr. to EAC. Surgical drill used to create a defect in the skull contoured exactly to fit the stimulator A channel is also formed for the passage of electrodes to mastoid cavity. Tie down holes are drilled around the well. Dangerous !!! Device is fixed with sutures in the well.
  32. 32. MASTOIDECTOMY The cavity should not be saucerized. Edges should be left as acute as possible to retain the electrodes within its confine. Facial recess identified & posterior tympanotomy done. If facial recess seems unusually large – Facial N. anomaly suspected – Be ready for a cochlear anomaly also !!!
  33. 33. COCHLEOSTOMY Remove the anterior lip of round window niche. Apply Lubricant – “Healon” or “Provisc” The electrode array is inserted as atraumatically as possible with its tip directed inferiorly. Cochleostomy sealed with a small piece of soft tissue.
  34. 34. CLOSURE Three layered wound closure done – Palva flap closed tightly with interrupted absorbable sutures Superficial flap closed with burying interrupted sutures Skin closed with Subcuticular sutures.
  35. 35. POST OP COMPLICATIONS
  36. 36. EARLY Facial N. Injury Alteration of Taste Infection Wound dehiscnce / Flap Necrosis Early Device Failure CSF Leak
  37. 37. WOUND DEHISCENCE / FLAP NECROSIS Wound dehiscence occurs commonly in an active child. If small – leave as such to heal by secondary intension If large – Secondary closure in OT Flap Necrosis occurs due to aggressive thining of flap – most serious complication & require device removal.
  38. 38. CSF LEAK Occurs frequently at the time of drilling tie down holes. Can also occur after opening of scala tympani in case of – modiolar defect. / Common cavity deformity. GUSHERS Controlled by packing the common cavity with muscle. If still not controlled – Ear is closed by plugging the eustachian tube, filling the middle ear & mastoid with fat and oversewing the Extn. Auditory canal.
  39. 39. LATE Extrusion / Exposure of Device Pain Displacement of Electrodes Late device failure Otitis Media Meningitis
  40. 40. MENINGITIS Cochlear implantation recipients are at high risk of developing Pneumococcal Meningitis. Center for Disease Control made it mandatory for pneumococcal vaccination as follows - All children < 1 yr. must receive 3 doses of Pneumococcal Conjugate (PEVNAR) vaccine. Cochlear implant child > 2 yr who have received PEVNAR should receive one dose dose of pneumococcal polysacharide vaccine. Cochlear Implant child > 5yr should receive one dose of pneumococcal polysaccharide vaccine.
  41. 41. DEVICE ACTIVATION
  42. 42. PROCESS After 3 -4 weeks post op when the wound is well healed implantee returns to clinic to have the external parts of the device fitted called “HOOK UP” There are 2 types of device stimulation modes – BIPOLAR – each active electrode paired with another intracochlear electrode. MONOPOLAR – It is most preferred mode. Paired with extracochlear electrode.
  43. 43. PROCESS Determination of Threshold level – (minimum) & most comfortable loudness level (maximum) for each electrode Then frequency bands are assigned to each electrode pair by software program. In prelingually deaf child this process is very complicated so recently some objective methods are devised like – Neural Response Telemetry Stapedial reflex estimation Electrical ABR
  44. 44. Now I am ready to answer your Questions !!!

Descrição

This slide is all about cochlear implantation concisely. I have depicted the surgical steps by pictures. Enjoy guys.

Transcrição

  1. 1. Cochlear Implantation Dr. UtkalMishra 2nd Yr. PG (ENT)
  2. 2. INTRODUCTION Cochlear implants are the 1st true bionic sense organs. It is surgically implanted in the inner ear and activated by a device worn behind the ear. Cochlear Implants are not hearing aids. The Fundamental Concept of Cochlear Implant is to bypass the damaged hair cells. The device bypasses damaged parts of the auditory system and directly stimulates the nerve of hearing, allowing individuals who are profoundly deaf to receive sound.
  3. 3. HISTORY 1800 – Alexandro Volta - electrical stimulation to metal rods inserted in his ear canal created an auditory sensation . 1957 – Djourno & Eyeries – stimulated auditory nerve directly with current & the patient reported a clear auditory percept. 1961 – House & Doyle – put electrodes in scala tympani of 2 profoundly deaf adults & get a clear auditory response 1972 – First single channel cochlear implant developed. 1984 – Cochlear Corporation introduced the first ever Multichannel Cochlear Implant System called “NUCLEUS 22” 1976 Wednesday 22 September - The first cochlear implant took place at Saint-Antoine hospital, Paris. It was performed by CH Chouard & assisted by Bernard Meyer.
  4. 4. PARTS OF COCHLEAR IMPLANT EXTERNAL PART – 1. Microphone 2. Speech processor 3. Transmitter INTERNAL PART – 1. Receiver – Stimulator 2. Electrode Array
  5. 5. EXTERNAL PART MICROPHONE SPEECH PROCESSOR TRANSMITTER
  6. 6. INTERNAL PART MAGNET ANTENNA STIMULATOR ELECTRODE
  7. 7. TYPES OF COCHLEAR IMPLANT 3 Types :- 1. NUCLEUS 24 FREEDOM by Cochlear Corporation 2. HI RES 90K by Advanced Bionics 3. PULSAR by Med El
  8. 8. NUCLEUS 24 FREEDOM
  9. 9. HI RES 90K
  10. 10. MED EL PULSAR
  11. 11. COCHLEAR IMPLANT CANDIDATES Each cochlear implant system is shipped with a “Physician's Package Insert” which specifies the FDA labeled indications for implantation. Since the three cochlear implant manufacturers generally work independently, the labeled indications for cochlear implant criteria vary across the companies.
  12. 12. ADULT Age – More than 18 yrs Bilateral severe to profound Sensorineural hearing loss. Both Advanced Bionics and Med El - severe-to-profound Cochlear Corporation - moderate-to-profound Must be Postlingual Deaf Little or no benefit from hearing aids. Inner ears must be surgically able to accept the device Must not have any chronic illness A deaf adult who never learned to speak does not benefit from a cochlear implant.
  13. 13. AUDIOMETRIC CRITERIA Gone are the days when cochlear implantation is done only in hearing loss above 90 dB
  14. 14. SPEECH RECOGNITION Sentence recognition testing is done in best aided condition at 60 dB SPL FDA approved sentence lists used are – 1. BKB – SIN sentences in Noise & Quiet 2. Az -Bio sentences 3. CNC monosyllabic words Maximum score for cochlear implant candidacy varies Advanced Bionics – 50 % Cochlear Corporation – 60 % Med El – 40 %
  15. 15. PEDIATRIC Age – More than 12 months Bilateral profound sensorineural hearing loss > 90 dB No benefit at all with the most optimized hearing aid. Inner Ear surgically accesible in CT scan Auditory nerve present in MRI Post lingual profound deafness caused by meningitis is not a good candidate for cochlear implant. – neoosteogenesis causing cochlear duct obliteration.
  16. 16. AGE 12 – 24 months Bilateral profound sensorineural hearing loss Trial of hearing aids for 3 months - should make at least 3 months of progress in auditory skills and speech/language development. The evaluation of auditory skills and progress for children aged birth to 2 years is not achieved by simply looking at the audiogram. Auditory skills are generally assessed via parental history and administration of validated questionnaires designed to gauge auditory-based responsiveness to speech and sounds in a child's environment.
  17. 17. QUESTIONNAIRE IT-MAIS – Infant Toddler version of meaningful Auditory Integration Scale (Commonest) FAPCI - 23-item Functioning after Pediatric Cochlear Implantation 35-item Little Ears auditory questionnaire PEACH - Parents' Evaluation of Aural/Oral Performance in Children
  18. 18. OLDER CHILDREN The determination of cochlear implant candidacy for older children is generally based upon either mono- or multi-syllabic word recognition by Early Speech Perception Test Multisyllabic Lexical Neighbourhood test HINT Sentences for children < 30 %
  19. 19. WHICH EAR TO IMPLANT Better hearing ear Most recently deaf ear Least obstructed labyrinth In traumatic hearing loss the ear with reduced labyrinth function chosen
  20. 20. Electroacoustic / Hybrid Implant Combine a cochlear implant with hearing aid. Indication – Individuals with profound high frequency loss with retained low frequency hearing CI – Stimulates basal turn >> High Frequency Hearing aid amplifies low frequency
  21. 21. DEVICE SELECTION Aesthetic looks Coding Strategy Electrode arrays – 1. Compressed array 2. Double array
  22. 22. CODING STRATEGY A speech coding strategy defines the method by which pitch, loudness & timing of sound is translated into series of impulses. 2 types – 1. Simultaneous (Only AB) 2. Non simultaneous
  23. 23. SIMULTANEOUS STRATEGY Activation of more than one electrode at same time. Provide a more natural quality of sound Only Advanced Bionics is capable of SS. Disadvantage- When 2 electrodes are activated simultaneously there is chance of signal interference. So Modiolus Hugging Electrodes are developed – lies close to spiral ganglion so less intensity sound is required for activation hence less interference.
  24. 24. MODIOLUS HUGGING ELECTRODE Self coiling electrode array with memory. Comes with a stylete which keeps the electrode straight during insertion As it uses low intensity signals – Extended Battery Life
  25. 25. Electrode 1 Electrode 2 Channel interaction IncreasedDistance
  26. 26. Spiral Ganglion cells Electrode 1 Electrode 2 Activated CellsActivated Cells
  27. 27. PRE-OP EVALUATION 1. AUDIOLOGICAL – PTA Speech audiometry Aided audiometry BERA Promontory Stimulation Test OAE 2. RADIOLOGICAL – HRCT – Cochlear Hypoplasia IAC MRI – Early Labyrinthitis Ossificans Postmeningitic Endocochlear Obstruction Absent Cochlear Nerve
  28. 28. SURGICAL PROCEDURE
  29. 29. CONSIDERATIONS Can be done as outpatient or inpatient. Can be done under GA or LA. IV antibiotics should be given at least 20 minutes before skin incision. Surgery duration – 3 -5 hrs Duration of stay in Hospital – 2 days 3 to 4 weeks later – Programming of device
  30. 30. INCISION & SKIN FLAP Inverted – J shaped incision. Incision should not cross the edges of device Flap elevated in 2 layers Periosteum of mastoid is elevated as an anteriorly based Palva flap. Skin thickness over implanted stimulator should be less than 6.0 mm
  31. 31. THE WELL A portion of skull as flat as possible selected for the placement of stimulator minm. 15mm postr. to EAC. Surgical drill used to create a defect in the skull contoured exactly to fit the stimulator A channel is also formed for the passage of electrodes to mastoid cavity. Tie down holes are drilled around the well. Dangerous !!! Device is fixed with sutures in the well.
  32. 32. MASTOIDECTOMY The cavity should not be saucerized. Edges should be left as acute as possible to retain the electrodes within its confine. Facial recess identified & posterior tympanotomy done. If facial recess seems unusually large – Facial N. anomaly suspected – Be ready for a cochlear anomaly also !!!
  33. 33. COCHLEOSTOMY Remove the anterior lip of round window niche. Apply Lubricant – “Healon” or “Provisc” The electrode array is inserted as atraumatically as possible with its tip directed inferiorly. Cochleostomy sealed with a small piece of soft tissue.
  34. 34. CLOSURE Three layered wound closure done – Palva flap closed tightly with interrupted absorbable sutures Superficial flap closed with burying interrupted sutures Skin closed with Subcuticular sutures.
  35. 35. POST OP COMPLICATIONS
  36. 36. EARLY Facial N. Injury Alteration of Taste Infection Wound dehiscnce / Flap Necrosis Early Device Failure CSF Leak
  37. 37. WOUND DEHISCENCE / FLAP NECROSIS Wound dehiscence occurs commonly in an active child. If small – leave as such to heal by secondary intension If large – Secondary closure in OT Flap Necrosis occurs due to aggressive thining of flap – most serious complication & require device removal.
  38. 38. CSF LEAK Occurs frequently at the time of drilling tie down holes. Can also occur after opening of scala tympani in case of – modiolar defect. / Common cavity deformity. GUSHERS Controlled by packing the common cavity with muscle. If still not controlled – Ear is closed by plugging the eustachian tube, filling the middle ear & mastoid with fat and oversewing the Extn. Auditory canal.
  39. 39. LATE Extrusion / Exposure of Device Pain Displacement of Electrodes Late device failure Otitis Media Meningitis
  40. 40. MENINGITIS Cochlear implantation recipients are at high risk of developing Pneumococcal Meningitis. Center for Disease Control made it mandatory for pneumococcal vaccination as follows - All children < 1 yr. must receive 3 doses of Pneumococcal Conjugate (PEVNAR) vaccine. Cochlear implant child > 2 yr who have received PEVNAR should receive one dose dose of pneumococcal polysacharide vaccine. Cochlear Implant child > 5yr should receive one dose of pneumococcal polysaccharide vaccine.
  41. 41. DEVICE ACTIVATION
  42. 42. PROCESS After 3 -4 weeks post op when the wound is well healed implantee returns to clinic to have the external parts of the device fitted called “HOOK UP” There are 2 types of device stimulation modes – BIPOLAR – each active electrode paired with another intracochlear electrode. MONOPOLAR – It is most preferred mode. Paired with extracochlear electrode.
  43. 43. PROCESS Determination of Threshold level – (minimum) & most comfortable loudness level (maximum) for each electrode Then frequency bands are assigned to each electrode pair by software program. In prelingually deaf child this process is very complicated so recently some objective methods are devised like – Neural Response Telemetry Stapedial reflex estimation Electrical ABR
  44. 44. Now I am ready to answer your Questions !!!

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