Cochlear Implantation at King Abdullaziz University Hospital, Riyadh: A Multisystem Prgram, ( )

Introduction  The KAUH Cochlear Implant Program started To date,96 cases have been implanted. Among those, 79 Nucleus, 11 Med-El and 6 Advanced bionics. All are long multi channel cochlear implants.

Candidates Selection  All the patients included in the program had bilateral profound hearing loss with monosyllabic word score of no more than 10% in best aided condition. Their general health was good. They were psychologically stable, with realistic expectation and they are willing to participate in post operative testing and rehabilitation.

Candidates Selection  Radiologic examination (CT,±MRI ) revealed patent cochlea and intact cochlear nerve in all cases. There were no outer or middle ear pathologies that may interfere with surgery.

Candidates selection  Out of all, there were 3 patients with CSOM.  During surgery there were (11) cases with different degrees of ? cochlear ossifications,? rotated cochleae, which were not discovered radiologically.

Evaluation Procedure  Evaluation Intervals: Preoperative evaluation with hearing aids and postoperative evaluation following initial stimulation with cochlear implant, then 3, 6 and 12 months postoperativly.

Hearing thresholds  Sound field warble tone thresholds for frequencies ranging from 250 Hz t Hz were measured pre- and post- operatively, with the hearing aid and cochlear implant.

Speech perception tests  Evaluations were done in a calibrated free field, sound treated booth with the subject using their hearing aids before surgery at 70 – 80 dB SPL via a loudspeaker. Evaluations were done in monaural or binaural listening conditions before surgery. After surgery, monaural implant evaluations were performed.

Speech evaluation for children Preoperative and postoperative evaluation include:  Lip-reading test.  Listening Progress Profile.  Receptive Language Skill test.  Expressive Language Skill test.

Speech evaluation for adults  Minimal Auditory Capability test. (MAC )

Surgical Principles  Incision: Extended endaural(67cases) Minimal invasive ( 29cases )

Skin Incision 1 cm 3-4 cm

Pericranial Flap 1 cm Original Incision Line 1 cm

Surgery

Surgical Procedure

Results  A total number of 96 patients who met the criteria for implantation were implanted.  These were divided into 4 groups according to the type of implant used.

Summary of implanted groups PeriodSpeech strategyChannelsElectrodeCasesGroup SPEAK,CIS22Long 17mm 14 Nucleus SPEAK,CIS& ACE 22Long 22mm 65 Nucleus CIS& NofM12Long 31mm 11 Med-El SAS& CIS16Long 23mm 6 Advanced bionics

Demographic findings in different groups Group 4Group 3Group 2Group 1 Advanced bionicsMed-ElNucleus 24Nucleus-22Implant Number Age: children adult Sex: male female O 14 Speech: Pre. Post Side: Rt Lt Tilted cochlea(2) ? ossification Explanted (1) Dizziness (1) Ossification(1) Explanted (1) Dizziness (3) Facial (1) Infection(3) Ossification(7) Gush (2) Reimplanted(2) Explanted (1) Thick skin (1) Dizziness (1) Gush (1) Complications& follow up

Results  Among the 96 implanted patients there were 33 post-lingual and 63 pre-lingual cases.  The mean age of pre-lingual patients was 3 years & 6 months.

Results  Out of 96 implanted cases we met 11 cases with different degrees of cochlear ossifications. All were implanted either partially or through scala vestibuli.

Results We met the following conditions either intra, or post-operative.  1 case of facial paralysis.(recovered in 3 months )  3 cases of lymphatic leak.  6 cases of incomplete insertion(2-5 electrodes out).  3 cases of wound infection.  1 case of thick skin over the implant  5 cases of post operative dizziness for few days.  3 explanted cases.  2 reimplanted cases.

Results

3 Explanted cases  Tow of them explanted after recurrent otitis media, ear discharge and device failure.  The third explanted after unexplained sever headache and tinnitus.

2 Reimplanted cases  Tow cases were reimplanted after incomplete insertion and torsion of the electrode.  No response was found.  They performed well after reimplantation.

Audiological Results  Pure-tone audiograms, measured before surgery and 6 months after surgery, showed improvement of free field tone threshold for all subjects in our program. The average gain in hearing was 40 dB. No statistical difference was found between groups of implants.

Audiological Results  Comparison between mean pure tone average at different frequencies before implantation and after getting stable map Hz 4000 Hz 2000 Hz 1000 Hz 500 Hz Frequ ency in Hz 100dB 95dB90dB70dBBefore 40dB45dB40dB 35dBAfter

Mean Pure Tone average before & after implantation

Listening progress profile  In a prospective longitudinal study of 21 pre-lingual children with age range from 3 to 7 years, a rapid marked improvement in the detection of sound and speech was evident at 6 months post implantation. At 36 months post implantation they reached the maximum score available in our test (LIP test).

Difficulties Faced  Program support and sponsorship.  Follow up cases outside Riyadh.  Varient family expectation and support.  Implanted cases outside our program that asking for support.