Patient selection criteria
Cochlear implantation is mainly used for the treatment of severe or very severe sensorineural hearing loss in both ears.
1. Selection criteria for prelingual deaf patients:
① The implantation age is usually 12 months to 6 years. The smaller the implantation age, the better the effect, but it is necessary to prevent complications such as accidental anesthesia, excessive blood loss, and damage to the inner and outer nerves of the temporal bone. Implantation of cochlear implants is not currently recommended for children younger than 6 months. However, deafness caused by meningitis is at risk of cochlear ossification. It is recommended that surgery be performed as soon as possible under conditions of complete surgery. Children or adolescents over 6 years of age need a certain listening and speaking foundation.
②Severe or very severe sensorineural hearing loss in both ears. After comprehensive audiological evaluation, children with severe hearing loss who wear hearing aids for 3 to 6 months are not effective or have unsatisfactory results. Cochlear implantation should be performed; children with severe hearing loss can consider direct cochlear implantation.
③ There are no contraindications for surgery.
④ The guardian and / or the implanter have a correct understanding and appropriate expectations of the cochlear implant.
⑤ Have the conditions for hearing and speech rehabilitation education.
2. Selection criteria for post-speech deaf patients:
① Post-speech deaf patients of all ages.
② Severe or extremely severe sensorineural hearing loss in both ears cannot rely on hearing aids for normal auditory speech communication.
③ There are no contraindications for surgery.
④ The implanter and / or the guardian have a correct understanding and appropriate expectations of the cochlear implant.
Contraindications to surgery
1. Absolute contraindications: severe malformation of the inner ear, such as Michel malformation; absence or disruption of the auditory nerve; acute purulent inflammation in the middle ear mastoid process
2. Relative contraindications: frequent seizures cannot be controlled; severe mental, intellectual, behavioral, and psychological disorders cannot be combined with auditory speech training.


Excerpt: Cochlear Implant Working Guide (2013)

Minimally invasive cochlear implant surgery

Cochlear implantation of small incisions, cochlear implantation of 2.5-4.0cm small incisions have proven effective, small incisions have been proven to reduce bleeding, shorten the operation time, and basically eliminate the risk of flap necrosis Complications of surgery in young children are of great significance.

Excerpt from: Dai Pu: Some considerations of minimally invasive cochlear implant surgery, Proceedings of the 14th Military Academy of Otolaryngology Head and Neck Surgery


Cochlear Surgery Nursing

Preoperative and postoperative care
Preoperative care
1.1 Psychological Nursing
After the patient is admitted to the hospital, parents or family members need to help them become familiar with the environment (especially children) as soon as possible, and eliminate the fear of the hospital environment.
1.2 Preoperative preparation
Assist doctors to complete various pre-operative examinations of patients; cochlear implantation is a general anesthesia operation. Food and water are forbidden 8 to 12 hours before operation to avoid the risk of aspiration when anesthesia is intubated.
1.3 Preoperative skin preparation
The skin preparation range is 3 ~ 5cm behind the ear, and you can shave your head. After skin preparation, the patient should be instructed to take a bath, especially in children. The cut hair will cause harm to immature skin and need to be cleaned in time.
1.4 Parent Expectation
Before surgery, we must fully understand the benefits and deficiencies of cochlear implants, and we must have appropriate expectations to achieve satisfactory results.
2. Postoperative care
2.1 Nursing after general anesthesia
The supine side should be taken after the operation (both sides are implanted simultaneously and the supine position is used), with the ears facing upwards. Crying and restlessness often occur when the child is awake at the beginning of general anesthesia. Care should be taken to protect the child's safety and prevent falling from bed.
You can eat warm, digestible liquid or semi-liquid diets 4 to 6 hours after surgery, and eat water prematurely. When the child is distressed, it may easily cause the risk of aspiration or asphyxiation.
3. Postoperative guidance
3.1 startup and commissioning
Start up about 1 month after the operation, and arrange the next debugging according to the instructions of the audiologist.
3.2 Postoperative speech rehabilitation training
For children, parents need to send them to professional hearing and speech rehabilitation institutions for rehabilitation training. Language training requires the cooperation of parents. Don't let children see oral pronunciation, sign language, etc. Use oral communication as the first choice.
3.3 Correct use and maintenance of cochlear implants after surgery
Avoid local violent collision and compression, avoid humidity and rain, and prevent external force damage caused by rough operation.


Excerpt: Feng Xiulan, Yuan Chen, Wang Lin'e *, Analysis of perioperative nursing experience in children with cochlear implants. Chinese Journal of Hearing, Speech and Rehabilitation Science, 2009, Issue 5, 73-76

Cases where there is a gap in hearing between the two ears are collectively referred to as Asymmetric Hearing Loss (AHL), which refers to a certain degree of asymmetry in the hearing sensitivity of the ears. An extreme example is that the poor ear is fully deaf and the contralateral ear has normal hearing. Or only mild hearing loss. This extreme example is generally referred to as Unilateral Hearing Loss (UHL) or Single Sided Deafness (SSD). At this time, the frequency of 4 frequencies (ie, 0.5, 1, 2 and 4 kHz) between the ears The asymmetry difference of the pure tone threshold is 30dBHL or more, and at the same time, the poor ear hearing reaches the traditional cochlear implantation standard. Another well-recognized additional condition of UHL is that the average threshold of good ears should be better than 60 dBHL, which makes it clear that it is not suitable to implant cochlear implants on the side of good ears [1].

Based on comprehensive neonatal hearing screening data, the incidence of unilateral deaf children is 1-3% [1] The incidence of unilateral deafness is high in adults, especially in the elderly can be as high as 18% [2]

Causes of unilateral deafness: The causes of unilateral deafness can be hereditary, congenital, and acquired, such as unilateral cochlear nerve dysplasia (Cochlear Nerve Deficiency CND), congenital microtia, large vestibular aqueduct syndrome, Auditory neuropathy, viral / bacterial infectious deafness, unilateral sudden deafness, noise-induced deafness, Meniere's disease, head trauma, unilateral auditory neuroma, etc. [3,4].

Harm of unilateral deafness: Asymmetric hearing loss and speech recognition rate of patients with unilateral deafness will decrease [5], but generally will not seriously affect the speech and language development of patients, and the academic performance of some patients is not directly affected. Patients with lateral hearing loss have not received any intervention throughout their lives [6].

Intervention for unilateral hearing loss: Interventions are recommended for asymmetric hearing loss and unilateral hearing loss. Binaural listening can identify the source of the sound, which can help implanters quickly identify and locate the talker during group communication. Because of unilateral deafness or unilateral cochlear implantation, the speaker's speech cues, such as tones, are weak, so binaural listening is particularly important [7,8].

Chart:

Table 1. Definition of SSD and AHL based on pure tone average hearing threshold [9]

SSD	Poorear	Tosevere hearing loss
	Goodear	≤30dB HL including 4000 Hz
AHL	Poor ear	To severe hearing loss
	Good ear	≥30dB HL including 4000 Hz
		≤60dB HL including 4000 Hz
Hearingasymmetry of both ears	≥30dB HL（poorear PTA4-good ear PTA4)）
PTA4 = Four-frequency pure tone averagethreshold

References:

1. Christophe Vincent, Susan Arndt, Jill B. Firszt, Bernard Fraysse, Pádraig T. Kitterick, Blake C. Papsin, Ad Snik, Paul Van de Heyning, Olivier Deguine, Mathieu Marx: Identification and Evaluation of Co- chlear Implant Candidates with Asymmetrical Hearing Loss. Audiol Neurotol 2015; 20 (suppl 1).

2. Agrawal Y1, Platz EA, Niparko JK: Prevalence of hearing loss and differences by demographic characteristics among US adults: data from the National Health and Nutrition Examination Survey, 1999- 2004. Arch Intern Med. 2008 Jul 28; 168 (14) : 1522-1530.

3. Tharpe AM1, Sladen DP: Causation of permanent unilateral and mild bilateral hearing loss in children. Trends Amplif. 2008 Mar; 12 (1): 17-25.

4. Susan Arndt, Susanne Prosse, Roland Laszig, Thomas Wesarg, Antje Aschendorff, Frederike Hassepass: Cochlear Implantation in Children with Single-Sided Deafness: Does Aetiology and Duration of Deafness Matter Audiol Neurotol 2015; 20 (suppl 1): 21–30 .

5. Lieu JE1, Tye-Murray N, Karzon RK, Piccirillo JF: Unilateral hearing loss is associated with worse speech-language scores in children. Pediatrics. 2010 Jun; 125 (6): e1348-1355.

6. Weaver, J: Single-Sided Deafness: Causes, and Solutions, Take many Forms. Hearing Journal. (2015) 68 (3): p. 22-24.

7. 19.Kerber, S. and B.U. Seeber: Sound localization in noise by normal-hearing listeners and cochlear implant users. Ear Hear. 2012, 33 (4): p. 445-457.

8. 20.Loizou, P.C. Speech processing in vocoder-centric cochlear implants. Adv Otorhinolaryngol. 2006, 64: p. 109-143.

9. Vincent C, Arndt S, Firszt J B, et al. Identification and Evaluation of Cochlear Implant Candidates with Asymmetrical Hearing Loss [J]. Audiol- ogy & Neurotology, 2015, 20 Suppl 1: 87-89