Cochlear implant surgeries

Deaf people, for one reason or another, face daily challenges that people with hearing cannot even comprehend. With time, medicine managed to develop several solutions to make life easier for the hearing impaired and allow them to hear better. One of the most advanced and wondrous means in this regard is the cochlear implant surgery.

The cochlear implant surgery is meant to address deafness or severe hearing impairment related to the activity of the cochlea – one of the organs in the auditory system, that sends electrical signals via the tiny hairs in it to the hearing nerve, and from there to the brain. The cochlea is one of the most important organs in the hearing process, and that’s why when it’s damaged or dysfunctional, the hearing ability will be significantly harmed.

Cochlear implant surgeries are meant, in fact, to provide an alternative to the so important cochlea During them, a “new cochlea” is implanted, which is actually made of a few electronic units. Their goal is to simulate the action of the original cochlea and in other words – to create electrical signals that the hearing nerve can transmit to the brain, to be interpreted and processed into sounds.

General information about the cochlear implant surgeries

The cochlear implant surgeries are considered pretty complicated and last about 3-4 hours. The entire system is made of external and internal parts that together allow creating the electrical signals that are transmitted to the hearing nerve.

In the external part of the head, around and a visible unit that has a microphone, sound processor and magnet are affixed to the skull bone. On the other side, under the skin, a receiver is affixed, which also has a magnet in order to create the link between it and the external unit. That receiver can not only receive the sounds but also process them and to transmit them through a thin wire to electrodes that are placed in the cochlea. Those electrodes create the electrical signals that are transmitted to the hearing nerve and from there to the brain.

It’s important to note that the surgery isn’t right for every person, and doesn’t solve all hearing problems that may be. For example, if a person has been suffering from severe hearing impairment for years or is in advanced age and has been defined as deaf for many years, the chance that the surgery will help him is slim, since he is no longer in a position to learn and acquire a language properly.

For this reason, the cochlear implant surgeries are appropriate for mostly 2 cases:

• When the patients are babies or small children (the best recommended period for the surgery is up to the age of 1, but the surgery has been found to be effective around the age of 5 as well, and sometimes even older)
• When a patient is a person whose severe hearing impairment occurred relatively late after he acquired a language.

We’ll note that the cochlear implant in one ear doesn’t contradict using a hearing aid in the other ear, and vice versa: many patients have reported that they heard better in the ear with the hearing aid as well, after the cochlear implantation in the other ear.

Preparation for the cochlear implant surgery

The surgery cannot be performed where there’s an ear infection, so prior to the surgery, a test will be carried out to rule out an infection, if there’s a concern for one. In certain cases, other preliminary tests would be performed prior to the surgery, like a general ear test, blood tests and more.

Since the surgery is performed under general anesthesia, a fasting of several hours would be required before it.

Course of action

The cochlear implant surgeries are performed, as mentioned, under general anesthesia. After the anesthesia, the action would begin, during which a tiny opening will be made in the skull, in the bone behind the ear. Through this opening, the electrode will be inserted into the cochlea in the inner ear. Under the skin, the receiver will be affixed, connected to the electrode via thin wire, and on the other side, in the outside part, the microphone will be affixed.

The action takes time, as said, but it’s been performed for many years and is considered today as having very high rates of success. Candidate eligible for the cochlear implant surgeries are reporting significant hearing improvement shortly after, and those who never heard before – are beginning to hear, which many would define as a true wonder.

Despite all of this, you should remember that this is not an automatic improvement: although the patient will begin to hear sounds around him, only through the right treatments and proper professional escort he would be able to adjust to hearing in this way and to develop a language, if he hasn’t done so (relevant for very young ages). Therefore the success of the surgery also depends on the “work” done after it. We’ll further note that patients have the disease for several weeks until the system, which was planted in the patient’s head, is ready for action – only then will the actual hearing phase begin.

Possible adverse events

Aside from the adverse events that sometimes occur after general anesthesia (nausea, vomiting and so on), the surgery might cause relatively late adverse events – meaning, those not caused immediately after the surgery – like movement of the implant or disruption of one of its parts, damage to the rehabilitated hearing along the years and meningitis. The spot through which the electrode is inserted into the cochlea is next to the facial nerve, and there’s a risk for damaging it.

Despite all those, it’s important to remember that the skills of the medical staff and the experience gathered along the years reduce the risks for these cases to a minimum.