Cochlear implant- in Medical College & Hospital, kolkata

Prof. Ramanuj Sinha- Head Dept. of ENT

Cochlear implant is a boon for the mankind; surgically placed electrical device that receives sound and transmits the resulting electrical signals to theelectrode array implanted in the scala tympani of the inner ear, thereby stimulating the hair cells allowing patient to hear.As per WHO 15/3/2018 there is an alarming rise in the burden of deafness worldwide. Without appropriate action taken, there will be nearly 1000 million deaf people within 2050.250 million people in the world have disabling hearing impairment (moderate or worse hearing impairment in the better ear)& now in 2018 it is 466 million, of which 34% are children.Nearly 1% of total Indian population are suffering from deafness. Two-thirds of these people live in developing countries.Half of deafness is avoidable and it is the 2nd leading cause of Years Lived with a Disability (YLD). Wayback in 1790 –Alesandro Volta first told that electrical signal in auditory system can create perception of sound.In 1957 first attempt of cochlear implantation was made by Andre Djourno and Charles Eyries with single channel device.First successful cochlear implantation was performed in October 1982,in Melbourne -Australia, when Graham Carrick could hear for the first time in 17 years.In India in1994 the first cochlear surgery was performed in Shimla.Central Government started cochlear implantation under ADIP scheme (Assistance to Disabled persons for Purchasing) in 1995.In our college we are proud to announce that from 2016 till now, we have successfully done cochlear implantation surgery , a total of 15 (10 male,5 female).The most advanced Nuclear 24 machine is now being used. We have now established a proper liaison with National Institute for Hearing Handicapped (NIHH) –Bonhooghly. This has led to running of this program smoothly and successfully. Since 2014 Department of ENT, Medical College and Hospital, Kolkata is providing the facility of OAE (Oto Acoustic Emission) for the high risk newborn referred from paediatric outdoor and well baby clinic. This facility has been revamped this year with state of the art OAE machine (INTERACOUSTICS) from the Govt of WB, which provides more sensitivity to the procedure.This has helped immensely in outdoor screening of deaf and mute children in streamlining the candidature for cochlear implant surgery.

In our college we follow VERIA technique and its recent modification. In this we perform mastoidectomy procedure through the endaural route with incision being made and extended over the scalp for placement of the device.  Cochleostomy with a trans-canal tunnel is drilled into the posterior canal wall.Though the conventional posterior tympanotomy technique has been successful, it is more time consuming. The Veria technique is simple, less time consuming, helps in faster healing,allowsearlier fitting of the processor, and is much precise thereby minimizing trauma to the facial nerve.This technique can also be performed in infants who have not yet developed the mastoid completely.

Very recently we did two cochlear implant surgery in December 2018.We are hopeful that the number of implant surgery will increase day by day with full cooperation from NIHH as well as state governments.The entire ENT department is proud to get such opportunity to do cochlear implant surgery free of cost to the patient.

As told by the great Helen Keller -BLINDNESS SEPARATES US FROM THINGS BUT DEAFNESS SEPARATES US FROM PEOPLE- so by conducting the cochlear implant surgery in our department on a regular basis the burden of hearing impairment, speech and language disability on socio economic spectrum in our state can be significantly dealt with. Also we can convert deaf people to normal hearing people thereby switching them from no hearing world to the world of sound and thereby minimizing the socio-economic burden to the nation.

A                                B

C                               D

A - Devices placed over the temporal bone.

B - Electrode passing through the tunnel.

C- Electrode placement through Cochleostomy.

D- Child with successful Cochlear implant at our institute.