| MCV ENT UPDATE | ||||||
| Update : January - March 2007 | ||||||
| REFINEMENTS IN COCHLEAR IMPLANT - Cuts cost |
||||||
| • Nucleus 24 channel treatment package 5.5 lakhs • Early switch on - 7 days cf. 21 days • Implant placed away from incision • Smaller incision with less morbidity |
||||||
A cochlear implant is a hearing prosthesis designed to restore or provide a level of auditory sensation to adults and children who have a severe to profound bilateral sensori-neural hearing impairment and who get limited or no benefit from hearing aids. |
||||||
|
||||||
 Cochlear implant consists of a body worn or behind the ear speech processor, a receiver stimulator which receives and decodes the electrical signal and an electrode array which delivers the signal to the cochlea.1. Selection criteria: Children and adults with bilateral profound sensori-neural hearing loss. Individuals with PTA > 70dB and speech discrimination less than 20-30% are accepted. 2. The age of implantation has slowly been lowered from 2 years through 18 months to one year. Younger the age of implant, better is the outcome and Ideally a congenital pre--lingual deaf child should be implanted by 2 years of age. A variety of incisions have been used in the past. Cochlear implants were always performed using the same type of C shaped incision as used for routine mastoid surgery. However it was significantly enlarged so that the incision line did not overlap the implanted stimulator. In the mid 1990s an inverted U shaped incision became very popular. The rationale behind the use of this incision was that, all the blood flows from inferiorly upwards in the post auricular region thus decreasing the chances of a vascular necrosis of the flap. |
||||||
 |
||||||
In recent times the lazy ’S’ or inverted ’J’ incision have become quite common. This extensive exposure made the technique easier for developing the bone well for the implant receiver. The disadvantage seen with this kind of incisions were increased incidence of wound breakdown, infection and a prolonged hospital stay. |
||||||
 |
||||||
We at MCV employ the use of a small 5cm curvilinear incision extending from just above the superior attachment of the pinna to the upper posterior point of mastoid process. This incision in our experience of 26 implants gives adequate exposure without extensive tissue retraction. The bone well for the implant is made under the skin flap by elevating small but adequate periosteal pocket. The implant is fixed flush to skull with Teflon tapes so that no external swelling is visible. The main Advantage of this technique are a definite decrease in operating time, (1½ to 2 hrs) there by minimizing the exposure of the device and hence less risk of post op infection and reduced morbidity. Less shaving of the operative site reduces infection due to Staph aureus. This technique also cut down the patient’s hospital stay from 10 days to about 4-5 days. Early removal of sutures enables an early “switch-on” of the device. In our case we switch-on the device on the 7th day as compared to the conventional regimen of 3 to 4 weeks post op. |
||||||
 |
||||||
 |
||||||
 |
