The development of medicine, especially in the field of Ear Nose, Throat, Head Neck Surgery (ENT-KL), has grown rapidly. Problems in hearing can be overcome with updated science every time. Congenital sensorineural hearing loss (SNHL) is the most common problem. This occurs due to damage to the inner organ of the ear (cochlea), which results in the inability to conduct sound vibrations through the ear fluid.

As a result, hearing function is reduced, so the patient cannot hear properly. The treatment for this hearing problem is a cochlear implant. This hearing aid is inserted in the ear’s inner organ to reactivate the ear’s natural function to respond to incoming sound vibrations. However, cochlear implants often traumatize the patient. The surgery performed can potentially cause discomfort or even cause malfunction of the cochlear implant itself.

Every human being has a different cochlear size, so medical personnel need complete knowledge of the patient’s ear space dimensions, including the ear cavity’s width, height, and length. Research on cochlear size variation in cochlear implants is essential to understanding its effect on clinical outcomes and developing better implant technology.

ENT-KL experts Devira Zahara, Rima Diana Dewi, and Askaroellah Aboet; Radiologist Fikri Mirza Putranto; and Environmental Health Expert Taufik Ashar from the Universitas Sumatera Utara, Indonesia, studied the cochlear size of cochlear implant patient candidates in Medan, Indonesia. The study aims to present data on patients’ cochlear size (height, width, and length) that can be used as a reference for medical personnel to perform cochlear implants.

“The study started with analyzing cochlear size variation in different patient populations. There is significant variation in cochlear size between individuals, which may affect the effectiveness of cochlear implants. Precise and objective measurement of cochlear size will affect the acquisition of normative data of cochlear size including length, width, height, tympanic scale height (ST), and cochlear canal length (CDL),” said Devira Zahara.

Measurements are made by collecting data on the temple bone using high-resolution computed tomography (HRCT), which is then used as material for three-dimensional (3D) reconstruction. Eighteen cochlear implant candidates, or 36 ears, were used as measurement objects. The measurement results show variations in size from individual to individual.

Imaging technology provides a detailed picture of the cochlear structure, allowing medical personnel to measure the cochlea accurately before surgery. The implant prepared can also be customized for each patient. A smaller cochlea may cause difficulty in electrode placement, and as a result, electrodes placed in the cochlea may not provide optimal stimulation.

Optimal stimulation. “Variations in cochlear size can affect electrode placement and hearing outcomes. Accurate knowledge of cochlear anatomical variations is essential to maximize clinical success,” says Devira Zahara.

On the one hand, shallow cochlear electrode insertion might reduce the risk of apical structural damage. However, deep cochlear electrode insertion is needed to improve implant performance in hearing loss cases. This demonstrates the importance of proper cochlear measurements for inserting electrodes for good implant performance.

The research also gathered data from previous studies to support the team’s findings. The data was used to reference that cochlear anatomy variations can affect hearing outcomes. On the other hand, an individualized approach to cochlear implant placement is equally important, including better diagnostic tools to measure the cochlea before surgery.

“An individualized approach based on the patient’s cochlear size can significantly improve clinical outcomes. Including the availability of more accurate diagnostic tools is necessary for better surgical planning,” said Devira Zahara.

Of course, cochlear implants present challenges for cochleas of unusual size. So, the research team recommends developing better clinical guidelines to help doctors deal with cochlear size variations. Clinical guidance and a better understanding of cochlear size variation could improve patient hearing outcomes.

They concluded that using the right electrode can produce good hearing after cochlear implantation. Data on cochlear canal size can provide information to aid the design of individualized cochlear electrode insertion. They recommend further research that is adapted to the times. “Further research is needed to develop implants that can adapt to each individual’s cochlea size,” concluded Devira Zahara.