Experts map surgical approaches for auditory brainstem implantation

May 21, 2015

A technique called auditory brainstem implantation can restore hearing for patients who can't benefit from cochlear implants. A team of US and Japanese experts has mapped out the surgical anatomy and approaches for auditory brainstem implantation in the June issue of Operative Neurosurgery.

Dr. Albert L. Rhoton, Jr., and colleagues of University of Florida, Gainesville, and Fukuoka University, Japan, performed a series of meticulous dissections to demonstrate and illustrate to auditory brainstem implant placement. Their article shares exquisitely detailed anatomic color photographs, along with step-by-step descriptions of two alternative routes for neurosurgeons performing these demanding implant procedures.

Anatomy and Approaches for Auditory Brainstem Implantation

Auditory brainstem can restore varying degrees of hearing to patients with "retrocochlear" hearing loss. These patients have deafness caused by damage to the cochlear nerves—sometimes called the acoustic or auditory nerves—which transmit sound information from the to the brain. The cochlear nerve damage most commonly results from brain tumors associated with a genetic condition called neurofibromatosis type 2 (NF2).

Auditory brainstem implants are similar in principle to the more commonly placed cochlear implant, used in patients with damage to the cochlea—part of the inner ear. Because of the need to place the implant and electrodes in the brainstem, rather than the inner ear, the surgery required for auditory brainstem implantation is much more complex.

In a series of ten cadaver brainstem dissections, the researchers explored the anatomy of the region that the neurosurgeon must navigate to perform auditory brainstem implantation. They also mapped out the best neurosurgical approaches, both for surgery to remove the tumors and for auditory brainstem implant placement.

Based on their findings, Dr. Rhoton and colleagues detail two surgical approaches: a "translabyrinthine" and a "retrosigmoid" approach. They outline a step-by-step route for both approaches, designed to provide safe access to the area while minimizing trauma to the brainstem and surrounding structures. The authors highlight the value of using endoscopes to help in visualizing and accessing the target area for implant placement.

More than 1,000 auditory brainstem implant procedures have been performed worldwide so far. The procedure was previously approved only for patients with NF2 aged 12 years or older. Recently, clinical trials were approved for children with congenital malformations or other causes of retrocochlear deafness.

Minimizing damage to the brainstem and associated blood vessels appears to be a critical factor in achieving good speech recognition after auditory brainstem implantation. The hearing results are also better in with a shorter duration of deafness.

Dr. Rhoton and colleagues hope that their descriptions and illustrations will help to increase understanding of the anatomy and surgical approaches to auditory brainstem implantation, contributing useful hearing to adults and children with NF2 and other causes of retrocochlear deafness.

Explore further: Researchers explore 3-D microsurgical anatomy of brainstem

More information: "Auditory Brainstem Implantation: Anatomy and Approaches" DOI: 10.1227/NEU.0000000000000736

Related Stories

Researchers explore 3-D microsurgical anatomy of brainstem

December 1, 2014
A study using intricate fiber dissection techniques provides new insights into the deep anatomy of the human brainstem—and helps to define "safe entry zones" for neurosurgeons performing brainstem surgery, according to ...

Researcher observes active role of auditory neurons

April 1, 2015
Cells in the brainstem that underlie sound localization, compare signals at the two ears and can pause while doing so. This was shown by researchers at the Laboratory for Auditory Neurophysiology in Leuven, who were the first ...

Researchers test device to help deaf children detect sounds

February 13, 2015
At age 3, Angelica Lopez is helping to break a sound barrier for deaf children.

Cochlear implantation improved speech perception, cognitive function in older adults

March 12, 2015
Cochlear implantation was associated with improved speech perception and cognitive function in adults 65 years or older with profound hearing loss, according to a report published online by JAMA Otolaryngology-Head & Neck ...

Are expectations more important than sound for auditory processing?

May 18, 2015
What affects how we hear? Do we hear sounds as they are, or do our expectations about what we are going to hear instantaneously shape the way sound is processed? These are questions that Bournemouth University's (BU) Dr Emili ...

Recommended for you

Study shows electric bandages can fight biofilm infection, antimicrobial resistance

November 6, 2017
Researchers at The Ohio State University Wexner Medical Center have shown - for the first time - that special bandages using weak electric fields to disrupt bacterial biofilm infection can prevent infections, combat antibiotic ...

Obesity increases incidence, severity, costs of knee dislocations

November 3, 2017
A new study of more than 19,000 knee dislocation cases in the U.S. between 2000 and 2012 provides a painful indication of how the nation's obesity epidemic is changing the risk, severity and cost of a traumatic injury.

Defining optimal opioid pain medication prescription length following surgery

September 27, 2017
A new study led by researchers at the Center for Surgery and Public Health at Brigham and Women's Hospital analyzed opioid prescription data from the Department of Defense Military Health System Data Repository, identifying ...

Is older blood OK to use in a transfusion?

September 27, 2017
(HealthDay)—Using older red blood cells to give transfusions to critically ill patients doesn't appear to affect their risk of dying, Australian researchers report.

One weight-loss surgery shows lasting results

September 21, 2017
(HealthDay)—Obesity surgery can have long-lasting effects on weight and the risk of developing type 2 diabetes and high blood pressure, a new study finds.

Hold the phone: An ambulance might lower your chances of surviving some injuries

September 20, 2017
Victims of gunshots and stabbings are significantly less likely to die if they're taken to the trauma center by a private vehicle than ground emergency medical services (EMS), according to results of a new analysis.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.