July 12, 2017 - Salem, MA - An overview of Acoustic Neuroma resections and the various surgical approaches.
Acoustic Neuroma, or Vestibular Schwannoma, is a type of benign tumor that affects the vestibulocochlear nerve (Cranial Nerve VIII). As a benign tumor, an Acoustic Neuroma does not metastasize elsewhere in the body. However, though benign, if left untreated, an Acoustic Neuroma can cause hearing loss on one side, tinnitus, and disrupt balance. An Acoustic Neuroma can also potentially affect neurological function and cause death.
It is estimated that in the United States, more than 5,000 cases are diagnosed each year, approximately 7.5% of all brain tumors. One potential treatment option is surgical intervention.
There are currently three surgical approaches for treating an Acoustic Neuroma: the Translabyrinthine approach, Retrosigmoid/Sub-occipital approach, and Middle Fossa approach. Each approach has certain benefits and drawbacks and the correct approach can depend on various factors including the tumor size, location, and determination of whether hearing preservation is possible.
The Translabyrinthine approach is the traditional method and the one with the longest history. The benefits of this approach are that it allows for the maximum tumor resection and easier identification and preservation of the facial nerve (Cranial Nerve VII). However, it is not possible to preserve hearing in the ear and the result is a permanent loss of hearing on that side.
Depending on the size of the tumor and the current status of hearing in the affected side, the Retrosigmoid/Sub-occipital approach might be an appropriate technique. Unlike the Translabyrinthine approach, the Retrosigmoid approach allows for the possibility to preserve hearing. However, while any sized tumor can be removed using this approach, if the tumor is large, it is unlikely that hearing will be able to be preserved in the affected side. An additional benefit of the Retrosigmoid approach is the superior visibility of the tumor in relation to the brainstem. However, one drawback is that it is more common for the patient to experience headaches.
The Middle Fossa approach is ideal for small tumors, particularly if they are situated in the Internal Auditory Canal. This approach also allows for potential hearing preservation in the affected ear.
Each surgical approach has unique benefits and draw backs that need to be considered prior to determining the correct technique. Furthermore, regardless of surgical technique, proper identification of Cranial Nerve VII is necessary. Due to the small operating field and proximity of Cranial Nerve VII to the tumor, the ability to identify, mark, and protect the nerve is important. As the world’s first and only neurosurgical pattie designed specifically for this application, 2 x 20mm Delicot is ideally suited to aid in surgical intervention of an Acoustic Neuroma.
Information courtesy of the Acoustic Neuroma Association. Please visit www.anausa.org for more information.