At the turn of the 1900s, treatment for acoustic neuroma was primarily surgical and often complicated. Surgery was complicated by the lack of advanced imaging that today allows for early detection. Although surgical treatment was life-saving, it provided little opportunity to preserve facial function or hearing in patients.
High-resolution magnetic resonance imaging (MRI), microsurgical technologies and the creation of dedicated treatment teams have made facial nerve preservation the norm in treating acoustic neuromas. With further advancements in technology, experts are able to identify smaller tumors, leading to hearing preservation – the next frontier in the management of acoustic neuromas.
Hearing preservation is possible when tumors are up to about two centimeters in size. The best way to preserve hearing in the immediate and intermediate (up to five years) periods is to follow a “wait-and-see” strategy. Depending on the acoustic neuroma, this strategy can preserve hearing for up to 10 years. Although this approach is reasonable for some small intracanalicular tumors, most published studies show that progressive hearing loss occurs in 50 to 70 percent of patients over the first four to five years, even when there is no tumor growth.
The USC Acoustic Neuroma Center at Keck Medicine of USC in Los Angeles is equipped with state-of-the-art imaging (CT and MRI), GammaKnife® and a world-renowned team of surgeons. We often are able to identify the nerve where smaller tumors have originated, allowing for precise treatment planning.
At the center, we continue to refine our treatment strategies to support hearing without compromising tumor control. We are leaders in the use of hearing preservation procedures such as retrosigmoid and middle fossa surgery.
The retrosigmoid approach is useful for tumors up to 2.5 centimeters in size that are positioned nearer to the opening of the internal auditory canal. Preoperative functional testing, which includes testing for hearing and balance and the use of MRI, determines candidacy for this approach.
The middle cranial fossa approach is best used for tumors that are up to 1.5 centimeters in size and extend toward the end of the internal auditory canal. Hearing preservation through the middle fossa can be achieved in up to 80 percent of cases. In experienced hands, this approach allows for early and safe identification of the facial nerve by providing a complete view of the internal auditory canal and its contents, thereby enabling safe tumor removal. This procedure is relatively brief, lasting about three to five hours and is safe in the hands of experienced skull base surgeons.
For more information, contact the USC Acoustic Neuroma Center for a consultation by calling (800) USC-CARE (800-872-2273).