Acoustic neuromas are benign tumors that cause hearing loss, tinnitus, and dizziness. They are one of the most common brain tumors diagnosed in the United States, which translates to about 3,000 new cases each year. Several treatments are available for these tumors, depending on the size of the tumor, symptoms, patient age and overall health.
For more than 20 years, George Wanna, MD, Executive Vice Chair of Otolaryngology – Head and Neck Surgery and Chief of the Division of Otology-Neurotology at the Mount Sinai Health System, has specialized in the surgical management of acoustic neuromas. He has performed approximately 1,000 procedures to treat these unusual tumors and improve the quality of life of his patients.
Acoustic neuromas can be treated surgically in a variety of ways. As a pioneer in the field, Dr. Wanna specializes in several approaches, including removal of the tumor endoscopically through the ear canal. Dr. Wanna was one of the first skull base surgeons to use the exoscope, or a robotically controlled microscope. The exoscope offers surgeons increased visualization with high-definition, real-time imagery.
George Wanna, MD
In this Q&A, Dr. Wanna explains the various treatment options for acoustic neuromas, and he answers common questions about the benefits of endoscopic surgery, the use of radiation, and how the exoscope can improve outcomes for patients.
How is acoustic neuroma removed endoscopically? How is this surgery different from conventional, “open” surgery?
An endoscopic approach allows us to access the tumor through the ear canal without any major incisions. The endoscope is a thin, rigid tool with a light and high-definition camera attached to the end. We use it to look through the ear canal, behind the ear drum and inner ear, and into the brain. It can be our main surgical tool or used in combination with open surgical techniques that require an incision. Often the endoscope will allow for a more minimally invasive approach, even when used as an adjunct in open surgery.
What are the benefits of using an endoscopic approach?
There are no major incisions. The procedure is done entirely through the ear canal. Patients who have endoscopic surgery recover faster and typically go home within 48 hours.
Who is a candidate for endoscopic surgery?
Every case is different, and it is important to individualize the approach to each patient with the goal being to treat the tumor in the safest, most effective way. Patients with small tumors who have lost their hearing are ideal candidates for endoscopic techniques. Conventional, open surgical approaches are used to treat larger tumors in deeper locations. In some cases, a wait-and-see approach is taken for patients with smaller tumors and good hearing, or those with stable tumors. Typically, we do not operate on small, stable tumors (less than 1 cm). However, if the tumor is growing and the patient prefers it to be removed, we may perform surgery earlier than expected.
How do you know the size of the tumor?
We assess tumor growth using MRI scans. We measure the tumor in 3 dimensions and compare each dimension and overall volume from scan to scan. These measurements are then used to help guide decision making along with the patient.
Does endoscopic surgery reduce potential side effects like facial paralysis or cerebrospinal fluid (CSF) leak?
At Mount Sinai, our acoustic neuroma surgeons have extremely high success rates with endoscopic surgery and were one of the first adopters of the technology in ear surgery. As one of the highest volume endoscopic ear surgery centers in the world, we have adapted our experience to acoustic neuroma surgery. For example, we have found that packing the Eustachian tube under direct visualization reduces the risk of CSF leaks. In essence, we employ the principles of conventional, safe surgery and use the endoscope to accomplish the same goals in a minimally invasive approach.
Is radiation used after surgery? Does everyone need it?
This is a vibrant discussion in the field of otology-neurotology. Radiation is used in certain patients, If the tumor is large and pressing on the brainstem, surgery is most appropriate. Radiation should only be used when there is MRI documentation of tumor growth and can be the treatment of choice for elderly patients or those with other existing comorbidities. In some cases, the acoustic neuroma cannot be completely removed without causing facial paralysis; in those cases, a very small remnant is purposefully left behind, and if it grows, is radiated.
What is the exoscope? How does it help surgeons visualize the tumor?
The exoscope is a specialized microscope with a robotic arm. It can generate 2D or 3D images and is guided by voice command. It has a built-in surgical GPS which allows us to see in real time on a CT scan or MRI exactly where we are. This exceptional visualization of the patient’s anatomical structures is unprecedented.
What are the benefits of coming to the Ear Institute of New York Eye and Ear Infirmary of Mount Sinai?
While acoustic neuromas are relatively uncommon, we are one of the highest volume centers in the country, giving patients the advantage of seeing providers who have treated the full spectrum of these tumors, including the most complex cases. We work very closely with our colleagues in neurosurgery and radiation oncology to ensure patients receive the most appropriate and optimal treatment for them. Our extensive support staff guides patients through every step of the way.
What are the benefit of collaboration between surgeons and trainees at the Ear Institute?
The exoscope projects a real-time, high quality display of anatomical images that both neurosurgeons and otologists can view simultaneously, rather than individually through a microscope. This creates a true collaborative approach between surgeons and anesthesiologists, as well as for other medical experts (domestic and international), who may be observing the procedure. This technology has also greatly enhanced the educational experience at the Icahn School of Medicine at Mount Sinai for residents, fellows and medical students, as we continuously harness innovative technology for the next generation of surgeons.
To make an appointment with Dr. Wanna at the Ear Institute of New York Eye and Ear Infirmary of Mount Sinai, please call 212-979-4200 or email NYEEentreps@mountsinai.org.