'Keyhole' procedure safer than invasive approaches in removing acoustic neuroma without hearing loss

Oct 14 2010

Results from a newly released 9-year study is bringing newfound hope to the approximately 3,000 Americans diagnosed each year with acoustic neuromas (AN), little-known brain tumors that can have devastating and even fatal consequences for sufferers. The study of 527 patients conducted and championed by renowned brain surgeon Hrayr Shahinian, M.D., medical director of the Skull Base Institute in Los Angeles, shows that his minimally invasive "keyhole" procedure is safer and more effective than the invasive approaches favored by most surgeons. Patients undergoing the keyhole technique were more likely to have their hearing preserved, experience far less facial paralysis and enjoy fewer post-operative complications than those undergoing traditional procedures.

“It's also well tolerated by patients with minimal discomfort and recovery times are faster.”

The study, which was completed in July 2010 and will be published in the next issue of the peer-reviewed journal, Minimally Invasive Neurosurgery (MIN), will show the following:

• An astounding 94% of AN tumors were completely removed and 6% mostly removed using the keyhole procedure.
• 100% of patients experienced preservation of their facial nerve (facial paralysis is a common complication with the traditional invasive surgery)
• Hearing was preserved in 57% of keyhole patients while those undergoing more traditional invasive approaches fared less favorably (i.e., one such procedure, the translabyrinthine approach, results in total hearing loss in 100% of patients)
• No significant neurological complications occurred in any of the keyhole cases compared with up to 20% through traditional surgical options

The keyhole technique involves making a dime-sized opening behind the ear and using custom-designed micro-instruments to remove the tumor. No metal retractors are used to push the brain aside during this procedure thus reducing chances of brain damage.

The traditional technique, on the other hand, requires a team of surgeons who begin the procedure by making a four- to five-inch C-shaped incision behind the patient's ear. Since ANs are situated on the eighth cranial nerve near the hearing canal, open procedures oftentimes cause patients to lose their hearing as surgeons attempt to remove the tumor. AN's proximity to the seventh cranial nerve also leaves patients vulnerable to permanent facial paralysis, making it impossible to smile, close one's eyes or activate any movement on the affected side of the face.

AN symptoms include:

• Hearing loss
• Persistent or intermittent ringing in the ears
• Vertigo
• Dizziness
• Headaches

"We have found that the fully endoscopic (keyhole) approach is far safer than traditional surgery and offers patients the best chance at removing the acoustic neuroma without resulting in hearing loss or suffering facial paralysis," said Shahinian. "It's also well tolerated by patients with minimal discomfort and recovery times are faster."

SOURCE Skull Base Institute