Amin Kassam

The device is extremely valuable during delicate microvascular decompression surgery for hemifacial spasms (HFS), according to Amin Kassam, M.D., assistant professor of neurological surgery and director of the Center for Cranial Nerve Disorders and Microvascular Surgery. HFS is an involuntary twitching of one side of the face. It usually starts around the eye and slowly progresses to involve the lower face. The muscles in the forehead and neck are usually the last to be affected. Although rarely painful, there is no medical treatment that can cure HFS, which is caused when a facial nerve in the lower brainstem is compressed by blood vessels.

In microvascular decompression surgery, surgeons make a small incision behind the patient’s ear to access the appropriate blood vessels and nerves. They then insert a soft cotton-like pad between the affected nerve and the offending arteries or veins to separate the two and relieve pressure.

“This device gives us a better visualization of critical brain structures. It allows us to see behind anatomical structures, thus minimizing the risk of injury and maximizing identification of hidden blood vessels that might be causing the HFS,” said Kassam. “We are better able to optimize our manipulation of instruments within this small surgical field (about the size of a thumbnail) without injuring adjacent critical structures. This (device) has allowed us to achieve a greater than 95 percent chance of controlling the HFS.”

The technique is similar to television’s picture within a picture. The simultaneous use of a surgical microscope with that of a surgical endoscope (a tiny slender camera used in minimally invasive surgery that uses light and mirrors) optimizes safety while further improving results.

“Using this device can be compared to driving a car,” said Michael Horowitz, M.D., associate professor of neurosurgery and radiology, who, with Kassam, operates on patients with HFS, trigeminal neuralgia, and glossopharyngeal neuralgia. “A driver can see different angles with the side and rear-view mirrors. If the driver has to turn his head and look behind him, he is more at risk for crashing. With the car’s mirrors, the driver can focus on what is ahead, but get a different view.”

—Frank Raczkiewicz