“By performing surgery through the eye socket, we eliminate the need for a full craniotomy, gain equivalent or better access to the front of the brain, and eliminate the large ear-to-ear scar associated with major brain surgery,” says Chris Bergeron, MD, assistant professor of surgery in the head and neck division at UC San Diego Health System. Bergeron says that the technique also protects neurovascular structures such as the optic and olfactory nerves.
Patients underwent the TONES procedure to repair cerebral spinal fluid leaks, optic nerve decompression, repair of cranial base fractures, and removal of tumors. Given further research, the surgeons believe that TONES may serve as a means to treat pituitary tumors, meningiomas, and vascular malformations. TONES is currently performed at only two institutions: UC San Diego Medical Center and the University of Washington Medical Center.
In a traditional craniotomy, a large portion of skull bone is removed. With TONES, the area of bone removed is only two to three centimeters. The operating time is much shorter since the skull does not need to be repaired and there is no need to close a large incision.
To achieve access, the surgeons make a small incision behind or through the eyelid. A tiny hole is then made through the thin bone of the eye socket to reach the brain. This pathway allows repairs to be made without lifting the brain. The TONES approaches protect the optic and olfactory nerves, as well as the carotid and ophthalmic arteries. The study participants have observed reduced pain and a quicker recovery time.
Transnasal surgery, a technique performed through the nose, offers similar access to some areas of the brain but means a more crowded operating environment for the surgeon than TONES. Kris Moe, MD, chief of the division of facial plastic and reconstructive surgery and professor of otolaryngology at the University of Washington Medical Center, pioneered the TONES method in 2005. He says the technique builds on the nasal approach, which usually requires four sets of hands, but offers increased maneuverability and visibility for the surgical teams.
Researchers included Kris Moe, MD, Chris Bergeron, MD, and Richard Ellenbogen, MD. The findings were published in the September issue of Neurosurgery.