Called a lateral paramedian transpedicular approach, the technique uses advances in spinal instrumentation and reconstructive strategies to provide a direct approach to the removal of cervical spinal tumors with minimal, or no, neural manipulation.
The procedure is reported in the November issue of Operative Neurosurgery. UCSF is the only medical institution in the United States where patients can undergo this surgery.
Developed by neurosurgeon Christopher Ames, MD, co-director of neurospinal disorders and director of the Spinal Biomechanics and Spinal Neuronavigation Laboratory at UCSF Medical Center, the surgery uses standard and innovative devices to first remove and then reconstruct portions of the cervical spine in order to access tumors. Once the bone is removed, surgeons have a direct line of sight to the tumor and are able to remove it in its entirety without having to move or manipulate the spinal cord.
After the tumor is removed, surgeons immediately rebuild the spine with artificial pedicle screws, a reconstruction technique also developed by Ames. The technique is particularly useful in cases in which the tumor is located in the middle of the spinal canal and attached to the lining of the spine. These types of tumors include meningiomas, neurofibromas and exophytic astrocytomas.
Patient Stacey Hall recently underwent surgery to remove a neurofibroma, a usually benign tumor of the peripheral nerves. Hall's tumor caused her skin to be acutely sensitive to touch, her hands to experience numbness, and her legs to collapse from under her at times. "The damage was so severe, the slightest breeze against my skin caused me excruciating pain," said Hall. "The first thing I noticed after my surgery was that my skin no longer hurt for the first time in more than a year."
Most of the surgeries to date have been done on patients with conditions similar to Hall. Neurofibromas can occur as a sporadic condition or as a genetic disorder such as neurofibromatosis. While a common type of spinal tumor, neurofibromas are challenging lesions to approach surgically, according to Ames. Found at the base of the skull on or near the spine, the tumors often sit just below the brain stem and press against the spinal cord as they grow.
Some tumors span several vertebral levels. In time, the pressure against the spinal cord can cause pain, numbness and loss of mobility in the hands, arms and legs. If left untreated, patients can become paralyzed. Because of the proximity to sensitive anatomy including the spinal cord, pharynx, nerves, and major blood vessels, surgeons often refuse to operate for fear of causing irreversible nerve damage, paralysis and even death, Ames noted, and as a result, patients presenting with extensive intradural tumors are often left without hope.
"We are treating patients with this technique who were told by physicians that nothing more could be done," said Ames. "The next step is to train other surgeons in the technique so it is accessible to patients throughout the country."
Ames specializes in spinal reconstructive surgery for trauma, tumors and degenerative disease. His research focuses on new techniques for computer-guided, minimally invasive instrumentation and development of resorbable materials for spine stabilization and growth factor delivery. He is the first surgeon in California to do a percutaneous pre-sacral fusion, of which there have been less than 15 in the country. Ames completed a complex spine fellowship at the Barrow Neurological Institute in Phoenix, Arizona.
UCSF is a leading university that consistently defines health care worldwide by conducting advanced biomedical research, educating graduate students in the life sciences, and providing complex patient care.
PATIENT INTERVIEWS: Arrangements can be made to interview patients who have undergone this surgery and to view the surgery. Original sketches and photographic images of the procedure are also available.
CONTACT: For more information, or to interview Christopher Ames, MD, contact Vanessa deGier at (415) 476-2557.