Portland, Ore.

System provides brain images during surgery and information for brain navigation, similar to GPS.

OHSU Hospital is now home to a unique operating room that allows neurosurgeons to track their progress throughout surgery. The surgical suite is equipped with the latest magnetic resonance imaging (MRI) technology, the PoleStar N-10 system manufactured by Odin Medical Technologies. The device is designed for use during neurosurgical procedures, including the removal of brain tumors. At OHSU, the device also assists in the placement of deep brain stimulation devices, used to treat tremors associated with essential tremor and Parkinson's disease. OHSU is the sixth hospital in the U.S. and the first hospital on the West Coast to install this state-of-the-art system.

 

The PoleStar N-10 system can provide images of the brain before, during and after surgery. This allows the surgeon to better plan their approach, evaluate their progress during surgery and verify results.

Prior to the development of intraoperative MRI, neurosurgeons were only able use MRI scans pre- and postoperatively. Using the PoleStar N-10 system, the surgeon can take as many MRI images as needed. The entire process takes a few minutes.

"Intraoperative MRI not only allows the surgeon to be more precise and efficient, the system also helps them make adjustments due to brain shift, the natural movement or 'settling' of the brain, which can take place before and during surgery," said Kim Burchiel, M.D., chairman of the neurological surgery in the OHSU School of Medicine. "Diseased brain tissue and normal tissue look the same to the naked eye. However, tumors are much easier to see using MRI images. By taking multiple MRI images throughout the procedure, we can track and adapt to brain shift. This repeated imaging also helps ensure that we remove all the diseased tissue, preventing the need for repeated surgeries."

Before the first incision is made, a laser beam is used to position the system for surgery. Once correct positioning is determined, the initial MRI images are taken. The machine memorizes its location so additional images during surgery can be recorded from the exact same position. The MRI system is then lowered to its nonactive position under the surgery table to allow full access to the patient. When the surgeon wants to take additional images, the system automatically returns to its memorized imaging position.

Another benefit of the PoleStar N-10 system is intraoperative navigation. The PoleStar's navigation capabilities enable the surgeon to locate clinically relevant structures or sites where anatomical nature is visually ambiguous. The system is similar to a global positioning satellite system in the operating room. The MRI develops an anatomical map for the computer, while an optical camera tracks the patient and special probes for the camera. This same technology has been used at OHSU for years through use of the StealthStation from Medtronic Surgical Navigation Technologies. The major advantage is that this system allows the surgeon to recreate a current 3-D map of the patient intraoperatively as surgery is in progress.

"While intraoperative MRI surgery suites have been constructed in the past at other facilities, they had many limitations," said Johnny Delashaw, M.D., an OHSU neurosurgeon who uses the PoleStar N-10 system frequently. "Those limitations include prohibitively expensive room construction costs, limited access to the patient during surgery, the need for a technician to run the MRI system, and far too many limitations to the kinds of medical instruments that can be used in the room. With this system, none of those problems exist."

The Odin PoleStar N-10 system is distributed exclusively by Medtronic Surgical Navigation Technologies based in Louisville, Colo.