Did You Know…

…that Navigation Systems Can Be Used For Brain Surgery?

GPS (Global Positioning System) is the epitome of modern, satellite-based navigation. Originally developed for military purposes, navigation – guidance based on constant positioning and accurate map information – is now a key field in many civilian areas as well. In cars, navigation systems are practically standard nowadays. Surgical navigation solutions have been around since the 1990s and are being employed in various disciplines, such as brain surgery, where they make procedures gentler and safer, thereby minimizing damage to healthy tissue.

A certain amount of preparation is necessary, however. With the aid of imaging systems such as CT/MRT, a kind of 3D digital map of the patient’s brain and of the diseased area (e.g. a tumor or vascular anomaly) can be generated prior to the planned surgical procedure. Based on this 3D patient information, the neurosurgeon then draws up a plan for the operation on the navigation computer, marking important anatomical structures such as the tumor or certain areas of the brain that have to be avoided and pinpointing entry and target points in the brain for surgery. This information is then fed into the navigation system.

During the operation, various markers on the patient and on defined navigated surgical instruments are used for orientation purposes. The positions of the navigated instrument, e.g. an aspirator or a probe, and of the patient are measured and displayed on the monitor using an infrared camera system. This provides the surgeon with important supplementary information about the current position of the instruments and the tumor, their distance from each other, tumor size, etc. While the surgeon is pressing forward to the tumor, the navigation system indicates where care needs to be taken so as not to damage certain structures that are in the way.

Modern surgical microscopes like the ZEISS OPMI PENTERO 900 are already equipped for neurosurgical navigation applications and can be linked to navigation systems like these. A small monitor in the microscope – the data injection system – enables doctors to see the navigation data directly in their field of vision without having to turn away from the microscope to glance at the navigation system monitor.

But, just as with driving, these navigation solutions are not 100 percent perfect, so it is still vital for the surgeon to monitor the procedure And constantly keep a critical eye on the navigation information displayed for the tumor to ensure that it is correct. For this reason, the surgeon is regularly asked during the surgery to verify the accuracy of the current navigational data. In the event of an error, the navigation system can be turned off at any time during the operation. Navigation systems make valuable contributions and help ensure successful procedures, but they cannot replace a surgeon’s years of experience or make up for deficient anatomical knowledge.

21 September 2011