New Technology in Image-Guided Sinus Surgery
There have been various advances in technology, instrumentation and adjunctive aids in image-guided sinus surgery. In this presentation, the most pertinent advances, which have patient applications, will be discussed in detail.
Computer Aided Surgery
The recent introduction of computer aided technology in the field of image-guided sinus surgery has enhanced the surgical approaches to the areas of sinuses which in the past carried a high risk. This technology may be electromagnetically or optically guided by light emitting diodes. The electromagnetic system is currently popular and there are various applications which are reliable in performing secure endoscopic sinus surgery. These systems are based on the sensitivity of calibration and the accuracy of the target surgical site as based on the maintenance of calibration.
The electromagnetic system (VTI Corporation™) is based on a transmitter/receiver system. The patients usually undergo a CT scan prior to surgery with a special headset; this information is stored on a disc where reconstructions in the coronal and sagittal plane are carried out. The newer systems have the option of 3D reconstructions with cut-outs and this aids in the localization of the surgical site accurately. This progress in imaging development has changed certain surgical applications in a dramatic manner. The probes inserted at the surgical site are available in different shapes and adaptation to power instrumentation has made surgical applications versatile. The position of the probe is confirmed on a calibration platform and the surgical site is plotted on an X-Y axis.
The optical systems are based on a line of sight light-emitting diodes which are captured in a 3D camera and processed by a computer in a triplanar view similar to the electromagnetic system. These are currently an active and passive infrared systems that are available for surgical applications. They also use a transmitter from the probes or instruments.
The computer aided systems are useful when the anatomy inside the nasal cavity or the sinuses is distorted, either from the disease process or prior surgery. They are useful in planning anterior skull base surgical resection in selected cogenital defects and tumors. The system provides an excellent tool in identifying the site and location of the tumor, their size and a prediction of the surgical defect after resection. Since this is not a real time application of the radiologic finding, one has to plan the resection and reconstruction simultaneously. Pre operative surgical planning may be useful in determining the requirements of the surgical site.
Here are some Triplanar views (click for larger picture):