Intraoperative navigation in surgery of paranasal sinus and anterior skull base

Background and objective. Based on physical laws, stage of technical development and the user's individual skills a number of possible errors have to be considered for the application of CAS in paranasal sinus and anterior skull base surgery. Patients/methods. Based on our experiences of 436 navigated cases hard- and software errors, errors of image acquisition and transfer, errors of patient registration, user related errors as well as strategic errors are analyzed. Results. Any hindrance of the camera field leads to a limitation of functionality of optical systems in the same extent as electromagnetic systems can be affected by ferromagnetic materials. The mode of image acquisition is dependent from the CAS-system involved. The reconstruction algorithm requires particular attention. The patient registration based on the headset proved to be reliable for endonasal sinus surgery. Conclusions. In dealing with navigation devices in paranasal and anterior skull base surgery the user must pay critical attention to possible malfunction in order to guarantee a successful image guided surgical procedure.