Impact of a self-developed planning and self-constructed navigation system on skull base surgery: 10 years experience.
CONCLUSIONS
Our self-developed planning and navigation system has proven its capacity for accurate surgery on the anterior and lateral skull base. With the incorporation of augmented reality, image-guided surgery will evolve into 'information-guided surgery'.


OBJECTIVE
Microscopic or endoscopic skull base surgery is technically demanding and its outcome has a great impact on a patient's quality of life. The goal of the project was aimed at developing and evaluating enabling navigation surgery tools for simulation, planning, training, education, and performance. This clinically applied technological research was complemented by a series of patients (n=406) who were treated by anterior and lateral skull base procedures between 1997 and 2006.


METHODS
Optical tracking technology was used for positional sensing of instruments. A newly designed dynamic reference base with specific registration techniques using fine needle pointer or ultrasound enables the surgeon to work with a target error of < 1 mm. An automatic registration assessment method, which provides the user with a color-coded fused representation of CT and MR images, indicates to the surgeon the location and extent of registration (in)accuracy. Integration of a small tracker camera mounted directly on the microscope permits an advantageous ergonomic way of working in the operating room. Additionally, guidance information (augmented reality) from multimodal datasets (CT, MRI, angiography) can be overlaid directly onto the surgical microscope view. The virtual simulator as a training tool in endonasal and otological skull base surgery provides an understanding of the anatomy as well as preoperative practice using real patient data.


RESULTS
Using our navigation system, no major complications occurred in spite of the fact that the series included difficult skull base procedures. An improved quality in the surgical outcome was identified compared with our control group without navigation and compared with the literature. The surgical time consumption was reduced and more minimally invasive approaches were possible. According to the participants' questionnaires, the educational effect of the virtual simulator in our residency program received a high ranking.
Caversaccio
Marco
M
Department of ORL, Head and Neck Surgery, Inselspital, University of Bern, Bern, Switzerland. marco.caversaccio@insel.ch
Langlotz
Frank
F
Nolte
Lutz-Peter
LP
Häusler
Rudolf
R
D001918:Brachytherapy / Q000295:instrumentation; D002533:Cerebral Angiography / Q000295:instrumentation; D003198:Computer Simulation; D004427:Ear Diseases / Q000601:surgery*; D001330:Electronic Data Processing / Q000295:instrumentation; D004724:Endoscopy; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D007396:Internship and Residency; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008866:Microsurgery / Q000295:instrumentation; D038361:Neuronavigation / Q000295:instrumentation*; D009668:Nose Diseases / Q000601:surgery*; D010036:Otolaryngology / Q000193:education; D010254:Paranasal Sinus Diseases / Q000601:surgery*; D019047:Phantoms, Imaging; D011183:Postoperative Complications / Q000209:etiology; D012680:Sensitivity and Specificity; D019291:Skull Base / Q000601:surgery*; D012984:Software; D013238:Stereotaxic Techniques / Q000295:instrumentation; D013673:Technology Assessment, Biomedical; D014057:Tomography, X-Ray Computed / Q000295:instrumentation; D014584:User-Computer Interface