A COMPARISON OF IMAGE GUIDANCE SYSTEMS FOR SINUS SURGERY

Objective: Intraoperative computed tomographic guidance systems are av ailable which utilize either electromagnetic (radiofrequency) or optic al (infrared) signals to localize instruments within the surgical fiel d. The objective of this study was to compare the use of these two dif ferent image guidance technologies for sinus surgery. Study Design: Pr ospective cohort study. Methods: The electromagnetic-based InstaTrak s ystem (n = 24) and the optical-based Stealth-Station (n = 49) were com pared in a series of 73 consecutive sinus series which utilized image guidance technology, Results: Both the electromagnetic and optical sys tems provided anatomic localization to within 2 mm during surgery. Int raoperative reregistration was effective in correcting for any anatomi c drift. There were no intraoperative complications. Mean operative ti mes were 156.3 +/- 8.9 minutes for the electromagnetic and 139.2 +/- 1 7.7 minutes for the optical system (P < .05), The average intraoperati ve blood loss did not differ significantly between groups (electromagn etic, 190.6 +/- 28.7 mL; optical, 172.4 +/- 23.0 mL). Each system was noted to have limitations. The presence of metallic objects in the ope rative field interfered with functioning of the electromagnetic system , whereas the optical system required a clear line of sight to be main tained between the infrared camera and surgical handpiece. Both system s required specialized headsets to be worn by patients during surgery to monitor head position. The electromagnetic system also required the se headsets to be worn during the preoperative computed tomography sca n. Conclusion: Although these two image guidance systems both proved v aluable for anatomic localization during sinus surgery, individual pre ferences can be based on distinct differences in their design and oper ation.