Here Are Some New Advances in Sinus Navigation Systems

by Nikki Kean •

You have the benefit of dual information: The CT scan tells you the areas of bony erosion, for example, and the MRI tells you the extent of the tumor. The surgeon can toggle back and forth between the two images as they are navigating.

—Jivianne Lee, MD

A second advance involves navigation software that facilitates simultaneous navigation using multiple imaging modalities. “We now have the ability to merge CT and MRI [magnetic resonance imaging] together,” Dr. Lee said. “Traditionally, we would navigate off the CT scan for our endoscopic sinus surgery cases.” Now, she explained, with innovations in surgical navigation software, the CT and MRI can be used concurrently during intraoperative tracking, which can be particularly useful during endoscopic resection of sinonasal and skull base tumors. (Dr. Lee is a consultant for Medtronic ENT and Stryker ENT.) 

Advances in Visualization 

The manufacturers of the navigation systems have taken two approaches to improved visualization: augmented reality and virtual reality. 

Augmented Reality. “Augmented reality [AR] is when you take annotations that the surgeon makes on the preoperative imaging [usually the CT scan] and overlay those annotations on the endoscopic camera view,” said Dr. Citardi. 

In a study of AR systems, researchers compared conventional navigation software (n = 52) with a navigation software incorporating AR elements (n = 48). To evaluate the benefit provided by both navigation systems, the surgeons had to complete a questionnaire after finishing the operation. Surgeons reported a higher benefit when they spent a longer time with preoperative image analysis when using the AR system and used the navigation system for more surgical steps as compared with the conventional system. The authors concluded that “the AR-enhanced navigation software offers potential benefits during surgery without affecting the duration of the operation or the incidence of postoperative complications” (Larnygoscope Investig Otolaryngol. 2020;5:621-629). 

“AR technology permits virtual elements to be overlaid on the endoscopic surgical view in real time,” said Waleed M. Abuzeid, MD, an associate professor in the department of otolaryngology–head and neck surgery and a specialist in rhinology and skull base surgery at the University of Washington in Seattle. “Take the example of a surgery for a complex skull base tumor. The surgeon can use the surgical navigation system to outline critical structures, including the tumor target, as well as anatomy that one wishes to avoid, such as critical nerves and vascular structures,” Dr. Abuzeid said. (Dr. Abuzeid is a consultant for Medtronic.)