The State of the Art of Image-Guided Surgery

Where the standard of care can fall down is if the surgeon doesn’t perform the appropriate diagnostic workup-such as not doing a sinus CT prior to sinus surgery-or if there is inappropriate medical treatment or a failure to discuss the risks, benefits, and alternative to surgery with the patient.

IGS can help you identify and confirm landmarks that you should be aware of. But you have to know what to do when you get there, Dr. Parikh said. Also, use of IGS needs to be well documented, clarifying medical necessity.

History of IGS

Richard Lebowitz, MD, Assistant Professor of Otolaryngology at the New York University School of Medicine, described some of the history behind the development of IGS. Original devices developed decades ago required rigid fixation of the head and were trajectory-based.

By the mid-1980s, frameless stereotactic surgery came into play, and had a position-sensitive articulated arm (wands). In the mid-1990s IGS progressed to having optical localizers, electromagnetic tracking, and were frameless, allowing for head mobility. At this point, the technology also no longer required use of wands, allowing for greater mobility of instruments.

Then there was a boom in technology, driven by surgeons’ needs, Dr. Lebowitz said. Recent years have seen several advances in endoscopic surgery devices. Now, IGS is used in revision surgery, extended frontal sinus surgery, tumor resection, skull base surgery, endoneurosurgery, and more.

Surgical instruments have become more refined as well. There are straight or curved microdebriders and drills, sinuplasty balloons, and frontal sinus and neurosurgical instruments.

Along with these are advances in CT, MRI, ultrasound, and fluoroscanning, each of which offers ever increasing details. Added to this, there is now the fusing of images, 3D volume rendering, and virtual image updates that are continually getting faster. Versions of these imaging devices are smaller and mobile, and can also be used intraoperatively.

IGS instrumentations now include compatible microdebriders-drills, universal instrument adapter systems, and even flexible instruments such as catheters and stents that can be used with hollow core sensors. In addition, ENTs have rotatable curved suction that does not require recalibration as the tip position changes.

We’ve seen big changes over the past decade, the next ten years will see even more more dramatic changes, said Dr. Lebowitz. One area to watch for is the development of robotic arms that can be used in conjunction with IGS. In future, it may open the door to things such as remote FESS, where the arm and patient are in one city, and the surgeon in another.

Limitations

The endoscope is a great instrument for us, but it’s not perfect, cautioned Brent Senior, MD, Chief of Rhinology, Allergy, and Sinus Surgery at the University of North Carolina, Chapel Hill. One difficulty lies in limits in the perspective the surgeon gets-along with problems of orientation and distortion.