Application of a three-dimensional intraoperative navigational system in craniofacial surgery

Recent advances in imaging technology have prompted the development of new instrumentation that permits direct interactive visualization of image data in the operating room. The ISG Viewing Wand (ISG Technologies, Mississauga, Ontario, Canada) is a frameless stereotactic system that combines three-dimensional computer-assisted imaging with a hand-guided, position-sensing, articulated arm. In this article we describe the use of the ISG Viewing Wand as a three-dimensional intraoperative navigational system in craniofacial surgery and review our initial clinical experience in 17 patients. The wand was used as an aid in the correction of craniofacial asymmetry in 12 patients and as a navigational device assisting in craniofacial skeletal resection in 5 patients. By orienting the surgeon to his exact location throughout the procedure, the ISG Viewing Wand was found to be useful in defining intraorbital anatomy, in determining ocular globe position, and in delineating tumor margins. Excellent anatomical spatial correlation was obtained, and the probe tip position was within 2 mm of its actual position in all cases. Use of the system added minimal additional time, and overall no adverse effects were attributed to use of the wand.