Intra-operative image guidance in otolaryngology--the use of the ISG viewing wand

The ISG viewing wand is an intra-operative guidance system with a proprioceptive robotic-like jointed arm. It provides surgeons with almost instantaneously reconstructed computer-generated CT or MRI images in two or three dimensions and can correlate any point within the operative field to its corresponding locus on the reformatted scan images. In addition to having been used in over 400 neurosurgical patients in Bristol, 14 patients with skull-base, cerebello-pontine angle or temporal bone lesions have also undergone wand-guided resections. The wand has proved to be particularly useful in pre-operative planning, allowing minimally-invasive incisions, providing per-operative navigation, identifying the relationship and proximity of important anatomical structures and in assessing the extent of lesion resection. We illustrate the advantages of intra-operative image-guidance by discussing four cases. The potential applications of this form of imaging technology to other otolaryngological procedures are discussed.