Three-dimensional endoscopic sinus surgery: Feasibility and technical aspects

The development of endoscopic techniques for a variety of sinonasal disorders has paralleled advances in technology and instrumentation including angled endoscopes, multi-chip cameras, and image guidance. Despite the progressive technological innovations in modern endoscopic surgery, the visualization that is currently used remains 2-dimensional (2D). This is associated with significant limitations, notably a lack of depth perception. Although visual and haptic cues allow for a surgeon to understand the spatial relationships of the various structures, current visualization technology fails to provide the 3-dimensional (3D) perspective that is available in open and microscopic surgery. The development of a miniature stereoscopic camera and its adaptation to rigid endoscopes allows for performance of 3D endoscopic sinus surgery. It is hypothesized that incorporation of 3D visualization may enhance the spatial resolution required in advanced endoscopic approaches with a theoretical potential to improve outcomes. TECHNOLOGY Following Institutional Review Board approval and a trial in a cadaver laboratory, a prospective study of 3D endoscopic sinus surgery with a miniature stereoscopic camera (Visionsense Ltd, Petach Tikva, Israel) was carried out. All patients underwent fully endoscopic, endonasal approaches to the anterior skull base with a 6.5 mm, 3D 0 degree stereoscopic endoscope (Figs 1 and 2). The procedures were performed by the senior authors (VKA, THS). The endoscope was used for the entire sinonasal approach and select portions of the intracranial aspect of the procedure. At the time of the study, only a 0 degree 3D endoscope was available. Angled 2D endoscopes were, therefore, also used for suprasellar and lateral visualization. Twelve patients underwent endoscopic, endonasal, transsphenoidal surgery during this study. The indication for surgery included pituitary lesions in nine cases, cerebrospinal fluid leaks in two patients, and craniopharyngioma in one patient. Bilateral transnasal sphenoidotomies were carried out in each patient with the 3D endoscope. One patient additionally underwent a complete ethmoidectomy for further visualization of a spheno-ethmoidal encephalocele. There were no intraoperative or postoperative complications noted during the study. Qualitative assessments by the surgical team revealed improved depth perception and improved recognition of anatomic structures especially the carotid artery and optic nerve prominences in the lateral sphenoid wall. There was no subjective increase in the operative time with the incorporation of the 3D endoscopes.