Three-Dimension Images in Endoscopic Endonasal Anatomical Dissection: An Innovative Method

Background: From its insertion, one of the main criticisms to endoscopic endonasal surgery was the two-dimension of visualization in contrast to the 3-dimension provided by the microscope. There is a need to study the skull base anatomy with an endoscopic perspective in three-dimension imaging. At present, there are two methods to obtain tridimensional stereo images in high definition. The Side-by-Side or simultaneous methods require highly specialized hardwares, needs a 3D PC or 3D TV and proper glasses. Conversely, the Anaglyph Red/Cyan 3D method requires less specialized hardware and can be directly utilized in publications. We propose a simple technique to obtain tridimensional pictures in cadaveric studies from a conventional endoscopic dissection adopting the Anaglyph Red/Cyan 3D technology.

Methods: The endoscope was fixed on a frame, which allows the operator to move it on a straight line only in the coronal plane. The method requires a recording system, an endoscopic system: full HD microscope camera head with a resolution specified for 1080p Full HD (1920 × 1080 pixels), zero degrees endoscope and a smartscreen imaging system. The first picture (corresponding to right eye perception) was performed, keeping the target on the center of the field. The endoscope is lthen moved a variable distance, which depends on the depth, size and the focus distance of the target, until the target is in the edge of the field. Finally, the endoscope was angled to re-locate the target in the center of the field then the second picture (corresponding to left eye) was taken. At the end, the two pictures were elaborated through a specific software (open source software) to create the tridimensional effect with the Anaglyph Red/Cyan 3D Technologies. Both images can also be used in teaching sections using polarized light for projection of 3D pictures.

Results: This method was tested to take tridimensional pictures of the main anatomical skull base structures in five fixed heads (four injected). The methods resulted fast, useful and replicable. The possibility to calculate the distance between the first and second picture, to do exactly movements of the endoscope allows us to standardize the technique and obtain good tridimensional images with satisfactory resolution and depth perception.

Conclusions: The proposed method resulted effective and quick to obtain tridimensional picture during endoscopic endonasal cadaveric dissection. The low cost of the necessary materials and the high replicability gives this method a great potential to widely spread in the main endoscopic endonasal anatomical centers in the world.