Off-axis microsurgical training using combined exoscopy and endoscopy in a cerebral aneurysm model

Recently, endoscopes have been increasingly used to visualize and inspect blind areas of cerebral aneurysms that are difficult to observe directly during microsurgery. Exoscopes are well suited for endoscope-assisted surgery because they provide a wide working space without the obstruction of a large microscope barrel. In addition, surgeons can view both the exoscopic and endoscopic images with minimal gaze shift.

We developed cerebral aneurysm models for training in aneurysm dissection and clipping using combined exoscopic and endoscopic visualization. The main exoscopic monitor was aligned with the Sylvian fissure, and the endoscopic monitor was positioned adjacent to it. The endoscope was inserted from a different trajectory than the exoscopic surgical approach to directly visualize the posterior aspect of the aneurysm. Visualization and maneuverability were evaluated.

Combined exoscopic and endoscopic visualization from different viewing angles enabled dissection and clipping under direct visualization without blind manipulation. However, performing dissection and clipping under endoscopic visualization from an off-axis perspective required considerable practice. Surgical rehearsal using the aneurysm model was effective for understanding the technical aspects of off-axis manipulation.

The cerebral aneurysm model enabled realistic rehearsal of combined exoscopic and endoscopic aneurysm clipping without practicing on patients. This approach may expand the potential of multi-monitor surgery integrating exoscopy and endoscopy, including future robotic neurosurgical procedures.