Surgical fidelity: comparing the microscope and the endoscope

Background: Both the microscope and the endoscope are widely used as visualization tools in neurosurgery; however, surgical dexterity when operating with endoscopic visual control may differ. The aim of this study was to compare the surgical fidelity when using each of these visualization tools. Methods: Junior residents and expert surgeons performed standardized motor tasks under microscopic and endoscopic visualization. Demerits for inaccuracy and time needed to complete the tasks were used to compare the surgeons' performance with the microscope and the endoscope. The participants also performed a motor task under direct vision using different instruments to evaluate whether the shape of the instrument had any impact on the surgical fidelity. Results: For the junior residents, the number of demerits accrued was lower with the microscope than with the endoscope, and the time needed to complete the tasks was also lower with the microscope. There was no difference in the number of demerits between the microscopic and the endoscopic experts, but the microscopic expert completed the task in a shorter time. There was no difference in demerits or performance time when comparing a short, straight instrument and a longer, bayoneted one. Conclusion: For junior residents, surgical fidelity is higher with the microscope than with the endoscope. This difference vanishes with experience, but a slower speed of execution is observed with endoscopic visualization, both in junior and expert surgeons.