Video Learning of Surgical Procedures: A Randomized Comparison of Microscopic, 2- and 3-Dimensional Endoscopic Ear Surgery Techniques.

BACKGROUND

Video learning of surgical procedures helps trainees gain an initial understanding of the complex anatomy and the surgical procedure. Because no comparative studies have yet examined which microsurgical approach to the middle ear is most suitable for video learning, the authors investigated objective and subjective outcomes for medical trainees observing microscopic, 2-dimensional (2D) endoscopic, and 3- dimensional (3D) endoscopic ear surgeries.

METHODS

Sixty-two medical students (min. 3rd year) from the University Hospital of Bern watched three standardized videos of a type I tympanoplasty surgery recording, conducted with a microscope, a 2D endoscope, and a 3D endoscope, respectively. The authors measured participants' learning outcome, eye movements, cognitive load, and subjective preferences.

RESULTS

Of the 62 participants included in the study, 14 were male (22.58%), and mean age was 24.44 years (range: 21-29). Learning outcome was highest after watching the 3D endoscopic video (mean [SD], 59.48% [20.57%]). Differences in score were statistically significant: 2D endoscopic video (mean difference: -6.56%, 95% CI: -13.02 to -0.10%), microscopic video (mean difference: -13.82%, 95% CI: -20.27 to -7.36%). Participants showed lowest average eye fixation duration when watching the 3D endoscopic video (mean [SD], 307 ms [109 ms]), with statistically significant differences to the 2D endoscopic video (mean difference: -139 ms, 95% CI: -185 to -93 ms), and the microscopic video (mean difference: -264 ms, 95% CI: -310 to -218 ms). Participants reported lowest cognitive load for the 2D and 3D endoscopic videos. Ratings on discomfort, usability, naturalness, depth perception, and image quality were in favor of the 3D endoscopic video.

CONCLUSION

The 3D endoscopic technique offers many advantages for video learning in terms of knowledge gain, visual field exploration, and subjective evaluation. To optimize learning effects in trainees, the authors recommend the use of endoscopes in middle ear surgery and, if available, using 3D technology.