Off-axis vs. on-axis training of laparoscopic skills

Study Objective: The advantages of laparoscopic simulators to enhance surgical skills have been well documented. Examples of trainers include box trainers with a webcam and desktop monitor or large high-cost virtual reality simulators. These options provide rigid setups that place the viewing monitor directly opposite the surgeon (on-axis). However, during the course of advanced laparoscopic surgery this monitor position is not always possible and off-axis setup is often used. This study aims to establish the need for offaxis training of laparoscopic skills through the use of a novel modular virtual reality simulator. Design: This was a multicenter cross-sectional study. Setting: Two large academic centers. Patients: Ob/Gyn residents, physicians, and graduate students. Intervention: Participants had varying experience with laparoscopic surgery. Subjects used the simulator to pull a virtual string taut and cut it in the center. The simulator scored performance using time to complete the task and the accuracy of the cut. Each participant performed a practice trial followed by four scored trials in each axis, once with the monitor on-axis and once with the screen off axis, 90 degrees to the left of the subject. Measurements and Main Results: Six novices (<10 surgeries) and 4 experienced (>=10 surgeries) were recruited. A one-way ANOVA was taken for both scenarios with the independent variable as the subject's experience, and dependent variable the score of the product of time to completion and accuracy. For on-axis trials, experienced subjects performed slightly better than novices [F = 3.22, p = .077]. For off-axis trials experienced subjects did not see a further drop in performance, whereas novice subjects showed markedly decreased performance [F = 5.02, p = .023]. Conclusion: This supports the recommendation that novice surgeons consider training in both on-axis and off-axis scenarios to better acquire advanced laparoscopic skills. Accordingly, trainers should be adapted to present a range of scenarios.