A secondary learning curve in 3D versus 2D imaging in laparoscopic training of surgical novices

Stereoscopic (3D) imaging can be used to facilitate the learning of basic laparoscopic tasks. Its advantages over traditional endoscopic (2D) imaging include better depth perception and spatial orientation. However, the transition between 3D and 2D imaging systems has not been previously studied. This study compares the acquisition of basic laparoscopic skills in a laparoscopic-naïve population using both imaging systems, and explores the possibility of a secondary learning curve in the transition between systems.

26 novice learners were randomly allocated into two arms and taught to perform two basic laparoscopic tasks adopted from the fundamentals of laparoscopic surgery (FLS) curriculum, peg transfer (T1) and pattern cutting (T2) using either 2D or 3D imaging systems. These tasks were repeated until proficiency was achieved. Participants in each arm then repeated the tasks in the other viewing system (2D/3D vs 3D/2D). The parameters measured were: (a) time taken to complete the task and (b) number of attempts to achieve proficiency.

There was a significant shortening of time required to achieve proficiency in T2 using a 3D system (mean difference-in-differences =  - 65.4, 95% CI - 103.6 to - 27.2, t(24) =  - 3.5, p value = 0.002) but no difference between 2D and 3D imaging systems for T1, a simpler task. Sub-group analysis of T1 and T2 between the 2D/3D and 3D/2D arms showed the presence of a secondary learning curve in the 2D/3D arm for both tasks, (T1: β-estimate - 2.68, 95% CI - 3.68 to - 1.68, p value = 0.0003; T2: β-estimate - 2.45, 95% CI - 3.75 to - 1.14, p value 0.004), but in the 3D/2D arm there was a secondary learning curve only for T2. (β-estimate 2.60, 95% CI 1.45-3.76, p value 0.001) CONCLUSION: 3D imaging can be an effective tool to speed the acquisition of proficiency in basic laparoscopic tasks for novice learners, especially in more complex tasks such as pattern cutting. The skills learned in 3D imaging can translate into 2D, albeit with a secondary learning curve.