3D vs. 2D-4 K: Performance and self-perception of laparoscopic novices in a randomized prospective teaching intervention using standard tasks and box trainers
Authors: Kölbel Benny , Ragnitz Julian , Schäle Kevin , Witzenhausen Moritz , Axt Steffen , Beltzer Christian 
Published: October 2024

Abstract
Objective
The use of three-dimensional (3D) laparoscopy in surgical practice and training has been an area of research and discussion. Studies have suggested that 3D vision can improve speed and precision compared to traditional two-dimensional (2D) displays, while other authors found no benefits on the learning curves of laparoscopic novices. Modern two-dimensional laparoscopy with a resolution of 3840 × 2160 pixels (2D-4 K) seems to improve laparoscopic view and helps learners orient without stereopsis. However, evidence comparing these systems for laparoscopic training is limited. Therefore, the impact of viewing mode (2D-4 K vs. 3D) on learning and task proficiency remains unclear.

Design
We performed a two-hour teaching intervention on basic laparoscopic skills for novices. In this parallel group randomized study, we randomly assigned learners to 2D-4 K or 3D teaching and performed tasks of increasing difficulty and complexity using standard laparoscopy box trainers. Before the last and most challenging task, learners had to crossover to the other laparoscopy setup. Our hypothesis was that learners would be faster and more precise when using a 3D setup. The primary endpoint was task proficiency measured by speed and failure rate. Secondary outcomes were performance using the viewing mode of the other group without familiarization, self-perception, and career aspirations before and after the teaching intervention, expressed on a Likert scale.

Setting
The study was performed by the Department of General, Visceral and Thoracic Surgery at the German Armed Forces Hospital Ulm, which is an academic teaching hospital of the University of Ulm.

Participants
Thirty-eight laparoscopic novices, including medical students and junior residents, participated voluntarily in this teaching intervention. Group allocation was performed via the virtual coin flip method. Apparently, participants and tutors were not blinded to group assignment. No formal approval by the ethics committee was needed for this noninvasive study in compliance with the World Medical Association Declaration of Helsinki as discussed with the ethics committee of the University of Ulm.

Results
Thirty-eight laparoscopy novices were randomized in the study. The 3D group (n = 19) was significantly faster than the 2D-4 K group (n = 19) (p = .008) in a standard box trainer model, with 134.45 ± 41.45 s vs. 174.99 ± 54.03 s for task 1 and 195.97 ± 49.78 s vs. 276.56 ± 139.20 s for task 2, and the effect was consistent throughout the learning curve. The failure rate was not significantly affected by the viewing mode. After crossover to the other laparoscopy system, precision and time were not significantly different between the groups. Learners rated the difficulty of laparoscopy lower on a Likert scale after having two hours of basic laparoscopy training. The study was funded by the hospital’s teaching budget.

Conclusions
Laparoscopic novices can benefit from a 3D laparoscopy training setup. Exclusive 3D training prior to a complex task on a 2D-4 K setup does not negatively affect the learner’s performance.