Background Robotic-assisted surgery (RAS) potentially reduces workload and shortens the surgical learning curve compared to conventional laparoscopy (CL). The present study aimed to compare robotic-assisted cholecystectomy (RAC) to laparoscopic cholecystectomy (LC) in the initial learning phase for novices. Methods In a randomized crossover study, medical students (n = 40) in their clinical years performed both LC and RAC on a cadaveric porcine model. After standardized instructions and basic skill training, group 1 started with RAC and then performed LC, while group 2 started with LC and then performed RAC. The primary endpoint was surgical performance measured with Objective Structured Assessment of Technical Skills (OSATS) score, secondary endpoints included operating time, complications (liver damage, gallbladder perforations, vessel damage), force applied to tissue, and subjective workload assessment. Results Surgical performance was better for RAC than for LC for total OSATS (RAC = 77.4 ± 7.9 vs. LC = 73.8 ± 9.4; p = 0.025, global OSATS (RAC = 27.2 ± 1.0 vs. LC = 26.5 ± 1.6; p = 0.012, and task specific OSATS score (RAC = 50.5 ± 7.5 vs. LC = 47.1 ± 8.5; p = 0.037). There were less complications with RAC than with LC (10 (25.6%) vs. 26 (65.0%), p = 0.006) but no difference in operating times (RAC = 77.0 ± 15.3 vs. LC = 75.5 ± 15.3 min; p = 0.517). Force applied to tissue was similar. Students found RAC less physical demanding and less frustrating than LC. Conclusions Novices performed their first cholecystectomies with better performance and less complications with RAS than with CL, while operating time showed no differences. Students perceived less subjective workload for RAS than for CL. Unlike our expectations, the lack of haptic feedback on the robotic system did not lead to higher force application during RAC than LC and did not increase tissue damage. These results show potential advantages for RAS over CL for surgical novices while performing their first RAC and LC using an ex vivo cadaveric porcine model. Registration number researchregistry6029 Graphic abstract

Introduction Although robotic-assisted surgery is increasingly performed, objective assessment of technical skills is lacking. The aim of this study is to provide validity evidence for objective assessment of technical skills for robotic-assisted surgery. Methods An international multicenter study was conducted with participants from the academic hospitals Heidelberg University Hospital (Germany, Heidelberg) and the Amsterdam University Medical Centers (The Netherlands, Amsterdam). Trainees with distinctly different levels of robotic surgery experience were divided into three groups (novice, intermediate, expert) and enrolled in a training curriculum. Each trainee performed six trials of a standardized suturing task using the da Vinci Surgical System. Using the ForceSense system, five force-based parameters were analyzed, for objective assessment of tissue handling skills. Mann–Whitney U test and linear regression were used to analyze performance differences and the Wilcoxon signed-rank test to analyze skills progression. Results A total of 360 trials, performed by 60 participants, were analyzed. Significant differences between the novices, intermediates and experts were observed regarding the total completion time (41 s vs 29 s vs 22 s p = 0.003), mean non zero force (29 N vs 33 N vs 19 N p = 0.032), maximum impulse (40 Ns vs 31 Ns vs 20 Ns p = 0.001) and force volume (38 N3 vs 32 N3 vs 22 N3p = 0.018). Furthermore, the experts showed better results in mean non-zero force (22 N vs 13 N p = 0.015), maximum impulse (24 Ns vs 17 Ns p = 0.043) and force volume (25 N3 vs 16 N3p = 0.025) compared to the intermediates (p ≤ 0.05). Lastly, learning curve improvement was observed for the total task completion time, mean non-zero force, maximum impulse and force volume (p ≤ 0.05). Conclusion Construct validity for force-based assessment of tissue handling skills in robot-assisted surgery is established. It is advised to incorporate objective assessment and feedback in robot-assisted surgery training programs to determine technical proficiency and, potentially, to prevent tissue trauma.

Background The aim of this study was to assess the transferability of surgical skills for the laparoscopic hernia module between the serious game Touch Surgery™ (TS) and the virtual reality (VR) trainer Lap Mentor™. Furthermore, this study aimed to collect validity evidence and to discuss “sources of validity evidence” for the findings using the laparoscopic inguinal hernia module on TS. Methods In a randomized crossover study, medical students (n = 40) in their clinical years performed laparoscopic inguinal hernia modules on TS and the VR trainer. TS group started with “Laparoscopic Inguinal Hernia Module” on TS (phase 1: Preparation, phase 2: Port Placement and Hernia Repair), performed the module first in training, then in test mode until proficiency was reached. VR group started with “Inguinal Hernia Module” on the VR trainer (task 1: Anatomy Identification, task 2: Incision and Dissection) and also performed the module until proficiency. Once proficiency reached in the first modality, the groups performed the other training modality until reaching proficiency. Primary endpoint was the number of attempts needed to achieve proficiency for each group for each task/phase. Results Students starting with TS needed significantly less attempts to reach proficiency for task 1 on the VR trainer than students who started with the VR trainer (TS = 2.7 ± 0.6 vs. VR = 3.2 ± 0.7; p = 0.028). No significant differences for task 2 were observed between groups (TS = 2.3 ± 1.1 vs. VR = 2.1 ± 0.8; p = 0.524). For both phases on TS, no significant skill transfer from the VR trainer to TS was observed. Aspects of validity evidence for the module on TS were collected. Conclusion The results show that TS brought additional benefit to improve performances on the VR trainer for task 1 but not for task 2. Skill transfer from the VR trainer to TS could not be shown. VR and TS should thus be used in combination with TS first in multimodal training to ensure optimal training conditions.