A comparative study on trocar configurations and the use of steerable instruments in totally extraperitoneal inguinal hernia surgery training

Abstract

Background: Totally extraperitoneal (TEP) inguinal hernia surgery is a commonly performed but technically challenging procedure with a long learning curve. As TEP can be executed using two different trocar placements: a midline or a triangular configuration, the question remains which one is technically easier to master. Methods: In a multicenter crossover-study, medical students were randomised into two groups and executed tasks on a box trainer that measured time, volume and force parameters. Additionally, the study assessed whether the SATA instrument, a steerable laparoscopic instrument that articulates the instrument’s tip, would reduce the difficulty of performing the tasks in the midline configuration. After training, all participants executed a first experiment using both trocar configurations, followed by a second experiment executed with steerable and non-steerable instruments in the midline configuration. Subjective and objective performances per condition and learning curves were assessed. Results: Participants were faster and showed lower peak forces in the triangulated configuration. Learning curve analysis showed a positive improvement in time and path length in the midline configuration. Although participants rated ergonomics and intuitiveness similarly between the instruments, they found the task easier with the SATA instruments, ranking the added value of the steering function as 5 out of 5. Objectively, time and path length showed no significant differences while exerted forces were lower when using conventional instruments. Conclusion: Although the midline configuration is preferred in terms of comfort and posture, the findings indicate that, for inexperienced practitioners, performing TEP surgery in midline configuration is both subjectively and objectively more challenging, highlighting the need for extensive training to overcome its difficulties and possibly shorten its learning curve. Although instruments with additional steering functions were preferred over conventional instruments in the more challenging midline configuration, additional steering complexity did not result in better parameter outcomes, showing the need for more extensive training.