Ergonomic comparison of laparoscopic hand instruments in a single site surgery simulator with novices

Background: Single-site surgery improves cosmesis but increases procedural difficulty. Enhanced instruments could improve procedural efficiency leading to better patient outcomes. Material and methods: One pair of non-articulating (straight) and two different pairs of articulating laparoscopic instruments were evaluated using a peg-transfer surgical task simulator by premedical college students. The instruments were comparatively tested using task performance measures, ergonomic measures, and participant questionnaires. Results: The straight instrument produced significantly higher task performance scores and lower task times compared to both articulating instruments (p < 0.05). The straight instrument required less muscle activation and less wrist deviation than the articulating instruments to perform the same task. Participants rated the straight instrument significantly easier to use and less difficult to complete the task than with either articulating instrument (p < 0.05 for both). Conclusions: This exploratory study suggests that novices have difficulty using articulating instruments and perform better using straight laparoscopic instruments when first attempting LESS surgical tasks. Although a study with post-graduate medical trainees is needed to confirm these results, trainees should initially practice LESS with non-articulating instruments to gain proficiency at basic laparoscopic tasks. Additionally, redesigning articulating instruments to specifically address the spatial constraints and learning curve of LESS may also improve trainee performance and instrument usability.