Intracorporeal Suturing: Economy of Instrument Movements Using a Box Trainer Model

Abstract

Study Objective To determine whether economy of instrument movement can differentiate between skills levels during intracorporeal suturing using a box trainer model. Design Prospective cohort study (Canadian Task Force classification II-2). Setting Skills laboratory of a university teaching hospital. Subjects Forty-two volunteers participated including 19 medical students without previous laparoscopic experience (novices), 12 residents in obstetrics and gynecology (intermediates), and 11 practitioners of intracorporeal suturing who had performed at least 200 laparoscopic procedures including advanced surgery (experts). Interventions Each participant performed 3 consecutive standardized intracorporeal sutures using a box trainer, and instrument movements were recorded using the TrEndo tracking device. Measurements and Main Results Time, path length, motion in depth, and motion smoothness of the instrument tips were recorded. Performance in the 3 groups differed significantly (p <.001 for all parameters; Kruskal-Wallis test). Experts outperformed novices in all 4 parameters (p <.01; Bonferroni test). Conclusion The construct validity has been suggested for time, path length, motion in depth, and motion smoothness for assessment of the laparoscopic suturing task using a box trainer. An expert level has been set for training and assessment purposes. The addition of economy of movement to time to complete the task has the potential to refine acquisition of skills.