Comparison of laparoscopic performance in vivo with performance measured in a laparoscopic simulator

Laparoscopic skill was measured objectively through a series of seven tasks in an inanimate laparoscopic simulator. Seven analogous skills were tested in an in vivo porcine model. These skills included transferring, cutting, clipping, placement of a ligating loop, mesh placement, and suturing with an intracorporeal and extracorporeal knot. Scoring of each task rewarded precision and speed.

Twelve PGY3 residents were given a baseline evaluation in the simulator and in the animal model. They were then randomized to either five practice sessions in the simulator (group A) or no practice (group B). Each group was retested in the simulator and in the animal (final test). Scores in vivo were compared by t-test for baseline versus final evaluation for each group. Linear regression analysis was used to correlate in vivo and in vitro scores for each task and for the total score (sum of all scores).

Group A showed significant improvement in performance in vivo for cutting, clipping, mesh placement, and suturing with an intracorporeal and extracorporeal knot, as well as in the total score (p < 0.05). Group B showed significant improvement in suturing with an intracorporeal and extracorporeal knot, and in the total score. The magnitude of improvement from baseline to final evaluation was significantly greater for group A (p < 0.05). There was significant correlation between in vitro and in vivo total scores and the score for each task (p < 0.05) except for placement of the ligating loop and mesh.

Performance in an in vitro laparoscopic simulator correlated significantly with performance in an in vivo animal model. Practice in the simulator resulted in improved performance in vivo.