Evaluation of new motorized articulating laparoscopic instruments by laparoscopic novices using a standardized...

Motorized articulating laparoscopic instruments (ALI) offer more degrees of freedom than conventional laparoscopic instruments (CLI). However, a difficult learning curve and complex instrument handling are still a problem of ALI. We compared the performance of new prototypes of motorized ALI with CLI in a series of standardized laparoscopic tasks performed by laparoscopic novices. Further, usability of the new ALI was assessed.

A randomized cross-over study with 50 laparoscopic novices who either started with CLI and then changed to ALI (CA) or vice versa (AC) was conducted. All participants performed the European training in basic laparoscopic urological skills (E-BLUS) with each instrument in given order. Time and errors were measured for each exercise. Instrument usability was assessed.

Overall, using CLI was significantly faster (CLI 4:27 min vs. ALI 4:50 min; p-value 0.005) and associated with fewer exercise failures in needle guidance (CLI 0 vs. ALI 12; p-value 0.0005) than ALI. Median amount of errors was similar for both instruments. Instrument sequence did not matter, as CA and AC showed comparable completion times. Regarding the learning effect, participants were significantly faster in the second attempt of exercises than in the first. In the needle guidance task, participants using CLI last demonstrated a significant speed improvement, whereas ALI were significantly slower in the second run. Regarding usability, CLI were preferred over ALI due to lighter weight and easier handling. Nevertheless, participants valued ALI's additional degrees of freedom.

Using new motorized ALI in the E-BLUS examination by laparoscopic novices led to a worse performance compared to CLI. An explanation could be that participants felt overwhelmed by ALI and that ALI have an own distinct learning curve. As participants valued ALI's additional degrees of freedom, however, a future application of ALI could be for training purposes, ideally in combination with CLI.