Could trainees' finger placement at the surgeon's console affect overall outcomes of robotic surgery in radical prostatectomy? A prospective, blinded, robotic simulation pilot study.

Introduction: Robotic surgery for localized prostate cancer offers a greater range of motion attributed to the EndoWrist instruments. Postoperative outcomes are linked to the quality of vesico-urethral anastomosis. Trainees frequently complain of suturing difficulty in a back-handed fashion. We aimed to analyze wrist motion using the DaVinci simulator. We hypothesized that using the thumb and index finger would allow superior surgical proficiency when compared to the middle finger.

Methods: After institutional review board approval, we recruited 42 medical students in one academic medical center. Students were randomly assigned to start with their thumb and index finger (1&2) or thumb and middle finger (1&3). Three standardized modules were used with nine metrics calculated, including: score, total time, economy of motion, efficiency score, collisions, inaccurate puncture, wound approximation, out of view, and penalty subtotal. Statistical analysis of the metrics was calculated using SPSS.

Results: Three metrics were found to have differences between the finger placement of 1&3 compared to 1&2. The number of collisions, wound approximation, and penalty score where 1&3 were used had a lower score in each. The number of collisions was 5.7 less in the 1&3 finger placement (p=0.046). This metric was found to have statistically significant differences between finger placement where 1&3 had a lower score compared to 1&2. The wound approximation score was 0.2 points lower when using the 1&3 placement (p=0.075). Lastly, the penalty assigned was 6.5 points lower when using 1&3 (p=0.069).

Conclusions: Although finger placement did not affect the overall score of the completed simulation, instrument collisions and unnecessary wound complications may lead to adverse outcomes when using 1&2 despite offering a wider range of motion. This may be due to decreased comfort in hand position. Trainees may be able to improve the effectiveness of their vesico-urethral anastomosis during robotic-assisted radical prostatectomy.