The role of the assistant during robot-assisted partial nephrectomy: does experience matter?

The objective of this study was to evaluate surgical outcomes with respect to the experience level of the bedside assistant during robot-assisted partial nephrectomy. A retrospective review was conducted of a prospectively maintained database of 414 consecutive robot-assisted laparoscopic partial nephrectomies performed by experienced robotic surgeons at our institution from April 2011 to September 2014. A senior-level assistant was defined as a resident in his or her post-graduate year (PGY) 4 or 5, or a fellow. Junior-level assistants were considered to be PGY-2, PGY-3, or a nurse first assistant. Multivariate analyses were performed using linear, Poisson, and logistic regression models. There were 115 junior-level cases and 299 senior-level cases. On univariate analysis, the experience level of the assistant had no impact on operative time (168 for junior level vs. 163 min for senior level, p = 0.656). Likewise, there were no differences between the junior- and senior-level groups with regard to warm ischemia time (21.3 vs. 20.9 min, p = 0.843), negative margin status (111/115 (96.5 %) vs. 280/299 (93.6 %), p = 0.340), or postoperative complications (17/115 (14.8 %) vs. 35/299 (11.7 %), p = 0.408). After multivariate analysis, operative time was associated with increased body mass index and tumor size (both p < 0.001), but not with resident experience level (p = 0.051). Estimated blood loss and postoperative complications were also not associated with the PGY of the assistant (p = 0.488 and p = 0.916, respectively). Despite common concern, the PGY status of a physician trainee serving as the bedside assistant does not appear to influence the outcomes of robot-assisted partial nephrectomy at a high-volume center.