Evolution of Robot-assisted Partial Nephrectomy: Techniques and Outcomes from the Transatlantic Robotic Nephron-sparing Surgery Study Group.

Background: Robot-assisted partial nephrectomy (RAPN) is considered a feasible minimally invasive alternative to open partial nephrectomy (OPN) for the surgical treatment of renal tumors.

Objective: To provide further evidence supporting the effectiveness of RAPN in a contemporary patient population treated at one of three tertiary care centers for robotic surgery and to describe the evolution of RAPN-based technical improvements.

Design, Setting, And Participants: The Transatlantic Robotic Nephron-sparing Surgery (TRoNeS) study group prospectively collected data from 635 patients subjected to RAPN for clinically localized kidney cancer between 2010 and 2016 at three high-volume tertiary care centers.

Surgical Procedure: RAPN was performed using methods outlined in the supplementary video using either the da Vinci Si or Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA).

Measurements: Clinical data were collected within a prospectively maintained multi-institutional database. Intra- and postoperative data as well as surgical outcomes were assessed. Descriptive statistical analysis was performed and multivariable logistic regression models were fitted to determine the predictors of surgical outcomes.

Results And Limitations: Mean patient age was 60.7yr and mean preoperative tumor size was 33mm. According to the PADUA score, 202 (31.8%) patients had a low-, 235 (37.0%) had an intermediate-, and 198 (31.2%) had a high-complexity tumor. In the majority of patients, a transperitoneal approach was used (n=447; 70.4%). Mean operative time was 156.3min and mean estimated blood loss was 171ml. Overall, 25 (3.9%) patients experienced a significant (Clavien-Dindo >2) complication after surgery. No statistically significant differences between pre- and postoperative creatinine values were observed (p≤0.823). Finally, optimal surgical outcomes defined according to the margin, ischemia, and complication score were achieved in 459 (72.3%) individuals. At a mean follow-up of 26mo, only two local and two distant recurrences of the disease were observed. Finally, in multivariable logistic regression models, tumor complexity was associated with the risk of not achieving optimal surgical outcomes.

Conclusions: RAPN represents an effective minimally invasive alternative to OPN in the treatment of clinically localized renal tumors.

Patient Summary: We reported contemporary experience with RAPN for the treatment of kidney cancer. RAPN appears to be a safe and effective procedure, resulting in optimal outcomes in the majority of individuals despite tumor complexity.