Background/Aim: Trifecta represents a composite outcome reflecting the quality level of treatment in nephron sparing surgery. However, there is substantial heterogeneity concerning the criteria required for its fulfilment. The present study aimed to highlight the potential of a unified view for the different definitions of trifecta when comparing robotic and open approaches in partial nephrectomy. Materials and Methods: A systematic literature search was carried out for all relevant comparative studies published until April 2022. Trifecta definitions were clustered according to two criteria for postoperative renal function reduction. The first set as an upper limit the 10% decrease in the estimated glomerular filtration rate, while the second set as an upper limit 25 min of ischemia. To mathematically investigate the point of intersection between the above two groups, a suitable model of volume conservation equations was formulated. Results: A total of 11 studies were investigated for their methodological features and grouped accordingly. The ischemic zone volume surrounding the tumor resection site emerged as the central parameter connecting the two main definitions. Specifically, for patients with solitary renal masses, a given change in the value of one parameter resulted in a fixed change in the value of the other. Conclusion: The two main definitions of the "trifecta outcome" extracted from the international literature represent the two sides of the same coin. Thus, trifecta achievement rates could be utilized by future studies as aggregate data to yield a quantitative estimate of the comparative effect between robotic and open approaches in partial nephrectomy procedures.

Background The incidence of mild postoperative complications has been shown to be strongly associated with the beneficial effects provided through minimally invasive surgery. The main objective of the present study was to compare robotic and conventional open partial nephrectomy in terms of the incidence of mild postoperative complications. Main body The literature search process included all the comparative studies identified up to April 2022. Inclusion criteria concerned studies published in English, involving exclusively adult patients with solitary or multiple renal masses, who underwent robotic/robot-assisted or open partial nephrectomy. As mild postoperative complications, were defined those of Clavien–Dindo grade ≤ II. The meta-analysis included a total of 16 studies (3238 patients) and was also supplemented by appropriate subgroup analysis and meta-regression analysis to investigate for any additional sources of heterogeneity. Pooled data analysis revealed a statistically significant advantage with the adoption of the robotic approach (petoOR = 0.52, CI95% [0.43; 0.64]), while similar results were obtained from the analysis of the subgroups of studies with or without patient matching, those conducted in a single or multiple centers, as well as those published after 2015. From meta-regression, a time-independent superiority of robotic over open partial nephrectomy emerged, characterized by a tendency to broaden over the years. This finding was attributed to inherent features of robotic technology, the utilization of which is optimized in the context of its wider adoption in current kidney surgery practice. Short conclusion The main conclusion that can be drawn implies the clear superiority on the part of robotic partial nephrectomy over open surgery, in reducing the incidence of mild postoperative complications.