A prototype variable corresponding to the proportion of ischemia for the comparison between robotic and open partial nephrectomy: a meta-analysis accompanied by sensitivity analysis

Background The primary objective of this study involves the formulation of a novel variable, derived from initial data related to ischemia duration and operative time in partial nephrectomies. The aim was to determine the proportion of ischemia for the comparison between robotic and open approaches in terms of their relative ischemic requirements. Main body The literature search was conducted from August 2022 to June 2023, primarily encompassing non-randomized comparative studies in the English language. Ultimately, a total of 62 studies involving data from 26,072 patients were included. Following appropriate transformation of the original data under the assumption of normal distribution, the proportion of ischemia ( I ) was formulated for each study and comparison arm, using estimator functions. Subsequent analysis of the generated data was performed for both the original variables and the I outcome. Statistical significance was only observed regarding the surgical duration, with a mean difference of 19.74 min (CI 95% = [11.56; 27.92]) in favor of robotic access. The mean difference in I was estimated on the entire dataset as well as carefully selected subgroups based on publication year, patient matching, the number of referral centers, and risk of bias class. Additionally, meta-regression analysis and four-level sensitivity analysis were conducted. In none of these investigations did statistically significant differences emerge between the two surgical approaches. These findings lead us to hypothesize that the proportion of ischemia in partial nephrectomies may represent an inherent characteristic of the procedure, typically manifesting as baseline ischemia (12–13% of operative time), with fluctuations depending on the chosen strategy or the complexity of the specific intervention. Short conclusion There is no difference in the proportion of ischemia between robotic and open partial nephrectomies. In overall, ischemia time appears to be primarily determined by the overall duration of the procedure and the effectiveness in achieving adequate hemostasis.