Margin, ischemia, and complications system to report perioperative outcomes of robotic partial nephrectomy: a European Multicenter Observational Study (EMOS project).

Objective: To explore the margin, ischemia, and complications (MIC) system achievement rate within a population of patients who were treated with robotic partial nephrectomy (RAPN), at 3 different tertiary care centers, and to determine the factors predicting MIC achievement.

Methods: The study population consisted of 339 patients who underwent RAPN for cT1 renal tumors at 3 centers. Cancer control was defined as the absence of positive surgical margin. Ideal threshold of warm ischemia time (WIT) was considered ≤20 minutes. Safety was defined as the absence of major complications. The achievement of MIC was considered as the fulfillment of all these 3 outcomes. The primary endpoint was to determine the MIC rate in our study population; the secondary endpoint was to detect factors affecting its achievement.

Results: The overall MIC rate was 67%. Median WIT was 17 minutes (range, 7-51 minutes). In 88 cases (26%), WIT was >20 minutes. Positive surgical margins were found in 22 patients (6.5%). Overall postoperative and major complication rates were 14.5% (n = 49) and 3.8% (n = 13). In multivariate logistic regression analysis, continuously coded and categorically coded preoperative aspects and dimensions used for an anatomical scores were an independent predictor of MIC achievement (odds ratio, 0.636; confidence interval, 0.436-0.928; P = .019 and odds ratio, 0.098; confidence interval, 0.030-0.326; P <.001).

Conclusion: The MIC binary system may represent a useful tool to summarize the achievement of optimal perioperative outcomes of RAPN. In the current population, tumor complexity was significantly associated with MIC achievement.