Predicting morbidity after robotic partial nephrectomy: The effect of tumor, environment, and patient-related factors

Purpose: To investigate the effect of tumor and nontumor related parameters on perioperative outcomes of robotic partial nephrectomy (RPN).

Patients and methods: Patients who underwent RPN for a localized renal tumor at 2 institutions between June 2010 and November 2016 were reviewed. RENAL and Mayo adhesive probability (MAP) scores were calculated and information on comorbid conditions including ASA score, performance status, Charlson's comorbidity index (CCI), and history of cardiovascular disease was collected. Correlations between each variable and warm ischemia time, estimated blood loss (EBL), operative time, change in estimated glomerular filtration rate, and length of hospital stay were assessed. Logistic regression analyses were performed to identify the best predictors of overall complications, major complications, risk of conversion, and Trifecta achievement.

Results: A total of 500 patients were included. RENAL score was found to have a statistically significant (P<0.05) correlation with warm ischemia time, EBL, and change in estimated glomerular filtration rate. MAP score showed significant association (P<0.05) with operative time and EBL. CCI had a significant correlation (P<0.05) with length of hospital stay and postoperative complications. In multivariable analyses, MAP score as a continuous variable (OR = 7.66; P<0.001) and MAP risk group stratification (OR = 3.29; P = 0.005) were independent predictors of the risk of conversion. Major complications were significantly associated with the cardiovascular disease in both univariable (OR = 2.35; P = 0.01) and multivariable analysis (OR = 4.52, P = 0.01). Finally, the MAP score as a continuous variable was an independent factor of Trifecta achievement (OR = 0.56; P = 0.04).

Conclusion: Patients related factors were the most important determinants of postoperative complications after RPN. RENAL and MAP scores had some influence on intraoperative parameters.