ENDOSCOPIC ROBOT-ASSISTED SIMPLE ENUCLEATION (ERASE) VS. OPEN SIMPLE ENUCLEATION (OSE) FOR THE TREATMENT OF CLINICAL T1 RENAL MASSES: ANALYSIS OF PREDICTORS OF TRIFECTA OUTCOME

Aim: The aim of this study was to analyse the intra- and postoperative complications, as well as the predictive factors of Trifecta outcome in patients submitted to endoscopic robotassisted simple enucleation (ERASE) and open simple enucleation (OSE) for clinical T1 renal masses. Materials and Methods: Overall, 634 cases treated with OSE (n=290) and ERASE (n=344) were prospectively recorded in our Department between 2006 and 2014. Trifecta was defined as simultaneous ischemia time <25 min, no surgical complication and negative surgical margin. A univariate analysis and multivariate logistic regression were performed for Trifecta. Results: The two groups were comparable for body mass index (BMI), comorbidity, tumor side, clinical T score, tumor diameter, surgical indication, pre-operative renal function, pre-operative hemoglobin and hematocrit. A significant difference was found between the OSE and the ERASE groups in operative time (115 (96-130) vs. 150 (120- 180) minutes, p<0.0001), pedicle clamping (93.8% vs. 69.2%, p<0.0001), estimated blood loss (EBL) (150 (100- 200) vs. 100 (100-143) cc, p<0.0001) and intraoperative complications (3.4% vs. 1.7%, p=0.02). The two groups were comparable for warm ischemia time (WIT) ≥25 min. A significant difference was found between OSE and ERASE in overall (16.6% vs. 5.5%, p<0.0001), Clavien 2 (11.7% vs. 4.4%, p=0.02) and Clavien 3 (3.1% vs. 1.7%, p=0.04) postoperative surgical complications, length of stay (6.0 (5.0-7.0) vs. 5.0 (4.0-6.0) days, p<0.0001), pre-operative 1st day delta creatinine (0.3 (0.2-0.4) vs. 0.15 (0.1-0.2) mg/dl, p<0.0001), positive surgical margins (2.1% vs. 1.5%, p=0.04), and Trifecta achievement (73.8% vs. 85.5%, p<0.0001). At univariate analysis, a higher median clinical diameter, a higher mean age, a higher median Charlson comorbidity index (CCI), endophytic tumor growth pattern, renal sinus and calyceal dislocation of the tumor, a higher median PADUA score and OSE were predictive factors of Trifecta achievement. At multivariate analysis, CCI lost significance (p=0.26), while age (odds ratio (OR)=1.02, 95% confidence interval (95% CI)=1.00-1.04, p=0.001), clinical diameter (OR=1.22, CI=1.05-1.42, p=0.008), PADUA score (OR=1.23, CI=1.07-1.41, p=0.004) and OSE (OR=1.74, CI=1.13-2.68, p=0.01) were confirmed predictive factors for Trifecta failure. Conclusion: The ERASE is a feasible and safe technique, which shows a comparable WIT, together with a significantly lower EBL, surgical complications’ rate, length of stay and a significantly higher Trifecta achievement compared to OSE. Age, comorbidity, tumor diameter and PADUA score, in association with surgical approach, represent significant predictive factors of Trifecta failure.