Mp59-18 predictive Factors of Long-Term Deterioration of Renal Function After Robot-Assisted Partial Nephrectomy-Analysis by Histopathological Findings of Preserved Kidney

Abstract

INTRODUCTION AND OBJECTIVE: Outcomes of 2 dedicated randomized controlled trials (RCTs) comparing on-clamp versus offclamp robot-assisted (RPN) or pure laparoscopic partial nephrectomy (LPN) (CLOCK I and II RCTs, respectively) have been published. Both in the LPN and in the RPN RCTs, shift from planned off-clamp to on-clamp approach occurred in some patients. We performed a cross-analysis between the trials, comparing perioperative outcomes of RPN vs LPN in these specific subgroups of patients.METHODS: For the purpose of the study, patients randomized to off-clamp and who were shifted to on-clamp RPN and LPN were extracted from CLOCK I and II RCTs, respectively (ClinicalTrials.gov NCT02287987). Univariate analysis of baseline data and perioperative outcomes was performed. Multivariable models were used to balance the effect of potential confounders on the results.RESULTS: 69 out of 164 (42.1%) and 41 out of 126 (32.5%) patients were shifted from off-clamp to on-clamp RPN and LPN (p[0.1) and extracted from the CLOCK I and II RCTs. At baseline, cohorts had comparable age, gender, BMI, comorbidities/performance status, hemoglobin, platelets count, PT/PTT, creatinine, eGFR, tumor size and RENAL score. Median tumor size was 3.5 vs 4 cm (IQR 2.7-4.4 vs 2.5-5, RPN vs LPN, respectively, p[0.4) and RENAL score 7 vs 7 (IQR 6-8 vs 5-8, p[0.6). No significant differences were noted as regarding approach (trans-versus retroperitoneal), resection technique as assessed by the SIB score and renorrhaphy technique. During RPN, AirSeal was more likely used (78% vs 2.4%, p<0.001). Hemostatic agents were more likely used during LPN (85.5% vs 100%, p[0.01). At univariate analysis, operative time, renorrhaphy time, drainage removal day, length of stay, and Clavien >2 complications favored RPN. 5 th postoperative day hemoglobin was higher after LPN (12 g/dl, IQR 10.9-12.8 vs 13 g/dl, IQR 12-13.7, p[0.01) although no significant differences were found in blood loss. No significant differences in renal function and positive surgical margins (4.5% vs 2.6%, p[1) were found. At multivariable analysis, AirSeal and hemostatic agents use mitigated for differences in operative time (p[0.02), suture time (p[0.001), drainage removal day (p<0.001), 5th postoperative day hemoglobin (p[0.002) and length of stay (p[0.01).CONCLUSIONS: Cross-analysis of two RCTs showed that robotics allows for more favorable perioperative outcomes when shifting from a planned off-clamp to an on-clamp approach during partial nephrectomy. Use of AirSeal and hemostatic agents seemed impacting on such differences.