Functional and oncologic outcomes of robot-assisted simple enucleation with and without renal arterial cold perfusion in complex renal tumors: a propensity score-matched analysis

BACKGROUND: To compare robot-assisted simple enucleation with renal arterial cold perfusion (RACP-RASE) and RASE alone in complex renal tumors with regard to perioperative, functional and oncologic outcomes by propensity score-matched analysis. METHODS: Data from 351 patients who underwent RACP-RASE or RASE for complex renal tumors were recorded between September 2014 and December 2017. Propensity score-matched analysis was performed on age, sex, BMI, ECOG score, tumor side and size, preoperative estimated glomerular filtration rate (eGFR), RENAL score and PADUA score. RESULTS: The study included 31 RACP-RASE and 320 RASE procedures. RENAL score and PADUA score were higher and tumor diameter was greater under RACP-RASE than RASE. After matching, the two groups were similar in estimated blood loss (208.3 vs 230.7 ml; p = 0.696) and ischemic time (34.8 vs 32.8 min; p = 0.342). The RACP-RASE group had significantly longer operative time than the RASE group (264.1 ± 55.7 vs 206.9 ± 64.0 min, p = 0.001). There was no difference in the incidence of postoperative complications between the two groups (13.8% vs 24.1%; p = 0.315), as was the overall incidence of positive surgical margins (3.4 vs 0%; p = 1.000). The changes in eGFR significantly differed between the two groups at 3 months (p = 0.018) and 12 months (p = 0.038). More patients in the RASE group were CKD upstaged (p = 0.043). At multivariable analysis, preoperative eGFR and the type of procedure were significant predictive factors for a change of more than 10% in eGFR at 3 months postoperatively. There was no local recurrence or distant metastasis during follow-up. CONCLUSIONS: RACP-RASE is an effective and safe technique for complex renal tumors that can provide appropriate temporary arterial occlusion and renal hypothermic perfusion. Renal arterial cold perfusion may be helpful in protecting renal function in RASE as compared with warm ischemia.