Functional & Trifecta Outcomes in Solitary Kidney: Unclamped vs Clamped Partial Nephrectomy

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INTRODUCTION AND OBJECTIVES: To assess renal functional and trifecta outcomes of clamped versus unclamped minimally invasive partial nephrectomy in patients with a solitary kidney.
METHODS: We retrospectively analyzed data of 129 patients undergoing PN in solitary kidney at 2 high-volume referral centers (1999-2014). PN was performed either by clamped technique or by unclamped technique. Trifecta after PN was achieved when eGFR decreased <10% from baseline, cancer margins were negative and there were no urological complications. RESULTS: CC-PN and UC-PN were performed in 64 and 65 patients, respectively. Mean tumor size (3.4 vs 3.9 cm, p=0.13) and baseline eGFR (60 vs 57, p=0.34) were similar between groups. Robotic PN was more frequent in the UC-PN (17% vs 69%, p<0.001). UC-PN patients had shorter mean warm ischemia time (WIT; 24 vs 0 min, p=<0.001) and operative time (4.3 vs 3.7 hrs, p=0.04). Perioperative outcomes were similar between CC-PN vs UN-PN groups: mean estimated blood loss (514 vs 285 cc, p=0.40), hospital stay (7.4 vs 4.9 days, p=0.86) and transfusion rate (28% vs 15 %, p=0.09). Overall complications trended to be lower for UN-PN (36% vs 20%, p=0.051), however urological complications were similar (11% vs 8%). Mean eGFR decrease was 30% for CC-PN vs 6% for UN-PN p<0.0001). Similarly, in the UCPN cohort, more patients maintained pre-operative eGFR (22% vs 64%, p<0.0001) and fewer patients had new-onset CKD stage 3 (33% vs 6%, p<0.001). Trifecta outcomes were more common in the UC-PN cohort (20% vs 69%, p<0.0001). On univariate analysis baseline eGFR, WIT and UN-PN were predictors for achieving Trifecta. On multivariate analysis, UN-PN predicted for Trifecta. Main limitation is retrospective analysis and small number of patients. CONCLUSIONS: In the solitary kidney setting, unclamped PN conferred superior functional and Trifecta outcomes compared to clamped PN. ==fine abstract==