Robot-Assisted Laparoscopic Partial Nephrectomy Vs Conventional Laparoscopic Partial Nephrectomy: Functional and Surgical Outcomes of a Prospective Single Surgeon Randomized Study

Background:Laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN) are commonly used techniques for treating small renal masses. Regarding renal function (RF) preservation, no superiority of one technique over the other has yet been definitely demonstrated. Objective:To compare functional and surgical outcomes of LPN and RAPN. Patients and Methods:Between 2015 and 2019, we prospectively randomized 115 patients with cT1-T2 renal masses to LPN in total ischemia or RAPN in selective ischemia. Primary endpoint was RF preservation, assessed by renal scintigraphy (RS). RS assessments were performed preoperatively and at 6 months follow-up. Secondary endpoints included clinical, histopathologic, and surgical outcomes. Results:One hundred eight patients were included in the final analysis. Patient and tumor characteristics were comparable. No significant difference in RS values after 6 months was observed between both groups. Median (interquartile range) RF change after 6 months was -18.0% (-26.5 to -11.0) in LPN group and -20.0 (-33.2 to -12.0) in RAPN group (p = 0.3). Mean (standard deviation [SD]) warm ischemia time was 21.1 (6.1) minutes in LPN group and 19.6 (7.7) minutes in RAPN group (p = 0.2). No positive surgical margins (PSMs) occurred in the LPN group, whereas RAPN group had PSM in 4.9% (n = 3);p = 0.099. Renal volume loss after 6 months was 27.5% (22.7-45.7) in the LPN groupvs37.5 (13.7-54.2) in the RAPN group (p = 0.5). Mean operative times were lower in the LPN group (192.3 minutes [SD 44.5]vs230.2 minutes [SD 59.6],p = 0.001). More complications occurred in the LPN group (31%vs21%,p = 0.075). Transfusion rates were 15% for LPN and 11% for RAPN. Conclusions:In terms of preserving RF, LPN in total ischemia and RAPN in selective ischemia are comparable. In most patients, RF decrease of the affected kidney after PN seems to not exceed 25%, regardless of the surgical approach.