Comparison of parenchymal volume loss assessed by three-dimensional computed tomography volumetry and renal functional recovery between conventional and robot-assisted laparoscopic partial nephrectomy.

OBJECTIVES We retrospectively investigated if robot-assisted laparoscopic partial nephrectomy (RAPN) contributes to a decrease in resected parenchymal volume (RPV), an increase in postoperative parenchymal volume (PPV), and an improvement of postoperative renal function when compared with conventional laparoscopic partial nephrectomy (LPN) using a three-dimensional image analysis system. METHODS Patients who underwent LPN (n = 37) and RAPN (n = 66) from November 2013 to November 2018 were included in this study. All patients had a tumor diameter of 4 cm or less. Patients with an anatomical or functional single kidney were excluded. RPV and PPV were measured using SYNAPSE VINCENT®. The surgical outcomes were compared between the two groups. RESULTS Warm ischemic time in the RAPN group was significantly shorter than that in the LPN group (p < 0.001). The ratio of RPV to tumor volume (RPV/TV) in the RAPN group was significantly lower than that in the LPN group (p = 0.016). PPV in the RAPN group was significantly higher than that in the LPN group (p = 0.049). The decreased estimated glomerular filtration rate in the RAPN group was significantly lower than that in the LPN group on days 1, 7, 30, 90, and 180 after surgery. CONCLUSIONS Postoperative renal function in the RAPN group was significantly better than that in the LPN group in both the short and long term. In addition to a short warm ischemia time, the decreased RPV/TV and increased PPV may have contributed to the improvement of postoperative renal function.