Improved perioperative outcomes by early unclamping prior to renorrhaphy compared with conventional clamping during robot-assisted partial nephrectomy: a propensity score matching analysis

The objective of this study was to evaluate the impact of the early unclamping (EU) technique on perioperative outcomes in patients who underwent robot-assisted partial nephrectomy (RAPN). This study included 96 patients with small renal masses who underwent RAPN performed by a single surgeon using the da Vinci Xi between April 2016 and September 2018. EU and conventional clamping (CC) procedures were defined as those removing the renal artery clamp before and after renorrhaphy, respectively. In this series, contrast-enhanced computed tomography was performed 3–5 days after RAPN to examine the incidence of renal artery pseudoaneurysm (RAP). After adjusting patient variables by 1:1 propensity score matching, 45 patients were included in both the EU and CC groups, and no significant differences in major clinical characteristics were noted between these two groups. Although there was no significant difference in the proportion of patients achieving trifecta or the margin, ischemia and complications score between the two groups, the EU group was significantly superior to the CC group regarding the operative time, console time, warm ischemia time, impairment of renal function 1 day after RAPN, incidence of RAP and postoperative length of hospital stay. Furthermore, RAP occurred in seven patients in the entire cohort (13.3%) receiving CC, including two who required trans-arterial embolization due to severe macrohematuria, whereas RAP was completely prevented by the use of EU. The introduction of the EU technique to RAPN may improve perioperative outcomes, particularly by markedly reducing the risk of RAP even with renorrhaphy.