Possible Detrimental Effects of Clamping Main Versus Segmental Renal Arteries for the Achievement of Renal Global Ischemia During Robot-Assisted Partial Nephrectomy.

PURPOSE:To determine the impacts of clamping the main renal artery vs individually clamping presegmental or segmental arteries at the time of global renal ischemia on the surgical and functional outcomes of robot-assisted partial nephrectomy (RAPN). PATIENTS AND METHODS:Patients who underwent RAPN at our center from 2009 to September 2013 were assessed for details of intraoperative renal arterial anatomy. Cases were divided into two groups according to the type of global renal ischemia: Group 1 consisted of cases where one main renal artery (or hilum) was clamped; group 2 included cases where multiple arteries or multiple branches of arteries were individually clamped. Patient demographics, tumor characteristics, perioperative data, functional outcomes (as well as pathology findings) were assessed for both groups. Univariable and multivariable analyses were performed for identifying factors predicting early (at day 3) estimated glomerular filtration rate (eGFR) preservation postoperatively. RESULTS:Group 1 and group 2 included 468 and 111 patients, respectively. Estimated blood loss and warm ischemia time (WIT) were comparable between the two groups. A higher proportion of combined arterial and venous clamping was observed in group 1 (76.2% vs 52.3%; P=0.0001). On postoperative day 3, eGFR preservation was not significantly different between the two groups (P=0.87). On multivariable analysis, WIT and preoperative eGFR remained the only significant predictors of early eGFR preservation. The number of arterial vessels clamped during the procedure or simultaneous arterial/vein clamping were not predictors of early eGFR preservation. CONCLUSIONS:Perioperative outcomes of RAPN are not influenced by clamping the main renal artery compared with clamping multiple branches of the renal artery for achievement of global renal ischemia. WIT and baseline eGFR were confirmed to be significant predictors of postoperative renal function preservation after RAPN.