RecruitingProcedureClAmpless, Sutureless PartIAl Nephrectomy for Renal MassesDuring partial nephrectomy surgery, efforts at minimizing ischemia while maximizing renal parenchymal volume are desirable to preserve renal function1,2. Not only clamping of the hilum but the renorrhaphy portion of the procedure also can have a significant negative impact on renal function3-5. It is possible to perform this procedure without clamping the hilum and also without formal renorrhaphy. However robust prospective formal evaluation of safety, risks, and potential benefits and whether or not the technique can be employed in a generalized fashion has not been studied. Demonstration of safety and generalizability may open a whole new avenue of approaching nephron sparing and renal function sparing kidney surgery and decrease potential risks for long term kidney disease in patients with renal masses. This study will investigate the safety, efficacy, and generalizability of the use of clampless, sutureless partial nephrectomy in the treatment of renal cell carcinoma.