There is increasing interest in preserving renal function when removing renal tumors. This is partly due to studies that link chronic kidney disease with cardiovascular events and overall survival. There is an approximate loss of 10% overall renal function after partial nephrectomy along with a loss of 15% of the volume in the operated kidney. Studies point to 3 factors leading to this loss in renal function after partial nephrectomy: 1) Poor preoperative renal function, 2) Ischemia time (clamping the renal blood vessels to decrease bleeding during surgery, and 3) Loss in renal volume from the surgery.