Clamped or Unclamped Surgery in Treating Patients With Kidney Cancer

• Change from baseline in renal function as measured by eGFR [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]
  Measured by eGFR, MAG-3 Nuclear Renal Scan, and serum creatinine. The two arms will be compared using regression methods that will account for repeated measures and the pre-randomization stratification.
  
  

• Estimated blood loss during surgery [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  
• Rate of blood transfusion during and after surgery [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  
• Number of patients with positive surgical margins [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  
• Number of patients with complications during surgery and at 90 days post surgery [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  
• Number of patients with adverse events [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  
• Intra-renal blood flow measurements [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]
  
• Resistive index measurements [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]
  

PRIMARY OBJECTIVES: I. To compare the changes in renal function (post-operative compared to pre-operative) in patients undergoing unclamped partial nephrectomy with or without controlled hypotension (Arm A) vs. those undergoing partial nephrectomy with hilar clamping (Arm B), as measured by change in estimated glomerular filtration rate (eGFR). SECONDARY OBJECTIVES: I. To compare the changes in renal function (post-operative compared to pre-operative) in patients undergoing unclamped partial nephrectomy with or without controlled hypotension (Arm A) vs. those undergoing partial nephrectomy with hilar clamping (Arm B), as measured by change in MAG3 (% of function attributed to affected kidney) and change in serum creatinine. II. To evaluate the safety of the unclamped procedure by estimating the differences in complication rates in patients undergoing unclamped partial nephrectomy with or without controlled hypotension (Arm A) vs. patients undergoing partial nephrectomy with hilar clamping (Arm B) in terms of intra-operative complications and post-operative complications. III. To evaluate the surgical effectiveness of the unclamped procedure by estimating the differences between patients undergoing unclamped partial nephrectomy with or without controlled hypotension (Arm A) vs. patients undergoing partial nephrectomy with hilar clamping (Arm B) in terms of surgical margin status, estimated blood loss, and transfusion rate (intraoperative and post-operative). TERTIARY OBJECTIVES: I. To record and compare the intrarenal blood flow and resistive index measurements in order to determine if a relationship exists between intraoperative findings and postoperative renal function. II. To quantify the amount of acute kidney injury (AKI) and compare the differences between patients undergoing unclamped partial nephrectomy with or without controlled hypotension (Arm A) vs. patients undergoing partial nephrectomy with hilar clamping (Arm B) as measured by urinary and serum biomarkers. III. To compare the effects of the unclamped procedure (Arm A) to the clamped procedure (Arm B) in patients with baseline eGFR < 60, and in patients with age >= 75 (exploratory subset analyses). OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM A: Patients undergo unclamped partial nephrectomy. Some patients may undergo unclamped partial nephrectomy with controlled hypotension. ARM B: Patients undergo clamped partial nephrectomy. After completion of study treatment, patients are followed up at 1 week and then at 1, 3, 6, and 12 months.