Renal functional reserve may be better in patients with clinical T1 renal cell carcinoma(RCC) undergoing laparoscopic partial nephrectomy with precise segmental renal artery clamping than those with complete renal arterial clamping.

Renal functional reserve (RFR) describes the capacity of the intact nephron mass to increase glomerular filtration rate(GFR) from baseline in response to stimuli (e.g., protein load).We hypothesized that renal functional reserve may be better in patients with clinical T1 renal cell carcinoma(RCC) undergoing laparoscopic partial(LPN) nephrectomy with precise segmental renal artery clamping than those with complete renal arterial clamping.

Inclusion Criteria:

• 1.Age ≥18 2.Estimated GFR >30 mL/min/1.73m2 3.Anticipated intraoperative warm ischemic time ≤30 min 4.Subjects who signed informed consent forms

Exclusion Criteria:

1. Allergy to iothalamate, shellfish or iodine
2. Use of metformin or amiodarone
3. intraoperative warm ischemic time >30 min
4. Inability to maintain a stable regimen of medications which affect GFR for > one week prior to participation (e.g. non-steroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers)
5. Use of medications which directly affect elimination of creatinine (e.g. cimetidine and trimethoprim)
6. Acute exacerbation of asthma or chronic obstructive pulmonary disease within 3 months requiring hospitalization or oral steroid therapy
7. Inadequate intravenous access
8. Severe anemia (Hct <21%)
9. Acute kidney injury (rise in creatinine to ≥1.5 times the previous baseline or by ≥ 0.3 mg/dL on most recent labs prior to enrollment)
10. History of contrast-induced nephropathy
11. Hyperthyroidism
12. Pheochromocytoma
13. Sickle cell disease
14. Urinary retention or incontinence
15. Status post organ transplant
16. Pregnancy or active breast feeding
17. Cognitive impairment with inability to give consent
18. Institutionalized status