Evaluation of renal function after laparoscopic partial nephrectomy with renal scintigraphy using ^99mtechnetium-mercaptoacetyltriglycine

Aim: We evaluated the functions of an affected kidney after laparoscopic partial nephrectomy (LPN) using renal scintigraphy with ^99mtechnetium-mercaptoacetyltriglycine (^99mTc-MAG3). Methods: Split renal function of 10 patients who underwent LPN for renal tumors was assessed using renal scintigraphy with ^99mTc-MAG3 before surgery, and 1 week and 3 months post-surgery. Results: Median operating time was 196.5 min, median tumor diameter was 2.3 cm, mean blood loss was 64 mL and mean ischemic time was 38.5 min. Median change in serum creatinine level pre- to post-surgery was 0.15 mg/dL. Median contribution of the affected kidney to total renal function (calculated using ^99mTc-MAG3) was 50.0%, 41.7% and 36.1% before surgery, 1 week and 3 months after LPN, respectively. In one patient, the tumor was resected after cooling of the affected kidney with ice slush for 15 min, and the split renal function ratio remained as high as 50% at 3 months post-operatively despite a total ischemic time of 61 min. Conclusions: This paper evaluated renal function on the affected side before and after surgery by measuring split renal function with renal scintigraphy using ^99mTc-MAG3. Risk factors for renal dysfunction in the affected kidney after LPN include age over 70 years with more than 30 min warm ischemic time, re-clamping of the renal artery procedure, and a warm ischemic time greater than 60 min. We believe that renal cooling with slush ice prevents renal dysfunction of the affected kidney after LPN with longer warm ischemic times. However, an easier renal cooling technique should be sought for regular use of cooling procedures in LPN.