Alternative Method of Transient Vascular Occlusion FIG. 2. The Hem-o-lok clip was applied to the proximal portion of the vessel loop pulling the distal portion. with a 5 mm safety margin using curved laparoscopic scissors. Electrocautery was not used during resection of the tumor. The collecting system defect was reconstructed with 3-0 Vicryl, if necessary. The renal parenchyma was re- constructed with interrupted sutures with the use of the extracorporeal sliding knot technique using 2-0 Vicryl. When the vascular occlusion was no longer needed, the ves- sel loop was simply cut. This release of the tension allowed renal blood flow to resume. When the hemostasis was deemed to be adequate, the cellulose mesh (SurgicelⓇ, Ethicon Inc., USA) and fibrin sealant (TissucolⓇ, Baxter, AG, Austria) were applied on the sutured region. The Gerota’s fascia was also closed with interrupted sutures us- ing 2-0 Vicryl. The specimen was entrapped in an endo- scopic entrapment bag and extracted intact at the end of the surgery.  RESULTS All 15 LPNs were successfully performed without con- version to open surgery. The mean operative time was 177 minutes (range, 104-283 minutes) and the mean warm is- chemia time was 26.1 minutes (range, 18-34 minutes). The mean estimated blood loss was 190.6 ml (range, 50-400 ml) and 1 patient was given an intraoperative blood transfu- sion. The mean duration of postoperative hospitalization was 7.4 days (range, 5-9 days). 　The mean baseline serum creatinine level and glomer- ular filtration rate (GFR) were 0.87 mg/dl (range, 0.63-1.3 mg/dl) and 85.58 ml/min (range, 59.81-116.98 ml/min), respectively. The serum creatinine level was checked at 1, 3, and 5 days after the operation and the GFR was calcu- lated. The mean (range) serum creatinine level and GFR, respectively, were 1.04 mg/dl (0.67-2.1) and 73.01 ml/min (31.75-96.56) at day 1, 0.95 mg/dl (0.56-1.41) and 81.5 ml/min (48.52-122.56) at day 3, and 0.9 mg/dl (0.62-1.31) and 83.58 ml/min (51.8-111.21) at day 5. The serum crea- tinine level increased at postoperative day 1 and then grad- ually decreased (Table 2). TABLE 2. Operative data Operation time (minutes) Warm ischemic time (minutes) Estimated blood loss (ml) Hospital stay (days) Preoperative serum creatinine level (mg/dl) Postoperative serum creatinine level (mg/dl) 　1st day after surgery 　3rd day after surgery 　5th day after surgery Preoperative GFR (ml/min) Postoperative GFR (ml/min) 　1st day after surgery 　3rd day after surgery 　5th day after surgery 545 Mean value (ranges) 177 (104-283) 26.1 (18-34) 190.6 (50-400) 7.4 (5-9) 0.87 (0.63-1.3) 1.04 (0.67-2.1) 0.95 (0.56-1.41) 0.9 (0.62-1.31) 85.58 (59.81-116.98) 73.01 (31.75-96.56) 81.5 (48.52-122.56) 83.58 (51.8-111.21) 　The mean tumor size was 2.5 cm (range, 1.5-3.1 cm). Renal cell carcinoma was seen in 8 cases, and all of them were the clear cell type. There was no case of a positive sur- gical margin. Angiomyolipoma was seen in 7 cases. 　All hemostatic procedures were successful in the repair of the vascular and collecting system on the resection bed and renorrhaphy. In the case of intraoperative transfusion, neglect of an accessory vessel caused excessive bleeding, but it was controlled by prompt parenchymal recons- truction without open conversion. There was no uncontrol- lable intraoperative bleeding and no case of postoperative complications, such as bleeding, urinoma, or hydrone- phrosis.  DISCUSSION At first, partial nephrectomy was applied to renal cell carci- noma of a solitary kidney or for bilateral renal cell carcinoma. The range of indicants has recently been en- larged, however, such that partial nephrectomy has been used for patients having normal contralateral kidneys [7-10]. Regarding localized renal cell carcinoma measuring 4 cm and less, partial nephrectomy does not differ from rad- ical nephrectomy in terms of the long-term survival rate; besides, it has been regarded as being useful for preserving renal function [11,12]. In the case of partial nephrectomy, laparoscopic surgery is more effective for patient recovery, to relieve pain, and to shorten the hospitalization time in comparison with laparotomy; moreover, it is less invasive [13-15]. Accordingly, LPN has become the standard treat- ment for small sized renal cell carcinoma. 　The goal of a partial nephrectomy is complete local ex- cision of the tumor with minimal complications and opti- mal preservation of the renal remnant. Transient vascular occlusion is a crucial process to facilitate tumor excision with a relatively bloodless surgical field to achieve the goals of a partial nephrectomy. In laparoscopic surgery, a blood- Korean J Urol 2011;52:543-547