Laparoscopic partial nephrectomy for hilar tumors

PURPOSE: Partial nephrectomy for hilar tumors represents a technical challenge not only for laparoscopic, but also for open surgeons. We report the technical feasibility and perioperative outcomes of laparoscopic partial nephrectomy (LPN) for hilar tumors. MATERIALS AND METHODS: Between January 2001 and September 2004, 25 of 362 patients (6.9%) undergoing LPN for tumor, as performed by a single surgeon, had a hilar tumor. We defined hilar tumor as a tumor located in the renal hilum that was demonstrated to be in actual physical contact with the renal artery and/or renal vein on preoperative 3-dimensional computerized tomography. En bloc hilar clamping with cold excision of the tumor, including its delicate mobilization from the renal vessels, followed by sutured renal reconstruction was performed routinely. RESULTS: Laparoscopic surgery was successful in all cases without any open conversions or operative re-interventions. Mean tumor size was 3.7 cm (range 1 to 10.3), 4 patients (16%) had a solitary kidney and the indication for LPN was imperative in 10 patients (40%). Pelvicaliceal repair was performed in 22 patients (88%), mean warm ischemia time was 36.4 minutes (range 27 to 48), mean blood loss was 231 cc (range 50 to 900), mean total operative time was 3.6 hours (range 2 to 5) and mean hospital stay was 3.5 days (range 1.5 to 6.7). Histopathology confirmed renal cell carcinoma in 17 patients (68%), of whom all had negative margins. In 2002 or earlier hemorrhagic complications occurred in 3 patients (12%). No kidney was lost for technical reasons. CONCLUSIONS: LPN can be performed in select patients with a hilar tumor. The technical feasibility reported further extends the scope of LPN. To our knowledge the initial experience in the literature is reported.     

Laparoscopic partial nephrectomy in solitary kidney

PURPOSE: We report our experience with LPN for tumor in a solitary kidney. MATERIALS AND METHODS: Of 430 patients undergoing LPN since February 1999 at our institution 22 (5%) underwent LPN for tumor in a solitary kidney, as performed by a single surgeon. The laparoscopic technique that we used duplicated open principles, including hilar clamping, cold cut tumor excision and sutured renal reconstruction. RESULTS: Mean tumor size was 3.6 cm (range 1.4 to 8.3, median 3 cm), median blood loss was 200 cc (range 50 to 500), warm ischemia time was 29 minutes (range 14 to 55), total operative time was 3.3 hours (range 2.2 to 4.5) and hospital stay was 2.8 days (range 1.3 to 12). Two cases (9%) were electively converted to open surgery. Pathological findings confirmed renal cell carcinoma in 16 patients (73%) with negative surgical margins in all those with LPN. Major complications occurred in 3 patients (15%) and minor complications developed in 7 (32%). Median preoperative and postoperative serum creatinine (1.2 and 1.5 mg/dl) and estimated glomerular filtration rate (67.5 and 50 ml per minute per 1.73 m2) reflected a change of 33% and 27%, respectively, which appeared proportionate to the median amount of kidney parenchyma excised (23%). One patient (4.5%) required temporary hemodialysis. At a median followup of 2.5 years (range 0.5 to 4.5) cancer specific and overall survival was 100% and 91%, respectively. No patient with LPN had local or port site recurrence, or metastatic disease. CONCLUSIONS: LPN can be performed efficaciously and safely in select patients with tumor in a solitary kidney. To our knowledge we present the largest series in the literature. Advanced laparoscopic experience and expertise are necessary in this high risk population.     

'Zero ischaemia', sutureless laparoscopic partial nephrectomy for renal tumours with a low nephrometry score

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Ischaemic injury produced by hilar clamping during partial nephrectomy is the main determinant of renal function loss. The exact measurement of ipsilateral renal function loss can be underestimated by serum creatinine levels and estimated GFR. Few reports of unclamped laparoscopic partial nephrectomy (LPN) are available in the literature, although this technique shows promising results. The present study includes a series of patients with the longest follow‐up of LPN without hilar clamping and without parenchymal reconstruction. Excellent cancer control and optimum renal functional preservation suggest that this technique could be performed in selected patients, i.e. those with small and peripheral tumours (also classified as low nephrometry score tumours).

OBJECTIVE

• ? To describe the technique and report the results of ‘zero ischaemia’, sutureless laparoscopic partial nephrectomy (LPN) for renal tumours with a low nephrometry score.

PATIENTS AND METHODS

• ? Between August 2003 and January 2010, data from 101 consecutive patients who underwent ‘zero ischaemia’, sutureless LPN were collected in a prospectively maintained database.
• ? Inclusion criteria were tumour size ≤4 cm, predominant exophytic growth and intraparenchymal depth ≤1.5 cm, with a minimum distance of 5 mm from the urinary collecting system.
• ? Hilar vessels were not isolated, tumour dissection was performed with 10‐mm LigaSure^TM (Covidien, Boulder, CO, USA) and haemostasis was performed with coagulation and biological haemostatic agents without reconstructing the renal parenchyma.
• ? Clinical, perioperative and follow‐up data were collected prospectively, and modifications of functional outcome variables were analysed using the paired Wilcoxon test.

RESULTS

• ? The median (range) tumour size was 2.4 (1.5–4) cm, and the median (range) intraparenchymal depth was 0.7 (0.4–1.4) cm.
• ? Hilar clamping was not necessary in any patient, and suture was performed in four patients to ensure complete haemostasis. The median (range) operation duration was 60 (45–160) min, and median (range) intraoperative blood loss was 100 (20–240) mL.
• ? Postoperative complications included fever (n= 4), low urinary output (n= 3) and haematoma, which was treated conservatively (n= 2). The median (range) hospital stay was 3 (2–5) days. The pathologist reported 30 benign tumours and renal cell carcinoma in 71 cases (pT1a in 69 patients, and pT1b in two patients).
• ? At a median follow‐up of 57 months, one patient underwent radical nephrectomy for ipsilateral recurrence. The 1‐year median (range) decrease of split renal function at renal scintigraphy was 1 (0–5) %.

CONCLUSIONS

• ? Zero ischaemia LPN is a reasonable approach to treating small and peripheral tumours, and a sutureless procedure is feasible in most cases.
• ? This technique has a low complication rate and provides excellent functional outcome without impairing oncological results.

     

Laparoscopic partial nephrectomy for multiple tumours: feasibility and analysis of peri-operative outcomes

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Laparoscopic nephron‐sparing procedures have been increasingly utilized. However, in the presence of multiple tumours the procedure choice is usually shifted to radical nephrectomy. In view of favourable perioperative outcomes, the benefits of minimally‐invasive, nephron‐sparing surgery in experienced hands could be safely extended to patients presenting with multiple ipsilateral renal masses.

OBJECTIVE

• ? To describe our experience with laparoscopic partial nephrectomy (LPN) for multiple kidney tumours and compare the outcomes with LPN performed for single masses.

PATIENTS AND METHODS

• ? Retrospective analysis of medical records of patients undergoing LPN at our institution between 2005 and 2009 was performed.
• ? The cohort was divided in two groups based on tumour focality: group 1, LPN for a single tumour (n= 99) and group 2, LPN for multiple ipsilateral tumours (n= 12).
• ? The groups were compared with regards to demographic and peri‐operative variables.

RESULTS

• ? Demographic variables were not different between the groups. Median dominant tumour size was 3.1 cm (interquartile range [IQR] 2.4–4.0) and 4.0 cm (2.3–5.9) in groups 1 and 2, respectively.
• ? Median secondary tumour size in group 2 was 1.0 cm (1.0–1.8).
• ? Operative times were longer in group 2 compared with group 1 (220 vs 160 min, P= 0.009).
• ? Warm ischaemia times (WIT) (23 vs 22 min) and estimated blood loss (EBL) (100 vs 85 mL) were similar.

CONCLUSIONS

• ? LPN is a viable option for the treatment of multiple ipsilateral renal tumours.
• ? Peri‐operative outcomes are similar to standard LPN with the exception of longer operative time.
• ? In experienced hands, the advantages of minimally invasive surgery may be extended to select patients with ipsilateral multifocal renal tumours.

     

Laparoscopic partial nephrectomy for cystic masses

PURPOSE: Although laparoscopic partial nephrectomy (LPN) has emerged as an effective treatment option in select patients with a solid renal tumor, scant data are available on cystic renal tumors. We report our experience with LPN in 50 patients with a cystic renal lesion. MATERIALS AND METHODS: Of 284 patients undergoing LPN at our institution since August 1999 preoperative computerized tomography identified a suspicious cystic lesion in 50 (17.6%) (group 1). Data were retrospectively compared with those on 50 matched, consecutive patients undergoing LPN for a solid renal mass (group 2). All patients with Bosniak II/IIF cysts were advised to undergo watchful waiting. Surgery was offered if the cyst changed in character or if that was the patient preference. RESULTS: Median tumor size was 3 cm in group 1 and 2.6 cm in group 2 (p = 0.07). Groups 1 and 2 were comparable in regard to perioperative parameters. In patients with Bosniak II (9), IIF (4), III (12) and IV (21) cysts final histopathology revealed renal cell carcinoma in 22%, 25%, 50% and 90%, respectively. All 100 patients had a negative surgical margin. No patient in group 1 had intraoperative puncture/spillage of the cystic tumor. In group 1 during a mean followup of 14 months (range 1 month to 3 years) 1 patient had retroperitoneal recurrence at 1 year despite negative surgical margins during initial LPN. CONCLUSIONS: Surgical outcomes of LPN for suspicious cystic masses are similar to those of LPN for solid tumors. However, extreme caution and refined laparoscopic technique must be exercised to avoid cyst rupture and local spillage.     

Laparoscopic partial nephrectomy: 3-year followup

PURPOSE: LPN is a viable alternative to open partial nephrectomy for select small renal tumors. However, published intermediate term oncological data are sparse. We present our experience with LPN for tumor in 100 patients with a minimum followup of 3 years. MATERIALS AND METHODS: Of the 480 LPNs performed at our institution a minimum followup of 3 years is available in 100 patients since 1999. Overall and cancer specific survival data were obtained from patient charts, radiographic reports and direct telephone calls to patient families. RESULTS: All 100 cases were completed laparoscopically without open conversion. Mean tumor size was 3.1 cm and mean warm ischemia was 27 minutes. Final histopathology revealed renal cell carcinoma in 68 patients, including 1 with positive surgical margins. A second patient with oncocytoma had a positive surgical margin. At a median followup of 42 months (mean 42.6, range 24.3 to 62.5) no patient had evidence of local or port site recurrence. Two patients with renal cell carcinoma had a contralateral renal mass. Overall survival was 86% and cancer specific survival was 100%. Mean preoperative and postoperative serum creatinine was 1.1 and 1.3 mg/dl, respectively. Two patients with preoperative chronic renal insufficiency were undergoing hemodialysis. CONCLUSIONS: At 3-year followup LPN provides oncological outcomes comparable to those in contemporary open partial nephrectomy series.     

Laparoscopic partial nephrectomy: comparison of transperitoneal and retroperitoneal approaches

PURPOSE: Laparoscopic partial nephrectomy has become an effective alternative for small renal tumors. Previous reports include transperitoneal and retroperitoneal approaches but to our knowledge the indications for when to apply the techniques have not been defined. We report our experience with comparing the 2 techniques. MATERIALS AND METHODS: A retrospective review of 51 laparoscopic partial nephrectomies was performed. Patients were analyzed based on the surgical approach, operative parameters and postoperative recovery. The 2 approaches used similar operative techniques to control parenchymal bleeding and collecting system entry. RESULTS: There were 32 retroperitoneal and 19 transperitoneal partial nephrectomies. Mean operative time (3.5 vs 5.4 hours, p = 0.000001) and blood loss (192 vs 403 cc, p = 0.002) was significantly less for the retroperitoneal approach. Renal vessel clamping was performed in 81% of retroperitoneal and 63% of transperitoneal operations. Warm ischemia time was not significantly different between the groups. Patients undergoing the retroperitoneal approach had a statistically significant decrease in time to tolerating a regular diet (1.2 vs 1.7 days, p = 0.02), catheter removal (1.4 vs 2.5 days, p = 0.004) and discharge home (2.3 vs 3.6 days, p = 0.0008). CONCLUSIONS: Based on tumor location as the selection criteria the retroperitoneal approach was associated with shorter operative time, less blood loss, more rapid return of bowel function and shorter hospitalization compared with those in patients selected for the transperitoneal technique. Based on our experience we believe that the decision on the approach should be based on the tumor location on the kidney surface. For polar or posterolateral masses the retroperitoneal approach is preferred. The transperitoneal approach is best suited to anterior and medial lesions.     

Laparoscopic partial nephrectomy of solid renal masses without hilar clamping using a monopolar radio frequency device

PURPOSE: Partial nephrectomy is currently recommended for most amenable solid renal tumors, especially if they are exophytic and less than 4 cm. We reviewed our initial experience with laparoscopic partial nephrectomy for solid renal masses without clamping the renal vasculature using a monopolar device that uses radio frequency energy with low volume saline irrigation for simultaneous blunt dissection, hemostatic sealing and coagulation of the renal parenchyma (TissueLink, TissueLink Medical, Inc., Dover, New Hampshire). MATERIALS AND METHODS: From September 2002 to April 2003, 10 patients underwent transperitoneal laparoscopic partial nephrectomy, including 9 with solid renal masses and 1 with a complex cyst. In all cases the renal hilum was dissected and the renal vessels were isolated but none had renal vascular clamping. The TissueLink DS dissecting sealer or Floating Ball (TissueLink Medical, Inc.) was used to dissect the tumor free bluntly, while simultaneously sealing and coagulating bleeders. RESULTS: Mean patient age was 54.6 years (range 42 to 72). Mean American Society of Anesthesiologists score was 2.3 (range 2 to 4). Mean tumor size was 3.9 cm (range 2.1 to 8). The mass had a peripheral location in 7 cases and a central location in 3. Mean operative time was 232 minutes (range 144 to 280) and mean blood loss was 352 ml (range 20 to 1000). One patient received blood transfusion and all tumor margins were negative. Mean hospital stay was 1.7 days (range 1 to 5) and pain medication use was minimal. One patient had a brief period of urine leakage from the lower pole calix, which was managed successfully by ureteral stenting and Foley catheter drainage of the bladder. CONCLUSIONS: Laparoscopic partial nephrectomy can be performed without renal vascular clamping. TissueLink technology allows complete tumor resection and provides adequate parenchymal hemostasis of the tumor bed. Its scant tissue charring production does not interfere with the pathological assessment of the tumor margin status.     

腹腔镜手术治疗肾破裂出血

目的 探讨肾破裂出血行腹腔镜手术的可行性.方法 本组2例均为左肾破裂出血,1例出血后7 d手术,1例出血后当天手术,均行后腹腔镜肾切除术.结果 2例手术均成功,手术时间100～120 min,出血量200～300 mL.术后恢复好,无并发症.结论 应用腹腔镜治疗肾破裂出血是可行的.     

Laparoscopic partial nephrectomy: beyond the straightforward T1a

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Complex tumour features (e.g. size, hilar location, multifocality) are generally considered contraindicative for LPN and only a handful of studies reporting encouraging outcomes with more complex tumours. Herein we suggest that in experience hands the benefits of minimally‐invasive surgery may be safely extended to patients with more complex renal masses.

OBJECTIVE

• ? To report on our experience in extending the indications for LPN beyond the single, T1a renal mass assessing the perioperative outcomes in a comparative fashion.

PATIENTS AND METHODS

• ? Retrospective review of consecutive patients undergoing LPN for a renal mass in an academic centre between 2005–2010.
• ? 150 patients were divided into two groups based on tumours characteristics: straightforward T1a (group 1: single, <4 cm, n = 84) and complex (group 2: multiple and/or hilar and/or ≥4 cm, n = 66).
• ? Comparison of demographic, clinical, radiographic and perioperative outcomes (operative times, blood loss, warm ischemia times, intra‐ and postoperative complications).

RESULTS

• ? In group 2, 19 tumours were hilar, 15 were multifocal and 44 measured ≥4 cm; 2 of these criteria were present in 7, and all three in 3 cases.
• ? Warm ischemia times and blood loss were comparable (medians of 21 vs 20 min, and 100 vs 100 mL).
• ? Operative times were longer in group 2 (190 vs 140min, P < 0.001).
• ? Complications occurred in 11.9% and 12.1% of patients in group 1 and 2, with Clavien grade 3 events in 8.3 and 10.9%, respectively (P = 1.00 and P = 0.547).
• ? There were 4 conversions to laparoscopic radical nephrectomy (1 in group 1, 3 in group 2).

CONCLUSION

• ? With adequate laparoscopic expertise, the indications for LPN can be safely extended beyond the single, small, peripheral T1a renal mass. In this series, more complex masses were effectively treated with LPN combining the advantages of minimally‐invasive surgery to those of nephron‐sparing approach.

     

Laparoscopic partial nephrectomy in cold ischemia: renal artery perfusion

PURPOSE: Laparoscopic partial nephrectomy represents a feasible option for patients with small renal masses. We describe our initial experience with laparoscopic partial nephrectomy in cold ischemia achieved by renal artery perfusion. MATERIALS AND METHODS: From November 2001 to March 2003 laparoscopic partial nephrectomy in cold ischemia was performed in 15 patients with renal cell carcinoma. Cold ischemia was achieved by continuous perfusion of Ringers lactate at 4C through the renal artery, which was clamped. Tumor excision was performed in a bloodless field with biopsy taken from the tumor bed. The collecting system was repaired if needed. Renal reconstruction was performed by suturing over hemostatic bolsters. RESULTS: All procedures were successfully completed laparoscopically by our new technique. Mean operative time was 185 minutes (range 135 to 220). Mean ischemia time was 40 minutes (range 27 to 101). Estimated mean intraoperative blood loss was 160 ml (range 30 to 650). Entry to the collecting system in 6 patients was repaired intraoperatively. Additional vascular repair was done in 2 patients. There were no significant postoperative complications. Postoperative followup in 8 patients showed that the renal parenchyma was not damaged by the ischemic period. CONCLUSIONS: Our initial experience of incorporating cold ischemia via arterial perfusion into laparoscopic partial nephrectomy shows the feasibility and safety of the technique. We believe that this approach has the potential to make laparoscopic partial nephrectomy for renal cell carcinoma safe and reliable.     

Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome

PURPOSE: Laparoscopic partial nephrectomy (LPN) has emerged as a viable alternative to open surgery for renal tumors less than 4 cm. We present oncological followup of patients treated with laparoscopic nephron sparing surgery at our institution. MATERIALS AND METHODS: Between September 1996 and December 2001, 48 patients who underwent LPN for clinically localized tumors were found to have pathologically proven renal cell carcinoma. Medical and operative records were reviewed for clinical characteristics, pathological findings and followup information. RESULTS: Mean patient age was 59.7 years (range 32 to 81) and mean followup was 37.7 months (range 22 to 84). Mean tumor size was 2.4 cm (range 1.0 to 4.0). Final pathological stage was pT1 in 42 patients (87.5%) and pT3a in 6 (12.5%). Histology revealed clear cell in 32 patients (66.7%), papillary in 10 (20.8%), chromophobe in 3 (6.3%), collecting duct in 1 (2.1%) and unclassified in 2 (4.2%). Intraoperative frozen section biopsies revealed negative margins in all cases. Final surgical margins were positive in 1 patient (2.1%). Followup evaluation consisting of physical examination and yearly cross-sectional imaging, which revealed no recurrences in 46 of 48 patients (95.8%). One patient with von Hippel-Lindau disease was found to have local recurrence 18 months after LPN and observation was elected. The second patient had recurrence in the same kidney away from the original tumor site approximately 4 years later. CONCLUSIONS: LPN is an effective treatment modality for clinically localized renal cell carcinoma. Oncological outcomes at a mean followup of 3 years are promising, although the durability of oncological outcomes must be determined.     

后腹腔镜上半肾切除术治疗重复肾畸形的初步研究

目的：探讨后腹腔镜上半肾切除术治疗重复肾畸形的方法和疗效。方法：2006年1月～2011年4月采用后腹腔镜上半肾切除术治疗重复肾畸形患者6例。结果：6例患者手术均获得成功。手术时间为110～280min,平均（172．6±31．2）min;术中出血量80~460ml,平均（165．8士47．5）ml,其中1例术中输血200ml;术后住院时间5～8d,平均（7．6±2．1）d;术中、术后未发生严重并发症。术后随访2～54个月,平均（20．5±4．5）个月,B超、IVU和（或）磁共振尿路成像显示重复。肾切除术后患者下半肾功能均正常。结论：后腹腔镜手术治疗重复’肾畸形创伤小,并发症少,恢复快,近期疗效安全、可靠,是重复肾双输尿管畸形可供选择的一种微创治疗方法,具有临床推广价值。     

Robotic-assisted laparoscopic partial nephrectomy: surgical technique and clinical outcomes at 1 year

OBJECTIVE

To report our surgical technique of robotic‐assisted laparoscopic partial nephrectomy (RLPN) for renal tumours of <7 cm and present their clinical outcomes, as minimally invasive PN is an increasingly viable option for small renal tumours.

PATIENTS AND METHODS

From July 2005 to December 2006, 20 consecutive patients (mean age 58.2 years, sd 7.9) had RLPN and a follow‐up of ≥1 year, all surgery being undertaken by one surgeon. All cases were elective except in one patient with a solitary kidney. We used the three‐arm da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA, USA) in a four‐port, transperitoneal approach. Transient vascular occlusion was applied in all cases using a tourniquet technique. The tumour was excised with a 5‐mm margin using cold‐cut scissors, and the margins were assessed by frozen sections. The specimen was placed in an impervious bag for subsequent removal via the camera port. Under direct vision, we repaired all pelvicalyceal system entries with absorbable sutures. After the entire tumour bed surface was lined with Floseal^TM (Baxter Healthcare, Deerfield, IL, ISA) the capsule/parenchyma was closed with running suture, reinforced by haemostatic clips.

RESULTS

The mean (sd ) operative and warm ischaemia times were 82.7 (17.0) and 21.7 (2.4) min, respectively, and the mean estimated blood loss was 189 (32) mL. There were no intraoperative complications or conversion to open surgery. There was also no bleeding after surgery, perinephric haematoma or urinary leakage. The mean (sd ) tumour size was 30.2 (2.4) mm, while margins were negative in all cases of malignancy. At the 1‐year follow‐up there was no local recurrence, renal functional deterioration or late surgical complications.

CONCLUSIONS

Our RLPN technique is a safe and feasible option for small renal tumours. Reproducible technique and good team co‐ordination are pivotal for obtaining good oncological and surgical outcomes.     

Laparoscopic partial nephrectomy for renal tumor: single center experience comparing clamping and no clamping techniques of the renal vasculature

PURPOSE: We performed a nonrandomized retrospective comparison of 2 techniques for laparoscopic partial nephrectomy, that is without and with clamping the renal vessels. MATERIALS AND METHODS: Between December 1997 and February 2002, 28 consecutive patients underwent transperitoneal laparoscopic partial nephrectomy for renal tumor. In group 1 (12 patients) partial nephrectomy was performed with ultrasonic shears and bipolar cautery without clamping the renal vessels, while in group 2 (16 patients) the renal pedicle was clamped before tumor excision. In group 2 patients intracorporeal kidney cooling was achieved by a ureteral catheter connected to 4C solution. Intracorporeal freehand suturing techniques were used to close the collecting system when opened and approximate the renal parenchyma. RESULTS: All procedures were successfully completed laparoscopically. Mean renal ischemia time +/- SD was 27.3 +/- 7 minutes (range 15 to 47) in group 2 patients. Mean laparoscopic operating time was 179.1 +/- 86 minutes (range 90 to 390) in group 1 compared with 121.5 +/- 37 minutes (range 60 to 210) in group 2 (p = 0.004). Mean intraoperative blood loss was significantly higher in group 1 than in group 2 (708.3 +/- 569 versus 270.3 +/- 281 ml., p = 0.014). Three patients in group 1 and 2 in group 2 required blood transfusions. Immediately postoperatively mean creatinine was 1.26 +/- 0.36 and 1.45 +/- 0.61 mg./dl. in groups 1 and 2, respectively (p = 0.075). Surgical margins were negative in all specimens. Pathological examination revealed renal cell cancer in 18 cases (stages pT1 in 17 and pT3a in 1), oncocytoma in 4, angiomyolipoma in 5 and renal adenoma in 1. CONCLUSIONS: Laparoscopic partial nephrectomy represents a feasible option for patients with small renal masses. Clamping the renal vessels during tumor resection and suturing the kidney mimics the open technique and seems to be associated with less blood loss and shorter laparoscopic operative time.