HAND ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY FOR PERIPHERAL AND CENTRAL LESIONS: A REVIEW OF 30 CONSECUTIVE CASES

0022-5347/04/1714-1443/0 THE JOURNAL OF UROLOGY® Copyright © 2004 by AMERICAN UROLOGICAL ASSOCIATION

Vol. 171, 1443–1446, April 2004 Printed in U.S.A.

DOI: 10.1097/01.ju.0000117962.54732.3e

HAND ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY FOR PERIPHERAL AND CENTRAL LESIONS: A REVIEW OF 30 CONSECUTIVE CASES JAMES A. BROWN,* SCOTT G. HUBOSKY, LEONARD G. GOMELLA†

AND

STEPHEN E. STRUP‡

From the Department of Urology, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania

ABSTRACT

Purpose: We reviewed our first 30 hand assisted laparoscopic partial nephrectomies and compared the results of 8 centrally located vs 22 peripherally located tumors. Materials and Methods: Tumors were classified by computerized tomography as central (less than 5 mm from the pelvicaliceal system or hilar vessels) or peripheral. The hand assisted technique consisted of mobilization and manual parenchymal compression without vascular occlusion or ureteral stent placement. Argon beam coagulation and a fibrin glue bandage were used for hemostasis. Results: Mean tumor size was 2.6 cm (range 1.0 to 4.7). Mean operative time was 199 and 271 minutes, and estimated blood loss was 240 and 894 ml for peripheral and central lesions, respectively. No case required open conversion. The final diagnoses were renal cell carcinoma in 21 patients, angiomyolipoma in 4, benign or hemorrhagic cyst in 3 and oncocytoma in 2. Initial positive margins were found in 5 of 30 specimens (16.7%) (1 central and 4 peripheral) and all final resection margins were negative. Four central (50%) and 2 peripheral (9.1%) tumor cases required transfusion. Drain creatinine was elevated in 6 patients (20%) postoperatively, of whom 3 had a central and 3 had a peripheral lesion. All responded to conservative management except 1 patient (3.3%) who required stent placement. Postoperative bleeding in a central tumor case required transfusion of 4 units. There were no short-term local recurrences and 1 patient had an asynchronous tumor. Conclusions: Hand assisted laparoscopic partial nephrectomy is safe with excellent immediate cancer control. Careful dissection and frozen section analysis are mandatory to ensure a negative tumor margin. Blood loss and transfusion rates were higher in patients with centrally located tumors and renal hilar vascular control should be considered for central lesions. KEY WORDS: kidney, carcinoma, renal cell; nephrectomy; laparoscopy

Partial nephrectomy (PN) has grown in popularity as a management strategy for small renal masses. In the 1990s several successful initial laparoscopic (L) PN series were reported1– 8 with renal hemorrhage identified as the major complication of LPN. Many techniques aimed at decreasing blood loss have been described, such as enhanced hemostasis, cable tie compression, hydro-jet dissection, high frequency bipolar electrical current, high frequency unipolar spray electrical current, ultrasound, microwave, electrosurgical snare electrodes and radio frequency coagulation assistance.1, 9 –16 Hand assisted (HA) LPN and LPN with occlusion of the renal hilum using a laparoscopic Satinsky clamp have also been described (table 1).17–19 Initial reports indicated a 3 to 4.5hour operative time with 270 to 460 ml estimated blood loss (EBL) and a transfusion rate of less than 10%. There were no margin positive specimens or recurrences and only isolated cases of urine leakage.17–19 Gill et al reported LPN in 4 solitary kidney cases for a median 3.2 cm tumor with a warm ischemia time of 17.4 minutes, operative time of 3.2 hours, and preoperative and postoperative serum creatine of 1.1 and 1.3 mg/dl, respectively. Different laparoscopic approaches to

PN have similar short-term outcomes and there is no differentiation based on lesion location. We retrospectively evaluated the first 30 HALPNs at 1 institution, comparing the outcomes of central vs peripheral lesions. MATERIALS AND METHODS

From April 2000 to March 2002, 30 sequential patients with solitary suspicious renal masses underwent HALPN at our institution. On computerized tomography (CT) mean tumor size was 2.6 cm (range 1 to 4.7). Tumor location was the left upper, left mid, left lower, right upper, right mid, right lower and right indeterminate pole in 2, 5, 8, 3, 5, 6 and 1 cases, respectively. CT was not available in the latter patient. In 8 cases (26.7%) the lesions were classified as central when the margin abutted or was within 5 mm of the pelvicaliceal system, or mid pole tumor was in close proximity (less than 5 mm) to the hilar vasculature. TECHNIQUE

Our procedure is similar to the technique of Wolf et al.17 A 7 cm supraumbilical midline incision was made extending into the umbilicus and a HA laparoscopy device such as the Lap Disc (Ethicon Endosurgical, Cincinnati, Ohio) was placed. The peritoneum was insufflated and a 12 mm port was placed lateral to the rectus muscle. The surgeon cephalad hand (left hand for the left kidney and right hand for the right kidney) was inserted and an additional 5 or 12 mm port was placed at the anterior axillary line. The colon was mobi-

Accepted for publication November 7, 2003. Study received institutional review board approval. * Current address: Section of Urology, Department of Surgery, Medical College of Georgia, Augusta, Georgia 30912. † Correspondence and requests for reprints: Department of Urology, Thomas Jefferson University, 1025 Walnut St., Philadelphia, Pennsylvania 19317 (telephone: 215-955-1702). ‡ Current address: Division of Urology, University of Kentucky Medical Center, Lexington, Kentucky 40536-0298. 1443

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HAND ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY TABLE 1. Comparative published series of LPN

Approach

Present Series

Wolf et al17

Transperitoneal HALPN

Transperitoneal HALPN

Periop parameters: No. pts 30 Mean tumor size (cm) 2.6 No. central tumors (%) 8 (27) EBL (cc) 415 OR time (mins) 218 Hospital stay (days) 4.0 No. complications: Open conversion 0 Persistent urine leakage 1 Intraop hemorrhage 2 Delayed hemorrhage 1 Transfusion (%) 6 (20) Re-intervention (%) 1 (3) Followup: No. asynchronous multifocal disease 1 Mean mos followup (range) 8.8 (4–15) There were no final positive margins or recurrent disease.

10 2.4 3 (30) 460 199 2.0 0 0 1 0 1 (10) 0 Not available 8

lized and Gerota’s fascia was entered laterally. The perinephric fat was cleared except for fat overlying the tumor and the examined kidney. A 5 mm port was placed in the upper midclavicular line to facilitate aspiration/irrigation during resection. The hilum was not dissected or clamped and in 3 cases intraoperative ultrasound was performed. The renal capsule was scored 5 mm from the tumor. Using hemostatic parenchymal hand compression PN was performed to include a 5 mm rim of normal tissue. Endoscopic scissors without cautery were used for resection. Hemostasis was achieved with argon beam coagulation, followed by placement of a bandage of gelatin sponge soaked with fibrinogen, subsequently activated with thrombin and held with pressure for 1 to 2 minutes.17 Specific bleeding vessels or collecting system openings were not identified prior to bandage placement. The bandage was secured with argon beam coagulation. The whole specimen was sent for frozen section of the inked base margin. While awaiting the results of frozen section (20 to 30 minutes), renal turgor was increased with hydration with selective use of diuretics. Intraperitoneal pressure was decreased to assess bleeding or urine leakage. In 5 specimens with a positive focal margin the bandage was removed and the bed was re-resected. With all final margins negative the hemostatic process was repeated. Gerota’s fascia was reapproximated around the kidney and a closed suction drain was left in the retroperitoneum via a lateral port site. RESULTS

Eight patients (26.7%) had a compromised contralateral kidney (table 2) and, thus, an absolute indication for PN (table 2). Five patients (16.7%) had relative indications for nephron sparing surgery, eg diabetes. Slightly longer OR (233 minutes) and EBL (519 ml) was noted in 14 patients (46.7%) with prior intra-abdominal surgery. Table 3 lists perioperative parameters. Two central lesion cases received intraoperative transfusion (EBL 1,000 and 2,100 ml, respectively), and 2 central and 2 peripheral cases received transfusion for postoperative anemia (hemoglobin 7.0 to 8.4 g/dl). Anemia was attributable to postoperative bleeding in 2 cases, and to chronic anemia and/or dilutional hypervolemia in 2. Mean preoperative hemoglobin was 13.5 gm/dl. In patients not receiving intraoperative transfusion, hemoglobin the night of surgery was 11.0 gm/dl and postoperative day (POD) 1 hemoglobin was 11.2 gm/dl. A total of 13 patients had stable POD 2 hemoglobin compared to POD 1 (10.8 vs 10.9 gm/dl). One patient with a 3.5 cm central lesion, an EBL of 350 ml and normal preoperative hemoglobin re-

Stifelman et al18 Transperitoneal HALPN 11 1.9 Not available 319 273 3.3 1 0 0 0 0 0 Not available 8

Gill et al19

Rassweiler et al8

Transperitoneal, retroperitoneal pure laparoscopic

Transperitoneal, retroperitoneal, pure laparoscopic

50 3.0 9 (18) 270 180 2.2

53 2.3 Not available 725 191 5.4

0 1 1 1 2 (4) 2 (4)

4 5 2 1 Not available 6 (11)

Not available 7.2

Not available 24

TABLE 2. Demographics and final pathological data on patients treated with HALPN No. pts No. men/women Mean age ⫾ SD No. prior intra-abdominal surgery (%) No. normal contralat kidney (%) No. compromised contralat kidney history (%): Contralat radical nephrectomy Contralat staghorn calculus Nonfunctioning atrophic contralat kidney Donor nephrectomy Contralat partial nephrectomy No. RCC (%): Clear cell Papillary Chromophobe No. angiomyolipoma (%) No. oncocytoma (%) No. benign (%) No. RCC pathological tumor stage: T1N0M0 T2N0M0 T3N0M0

30 16/14 55 ⫾ 13 14 (47) 22 (73) 8 (27) 2 2 2 1 1 21 (70) 14 5 2 4 (13) 2 (7) 3 (10) 19 0 2

ceived a 2 unit transfusion postoperatively for a verified hemoglobin of 7.5 gm/dl. Although hemoglobin increased to 8.5 gm/dl after transfusion, it decreased to 7.1 gm/dl on POD 2, requiring 2 additional units for presumed hemorrhage. Final hemoglobin was 12.9 gm/dl at discharge home on POD 7. The patient was asymptomatic and imaging was not done. Mean preoperative, night of surgery, and PODs 1 and 2 serum creatinine was 0.91 mg/dl in 30 cases, 1.06 in 29, 1.07 in 30 and 0.93 in 17. A 0.15 mg/dl increase in creatinine observed within the first 24 hours normalized by POD 2. Two patients with a solitary kidney had a 0.2 mg/dl increase on POD 1 but neither had a POD 2 determination. Creatinine returned to baseline at followup. In another patient with a solitary kidney discharge serum creatinine was 0.1 mg/dl lower than preoperatively. In 6 central (75%) and 21 peripheral (95.5%) tumor cases the drain was removed during hospitalization. The mean POD of drain removal was 3.3 (range 2 to 5) and 2.5 (range 2 to 5) for central and peripheral lesions, respectively. On POD 1 drain creatinine was measured routinely. In 24 patients (80%) the value was equivalent to serum and in 6 (20%) it was elevated, including 3 with a central (re-resection in 1) and 3 with a peripheral (re-resection in 1) lesion. In 2 patients with a central and 1 with a peripheral tumor drain creatinine normalized by POD 5 and the drain was removed. In 1 patient with a central and 1 with a peripheral tumor repeat drain creatinine was elevated but decreasing in vol-

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HAND ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY TABLE 3. Perioperative parameters Mean cm size ⫾ SD (range) Mean cc EBL ⫾ SD (range) Mean mins time ⫾ SD (range) Mean days hospital stay ⫾ SD (range) No. transfusion/total No. (%)

Entire Series

Peripheral

Central

2.6 ⫾ 0.9 (1.0–4.7) 415 ⫾ 401 (50–2,100) 218 ⫾ 64 (90–332) 4.0 ⫾ 1.8 (1–10) 6/30 (20)

2.4 ⫾ 1.7 (1.0–4.0) 240 ⫾ 113 (50–450) 199 ⫾ 41 (90–265) 3.5 ⫾ 1.9 (1–10) 2/22 (9.1)

3.2 ⫾ 0.9 (2.1–4.7) 894 ⫾ 552 (350–2,100) 271 ⫾ 48 (195–332) 4.6 ⫾ 1.7 (3–7) 4/8 (50)

ume at discharge home with the drain. In each patient leakage resolved within 2 weeks. One central tumor case had persistent leakage at 2 weeks. Retrograde pyelography revealed clot in the proximal ureter and focal urine leakage from an inferior pole calix. A Double-J (Medical Engineering Corp., New York, New York) stent and Foley catheter were placed and leakage resolved within 48 hours. Patients ambulated, tolerated liquids, passed flatus and were discharged home at a mean of 1.2, 1.4, 3.1 and 4 days, respectively. Mean hospital stay was slightly longer for central lesions (4.6 vs 3.5 days). Table 2 lists pathological data. Table 4 shows frozen section assessment. The whole specimen deep margin was inked and analyzed. In 5 of 30 lesions (16.7%), including 1 central (12.5%) and 4 peripheral (18.2%) lesions, there was a focal positive margin on frozen section. In 3 patients the first re-resection was negative and in 2 the first re-resection was positive for tumor with 1 requiring repeat deep resection to clear the margin. Of 16 renal cell carcinoma (RCC) cases with a negative initial margin the tumor encroached to less than 1 mm, to approximately 1 mm and to within 2 mm in 1, 4 and 4, respectively. No patient had evidence of persistent cancer at a mean followup of 8.8 months. In 1 centrally located tumor case a benign cyst that was 1 cm at HALPN subsequently enlarged to a 3 cm complex cystic mass 18 months later and cystic RCC was removed by HAL nephrectomy. Table 5 lists complications. Tumors were classified as central or peripheral at surgery if they were less or greater than 5 mm from collecting system or hilar vasculature, respectively. To compare further tumor distances to the renal pelvis we repeated CT in 6 central and 2 peripheral cases. The measured distance from the margin of the tumor to the pelvicaliceal system was 2.5 mm (range 0 to 8) for central lesions and 12 mm (range 6 to 18) for peripheral lesions. There was no measurable distance between the collecting system and 3 central lesions. One mid pole lesion 8 mm from the collecting system was classified as central due to its hilar vessel proximity. DISCUSSION

Laparoscopic advances of the last decade have led to changes in the management of renal masses with the role of laparoscopic intervention debated in this setting.17, 19 Further controversy involves whether standard LPN or HALPN laparoscopic intervention should be used in renal surgery.20, 21 More information is needed regarding pathological outcome, recurrence rates, and perioperative and postoperative morbidity to determine which if either technique is superior. We report the largest HALPN series to date, which is

to our knowledge the first study to compare the outcomes of central vs peripheral lesions. This series compares favorably with others in terms of tumor size, operative time and morbidity (table 1). Our mean EBL is higher and transfusion rate greater than that of others,19 which may reflect the lack of hilar clamping, especially for central lesions. Another difference is the higher rate of initial positive margins. Gill et al described 1 patient with a “questionable” positive margin that was considered a surgical artifact.19 While our final positive margin rate was 0%, it required re-resection in 5 cases. It is unclear whether this outcome reflects inadequate resection and/or more extensive pathological evaluation of the margin. Another possibility is the involvement of multiple surgeons performing our cases. Positive margin cases occurred more frequently early in surgeon experience (data not shown). It is simple to remove the bandage and re-resect the bed with manual renal compression if needed. This situation could be more difficult during LPN with hilar occlusion. More attention is now given to take a wider margin (5 to 7 mm) by initially resecting along pyramidal lines to minimize the need for re-resection. We had a 20% transfusion rate compared with the 0% to 10% rates previously reported.17, 18 This difference could have been due to a higher percent of centrally located tumors and/or larger average tumor size, which was up to 0.8 cm greater. However, when multiplied by 3, our mean hemoglobin decrease is identical to the hematocrit change in the series of Stifelman et al.18 Based on our findings central lesions should be considered for hilar clamping. Our hospital stay was slightly longer (4.0 vs 3.2 days) than in others series. Our 6.7% major complication rate (2 of 30 cases) was greater than the 0% reported previously, as was our urine leakage rate of 20%.17, 18 The latter is a reflection of our strict definition of leakage and routine drain fluid creatinine measurement. While others do not do this routinely, we use this information to determine the timing of drain removal. In 6 patients with urine leakage it resolved spontaneously in 3 within 5 days and in 2 within 2 weeks. Drains were removed during hospitalization in 6 (75%) central and 21 peripheral (95.5%) tumor cases with central lesion drains remaining approximately 1 day longer (3.3 vs 2.5 days). Only 1 central tumor case required Double-J stent placement on POD 16. When comparing central vs peripheral lesions, we noted greater OR time (271 vs 199 minutes), EBL (894 vs 240 ml), transfusion rate (50% vs 9.1%), urine leakage rate (37.5% vs 13.6%) and complication rate (50% or 2 major and 2 minor vs

TABLE 5. HALPN complications in 30 consecutive cases TABLE 4. Intraoperative frozen section pathological findings No. Entire Series (%) Enhancing mass 30 RCC 21 (70) Initial margin: Neg 16 Pos 5 (17) Re-excision ⫹ pos margin: 1 2 2 0 No positive margins on final pathological study.

No. Peripheral (%)

No. Central (%)

22 14 (64)

8 7 (88)

10 4 (18)

6 1 (12.5)

1 0

1 0

No. Peripheral

No. Central

Persistent Jackson-Pratt drain 1 2 creatinine elevation* Hemorrhage requiring transfusion: Intraop 0 2 Delayed 0 1 Transfusion for symptomatic anemia 2 1 Surgical re-intervention 0 1 Ileus 1 0 There was no conversion to open surgery, kidney loss or positive margins on final pathological study. * Drain remaining in place longer than 5 PODs.

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HAND ASSISTED LAPAROSCOPIC PARTIAL NEPHRECTOMY

13.6% or 3 minor). There was a lower positive margin rate in central lesions (12.5% vs 18.2%). Although it was unexpected, this finding emphasizes the feasibility of treating central tumors with HALPN. All 8 central tumors were in the first 20 cases, making learning curve analysis difficult. All cases requiring transfusion were among our first 15 and mean EBL in our first 20 vs last 10 was dramatically different (533 and 180 ml, respectively). If central lesions were eliminated from the initial 20 cases, mean EBL would decrease to 292 ml. In the initial 20 patients OR time was 222 minutes, that is 193 with central lesions excluded. OR time for the last 10 patients was 208 minutes. All except 2 minor complications (ileus and urine leakage) were in the first 20 cases. It is unclear whether this outcome was related to the learning curve or to the early predominance of central lesions. Our data support the concept that renal lesions may be classified as high risk (central and endophytic) or low risk (peripheral and exophytic). Laparoscopic surgical techniques should mimic proven open technique principles and continual reassessment with new technology and outcomes data is imperative. The fibrin glue bandage is an example of the former, while the acceptance of 1 to 2 mm margins as sufficient during PN is an example of the latter. Our study suggests that closure of small urothelial disruptions during PN for peripheral tumors may be less important that previously thought. Based on these results we recommend renal hilar vessel clamping and renal parenchyma/capsule reapproximation over the fibrin glue bandage with or without a roll of oxycellulose cotton as standard for central lesions. We do not oversew vessels or urothelial defects, or place Double-J stents at surgery, but rather place bolstering sutures to reapproximate the parenchyma. We selectively use intravenous indigo carmine if there is concern about collecting system integrity. What is the partial nephrectomy standard for smaller exophytic or peripherally located renal tumors? While many groups use the open surgical approach of vessel clamping with or without regional hypothermia, others favor resection using manual parenchymal compression to avoid the risks of hilar dissection, clamping and complete renal ischemia. While advocates for hilar clamping argue that total renal ischemia is less nephrotoxic than intermittent ischemia, proponents of manual parenchymal compression counter that hand compression is different than intermittent vessel clamping because much and possibly most of the kidney is never ischemic. Followup serum creatinine in our solitary kidney cases is similar to that in the 4 cases of Gill et al,19 suggesting that manual compression might not cause significant renal injury. CONCLUSIONS

This study demonstrates several findings of HALPN without hilar clamping. 1) There is a 3 to 4-fold increase in EBL, transfusion rate and urinary leakage in central vs peripheral lesion cases. Consideration should be given to clamping the renal hilum and reapproximating the renal capsule/parenchyma in such cases. 2) The flexibility of reapplying hand compression and the fibrin glue bandage in the face of a positive margin is an advantage of HALPN. 3) HALPN appears to be a good nephron sparing technique with minimal changes in serum creatinine, including in patients with a solitary kidney. Further analysis of all PN techniques may clarify whether there are any differences in cancer control, renal ischemia/preservation, surgical complications and morbidity.

REFERENCES

1. McDougall, E. M., Clayman, R. V., Chandhoke, P. S., Kerbl, K., Stone, A. M., Wick, M. R. et al: Laparoscopic partial nephrectomy in the pig model. J Urol, 149: 1633, 1993 2. Winfield, H. N., Donovan, J. F., Godet, A. S. and Clayman, R. V.: Laparoscopic partial nephrectomy: initial case report for benign disease. J Endourol, 7: 521, 1993 3. Gill, I. S., Delworth, M. G. and Munch, L. C.: Laparoscopic retroperitoneal partial nephrectomy. J Urol, 152: 1539, 1994 4. McDougall, E. M., Elbahnasy, A. M. and Clayman, R. V.: Laparoscopic wedge resection and partial nephrectomy—the Washington University experience and review of the literature. JSLS, 2: 15, 1998 5. Janetschek, G., Jeschke, K., Peschal, R., Strohmeyer, D., Henning, K. and Bartsch, G.: Laparoscopic surgery for stage T1 renal cell carcinoma: radical nephrectomy and wedge resection. Eur Urol, 38: 131, 2000 6. Hoznek, A., Salomon, L., Antiphon, P., Radier, C., Hafiani, M., Chopin, D. K. et al: Partial nephrectomy with retroperitoneal laparoscopy. J Urol, 162: 1922, 1999 7. Harmon, W. J., Kavoussi, L. R. and Bishoff, J. T.: Laparoscopic nephron-sparing surgery for solid renal masses using the ultrasonic shears. Urology, 56: 754, 2000 8. Rassweiler, J. J., Abbou, C., Janetschek, G. and Jeschke, K.: Laparoscopic partial nephrectomy. The European experience. Urol Clin North Am, 27: 721, 2000 9. Shekarriz, H., Shekarriz, B., Upadhyay, J., Bu¨ rk, C., Wood, D. P., Jr. and Bruch, H.-P.: Hydro-jet assisted laparoscopic partial nephrectomy: initial experience in a porcine model. J Urol, 163: 1005, 2000 10. Winfield, H. N., Donovan, J. F., Lund, G. O., Kreder, K. J., Stanley, K. E., Brown, B. P. et al: Laparoscopic partial nephrectomy: initial experience and comparison to the open surgical approach. J Urol, 153: 1409, 1995 11. Cadeddu, J. A., Corwin, T. S., Traxer, O., Collick, C., Saboorian, H. H. and Pearle, M. S.: Hemoastatic laparoscopic partial nephrectomy: cable-tie compression. Urology, 57: 562, 2001 12. McGinnis, D. E., Strup, S. E. and Gomella, L. G.: Management of hemorrhage during laparoscopy. J Endourol, 14: 915, 2000 13. Barret, E., Guillonneau, B., Cathelineau, X., Validire, P. and Vallancien, G.: Laparoscopic partial nephrectomy in the pig: comparison of three hemostasis techniques. J Endourol, 15: 307, 2001 14. Yoshimura, K., Okubo, K., Ichioka, K., Terada, N., Matsuta, Y. and Arai, Y.: Laparoscopic partial nephrectomy with a microwave tissue coagulator for small renal tumor. J Urol, 165: 1893, 2001 15. Gettman, M. T., Bishoff, J. T., Su, L. M., Chan, D., Kavoussi, L. R., Jarrett, T. W. et al: Hemostatic laparoscopic partial nephrectomy: initial experience with the radiofrequency coagulation-assisted technique. Urology, 58: 8, 2001 16. Elashry, O. M., Wolf, J. S., Jr., Rayala, H. J., McDougall, E. M. and Clayman, R. V.: Recent advances in laparoscopic partial nephrectomy: comparative study of electrosurgical snare electrode and ultrasound dissection. J Endourol, 11: 15, 1997 17. Wolf, J. S., Jr., Seifman, B. D. and Montie, J. E.: Nephron sparing surgery for suspected malignancy: open surgery compared to laparoscopy with selective use of hand assistance. J Urol, 163: 1659, 2000 18. Stifelman, M. D., Sosa, R. E., Nakada, S. Y. and Shichman, S. J.: Hand-assisted laparoscopic partial nephrectomy. J Endourol, 15: 161, 2001 19. Gill, I. S., Desai, M. M., Kaouk, J. H., Meraney, A. M., Murphy, D. P., Sun, G. T. et al: Laparoscopic partial nephrectomy for renal tumor: duplicating open surgical techniques. J Urol, 167: 469, 2002 20. Wolf, J. S., Jr.: Hand-assisted laparoscopy: pro. Urology, 58: 301, 2001 21. Gill, I. S.: Hand-assisted laparoscopy: con. Urology, 58: 313, 2001