660 LAPAROSCOPIC COMPLEX PARTIAL NEPHRECTOMY: TECHNIQUE AND FEASIBILITY

657

Partial nephrectomy without ischemia: Evaluation of a new radiofrequency-based bi-polar resection device (HabibTM 4X) in a perfused organ-model of porcine kidneys

Engeler D.S.1, Leippold T.1, Hobi C.1, Zerz A.2, Marlovits H.2, Hell M.3, Diener P.A.3, Schmid H.P.1 Cantonal Hospital of St. Gallen, Department of Urology, St. Gallen, Switzerland, 2Cantonal Hospital of St. Gallen, Department of Surgery, St. Gallen, Switzerland, 3Cantonal Hospital of St. Gallen, Department of Pathology, St. Gallen, Switzerland 1

Introduction & Objectives: The device has been recently developed for liver surgery. We are now exploring the efficiency and the handling of this new bi-polar resection device in kidney applications. Using a perfused organ model of porcine kidneys, the applicability and efficiency as well as the tissue effect are studied. Material & Methods: For the experiment, a pulsating organ perfusion (POP) trainer was used to simulate organ perfusion. We used a freshly excised retroperitoneal tissue block containing both kidneys including all vascular structures. The tissue was kept on ice until the experiment took place the same day. The aorta was used for the inflow of water - without red dye for histological analysis, then with red dye for the evaluation of the vascular control. The device was then used for resection of the upper or lower poles in a circular manner and tissue was resected using scalpel or scisors. Finally, the treated renal tissue was analysed by conventional H&E staining and fluorescence microscopy using an in situ cell death detection technique (TdT-mediated dUTP-X nick end labelling (TUNEL) technology). Results: The ablation of a pole in all cases (n=4) took only few minutes depending on the diameter (5-7 cm). The ablated tissue could be excised without any problem with the scalpel or the scissors without leakage of blood simulating fluid. As an advantage the treated tissue showed stronger hold for suture material. The thickness of the histologically defined necrotic area was about 10mm. The analysed tissue of the treated in contrast to normal renal parenchyma showed marked eosinophilic cytoplasm in conjunction with caryopyknosis as a sign of necrosis. Cell death (TUNEL positivity) under fluorescence was only present at the electrode insertion site without relevant amounts of TUNEL positive cells outside the treated area. Conclusions: This new radiofrequency-based bipolar resection device allows efficient and rapid tissue ablation without the need for kidney ischemia. Tissue structure is nicely preserved allowing interpretation of resection margins and there is only minimal collateral tissue damage. Meanwhile, the device has been successfully used in human partial nephrectomies at our institution.



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658

Laparoscopic partial nephrectomy using renal artery perfusion for cold ischemia

Beri A.1, Lattouf J.B.1, De Ambros O.1, Grüll M.1, Gschwendtner M.2, Ziegerhofer J.3, Leeb K.1, Janetschek G.1 Krankenhaus der Elisabethinen, Urology, Linz, Austria, 2Krankenhaus der Elisabethinen, Radiology, Linz, Austria, 3Krankenhaus der Elisabethinen, Nuclear Medicine, Linz, Austria 1

Introduction & Objectives: We present our technique and long term oncologic and functional outcomes of laparoscopic partial nephrectomy under cold ischemia using a renal artery perfusion method. Material & Methods: Between April 2000 and September 2006, 94 laparoscopic partial nephrectomies were performed at our institution. Twenty eight (29.8%) of them were performed with cold ischemia. The indication for cold ischemia was an anticipation of a long ischemia time (i.e. central, hilar or multiple lesions). Mean tumor size was 2.67 cm (range 1.5 – 5). Five patients (17.9%) had an imperative indication for partial nephrectomy. Eight (28.6%) tumors were hilar. Access to the renal artery was obtained angiographically in the operating theatre prior to initiation of surgery. Intra-operative artery clamping was followed by perfusion with 4◦C mannitol in lactated ringer hypertonic solution. Results: Mean ischemia time was 40.8 min (range 25 – 86). Mean estimated blood loss was 241mL (range 50-1000). Three patients (10.7%) underwent conversion to open surgery. One (3.6%) intra-operative and 2 (7.2%) post-operative complications took place including segmental artery lesion, pancreatitis and pulmonary embolism. Functional studies revealed mild decrease in creatinine clearance in immediate post-operative period, with improvement 3 months after the surgery. Nuclear scans showed functional kidney moiety in all but one case. Median split renal function on the operated side was 40%. Histo-pathological examination confirmed renal cell carcinoma in 23 (82.1%) patients. One patient (4.3%) with chromophobe renal cell carcinoma had a positive surgical margin on the surface that was adjacent to the renal artery. In a median follow-up of 4 years, no local recurrence or systemic progression occurred. Conclusions: Intra-operative cold ischemia for laparoscopic partial nephrectomy using arterial perfusion is a safe and feasible method. It constitutes a viable alternative for complex renal tumors where long ischemia time is anticipated.



660

Assessment of preoperative risk factors for complications of laparoscopic partial nephrectomy

Laparoscopic Complex Partial Nephrectomy: Technique and Feasibility

Porpiglia F., Volpe A., Billia M., Renard J., Tarabuzzi R., Terrone C., Scarpa R.M.

Pettus J., Guillonneau B., Touijer K.

University of Turin, Dept. of Biological and Clinical Science, Dept. of Urology, San Luigi Hospital, Orbassano, Italy

Memorial Sloan Kettering, Urology, New York, NY, United States of America

Introduction & Objectives: Laparoscopic partial nephrectomy (LPN) is emerging as an attractive option for the treatment of small renal tumors. However, it is a challenging technique and the complication rate is still significant. The identification of preoperative risk factors for complications may allow a better patient selection and therefore lower complication rates. Material & Methods: From January 2001 to June 2006, 80 patients underwent LPN at our centre for a clinically localized renal tumor. All procedures were performed by a single, experienced laparoscopic surgeon. All patients had a normal contralateral kidney. A retrospective chart review was carried out in order to identify patient and tumor features as well as details of surgical techniques that were correlated with a higher risk of intra and postoperative complications. We also evaluated the impact of the learning curve on the risk of complications by looking at the postoperative complication rate in the first 40 and the last 40 LPNs of our series. Results: No intraoperative complications occurred and no case had to be converted to open surgery. We observed postoperative complications in 13 patients (16.3%). 6 patients had acute haemorrhage postoperatively (3 underwent surgery and 3 were treated by selective arterial embolization). Urine leakage was observed in 3 cases, all treated successfully with ureteral stenting for an average of 30 days. 4 patients developed an abdominal hematoma, which always resolved spontaneously without drainage. At univariate analysis no patient or tumor feature was significantly correlated with the occurrence of postoperative complications. 24.4% of patients experienced postoperative complications when suture alone was used to achieve the hemostasis, while 9.1% patients had complications when sealants were used as well (p=n.s.) The complication rate was not statistically higher in the first part of our learning curve. Conclusions: LPN is a challenging procedure for all renal tumors with a hardly predictable risk of complications and should be therefore limited to centres with high laparoscopic expertise.

Introduction & Objectives: With gained experience, indications of laparoscopic partial nephrectomy (LPN) have expanded from small, peripherally located tumors to centrally located tumors requiring complex intracorporeal suturing and reconstruction with the constraints of renal ischemia. We report our experience of LPN for complex renal cortical tumors Material & Methods: We reviewed our prospectively-collected nephrectomy database for all LPNs done at our institution. We defined complex tumor as being completely endophytic and/or involving the hilum or the renal sinus fat based on the preoperative abdominal imaging studies. All imaging studies were reviewed with a referee radiologist for the purpose of the study. Results: A total of 24 patients were identifies with a median follow up of 6 (1, 12) months and median age 57 (46, 65) who underwent LPN. All cases required renal arterial clamping with a median ischemic time of 38 (26, 52) minutes, and more than one renal artery was identified and clamped in 10 (42%). Cold ischemia through a ureteral stent was utilized in 11 (48%) cases. The collecting system required suture repair in 15 (63%). Median blood loss was 165 (100, 305) cc, and the median operative time was 257 (206, 283) min. The median tumor size was 2.7 (2, 3.5) cm. Three (13%) tumors were pT3a while the remainder lesions were pT1.The final tumor pathology was clear cell renal cell carcinoma (RCC) in 11 (48%), papillary RCC in 4 (21%), oncocytoma in 3 (13%), chromophobe RCC in 2 (8%), spindle cell in 4%, mixed epithelial in 1 (4%), and benign cyst in 1 (4%). There were no positive surgical margins. A total of 9 complications occurred in 6 (25%) patients, including 2 patients who required angiographic embolization for intrarenal pseudoaneurysm. Conclusions: Laparoscopic partial nephrectomy is feasible in patients with complex renal tumors. The safety and feasibility of such a procedure depends on the surgeon’s experience with the execution of complex laparoscopic tasks.

Eur Urol Suppl 2007;6(2):187