Laparoscopic radical nephrectomy in 100 patients: a single center experience from the United States.

BACKGROUND: The objective of the current study was to report a single-surgeon, single-center experience with 100 consecutive laparoscopic radical nephrectomies with intact specimen extraction, with the aim of evaluating the oncologic adequacy of the laparoscopic dissection from a technical standpoint and various parameters including the learning curve. METHODS: Of the 140 laparoscopic radical nephrectomies performed at the study institution since August 1997, the initial 100 are evaluated herein. To evaluate the technical oncologic adequacy, comparison was made with 40 contemporary open radical nephrectomy specimens with regard to detailed radiologic (computed tomography scan) and pathologic data. RESULTS: In the 100 patients studied (with a mean tumor size of 5.1 cm), the mean surgical time was 2.8 hours, the blood loss was 212 mL, the specimen weight was 554.3 g, and the hospital stay was 1.6 days. Complications occurred in 14 patients (14%) and were major in 3 (3%) and minor in 11 (11%). Two patients (2%) were converted to open surgery. There was no perioperative mortality. Over a mean follow-up of 16.1 months, there was no local or port site recurrence reported; 2 patients developed metastatic disease with 1 death occurring at 11 months. When evaluating the learning curve in the initial 50 versus the second 50 patients, a shorter surgical time (P = 0.02) appeared to be the only significant variable. On multivariate analyses, the only variables found to impact on surgical time were specimen weight (P < 0.001) and chronologic time period of surgery (P = 0.05). All laparoscopic specimens were extracted intact; surgical margins were negative for tumor in all 100 patients. All detailed radiologic and histopathologic parameters evaluated were nearly identical between the laparoscopic and open surgery groups. CONCLUSIONS: Laparoscopic radical nephrectomy with intact specimen extraction currently is a routine, effective, and efficacious treatment option for patients with T1-T3aN0M0 renal tumors. Although no long-term data were available as of last follow-up, the negative surgical margins achieved routinely in the current series provide encouraging surrogate evidence of the technical efficacy of laparoscopy from an oncologic standpoint. As such, at the study institution, laparoscopic radical nephrectomy with intact specimen extraction currently is the standard-of-care for patients with T1-3aN0M0 renal tumors measuring < or = 10-12 cm in size.

Laparoscopic renal cryoablation: impact on renal function and blood pressure.

OBJECTIVES: To evaluate the renal function and blood pressure outcomes after laparoscopic renal cryotherapy. Laparoscopic renal cryoablation is a developmental minimally invasive modality for the treatment of renal neoplasms. After cryotherapy, a segment of renal parenchyma is rendered ischemic/necrotic and left in situ. It is currently unknown whether this may trigger renin overproduction and thus renin-mediated hypertension. METHODS: Data are presented for 22 of 56 treated patients, each of whom completed a minimum follow-up of 6 months. The data were obtained from patient charts, phone interviews, and/or questionnaires. These results were statistically compared over time by paired t tests. RESULTS: The mean follow-up was 20.6 months. No significant differences were found between the preoperative and most recent postoperative serum creatinine (sCr) levels (1.13 and 0.91 mg/dL, respectively), systolic and diastolic blood pressure values (135.6 versus 131.2 mm Hg and 78 versus 72.7 mm Hg, respectively), or in the estimated creatinine clearance (P <0.05). The number or dose of antihypertensive medications did not change during the follow-up period for any patient. In 3 patients with a solitary kidney, the blood pressure and sCr values remained unchanged (mean preoperative sCr 1.43 mg/dL and mean postoperative sCr after a minimum of 6 months 1.33 mg/dL). CONCLUSIONS: Laparoscopic renal cryoablation did not have a deleterious impact on renal function or blood pressure during a mean follow-up of 20.6 months.

Laparoscopic repair of renal artery aneurysm.

PURPOSE: We describe technical considerations of the laparoscopic repair of a renal artery aneurysm. MATERIALS AND METHODS: A 57-year-old woman presented with a 3 cm. aneurysm of the distal left main renal artery at its bifurcation. Using a purely laparoscopic 4-port transperitoneal technique the aneurysm was completely mobilized from its location behind the renal vein. Its 3 feeding vessels were controlled individually with bulldog clamps. The aneurysm sac was bivalved and precisely trimmed to conform with the diameter of the main renal artery. Vascular reconstruction was performed with running freehand laparoscopic suturing and intracorporeal knot tying using 4-zero polypropylene suture. RESULTS: Warm ischemia time was 31 minutes, total operative time was 4.2 hours, blood loss was 100 cc and hospital stay was 2 days. Postoperatively renal scan showed improved perfusion and renal arteriography confirmed adequate repair of the aneurysm. CONCLUSIONS: Laparoscopic repair of the renal artery aneurysm is feasible. To our knowledge we present the initial clinical report of laparoscopic renovascular surgery in the literature.

Laparoscopic intracorporeally constructed ileal conduit after porcine cystoprostatectomy.

PURPOSE: We present our technique of laparoscopic ileal conduit creation after cystoprostatectomy in a porcine model performed in a completely intracorporeal manner. METHODS AND METHODS: After developing the technique in 5 acute animals laparoscopic cystoprostatectomy with intracorporeally performed ileal conduit urinary diversion was performed in 10 surviving male pigs. A 5-port transperitoneal technique was used. All steps of the technique applied during open surgery were duplicated intracorporeally. Specifically cystectomy, isolation of an ileal conduit, restoration of bowel continuity and mucosa-to-mucosa stented bilateral ileoureteral anastomosis formation were performed by exclusively intracorporeal laparoscopic techniques. RESULTS: Surgery was successful in all 10 study animals without intraoperative or immediate postoperative complications. Blood loss was minimal and average operative time was 200 minutes. Stenosis of the end ileal stoma specifically at the skin level was noted in 6 animals. Three deaths occurred 2 to 3 weeks postoperatively. At sacrifice renal function was normal in all surviving animals. No ileo-ureteral anastomotic strictures were noted on pre-sacrifice radiography of the loop or at autopsy examination of the anastomotic sites. CONCLUSIONS: Laparoscopic ileal conduit urinary diversion after cystoprostatectomy may be performed completely intracorporeally in the porcine model. Clinical application of this technique is imminent.

Laparoscopic right adrenalectomy after liver transplantation.

To our knowledge, laparoscopic right adrenalectomy has not been previously reported after orthotopic liver transplantation. The aim of this report is to demonstrate the feasibility of the laparoscopic approach in this technically challenging situation, and to outline some considerations unique to this clinical setting.

Thoracoscopic transdiaphragmatic adrenalectomy: the initial experience.

PURPOSE: We introduce the technique of thoracoscopic transdiaphragmatic adrenalectomy. MATERIALS AND METHODS: Initially in 4 human cadavers bilateral thoracoscopic nephrectomy was performed to develop the technique of diaphragmatic incision, retroperitoneal control of renal artery and vein, circumferential mobilization of the kidney and adrenal gland, and suture repair of the diaphragm. Subsequently, 3 select patients underwent thoracoscopic transdiaphragmatic adrenalectomy (2 right side and 1 left side). All 3 patients had significant prior abdominal scarring after either partial or total radical nephrectomy, thereby precluding efficient transabdominal laparoscopic access to the adrenal gland. After double lumen endotracheal intubation, a 4 port transthoracic approach without pneumo-insufflation was performed with the patient in the prone position. The diaphragm was incised under real-time laparoscopic ultrasound guidance. The adrenal gland was visualized high in the retroperitoneum, the vasculature controlled, and the specimen entrapped and extracted intact through a thoracic port site. The diaphragm was suture repaired with freehand laparoscopic suturing and intracorporeal knot tying. A chest tube was inserted in the initial 2 patients. RESULTS: There were no intraoperative or postoperative complications. Operating time was 4.5, 6.5 and 2.5 hours, and blood loss was 150, 500 and 50 cc, respectively. Mean narcotic analgesic requirement was 27 mg. morphine sulfate equivalent. Hospital stay was 2 days for all 3 patients. Pathology revealed metastatic renal cell carcinoma in 2 patients and myelolipoma in 1. CONCLUSIONS: In select patients with significant concomitant intraperitoneal and retroperitoneal scarring from prior major abdominal or renal surgery laparoscopic adrenalectomy can be safely performed with the transthoracic transdiaphragmatic approach. We present our initial experience.

Laparoscopic renal autotransplantation.

BACKGROUND AND PURPOSE: Renal autotransplantation is an extensive open surgical operation consisting of two distinct procedures, live-donor nephrectomy and autotransplantation, and requiring two large skin incisions. Herein, we analyze the feasibility of performing the entire procedure laparoscopically. MATERIALS AND METHODS: Renal autotransplantation was performed entirely laparoscopically in six female farm pigs. Following a left donor nephrectomy, intracorporeal renal hypothermia was achieved by intra-arterial perfusion of ice-cold solution through a 4F balloon catheter. During autotransplantation, the renal vessels were anastomosed intracorporeally to the previously prepared ipsilateral common iliac vessels in an end-to-side fashion. Laparoscopic freehand suturing (5-0 Prolene) and knot-tying techniques were employed exclusively. A staged contralateral native nephrectomy was performed in five animals. Postoperative follow-up included serial creatinine measurements, intravenous urography, aortography, and renal histologic examination. RESULTS: The mean operating time was 6.2 hours (range 5.3-7.9 hours), the venous anastomosis time was 33 minutes (range 22-46 minutes), the arterial anastomosis time was 31 minutes (range 27-35 minutes), and the total iliac clamping time was 77 minutes (range 62-88 minutes). The total renal ischemia time was 68.7 minutes: warm ischemia 5.1 minutes, cold ischemia 33 minutes and rewarming 31 minutes. Serum creatinine concentrations remained stable: baseline 1.3 mg/dL, after autotransplantation 1.1 mg/dL, and after contralateral nephrectomy 1.6 mg/dL. Intravenous urography and aortography prior to euthanasia (N = 5) demonstrated prompt contrast uptake and excretion by the autotransplanted kidneys and patent arterial anastomoses, respectively. Histopathologic examination of the autograft demonstrated normal renal architecture. CONCLUSIONS: Renal autotransplantation can be performed utilizing laparoscopic techniques exclusively. This study may form the basis for performance of complex urologic vascular procedures laparoscopically.

Laparoscopic orthotopic ileal neobladder.

BACKGROUND AND PURPOSE: Orthotopic ileal neobladder is currently the preferred continent urinary diversion in suitable patients undergoing radical cystectomy for muscle-invasive bladder cancer. To our knowledge, presented herein is the initial report of laparoscopic orthotopic ileal neobladder following cystectomy that was performed completely intracorporeally in a porcine model. MATERIALS AND METHODS: The laparoscopic technique was developed in seven pigs. Subsequently, a long-term survival study was performed in 12 consecutive animals. Laparoscopic cystectomy was performed, preserving the urethral sphincter. An ileal segment of 35 cm (first three animals), 45 cm (next four), or 55 cm (final five animals) with adequate mesentery was isolated; and ileal continuity was restored intracorporeally by a stapled anastomosis. Ileal detubularization for construction of an ileal neobladder, urethroileal anastomosis, and bilateral stented ileoureteral anastomoses to a tubular Studer limb extension were all created completely intracorporeally using only laparoscopic free-hand suturing and knot-tying. Biochemical data (preoperative and serial postoperative hemoglobin, renal panel, blood gases), radiologic studies (intravenous urogram, retrograde pouchgram), functional measures (neobladder urodynamics, Whitaker pressure-flow study of both ureters), and microscopic evaluation of the neobladder and ureteroileal and urethroileal anastomotic sites were obtained to evaluate the long-term functional and anatomic outcome. RESULTS: Completely intracorporeal laparoscopic construction of an ileal orthotopic neobladder was successful in all 12 animals without intraoperative or early postoperative complications or open conversion. The mean operating time was 5.4 hours (range 4.5-6.5 hours), and the blood loss was minimal. All study pigs survived their predetermined follow-up period, ranging from 1 to 3 months. Late complications occurred in three animals: one port-site abscess and two cases of E. coli pyelonephritis and azotemia, leading to one death at 2 months. The mean serum creatinine concentrations were 1.33 mg/dL, 1.61 mg/dL, and 1.55 mg/dL at 1, 2, and 3 months, respectively. The mean neobladder capacity was 420 mL (range 250-700 mL) with pressures < or = 20 cm H2O (range 17-20 cm H2O). Pre-euthanasia Whitaker testing confirmed excellent drainage in all 24 ureters. No ileoureteral or ileourethral anastomotic strictures or leaks were noted on intravenous urography, retrograde pouchgram, or postmortem physical calibration of the anastomotic sites. Histologic examination confirmed excellent healing without obvious fibrosis. CONCLUSION: Laparoscopic construction of an orthotopic neobladder is feasible. The anatomic and functional outcome is excellent and comparable to that of open surgery. Clinical application is imminent.

Laparoscopic renal cryoablation in 32 patients.

OBJECTIVES: Laparoscopic renal cryoablation is a developmental minimally invasive nephron-sparing treatment alternative for highly select patients with small renal tumors. We present our evolving experience with this procedure. METHODS: Thirty-two patients (34 tumors) with a mean tumor size of 2.3 cm on preoperative computed tomography underwent laparoscopic renal cryoablation. As dictated by the tumor location, cryoablation was performed by either the retroperitoneal (n = 22) or the transperitoneal (n = 10) laparoscopic approach using real-time ultrasound monitoring. A double freeze-thaw cycle was routinely performed. RESULTS: The mean surgical time was 2.9 hours, cryoablation time 15.1 minutes, and blood loss 66.8 mL. For a mean intraoperative ultrasonographic tumor size of 2 cm, the mean cryolesion size was 3.2 cm. The hospital stay was less than 23 hours in 22 (69%) of 32 patients. Sequential magnetic resonance imaging scans demonstrated a gradual contraction in the mean diameter of the cryolesions. Of the 20 patients who underwent a 1-year follow-up magnetic resonance imaging scan, the cryoablated tumor was no longer visible in 5. Of note, 23 patients have now undergone a 3 to 6-month follow-up computed tomography-directed biopsy of the cryoablated tumor site; the biopsy was negative for cancer in all 23 patients. No evidence of local or port-site recurrence was found during a mean follow-up of 16.2 months. CONCLUSIONS: Critical long-term data regarding laparoscopic renal cryoablation, a developmental technique, are awaited. However, our initial experience is cautiously optimistic. Despite its significant potential for false-negative results, it is encouraging that the follow-up computed tomography-directed needle biopsies at 3 to 6 months were negative for cancer in 23 of 23 patients.

Robotic remote laparoscopic nephrectomy and adrenalectomy: the initial experience.

PURPOSE: We evaluated the feasibility of performing laparoscopic nephrectomy and adrenalectomy exclusively by using robotic telepresent technology from a remote workstation and compared outcomes with those of conventional laparoscopy in an acute porcine model. MATERIALS AND METHODS: Five pigs underwent bilateral laparoscopic nephrectomy (robotic in 5 and conventional in 4) and adrenalectomy (robotic in 4 and conventional in 3). In the 9 robotic laparoscopic procedures all intraoperative manipulations were completely performed telerobotically from a remote workstation without any conventional laparoscopic assistance on site. Animals were sacrificed acutely. RESULTS: Robotic laparoscopic nephrectomy required significantly longer total operative (85.2 versus 38.5 minutes, p = 0.0009) and actual surgical (73.4 versus 27.5 minutes, p = 0.0002) time than conventional laparoscopy. However, blood loss and adequacy of surgical dissection were comparable in the 2 groups. Robotic laparoscopic adrenalectomy required longer total operative (51 versus 32.3 minutes, p = 0.13) and actual surgical (38.5 versus 18.7 minutes, p = 0.14) time than conventional laparoscopy. The solitary complication in this study was an inferior vena caval tear during robotic right adrenalectomy, which was adequately repaired by sutures telerobotically in a remote manner. CONCLUSIONS: To our knowledge we present the initial experience with remote telerobotic laparoscopic nephrectomy and adrenalectomy. Telepresent laparoscopic surgery is feasible.

Laparoscopic radical nephroureterectomy for upper tract transitional cell carcinoma: the Cleveland Clinic experience.

PURPOSE: We report our single institutional experience with retroperitoneal laparoscopic radical nephroureterectomy in patients with upper tract transitional cell carcinoma and compare results to those achieved by the open technique. MATERIALS AND METHODS: A total of 77 patients underwent radical nephroureterectomy for pathologically confirmed upper tract transitional cell carcinoma. Of these patients 42 underwent laparoscopic nephroureterectomy from September 1997 through January 2000 and 35 underwent open surgery. All specimens were extracted intact. Of the laparoscopic group the juxtavesical ureter and bladder cuff were excised by our novel transvesical needlescopic technique in 27 and radical nephrectomy was performed retroperitoneoscopically in all 42. Data were compared retrospectively with 35 patients undergoing open radical nephroureterectomy from February 1991 through December 1999. RESULTS: Laparoscopy was superior in regard to surgical time (3.7 versus 4.7 hours, p = 0.003), blood loss (242 versus 696 cc, p <0. 0001), specimen weight (559 versus 388 gm., p = 0.04), resumption of oral intake (1.6 versus 3.2 days, p = 0.0004), narcotic analgesia requirements (26 versus 228 mg., p <0.0001), hospital stay (2.3 versus 6.6 days, p <0.0001), normal activities (4.7 versus 8.2 weeks, p = 0.002) and convalescence (8 versus 14.1 weeks, p = 0.007). Complications occurred in 5 patients (12%) in the laparoscopic group, including open conversions in 2, and in 10 (29%) in the open group (p = 0.07). Followup was shorter in the laparoscopic group (11.1 versus 34.4 months, p <0.0001). The 2 groups were similar in regard to bladder recurrence (23% versus 37%, p = 0.42), local retroperitoneal or port site recurrence (0% versus 0%) and metastatic disease (8.6% versus 13%, p = 1.00). Mortality occurred in 2 patients (6%) in the laparoscopic group and 9 (30%) in the open group. Cancer specific survival (97% versus 87%) and crude survival (97% versus 94%) were similar between both groups (p = 0.59). CONCLUSIONS: In patients with upper tract transitional cell carcinoma who are candidates for radical nephroureterectomy the retroperitoneal laparoscopic approach satisfactorily duplicates established technical principles of traditional open oncological surgery, while significantly decreasing morbidity from this major procedure. Short-term oncological and survival data of the laparoscopic technique are comparable to open surgery. Although long-term followup data are not yet available, it appears that laparoscopic radical nephroureterectomy may supplant open surgery as the standard of care in patients with muscle invasive or high grade upper tract transitional cell carcinoma.

Pheochromocytoma coexisting with renal artery lesions.

PURPOSE: Physiologically significant renal artery lesions in the presence of a pheochromocytoma comprise a confounding factor which may impact on the hypertension cure following excision of the pheochromocytoma. We present 10 cases of these dual lesions and review the literature on this entity. MATERIALS AND METHODS: From 1952 to 1999, 269 patients were diagnosed with pheochromocytoma at our institution. Hospital charts of these patients were reviewed retrospectively to identify those with coexisting renal artery stenosis. A Medline search was performed to review the available literature. RESULTS: Of the 269 patients with pheochromocytoma 10 (3. 7%) had coexisting renal artery lesions, including renal artery stenosis in 8, renal artery aneurysm in 1 and postangiographic dissection occlusion in 1. Pheochromocytoma was adrenal in 8 cases and ectopic in 2. Of the patients 9 have been treated to date by adrenalectomy in 4, nephroadrenalectomy in 3, adrenalectomy plus lysis of renal artery adhesions in 1 and adrenalectomy plus renal autotransplantation with bench repair in 1. Both lesions were diagnosed preoperatively in 9 cases and a hypovascular adrenal lesion was missed preoperatively in 1. A review of literature revealed a total of 87 cases of coexisting pheochromocytoma and renal artery lesions. CONCLUSIONS: There are multiple mechanisms that can lead to renal artery stenosis and pheochromocytoma. A high index of suspicion is necessary to enable both entities to be diagnosed preoperatively and allow proper planning of surgical therapy. Incomplete diagnosis may lead to persistent hypertension postoperatively.

Laparoscopic radical cystoprostatectomy with ileal conduit performed completely intracorporeally: the initial 2 cases.

OBJECTIVES: To present the initial 2 patients who underwent laparoscopic radical cystoprostatectomy, bilateral pelvic lymphadenectomy, and ileal conduit urinary diversion, with the entire procedure performed exclusively by intracorporeal laparoscopic techniques. METHODS: Two male patients, 78 and 70 years old, with muscle-invasive, organ-confined, transitional cell carcinoma of the urinary bladder underwent the procedure. The entire procedure, including radical cystoprostatectomy, pelvic node dissection, isolation of the ileal loop, restoration of bowel continuity with stapled side-to-side ileoileal anastomosis, retroperitoneal transfer of the left ureter to the right side, and bilateral stented ileoureteral anastomoses were all performed exclusively by intracorporeal laparoscopic techniques. Free-hand laparoscopic suturing and in situ knot-tying techniques were used exclusively. RESULTS: The surgical time was 11.5 hours in the first patient and 10 hours in the second. The respective blood loss was 1200 mL and 1000 mL. In both patients, ambulation resumed on postoperative day 2, bowel sounds on day 3, and oral intake on day 4; the hospital stay was 6 days. Narcotic analgesia comprised 108.3 mg and 16.5 mg of morphine sulfate equivalent, respectively. Pathologic examination revealed pT4N0M0 (prostate) and pT2bN0M0 transitional cell carcinoma of the bladder with the surgical margins negative for cancer in both patients. No intraoperative or postoperative complications occurred in either patient. CONCLUSIONS: To our knowledge, this is the initial report of laparoscopic radical cystoprostatectomy with intracorporeal ileal conduit urinary diversion. We believe that with further experience and refinement in the operative technique, laparoscopic radical cystoprostatectomy with ileal conduit urinary diversion may become an attractive treatment option for selected candidates with localized muscle-invasive bladder cancer.

Thoracoscopic transdiaphragmatic nephrectomy: feasibility study.

OBJECTIVES: Large-sized upper pole renal or adrenal tumors are often excised by the open thoracoabdominal approach. As an adjunct to existing transperitoneal and retroperitoneal laparoscopic approaches, we explore a novel minimally invasive technique, the thoracoscopic transdiaphragmatic approach, for performing nephrectomy. METHODS: Thoracoscopic transdiaphragmatic nephrectomy was performed bilaterally in 4 farm pigs (8 kidneys) using three ports placed intercostally. RESULTS: The mean surgical time was 69.3 minutes on the left side and 74.3 minutes on the right. Blood loss was 18.7 mL. The mean size of the diaphragmatic incision was 7.2 cm. Adequate retraction of the spleen and liver was feasible during left and right-sided nephrectomy, respectively. Excellent and expeditious access to the renal hilum was routinely obtained. In 5 of 8 procedures, the diaphragmatic incision was located peripherally along the posterior margin; difficulty in suture repair of the diaphragmatic incision was noted in each instance because of the thin diaphragm in this location. During porcine left nephrectomy with ipsilateral lung collapse (n = 4), arterial blood gases and end-tidal carbon dioxide remained normal. CONCLUSIONS: Thoracoscopic transdiaphragmatic nephrectomy is feasible. This technique provides excellent and unique visualization of the renal vessels and the upper pole of the kidney and adrenal gland. When indicated, the thoracoscopic transdiaphragmatic approach, used in combination with current laparoscopic techniques, has the potential to provide the minimally invasive counterpart of the thoracoabdominal surgical approach in select patients with upper pole renal or adrenal pathologic findings.

Laparoscopic enterocystoplasty.

OBJECTIVES: To report the initial clinical experience with laparoscopic augmentation enterocystoplasty using the ileum, sigmoid, or right colon. METHODS: Three patients with functionally reduced bladder capacities due to neurogenic causes underwent laparoscopic enterocystoplasty: ileocystoplasty (n = 1), sigmoidocystoplasty (n = 1), and cystoplasty with cecum and proximal ascending colon (n = 1). In the last patient, a continent, catheterizable, ileal conduit with an umbilical stoma was also created. In all patients, bowel reanastomosis was performed by exteriorizing the bowel loop outside the abdomen through a 2-cm extension of the umbilical port site. Creation of a large cystotomy, mobilization of the appropriate bowel segment, and the circumferential enterovesical anastomosis were all performed intracorporeally by laparoscopic techniques. RESULTS: The operative times were 5.3, 8, and 7 hours. All three laparoscopic enterovesical anastomoses were watertight, without postoperative urinary extravasation. The hospital stay was 7, 5, and 4 days. CONCLUSIONS: Laparoscopic enterocystoplasty is feasible, safe, and efficacious and appears to be an attractive alternative to open enterocystoplasty. Various bowel segments can be used as with open surgery, including creation of a continent, catheterizable stoma. Although further technical refinements will undoubtedly occur, even at this early stage, it is clear that the technical steps of an enterocystoplasty can be satisfactorily and effectively performed laparoscopically.

Retroperitoneal minilaparoscopic nephrectomy in the rat model.

OBJECTIVES: Development of small animal models for laparoscopic surgery is important for basic pathophysiologic and oncologic studies, instrument development, and surgical training. Although transperitoneal laparoscopy has been described in the rat, the technical feasibility of the retroperitoneoscopic approach for major renal surgery has not been reported previously. Herein, we describe the development of a rat model for retroperitoneal minilaparoscopic nephrectomy. METHODS: Sixteen male Sprague-Dawley rats underwent a three-port bilateral retroperitoneoscopic nephrectomy using 2 and 3-mm instruments and optics exclusively. After developing the technique in 10 animals, the study was conducted in 6 animals. Following retroperitoneal balloon dilation and CO(2) pneumoretroperitoneum (mean 4.5 mm Hg), nephrectomy was accomplished by intracorporeal en bloc ligation of the renal pedicle. To prevent peritoneal entry, the anterior surface of the kidney was mobilized subcapsularly. Volume of the created retroperitoneal space and peritoneal integrity were confirmed by a contrast x-ray study. Intraperitoneal pressure was monitored constantly during the procedure. RESULTS: Mean surgical time was 74.5 minutes (range 60 to 95) and estimated blood loss was less than 1 mL. Mean volume of the retroperitoneal space was 8.4 mL after initial balloon dilation, and 11.5 mL after nephrectomy. Mean weight of the excised kidneys was 1. 4 g. Inadvertent peritoneotomy occurred during 3 of 12 study nephrectomies. Complications included renal artery hemorrhage leading to death in 1 animal and renal vein injury in 1 animal. CONCLUSIONS: Laparoscopic retroperitoneal nephrectomy in the rat model is technically feasible. This novel small animal model can be used for further studies of the retroperitoneal laparoscopic approach.