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Renal tumor classification is important because histopathological subtypes are associated with distinct clinical behavior. However, diagnosis is difficult because tumor subtypes have overlapping microscopic characteristics. Therefore, ancillary methods are needed to optimize classification. We used oligonucleotide microarrays to analyze 31 adult renal tumors, including clear cell renal cell carcinoma (RCC), papillary RCC, chromophobe RCC, oncocytoma, and angiomyolipoma. Expression profiles correlated with histopathology; unsupervised algorithms clustered 30 of 31 tumors according to appropriate diagnostic subtypes while supervised analyses identified significant, subtype-specific expression markers. Clear cell RCC overexpressed proximal nephron, angiogenic, and immune response genes, chromophobe RCC oncocytoma overexpressed distal nephron and oxidative phosphorylation genes, papillary RCC overexpressed serine protease inhibitors, and extracellular matrix products, and angiomyolipoma overexpressed muscle developmental, lipid biosynthetic, melanocytic, and distinct angiogenic factors. Quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry of formalin-fixed renal tumors confirmed overexpression of proximal nephron markers (megalin/low-density lipoprotein-related protein 2, alpha-methylacyl CoA racemase) in clear cell and papillary RCC and distal nephron markers (beta-defensin 1, claudin 7) in chromophobe RCC/oncocytoma. In summary, renal tumor subtypes were classified by distinct gene expression profiles, illustrating tumor pathobiology and translating into novel molecular bioassays using fixed tissue.

Purpose: Training on a virtual reality (VR) simulator has been shown to improve the performance of VR endoscopic tasks by novice endoscopists. However, to our knowledge the translation of VR skills into clinical endoscopic proficiency has not been demonstrated. We established criterion validity for a VR ureteroscopy simulator by evaluating VR trained subjects in a cadaver model., Materials and Methods: A total of 32 participants, including 16 medical students and 16 urology residents, were evaluated at baseline on a VR ureteroscopy simulator (Uromentor, Simbionix, Lod, Israel), performing simple diagnostic ureteroscopy. The students then underwent 5 hours of supervised training on the simulator. Two weeks later all participants were reevaluated (VR2) on the simulator when repeating the initial task. Each participant was then assessed on the performance of a similar diagnostic ureteroscopy in a male cadaver., Results: In medical students VR2 and cadaver performances correlated closely for several measured parameters (total time for task completion and overall global ratings score). In contrast, there was little correlation between the 2 performances in residents. Indeed, performance on the cadaver correlated more closely with the training level than VR2 scores. Despite VR training medical students were unable to perform cadaver ureteroscopy comparably to residents., Conclusions: For novice endoscopists performance on the simulator after training predicted operative (cadaver) performance and, thus, it may be useful for the education and assessment of physicians in training. However, VR training is unable to override the impact of clinical training, although it may help shorten the learning curve early in training.

Purpose: Radio frequency ablation (RFA) of renal tumors is a relatively new technology. Few groups are familiar with the posttreatment appearance of these lesions and how they differ from cryoablated renal masses. We describe the evolution of the appearance of these lesions on followup contrast enhanced (CE) computerized tomography (CT)., Methods and Materials: A total of 64 consecutive renal tumors treated with RFA from April 2000 to September 2003 for which posttreatment CE-CT was done were included in this study. CE-CT was reviewed at 6 weeks, 3 months, 6 months and every 6 months thereafter to determine the characteristic features and evolution of these lesions., Results: Renal tumors were treated with CT guided percutaneous (34), laparoscopic (28) or open (2) RFA. At a median followup of 13.7 months (range 6 weeks to 29 months) 62 RFA lesions demonstrated an absence of contrast enhancement on CE-CT. Treated endophytic tumors developed a low density, nonenhancing, wedge-shaped defect with fat infiltration seen between the ablated tissue and normal parenchyma. Treated exophytic tumors retained a configuration similar to that of the original with a lack of contrast enhancement and minimal shrinkage. Percutaneous treated lesions developed a peritumor scar or halo that demarcated ablated and nonablated tissue (perirenal fat). Persistent tumor was marked by contrast enhancement within the ablation borders of the original mass in 1 case, whereas tumor recurred after initial successful ablation with an enhancing nodule in 1., Conclusions: The radiographic features and evolution of radio frequency ablated renal tumors are unique. Successfully treated tumors demonstrated no contrast enhancement, minimal shrinkage and occasional retraction from normal parenchyma by fat infiltration.

Purpose: Small-intestinal submucosa (SIS) has been successful as an onlay graft in ureteral repair, but tubularized segment interposition of SIS has been unsuccessful. Our objective was to evaluate whether a type I collagen inhibitor, halofuginone, would prevent stricture formation in tubularized SIS interposition., Materials and Methods: We performed either laparoscopic partial ureteral excision followed by an SIS onlay graft (N = 5) or complete laparoscopic ureteral excision followed by an SIS interposition graft (N = 7) in domestic pigs. Animals received either no (N = 3), low-dose (N = 5), or high-dose (N = 4) halofuginone. Animals had ureteral stenting for 2 weeks after surgery and were permitted to survive for 6 or 9 weeks. An intravenous urogram (IVU) was performed prior to sacrifice. Kidneys were examined grossly and histologically., Results: One animal that received an onlay graft died of an unrelated illness. The remaining four ureteral onlay animals, including one control and two low-dose and one high-dose pig, had grossly normal kidneys at harvest. The IVU was normal in the control and high-dose animal but showed delayed excretion with mild hydroureteronephrosis in the low-dose animals. Pathologic examination of the SIS site revealed circumferential reepithelialization with inflammation and mild fibrosis. All seven tubularized interposition graft kidneys demonstrated either severe hydroureteronephrosis (N = 5) or renal atrophy (N = 2), and all had complete obstruction on IVU. Pathologic examination revealed a stenotic ureteral lumen with extensive surrounding inflammation and fibrosis., Conclusions: An SIS onlay graft was successful in the porcine model of ureteral injury. Halofuginone, a type I collagen inhibitor, did not demonstrate a significant beneficial effect in this technique. Ureteral tubularized interpositions with SIS are unsuccessful and not improved by halofuginone.

Purpose: Regardless of training, innate ability may influence the acquisition of endoscopic skills. Until recently objective methods to assess innate ability have not been available. We compared objective measures of human basic performance resources (BPRs) using nonlinear causal resource analysis (NCRA) and expert rated endoscopic performance of medical students on a virtual reality (VR) simulator., Materials and Methods: BPRs were measured in 18 medical students (group 1) using 13 validated tests. BPR results were compared to the results of ureteroscopic skills assessment on the VR simulator. An NCRA model was devised to predict performance based on BPRs and the limiting performance resource (LPR). The same BPRs were measured in a second group of 14 medical students (group 2). Using the model created from group 1 performance of VR ureterorenoscopy was predicted based on LPR for each student in group 2. Predicted performance was compared to rated performance., Results: The average difference in score between 2 expert raters was 7.2%. The average difference in predicted score based on the NCRA model and rated score was only 8.0%. In 9 of the 14 group 2 subjects (63%) the performance prediction by NCRA was in excellent agreement (+/-10%) with the expert rating on the VR simulation. NCRA over predicted performance in 2 subjects (14%) and under predicted performance in 3 (21%)., Conclusions: Objective prediction of ureteroscopic performance in the VR environment using LPRs (measures of innate ability) for each subject is possible and practical using new measurement and modeling methods. The selection of surgical candidates, training and the educational curriculum could be impacted.

Purpose: Virtual reality surgical simulators may shorten operative time and reduce the potential for iatrogenic injury by providing training outside the operating room. We hypothesized that training on a virtual ureteroscopy (VU) simulator would allow novice endoscopists to overcome the initial learning curve before entering the operating room., Materials and Methods: We evaluated 16 medical students on their ability to perform specific ureteroscopic tasks on a VU simulator. The students trained on the simulator for a total of 5 hours over multiple sessions using different training modules and then were retested on the initial module. Likewise, 16 urology residents with varying degrees of endoscopic experience were assessed on the same test module twice, without additional simulator training., Results: The students improved task completion time from 17.4 to 8.7 minutes (p <0.05), while the residents performed the task in 7.6 minutes at baseline and 6.7 minutes at the second trial. Stratification of residents by years of urology training revealed that the mean completion time for the students after training did not differ statistically from that of first year residents who had performed a median of 14 clinical ureteroscopies. Furthermore, the subjective performance scores of the students were comparable to those of the first year residents., Conclusions: Novice medical students trained on a VU simulator improved task completion time by 50% after training, and performed comparably to residents who had completed nearly 1 year of urology training. VR training may allow beginning urology residents to shorten the initial learning curve associated with ureteroscopy training, although this hypothesis requires further validation.

Objectives: Hydropneumothorax (HPTX) is recognized as a potential complication of percutaneous nephrostolithotomy (PCNL), particularly with supracostal access. Postoperative chest radiography (CXR) is routinely used to evaluate the chest after PCNL. We prospectively compared the sensitivity of intraoperative chest fluoroscopy with immediate postoperative portable CXR and postoperative day 1 chest computed tomography (CT) for the detection of pleural fluid., Methods: A total of 89 consecutive patients (mean age 47.9 +/- 13.3 years; 100 renal units) undergoing PCNL were prospectively evaluated with intraoperative fluoroscopy at the conclusion of the procedure and then with anteroposterior CXR in the postanesthesia care unit and postoperative day 1 noncontrast, thin-cut CT of the kidneys and lung bases. CT imaging of the lung bases comprised the reference standard for detecting pleural fluid., Results: A total of 104 percutaneous renal accesses in 100 renal units, 60 above and 44 below the 12th rib, were used. In 16 cases (16%), a second-stage procedure was performed to clear residual stone fragments detected on post-PCNL CT. HPTX was detected in 1, 8, and 38 cases by initial fluoroscopy, immediate postoperative CXR, and CT scan, respectively. Intervention was necessary in 7 patients. In 2 patients with fluoroscopic evidence of pleural fluid (1 at the initial PCNL and 1 during second-look flexible nephroscopy), intraoperative pleural drainage was performed percutaneously. In the other 5 patients, intervention was determined by the size of the HPTX on chest CT scan (n = 1) or the presence of symptoms (n = 4). In no case was intervention performed on the basis of the immediate postoperative CXR findings when intraoperative chest fluoroscopy was negative., Conclusions: Intraoperative chest fluoroscopy during PCNL is sufficient to detect clinically significant HPTXs, and, therefore, routine postoperative CXRs are not necessary. However, a high index of suspicion based on clinical symptoms postoperatively should prompt chest imaging.

Background: Diffuse superficial transitional-cell carcinoma (TCC) refractory to standard therapies poses a clinical dilemma. Photodynamic therapy (PDT), which uses an interaction between absorbed light and a retained photosensitizing agent to destroy tissue, has been used to treat diffuse superficial bladder TCC, although there are few reports of long-term outcomes., Patients and Methods: A series of 34 patients, 29 with TCC carcinoma in situ (CIS) and 5 with multiple small papillary stage T(a) or T(1) lesions, received porfimer sodium (P) 48 hours before whole-bladder PDT with 630-nm laser light. A 0.02% soybean emulsion diffusion medium was instilled into the bladder, and the laser optical fiber was positioned under triplanar sonography prior to PDT. The mean follow-up was 52 months., Results: At 3 months, a complete response (CR) in 14 (44%) of the 32 evaluable patients, a partial response (PR) in 4 (12%), and no response (NR) in 14 (44%). Four of the five patients with extensive papillary lesions did not respond. The NR rate for patients with CIS with or without resected papillary lesions was 37%. The mean time to recurrence in the CR group was 9.8 months, and five members of this group (36%) underwent cystectomy (mean time 20 months) for persistent/progressive disease (N = 3) or bladder contracture (N = 2). In the NR group, 6 (43%) underwent cystectomy (mean time 14 months) for persistent/progressive disease. Metastatic bladder cancer was the cause of death in only 4 of the 12 patients who have died. Of the remaining 22 patients, 15 are still alive and have an intact bladder, nine with no disease and six with only superficial disease., Conclusion: This is the first report of long-term results following whole-bladder PDT using diffusion medium for isotropic light distribution. More than half of the patients with TCC refractory to traditional intravesical therapy received benefit from a single PDT session. Patients with extensive flat papillary lesions do not appear to respond well. Patients who achieve a CR have less likelihood of and longer time interval before needing cystectomy for progressive disease than NR patients. Our PDT protocol is associated with minimal morbidity in these high-risk patients.

Background: Interest in laparoscopic surgery has prompted development of educational programs designed to teach and assess laparoscopic skills. Although these programs are beneficial, because of the inherent demands imposed by laparoscopy some aspects of operative performance might not improve with practice. This suggests that innate ability could predict level of operative skill. Assessment of operative and technical potential to date has relied largely on subjective rather than objective criteria. In this study, the relationships between objective measures of human basic performance resources (BPRs) and laparoscopic performance were evaluated using Nonlinear Causal Resource Analysis (NCRA), a novel predictive and explanatory modeling approach based on General Systems Performance Theory., Study Design: Twenty urology residents were voluntary enrolled. Thirteen validated BPRs were measured and analyzed relative to operative laparoscopic performance (assessed by two experts) of two porcine laparoscopic nephrectomies (LN). The laparoscopic procedure, representing a High Level Task (HLT), was evaluated using a modified Global Rating of Operative Performance Scale. NCRA models were devised to predict performance of the HLT laparoscopic nephrectomies based on BPRs and to determine the limiting performance resource., Results: NCRA models predicted excellent agreement with actual operative performance, suggesting that measures of innate ability (or BPRs) predicted performance of laparoscopic nephrectomy. In 65%, the prediction by NCRA was near identical to the expert rating on the HLT. In 25% of cases, NCRA overpredicted performance; in 10%, NCRA underpredicted performance of the HLT compared to the subjective ratings. Neuromotor channel capacity was the most common performance-limiting resource., Conclusions: Preliminary findings suggest objective prediction of laparoscopic performance with limiting resource diagnostics for an individual surgeon is possible and practical using appropriate new measurement and modeling methods. Selection of surgical candidates, training, and educational curriculum could be positively affected.

Little information is available concerning the morbidity of radiofrequency ablation (RFA) or the evolution of an RFA lesion over time. We report our findings in a kidney removed 1 year after RFA of a 2.3-cm renal tumor. After RFA, the patient experienced flank pain, followed by hydronephrosis, ureteropelvic junction obstruction, and eventual loss of function in the treated kidney. Nephrectomy revealed no residual renal cell carcinoma. RFA can completely destroy renal cell carcinoma in situ without histologic evidence of persistence or recurrence for up to 1 year after treatment. Care must be taken to avoid concurrent damage to the collecting system.

Laparoscopic radical nephrectomy has evolved tremendously over the past decade to the point where it should be considered the standard of care for localized renal tumors not amenable to nephron-sparing surgery. The benefits of decreased postoperative pain, shortened hospital stay, quicker convalescence, and improved cosmesis have been proved in numerous studies. Long-term oncologic results of LRN have demonstrated equivalent outcomes to ORN.

Objectives: The primary disadvantage of renal tumor RF ablation is the inability to monitor the intraoperative propagation of the RF lesion with real-time imaging. We sought to assess whether adequately lethal temperatures are obtained at the margins of the intended ablation zone using laparoscopic thermography to monitor radiofrequency (RF) lesions in real time, thermocouple measurements, and histopathologic evaluation., Methods: Renal RF lesions were created under direct laparoscopic vision in the upper (1 cm diameter) and lower (2 cm) poles of the right kidney in 5 female pigs. The RF lesions were produced with the RITA generator and probe, set at 105 degrees C for 5-minute ablations. During RF treatment, a laparoscopic infrared (IR) camera measured the surface parenchymal temperatures, as did multiple thermocouples. The pigs were then either immediately killed (n = 3) or allowed to live for 2 weeks (n = 2). The kidneys were removed to correlate the temperature measurements with histologic analysis of the ablated lesion., Results: Using a threshold temperature of greater than 70 degrees C for visual "temperature" color change, the IR camera identified the region of pathologic necrosis of the renal parenchyma during RF ablation. Thermocouple measurements demonstrated that the temperatures at the intended ablation radius reached 77.5 degrees C at the renal surface and 83.7 degrees C centrally, and temperatures 5 mm beyond the set radius reached 52.6 degrees C at the surface and 47.7 degrees C centrally. The average diameter of the gross lesion on the surface of the kidney measured 17.1 mm and 22.4 mm for 1-cm and 2-cm ablations, respectively. These surface measurements correlated with an average diameter of 16.1 mm and 15.9 mm (1-cm and 2-cm ablations, respectively) as measured with the IR camera. All cells within these ablation zones were nonviable by nicotinamide adenine dinucleotide diaphorase analysis. The average depth of the lesions measured 19 mm (1-cm ablation) and 25 mm (2-cm ablation) on gross histologic examination., Conclusions: The laparoscopic IR camera is able to monitor the surface renal temperatures during RF treatment. Thermocouple measurements during RF ablation confirmed the thermographic findings and demonstrated that lethal temperatures at the margin of the intended treatment zone are routinely obtained and that a rapid decline in temperature occurs beyond the predicted ablation margin.

Background and Purpose: Widespread application of laparoscopic partial nephrectomy has been limited by the lack of a reliable means of attaining hemostasis. We describe laser tissue welding using human albumin as a solder to control bleeding and seal the collecting system during laparoscopic heminephrectomy in a porcine model., Materials and Methods: Laparoscopic left lower-pole heminephrectomy was performed in five female domestic pigs after occluding the hilar vessels. Using an 810-nm pulsed diode laser (20 W), a 50% liquid albumin-indocyanine green solder was welded to the cut edge of the renal parenchyma to seal the collecting system and achieve hemostasis. Two weeks later, an identical procedure was performed on the right kidney, after which, the animals were sacrificed and both kidneys were harvested for ex vivo retrograde pyelograms and histopathologic analysis., Results: All 10 heminephrectomies were performed without complication. The mean operative time was 82 minutes, with an average blood loss of 43.5 mL per procedure. The mean warm ischemia time was 11.7 minutes. For each heminephrectomy, a mean of 4.2 mL of solder was welded to the cut parenchymal surface. In three of the five acute kidneys and all five 2-week kidneys, ex vivo retrograde pyelograms demonstrated no extravasation. In addition, no animal had clinical evidence of urinoma or delayed hemorrhage. Histopathologic analysis showed preservation of the renal parenchyma immediately beneath the solder., Discussion: Laser tissue welding provided reliable hemostasis and closure of the collecting system while protecting the underlying parenchyma from the deleterious effect of the laser during porcine laparoscopic heminephrectomy.

Purpose: To develop a technique for laparoscopic partial nephrectomy (LPN) without the use of hilar occlusion that allows large renal resection and excellent hemostasis., Materials and Methods: Five female domestic pigs underwent right laparoscopic transperitoneal lower-pole partial nephrectomy after placement of pledgeted parenchymal compression sutures tied intracorporeally to induce regional renal hypoperfusion. Postoperatively, serial serum creatinine measurements were obtained to monitor renal function. The pigs were allowed to recover and 2 weeks later underwent an identical procedure on the left side. The animals were sacrificed after the second procedure, and both renal units were removed for ex vivo retrograde urograms and histologic analysis., Results: The median operative time was 154.5 minutes (range 110-305 minutes), and the median blood loss was 137.5 mL (range 100-300 mL). On average, 35% (range 31%-36.8%) of the kidney was resected. All cases required use of adjunctive hemostatic clips to control bleeding from central vessels. All animals survived 2 weeks and had no evidence of urinary extravasation clinically or on ex vivo retrograde urograms., Conclusions: In the porcine model, LPN with placement of pledgeted sutures allows resection of large renal segments, although technical refinements are required to improve hemostasis. Currently, the need for adjunctive hemostatic measures limits the initial clinical application of this technique to small, exophytic tumors.

Purpose: To our knowledge we present the initial series of renal mass in situ laparoscopic radio frequency ablation. We also discuss the indications for and results of subsequent laparoscopic partial nephrectomy., Materials and Methods: Laparoscopic radio frequency ablation was performed in 13 patients with a mean age of 59 years (range 18 to 81) and a total of 17 small enhancing renal masses. In 5 patients the tumor was subsequently excised completely, whereas in 7 it was left in situ after treatment. In 1 patient with 5 lesions only the largest lesion was excised, while the other 4 were left in situ., Results: Mean tumor size was 1.96 cm. (range 0.9 to 3.6). Tumors that remained in situ tended to be endophytic and located in the mid pole. Pathological analysis revealed renal cell carcinoma in 10 patients, angiomyolipoma in 2 and oncocytoma in the patient with multiple lesions. None of the 8 patients with renal cell carcinoma who had at least 6 weeks of followup (mean 9.8 months, range 1.5 to 22) had any evidence of persistent tumor enhancement on surveillance computerized tomography or any other evidence of disease progression. There was 1 focal positive margin in a patient who underwent radio frequency ablation and excision of renal cell carcinoma but the patient remained disease-free 1 year after treatment., Conclusions: Early experience with laparoscopic radio frequency ablation in situ or combined with partial nephrectomy shows that it appears to be a safe method of managing small enhancing renal masses. Radio frequency assisted laparoscopic partial nephrectomy is reserved for easily accessible exophytic tumors, while strict surveillance is required for lesions remaining in situ after ablation. Additional followup is required to assess long-term effectiveness.

Objectives: To evaluate our evolving experience with percutaneous radiofrequency (RF) renal tumor ablation and focus on our technique to ensure maximal treatment efficacy and reduce the possibility of complications., Methods: Fifteen patients with small (less than 4 cm) posterior or lateral contrast-enhancing (more than 10 Hounsfield units) renal tumors were candidates for RF treatment. Of these patients, 12 (13 tumors) received computed tomography-guided percutaneous RF ablation. General anesthesia was administered in all but our first 2 patients, who received intravenous sedation. After treatment, patients were closely followed up with computed tomography scans at 6 weeks and 3, 6, and 12 months, and every 6 months thereafter. Successful ablation was defined as a lesion along with a margin of normal parenchyma that no longer enhanced (less than 10 Hounsfield units) on follow-up contrast imaging., Results: The mean tumor size was 2.4 +/- 0.6 cm. The average procedure time was 95 minutes (range 60 to 150) and length of stay 0.9 days. All patients underwent the procedure without any major complications. At a mean follow-up of 4.9 months, 12 (93%) of 13 tumors were successfully ablated. In 3 patients, the procedure was not performed because of intervening bowel or lung parenchyma when positioned in the prone position before the procedure. Computed tomography-guided percutaneous RF ablation of small renal tumors is a viable minimally invasive treatment option with a high short-term success rate and low morbidity. This new technology must be uniformly applied to assess its long-term efficacy.

Purpose: To develop a safe and effective technique for laparoscopic partial nephrectomy without need for hilar occlusion., Materials and Methods: Laparoscopic transperitoneal lower-pole partial nephrectomy was performed in five 45- to 50-kg female farm pigs using a 980-nm diode laser. Standard transperitoneal access was obtained, and a four-port approach was used to perform a laparoscopic right partial nephrectomy using a diode laser (23 W) without hilar occlusion. The pigs were allowed to recover and 2 weeks later underwent a left laparoscopic partial nephrectomy. Postoperatively, renal function was monitored by serial serum creatinine measurements. Both kidneys and ureters were removed for ex-vivo retrograde pyelograms and histologic analysis., Results: The 980-nm diode laser resulted in successful lower-pole partial nephrectomy without hilar occlusion in all 10 of the kidneys. In three cases, laser hemostasis was insufficient, and adjunctive hemostatic clips were necessary to stop bleeding. The mean operative time was 126 minutes, and the mean laser time was 84 minutes. An average of 23% (range 13%-33%) of the kidney parenchyma was resected. The mean blood loss was 150 mL (range 50-300 mL). There was no evidence of urinary extravasation on ex-vivo retrograde pyelograms at 2 weeks in any of the kidneys., Conclusion: Laparoscopic partial nephrectomy without hilar occlusion using the 980-nm diode laser is feasible in the porcine model. Because adjunctive hemostatic measures may be necessary in some cases, clinical trials in humans should be limited to small exophytic tumors.

Percutaneous supracostal renal puncture provides ideal access to the collecting system or proximal ureter but is associated with an increased risk of pleural injury. We describe a simplified approach to intraoperative thoracostomy tube placement that uses urologic techniques and protects against recurrent hydrothoraces at second-look nephroscopy, without increasing patient morbidity or length of hospital stay.

Background: The objective of this study was to evaluate the effect of supervised training using a state-of-the-art virtual reality (VR) genitourinary endoscopy simulator on the basic endoscopic skills of novice endoscopists., Study Design: We evaluated 21 medical students performing an initial VR case scenario (pretest) requiring rigid cystoscopy, flexible ureteroscopy with laser lithotripsy, and basket retrieval of a proximal ureteral stone. All students were evaluated with objective parameters assessed by the VR simulator and by two experienced evaluators using a global rating scale. Students were then randomized to a control group receiving no further training or a training group, which received five supervised training sessions using the VR simulator. All students were then evaluated again in the same manner using the same case scenario (posttest)., Results: Comparing the results of pre- and posttests, no major differences were demonstrated for any variable in the control group. In the trained group, posttest results revealed statistically significant improvement from baseline in the following parameters: total procedure time (p = 0.002), time to introduce a ureteral guidewire (p = 0.039), self-evaluation (p < 0.001), and evaluator assessment (p < 0.001). Comparing the posttest results of the control and trained arms, we found significantly better posttest scores in the trained group for the following parameters: ability to perform the task (p = 0.035), overall performance (p = 0.004), and total evaluator score (p < or = 0.001)., Conclusions: Students trained on the VR simulator demonstrated statistically significant improvement on repeat testing, but the control group showed no improvement. Endourologic training using VR simulation facilitates performance of basic endourologic tasks and might translate into better performance in the operating room.

The most profound change among the many that have occurred in the management of renal-cell carcinoma (RCC) in recent years is the advent of nephron-sparing surgery for masses <4 cm. The main challenge now is to reduce the morbidity associated with such procedures. Because of the problems in obtaining hemostasis, only a few highly experienced surgeons are performing partial nephrectomy laparoscopically. Numerous techniques and tools have been studied, including laparoscopic duplication of the open operation; hand-assisted surgery; double-loop and cable-tie tourniquets; ultrasonic shears; radiofrequency, microwave, and laser energy; the Endosnare; and hydro-jet dissection. Also, ablation with cold, radiofrequency energy, or high-intensity focused ultrasound is being explored. Just as open surgery for urolithiasis has been all but replaced by extracorporeal lithotripsy and endoscopic techniques, treatment of most RCCs will ultimately shift from open to minimally invasive methods.

Purpose: Laparoscopic retroperitoneal lymph node dissection is significantly less morbid than open retroperitoneal lymph node dissection but it is generally more costly due to longer operative time and disposable equipment. In response to budgetary pressure at our large county hospital we identified the cost components of laparoscopic retroperitoneal lymph node dissection that could be targeted to decrease procedure costs before expanding our laparoscopic retroperitoneal lymph node dissection program., Materials and Methods: A comprehensive literature review of open and laparoscopic retroperitoneal lymph node dissection was performed and certain parameters were abstracted, including operative time and equipment, hospital stay, perioperative complications and surgical success rates. Using these data the projected overall cost and individual cost centers at our institution were compared for open and laparoscopic retroperitoneal lymph node dissection. Decision tree analysis models were devised to estimate the cost of each treatment using commercially available software. We performed 1 and 2-way sensitivity analysis to evaluate the effect of individual treatment variables on overall cost. Base case analysis involved a young man with clinical stage I nonseminomatous testicular cancer who was a candidate for retroperitoneal lymph node dissection., Results: Based on a review of the costs at our institution open retroperitoneal lymph node dissection was a less costly procedure at $7,162 versus $7,804 for the laparoscopic approach. The slight cost superiority of the open approach was due to significantly lower costs associated with operating room time and equipment. On the other hand, the laparoscopic procedure showed a cost advantage for hospital stay. On 1-way sensitivity analysis laparoscopic dissection was less costly when operative time was less than 3.6 hours, hospitalization was less than 2.2 days or laparoscopic equipment costs were less than $768. On 2-way sensitivity analysis the laparoscopic approach was cost advantageous when performed in less than 5 hours or when the patient was discharged home within 2 days postoperatively., Conclusions: The primary cost variables for surgical treatment for testicular cancer include operative time, hospital stay and equipment cost. According to published data and decision tree analysis open retroperitoneal lymph node dissection is slightly less costly (less than $650) than laparoscopic retroperitoneal lymph node dissection for the surgical treatment of clinical stage I nonseminomatous testicular cancer at our institution. Our model identifies several measures that can be applied at any institution to render laparoscopic retroperitoneal lymph node dissection economically superior to the open approach.

Purpose: To report on the technique and utility of the holmium: YAG laser in performing laparoscopic partial nephrectomy (LPN)., Patients and Methods: Three patients with indications for LPN (complex cyst, nonfunctioning lower pole, renal mass) underwent parenchymal-sparing procedures with the Ho:YAG laser. The kidney was identified using a transperitoneal laparoscopic technique. Gerota's fascia was opened, and the renal mass/nonfunctioning lower pole was resected using the laser. Settings of 0.2 J/pulse at 60 pulses/sec and 0.8 J/pulse at 40 pulses/sec were used., Results: All three procedures were performed successfully with minimal blood loss and without the need for hilar occlusion. Although the laser alone was hemostatic, fibrin glue was applied in two cases and oxidized cellulose in one case to reinforce the tissue against delayed bleeding. There were no perioperative complications, and all patients left the hospital within 3 days., Conclusions: At high power settings, the Ho:YAG laser is an effective tool for LPN. It results in good hemostasis without the need for hilar occlusion. This technique promises to facilitate the laparoscopic management of renal tumors and nonfunctioning moieties of duplicated systems.

Purpose: We determined parental preferences for the treatment of vesicoureteral reflux in their child., Materials and Methods: Parents of children with vesicoureteral reflux were prospectively recruited to evaluate choices in reflux management. In each case a standard questionnaire that described the treatment options for reflux was administered. Parents were asked to choose between long-term antibacterial prophylaxis with annual radiography studies and open or endoscopic treatment at each of 1 to 5 years of followup. They were also given the choice between open or endoscopic treatment. Annual resolution and/or correction rates provided for medical, surgical and endoscopic management were 20%, 95% to 100% and 80% after 1 or 2 injections, respectively., Results: We queried 91 families of female (81%) and male (19%) patients. Average duration of reflux followup was 2 years and mean patient age was 49.8 months. At diagnosis reflux was grades I to II in 65% of cases, grade III in 26% and grades IV to V in 9%. The majority of parents chose daily antibiotics over surgery if the child was predicted to have vesicoureteral reflux for 1 to 4 years. However, the majority chose ureteral reimplantation over daily antibiotics and yearly x-ray if a 5-year course was predicted. In contrast, parents chose daily antibiotics rather than endoscopic treatment if the anticipated interval was 1 to 3 years. After 3 years the majority preferred the endoscopic approach. Also, 60% of parents stated that they would choose endoscopic treatment over reimplantation, although the child may require repeat endoscopic treatment and there was a 20% chance of persistent vesicoureteral reflux., Conclusions: Parents of children with vesicoureteral reflux prefer antibiotic prophylaxis as initial treatment. However, when daily antibiotics and yearly cystography may be required beyond 3 to 4 years, most parents would choose definitive correction. While endoscopic treatment is less effective than surgery, parents prefer endoscopic treatment, most likely because it is less invasive. Also, when compared directly against each other, the majority of parents stated that they would choose endoscopic treatment over surgery, although it has a lower success rate.

Purpose: We prospectively compared transvaginal antimicrobial mesh (MycroMesh*) and anterior vaginal wall slings using an outcomes analysis., Materials and Methods: Between August 1997 and November 1998 we implanted transvaginal slings in 40 consecutive women randomized to a synthetic mesh (20) or vaginal wall (20) group. All patients had documented stress urinary incontinence on preoperative urodynamics. We prospectively compared postoperative outcomes data obtained from pelvic examinations, cough stress test, cotton swab test and validated patient questionnaires using a visual analog scale., Results: Complete followup was available in all patients. Mean followup was 22 months (range 12 to 27). Stress incontinence was cured in 95% of the mesh and 70% of the vaginal wall group, and pelvic prolapse was cured in 100% and 95%, respectively. Transient de novo urge incontinence was noted in 12.5% of the mesh and 14.3% of the vaginal wall group. Mean postoperative cotton swab angle during Valsalva's maneuver was 20 and 45 degrees for the mesh and vaginal wall groups, respectively. The incidence of urinary retention and tissue erosion was 0% for both groups. The satisfaction rate was 100% and 80% for the mesh and vaginal wall groups, respectively., Conclusions: The antimicrobial MycroMesh sling was superior to the vaginal wall sling for correction of stress incontinence and pelvic prolapse with comparatively low morbidity.

A sensitive assay was developed for the quantitation of vinblastine, desacetylvinblastine and vincristine using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). Analyses were performed on an Ultrasphere C18 microbore column using ammonium acetate as mobile phase. The calibration curves were linear across the range of 0.51-4.00 ng/ml (0.63-4.93 nM) for vinblastine, 0.74-3.93 ng/ml (0.96-5.11 nM) for desacetylvinblastine and 0.30-3.95 ng/ml (0.36-4.79 nM) for vincristine. Vinca alkaloid concentrations were measured with an accuracy and precision within 11%. This assay could be implemented to determine the plasma concentrations for pharmacokinetic studies of vinblastine, desacetylvinblastine and vincristine in conjunction with clinical trials.