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Percutaneous renal ablation is often performed under conscious sedation and without contrast-enhanced imaging. We evaluated intermediate-term outcomes of patients undergoing percutaneous contrast-enhanced computed tomography (CT)-guided radiofrequency ablation (RFA) under general anesthesia (GA) at two high-volume centers.Prospectively maintained Institutional Regulatory Board-approved databases were searched to identify patients treated with percutaneous RFA using contrast-enhanced CT under GA. A total of 163 masses in 151 patients were treated. Enhancement on imaging or a positive biopsy at 4 to 6 weeks was considered incomplete ablation. Positive findings beyond this interval were defined as local recurrence.The median follow-up was 18 months (range, 1.5-70). Median tumor size was 2.3 cm (range, 1-5.4). Of the 130 (80%) masses with definitive pathology, 70% were renal cell cancer. Five masses had evidence of viable tumor at 4 to 6 weeks posttreatment for a complete initial ablation rate of 97%. Three of these five lesions were endophytic. Five masses (3.3%) showed evidence of local recurrence, and metastases developed in two patients (1.3%). Overall 1- and 3-year recurrence-free survival was 97% and 92%, respectively. Masses that were in the central region and were endophytic had the highest risk for recurrence (hazard ratio, 6.3; p = 0.016).Intermediate-term outcomes of percutaneous RFA are excellent. GA-assisted, contrast-enhanced CT-guided percutaneous RFA demonstrates a high initial ablation success rate. However, endophytic and interpolar lesions are at higher risk for recurrence.

Introduction and Objective Recent advances in magnetic resonance (MR) technology have allowed for high-resolution ex vivo spectroscopy on small, intact tissue samples. We examined the capability of 1 H magnetic resonance magic angle spinning (MR-MAS) to correctly characterize post–radiofrequency ablation (RFA) renal biopsies from human samples, compared with standard histology and cross-sectional imaging. Methods A minimum of two, 18G, percutaneous renal biopsies were obtained from ten biopsy-confirmed renal tumors at a mean 26.6 mo (range, 15–48) post-RFA. All patients were considered free of disease by computed tomography criteria. A portion of each sample was immediately frozen at −80°C for spectroscopy and the remainder used for pathological analysis. 1 H MR-MAS was performed blinded with a 14.1-tesla field strength. Prior renal biopsies from nonablated tissue were used as positive controls for the spectral analysis. Concordance between, computed tomography, histology, and MR-MAS was analyzed. All spectroscopy was processed with VNMR software. Results Histological analysis of all ten post-RFA biopsies demonstrated no cancer or viable tissue. All MR-MAS spectral peaks for each biopsy were consistent with necrosis and, more importantly, indicated an absence of small molecule metabolites characteristic of both normal and malignant renal tissue. Both MR-MAS and histology confirmed, in each case, the conventional computed tomography determination of complete ablation. Conclusions MR spectroscopy can correctly diagnose the molecular absence of disease in post-RFA tissue biopsies. This proof of principle study warrants in vivo evaluation to confirm the clinical correlates of this modality.

Objectives Optical reflectance spectrophotometry (ORS) is part of a group of novel techniques that have demonstrated promise for the assessment and differentiation of various solid tumors. In this study, we evaluated the ability of ORS to differentiate malignant from benign kidney tumors at surgery. Methods From January to April 2007, we completed optical spectroscopy measurements (OSM) at several standardized tumoral and normal parenchymal locations immediately after specimen removal during radical or partial nephrectomy. The depth of tissue penetration with our specific probe was 1 mm. We compared the slopes of the optical reflectance curves between 630- and 900-nm wavelengths and assessed the correlation between benign and malignant tumors. Results There were 8 partial and 13 radical nephrectomies for 6 benign (oncocytomas) and 15 malignant (14 clear cell and 1 papillary) tumors. Overall, benign and malignant OSM slopes were significantly different ( P = .005). In the near-infrared region, there was excellent correlation among benign ( r = .99) and malignant OSM ( r = .97). On the contrary, there was a poor correlation coefficient when we compared benign and malignant tumors ( r = .49). Conclusions Optical reflectance spectrophotometry may be a novel real-time method to distinguish malignant from benign tumors in vivo. However, we performed these pilot study measurements immediately after specimen removal, and therefore expansion to in situ assessments is necessary.

Radio frequency ablation is an emerging nephron sparing treatment option in select patients with small renal tumors. Some have questioned the completeness of cell death and the reliability of axial imaging for radio frequency ablation followup. We present results in patients with no evidence of radiographic active disease who underwent biopsy more than 1 year following ablation.Patients who had no clinical evidence of disease, defined as absent lesion growth and contrast enhancement on computerized tomography, 1 year or more following radio frequency ablation underwent percutaneous renal biopsy to evaluate cell viability in the ablative zone. A total of 19 patients (20 lesions) were included in the study. Histological comparison of pre-ablation and post-ablation specimens was performed using hematoxylin and eosin staining.Pre-ablation biopsies confirmed that 17 of 20 tumors were renal cell carcinoma, while the remaining 3 were oncocytoma. Following ablation at a mean followup of 26.9 months (range 13.1 to 58.0) all 20 lesions were stable in size without evidence of contrast enhancement on computerized tomography. At repeat biopsy all histology specimens showed unequivocal tumor eradication with no evidence of cellular viability. Histological changes beyond 1 year demonstrated coagulative necrosis, hyalinization, inflammatory cell infiltration and residual ghost cells.Pathological examination of radiographically negative lesions biopsied more than 1 year following radio frequency ablation confirmed no evidence of disease in all specimens. Therefore, axial imaging can reliably monitor treatment efficacy in the long term. Chronic changes after radio frequency ablation demonstrate coagulative necrosis and nonviable cells. This suggests an evolution of pathological changes that renders early post-ablative biopsy unreliable.

HABIB 4X is a laparoscopic focal radiofrequency-coagulation (FRFC) device utilized in liver and kidney resections to facilitate dissection while minimizing blood loss. We evaluated the ergonomics and safety of a laparoscopic FRFC device for a non-ischemic laparoscopic partial nephrectomy (LPN) in a survival porcine model.Five female pigs (10 renal units) underwent 14 laparoscopic transperitoneal partial nephrectomies using the laparoscopic FRFC device without hilar clamping. In phase 1, either one or multiple segments of the lower, upper, or middle pole were resected following FRFC of the resection plane. Large entries into the collecting system were sutured, while very small rents were left open. Following 2-week survival, a laparoscopic FRFC-assisted heminephrectomy without hilar clamping was performed on the opposite renal unit (phase 2). Both kidneys were then harvested for histologic examination. Retrograde pyelography (RGP) was used to assess the collecting system integrity of the kidneys treated in phase 1.All 14 LPNs were performed successfully without hilar clamping or open conversion. On average, the resected segments comprised 12.3% of the kidney in phase 1 and 34.8 % in phase 2, with a mean estimated blood loss of 45 mL and 76.5 mL, respectively. At harvest, no hematomas or perinephric collections were observed. RGP revealed urinary extravasation in two renal units that were not repaired. Histologic examination of the resection margin revealed hemorrhage and inflammation with some hyalinization of the proximal and distal tubules, none extending deeper than 3 mm.The FRFC-assisted non-ischemic porcine LPN is feasible and safe and can be accomplished with minimal bleeding, even with large resections. The laparoscopic FRFC device holds promise in decreasing the inherent difficulty of LPN by obviating the need for laparoscopic suturing to control small parenchymal vessels, as well as in reducing the deleterious effects of warm renal ischemia. Clinical evaluation of this device is warranted.

We assessed the feasibility of single keyhole laparoscopic surgery using a novel transabdominal magnetic anchoring and guidance system platform in the porcine model.A collaborative research group was formed to build a prototype system of magnetically anchored instruments for trocar-free laparoscopy. The design mandate was that the developed technology should be able to deploy into the insufflated abdomen through an existing 12 mm diameter trocar and then be moved into position in the peritoneum by manipulating external magnets. The magnetic anchoring and guidance system concept was advanced to a working prototype with a system of external magnetic anchors, an internal camera system and a hook cautery supported by an intra-abdominal robotic arm. This prototype system was then evaluated in vivo in a porcine laparoscopic nephrectomy model.Two nonsurvival porcine laparoscopic nephrectomies were successfully completed without complications via a single 15 mm transumbilical trocar using the prototype magnetic anchoring and guidance system camera and the magnetically anchored robotic arm cauterizer. A conventional laparoscopic grasper was used for retraction through the 15 mm trocar after magnetic anchoring and guidance system deployment. The renal artery and vein were transected with a conventional Endo-GIA stapler introduced through the 15 mm trocar. Procedure time was not recorded and blood loss was minimal.Single trocar laparoscopic nephrectomy using magnetically anchored instrumentation is technically feasible, demonstrating that intracorporeal instrument manipulation may overcome the limitations of current laparoscopic and robotic surgery by allowing unhindered intra-abdominal movement. This single access technique may be used with natural orifice surgery approaches and it has the potential to realize incision-free intra-abdominal surgery.

To compare stone retrieval and release from seven basket designs in vitro.We tested two tipped and one tipless NCompass models, three other tipless Nitinol designs (NCircle, Sur-Catch, and Dimension), and the Segura Hemisphere for their ability to retrieve and release single beads 8, 6, 5.6, and 5 mm diameter and multiple beads 3.6 mm diameter in both a ureteral and a caliceal model in three separate attempts.In the ureteral model, all baskets were successful in retrieving all sizes of single beads. With multiple 3.6-mm beads, only the NCompass and Dimension designs were able to retrieve at least two of three beads in all attempts. With the exception of the Segura Hemisphere, all designs were successful in releasing all bead sizes. In the caliceal model, only the NCircle, Dimension, and tipless NCompass models were able to retrieve all bead sizes in 100% of the trials. The tipped NCompass and Hemisphere designs were unable to retrieve any beads in this model. The Sur-Catch basket was successful in the retrieval of large beads only. The Dimension articulating design was the only basket able to release all bead sizes in all attempts. The tipless NCompass basket did not release any of the beads once engaged.Nitinol basket designs show excellent retrieval and release capabilities in the in-vitro ureteral model. The articulating Nitinol basket has the best stone-releasing capability of all baskets tested.

Percutaneous renal access is an integral step in percutaneous renal drainage and percutaneous nephrolithotomy. Urologists are increasingly obtaining access themselves, as this eliminates reliance on a second "surgeon" and increases flexibility with respect to procedure timing and the location of the access tract. Surprisingly few models have been developed to train urologists in percutaneous renal access. Harvested porcine kidney/ureter units mounted so they can be viewed radiographically and accessed by needle puncture through material simulating the human flank have been incorporated into two models. The PERC Mentor (Simbionix; Lod, Israel) is a virtual-reality simulator developed specifically for training in percutaneous renal puncture. Hands-on intraoperative training continues to be the primary method for learning percutaneous renal access. However, bench model and simulator-based education offer a useful adjunct.

We estimated the incidence of a crossing vessel at the normal ureteropelvic junction (UPJ) in patients undergoing ureteroscopy and endoluminal ultrasonography for indications other than UPJ obstruction.Endoluminal ultrasonography was performed in 141 patients undergoing upper tract endoscopy for various indications excluding UPJ obstruction. A detailed description of the anatomy of the UPJ as well as the location and size of crossing vessels was included in the operative note. Charts were reviewed to determine the precise anatomy of the UPJ.The overall incidence of crossing vessels at the unobstructed UPJ was 19.2%. Endoluminal ultrasonography demonstrated a crossing vessel in 13.2% of patients with ureteral narrowing or stricture, 31.3% of those with tumors or filling defects, 10.5% of those with submucosal calculi and 16.7% of patients with ureteral diverticula. In cases where the position of a crossing vessel was ascertained, 41% were anterior to the ureter, 28% anterolateral, 24% anteromedial and 7% posterior. There was a statistically significant difference in the frequency of vessels at the UPJ in patients with and without obstruction examined with endoluminal ultrasound (p0.0001).A crossing vessel at the UPJ is seen with endoluminal ultrasound in 19.2% of patients with a normal UPJ. This incidence is lower than that seen in patients with obstructed UPJ. Many of these vessels are related to the lateral surface of the UPJ and there was no area that was always free of vessels.

Laparoscopic dismembered pyeloplasty is an acceptable option for ureteropelvic junction (UPS) obstruction in the pediatric population. We compared our results with dismembered and nondismembered laparoscopic pyeloplasty.A series of 26 children between the ages of 8 months and 15 years (mean age 5 years) underwent transperitoneal laparoscopic pyeloplasty for an obstruction not caused by a crossing vessel. Nineteen had an Anderson-Hynes dismembered pyeloplasty (AH), while the remaining seven had a nondismembered pyeloplasty in a Heineke-Mikulicz fashion (HM). The outcome measures were operative time, length of hospital stay, and resolution of obstruction by ultrasonography and diuretic radionuclide imaging.The mean operative time was 3.1 hours and 2.5 hours for AH and HM, respectively. No difference in hospital stay was noted, with a mean of 3 days. The stent was removed 6 weeks later. Four of the seven patients having nondismembered procedures presented with acute flank pain within 3 days of stent removal. The AH pyeloplasty produced a 94% rate of resolution of UPJ obstruction, while the HM patients did poorly, with a success rate of only 43% (P = 0.002; Fisher's exact test).We believe that for UPJ obstructions in children not involving a crossing vessel, laparoscopic dismembered (AH) pyeloplasty may be considered a safe alternative.

We present our experience with transperitoneal laparoscopic pyelolithotomy in pediatric patients in whom percutaneous renal access failed and the stone burden warranted open intervention.A transperitoneal laparoscopic approach was used for pyelolithotomy in 8 patients 3 months to 10 years old (mean age 4 years). Percutaneous access failed secondary to a nondilated system and/or an occluding lower pole calculus. Inclusion criteria were failed percutaneous access secondary to a nondilated system and/or stone occlusion of the lower pole system and failed shock wave lithotripsy or a stone burden of greater than 2.5 cm2. A posterior pelviotomy was made. Stones in the renal pelvis were removed with rigid graspers under direct laparoscopic vision. A flexible cystoscope was introduced through a port if caliceal stones were present. The renal pelvis was reconstructed. A watertight anastomosis was verified.Average operative time was 1.6 hours (range 0.8 to 2.3). Mean hospital stay was 2.15 days (range 2 to 3). A range of 1 to 3 stones (median of 1) were removed and the mean stone burden was 2.9 cm2. No intraoperative complications were noted. Stone analysis revealed 3 patients with calcium oxalate stones, 1 with a calcium phosphate stone and 4 with cysteine stones. There was 1 patient with stone recurrence at a mean followup of 12 months (range 3 to 20). Thus, the overall long-term stone-free rate was 87.5%.Transperitoneal laparoscopic pyelolithotomy is feasible when percutaneous access fails and open pyelolithotomy is considered due to a large stone burden.

There have been improvements in the outcome of patients with clinically localized prostate cancer treated by radical prostatectomy. However, some patients treated with radical prostatectomy will have clinical or biochemical progression. These men are at increased risk of dying of their disease. Identification of patients with adverse features at the time of radical prostatectomy may permit the use of additional multimodality therapies to improve outcomes. Whether this additional multimodality therapy should be administered in the neoadjuvant or adjuvant setting remains controversial. Further, whether a patient at increased risk for progression after radical prostatectomy requires additional therapy before the development of documented progression remains controversial. This article reviews the potential multimodality approaches to prevent or delay recurrence of prostate cancer in patients undergoing surgical treatment for prostate cancer.

OBJECTIVE To assess the functional and histological effects of a bovine thrombin topical haemostatic agent used clinically to aid in surgical haemostasis (FloSealTM, Baxter International Inc., Deerfield, IL, USA) on the cavernous nerves in a canine model of survival, as there are concerns that the fibrotic/inflammatory response to this product could affect neural function. MATERIALS AND METHODS In phase I, nine adult male dogs had the bilateral neurovascular bundles (NVBs) dissected. A small intravenous catheter placed directly into the erectile bodies of the penis was used to record the intracorporal pressure (ICP). Erection was induced by electrical stimulation of the NVB on each side. After intraoperative randomization to treatment or control, 5 mL of FloSeal was unilaterally applied along the NVB on the treatment side. In phase II, after 2 weeks of survival, both control and treatment NVB were again dissected and re-stimulated to produce an erectile response. The mean arterial pressure and ICP were recorded. The prostate and the NVBs were then removed for histological analysis. RESULTS All dogs achieved erections after electrical stimulation on both the control and treatment side. There was no statistically significant difference in absolute ICP, pressure increase from baseline or systemic pressure after stimulating the NVB on the treatment side between phases I and II. Histological analysis showed a giant-cell reaction around the FloSeal granules and mild focal perineural oedema, but the cavernous nerves were otherwise normal in appearance. CONCLUSION In this short-term functional study, FloSeal did not adversely affect cavernous nerve function, measured as the erectile response to electrical stimulation. We found no evidence contraindicating its use during radical prostatectomy.

A transabdominal magnetic anchoring and guidance system (MAGS) deploys multiple instruments through a single 15-mm diameter, transabdominal trocar. These instruments are positioned in the peritoneal cavity and controlled by externally placed magnets to reduce the need for multiple transabdominal trocars. To assess the feasibility of MAGS technology in a single keyhole, complex laparoscopic procedure, nonsurvival porcine nephrectomies were completed without complications via a single 15-mm transumbilical trocar using a prototype MAGS camera and a magnetically anchored, robotic arm cauterizer.

We report a rare case of a strangulated internal hernia behind the common iliac artery after robot-assisted pelvic lymph node dissection. Internal hernias involving the retroperitoneal vascular axis have been reported four times in medical literature. This is the first time it has been seen after robotic surgery.

Objective. As recent participants in an integrated prostate cancer (PCa) care center, we sought to evaluate whether financial investment in an intensity-modulated radiation therapy (IMRT) center resulted in an increased utilization of radiation therapy in our patients with newly diagnosed PCa. Materials & Methods. Following institutional review board approval, we retrospectively reviewed the records of all consecutive patients who were diagnosed with prostate cancer in the 12 months prior to and after investment in IMRT. Primary treatment modalities included active surveillance (AS), brachytherapy (BT), radiation therapy (XRT), radical prostatectomy (RP), and androgen deprivation therapy (ADT). Treatment data were available for all patients and were compared between the two groups. Results. A total of 344 patients with newly diagnosed PCa were evaluated over the designated time period. The pre-investment group totaled 198 patients, while 146 patients constituted the post-investment group. Among all patients evaluated, there was a similar rate in the use of XRT (20.71% versus 20.55%, ) pre- and post-investment in IMRT. Conclusions. Financial interest in IMRT by urologists does not impact overall utilization rates among patients with newly diagnosed PCa at our center.

The introduction and widespread adoption of PSA has revolutionized the way prostate cancer is diagnosed and treated. However, the use of PSA has also led to over-diagnosis and overtreatment of prostate cancer resulting in controversy about its use for screening. PSA also has limited predictive accuracy for predicting outcomes after treatment and for making clinical decisions about adjuvant and salvage therapies. Hence, there is an urgent need for novel biomarkers to supplement PSA for detection and management of prostate cancer. Despite the progress in developing new biomarkers, several obstacles remain before such biomarkers can be clinically used. These challenges include analytical and regulatory barriers, issues with study design and data analysis that lead to lack of reproducibility of promising results, and the lack of large scale trials to adequately assess the utility of promising biomarkers. In this article we discuss the challenges in biomarker research and the statistical considerations for biomarker evaluation. There is a plethora of promising blood and urine based biomarkers. For the purpose of this review, we focus on PSA derived forms, human kallikrein 2, Early Prostate Cancer Antigen, Transforming Growth Factor-Beta 1 and Interleukin-6, Endoglin, PCA3, AMACR and ETS Gene Fusions. These biomarkers have shown promise in early studies and are at various stages of development. However, in the future it is very likely that a panel of biomarkers will be used to achieve sufficient degree of certainty in order to guide clinical decisions. To be able to be used commercially such a panel will have to answer clinically relevant questions in a simple and cost-effective way.

Objectives To evaluate whether the use of silver-coated catheters increased the risk of developing urethral stricture disease after robotic-assisted laparoscopic radical prostatectomy (RALP). Recently, silver alloy-coated Foley catheters have been shown to decrease the risk of catheter-associated urinary tract infections. Other than the increased cost, no disadvantages to the use of these catheters have been reported. Material and Methods We switched to routine use of the Bardex I.C. silver alloy-coated Foley catheters for all urologic procedures on November 1, 2008. After institutional review board approval, we retrospectively reviewed the records of all consecutive patients who had undergone RALP 12 months before and after the catheter change. The primary outcome was the rate of urethral strictures after RALP. Results A total of 188 RALPs were performed during the 12 months before the catheter change. No patients who underwent RALP in the months before the catheter change had developed a new postoperative urethral stricture. In the 12 months after the change to the silver-coated catheters, 217 RALPs were performed. Six patients after RALP using silver-coated catheters developed new strictures, at a rate of 2.8% (P = .03). Conclusions Silver alloy-coated urinary catheters might increase the risk of developing urethral strictures after RALP compared with standard noncoated catheters. Additional evaluation by a large randomized prospective trial is warranted to elucidate the true risk of stricture formation.

Renal cysts are the most common renal masses and occur in up to 50% of individuals over the age of 50 years (1,2). Although renal cysts may be either congenital or acquired, most are simple, asymptomatic, and of unknown etiology. Intervention is needed when cysts are determined to be complex by radiographic criteria or when they are associated with pain, infection, hemorrhage, or urinary obstruction. Some congenital diseases such as autosomal dominant polycystic kidney disease (ADPKD), the most common form of renal cystic disease in the United States, are commonly associated with symptomatic cysts (3). Other cystic diseases such as von-Hippel-Lindau (VHL), tuberous sclerosis, multilocular cystic nephroma, and acquired cystic disease have a predisposition toward malignant degeneration. The need for intervention in some cases of symptomatic or suspicious cysts has led to the development of less invasive strategies for renal cyst management (4). This chapter will discuss the role of laparoscopy in evaluation and management of renal cysts.

To compare kidney oxygenation profiles between partial and complete renal artery clamping during nephron sparing surgery (NSS) in a porcine model.Twelve female farm pigs underwent a laparoscopic nephrectomy. Subsequently, an open partial nephrectomy was performed on the remaining kidney using either total (n = 6, TC) or partial (n = 6, PC) clamping of the renal artery. Real time renal partial oxygen pressure (rPO2) was monitored using a Licox probe (Integra, San Diego, CA). Creatinine levels were measured prior to open partial nephrectomy and on POD #3 and #7. The remaining kidney was harvested for pathologic evaluation.Compared to TC, the PC group demonstrated a more favorable renal oxygenation profile during the NSS. Specifically, rPO2 decreased less from baseline (58% versus 84%, p = 0.03), took a longer interval to nadir (23.1 min versus 8.7 min, p = 0.04), and experienced a more rapid recovery to maximal or baseline values (4.8 min versus 10.4 min, p = 0.03) in the PC group. Furthermore animals undergoing TC had significantly higher creatinine levels at POD #3 (2.2 mg/dl versus 1.6 mg/dl, p = 0.03) and POD #7 (2.5 mg/dl versus 1.7 mg/dl, p = 0.009). Histological analysis demonstrated varying levels of acute inflammation in the two groups. Finally, the intraoperative blood loss was greater in the PC versus TC group (40 cc versus 10 cc, p = 0.04).In this porcine model, partial clamping of the renal artery during NSS was feasible and demonstrated a favorable renal oxygenation profile. Theoretically, intraoperative rPO2 monitoring may provide a novel means to allow real time assessment and titration of kidney perfusion during partial nephrectomy.

With the expanding role of laparoscopy in urologic practice, efficient and safe training has become paramount. Virtual reality simulation may potentially aid training, but it requires validation before it can be incorporated into training programs. The objective of this study was to assess whether training on a virtual reality (VR) laparoscopy simulator (LAP Mentor) can improve performance of virtual laparoscopic procedures.After a basic introduction to the LAP Mentor, 32 inexperienced medical students performed a baseline VR cholecystectomy that was observed and scored by two observers using the Objective Structured Assessment of Technical Skills (OSATS). The students were then randomized to two groups: Group 1 trained on the simulator without supervision during a total of six 30-minute sessions, and group 2 received no training. Students were then reevaluated on a second VR cholecystectomy by the same observers.All 32 students completed the study. The two groups were comparable with regard to baseline OSATS scores (group 1, 16.6+/-4.3 v group 2, 15.67+/-6.3, P=0.2). On the second evaluation, the trained students (group 1) performed significantly better than the control group (group 2) (27.9+/-7.2 v 17.6+/-6.2, P0.001). Group 1 students outperformed group 2 students in each category of the OSATS. Moreover, trained students improved their scores by at least 20% (P0.001) in each category, while the untrained students improved only in the "knowledge of procedure" category by 25% (P=0.03).Skills training on a LAP Mentor VR simulator improved VR surgical performance. Before incorporating this simulator into resident education, the LAP Mentor will have to undergo testing for predictive and construct validity.

Virtual reality simulators provide a safe and efficient means of acquiring laparoscopic skills. We evaluated whether training on a virtual reality laparoscopic cholecystectomy simulator (Lap Mentor) improves the performance of a live, unrelated laparoscopic urological procedure.A total of 32 medical students with no previous laparoscopic experience were oriented to the Lap Mentor, and then performed virtual reality laparoscopic cholecystectomy which was assessed by 2 experienced laparoscopists using the previously validated Objective Structured Assessment of Technical Skills scoring. Subjects were randomized to group 1, in which participants completed 6, 30-minute virtual reality training sessions within 3 weeks, or group 2, in which participants received no training. All participants then performed live laparoscopic nephrectomy in a porcine model and performance was evaluated using Objective Structured Assessment of Technical Skills by 2 experts blinded to training status.Mean total pretraining laparoscopic cholecystectomy Objective Structured Assessment of Technical Skills scores were comparable between the groups (16.9 +/- 4.3 for group 1 vs 15.4 +/- 6.2 for group 2, p = 0.4). After training total Objective Structured Assessment of Technical Skills scores for live porcine laparoscopic nephrectomy were significantly higher in group 1 compared to group 2 (21.0 +/- 6.8 vs 15.7 +/- 6.6, respectively, p = 0.03). Likewise, individual subcategory Objective Structured Assessment of Technical Skills scores were higher in group 1 than in group 2, although significant differences were noted only in the categories of instrument handling and knowledge of the procedure.Surgical skills acquired as a result of training on a virtual reality laparoscopic simulator are not procedure specific but improve overall surgical skills, thereby translating into superior performance of an unrelated live laparoscopic urological procedure.

OBJECTIVE To compare the costs and morbidity of laparoscopic radiofrequency ablation (LRFA) and laparoscopic partial nephrectomy (LPN) for treating small localized renal tumours. PATIENTS AND METHODS We retrospectively analysed the outcomes of 88 patients treated at our institution for a renal tumour either by LPN (50) or LRFA (38) between March 2000 and May 2006. Patients with multiple tumours, combined LRFA and LPN, and those who had other simultaneous surgical procedures were excluded. Clinical variables and outcomes were analysed for each patient. Direct cost data were available for 40 patients treated with LPN and 14 with LRFA. Continuous and categorical variables were compared using an independent t-test and chi-square test, respectively. RESULTS The tumour size was comparable in each group; patients in the LRFA group had more comorbidities (P = 0.01) and a higher overall mortality rate (P = 0.01) but no patient died from cancer. Operative duration, estimated blood loss and length of stay were significantly shorter in the LRFA group but there was no difference in complication rate. LRFA was less costly than LPN ($6103 vs $6808, P = 0.3) but not statistically significantly. The cost savings from the shorter operative duration and length of stay were reduced by the cost of probe. With a median follow-up of 20 months there was no difference in oncological outcome. CONCLUSION Patients undergoing LRFA tend to be older and have more comorbidities than those treated with LPN. The cost is minimally lower for LRFA, secondary to the added cost of the probe. LRFA might be a good alternative treatment in patients at higher risk of surgical complications, but LPN provides good results when done by an experienced surgeon.

To compare the efficacy of conventional and articulating laparoscopic needle-drivers for performing standardized laparoscopic tasks by medical students with no previous surgical experience.Twenty medical students with no surgical experience were randomly assigned to two equal groups, one using a conventional laparoscopic needle-holder (Karl Storz, Tuttlingen, Germany) and the other using a first-generation articulating laparoscopic needle-holder (Cambridge Endo, Framingham, MA, USA). Each student performed a series of four standardized laparoscopic tasks, during which speed and accuracy were assessed. The tasks tested needle passage through rings (1), an oblique running suture model (2), a urethrovesical anastomosis model (3) and a model simulating renal parenchymal reconstruction following partial nephrectomy (4).Tasks 1 and 3 were completed significantly more quickly by those using the conventional instruments (P0.05), but there was no statistically significant difference for task 2 and 4 (P0.05). Those using conventional instruments were significantly more accurate in all of the tasks than those using the articulated instruments (P0.05).The conventional laparoscopic needle-driver allowed laparoscopy-naive medical students to complete a series of standardized suturing tasks more rapidly and accurately than with the novel articulating needle-driver. Laparoscopic suturing with first-generation articulating needle-drivers might be more difficult to learn, secondary to the complexity of physical manoeuvres required for their use.

Optical spectroscopy has been evaluated as an innovative technique for the ex vivo study of renal and prostate tumors. In this pilot study we assessed the ability of optical reflectance spectroscopy to reliably differentiate tumor and normal tissue in renal specimens.From January to April 2007 we completed optical reflectance spectroscopy measurements at several standardized tumor and normal parenchymal locations immediately after kidney tumor removal. The slopes of the optical reflectance spectroscopy curves were compared, and the correlation between tumor and normal parenchyma reflectance was assessed.Reliable measurements were obtained from 13 radical and 8 partial nephrectomy specimens. Histology was malignant in 15 cases (clear cell in 14 and papillary in 1) and benign in 6 cases of oncocytoma. Overall we found a significant difference between the average optical reflectance spectroscopy slopes of tumor and normal parenchyma (p = 0.03). In individual radical nephrectomy specimens optical reflectance spectroscopy measurements at different locations in the tumor showed an excellent correlation (r = 0.968). Normal parenchymal measurements also correlated well (r = 0.88), although there was poor correlation between tumor and nontumor tissue in the specimen (r = 0.07). In the partial nephrectomy subset we also found a close correlation among measurements made on the normal parenchymal margin of the tumor (r = 0.94) except in 1 case of a positive margin (oncocytoma), in which the measurement from the positive margin site did not correlate with that of the adjacent parenchymal margin (r = 0.48).Optical reflectance spectroscopy can help distinguish tumor from normal renal tissue in specimens immediately removed at surgery. Optical reflectance spectroscopy may allow real-time assessment of positive margins during partial nephrectomy.

Natural orifice translumenal endoscopic surgery (NOTES) is an evolving field and suitable instruments are lacking. The purpose of this study was to perform transvaginal cholecystectomies using instruments incorporated into a magnetic anchoring and guidance system (MAGS). Non-survival procedures were conducted in pigs (n = 4). Through a vaginotomy created under direct vision, a rigid access port was inserted into the peritoneal cavity and used to maintain a CO2 pneumoperitoneum. MAGS instruments were deployed through the port and held in place on the peritoneal surface using magnetic coupling via an external handheld magnet which was optionally exchanged for an 18ga percutaneous threaded needle anchor; instruments included a tissue retractor (a clip-fixated magnet or flexible graspers) and a cautery dissector. A gastroscope was used for visualization. The first two procedures ended prematurely due to instrumentation shortcomings and inadvertent magnetic coupling between instruments; one case required a laparoscopic rescue. Three new forms of instrumentation were developed: (1) a longer access port (50 cm) which provided easier deployment of instruments and suitable reach, (2) a more robust cauterizer with a longer, more rigid, pneumatically deployed tip with better reach and sufficient torque to allow blunt dissection, and (3) a more versatile tissue retractor with bidirectional dual flexible graspers which provided excellent cephalad fundus retraction and inferiolateral infundibulum retraction. With these modifications, 100% of the cholecystectomy was completed in the third and fourth animals using only a NOTES/MAGS approach. Retrieval of the tissue retractor resulted in a rectal injury in the third animal but further procedural modifications resulted in a successful procedure in the fourth animal with no complications. While still under development with more refinements needed, completely transvaginal cholecystectomy using MAGS instruments is feasible. By offering triangulation and rigidity, MAGS may facilitate a NOTES approach while alleviating shortcomings of a flexible platform.

Purpose of review Ureteroscopic instruments, both endoscopic and working devices, continue to evolve. Changes in instrumentation have necessitated concurrent modifications in ureteroscopic techniques over the years. The safety and efficacy of the ureteroscopic approach for the treatment of renal and ureteral calculi, however, have continued to improve. Recent findings This review emphasizes the recent advances in the major groups of instruments employed for ureteroscopy. Among the endoscopic instruments, the flexible ureteroscopes have undergone the most notable advances, benefiting from greatly improved deflection and durability. Progress has been made in adjunctive instruments as well. Current stone retrieval devices composed of nitinol-based wire technology are able to easily secure fragments from the most peripheral calices. The holmium laser is a versatile device with proven safety and effectiveness as an endoscopic lithotrite. Summary The availability and coordinated use of the latest ureteroscopic instruments have resulted in better treatment outcomes, thus expanding the use of ureteroscopy as a first-line option for the treatment of calculi in appropriate cases. Urologists should be familiar with currently available instrumentation in order to optimize their equipment.

The field of prostate cancer has witnessed dramatic improvements in the management of localized prostate cancer over the last 20 yr. It is thought that stage migration, probably because of screening efforts, combined with improvements in treatment modalities, is largely responsible for these outcomes. The initiation of prostate-specific antigen (PSA) screening has led not only to earlier detection of prostate cancer but also to detection at a lower stage of disease (1). Many more patients are now candidates for a definitive local therapy. However, there are patients with localized prostate cancer treated with curative intent who will have either rising PSA levels or clinical progression and who will require a secondary intervention (2). It is estimated that approx 134,000 patients receive localized disease treatment annually, and of those as many as 50,000 may experience PSA recurrence (3). Biochemical failure is defined as a detectable PSA level after definitive local therapy without clinical evidence of local or distal recurrence and is the most common pattern of disease progression. However, there is a subset of patients with biochemical recurrence after radical prostatectomy who on long-term follow-up do not exhibit PSA or clinical progression (4). Shinghal et al. (4) identified 14 patients (8.8% of biochemical recurrences) with a detectable PSA level after radical prostatectomy, yet without clinical or PSA progression at a mean follow-up of 10.3 yr. They described a benign clinical course in these patients, obviating the need for adjuvant therapy.

Renal cryoablation is a successful nephron-sparing treatment alternative for selected patients with small renal tumors. The purpose of this study was to compare the effects of the number of freeze cycles (one v two) and the thaw process (active v passive) on renal tissue following cryodestruction.Sixteen female mongrel dogs (19.9 +/- 2.1 kg) were randomly divided into four groups and underwent transabdominal laparoscopic access by standard techniques. Tissue freezing was performed using argon gas following interstitial cryoprobe (3 mm) placement into the upper and lower poles of the left kidney. Single active (SA), single passive (SP) double active (DA) or double passive (DP) 15-minute treatment cycle(s) were carried out via the CRYOcare Cryosurgical Unit (Endocare, Irving, CA) on eight kidneys each. An active thaw process with helium gas or a passive thaw process was initiated after each freeze period. The cryoprobe was removed when the temperature reached 0 degrees C. Four weeks following cryosurgery, animals were sacrificed, and the renal tissue was evaluated grossly and histologically.Interstitial cryoprobe temperatures decreased from 31.3 degrees C +/- 1.4 degrees C to -142 degrees C +/- 1.0 degrees C following the 15-minute freeze cycle. The temperature reached 0 degrees C significantly faster following active thaw than with the passive process (2.13 +/- 0.24 min/freeze cycle and 15.18 +/- 2.97 min/freeze cycle, respectively; P0.0001). Grossly, each lesion consisted of a central area of necrosis surrounded by a rim of white tissue. On microscopic examination, each lesion consisted of a central area of liquefaction necrosis (LN) surrounded by various degrees of fibrosis and granulation tissue admixed with residual parenchyma. The size of the LN was significantly different in tissues subjected to double and single freeze cycles when compared across both thaw processes (active and passive). There was no significant difference in the overall lesion volume following DA, DP, SA, or SP.Renal cryodestruction via laparoscopic access achieves complete tissue ablation without complications. The double freeze cycle produced significantly larger areas of LN than the single freeze regardless of the thaw process. The type of thaw process did not affect the amount of tissue damage. Utilizing a double 15-minute freeze cycle with the faster active thaw process will effectively cryoablate renal tissue as well as significantly reduce overall operative time.

OBJECTIVE To report the first intermediate-term oncological outcomes of laparoscopic radiofrequency coagulation followed by laparoscopic partial nephrectomy (RF-LPN) to treat small renal masses, as LPN is limited by the technical difficulty of efficient tumour resection and parenchymal repair during warm ischaemia of the kidney. PATIENTS AND METHODS A prospective database was searched to identify patients treated with RF-LPN; in each case the tumour was first RF coagulated with a margin of normal parenchyma, and then excised. Only fibrin glue was applied to the haemostatic resection site to prevent urinary leaks. In all, 32 tumours were treated with this approach, and a radiographic follow-up was completed yearly. RESULTS All PNs were accomplished with no hilar clamping, with a mean blood loss of 80 mL; 72% of masses were renal cell carcinoma. There was a positive margin in four masses (13%); 29 tumours (mean size 1.9 cm) were eligible for analysis of oncological outcomes, with a mean follow-up of 31 months. There were no tumour recurrences at the last follow-up, giving a cancer-specific survival rate of 100%. CONCLUSIONS RF-LPN with no hilar clamping simplifies the surgical technique and appears to have excellent cancer control in the intermediate term. In the few patients with a positive surgical margin, it is possible that coagulation beyond the tumour margin kills any residual microscopic tumour, minimizing or obviating the risk of tumour recurrence. Nevertheless, vigilance during tumour excision and margin identification is mandatory.