Impact of Renal Access Angle and Speed of Nephroscope Retrieval Movements on the Vortex Effect

OBJECTIVE

To analyze the influence of different renal access angles (AAs) and nephroscope retrieval speeds on the efficacy of the vortex effect (VE) in mini-percutaneous nephrolithotomy (mini-PCNL). This study aimed to understand the poorly understood physical components of the VE.

MATERIALS AND METHODS

A Pexiglas™ (KUS®) model was built based on the dimensions of a 15/16 F mini-PCNL set (Karl Storz). The flow rate was continuous via an automatic pump and calibrated to achieve hydrodynamic equivalence to the real equipment. One experiment consisted of manually retrieving all 30 stone phantoms (3 mm diameter) utilizing only the VE. Cumulative time to retrieve all stones was measured. An accelerometer recorded instant speeds of the nephroscope every 0.08 seconds (s), and 3 experiments were performed at each angle (0°, 45°, and 90°). A logistic regression model was built utilizing maximum speeds and access angles to predict the effectiveness of the VE.

RESULTS

Mean cumulative time for complete stone retrieval was 28.1 seconds at 0° vs 116.5 seconds at 45° vs 101.4 seconds at 90° (P < .01). We noted significantly higher speeds at 0° compared to 45° and 90° (P < .01); however, differences in average and maximum speed between 45° and 90° were not statistically significant (P = .21 and P = .25, respectively). The regression model demonstrated a negative association between increasing maximum speed and VE's effectiveness (OR 0.547, CI 95% 0.350-0.855, P < .01). When controlling for maximum speed, the 0° angle had significantly higher chances of achieving at least a partially effective VE.

CONCLUSION

Increasing the renal access angle or nephroscope extraction speed negatively impacts the effectiveness of the VE. This significantly increased procedure time in the laboratory model, suggesting that the VE is less effective at higher sheath angles.

The Vortex Effect in Minimally Invasive Percutaneous Nephrolithotomy

OBJECTIVE

To describe the physical principles of the vortex effect to better understand its applicability in minimally invasive percutaneous nephrolithotomy (MIP) procedures.

METHODS

Two acrylic phantom models were built based on the cross-sectional area (CSA) ratio of a MIP nephroscope and access sheaths (15/16F and 21/22F MIP-M, Karl Storz). The nephroscope phantom was 10 mm in diameter. The access sheaths had diameters of 14 mm (CSA ratio: 0.69) and 20 mm (CSA ratio: 0.30). The models were adapted to generate hydrolysis, and hydrogen bubbles enhanced flow visualization on a green laser background. After calibration, the experimental flow rate was set to 12.0 mL/s. Three 30-second trials assessing the flow were performed with each model. Computational fluid dynamic simulations were completed to determine the speed and pressure profiles.

RESULTS

In both models, as the incoming fluid from the nephroscope phantom attempted to move toward the collecting system, a stagnation point was demonstrated. No fluid entered the collecting system phantom. Utilizing the 14 mm sheath, we observed a random generation of several vortices and a pressure gradient (PG) of 114.4 N/m2 between the nephroscope's tip and stagnation point. In contrast, examining the 20 mm sheath revealed a significantly smaller PG (19.4 N/m2) and no noticeable vortices were noted.

CONCLUSION

The speed of the fluid and equipment geometry regulate the PG and the vortices field, which are responsible for the production of the vortex effect. Considering the same flow rate, a higher ratio between the CSA of the nephroscope and access sheath results in improved efficacy of the vortex effect.

Breakage Costs in Flexible Ureteroscopy: Digital vs. Fiberoptic Modalities

OBJECTIVE

To compare the maintenance costs of digital flexible ureteroscopes (DFU) versus fiberoptic flexible ureteroscopes (FFU) to understand the long-term financial impact associated with breakage in a flexible ureteroscopy (f-URS) program.

METHODS

Data for breakage of FFU and DFU at an academic institution from 2019 to 2021 were obtained from our vendor (Karl Storz) and analyzed by month. Correlation test was used to evaluate significant differences in number of procedures, number of breakage events, breakage rates, and repair cost per month. Cumulative analyses were utilized to examine the number of procedures before failure (time to failure - TTF) and repair costs per procedure (RCpP).

RESULTS

We performed a total of 2,154 f-URS, including 1,355 with FFU and 799 with DFU (P<.001). Although we found a higher number of breakage events in FFU (n=124) than DFU (n=73) (P<.001), the overall breakage rate was similar, 9.9% vs. 8.8%, respectively (P=0.86). On cumulative analysis, both modalities reached the same TTF plateau (11 cases) after 18 months. After 400 cases, the RCpP for DFU was 1.25 times higher than for FFU (P=0.04).

CONCLUSION

Overall, we found no difference in overall scope breakage rates between DFU and FFU. Although there was no difference in TTF over time, at the beginning DFU displayed considerable higher durability, leading to lower RCpP. Furthermore, DFU's endurance leveled off to FFU over time, resulting in higher RCpP after 400 cases. This finding may be explained by the presence of renewed scopes after repair.

On the rocks: can urologists identify stone composition based on endoscopic images alone? A worldwide survey of urologists

PURPOSE

As part of the management of nephrolithiasis, determination of chemical composition of stones is important. Our objective in this study is to assess urologists' accuracy in making visual, intraoperative determinations of stone composition.

MATERIALS AND METHODS

We conducted a REDCap survey asking urologists to predict stone composition based on intraoperative images of 10 different pure-composition kidney stones of 7 different types: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate (CP) apatite, CP brushite, uric acid (UA), struvite (ST) and cystine (CY). To evaluate experience, we examined specific endourologic training, years of experience, and number of ureteroscopy (URS) cases/week. A self-assessment of ability to identify stone composition was also required.

RESULTS

With a response rate of 26% (366 completed surveys out of 1,370 deliveries), the overall accuracy of our cohort was 44%. COM, ST, and COD obtained the most successful identification rates (65.9%, 55.7%, and 52.0%, respectively). The most frequent misidentified stones were CP apatite (10.7%) and CY (14.2%). Predictors of increased overall accuracy included self-perceived ability to determine composition and number of ureteroscopies per week, while years of experience did not show a positive correlation.

CONCLUSIONS

Although endoscopic stone recognition can be an important tool for surgeons, it is not reliable enough to be utilized as a single method for stone identification, suggesting that urologists need to refine their ability to successfully recognize specific stone compositions intraoperatively.

Image Distortion During Flexible Ureteroscopy: A Laboratory Model Comparing Super Pulsed Thulium Fiber Laser vs High-Power Ho:YAG Laser

Purpose: Digital ureteroscopes employ "chip-on-the-tip" technology that allows for significant improvement in image resolution. However, image distortion often occurs during laser lithotripsy owing to acoustic wave production. We sought to compare image distortion using different laser power settings and distances from the laser fiber tip to the scope for the Super Pulsed Thulium Fiber (SPTF) laser and high-power Holmium:YAG (Ho:YAG) laser. Materials and Methods: Ureteroscopy was simulated using a silicon kidney-ureter-bladder model fitted with a 12F/14F access sheath and the Lithovue™ (Boston Scientific), disposable digital flexible ureteroscope. At defined laser parameters (10, 20, 30 and 40 W, short pulse), a 200-μm laser fiber was slowly retracted toward the tip of the ureteroscope during laser activation. Image distortion was identified, and distance from the laser tip to the scope tip was determined. Data from the two lasers were compared utilizing t-tests. Results: After controlling for frequency, power, and laser mode, utilizing 1.0 J of energy was significantly associated with less feedback than 0.5 J (-0.091 mm, p ≤ 0.05). Increased power was associated with larger feedback distance (0.016 mm, p ≤ 0.05); however, increase in frequency did not have a significant effect (-0.001 mm, p = 0.39). The SPFT laser had significantly less feedback when compared with all Holmium laser modes. Conclusions: Increased total power results in image distortion occurring at greater distances from the tip of the ureteroscope during laser activation. Image distortion occurs further from the ureteroscope with Ho:YAG laser than with SPTF fibers at the same laser settings. In clinical practice, the tip of the laser fiber should be kept further away from the tip of the scope during ureteroscopy as the power increases as well as when utilizing the Ho:YAG system compared with the SPTF laser platform. The SPTF laser may have a better safety profile in terms of potential scope damage.

Genomic insights into the evolutionary relationships and demographic history of kiwi

Kiwi are a unique and emblematic group of birds endemic to New Zealand. Deep-time evolutionary relationships among the five extant kiwi species have been difficult to resolve, in part due to the absence of pre-Quaternary fossils to inform speciation events. Here, we utilise single representative nuclear genomes of all five extant kiwi species (great spotted kiwi, little spotted kiwi, Okarito brown kiwi, North Island brown kiwi, and southern brown kiwi) and investigate their evolutionary histories with phylogenomic, genetic diversity, and deep-time (past million years) demographic analyses. We uncover relatively low levels of gene-tree phylogenetic discordance across the genomes, suggesting clear distinction between species. However, we also find indications of post-divergence gene flow, concordant with recent reports of interspecific hybrids. The four species for which unbiased levels of genetic diversity could be calculated, due to the availability of reference assemblies (all species except the southern brown kiwi), show relatively low levels of genetic diversity, which we suggest reflects a combination of older environmental as well as more recent anthropogenic influence. In addition, we suggest hypotheses regarding the impact of known past environmental events, such as volcanic eruptions and glacial periods, on the similarities and differences observed in the demographic histories of the five kiwi species over the past million years.

Bayesian Evaluation of Temporal Signal in Measurably Evolving Populations

Phylogenetic methods can use the sampling times of molecular sequence data to calibrate the molecular clock, enabling the estimation of evolutionary rates and timescales for rapidly evolving pathogens and data sets containing ancient DNA samples. A key aspect of such calibrations is whether a sufficient amount of molecular evolution has occurred over the sampling time window, that is, whether the data can be treated as having come from a measurably evolving population. Here, we investigate the performance of a fully Bayesian evaluation of temporal signal (BETS) in sequence data. The method involves comparing the fit to the data of two models: a model in which the data are accompanied by the actual (heterochronous) sampling times, and a model in which the samples are constrained to be contemporaneous (isochronous). We conducted simulations under a wide range of conditions to demonstrate that BETS accurately classifies data sets according to whether they contain temporal signal or not, even when there is substantial among-lineage rate variation. We explore the behavior of this classification in analyses of five empirical data sets: modern samples of A/H1N1 influenza virus, the bacterium Bordetella pertussis, coronaviruses from mammalian hosts, ancient DNA from Hepatitis B virus, and mitochondrial genomes of dog species. Our results indicate that BETS is an effective alternative to other tests of temporal signal. In particular, this method has the key advantage of allowing a coherent assessment of the entire model, including the molecular clock and tree prior which are essential aspects of Bayesian phylodynamic analyses.

Cystoscopically Placed Pancreatic Duct Stent for Management of Bladder-Drained Pancreas Transplant with Pancreatic Duct Leak

Background: Historically, exocrine pancreas secretions during pancreas transplant were commonly managed by bladder drainage. Although this technique has fallen out of favor because of significant rates of urologic complications, urologists must still be prepared to assist when they arise. We describe the first reported case of a cystoscopically placed pancreatic duct stent for management of a pancreas transplant duodenocystostomy leak in the setting of normal bladder function. Case Presentation: A 63-year-old male with a history of type 1 diabetes mellitus complicated by end-stage renal disease underwent a simultaneous bladder-drained pancreas and kidney transplant 25 years ago. He developed hematuria and acute rejection of his pancreas, with CT showing large volume ascites concerning for pancreatic leak. Cystoscopy revealed an intact and patent duodenal-cystostomy anastomosis; however, intraperitoneal extravasation on intraoperative cystogram raised concern for pancreatic head necrosis. The patient underwent intraperitoneal drain placement and Foley catheter bladder decompression, but drain output and drain amylase and lipase remained markedly elevated. He was taken back to the operating room for attempted cystoscopic stenting of the pancreatic duct, which was effective using a 5F × 4 cm Zimmon^® pancreatic stent. His drain output normalized in the following days and the pancreatic stent and intraperitoneal drain were removed 4 and 5 weeks after discharge, respectively. Outpatient urodynamics revealed no signs of obstruction and his catheter was removed with minimal postvoid residuals on follow-up. Conclusion: Anastomotic leak after duodenocystostomy during pancreas transplant is a complication typically related to elevated intravesical pressures, managed with bladder decompression and subsequent bladder outlet procedure. We present a novel technique for cystoscopic pancreatic duct stenting in the setting of intact anastomosis and normal bladder function with delayed leak secondary to necrotic pancreatic head. Endoscopic stent placement, intraperitoneal drainage, and bladder decompression with Foley catheter are an effective technique to avoid unnecessary reconstructive surgery.

Periureteral Marginal Zone Lymphoma Resulting in Hydronephrosis and Flank Pain in the Absence of Disseminated Disease: Case Report of Two Patients Presenting with Rare But Important Differential

Background: Extrinsic compression of the ureter can result from multiple different malignancies, typically in the presence of known or disseminated disease. Rarely, hydroureteronephrosis and flank pain can occur as the presenting sign and symptom of lymphoma. In this study, we present two cases of primary ureteral obstruction in patients without a prior diagnosis of lymphoma and without bulky retroperitoneal lymphadenopathy. Case Presentation: Case #1 was a healthy 58-year-old man who presented with acute left flank pain. He was found to have left hydroureteronephrosis secondary to a proximal periureteral mass. Diagnostic ureteroscopy demonstrated this to be an extrinsic compression on the ureter and preoperative imaging was negative aside from one enlarged periaortic node. Laparoscopic ureterolysis and biopsy were remarkable for periureteral dystrophic tissue concerning for lymphoma. Case #2 was a 47-year-old woman with a solitary kidney secondary to prior left nephrectomy who presented with hydronephrosis of her solitary kidney and acute kidney injury. Retrograde pyelogram showed high-grade obstruction at the junction of the mid- and distal ureter. Periureteral thickening was noted, but no definitive masses were seen on cross-sectional imaging. Robotic ureterolysis showed dense fibrosis around the ureter. Pathology report from Cases #1 and #2 were both remarkable for marginal zone lymphoma and both patients received bendamustine and rixuximab with resolution of ureteral obstruction and their lymphoma. Conclusion: Ureteral compression as the primary presentation of periureteral lymphoma is a rare but important etiology of extrinsic malignant ureteral obstruction. These cases emphasize that malignant obstruction can occur even in the absence of disseminated disease.

Phylodynamic Model Adequacy Using Posterior Predictive Simulations

Rapidly evolving pathogens, such as viruses and bacteria, accumulate genetic change at a similar timescale over which their epidemiological processes occur, such that, it is possible to make inferences about their infectious spread using phylogenetic time-trees. For this purpose it is necessary to choose a phylodynamic model. However, the resulting inferences are contingent on whether the model adequately describes key features of the data. Model adequacy methods allow formal rejection of a model if it cannot generate the main features of the data. We present TreeModelAdequacy, a package for the popular BEAST2 software that allows assessing the adequacy of phylodynamic models. We illustrate its utility by analyzing phylogenetic trees from two viral outbreaks of Ebola and H1N1 influenza. The main features of the Ebola data were adequately described by the coalescent exponential-growth model, whereas the H1N1 influenza data were best described by the birth–death susceptible-infected-recovered model.

Inferring demographic parameters in bacterial genomic data using Bayesian and hybrid phylogenetic methods

Background

Recent developments in sequencing technologies make it possible to obtain genome sequences from a large number of isolates in a very short time. Bayesian phylogenetic approaches can take advantage of these data by simultaneously inferring the phylogenetic tree, evolutionary timescale, and demographic parameters (such as population growth rates), while naturally integrating uncertainty in all parameters. Despite their desirable properties, Bayesian approaches can be computationally intensive, hindering their use for outbreak investigations involving genome data for a large numbers of pathogen isolates. An alternative to using full Bayesian inference is to use a hybrid approach, where the phylogenetic tree and evolutionary timescale are estimated first using maximum likelihood. Under this hybrid approach, demographic parameters are inferred from estimated trees instead of the sequence data, using maximum likelihood, Bayesian inference, or approximate Bayesian computation. This can vastly reduce the computational burden, but has the disadvantage of ignoring the uncertainty in the phylogenetic tree and evolutionary timescale.

Results

We compared the performance of a fully Bayesian and a hybrid method by analysing six whole-genome SNP data sets from a range of bacteria and simulations. The estimates from the two methods were very similar, suggesting that the hybrid method is a valid alternative for very large datasets. However, we also found that congruence between these methods is contingent on the presence of strong temporal structure in the data (i.e. clocklike behaviour), which is typically verified using a date-randomisation test in a Bayesian framework. To reduce the computational burden of this Bayesian test we implemented a date-randomisation test using a rapid maximum likelihood method, which has similar performance to its Bayesian counterpart.

Conclusions

Hybrid approaches can produce reliable inferences of evolutionary timescales and phylodynamic parameters in a fraction of the time required for fully Bayesian analyses. As such, they are a valuable alternative in outbreak studies involving a large number of isolates.

Electronic supplementary material

The online version of this article (10.1186/s12862-018-1210-5) contains supplementary material, which is available to authorized users.

Improving risk stratification among veterans diagnosed with prostate cancer: impact of the 17-gene prostate score assay

BACKGROUND

Active surveillance (AS) has been widely implemented within Veterans Affairs' medical centers (VAMCs) as a standard of care for low-risk prostate cancer (PCa). Patient characteristics such as age, race, and Agent Orange (AO) exposure may influence advisability of AS in veterans. The 17-gene assay may improve risk stratification and management selection.

OBJECTIVES

To compare management strategies for PCa at 6 VAMCs before and after introduction of the Oncotype DX Genomic Prostate Score (GPS) assay.

STUDY DESIGN

We reviewed records of patients diagnosed with PCa between 2013 and 2014 to identify management patterns in an untested cohort. From 2015 to 2016, these patients received GPS testing in a prospective study. Charts from 6 months post biopsy were reviewed for both cohorts to compare management received in the untested and tested cohorts.

SUBJECTS

Men who just received their diagnosis and have National Comprehensive Cancer Network (NCCN) very low-, low-, and select cases of intermediate-risk PCa.

RESULTS

Patient characteristics were generally similar in the untested and tested cohorts. AS utilization was 12% higher in the tested cohort compared with the untested cohort. In men younger than 60 years, utilization of AS in tested men was 33% higher than in untested men. AS in tested men was higher across all NCCN risk groups and races, particular in low-risk men (72% vs 90% for untested vs tested, respectively). Tested veterans exposed to AO received less AS than untested veterans. Tested nonexposed veterans received 19% more AS than untested veterans. Median GPS results did not significantly differ as a factor of race or AO exposure.

CONCLUSIONS

Men who receive GPS testing are more likely to utilize AS within the year post diagnosis, regardless of age, race, and NCCN risk group. Median GPS was similar across racial groups and AO exposure groups, suggesting similar biology across these groups. The GPS assay may be a useful tool to refine risk assessment of PCa and increase rates of AS among clinically and biologically low-risk patients, which is in line with guideline-based care.

Metastatic prostate cancer in the modern era of PSA screening

Introduction

To characterize initial presentation and PSA screening status in a contemporary cohort of men treated for metastatic prostate cancer at our institution.

Materials and methods

We reviewed records of 160 men treated for metastatic prostate cancer between 2008-2014 and assessed initial presentation, categorizing patients into four groups. Groups 1 and 2 presented with localized disease and received treatment. These men suffered biochemical recurrence late (>1 year) or earlier (<1 year), respectively, and developed metastases. Groups 3 and 4 had asymptomatic and symptomatic metastases at the outset of their diagnosis. Patients with a first PSA at age 55 or younger were considered to have guideline-directed screening.

Results

Complete records were available on 157 men for initial presentation and 155 men for PSA screening. Groups 1, 2, 3 and 4 included 27 (17%), 7 (5%), 69 (44%) and 54 (34%) patients, respectively. Twenty (13%) patients received guideline-directed PSA screening, 5/155 (3%) patients presented with metastases prior to age 55 with their first PSA, and 130/155 (84%) had their first PSA after age 55, of which 122/130 (94%) had metastasis at the time of diagnosis.

Conclusion

Despite widespread screening, most men treated for metastatic prostate cancer at our institution presented with metastases rather than progressed after definitive treatment. Furthermore, 25 (16%) patients received guideline-directed PSA screening at or before age 55. These data highlight that, despite mass screening efforts, patients treated for incurable disease at our institution may not have been a result of a failed screening test, but a failure to be screened.

Findings and Impact of Early Imaging After Partial Nephrectomy

INTRODUCTION

American Urological Association guidelines for surveillance of renal-cell carcinoma after partial nephrectomy recommend imaging within 3-12 months of surgery. Imaging following partial nephrectomy may be difficult to interpret due to the surgical defect, the use of surgical material, and normal postoperative fluid collections. Our primary objective was to evaluate the frequency of indeterminate postoperative imaging results and how those radiographic findings altered patient management.

METHODS

Retrospective chart review from 2006 to 2013 of patients who had undergone open, laparoscopic, and robotic partial nephrectomy at our institution was completed. There was a minimum of 2 years of follow-up imaging. Radiology reports were reviewed from follow-up imaging and were categorized as "normal" or "abnormal."

RESULTS

We identified 180 patients with 127 (70.5%) considered to have normal findings on initial follow-up imaging, and 53 (29.5%) with abnormal findings. Median time to initial postoperative imaging for normal findings was 6.8 months compared with 4.4 months for patients with abnormal postoperative scans (p = 0.02). On subsequent imaging, 60% of abnormal studies were downgraded to normal. The median time to receive a second postoperative image from surgery in the normal and abnormal groups was 13.2 and 10.2 months, respectively. The median time interval to the second imaging study was 6.3 months for normal initial scans compared with 5.2 months for initially abnormal scans (p ≤ 0.01).

CONCLUSIONS

Early postoperative imaging after partial nephrectomy frequently results in "abnormal" findings and more subsequent radiology exams even though the findings rarely represent cancer recurrences. Based on our results, and pending further validation from other centers, we believe postoperative CT or MRI surveillance after partial nephrectomy can be safely deferred until 1 year after surgery.

Robotic-assisted Laparoscopic Pyeloplasty: Analysis of Symptomatic Patients With Equivocal Renal Scans

OBJECTIVES

To review the objective and subjective success rates of robotic-assisted laparoscopic pyeloplasty in symptomatic patients with radiographic findings suggestive of uretero-pelvic junction obstruction (UPJO), but equivocal renal scans (diuretic T1/2 <20 minutes).

METHODS

We reviewed 77 patients with symptomatic UPJO, who underwent robotic-assisted laparoscopic pyeloplasty between August 2006 and March 2013. We grouped patients by renal scan findings into 1 of 2 groups, obstructed (diuretic T1/2 ≥20 minutes) or equivocal (diuretic T1/2 <20 minutes). All patients were symptomatic and had radiographic findings suggestive of UPJO (eg hydronephrosis).

RESULTS

Mean age was 40.7 years (range 17-80) with 70% female. UPJO occurred 44% left and 56% right, with 92% presenting with flank pain. Of 77 patients, 45 had obstruction on renal scan, with 41 (91%) having resolution of obstruction postoperatively and 44 of 45 (98%) having complete resolution of their initial symptoms. Thirty-two patients had equivocal findings with mean diuretic T1/2 of 12.6 minutes (range: 5.5-19.26) on renal scan. In this latter group, patients had significantly less of a decrease in their diuretic T1/2 postoperatively (4 vs 64 minutes, P = .018) and reported less pain resolution (53% vs 98%, P ≤.001) than group 1.

CONCLUSION

Many studies have demonstrated excellent success of pyeloplasty, with most series including patients meeting strict diagnostic criteria for obstruction. Our study examines outcomes in patients with clinically symptomatic UPJO and equivocal diuretic renography. In our cohort, equivocal patients were significantly less likely to have subjective resolution of symptoms than patients in the obstructed group.

Modifier 22 on perioperative outcomes of robotic assisted laparoscopic prostatectomy

INTRODUCTION

Robotic assisted laparoscopic prostatectomy (RALP) is a mainstay in the treatment of prostate cancer. Current procedure terminology (CPT) identifies a case that requires substantially greater effort than usual by using the modifier 22 code (M22). Our objective was to identify the most common etiologies leading to M22 at our institution and determine the effect on perioperative outcomes.

MATERIALS AND METHODS

We retrospectively reviewed our prostatectomy database from 2009-2012 to identify patients who underwent RALP with and without M22. Reasons for M22 were determined by review of operative reports. Comparisons were made using Chi-square analysis and independent t-tests for continuous data.

RESULTS

Of 579 patients identified from our database, 208 (36%) had a M22. Eighty-six (41%) patients had ≥ 2 documented reasons for M22. Adhesiolysis was the most common reason for M22 followed by large prostate and previous hernia mesh. Body mass index (BMI) (29.8 versus 28), prostate volume (53 g versus 44 g), operative time (259 minutes versus 234 minutes), and discharge from hospital with pelvic drain in place (6.7% versus 3%) were all significantly higher in the M22 group. Final pathological stage and positive margin rate were not increased in those with a M22. Complications were not different between those with and without M22.

CONCLUSION

The M22 code is associated with longer operative times, larger prostates, and higher BMI. Adverse effects on final pathological stage, margin status and complications were not found in those with M22. Many patients with a M22 have more than one reason documented as for the explanation of the modifier.

Current minimally invasive practice patterns among postgraduate urologists

PURPOSE

To determine laparoscopic and robotic surgical practice patterns among current postgraduate urologists.

MATERIALS AND METHODS

There were 9,095 electronic surveys sent to practicing urologists with e-mail addresses registered with the American Urological Association.

RESULTS

Responses were received from 864 (9.5%) urologists; 84% report that laparoscopic or robotic procedures are performed in their practice. The highest training obtained by the primary laparoscopist was fellowship (31%), residency (23%), or 2- to 3-day courses (22%). Eighty-six percent report performance of laparoscopic nephrectomy in their practice, and 71% consider it the standard of care. Sixty-six percent of practices have access to at least one robotic unit, and 9% plan on purchasing one within a year. Attitudes toward robotics are favorable, with 80% indicating that it will increase in volume and potential procedures. Thirty-one percent state that robot-assisted prostatectomy is standard of care, while 50% believe this procedure looks promising. Respondents think that optimal training in minimally invasive techniques is fellowships (23%), minifellowships (23%), or hands-on courses (23%). Twenty-nine percent think that they were trained adequately in laparoscopy and robotics from residency, and 62% believe residents should be able to perform most laparoscopic procedures on completion of residency.

CONCLUSIONS

The practice and availability of laparoscopic and robotic procedures have increased since previous evaluations. Opinions regarding these techniques are favorable and optimistic. As the field of urology continues to see a growing demand for minimally invasive procedures, training of postgraduate urologists and residents remains essential.

Active surveillance for prostate cancer in a veteran population

INTRODUCTION

Active surveillance for prostate cancer is a therapeutic option which is gaining more popularity. Implicit in this approach is careful monitoring to identify those with progression. Criteria for placing patients on active surveillance vary but generally include Gleason sum of 6 or less, prostate-specific antigen (PSA) less than 20, and a small volume of cancer in the biopsy specimen. We review our experience with active surveillance in a veteran population.

MATERIALS AND METHODS

We conducted a retrospective review of patients from the Kansas City Veterans Affairs (KCVA) who met the requirements for active surveillance (Gleason sum 6, percent of cancer in the specimen less than 20%, and PSA less than 20 ng/dL) between January 2004 and December 2009. In the patient group who chose active surveillance (AS), we evaluated the rates of compliance with the protocol mandated PSA's and the 1 year biopsy. In the patient group who declined AS and underwent immediate prostatectomy, we reviewed the final pathology for stage, Gleason grade, percent of tissue involved with cancer, margin status, nodal status, and rates of biochemical recurrence.

RESULTS

We identified 207 patients who met the requirements for active surveillance. Of these patients, 45 patients chose active surveillance while 66 patients underwent immediate radical prostatectomy at the KCVA. Of the 45 patients who went on active surveillance, all participants had at least one PSA drawn. However, only 24 (53.3%) patients complied with the protocol mandated prostate biopsy at 1 year. In the patient group who chose to undergo an immediate prostatectomy, 43 of 66 (65.2%) patients had upgrading of their Gleason score. This included 12 patients upgraded to Gleason sum 8 to 10 and two patients who were upstaged to T3 disease. Despite the significant upgrading, only two patients have had a biochemical recurrence at a median follow up of 30 months.

CONCLUSIONS

Active surveillance is a viable option for patients with low risk prostate cancer. However, this study raises concerns about compliance with recommendations for active surveillance in a VA population. Furthermore, there was a significant risk in this study of under-grading in patients who underwent immediate prostatectomy. This emphasizes the need for better education of patients who enter into active surveillance protocols regarding the need for compliance, the risks of progression, and the chance of under grading.

Survey of practicing urologists: robotic versus open radical prostatectomy

PURPOSE

The robotic assisted radical prostatectomy (RARP) has become the most common operative choice for localized prostate cancer. At our institution, we have also seen a substantial increase in the proportion of RARP. Possible patient factors may include marketing, increased Internet usage by patients, and patient-to-patient communication. We surveyed urologists from the central United States to determine possible surgeon factors for the popularity of the RARP.

MATERIALS AND METHODS

We mailed a survey to all urologists in the South Central Section of the American Urological Association. After demographic information was obtained, participants were asked to choose an operation for themselves based on two prostate cancer scenarios; low risk and high risk.

RESULTS

For the low risk prostate cancer scenario, 54.3% chose RARP while 32.9% chose a radical retropubic prostatectomy (RRP). In the high risk scenario, 32.3% chose a RARP while 58.8% chose the RRP. The top reasons for choosing robotics included decreased blood loss, better pain control, and visualization of the apex. The most popular reasons for an open operation included improved lymph node dissection, better tactile sensation, and easier operation for the surgeon. The two most important factors for choosing a particular operation were cancer control and the urologist performing the operation. Also, urologists favored the operative choice in which he or she performed.

CONCLUSION

Robotic assisted radical prostatectomy has become the favored operative approach for low risk prostate cancer. However, many urologists still feel an oncologic difference may exist between open and robotic surgery as evidenced by more urologists favoring an open approach for high risk prostate cancer.

Laparoscopic donor nephrectomy

Since it first was performed in 1995, laparoscopic donor nephrectomy (LDN) has grown to be the standard of care in most transplant centers in the United States. This article reviews the current indications, selection criteria, surgical approaches, outcomes, and complications of LDN.

Multi-institutional survey of laparoscopic ureterolysis for retroperitoneal fibrosis

OBJECTIVES

Medical therapy often fails to cure benign retroperitoneal fibrosis (RPF), necessitating a surgical approach. Preoperative and postoperative adjuvant medical therapy and the timing of surgical intervention are not well-established. We surveyed centers of laparoscopic excellence to determine the current practices in the treatment of RPF.

METHODS

Surveys were sent to all institutions with Endourological Society-recognized fellowships. The data collected were analyzed for trends in the treatment of RPF. Additional information was collected from participating institutions to better characterize the experience with laparoscopic ureterolysis and adjunctive medical management.

RESULTS

Of the surveys sent out, 17 completed surveys were returned (41%). A total of 73 patients had been treated for RPF. Most centers (13 of 17) used a conventional laparoscopic approach with rare conversion to hand assistance. The medical management of RPF was directed by urologists, rheumatologists, or other specialists in 59%, 24%, and 18% of institutions, respectively. Steroid therapy was administered preoperatively by 15 of 17 centers. Postoperatively, 10 of 17 centers continued treatment with steroids and/or cytotoxic agents. Eight institutions provided data on 46 renal units in the second part of the study. The success rate of laparoscopic ureterolysis per renal unit was 83% (38 of 46). No difference was seen in the outcomes of patients who received adjuvant medical therapy compared with those who did not (16 of 19 versus 22 of 27; P = 0.48) after a mean follow-up of 17.7 months.

CONCLUSIONS

The results of this study have shown that no uniform treatment algorithm exists for RPF at centers of laparoscopic excellence. Most institutions recommended an attempt at steroids followed by laparoscopic ureterolysis. Laparoscopic ureterolysis had a high success rate, and adjuvant medical therapy did not appear to contribute to the success rate.

Laparoscopic management of bilateral page kidneys

Hyper-reninemic hypertension as a result of renal compression is often referred to as a "Page" kidney. We present a case of a patient with bilateral Page kidneys from subcapsular hematomas as a complication of extracorporeal shock wave lithotripsy. After several attempts at percutaneous and laparoscopic drainage of the fluid collections, she was referred for definitive management with laparoscopic decortication and capsulotomy. Bilateral laparoscopic surgery was performed in a staged fashion, using a novel technique of radial incision inner capsulotomy, with resolution of the patient's hypertension. We report our technique and factors to consider in the management of Page kidney.

Robotic-Assisted Laparoscopic Ureteropyelostomy for Treatment of Prostatitis Secondary to Ectopic Ureteral Insertion of a Completely Duplicated Collecting System

Symptomatic presentation of a completely duplicated collecting system with upper-pole ectopic ureteral insertion is rare in the adult. We present a case of a 52-year-old man with recurrent prostatitis and hematuria secondary to an ectopic ureteral insertion from a left upper-pole moiety in a completely duplicated collecting system. He underwent a robot-assisted laparoscopic ureteropyelostomy with good results. We describe our technique in this unusual case.

Survey of residency training in laparoscopic and robotic surgery

PURPOSE

We determined the current status of residency training in laparoscopic and robotic surgery in the United States and Canada.

MATERIALS AND METHODS

A total of 1,188 surveys were sent via the Internet to all 1,056 current urology residents and 132 program directors with an Internet address registered with the American Urological Association.

RESULTS

Responses were received from 372 residents (35%) and 56 program directors (42%). Of respondents 47% reported greater than 100 laparoscopic procedures performed yearly by 1 (36%) or more (51%) faculty members. Robotic procedures were performed at 54% of the institutions, mainly consisting of prostatectomy and pyeloplasty. At all institutions laparoscopic radical nephrectomy was performed and those at 69% of the institutions believed that it is the gold standard for renal tumors today. Urologists were involved in 87% of adrenal surgeries and 54% of respondents believed that is the gold standard approach. However, only 35% of respondents had participated in laparoscopic adrenalectomy. Of respondents 36%, 42% and 17% reported that laparoscopic donor nephrectomy was performed by only urologists, only a nonurology transplant team and shared equally, respectively. Of respondents 41% planned on performing laparoscopic donor nephrectomy in the next year. Laparoscopic needle ablation renal surgery was done in 51% of the programs and percutaneous needle ablation was done in 63%. None of the respondents (0%) believed that it is the gold standard but 51% believed that ablative procedures look promising for renal tumors. Of respondents 39% had participated in robotic radical prostatectomy and 53% thought that it looked promising but was not the gold standard. Of respondents 31% believed that they will be performing robotic surgery after residency, 30% were unsure and 29% will not be using the robot. Overall 38% of residents thought that their laparoscopic experience was at least average or acceptable.

CONCLUSIONS

A large number of laparoscopic urological procedures are being performed at training institutions with robotic procedures being performed at 54% of respondent facilities. Residents are participating in most cases but only 38% consider their laparoscopic experience to be satisfactory. A need still exists for increased laparoscopic training for residents, which can be accomplished by expanding training facilities and increasing the number of faculty members performing laparoscopic procedures.

The influence of clinical and pathological stage discrepancy on cancer specific survival in patients treated for renal cell carcinoma

PURPOSE

We compared clinical and pathological staging in a contemporary, consecutive series of patients treated with partial or radical nephrectomy for renal cell carcinoma and we determined the effect of clinical and pathological stage discrepancy on outcomes.

MATERIALS AND METHODS

We collected retrospective clinical, pathological and survival data on 264 consecutive patients with clinical T1-3 renal cell carcinoma who were treated with laparoscopic or open partial or radical nephrectomy at a single institution from 1994 to 2003.

RESULTS

Pathological up staging occurred in 44 of 264 patients (17%) patients. Of 135 clinical T1 tumors 25 (18.5%) and 18 of 85 (21.2%) clinical T2 tumors were pathologically up staged. Patients with clinical T1 and T2 tumors were stratified into 2 groups, including those with the same clinical and pathological stage, and those with pathological up staging. Mean 5-year recurrence-free survival +/- SD for same stage vs pathologically up staged clinical T1 (84.3% +/- 4.4% vs 47.4% +/- 11.5%) and clinical T2 (80.0% +/- 6.8% vs 40.7% +/- 13.4%) tumors was significantly different (p < 0.0002). Five-year cancer specific survival for same stage vs pathologically up staged clinical T1 tumors was significantly different (98.5% +/- 1.5% vs 69.7% +/- 11.3%, p = 0.0005), while that for clinical T2 tumors approached clinical significance (90.9% +/- 5.0% vs 72.7% +/- 13.4%, p = 0.0501).

CONCLUSIONS

Stage discrepancy is common in surgically treated patients diagnosed with renal masses and it has a significant impact on clinical outcome. Implications of such clinical and pathological stage discrepancy should be considered when counseling patients and determining therapeutic approaches.

Effect of multisite radiofrequency ablation on porcine renal function

BACKGROUND AND PURPOSE

The acute and long-term effects of radiofrequency ablation (RFA) on kidney function have not been well studied. The functional change when RFA is used in combination with renal ischemia is likewise unknown. Our goal was to determine the change in renal function caused by various volumes of RFA on a porcine kidney model and the effect cold ischemia had on the results.

MATERIALS AND METHODS

Twenty-two female pigs with solitary kidneys underwent various volumes of RFA both with and without cold ischemia. Animals were divided into control, 10%, 15%, and 20% ablation of the total kidney volume. Measurements of creatinine were obtained for 2 weeks.

RESULTS

In the nonischemic group, the mean acute (day 1-3) creatinine changes in control, 10%, 15%, and 20% ablations were 0.6, 2.4, 1.7, and 2.6 mg/dL, respectively. In the cold-ischemia group, the mean acute creatinine changes were 0.85, 2.33, 3.3, and 3.75 mg/dL, respectively. Regression line analysis demonstrated a positive linear relationship in both groups. Fourteen-day mean creatinine changes for the nonischemic group were similar to those in the control animals and did not show a correlation with ablation volume. The mean creatinine changes at 14 days in the cold-ischemia group showed a positive linear correlation with ablation volume.

CONCLUSIONS

The volume of RFA correlates with an acute change in renal function in the porcine model for both nonischemic and cold-ischemia groups. This study may help predict the extent of acute renal dysfunction in patients undergoing RFA for large or multiple renal masses. These results also suggest renal function may recover after nonischemic RFA.

Hand-assisted laparoscopic nephrectomy for renal masses >9.5 cm: Series comparison with open radical nephrectomy

OBJECTIVE

To assess the feasibility of hand-assisted laparoscopic nephrectomy (HALN) for large renal masses (stage T2, mean size 9.7 cm) and compare outcomes with a similar cohort undergoing open radical nephrectomy (ORN).

METHODS

A nonrandomized comparison of 19 consecutive patients who underwent nephrectomy for renal masses >or=7 cm was performed. The HALN group was compared to the ORN group regarding demographic parameters and perioperative data, including blood loss, operating time, narcotic usage, hematocrit change, return to standard oral intake, length of hospital stay, and complications. Data collected prospectively and statistics used 2-tailed t-test analysis.

RESULTS

Patients underwent either ORN (mean tumor size 12.3 cm) or HALN (mean tumor size 9.7cm). Tumors up to 14 cm (n = 2) and pT3b, with renal vein thrombosis (n = 2), could be safely excised with HALN. There were no differences between the HALN and ORN groups regarding any demographic parameter. Blood loss, operating time, length of stay, parenteral narcotic use, and time to tolerating regular diet were all less statistically significant in the HALN group as compared to the ORN group (P < 0.05). Tumors >15 cm necessitated ORN.

CONCLUSIONS

HALN is technically feasible even for tumors with mean size >9.5 cm. There is a significant advantage to HALN over ORN regarding the intraoperative and postoperative morbidity. Tumors >or=15 cm should, in most cases, be performed with an open approach.

Contrast-enhanced ultrasound evaluation of radiofrequency ablation of the kidney: reliable imaging of the thermolesion

BACKGROUND AND PURPOSE

Radiofrequency ablation (RFA) is limited by the inability to monitor progression of the thermal lesion. Contrast-enhanced ultrasonography (CEUS) imaging has considerable potential as a monitoring modality for RFA. We report our experience using CEUS to evaluate the lesion produced by RFA in a porcine model.

MATERIALS AND METHODS

Five pigs underwent laparoscopic RFA twice, spaced by a 1-week interval. Post- RFA ultrasound imaging was performed transcutaneously immediately after ablation. The kidneys were assessed for a contrast void corresponding to the ablated tissue. The kidneys were then harvested and the gross RFA lesions measured to compare lesion size with that measured using CEUS.

RESULTS

A clear lesion was identified at the site of each RFA application. As measured by CEUS, the acute lesions averaged 1.8 +/- 0.4, 1.7 +/- 0.4, and 1.8 +/- 0.3 cm in length, height, and width, respectively, compared with 2.0 +/- 0.5, 1.8 +/- 0.4, and 1.9 +/- 0.3 cm, respectively, by measurement in the gross specimen (P = 0.33, 0.13, and 0.44, respectively). At 1 week, the CEUS-measured dimensions of the lesions were 2.7 +/- 0.5, 2.6 +/- 0.6, and 2.6 +/- 0.6 cm, and the gross measurements of the lesion were 2.7 +/- 0.4, 2.7 +/- 0.9, and 2.6 +/- 0.4 cm (P = 0.75, 0.92, and 0.40, respectively).

CONCLUSIONS

Contrast-enhanced ultrasonography appears to be an accurate modality for immediate monitoring of RFA defects. Further study is necessary to assess the clinical utility of CEUS for monitoring RFA of small renal lesions.

HAND ASSISTED LAPAROSCOPIC CYSTECTOMY WITH MINILAPAROTOMY ILEAL CONDUIT: SERIES REPORT AND COMPARISON WITH OPEN CYSTECTOMY

PURPOSE

To achieve less patient morbidity our initial experience with hand assisted laparoscopic (HAL) cystectomy was compared with our results of open cystectomy with similar urinary diversion.

MATERIALS AND METHODS

During 18 months 36 cystectomies were performed, including 20 with open continent diversion. A prospective, nonrandomized comparison of the remaining 16 consecutive cystectomies with ileal conduit diversion (hand assisted laparoscopic cystectomy and open cystectomy in 8 cases each) was performed. Of the 16 cystectomies 13 were performed for muscle invasive bladder cancer. Standard parameters were compared concerning patient operative and postoperative courses using statistical analysis with the 2-tailed t test. A novel surgical technique for completing these HAL procedures is described and compared to standard open cystectomy and ileal conduit diversion.

RESULTS

A total of 16 patients successfully underwent open (8) and HAL (8) cystectomy with an ileal conduit. Mean estimated blood loss in the HAL and open groups was 637 and 957 cc, respectively (p = 0.23). The mean postoperative parenteral analgesia administered was 31 mg in the HAL group vs 149 mg in the open group (p = 0.01). The HAL and open groups had a mean length of stay of 6.4 vs 9.8 days (p = 0.06). Mean operative time did not differ significantly between the HAL and open groups (403 and 420 minutes, respectively). Regular diet was resumed at 4.5 days in the HAL group vs 7.9 days in the open group (p = 0.05). Hospital length of stay was 6.4 vs 9 days for HAL vs open cases (p = 0.06).

CONCLUSIONS

To our knowledge this represents the first reported series of patients undergoing HAL cystectomy with urinary diversion. HAL cystectomy with an ileal conduit appears to have less estimated blood loss and postoperative analgesic requirements, shorter length of stay and earlier return of bowel function than open cystectomy. Oncological efficacy was preserved in the short term.

Ureteral replacement using small-intestinal submucosa and a collagen inhibitor in a porcine model

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.

Changing Management of Organ-Confined Renal Masses

BACKGROUND AND PURPOSE

Rapid evolution of laparoscopic and ablative techniques is changing the approach to renal masses. We evaluated our approach to managing renal masses in light of newly available technology.

PATIENTS AND METHODS

The records for all patients who underwent treatment for a renal mass between January 2000 and July 2002 at UT Southwestern Medical Center were reviewed for patient demographics, operative details, and pathology results. There were 180 patients with 190 masses. Of the 190 masses, 97 were <4 cm, 47 were between 4 and 7 cm, and 46 were >7 cm.

RESULTS

Most tumors >7 cm were managed with open radical nephrectomy (RN). For patients with masses between 4 and 7 cm, the majority were treated with laparoscopic RN, while 21% were treated by open partial nephrectomy (PN). Tumors <4 cm were treated with the widest variety of approaches. Open PN was the most commonly utilized, followed by laparoscopic RN and percutaneous ablation. The number of laparoscopic and percutaneous ablative procedures increased significantly with time, from none in the first year to 13% (7/55) and 29% (16/55) in the last year, respectively. Benign pathology was found in 20%, 17%, and none of lesions <4, 4 to 7, and >7 cm, respectively.

CONCLUSIONS

The addition of laparoscopy and ablative technologies has increased the treatment options for patients with renal masses. We propose a treatment algorithm that incorporates ablative technologies and favors parenchyma-sparing approaches for small lesions.

Histopathology of surgically managed renal tumors: analysis of a contemporary series

OBJECTIVES

To review the pathologic findings of a contemporary series of surgically treated renal tumors suspicious for malignancy to assess the frequency of benign disease in the modern era. The extensive application of modern imaging techniques has led to an increase in the number of incidentally discovered solid renal masses, many of which are small. A significant proportion of small renal tumors are benign or are low-grade malignancies.

METHODS

The records of all patients at our institution who underwent treatment for a renal mass suspicious for malignancy between November 1999 and July 2002 were retrospectively reviewed.

RESULTS

A total of 173 patients with 186 renal tumors had pathologic information available for analysis. Of the 186 tumors, 48% were discovered incidentally. For masses 4 cm or less, the percentage of incidentally discovered tumors increased to 58%. The pathologic evaluation demonstrated malignancy in 160 (86%) and benignity in 26 (14%) overall. For tumors 4 cm or less, 18 (20%) of 90 were benign; for tumors between 4 and 7 cm, 8 (17%) of 47 benign. No tumors greater than 7 cm were benign. All renal cell carcinomas less than 2 cm in size were Fuhrman grade 1 or 2.

CONCLUSIONS

Small renal tumors, many of which are incidentally discovered, are often benign or are low-grade malignancies. For tumors 4 cm or less, the frequency of benign pathologic findings is greater than previously quoted in published reports. As a result, we recommend parenchymal-sparing approaches whenever possible.

Laparoscopic donor nephrectomy at a low volume living donor transplant center: successful outcomes can be expected

PURPOSE

Concern has been raised about possible increased morbidity associated with laparoscopic donor nephrectomy (LDN) during the learning curve of the procedure and at centers with a low volume of living donors. We evaluated the safety and success of LDN at a low volume living donor transplant center with a skilled laparoscopic urologist and experienced renal transplant team.

MATERIALS AND METHODS

We reviewed the records of all patients who underwent LDN at our institution. A single surgeon skilled in laparoscopy (JAC) performed all LDNs. Patient demographics, operative reports, complications and recipient outcomes were evaluated.

RESULTS

A total of 17 LDNs were performed between January 2000 and September 2002. There was 1 elective conversion to an open procedure for kidney harvest due to complex hilar anatomy. Only 1 minor complication occurred (wound seroma) and 1 donor had creatinine persistently elevated to 1.9 mg/dl (normal 0.6 to 1.2). Mean operating room time, estimated blood loss and hospital stay were 250 minutes, 188 ml and 2.5 days, respectively. Recipient creatinine had a nadir mean of 1.2 mg/dl and a 90-day postoperative mean of 1.6 mg/dl. One recipient eventually lost the graft due to recurrent disease.

CONCLUSIONS

LDN can be performed safely and efficiently at low volume transplant centers with a skilled laparoscopist and experienced renal transplant team. Laparoscopic skills developed during similar procedures, such as laparoscopic radical and partial nephrectomy, minimize the learning curve and morbidity of LDN to produce results consistent with those in the published literature.

Cost comparison of hand assisted laparoscopic nephrectomy and open nephrectomy: analysis of individual parameters

PURPOSE

Hand assisted laparoscopic nephrectomy (HAL) is an effective approach to nephrectomy that is less morbid than open nephrectomy (ON). In response to budgetary pressure at our large county hospital we reviewed the published experience and identified the cost components of HAL that could be targeted to decrease procedure cost.

MATERIALS AND METHODS

A comprehensive literature review of HAL and ON was performed and certain parameters were abstracted, including operative (OR) time, operative equipment and hospital stay (LOS). Using these data the projected overall cost and individual cost centers at our institution for HAL and ON were compared. Decision tree analysis models were devised to estimate the cost of each treatment using computer software. One and 2-way sensitivity analyses were performed to evaluate the effect of individual treatment variables on overall cost.

RESULTS

The literature showed 6 and 9 reports on 127 and 419 patients for ON and HAL, respectively. LOS was 5 and 3 days for ON and HAL, respectively. OR time was 169 and 204 minutes for ON and HAL, respectively. Based on a review of the costs at our institution ON was a less costly procedure by $205 ($6,882 vs $7,087 US dollars). 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, HAL demonstrated a cost advantage for LOS. One-way sensitivity analyses showed that HAL was less costly if HAL OR time was less than 184 minutes, LOS following HAL was less than 2.5 days or HAL OR supply costs were less than $718 US dollars. Two-way sensitivity analysis demonstrated that HAL was cost advantageous if performed in less than 3 hours and the patient was discharged home within 3 postoperative days.

CONCLUSIONS

Primary cost variables for nephrectomy include OR time, LOS stay and equipment cost. Using published data and decision tree analysis ON is slightly less costly by $205 US dollars than HAL at our institution. However, HAL can be more cost-effective than ON when OR time and LOS are low. Our model identifies several measures that can be used at any institution to render HAL economically superior to ON.

Nephrectomy after radiofrequency ablation-induced ureteropelvic junction obstruction: potential complication and long-term assessment of ablation adequacy

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.