The Impact of Distraction on Laparoscopic Skills in Veterinary Medical Students.

OBJECTIVE: To investigate the impact of distraction on the performance of a simulator-based laparoscopic task in veterinary students. STUDY DESIGN: Prospective, randomized trial. SAMPLE POPULATION: Years 1-4 veterinary students (n=41). METHODS: Participants repeated a simulated laparoscopic peg transfer task to eliminate any learning effects and were subsequently randomized to receive either a cognitive (double-digit addition questions, n=21) or sensory distraction (dogs barking and anesthesia monitor alerts, n=20). The laparoscopic task scores were compared between baseline and in the presence and absence of each distraction. The number of addition questions attempted, and the number of questions answered correctly in 1 minute were compared between baseline and during a concurrent laparoscopic task. RESULTS: Baseline laparoscopic task scores were not significantly different between groups (P=.09). Laparoscopic task scores were significantly lower than baseline when performed with the cognitive distraction (P<.001) and significantly higher than baseline when performed with the sensory distraction (P=.005). Participants undergoing cognitive distraction attempted significantly fewer addition questions (P<.001) and answered significantly fewer addition questions correctly (P<.001) when a concurrent laparoscopic task was performed. CONCLUSION: Cognitive distraction had a negative impact on the performance of a laparoscopic task in this cohort of veterinary students, whereas sensory distraction had a positive effect.

The use of internal stents in chronic ureteral obstruction.

PURPOSE: Despite the lack of a well delineated definition, chronic ureteral obstruction imposes significant quality of life loss, increased pathological morbidity and risk of mortality as well as substantial economic burden. Ureteral stenting serves as an important therapeutic option to alleviate obstruction. Thus, we assessed the recently published literature on chronic ureteral obstruction; treatment options; types, benefits and shortcomings of current ureteral stents; as well as outcomes and complications of chronic ureteral stenting, with the goal of providing concise management guidelines. MATERIALS AND METHODS: A systemic literature review was performed on Embase™, PubMed®, Cochrane Controlled Trials Register and Google Scholar™ on ureteral obstruction and internal ureteral stents. Relevant reviews, original research articles and their cited references were examined, and a synopsis of original data was generated on a clinically oriented basis. RESULTS: Chronic ureteral obstruction can be classified into compression that is either intrinsic or extrinsic to the ureteral wall, or obstruction that is of a benign or malignant origin. Patients with malignant ureteral obstruction generally have a poor prognosis and are often difficult to treat. The aim of stenting is to adequately drain the upper urinary tracts while minimizing hospitalization and the negative impact on quality of life. Facing the challenge of chronic ureteral obstruction, novel stents with new compositions, materials, coatings and designs have been developed. Metallic stents are emerging as efficacious and financially viable alternatives. Early stent related complications include iatrogenic injury, stent migration or patient discomfort, while late complications include infection, difficulties with stent exchange, hardware malfunction, infection and stent encrustation. CONCLUSIONS: Stenting in chronic ureteral obstruction is a complex and challenging problem. Much work is being done in this area and many options are being explored.

Risk Factors for Postoperative Complications of Percutaneous Nephrolithotomy at a Tertiary Referral Center.

PURPOSE: We sought to describe and evaluate the complications related to percutaneous nephrolithotomy and identify risk factors of morbidity according to the modified Clavien scoring system. We also sought to specify which perioperative factors are associated with minor and major complications. MATERIALS AND METHODS: We retrospectively analyzed data on patients who underwent percutaneous nephrolithotomy from 1990 to 2013. Descriptive statistics were used to analyze patient characteristics, medical comorbidities and perioperative features. Complications were categorized according to the Clavien score for percutaneous nephrolithotomy. The Mann-Whitney and Fisher exact tests were used as appropriate. Logistic regression analysis was performed to look for prognostic factors associated with major complications. RESULTS: A total of 2,318 surgeries were evaluated. Mean age of the population was 53.7 years. The stone-free rate at hospital discharge was 81.6%. The overall complication rate was 18.3%. Two deaths occurred. Patients with any postoperative complications were older, had more comorbidities, were more likely to have staghorn calculi and had longer operative time and hospital stay on univariate analysis (p<0.05). Age 55 years or older and upper pole access were independent predictors of major complications on multivariate analysis. Other factors such as a history of urinary tract infections, body mass index, stone composition, previous percutaneous nephrolithotomy and multiple tracts were not associated with a major complication. CONCLUSIONS: At our center percutaneous nephrolithotomy is an excellent option for complex kidney stone management with a low overall complication rate. Older patient age and upper pole access are significantly associated with an increased risk of a major complication.

The Post-Ureteroscopic Lesion Scale (PULS): a multicenter video-based evaluation of inter-rater reliability.

PURPOSE: The Post-Ureteroscopic Lesion Scale (PULS) offers a simple grading system for the description of ureteral lesions after ureteroscopy. In this article, we present the results of a video-based multicenter evaluation of the inter-rater reliability of clinically important PULS grades 0-3. METHODS: Video sequences at the end of ureteroscopy (final passage) were recorded for 100 consecutive patients at a single institution and assessed by experienced urologists (n = 20) and senior residents (n = 17) at 19 international centers. The cohort included only patients with lesions grades 0-3 (with grades 2 and 3 subsumed as 2 + since distinction is defined by an extravasation of contrast medium in fluoroscopy). The gradings were evaluated for inter-rater reliability and in terms of simplicity, validity, comprehensibility, reproducibility, and usefulness. RESULTS: Overall, inter-rater reliability was high (Kendall's W = 0.69, p < 0.001) and was comparable between specialists (Kendall's W = 0.69, p < 0.001) and residents (Kendall's W = 0.71, p < 0.001). The matched ratings showed grade 0 in 43.0 % of patients and grades 1 or 2 + in 44.0 and 13.0 % of patients, respectively. Results of the questionnaires indicated a high degree of acceptance, with an overall rating of 1.76 (1.64-1.93 for different items, scale 1-6). CONCLUSIONS: Inter-rater reliability of the endoscopically assessable PULS was high among urologists with different levels of experience in different countries worldwide. The validated PULS system may be used for standardized reporting of ureteral lesions/injuries after ureteroscopy. In addition, PULS will enable more selective standardization of indications for postoperative DJ stenting based on the randomized controlled trials.

Standardizing the reporting of percutaneous nephrolithotomy complications.

Accurate reporting of complications is an essential component to critical appraisal and innovation in surgery and specifically with percutaneous nephrolithotomy (PCNL). We review the evolution of complication reporting for PCNL and suggest future directions for innovation. A selective review was carried out using Pubmed. Key search terms and their combinations included percutaneous, anatrophic, nephrolithotomy, PCNL, complications, Clavien, Martin score, bleeding, bowel injury, perforation, fever, sepsis. The references from relevant papers and reviews as well as AUA and EAU guidelines were also scanned for inclusion. PCNL has become the procedure of choice for large renal stones owing to decreased morbidity over alternative procedures. Both common and rare complications have been described in large case series, small randomized controlled trials, and case reports in an unstandardized form. Although these reports have provided an informative starting point, a standardized complication reporting methodology is necessary to enable appropriate comparisons between institutions, time periods, or innovations in technique. The Clavien-Dindo grading system has become widely accepted in urology and has facilitated the study of PCNL complications. Future research should focus on adaptions of this system to render it more comprehensive and applicable to PCNL.

Multi-site microbiota alteration is a hallmark of kidney stone formation.

BACKGROUND: Inquiry of microbiota involvement in kidney stone disease (KSD) has largely focussed on potential oxalate handling abilities by gut bacteria and the increased association with antibiotic exposure. By systematically comparing the gut, urinary, and oral microbiota of 83 stone formers (SF) and 30 healthy controls (HC), we provide a unified assessment of the bacterial contribution to KSD. RESULTS: Amplicon and shotgun metagenomic sequencing approaches were consistent in identifying multi-site microbiota disturbances in SF relative to HC. Biomarker taxa, reduced taxonomic and functional diversity, functional replacement of core bioenergetic pathways with virulence-associated gene markers, and community network collapse defined SF, but differences between cohorts did not extend to oxalate metabolism. CONCLUSIONS: We conclude that multi-site microbiota alteration is a hallmark of SF, and KSD treatment should consider microbial functional restoration and the avoidance of aberrant modulators such as poor diet and antibiotics where applicable to prevent stone recurrence. Video Abstract.

The CROES percutaneous nephrolithotomy global study: the influence of body mass index on outcome.

PURPOSE: In addition to more commonly forming stones, obese patients present a number of challenges when undergoing percutaneous nephrolithotomy. We evaluated percutaneous nephrolithotomy outcomes in 3,709 patients stratified by body mass index. MATERIALS AND METHODS: A prospective database administered by CROES (Clinical Research Office of the Endourological Society) captured data on 5,803 patients treated with percutaneous nephrolithotomy between November 2007 and December 2009. Patients with known solitary kidney, previous percutaneous nephrolithotomy and congenital abnormalities were excluded from analysis. For statistical analysis patients were categorized as normal weight--body mass index 18.5 to 25 kg/m(2), overweight--25 to 30, obese--30 to 40 and super obese--greater than 40. RESULTS: During the study period 5,803 patients underwent percutaneous nephrolithotomy, of whom 3,709 met the inclusion criteria. As expected, obesity was associated with significantly higher rates of comorbid conditions and anticoagulant use (p < 0.001). Operative time was significantly longer in obese patients and use of a balloon device for tract dilation was more common (each p < 0.001). The stone-free rate decreased with obesity (p = 0.009), corresponding to a significantly higher re-treatment rate in this group (p < 0.001). No difference was seen in length of stay or the transfusion rate. No significant difference was seen in the overall complication rate among the 4 groups (p = 0.707). CONCLUSIONS: Percutaneous nephrolithotomy may be done safely in obese patients, although with a longer operative time, an inferior stone-free rate and a higher re-intervention rate.

The use of triclosan eluting stents effectively reduces ureteral stent symptoms: a prospective randomized trial.

UNLABELLED: What's known on the subject? and What does the study add? Infection, encrustation and ureteral-stent-related symptoms (USRS) including pain, urgency and frequency are all major problems associated with stent use. No current ureteral stent or exogenously applied therapy adequately deals with these problems and antibiotic use is ineffective once a bacterial biofilm forms on the device. Triclosan is a broad spectrum antibacterial agent widely used in numerous healthcare products and has been previously shown to reduce inflammation on the skin and in the oral cavity. This study tested a triclosan-impregnated ureteral stent for its ability to reduce infection, encrustation and USRS. This study shows that while a triclosan-impregnated ureteral stent cannot reduce infection rates alone compared with antibiotic use, the stent can reduce several USRS including pain during indwelling. This study suggests that the triclosan eluting stent may have a role in treating patients, perhaps in combination with standard antibiotic therapy. OBJECTIVE: To evaluate the capacity of triclosan-loaded ureteral stents to reduce stent-associated bacterial attachment, biofilm formation and encrustation, thereby potentially reducing infection development and other device-related sequelae. PATIENTS AND METHODS: Twenty subjects requiring short-term stenting (7-15 days) were randomized to receive either a Percuflex Plus(®) non-eluting stent (control) or a Triumph(®) triclosan eluting stent. Control-stented subjects received 3 days of levofloxacin prophylaxis (500 mg once daily) while Triumph(®)-stented subjects did not. All subjects were assessed for positive urine and stent cultures, stent biofilm development and encrustation. Following device removal, each subject completed an analogue-scale symptom assessment questionnaire. RESULTS: Ureteral stenting was performed after nine ureteroscopic and one extracorporeal shock wave lithotripsy procedure in the control group and eight ureteroscopic and two shock wave lithotripsy procedures in the triclosan group. No significant differences were observed for culture, biofilm and encrustation between the two groups. Subjects in the triclosan group reported significant reductions in lower flank pain scores during activity (58.1% reduction, P = 0.017) and urination (42.6%, P = 0.041), abdominal pain during activity (42.1%, P = 0.042) and urethral pain during urination (31.7%, P = 0.049). CONCLUSIONS: In this study, the use of the Triumph(®) triclosan eluting stent had no marked impact on biofilm formation, encrustation or infection development in short-term stented patients. The Triumph(®) device led to significant reductions in several common ureteral-stent-related symptoms, supporting its use in this patient population.

Randomized controlled, multicentre clinical trial comparing a dual-probe ultrasonic lithotrite with a single-probe lithotrite for percutaneous nephrolithotomy.

OBJECTIVES: • To compare the Cyberwand (Gyrus/ACMI, Southborough, MA, USA), a dual-probe ultrasonic lithotrite, with a single-probe ultrasonic lithotrite. • The Cyberwand incorporates coaxial high- and low-frequency ultrasonic probes that work synergistically. PATIENTS AND METHODS: • An institutional review board-approved, multicentre, randomized controlled trial to compare the Cyberwand to the Olympus LUS-II (Olympus America, Inc., Melville, NY, USA) single-probe lithotrite was performed. • Patients undergoing a percutaneous nephrolithotomy (PCNL) with a target stone > 2 cm in diameter were eligible for the study. • The primary outcome was the time to removal of the targeted stone. RESULTS: • A total of 57 PCNLs were performed after randomization: 25 Cyberwand and 32 LUS-II. • There was no difference (P > 0.05) observed between the two devices for target stone surface area (Cyberwand 526.6 cm³ vs LUS-II 540.1 cm³), time to clearance of target stone (Cyberwand 15.8 min vs LUS-II 14.2 min) and target stone clearance rate (Cyberwand 61.9 mm²/min vs LUS-II 75.8 mm²/min). • Of the patients with stone analysis, hard stones (calcium oxalate monohydrate, brushite and cystine) were noted in 14 (56.0%) of the 25 Cyberwand and 18 (62.1%) of the 29 LUS-II patients. • Fifteen of the 25 (60.0%) Cyberwand and 20 of the 32 (62.5%) LUS-II patients were stone-free after the initial PCNL. • Those patients not rendered stone-free went on to receive a secondary PCNL. • Device malfunction occurred in eight of 25(32.0%) Cyberwand and five of 32 (15.6%) LUS II patients. • Complications were similar in both treatment groups. CONCLUSION: • No appreciable difference between the dual-probe Cyberwand and the standard ultrasonic Olympus LUS-II lithotrites can be identified.

A novel drug eluting ureteral stent: a prospective, randomized, multicenter clinical trial to evaluate the safety and effectiveness of a ketorolac loaded ureteral stent.

PURPOSE: We evaluated the short-term safety and efficacy of a ketorolac loaded ureteral stent compared to a standard stent (control). MATERIALS AND METHODS: In this prospective, multicenter, double-blind study patients were randomized 1:1 to ketorolac loaded or control stents after ureteroscopy. The primary end point was an intervention for pain defined as unscheduled physician contact, change in pain medication or early stent removal. Secondary end points included medication use and pain visual analog score. A total of 20 patients underwent serum safety testing for ketorolac levels. RESULTS: None of the safety cohort had detectable serum ketorolac levels. Among the 276 patients there was no difference in primary (9.0% ketorolac loaded vs 7.0% control, p = 0.66) or secondary (22.6% ketorolac loaded vs 25.2% control, p = 0.67) intervention rates. Mean pain pill count at day 3 was lower in the ketorolac loaded stent group than in the control group (p <0.05). A higher number (p = 0.057) of patients with ketorolac loaded (32%) stents used no or limited pain medications compared to controls (22%). A higher number of male patients with ketorolac loaded stents used no pain medication on days 3 and 4 compared to female patients with ketorolac loaded stents, and male and female control patients (p <0.05). CONCLUSIONS: The overall safety of the ketorolac loaded stent was confirmed. Although there was no significant difference in primary or secondary intervention rates, a trend toward a treatment benefit was noted for patients receiving drug loaded stents. Specifically young male patients appeared to require less pain medication when the ketorolac loaded stent was used. Future studies with higher drug concentrations or alternative drug eluting stents may prove beneficial.

Novel in vitro model for studying ureteric stent-induced cell injury.

OBJECTIVE: To develop a novel in vitro model for the study of bladder and kidney epithelial cell injury akin to stent movement, as ureteric stents are associated with urinary tract complications that can significantly add to patient morbidity. These sequelae may be linked to inflammation triggered by stent-mediated mechanical injury to the urinary tract. MATERIALS AND METHODS: T24 bladder and A498 kidney cell line monolayers were damaged mechanically by segments of either Percuflex Plus (PP) or Triumph (triclosan-eluting) stents (both from Boston Scientific Corporation Inc. Natick, MA, USA) and the resulting expression profiles of several pro-inflammatory cytokines and growth factors were analysed. RESULTS: After control injury using the PP stent, supernatants of both cell lines had significantly increased levels of interleukin (IL)-6, IL-8, basic fibroblast growth factor and platelet-derived growth factor BB, and A498 cells also had increased tumour necrosis factor alpha. In almost all cases, the presence of triclosan within the media abrogated the pro-inflammatory cytokine increases, while its effects on growth factors varied. CONCLUSION: This study suggests that stent-related symptoms in the bladder and kidney may be partially due to a local inflammatory response to epithelial damage caused by the presence and movement of the stent. Future stent design should take these inflammatory responses, with respect to physical injury, into consideration, using either more biocompatible materials or anti-inflammatory compounds such as triclosan.

Current status of ureteral stent technologies: comfort and antimicrobial resistance.

The placement of a ureteral stent is one of the most commonly performed urologic procedures. Indwelling ureteral stents are often accompanied by significant patient morbidity, including lower urinary tract symptoms, flank pain, and urinary tract infections. This article reviews the current state of ureteral stent technology developed to address the problem of stent discomfort and infection.

Stone Burden Measurement by 3D Reconstruction on Noncontrast Computed Tomography Is Not a More Accurate Predictor of Stone-Free Rate After Percutaneous Nephrolithotomy Than 2D Stone Burden Measurements.

Purpose: Stone burden has been reported as an independent predictor of stone-free rate after percutaneous nephrolithotomy (PCNL); however no consensus exists on a standardized method for measuring stone burden. Recently, stone volume has been advocated as the most accurate means of measuring stone burden. We aimed to compare different measuring methods of stone burden and to identify the predictive value of each for outcomes after PCNL. Materials and Methods: We performed a retrospective review of a prospective database of patients who underwent PCNL between 2006 and 2013. A preoperative CT and postoperative imaging at discharge were necessary for eligibility. Stone burden was assessed through four different ways on CT images: (1) cumulative stone diameter; (2) estimated SA (surface area) calculated as longest × orthogonal diameter × π/4; (3) manual outline of stone and computer SA calculation; and (4) automated 3D volume calculation using specific software. Primary outcome was stone-free status (SFS) at discharge. Secondary outcomes included operative time and the need for an ancillary procedure. Regression analysis and receiver operating characteristic curve analysis were used to evaluate the predictive value of each method. Results: Of 313 included patients, 69.6% were stone free at discharge. All measures of stone burden were independent predictors of SFS [OR and 95% CI of 1.027 (1.014, 1.040), 1.481 (1.180, 1.858), 1.736 (1.266, 2.380), and 1.311 (1.127, 1.526), respectively] and demonstrated similar predictive accuracy (area under the curve = 0.630, 0.630, 0.627, and 0.638, respectively). Stone burden by any measure was an independent predictor of operative time and secondary procedure. Conclusions: We demonstrated that measuring stone burden by manual outline or automated 3D volume on reformatted CT images had no added value compared with orthogonal measurement for predicting outcomes after PCNL.

Ureteral Stent Microbiota Is Associated with Patient Comorbidities but Not Antibiotic Exposure.

Ureteral stents are commonly used to prevent urinary obstruction but can become colonized by bacteria and encrusted, leading to clinical complications. Despite recent discovery and characterization of the healthy urinary microbiota, stent-associated bacteria and their impact on encrustation are largely underexplored. We profile the microbiota of patients with typical short-term stents, as well as over 30 atypical cases (all with paired mid-stream urine) from 241 patients. Indwelling time, age, and various patient comorbidities correlate with alterations to the stent microbiota composition, whereas antibiotic exposure, urinary tract infection (UTI), and stent placement method do not. The stent microbiota most likely originates from adhesion of resident urinary microbes but subsequently diverges to a distinct, reproducible population, thereby negating the urine as a biomarker for stent encrustation or microbiota. Urological practice should reconsider standalone prophylactic antibiotics in favor of tailored therapies based on patient comorbidities in efforts to minimize bacterial burden, encrustation, and complications of ureteral stents.

Outcomes of Conservative Management of Splenic Injury Incurred During Percutaneous Nephrolithotomy.

Purpose: Splenic injury is a rare complication after left-sided percutaneous nephrolithotomy (PCNL). Although initial observation is often espoused, the natural history of nonoperative conservative management is not well established and the implications of splenic injury are not fully defined in this context. We sought to describe outcomes of conservative management of splenic injury incurred at PCNL. Patients and Methods: We performed a multi-institutional retrospective review of individual patients who underwent PCNL complicated by trans-splenic nephrostomy access injury. Demographic info, intraoperative data, management strategies, and outcomes were reviewed. Results: Nine patients suffered splenic injury after left PCNL. All patients had supracostal upper pole access under fluoroscopic guidance. Splenic injury was identified by computed tomography (CT) in the eight of nine (89%) who had imaging on first postoperative day. All eight patients were managed conservatively with nephrostomy dwell time of 2-21 days, one of whom (11%) required blood transfusion. The remaining patient (11%)-who had tubeless PCNL without postoperative imaging presented 5 days postoperatively with a delayed bleed and underwent emergent splenectomy. Seven of the nine (78%) were managed nonoperatively and without need for transfusion or embolization. Conclusion: The majority of patients incurring splenic injury during PCNL can be managed conservatively with maintenance of nephrostomy tube for ≥2 days. Consequences of unrecognized splenic injury may include splenic bleed and may prompt transfusion and/or splenectomy, underscoring role of routine postoperative CT to allow timely diagnosis, particularly in those undergoing upper pole supracostal left-sided percutaneous renal access.

Celebrating 75 years.

INTRODUCTION: Following the introduction of shock wave lithotripsy (SWL), ureteroscopy (URS), and percutaneous nephrolithotomy (PCNL), the subspecialty of endourology was born in the late 1970s. The purpose of this study was to report milestones in Canadian endourology, highlighting Canada's contributions to the field. METHODS: A review of the literature was performed from the late 1970s to the present. The literature review included bibliographic and digital resources. Additionally, records and recollections by various individuals were used, including some who were directly involved. RESULTS: Endourology was born in Canada when SWL, URS, and PCNL emerged as minimally invasive treatment options for stones in the early to mid-1980s. According to our research, the first PCNL was performed at the University of Toronto in 1981. Dr. Joachim Burhenne, a Harvard-trained radiologist from Germany, first used extracorporeal SWL in Canada at the University of British Columbia (UBC) for the treatment of biliary stones. Treatment for urinary tract stones followed at UBC and Dalhousie University. The first worldwide use of the holmium laser for lithotripsy of urinary tract calculi took place at the University of Western Ontario. Other endourology milestones in Canada include the formation of the Canadian Endourology Group and the emergence of the Endourological Society-accredited fellowship programs at the University of Toronto and Western University in the 1990s. Canada hosted the 21st and 35th World Congress of Endourology and Shock Wave Lithotripsy annual meeting in Montreal and Vancouver, respectively. CONCLUSIONS: Canadian urologists have led many advances in SWL, URS, and PCNL over the past four decades and, for a relatively small community, have made significant contributions to the field. Through the training of the next generation of endourologists at Canadian institutions, the future of endourology in Canada is bright.

Eliminating biofilm from ureteral stents: the Holy Grail.

PURPOSE OF REVIEW: Biofilms continue to be a major limiting factor in the long-term use of ureteral stents, promoting the development of chronic infections and antibiotic resistance and encrustation. Apart from stent removal in conjunction with antibiotic therapy, there is currently no treatment proven successful for completely eradicating a biofilm-related infection, highlighting the need for continued research in this area. RECENT FINDINGS: Research continues to focus mainly on biofilm prevention, specifically the development of novel coatings comprising antibacterial, antifouling or bacterial signalling compounds. Notably, all three strategies have generated candidate coatings showing recent success both in vitro and in vivo. SUMMARY: Despite the current lack of a completely biofilm-resistant device, coating or treatment strategy, continued research into the causation of bacterial biofilm formation and the continued development of novel antibacterial, antifouling and antibiofilm compounds is promising. Future work should be aimed at more rigorous testing of candidate coatings from both physical and bacterial challenge standpoints as well as increased in-vivo investigation via clinical trials.

The management of treatment-resistant biliary calculi using percutaneous endourologic techniques.

BACKGROUND: Complicated choledocholithiasis cannot always be managed by standard surgical, radiologic or endoscopic methods. One additional approach is to use percutaneous techniques developed by endourologists to treat renal calculi. In this report, we present our experience over the past 10 years with this novel approach. METHODS: We conducted a retrospective review of all patients who underwent percutaneous, endoscopic treatment of biliary calculi at our institution between January 1997 and August 2007. Primary outcomes of interest were symptom- and stone-free rates, length of stay in hospital and complications. RESULTS: Nineteen patients underwent 21 percutaneous treatments for biliary calculi. All were dependent on external drainage for symptom control. The primary indications for treatment were cholangitis, retained stone, biliary colic and jaundice. Seventeen patients (89.5%) had failed prior endoscopic retrograde cholangiopancreatography (ERCP) or open attempts at treatment. The 2 remaining patients (10.5%) were deemed unfit for a general anesthetic. Patients had experienced a mean of 1.8 (standard deviation [SD] 1.0) prior failed attempts at stone removal. We used several treatment modalities, including holmium:yttrium-aluminum-garnet laser (61.9%), electrohydraulic lithotripter (19.0%), ultrasound (9.5%), basket extraction (9.5%) and balloon dilatation of the ampulla (19.0%). Overall, treatment led to successful removal of the biliary drainage tube in 94.7% of patients and 76.2% were stone-free. We performed cholangiograms an average of 21.8 (SD 13.7) days after treatment. The average length of stay in hospital was 1.9 (SD 1.1) days. One patient experienced a perioperative acute coronary syndrome and another experienced prolonged biliary drainage. Both had successful endoscopic treatment of their calculi. There were no cases of treatment-related sepsis, and we observed no other complications. CONCLUSION: Biliary calculi may be successfully treated using standard endourologic methods with high stone-free rates. This technique is generally well-tolerated even among high-risk patients.

The evolution of percutaneous nephrolithotomy: Analysis of a single institution experience over 25 years.

INTRODUCTION: Over time, the incidence of nephrolithiasis has risen significantly, and patient populations have become increasingly complex. Our study aimed to determine the impact of changes in patient demographics on percutaneous nephrolithotomy (PCNL) outcomes. METHODS: A retrospective analysis of a prospectively collected database was carried out from 1990-2015. Patient demographics, comorbidities, stone and procedure characteristics were analyzed. Multivariate logistic regression was used to evaluate differences in operative duration, complications, stone-free rate, and length of stay. RESULTS: A total of 2486 patients with a mean age of 54±15 years, body mass index (BMI) of 31±8, and stone surface area of 895±602 mm2 were analyzed; 47% of patients had comorbidities, including hypertension (22%), diabetes mellitus (14%), and cardiac disease (13%). Complication rate was 19%, including a 2% rate of major complications (Clavien grade III-V). There was a statistically significant increase in patient age, BMI, and comorbidities over time, which was correlated with an increased complication rate (odds ratio [OR] 1.15; p=0.010). The overall transfusion rate was 1.0% and remained stable (p=0.131). With time, both OR duration (mean Δ 16 minutes; p<0.001) and hospital length of stay (mean Δ 2.4 days; p<0.001) decreased significantly. Stone-free rate of 1873 patients with available three-month followup was 87% and decreased significantly over time (OR 1.09; p<0.001), but was correlated with an increased use of computed tomography (CT) scans for followup imaging. CONCLUSIONS: Despite an increasingly complex patient population, PCNL remains a safe and effective procedure with a high stone-free rate and low risk of complications.

Surgical simulation: a urological perspective.

PURPOSE: Surgical education is changing rapidly as several factors including budget constraints and medicolegal concerns limit opportunities for urological trainees. New methods of skills training such as low fidelity bench trainers and virtual reality simulators offer new avenues for surgical education. In addition, surgical simulation has the potential to allow practicing surgeons to develop new skills and maintain those they already possess. We provide a review of the background, current status and future directions of surgical simulators as they pertain to urology. MATERIALS AND METHODS: We performed a literature review and an overview of surgical simulation in urology. RESULTS: Surgical simulators are in various stages of development and validation. Several simulators have undergone extensive validation studies and are in use in surgical curricula. While virtual reality simulators offer the potential to more closely mimic reality and present entire operations, low fidelity simulators remain useful in skills training, particularly for novices and junior trainees. Surgical simulation remains in its infancy. However, the potential to shorten learning curves for difficult techniques and practice surgery without risk to patients continues to drive the development of increasingly more advanced and realistic models. CONCLUSIONS: Surgical simulation is an exciting area of surgical education. The future is bright as advancements in computing and graphical capabilities offer new innovations in simulator technology. Simulators must continue to undergo rigorous validation studies to ensure that time spent by trainees on bench trainers and virtual reality simulators will translate into improved surgical skills in the operating room.