Developing an Ex Vivo Pig Model for Teaching Ultrasound and Fluoroscopy-Guided Percutaneous Renal Access.

Introduction: Establishing percutaneous renal access is the key initial step to percutaneous nephrolithotomy; however, learning the technique during surgery for trainees is complicated by the number of approaches used to gain access, limited completion time during a breath hold. and attempt to minimize the number of passes through a kidney. There are many training models for percutaneous access commercially available all with their respective limitations. Our objective was to develop a low-cost, high-fidelity percutaneous access training model that addresses existing limitations and can be used with both ultrasound and fluoroscopy guidance. Methods: After a formal ethics exemption was attained, pig cadavers were harvested for flank, kidneys, and ureters. These were incorporated into a composite porcine tissue mould, created within a gelatin matrix. In the initial assessment, establishing percutaneous access under both ultrasound and fluoroscopy guidance was tested to refine usability. Once acceptable, its use during a training course was evaluated to assess impressions for use with ultrasound. Results: We were able to create a $45USD biodegradable model, which can facilitate percutaneous access using: fluoroscopy with intrarenal contrast; fluoroscopy with endoscopic guidance; and fluoro-less that is, ultrasound only. A cohort of 12 Canadian Postgraduate Year-3 residents who used the model for ultrasound access agreed that the model simulated a comparable tactile experience (58.33%) and anatomy (75%) to humans. Furthermore, majority of the residents agreed that model was easy to use with ultrasound guidance (91.67%), was a beneficial experience for their learning and future practice (83.33%) and if available would use to complement their intraoperative training (83.33%). Conclusion: We were able to develop a low-cost, preliminarily tested ex vivo pig model for percutaneous access compatible with multiple imaging modalities. We will continue refining our model and seek to understand its benefits when teaching percutaneous access to varying levels of learners.

Retrograde nephrostomy access for percutaneous nephrolithotomy: a simple and safe technique.

This study aimed at illustrating our experience with the retrograde nephrostomy access technique for percutaneous nephrolithotomy (PCNL).This retrospective study was conducted between June 1997 and September 2018 for 648 patients who underwent PCNL with retrograde nephrostomy access. Included in the study were the patient demographic, operative time, site of the access, fluoroscopic exposure time, stone clearance rate, additional procedures and complications. A total of 648 patients aged between 25 and 70 years had renal stones and were included in this study. Retrograde nephrostomy access was achieved through the upper calyx in 252 patients (38.9%), middle calyx in 348 patients (53.7%) and lower calyx in 48 patients (7.4%). Among those patients, 108 (16.7%) required supracostal access. The average time for the retrograde access and PCNL was 14.4 min and 40 min, respectively. The average fluoroscopic exposure time for the retrograde access was 3.2 min. There were 12 failures (1.9%) as a result of severe hydronephrosis. Complete stone clearance was achieved in 91.8%. Small stone fragments (4 mm or less) were detected in 7.4%. Median hospital stay was 3.5 days (range 3-7). Complications occurred in 39 patients (6%). Eight patients (1.2%) developed significant postoperative hemorrhage that was controlled by transfusion and angioembolization. There were no recorded cases of colonic injuries, pneumothorax or hemothorax, demonstrating that the retrograde access technique is safe and reliable. It provides control over both ends of the wire eliminating the risk of accidental wire displacement. Radiation exposure is minimal. There are low failure and complication rates.

Thiel-embalmed cadavers as a novel training model for ultrasound-guided supine endoscopic combined intrarenal surgery.

OBJECTIVE: To evaluate Thiel-embalmed cadavers (TEC) as a training model for percutaneous nephrolithotomy (PCNL), more specifically for ultrasound (US)-guided supine endoscopic combined intrarenal surgery (ECIRS). SUBJECTS AND METHODS: Thirteen urologists (nine experienced endourologists, four fellows/residents) performed an US-guided supine ECIRS procedure on a TEC. The model was evaluated by way of a questionnaire (5-point Likert scale). Descriptive statistical analysis was performed and results were graphically presented using divergent bar graphs. RESULTS: US images were appreciated as lifelike in all aspects. Although distention of the collecting system was not ideal in one out of three TEC, US visualisation of the distended calyces during puncture was good. Skin penetration was more difficult and less realistic in TEC, while kidney puncture and dilatation were deemed very realistic. Ureteric and collecting system anatomy and consistency were similar to real life, although the mucosa appeared paler. US needle guidance was perceived as excellent. Overall, needle puncture assessment was realistic and useful as a training tool. Overall quality and satisfaction of TEC in US-guided supine ECIRS was good to excellent and comparable to a real-life procedure. Overall appropriateness of the TEC model was considered excellent for both initial and advanced supine PCNL training. CONCLUSION: Despite the minor drawbacks of tough skin and non-ideal collecting system dilatation during ureteroscopy, the TEC model was considered good to excellent as a training model for US-guided PCNL, in particular, US-guided needle puncture of the kidney during supine ECIRS.

Pilot Assessment of Immersive Virtual Reality Renal Models as an Educational and Preoperative Planning Tool for Percutaneous Nephrolithotomy.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) requires the urologist to have detailed knowledge of the stone and its relationship with the renal anatomy. Immersive virtual reality (iVR) provides patient-specific three-dimensional models that might be beneficial in this regard. Our objective is to present the initial experience with iVR in surgeon planning and patient preoperative education for PCNL. MATERIALS AND METHODS: From 2017 to 2018 four surgeons, each of whom had varying expertise in PCNL, used iVR models to acquaint themselves with the renal anatomy before PCNL among 25 patients. iVR renderings were also viewed by patients using the same head-mounted Oculus rift display. Surgeons rated their understanding of the anatomy with CT alone and then after CT+iVR; patients also recorded their experience with iVR. To assess the impact on outcomes, the 25 iVR study patients were compared with 25 retrospective matched-paired non-iVR patients. Student's t-test was used to analyze collected data. RESULTS: iVR improved surgeons' understanding of the optimal calix of entry and the stone's location, size, and orientation (p < 0.01). iVR altered the surgical approach in 10 (40%) cases. Patients strongly agreed that iVR improved their understanding of their stone disease and reduced their preoperative anxiety. In the retrospective matched-paired analysis, the iVR group had a statistically significant decrease in fluoroscopy time and blood loss as well as a trend toward fewer nephrostomy tracts and a higher stone-free rate. CONCLUSIONS: iVR improved urologists' understanding of the renal anatomy and altered the operative approach in 40% of cases. In addition, iVR improved patient comprehension of their surgery. Clinically, iVR had benefits with regard to decreased fluoroscopy time and less blood loss along with a trend toward fewer access tracts and higher stone-free rates.

Contemporary practice patterns in the treatment of pediatric stone disease.

INTRODUCTION: To compare endourology versus pediatric urology exposure to pediatric stone cases during fellowship, comfortability in treating pediatric stone cases, and access to pediatric surgical equipment. MATERIALS AND METHODS: A survey was distributed to all pediatric urology fellowship programs and the Endourological Society. Age was stratified into < 12 months old, 12 months-4 years, 5-12 years, and 13-18 years. Exposure and comfortability performing extracorporeal shock wave lithotripsy (SWL), ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) were assessed across age groups. Exposure was assessed as 'yes/no' and comfortability was scaled from 1-5 ('would not do' to 'very comfortable'). RESULTS: Seventy-two surveys met inclusion criteria, with 23 (31.9%) from pediatric urologists and 49 (68.1%) by endourologists. During fellowship, pediatric urologists had more exposure to SWL in toddlers (p = 0.03) and school age children (p = 0.045), URS in toddlers (p = 0.012) and school age children (p = 0.002), and PCNL in infants (p = 0.031) and school age children (p = 0.025) compared to endourologists. Pediatric urologists were significantly more comfortable performing SWL in toddlers (p = 0.04), URS in toddlers (p = 0.04) and school age children (p = 0.04), and PCNL in school age children (p = 0.02) compared to endourologists. Endourologists were significantly more uncomfortable than pediatric urologists in performing URS in toddlers (p = 0.03) and PCNL in infants (p = 0.04) and school age children (p = 0.03). There were no differences in availability of pediatric equipment. CONCLUSIONS: Pediatric urologists, have significantly more exposure than endourologists during fellowship and are more comfortable performing surgical treatment for urolithiasis in most pediatric ages. Endourology fellowships may benefit from greater exposure to pediatric patients with stones.

Learning Curves in Urolithiasis Surgery: A Systematic Review.

BACKGROUND AND AIMS: Procedures for urolithiasis are a core part of the development for the urologist in training. Understanding the learning curve of the procedures is important, allowing for planning in the training and assessment of trainees. The aim of this study was to systematically review the literature pertaining to learning curves in urolithiasis surgery. MATERIALS AND METHODS: The review was registered on the PROSPERO database and conducted in keeping with the Preferred Reporting Items for Systematic reviews and Meta-Analysis statement. Embase, MEDLINE, and PsycINFO were systematically searched from inception to January 2018, with a reference review conducted. All empirical studies on learning curves in urolithiasis surgery were included irrespective of procedure. Articles describing pediatric surgery, nontechnical skills in surgery, or those not written in English were excluded. RESULTS: Of 390 articles identified from screening, a final 18 studies were included. Fourteen studies identified the learning curve in percutaneous nephrolithotomy. These studies identified a learning curve of between 30 and 60 cases for both operative time (OT) and complication rates. Four articles focused on flexible ureteroscopy (FURS); the learning curve for FURS has been outlined as 60 cases for OT and 56 cases for fragmentation efficacy. CONCLUSIONS: The complexities of determining learning curves are extensive; studies use different parameters to measure outcomes and observe skill acquisition rates of surgeons with differing prior experience. Evidence in this article can guide trainee urologists with regard to the expected rate of progress. Multi-operator multicenter research utilizing standard outcome measures should be conducted to establish definitive learning curves.

Differences in the percutaneous nephrolithotomy practice patterns among Latin American urologists with and without endourology training

ABSTRACT Purpose: Although the worldwide percutaneous nephrolithotomy (PCNL) practice pat- terns determined via a survey sent to members of the Endourological Society have been published, differences in PCNL practice patterns among Latin American urologists based on endourological or lithiasis training have not been published. To determine the PCNL practice patterns among Latin American urologists with and without training in endourology. Materials and Methods: The SurveyMonkey® web platform was used to develop a 27-item survey on PCNL for the treatment of renal stones, and the survey was sent via e- -mail and other electronic media to 2000 urologists from 15 Latin American countries. Endourology-trained (group 1) and nontrained urologists (group 2) were analyzed. The group results were compared using the chi-squared and Fisher's exact tests. SPSS version 20 for Windows was used for all analyses. Results: A total of 331 urologists responded to the survey (rate of 16.55%): 221 (66.7%) in group 1 and 110 (33.2%) in group 2). In groups 1 and 2, 91.9% and 63.2% performed PCNL, respectively: 85.1% and 58.5% used preoperative tomography, respectively; 12.7% and 4.7% used preoperative nephrolitometry nomograms, respectively: 45.2% and 32.1% used endoscopic combined intrarenal surgery, respectively: 68.3% and 38.7% used mul- tiple percutaneous tract realization, respectively: and 19.9% and 5.7% used minimally invasive PCNL, respectively (all p=0.0005). Conclusions: Statistically significant differences were observed in PCNL practice patterns of Latin American urologists with and without training in endourology. Specific training in endourology significantly influence the practice patterns of Latin American urologists.

Differences in the percutaneous nephrolithotomy practice patterns among Latin American urologists with and without endourology training.

PURPOSE: Although the worldwide percutaneous nephrolithotomy (PCNL) practice patterns determined via a survey sent to members of the Endourological Society have been published, differences in PCNL practice patterns among Latin American urologists based on endourological or lithiasis training have not been published. To determine the PCNL practice patterns among Latin American urologists with and without training in endourology. MATERIALS AND METHODS: The SurveyMonkey® web platform was used to develop a 27- item survey on PCNL for the treatment of renal stones, and the survey was sent via e-mail and other electronic media to 2000 urologists from 15 Latin American countries. Endourology-trained (group 1) and nontrained urologists (group 2) were analyzed. The group results were compared using the chi-squared and Fisher's exact tests. SPSS version 20 for Windows was used for all analyses. RESULTS: A total of 331 urologists responded to the survey (rate of 16.55%): 221 (66.7%) in group 1 and 110 (33.2%) in group 2). In groups 1 and 2, 91.9% and 63.2% performed PCNL, respectively; 85.1% and 58.5% used preoperative tomography, respectively; 12.7% and 4.7% used preoperative nephrolitometry nomograms, respectively; 45.2% and 32.1% used endoscopic combined intrarenal surgery, respectively; 68.3% and 38.7% used multiple percutaneous tract realization, respectively; and 19.9% and 5.7% used minimally invasive PCNL, respectively (all p=0.0005). CONCLUSIONS: Statistically significant differences were observed in PCNL practice patterns of Latin American urologists with and without training in endourology. Specific training in endourology significantly influence the practice patterns of Latin American urologists.

Implementation of minimally invasive percutaneous nephrolithotomy (MIP): comparison of the initial learning curve with the later on clinical routine in a tertiary centre.

OBJECTIVE: We report on the comparison of clinical results of the early phase of implementation of minimally invasive PNL (MIP) in a mentor-based approach with the later on clinical routine in a tertiary centre. PATIENTS AND METHODS: From January 2010 until January 2015 MIP was performed in 190 patients. Stone and patient characteristics were recorded in prospective manner. Perioperative complications were recorded within the Clavien-Classification. The first 120 consecutive patients undergoing MIP were evaluated and divided into three groups of 40 patients each. Mentor-based introduction of MIP was done within the first 40 patients (group A). Further patients were treated on routine clinical practice basis (group B and C). Treatment outcome was compared within the three groups. RESULTS: The groups did not significantly differ with regard to patient characteristics, operation time and decline in haemoglobin. In the mentor-based series mean stone size was 21.7 ± 12.6 vs. 15.6 ± 7.9 and 16.1 ± 8.4 mm in group B and C (p = 0.033). Primary stone-free rates were 65, 87.5 and 87.5% for the three groups (p = 0.015). Stone-free rate was higher in smaller and simple stones. Overall, complication rate was 41.7% including 36.7% Clavien grade I and II complications. CONCLUSIONS: MIP can be implemented safe and effectively with mentor-based approach. MIP has a high safety profile, which allows high safety and efficacy of MIP at the time of implementation.

Outcome from 5-year live surgical demonstrations in urinary stone treatment: are outcomes compromised?

PURPOSE: To compare intra- and post-operative outcomes of endourological live surgical demonstrations (LSDs) and routine surgical practice (RSP) for urinary stones. METHODS: Consecutive ureterorenoscopic (URS) and percutaneous (PNL) urinary stone procedures over a 5-year period were reviewed. Procedures were divided into LSDs and RSP. Differences between the groups were separately analysed for URS and PNL. Primary outcomes included intra- and post-operative complication rates and grades. Secondary outcomes were operation time, length of hospital stay, stone-free rate, and retreatment rate. Pearson's Chi-square analysis, Mann-Whitney U test, and logistic and linear regression were used to compare outcomes between LSDs and RSP. RESULTS: During the study period, we performed 666 URSs and 182 PNLs, and 151 of these procedures were LSDs. Among URSs, the overall intra-operative complication rate was 3.2% for LSDs and 2.5% for RSP (p = 0.72) and the overall post-operative complication rate was 13.7% for LSDs and 8.8% for RSP (p = 0.13). Among PNLs, the overall intra-operative complication rate was 8.9% for LSDs and 5.6% for RSP (p = 0.52) and the overall post-operative complication rate was 28.6% for LSDs and 34.9% for RSP (p = 0.40). For both URSs and PNLs, no statistically significant differences in complication grade scores were observed between LSDs and RSP. Operation time was significantly longer for LSD-URS group, but there was no difference between the PNL groups. There were no significant differences in length of hospital stay and stone-free rate. The retreatment rate was higher in the LSD-URS group compared with RSP-URS group but similar between the PNL groups. Multiple logistic regression analyses, adjusting for confounders, revealed no association between LSD and more or less favourable outcomes as compared to RSP. CONCLUSION: Live surgical demonstrations do not seem to compromise patients' safety and outcomes when performed by specialised endourologists.