Simulation for Percutaneous Renal Access: Where Are We?

Ex Vivo Porcine Model for Ureteral Stent Placement Training

Realistic simulation models for interventional radiology procedures are limited, including for placement of double-J ureteral stents (DJSs). Using a porcine kidney and empty saline bag (bladder), an ex vivo model aiming to improve operators' knowledge and confidence in performing a DJS procedure was developed. Six faculty (J.W., J.L.) and 14 trainees (C.B.O.) successfully operated on the model. Mean results for faculty versus trainees were as follows: 2.2 (SD ± 1.5) versus 2.4 (SD ± 1.5) puncture attempts to access the collecting system (P = .78), 14.5 minutes (SD ± 4.8) versus 15.1 minutes (SD ± 6.0) for insertion time (P = .84), 7.3 minutes (SD ± 2.8) versus 10.3 minutes (SD ± 2.6) for exchange time (P = .04), 8.48 minutes (SD ± 2.0) versus 8.01 minutes (SD ± 2.6) for fluoroscopy time (P = .70), and 5.7 mGy (SD ± 1.6) versus 5.4 mGy (SD ± 2.0) for absorbed air kerma (P = .77). Self-assessed knowledge and confidence with DJS placement increased for all participants following model use.

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.

Percutaneous nephrolithotomy - the puncture

OBJECTIVE

To determine what importance is given to the puncture and assistive technologies in percutaneous nephrolithotomy (PNL) in the current urological literature.

METHODS

PubMed was searched for English publications and reviews for the keywords: 'percutaneous nephrolithotomy', 'percutaneous nephrostomy', 'puncture'. The search was limited to the last 5 years, January 2016 until February 2021. Based on 183 abstracts, 121 publications were selected, read, and reviewed. References, older or seminal papers were read and cited if they contributed to a better understanding. A total of 198 references form the basis of this narrative review.

RESULTS

The puncture is frequently referred to as the most crucial part of PNL. In contrast, the influence of the puncture on the failure rate of PNL and the specific puncture-related complications seems to be low in the single-digit percentage range. However, there are no universally accepted definitions and standards measuring the quality of puncture. Consequently, the impact of the puncture on general PNL complications, on stone scores predicting success rates and on learning curves evaluating surgeons' performance have not been systematically studied. Assistive technologies rely on fluoroscopy and ultrasonography, the latter of which is becoming the preferred imaging modality for monitoring the entire procedure. Needle bending, a problem relevant to all puncture techniques, is not addressed in the urological literature.

CONCLUSIONS

The importance attached to puncture in PNL in the current urological literature is subjectively high but objectively low. Some basics of puncture are not well understood in urology. Disciplines other than urology are more actively involved in the development of puncture techniques.

Simulation-Based Percutaneous Renal Access Training: Evaluating a Novel 3D Immersive Virtual Reality Platform

Introduction: Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for patients with a large stone burden. There are a variety of methods to teach this important endourologic procedure, including simulation. We evaluated three different PCNL simulation platforms for potential use in teaching and assessing percutaneous renal access skills. Materials and Methods: Urology residents, fellows, and faculty were recruited to participate in this study, which included completing standardized tasks on three PCNL simulation platforms: a virtual reality (VR) simulator (PercMentor, 3D Systems™), a porcine tissue simulator (Cook™ Medical), and a new 3D immersive VR simulator-Marion K181 (Marion Surgical™). Participants were asked to complete a standardized task-gaining prone percutaneous renal access using a fluoroscopic-guided technique. Participants were asked to rate the simulators, and performance data were recorded for analysis. Results: A total of 18 participants with varying levels of PCNL experience completed the study. The Marion K181 had higher ratings by participants in all domains (realism, tactile feedback, instrument movement, renal anatomy, fidelity of simulation, utility as teaching tool) compared with the PercMentor (p < 0.05) but did not differ in any domain when compared with the porcine PCNL model. Participants felt that the Marion K181 was comparable with the porcine PCNL model as a teaching tool, but had the advantage of not requiring radiation exposure. Fluoroscopy time was the variable that most consistently correlated with participant PCNL experience and level of training, across all three PCNL simulation platforms. Conclusions: There are a variety of PCNL simulation platforms available for teaching percutaneous renal access skills. Based on our initial comparative study, there is validity evidence to support the use of the novel Marion K181 PCNL simulator as a training tool rather than higher fidelity models requiring real radiation exposure. However, evidence is yet lacking for its use as an assessment tool.

Image-guided study of swine anatomy as a tool for urologic surgery research and training

PURPOSE

To describe the anatomy of the swine urinary system using computed tomography and to discuss the role of this animal as an experimental model for urological procedures.

METHODS

Three male Landrace pigs underwent computed tomography and the anatomy of the urinary system and renal circulation was analyzed and described.

RESULTS

In all animals, 2 kidneys, 2 ureters and one bladder were identified. Each kidney presented a single renal artery vascularization, with a mean diameter on the right of 4.45 and 5.31 mm on the left (p < 0.0001) and single renal vein drainage, with a mean diameter on the right of 5.78 and 5.82 mm on the left (p = 0.0336). The average renal length was 9.85 cm on the right and 10.30 cm on the left (p < 0.0001). The average renal volume was 113.70 cm3 on the right and 109.70 cm3 on the left (p < 0.0001). The average length of the ureter was 19.78 cm on the right and 22.08 cm on the left (p < 0.0001). The average bladder volume was 423.70 cm3.

CONCLUSIONS

The data obtained show similarities with human anatomy, suggesting the viability of the swine model for planning preclinical trials, basic research, refinement in experimental surgery and surgical training for urological procedures.

Three-dimensionally printed non-biological simulator for percutaneous nephrolithotomy training

Objective: We sought to improve the educational and pre-operative training on various stages of percutaneous nephrolithotomy (PCNL) under fluoroscopic and ultrasound guidance. We developed a three-dimensional (3D) printed simulator (3D-printed PCNL model) for urological trainees.Methods: 40 s year urology residents were randomly assigned into two groups, completing PCNL surgical steps on a URO Mentor™ surgical simulator (Group A) or on our new 3D-printed PCNL model (Group B). Following the training, both groups completed a standardized questionnaire (Likert scale from 0 to 10) which we used to asses the learning curve associated with PCNL training.Results: The mean score of Group A was 65.2/80 while Group B was 76.1/80. Mann-Whitney U-test showed no significant difference between the groups (U = 16, p < 0.05).Conclusion: The 3D-printed PCNL model developed is a novel and highly effective tool that can facilitate enhanced endourological education and personalized pre-operative planning for urolithiasis cases. According to the criteria tested, residents who used our 3D-printed PCNL models performed better under all metrics.

Current Status of Simulation Training in Urology: A Non-Systematic Review

Simulation has emerged as an effective solution to increasing modern constraints in surgical training. It is recognized that a larger proportion of surgical complications occur during the surgeon's initial learning curve. The simulation takes the learning curve out of the operating theatre and facilitates training in a safe and pressure-free environment whilst focusing on patient safety. The cost of simulation is not insignificant and requires commitment in funding, human resources and logistics. It is therefore important for trainers to have evidence when selecting various simulators or devices. Our non-systematic review aims to provide a comprehensive up-to-date picture on urology simulators and the evidence for their validity. It also discusses emerging technologies and future directions. Urologists should embed evidence-based simulation in training programs to shorten learning curves while maintaining patient safety and work should be directed toward a validated and agreed curriculum.

Review of the effect of 3D medical printing and virtual reality on urology training with ‘MedTRain3DModsim’ Erasmus + European Union Project

Background/aim

It is necessary to incorporate novel training modalities in medical education, especially in surgical fields, because of the limitations of cadaveric training. Traditional medical education has many drawbacks, such as residency working hour restrictions, patient safety conflicts with the learning needs, and the lack of hands-on workshops. The MedTRain3DModsim Project aimed to produce 3-dimensional (3D) medical printed models, simulations, and innovative applications for every level of medical training using novel worldwide technologies. It was aimed herein to improve the interdisciplinary and transnational approaches, and accumulate existing experience for medical education, postgraduate studies, and specialty training.

Materials and methods

This project focused on models of solid organs and the urinary system, including the kidney, prostate, ureter, and liver. With 3D medical printing, it is possible to produce a body part from inert materials in just a few hours with the standardization of medical 3D modeling.

Results

The target groups of this project included medical students and residents, graduate students from engineering departments who needed medical education and surgical training, and medical researchers interested in health technology or clinical and surgical an atomy.

Conclusion

It was also intended to develop a novel imaging platform for education and training by reevaluating the existing data using new software and 3D modalities. Therefore, it was believed that our methodology could be implemented in all related medical fields.

Real-Time Needle Force Modeling for VR-Based Renal Biopsy Training with Respiratory Motion Using Direct Clinical Data

Realistic tool-tissue interactive modeling has been recognized as an essential requirement in the training of virtual surgery. A virtual basic surgical training framework integrated with real-time force rendering has been recognized as one of the most immersive implementations in medical education. Yet, compared to the original intraoperative data, there has always been an argument that these data are represented by lower fidelity in virtual surgical training. In this paper, a dynamic biomechanics experimental framework is designed to achieve a highly immersive haptic sensation during the biopsy therapy with human respiratory motion; it is the first time to introduce the idea of periodic extension idea into the dynamic percutaneous force modeling. Clinical evaluation is conducted and performed in the Yunnan First People's Hospital, which not only demonstrated a higher fitting degree (AVG: 99.36%) with the intraoperation data than previous algorithms (AVG: 87.83%, 72.07%, and 66.70%) but also shows a universal fitting range with multilayer tissue. 27 urologists comprising 18 novices and 9 professors were invited to the VR-based training evaluation based on the proposed haptic rendering solution. Subjective and objective results demonstrated higher performance than the existing benchmark training simulator. Combining these in a systematic approach, tuned with specific fidelity requirements, haptically enabled medical simulation systems would be able to provide a more immersive and effective training environment.

Development of a photographic handbook to improve cystoscopy findings during resident's training: A randomised prospective study

Objectives: To evaluate if the use of a photographic handbook (PH) can be a useful tool to improve the detection of disorders during cystoscopy training, as several hands-on tools have been proposed to improve technical skills but very few aim to improve specificity and sensitivity.

Subjects and methods: Eight junior residents (JRs) were divided into two groups: Group A, comprised four JRs with previous limited experience of performing cystoscopies; and Group B, including four inexperienced JRs who were asked to study a specific PH before performing cystoscopies. The findings of the two groups were compared using the chi-squared test.

Results: A total of 401 consecutive cystoscopies, of which 214 (53.4%) were performed by Group A and 187 (46.6%) by Group B, were considered. Group B showed superior ability in detecting uncommon findings (i.e., carcinoma in situ, bullous oedema, interstitial cystitis, etc.) with 24/46 (52.2%) detected vs eight of 32 (25%) in Group A (P = 0.016).

Conclusions: The PH was a useful tool for improving identification of pathological conditions, which could be used to enhance hands-on simulator and practical tutored training.

Abbreviations: CIS: carcinoma in situ; JR: junior resident; PH: photographic handbook; VR: virtual reality Classification: Stones/Endourology

Lessons Learned and New Challenges: Re-evaluation of End-User Assessment of a Skills-Based Training Program for Urology Trainees

OBJECTIVES

To re-assess the perceived benefit and relevance of simulation sessions to Victorian urology trainees and to identify areas for potential improvement.

SUBJECTS AND METHODS

All trainees attending skills training sessions between 2011 and 2016 were asked to complete a structured questionnaire at the completion of the session. The questionnaire included 11 topic areas ranging from the year of surgical training to degree of usefulness of the session, including several sections for free-text response to offer more detailed feedback. Sessions were examined both individually and collectively to assess end-user satisfaction with the structure and content of the program.

RESULTS

In total, 24 individual skills sessions were held over the 6-year period, with a total of 355 attendees. Of these, 331 attendees completed the majority of the questionnaire, a response rate of over 93%. Overall 88% of the surveyed attendees stated that they had both the support of their supervising consultant and the flexibility of workload to attend the session; 90% of trainees felt that there was adequate reading material provided prior to the skills session, an improvement from 76% in the previous study period; and 97% of those surveyed felt that the existing session structure was appropriate and the same proportion found the sessions both useful and interesting, compared with just 63% in the previous study period. Analysis of individual topics demonstrates some variability in outcome measures, but for nearly every assessed parameter, greater than 90% of participants agreed that the session fulfilled the expected criteria. New topics developed since the 2011 analysis, including renal transplant and vascular repair, also had high levels of satisfaction. The practical models used have been refined and achieved higher scores than those in the previous assessment period.

CONCLUSION

The urology skills-based training program has been well received by the surveyed trainees and is now embedded and accepted as part of the Victorian training program. The format of the sessions has matured and the overall rating, both individually and collectively, was high. There has been a clear increase in satisfaction across most areas assessed when compared with previous feedback. Despite this, there remain areas that can be improved, such as the amount and quality of available equipment and the inclusion of video demonstrations of operative techniques.

Introduction of an ex-vivo pig model for teaching percutaneous nephrolithotomy access techniques

INTRODUCTION

In North America, obtaining access for percutaneous nephrolithotomy (PCNL) is not often performed by urologists. Hands-on training sessions help to ensure this skill continues within the urological community. An ex-vivo pig kidney model was developed for simulation. This model uses porcine tissues with a fluoroscopic C-arm and standard PCNL equipment. The bullseye or triangulation techniques are both possible. We propose this as a high-fidelity tool for teaching PCNL access.

METHODS

The pig kidney, fat, ribs, flank, and skin were arranged anatomically on a table with fluoroscopy. Hands-on training was provided to residents and urologists using the ex-vivo pig model and a silicone-based percutaneous access model. Questionnaires were given at the end of the session.

RESULTS

There was a total 14 responders for each model, with incomplete responses on two surveys. A total of 15% of responders for the pig model and 7% of responders for the silicone model had previous percutaneous access experience. For the pig model, 93% of trainees agreed or strongly agreed that the model was easy to use, and 79% of the silicone model trainees felt the same. After the session, 50% of silicone model trainees and 86% of pig model trainees reported increased confidence in their ability to obtain PCNL access. All the pig model trainees and 71% of the silicone model trainees felt that the simulation activity was worthwhile.

CONCLUSIONS

The inexpensive but anatomically realistic ex-vivo pig model using real-world equipment provides trainees with an excellent tool to learn PCNL access.

Incorporation of the fluoroless C-Arm Trainer at the American Urological Association hands on training percutaneous renal access

OBJECTIVES

To assess for usefulness and validity evidence for incorporating the C-Arm Trainer (CAT) simulator into the annual AUA hands on course for training percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

The course started with a didactic session followed by four stations for training the "bull's eye" technique using the CAT simulator. Each station included a pre-test, 30-min practice on the simulator, and post-test. All participants were assessed using a 4-item checklist. All participants were asked to fill in a qualitative self-assessment questionnaire after the pre- and the post-test, and respond to a course evaluation questionnaire and post-course survey.

RESULTS

A total of 38 physicians, who attended the hands on course, voluntarily participated in the study. Only 21.1% had previous practice on PCNL simulators. Compared with the results of the checklist total score and the qualitative self-assessment questionnaire scores after the pre-test, there was significant improvement in the checklist total score (p < 0.001), temporal demands (p = 0.003), situational stress (p = 0.003, and performance (0.003) after the post-test. A total of 14 (36%) participants responded to the course evaluation questionnaire, 50% evaluated the course as excellent, 28.6% as very good, and 21.4% as good. Unfortunately, only five (13%) participants responded to the post-course survey, 4/5 implemented the new competencies and knowledge into their practice, and 3/5 have attempted to obtain fluoroscopic guided PCA without assistance.

CONCLUSION

The CAT simulator was considered useful for training the percutaneous renal access procedure. There was significant improvement in the qualitative and quantitative assessment parameters after the post-test compared with the pre-test.

[Ablative therapy in urology: Good practice and perspective]

INTRODUCTION

To expose the main point of discussion from present ablative therapies' guidelines and propose global perspectives.

MATERIALS AND METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com/) using different associations of keywords "ablative therapy" ; "prostate cancer"; "kidney cancer"; "guidelines"; "hybrid operating room". Publications obtained were selected based on methodology, language and relevance.

RESULTS

Present guidelines on ablative therapies in urology are, considering authors and organs, either particularly prudent (EAU guidelines for prostate and kidney) or relatively optimistic (CIRSE guidelines). This discrepancy is related to a low level of proof. So, a new approach is mandatory: more homogeneous in methodology, and especially more open to a new organization sparing economic efficiency. The objective will be to get multifunctional and multidisciplinaries platforms, in facts and in minds. It will induce, in the future, a deep reflection about training and boundaries' specialties.

CONCLUSION

Ablative therapies represent a crucial stake for urology and a clear example of medicosurgical evolution in future, based on new technologies (energy, robotic, imaging). A serious and deep reflection is necessary to prepare it and be deeply involved in.