Training in ureteroscopy: a critical appraisal of the literature

Feasibility of respiratory synchronization for laser lithotripsy using a robotic retrograde intrarenal surgery system Zamenix™ in an in-vitro model

OBJECTIVES

This study aims to investigate the improvement of stone fragmentation efficiency and safety in robotic-assisted retrograde intrarenal surgery (RIRS) that implements the respiratory motion synchronization using an in vitro model.

MATERIALS AND METHODS

Laser lithotripsy was performed in three groups: manual procedure (group M), robotic procedures without respiratory synchronization (group RNR), and robotic procedures with respiratory synchronization (group RR). The study assessed fragmentation time, laser time, number of mucosal contacts, and total energy used. Two surgeons having different experience of conventional RIRS (> 2500 and < 500) were participated.

RESULTS

In overall results of the two surgeons, the fragmentation time significantly decreased to 74.8% in group RNR (P = 0.012) and 65.0% in group RR (P = 0.001), compared to group M. The laser time was significantly shorter in group RR compared to the group M (P = 0.003). The number of mucosal contacts was significantly reduced to 37.4% in group RNR (P = 0.048) and it was 34.0% in group RR, compared to group M. The total energy significantly decreased in group RR compared to group M (P = 0.011). There were no significant differences between group RR and RNR across all outcomes in the overall results of the two surgeons. For less experienced surgeon, the fragmentation time was significantly shorter in group RR compared to group RNR (P = 0.013).

CONCLUSIONS

Robotic-assisted RIRS resulted in reduced fragmentation time, laser time, mucosal contacts, and total energy compared to manual RIRS during laser lithotripsy. The incorporation of respiratory synchronization in robotic-assisted RIRS reduced laser time compared to manual RIRS and shortened the fragmentation time compared to the robotic-assisted RIRS without respiratory synchronization, particularly for less experienced surgeon. These initial results demonstrated the feasibility of robotic-assisted RIRS with respiratory synchronization, highlighting its potential to improve procedural efficiency and safety.

Does tidal volume during mechanical ventilation affect pediatric retrograde intrarenal surgery outcomes?

PURPOSE

The aim of the study was to analyze the effect of tidal volume during mechanical ventilation (MV) on pediatric retrograde intrarenal surgery (RIRS) outcomes.

METHODS

The data of patients who underwent RIRS between January 2018 and January 2023 were retrospectively analyzed. Patients under the age of 18 who underwent RIRS and whose data were available were included in the study. Patients were divided into two groups, ≤ 7 ml/kg (Group 1) and > 7 ml/kg (Group 2), according to the tidal volume during MV. Demographic data, clinical characteristics, and perioperative and postoperative data of the patients were statistically compared in both groups.

RESULTS

A total of 83 patients were enrolled, with a mean age of 6.9 ± 4.5 (1-17) years and a mean stone size of 11.7 ± 5.4 (5-33) mm. There were 31 patients in Group 1 and 52 patients in Group 2. The demographic data and clinical characteristics of the patients in both groups were comparable. There was no statistically significant difference between the two groups regarding stone-related (side, size, density, number, and location) and surgical (access sheath and basket use, operation time, fluoroscopy time, or postoperative stenting rates, complication rates) parameters. In the first month, the stone-free rate was higher in Group 1 than in Group 2 (90.3% vs. 71.1%, p = 0.03). No high-grade or anesthesia-related complications were observed in any of the patients.

CONCLUSION

Reducing tidal volume in pediatric RIRS may improve the stone-free rate by facilitating laser targeting and increasing operative field stability and surgical comfort.

Cumulative morbidity of ureteroscopy for upper tract urothelial carcinoma

OBJECTIVE

To assess complications after ureteroscopy (URS) for upper tract urothelial carcinoma (UTUC) management and to assess its postoperative cumulative morbidity burden using the Comprehensive Complication Index (CCI).

MATERIALS AND METHODS

Single center retrospective study including patients submitted to URS for UTUC suspicion. URSs were both diagnostic and operative. Postoperative complications were recorded according to the EAU Guidelines and graded according to Clavien-Dindo Classification (CDC). The cumulative postoperative morbidity burden developed by patients experiencing multiple events was assessed using the CCI. Multivariable logistic regression (MLR) analyses identified factors independently associated with the development of any grade and major postoperative complications.

RESULTS

Overall, 360 patients with UTUC suspicion were included with a total of 575 URSs performed. The cumulative number of all postoperative complications recorded was 111. In 86 (15%) procedures, patients experienced at least one postoperative complication, while 25 (4.3%) experienced more than one complication. Of these, 16 (14%) were severe (CDC ≥ IIIa). The most frequent type of complications were urinary (34%), bleeding (30%) and infectious (30%). The higher the CDC grade, the higher the median CCI, with a statistically significant increase in median CCI from CDC II to major complications. Patients who experienced intraoperative complications were at higher risk of developing any grade and major postoperative complications at MLR.

CONCLUSIONS

Complications after ureteroscopy for UTUC are relatively uncommon events. Patients who experience intraoperative complications are at higher risk of developing postoperative complications. The comprehensive complication index appeared more representative of the cumulative postoperative morbidity rather than the Clavien-Dindo classification.

Design and Validation of a Novel 3D-Printed Retrograde Intrarenal Surgery Trainer

OBJECTIVE

To report on the design of a novel 3D-printed retrograde intrarenal surgery (RIRS) benchtop trainer and detail its validation against real-life experiences.

METHODS

Digital Imaging and Communications in Medicine (DICOM) files of 2 patients with normal computed tomography of the kidney and bladder were converted into stereolithography files to create 3D triangular mesh models. These images were further refined using Autodesk Meshmixer. These 3D models were fabricated through additive manufacturing, a process commonly known as 3D printing, and assembled in a polypropylene case. After development, the model was validated by 40 experienced urologists and urology residents in their final year of training. They were asked to rate the components of the simulation using a 9-point questionnaire.

RESULTS

The model's value in understanding the principles of RIRS and simulating contextual anatomy had mean scores of 9.43 (standard deviation [SD] = 0.74) and 9.21 (SD = 1.03), respectively. Mean scores for specific steps in RIRS were 8.07 (SD 1.47) for cannulating the ureteric orifice, 8.61 (SD 1.24) for inserting the ureteric access sheath, 9.29 (SD 0.97) for performing a renoscopy and evaluating all the calyces, 9.46 (SD 0.87) for laser lithotripsy, and 9.17 (SD 0.94) for manual stone retrieval. Participants scored the model with a mean score of 9.04 (SD 0.87) regarding realism and a mean score of 9.18 (SD 0.89) when evaluating its ability to enhance a trainee's confidence in RIRS.

CONCLUSION

The model performed well for all components of RIRS. This model allows high fidelity of the simulation and is cost-effective, portable, durable, reusable, and compatible with standard ureteroscopes.

An international delphi survey and consensus meeting to define the risk factors for ureteral stricture after endoscopic treatment for urolithiasis

PURPOSE

Iatrogenic ureteral strictures (US) after endoscopic treatment for urolithiasis represent a significant healthcare concern. However, high-quality evidence on the risk factors associated with US is currently lacking. We aimed to develop a consensus statement addressing the definition, risk factors, and follow-up management of iatrogenic US after endoscopic treatment for urolithiasis.

METHODS

Utilizing a modified Delphi method, a steering committee developed survey statements based on a systematic literature review. Then, a two-round online survey was submitted to 25 experts, offering voting options to assess agreement levels. A consensus panel meeting was held for unresolved statements. The predetermined consensus threshold was set at 70%.

RESULTS

The steering committee formulated 73 statements. In the initial survey, consensus was reached on 56 (77%) statements. Following in-depth discussions and refinement of 17 (23%) statements in a consensus meeting, the second survey achieved consensus on 63 (86%) statements. This process underscored agreement on pivotal factors influencing US in endoscopic urolithiasis treatments.

CONCLUSIONS

This study provides a comprehensive list of categorized risk factors for US following endoscopic urolithiasis treatments. The objectives include enhancing uniformity in research, minimizing redundancy in outcome assessments, and effectively addressing risk factors associated with US. These findings are crucial for designing future clinical trials and guiding endoscopic surgeons in mitigating the risk of US.

Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis

PURPOSE

We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors.

METHODS

We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design).

RESULTS

A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively.

CONCLUSIONS

The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

Role of simulation in kidney stone disease: A systematic review of literature trends in the 26 years

BACKGROUND

Minimally invasive techniques for treatment of urinary stones requires expertise, experience and endoscopic skills. Simulators provide a low-stress and low-risk environment while providing a realistic set-up and training opportunities.

AIM

To report the publication trend of 'simulation in urolithiasis' over the last 26 years.

METHODS

Research of all published papers on "Simulation in Urolithiasis" was performed through PubMed database over the last 26 years, from January 1997 to December 2022. Papers were labelled and divided in three subgroups: (1) Training papers; (2) Clinical simulation application or surgical procedures; and (3) Diagnostic radiology simulation. Each subgroup was then divided into two 13-year time periods to compare and identify the contrast of different decades: period-1 (1997-2009) and period-2 (2010-2022).

RESULTS

A total of 168 articles published on the application of simulation in urolithiasis over the last 26 years (training: n = 94, surgical procedures: n = 66, and radiology: n = 8). The overall number of papers published in simulation in urolithiasis was 35 in Period-1 and 129 in Period-2, an increase of +269% (P = 0.0002). Each subgroup shows a growing trend of publications from Period-1 to Period-2: training papers +279% (P = 0.001), surgical simulations +264% (P = 0.0180) and radiological simulations +200% (P = 0.2105).

CONCLUSION

In the last decades there has been a step up of papers regarding training protocols with the aid of various simulation devices, with simulators now a part of training programs. With the development of 3D-printed and high-fidelity models, simulation for surgical procedure planning and patients counseling is also a growing field and this trend will continue to rise in the next few years.

Retrograde Intrarenal Surgery Learning Curves of Urology Residents Supervised by an Experienced Endourologist: An RIRSearch Study

INTRODUCTION

Although retrograde intrarenal surgery (RIRS) is being performed with increasing frequency, there are only a limited number of studies about the learning curve (LC). This study aimed to analyze the LC of RIRS for five surgeons who underwent the same training.

MATERIALS AND METHODS

The data of the 410 patients who underwent RIRS between April 2017 and 2022 in a single institution, which were performed consecutively by five surgeons, were analyzed. All 50 cases performed by each surgeon were included and numbered consecutively and separately, according to the date of the operation. The combined stone-free rate (SFR) was calculated for each surgeon's cases in the same row, and the LCs were created using moving average and cumulative sum (CUSUM) analyses. Separate multivariable analyses identified each period's (LC vs. beyond) characteristics.

RESULTS

The LCs from the combined SFRs reached a plateau after approximately 50 cases for both the CUSUM and the moving average. The effect of stone burden on SFR was more evident in the first 50 cases compared to subsequent cases in the multivariable analyses (p = 0.001 and p = 0.047, respectively). Case order and stone density were independent factors in the first 50 cases (OR: 1.02 [95% CI 1.00-1.04], p = 0.04 and OR: 0.99 [95% CI 0.99-1.00], p = 0.04) but not significant in subsequent cases (OR: 0.97 [95% CI 0.94-1.00], p = 0.1 and OR: 1.00 [95% CI 0.99-1.00], p = 0.7, respectively). Compared to single locations except the lower calyx, the unfavorable effect of the multiple-stone localization on SFR grew in strength after the 50th case (OR: 0.42 [95% CI 0.23-0.78], p = 0.01 and OR: 0.20 [95% CI 0.09-0.46], p < 0.001, respectively).

CONCLUSIONS

This is the first study reporting on the RIRS LCs of urology residents. While stone burden, density, and multiple-stone localization were the factors determining SFR in the learning period, after completing the LC, the effect of stone burden weakened and multiple-stone localization became stronger.

Learning curve in flexible ureteroscopy for renal stones: A propensity score-matched study

OBJECTIVE

To assess the learning curve and evaluate the impact of surgical experience related to the outcomes of flexible ureteroscopy (fURS) for upper urinary tract stones.

METHOD

We evaluated retrospectively lithiasis fURS performed in our institution between January 2004 and December 2020. Patients were divided into two groups by the number of procedures performed by surgeon. Group 1 (G1) included the first 50 procedures, and group 2 (G2) the next cases. These groups were matched on baseline characteristics by a propensity score. Stones free rate (SFR) and complication rate (CR) were compared. Learning curves were realized using logistic curve with 95% confidence interval.

RESULTS

After criteria exclusion and propensity score matching, 1548 procedures were analyzed (1:1, G1 and G2, n=774 procedures). A total of 29 surgeons were evaluated. The overall SFR was 68.4% without statistical difference between the two groups (G1=67.9% vs. G2=68.8%, P=0.72). The surgeon's experience was not associated with SFR (OR=1.15, 95% CI: 0.90-1.47), except in subgroup stones>2cm (OR=2.89, 95% CI: 1.29-6.46). The overall CR was 12.5%, mainly Clavien-Dindo grade I-II complications (96.2%). Surgical experience was not associated with CR (OR=1.06, 95% CI: 0.77-1.45). The overall logistic curves for probability of stone clearance and complication tended to be a flat slope.

CONCLUSION

Impact of surgical experience on fURS for UUTS was not associated with SFR and CR. However, for stones larger than 2cm, surgeon's experience tended to be associated with SFR, but without impact on overall complications.

LEVEL OF EVIDENCE: 3

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion

OBJECTIVE

To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years.

METHODS

We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics.

RESULTS

During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43).

CONCLUSIONS

We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

A High-Fidelity Artificial Urological System for the Quantitative Assessment of Endoscopic Skills

Minimally-invasive surgery is rapidly growing and has become a standard approach for many operations. However, it requires intensive practice to achieve competency. The current training often relies on animal organ models or physical organ phantoms, which do not offer realistic surgical scenes or useful real-time feedback for surgeons to improve their skills. Furthermore, the objective quantitative assessment of endoscopic skills is also lacking. Here, we report a high-fidelity artificial urological system that allows realistic simulation of endourological procedures and offers a quantitative assessment of the surgical performance. The physical organ model was fabricated by 3D printing and two-step polymer molding with the use of human CT data. The system resembles the human upper urinary tract with a high-resolution anatomical shape and vascular patterns. During surgical simulation, endoscopic videos are acquired and analyzed to quantitatively evaluate performance skills by a customized computer algorithm. Experimental results show significant differences in the performance between professional surgeons and trainees. The surgical simulator offers a unique chance to train endourological procedures in a realistic and safe environment, and it may also lead to a quantitative standard to evaluate endoscopic skills.

Learning curve of semi-rigid ureteroscopy for small calculi: how many cases are necessary?

INTRODUCTION

semi-rigid ureteroscopy is the procedure of choice for the treatment of ureterolithiasis, but it requires a learning curve to be performed safely.

OBJECTIVE

To describe an estimate of the learning curve for performing semi-rigid ureterorenolithotripsy in patients with small-sized ureterolithiasis and to estimate the minimum number of procedures necessary to safely perform the surgical procedure.

METHODS

this is a prospective study evaluating the learning curve of a resident of urology in the first 60 semirigid ureteroscopies in patients with ureterolithiasis up to 1cm. The patients were divided into three groups: Group I one to twenty surgeries, Group II twenty one to forty surgeries and Group III forty one to sixty surgeries. The surgeries were recorded and analyzed by two urologists experienced in endourology. A qualitative analysis was performed based on a previously validated tool and a quantitative analysis.

RESULTS

all qualitative variables had significant variation between Groups I and II (p<0.001), and between Groups I and III (p<0.001). There was a difference in time to access the ureter, passage of a double J catheter and total operative time between Groups I and II (p<0.001) and Groups I and III (p<0.001).

CONCLUSION

after 40 cases there seems to be little increase in both quantitative as well as qualitative evaluation in surgical performance for performing semi-rigid ureterolithotripsy safely in calculations up to 1cm.

The learning curve for retrograde intrarenal surgery: A prospective analysis

INTRODUCTION

retrograde intrarenal surgery (CRIR) is an evolving tool. Its learning curve is not well established, despite the common use of flexible ureteroscopes today. Our aim is to estimate the number of procedures needed for one to perform RIRS consistently.

MATERIAL AND METHODS

a urology resident had his first 80 RIRS for nephrolithiasis analyzed quantitatively and qualitatively. The procedures were divided into 4 groups containing 20 surgeries each (I to IV), according to their order, for comparison.

RESULTS

there was no difference in stone sizes between groups. All qualitative variables varied significantly between groups (p<0.001), except between III and IV. In the quantitative analysis, there was a difference between groups I and IV in time for double-J catheter placement (p=0.012). There was an increasing difference in sheath placement time (p<0.001) and in total operative time (p=0.004). The time fot stone treatment (p=0.011) was significant only between groups I, II and III. There was difference in total sheath time only between groups I and III (p=0.023). Stone free status did not change between groups.

DISCUSSION

the differences between the qualitative and quantitative variables show the relation between number of surgeries performed and proficiency in the procedure. Intergroup comparisons show sequential optimization of parameters.

CONCLUSIONS

we found that 60 is a reasonable number of surgeries to be performed in order to reach the plateau of RIRSs learning curve.

A Hybrid Surgical Simulator for Interactive Endoscopic Training

Endoscopy serves as an indispensable minimally-invasive surgical procedure. Due to the limited view and non-intuitive operation of the instrument, the mastery of endoscopic manipulation requires deep medical knowledge as well as complex perception and motor skills of the surgeon. Intensive surgical training is required, and simulation-based training is of more and more importance over traditional animal- or cadaver-based approaches. Here, we developed a hybrid surgical simulator that consists of a realistic physical organ model and an artificial intelligence (AI)-driven cyber model. We built a physical model of the full urinary tract with soft materials and detailed blood vessel structures. Endourological procedures were performed to localize and treat renal calculi by a flexible endoscope. An AI algorithm detects the lesions automatically with high accuracy and provides quantitative feedback about an operator's endoscopic skills. The hybrid simulator system shows great potential as an interactive and personalized learning environment for endoscopic skills. Clinical Relevance- This work establishes a preliminary approach for realistic endoscopic training. The developed hybrid surgical simulator - with high-fidelity physical organ models and quantitative feedback - can deliver effective hands-on learning to surgeons to improve their endoscopic skills.

Learning curves of flexible ureteroscopy (275 cases) and prone percutaneous nephrolithotomy (73 cases) in paediatric stones: data from 348 children

OBJECTIVES

To evaluate learning curves in pediatric flexible ureteroscopy (FURS) and pediatric prone percutaneous nephrolithotomy (PCNL) by a single surgeon with experience in adult endourological procedures.

MATERIALS AND METHODS

Children who were diagnosed with nephrolithiasis and treated with PCNL or FURS from June 2014 to April 2019 were analyzed. Patient demographics, stone characteristics, stone-free rate (SFR), complication rate (CR) were reported. Learning curves were generated to estimate the effect of a surgeon's experience on outcomes.

RESULTS

Seventy-three children underwent PCNL on 86 sides in 77 operations and 275 children underwent FURS on 320 sides in 288 operations. The SFRs were 88.1% (282/320) for FURS procedures and 89.5% (77/86) for PCNL procedures. CRs were 19.8% (57/288) and 35.1% (27/77), respectively. Learning curves showed that the SFRs of the two procedures increased with the accumulation of cases. There was an apparent improvement of SFR for PCNL procedures after about 60 surgeries. A favourable SFR of FURS could be achieved at the start of learning. No apparently decreased CRs were observed for either PCNL or FURS.

CONCLUSIONS

Both PCNL and FURS could achieve satisfactory SFRs and accepted CRs in paediatric stones. Increased surgical experience was associated with improved SFRs of both PCNL and FURS procedures and the surgeon's adult FURS experience translated to paediatric FURS better than adult PCNL experience translated to the paediatric PCNL. A surgeon needs approximate 60 cases of PCNL to achieve competence. For FURS, a favourable SFR could be achieved at the start of learning.

A curva de aprendizado em cirurgia retrógrada intrarrenal: Uma análise prospectiva

RESUMO Introdução: a cirurgia retrógrada intrarrenal (CRIR) é ferramenta em evolução. Sua curva de aprendizado não está bem estabelecida, apesar do uso comum dos ureteroscópios flexíveis atualmente. O objetivo é estimar o número de procedimentos necessários para se realizar CRIR consistentemente. Material e Métodos: Um residente de urologia teve suas primeiras 80 CRIR para tratamento de nefrolitíase analisadas quantitativa e qualitativamente. Os procedimentos foram divididos em 4 grupos contendo 20 cirurgias cada (I a IV), de acordo com sua ordem, para comparação. Resultados: Não houve diferença nos tamanhos dos cálculos entre grupos. Todas as variáveis qualitativas apresentaram variação significativa entre os grupos (p<0,001), exceto entre III e IV. Na análise quantitativa houve diferença entre os grupos I e IV no tempo de colocação do cateter duplo J (p=0,012). Houve uma diferença crescente no tempo de colocação da bainha (p<0,001) e no tempo operatório total (p=0,004). O tempo para o tratamento do cálculo (p=0,011) foi significativo apenas entre os grupos I, II e III. Houve diferença no tempo total de bainha apenas entre os grupos I e III (p=0,023). Taxa livre de cálculos não se alterou entre os grupos. Discussão: as diferenças observadas entres as variáveis qualitativas e quantitativas evidenciam a relação entre o número de cirurgias realizadas e a proficiência no procedimento. As comparações intergrupo mostram otimização sequencial dos parâmetros. Conclusões: estima-se que 60 é um número razoável de cirurgias para que se atinja o platô da curva de aprendizado.

Curva de aprendizado em ureteroscopia semi-rígida em cálculos de pequenas dimensões: quantos casos são necessários?

RESUMO Introdução: ureteroscopia semi-rígida é o procedimento de escolha para o tratamento da ureterolitíase, mas necessita de uma curva de aprendizado para ser executada com segurança. Objetivo: descrever uma estimativa da curva de aprendizado para realização da ureterorrenolitotripsia semi-rígida em pacientes com ureterolitíase de pequena dimensão e estimar o número mínimo de procedimentos necessários para realizar o procedimento cirúrgico com segurança. Métodos: trata-se de um estudo prospectivo avaliando a curva de aprendizado de um residente de urologia nas primeiras 60 ureteroscopias semi-rígidas em pacientes com ureterolitíase até 1cm. Os pacientes foram divididos em três grupos: Grupo I uma a vinte cirurgias, Grupo II vinte e uma a quarenta cirurgias e Grupo III quarenta e uma a sessenta cirurgias. As cirurgias foram gravadas e analisadas por dois urologistas experientes em endourologia. Foi feita uma análise qualitativa baseada em uma ferramenta previamente validada e uma análise quantitativa. Resultados: todas as variáveis qualitativas tiveram variação significativa entre os Grupos I e II (p<0.001), e entre os Grupos I e III (p<0.001). Houve diferença no tempo para acesso ao ureter, passagem de cateter duplo J e tempo operatório total entre os Grupos I e II (p<0.001) e nos Grupos I e III (p<0.001). Conclusão: após 40 casos parece haver pouco incremento tanto na avaliação quantitativa bem como na avaliação qualitativa em performance cirúrgica para a realização de ureterolitotripsia semi-rígida com segurança em cálculos de até 1cm.

Effectiveness of a newly-developed training module using 3D printing for the navigation during retrograde intrarenal surgery

Purpose

This study aimed to evaluate the feasibility of the newly-developed three-dimensional (3D) printed training module for navigation during retrograde intrarenal surgery.

Materials and Methods

Two specialists provided orientation to all trainees. The 3D printing model consisted of eight calyces in each kidney. One navigation time started from the moment when the endoscope entered the ureter. After navigation was completed, the navigation time was recorded. The goal was to perform ten navigation times for each side, starting from the right or the left side at random. After the experiment, all trainees were asked to fill out a questionnaire.

Results

The average training period of all 17 trainees was 3.05±1.80 years. Eleven trainees (64.7%) had the experience of assisting surgery for <100 cases, and six trainees (35.3%) had the experience of assisting surgery for 100 to 500 cases. Nine trainees (52.9%) began training from the right, and eight trainees (47.1%) started from the left. The average navigation time of 308 trials was 153.4±92.6 seconds. The maximum and minimum navigation times were 354.3±177.2 seconds and 80.1±25.6 seconds. The mean navigation time of the first and the last trials of all trainees significantly decreased from 251.4±108.0 seconds to 93.9±33.2 seconds. The average reduction in navigation time was 201.3±133.3 seconds. Almost all trainees were satisfied with the training.

Conclusions

The newly-developed 3D printing navigation training module seems to be adequate to improve surgical skills of flexible ureteroscopy.

Are there predictors of flexible ureteroscopic aptitude among novice trainees? objective assessment using simulation-based trainer

PURPOSE

Non-surgical skills involving hand-eye coordination and bimanual dexterity may have a transferable impact on the acquisition of ureteroscopy skills. In this study, we aim to investigate the predictors of initial flexible ureteroscopy skills among novice trainees.

METHODS

This was a prospective study involving students with no prior ureteroscopy exposure. Non-surgical parameters were assessed with a detailed survey, including demographics, video game, and musical history. Musical ability was objectively evaluated with the mini-Profile of Music Perception Skills test. Ureteroscopic performance was evaluated using a Boston Scientific^© flexible ureteroscope on a bench model. Each participant completed diagnostic ureteroscopy and stone extraction. Outcomes included both speed and quality of performance, based on an Objective Structured Assessment of Technical Skills rubric.

RESULTS

A total of 28 pre-clerkship medical students and 10 urology residents were included. Age and musical background were not associated with ureteroscopic aptitude. Those with video game history tended to perform ureteroscopy tasks faster with a higher OSATS score, although no statistical significance was reached. Male gender was associated with faster task completion with statistically higher OSATS score independent of video game activities (p = 0.011), however, the absolute score difference was small.

CONCLUSIONS

Among novice trainees, musical and video game experience was not predictive of ureteroscopy skills. Male gender was associated with slightly faster and higher ureteroscopy technique scores, however, the differences are small and unlikely to represent clinical significance. Nevertheless, the use of ureteroscopy trainer provides useful insights and should be adopted in training programs as a marker of skills progression.

Introducing 3D printed models of the upper urinary tract for high-fidelity simulation of retrograde intrarenal surgery

PURPOSE

Training in retrograde intrarenal surgery for the treatment of renal stone disease is a challenging task due to the unique complexity of the procedure. This study introduces a series of 3D printed models of upper urinary tract and stones designed to improve the training process.

METHODS

Six different models of upper urinary tract were algorithmically isolated, digitally optimized and 3D printed from real-life cases. Soft and hard stones in different sizes were produced from 3D printed moulds. The models were fitted onto a commercially available part-task trainer and tested for retrograde intrarenal surgery.

RESULTS

Each step of the procedure was simulated with extraordinary resemblance to real-life cases. The unique anatomical intricacy of each model and type of stones allowed us to reproduce surgeries of increasing difficulty. As the case-load required to achieve proficiency in retrograde intrarenal surgery is high, benchtop simulation could be integrated in training programs to reach good outcomes and low complication rates faster. Our models match incredible anatomical resemblance with low production cost and high reusability. Validation studies and objective skills assessment during simulations would allow comparison with other available benchtop trainers and the design of stepwise training programs.

CONCLUSIONS

3D printing is gaining a significant importance in surgical training. Our 3D printed models of the upper urinary tract might represent a risk-free training option to hasten the achievement of proficiency in endourology.

Feasibility, safety, and efficacy of ultrasound-guided transperineal laser ablation for the treatment of benign prostatic hyperplasia: a single institutional experience

PURPOSE

To evaluate the feasibility, safety, and efficacy of ultrasound-guided transperineal laser ablation (TPLA) as a new minimally invasive surgical therapy (MIST) for the treatment of lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Under local anesthesia and conscious sedation up to two laser fibers for each prostatic lobe were inserted under US-guidance by a percutaneous approach. TPLA was performed using a continuous wave diode laser (SoracteLite-EchoLaserX4) able to generate a light-induced thermal heating and subsequent coagulative necrosis of the prostatic tissue. Patients were evaluated at 3, 6, and 12 months after TPLA.

RESULTS

Twenty-two consecutive patients were prospectively enrolled (median age 61.9 years). All procedures were well tolerated and no procedural complications were recorded. Median catheterization time was 7 days, while the median hospitalization time was 1 day. Three out of twenty-two patients (13.6%) experienced acute urinary retention and two (9.1%) of them urinary tract infection requiring major antibiotic treatment. At 3, 6, and 12 months, median prostate volume significantly decreased by a - 21.3%, - 29%, and - 41%, respectively. At the same time point, median IPSS was 8 (- 63.6%), 5 (- 74%), and 6 (- 75%), while median QoL score was 1 in all the scheduled timepoints of follow-up. The median postoperative Qmax at 3, 6, and 12 months improved by + 57.8%, + 98%, and + 115.8%, respectively. Ejaculatory function was preserved in 21 out of 22 patients (95.5%).

CONCLUSIONS

TPLA of the prostate appears to be a promising MIST for BPH. Long-term results and comparative studies against standard treatments are warranted before implementations of this technique in the urologist's armamentarium.

Comparative outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for pediatric kidney stones larger than 2 cm

OBJECTIVES

To compare the outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for pediatric kidney stones larger than 2 cm and to show the learning curves for the two procedures.

METHODS

A prospectively managed database containing pediatric patients with kidney stones larger than 2 cm from June 2014 to October 2019 was analyzed. The primary outcomes were the efficacy and safety of flexible ureteroscopy and mini-percutaneous nephrolithotomy. Data on patient demographics, treatment details, stone-free rate, and complication rate were collected and compared. Learning curves were generated to estimate the effect of the surgeon's experience on surgical outcomes.

RESULTS

The final analysis included 113 pediatric patients who underwent surgery for kidney stones on a total of 126 sides. The stone-free rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy were 80.9% (34/42) and 79.7% (67/84), respectively (P = 0.19). The complication rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy were 52.5% (21/40) and 27.4% (27/73), respectively (P = 0.01). When stone mass was considered, the stone-free rates for mini-percutaneous nephrolithotomy and flexible ureteroscopy for stones with a high mass (>5000 HU*cm² ) were 83.3% (20/24) and 55.5% (10/18), respectively (P = 0.04). The learning curves showed that the stone-free rates for both mini-percutaneous nephrolithotomy and flexible ureteroscopy increased with the accumulation of cases. A higher stone-free rate could be achieved after approximately 20 mini-percutaneous nephrolithotomy cases and after approximately 50 flexible ureteroscopy cases.

CONCLUSIONS

Flexible ureteroscopy has an acceptable stone-free rate and a lower complication rate than mini-percutaneous nephrolithotomy when treating pediatric kidney stones larger than 2 cm. Mini-percutaneous nephrolithotomy is more applicable to stones with a high mass. The stone-free rates achieved after both mini-percutaneous nephrolithotomy and flexible ureteroscopy could be improved with number of cases accumulated.

One- versus two-surgeon active stone retrieval procedures for flexible ureteroscopy: An off-site simulator comparative study

OBJECTIVES

To evaluate the efficacy of the one-surgeon basketing technique compared to the conventional two-surgeon method for flexible ureteroscopy.

METHODS

Seven urologists (three trained and four less-trained surgeons) extracted three renal stones using each technique with an off-site simulator. We analyzed the task completion time, the number of times the basket forceps were opened and closed, and unexpected events during stone-catching, for both techniques.

RESULTS

There was no significant difference in the total task completion time between the one-surgeon (102.0 [interquartile range 63.5-164.0] s) and two-surgeon (99.5 [interquartile range 75.0-145.3] s) techniques. However, the time it took the trained surgeons to extract all stones was significantly shorter with the one-surgeon than with the two-surgeon technique (19.0 [interquartile range 18.0-20.0] s vs 34.0 [interquartile range 25.0-40.0] s; P = 0.049). Among the less-trained surgeons, the opposite effect was observed, but this difference was not statistically significant (96.5 [interquartile range 61.0-134.5] s vs 64.0 [interquartile range 51.5-77.0] s; P = 0.489). The number of times the forceps were opened and closed during stone-catching was significantly lower with the one-surgeon technique than with the two-surgeon technique (5.0 [interquartile range 4.0-5.0] times vs 9.0 [interquartile range 6.0-14.5] times; P = 0.018).

CONCLUSIONS

The one-surgeon technique can offer comparable efficacy to the two-surgeon technique. If surgeons are sufficiently trained, a one-surgeon basketing technique for performing flexible ureteroscopy might become a new technical modality for extracting renal stones.

Retrograde intrarenal surgery: Past, present, and future

With the recent technological advancements in endourology, retrograde intrarenal surgery has become a more popular procedure for treatment of urolithiasis. Furthermore, since the introduction of new laser systems and advanced flexible ureteroscopy with miniaturized ureteroscopes, the treatment indications for retrograde intrarenal surgery have expanded to include not only larger renal stones of >2 cm but also upper urinary tract urothelial carcinoma, ureteral stricture, and idiopathic renal hematuria. Clinicians must keep up with these trends and make good use of these technologies in the rapidly changing field of endourology. Simultaneously, we must consider the risk of various complications including thermal injury due to laser use, ureteral injury caused by the ureteral access sheath, and radiation exposure during retrograde intrarenal surgery with fluoroscopic guidance. This review focuses on the past, present, and future of retrograde intrarenal surgery and provides many topics and clinical options for urologists to consider.

The Learning Curves for Laser Application in Urology Procedures: Review of the Literature

Introduction: Currently, a laser is a popular technology in urological surgeries. The important laserrelated issue is the time when a surgeon reaches an acceptable level of safety and efficacy using laser technology. Methods: In this review, we aimed to assess the learning curves of three types of surgeries in urology, including photoselective vaporization of the prostate (PVP), holmium laser enucleation of the prostate (HoLEP) and retrograde intra-renal surgeries (RIRSs). Here, we searched Medline, Web of Science, Google Scholar, EMBASE, and Scopus for such keywords as Urology, laser, laser vaporization, prostate, nephrolithiasis, benign prostatic hyperplasia (BPH), and learning curve. Results: We evaluated 14 studies about PVP, 17 about RIRS, and 29 studies about HoLEP. Also, we separately discussed the learning curves of these three kinds of surgeries in detail. Conclusion: All the urologists, even expert surgeons, should attend a formal training course and have a skilled tutor present at their first cases.

Ureteral Strictures Following Ureteroscopic Stone Treatment

Background and Purpose: Ureteral stricture is a rare, but serious complication following ureteroscopy (URS) for stones. The aim of this study was to investigate how many patients ended up with a ureteral stricture after URS at our hospital and how these were treated. We also wanted to identify potential risk factors for postendoscopic stricture formation. Materials and Methods: A retrospective evaluation of 1001 URSs for stone treatment at the day-case surgery unit between 2013 and 2018 was performed. Data on pretreatment status, the surgical procedure, and follow-up were recorded. Exact χ² and independent samples t-tests were used comparing data among those who developed strictures and those who did not. Multiple logistic regression was performed analyzing risk factors for stricture formation. Results: In total, 1001 URSs were performed in 725 patients, 289 women and 436 men. Of these, 995 cases were eligible for analysis. At follow-up with CT after 3 months, 28 (3.0%) strictures were identified. Of these, 20 received endourologic treatment with balloon dilatation of which 15 (75%) were effective. Definitive treatment in the 13 patients with failed or unattempted endourologic treatment included nephrectomy, reconstructive surgery, permanent nephrostomy, or observation with no further treatment. In multiple regression analysis, use of ureteral access sheath (UAS; odds ratio [OR] 4.6, p = 0.011), ureteral perforation (OR 11.8, p < 0.0001), and surgical time >60 minutes (OR 5.7, p < 0.005) were found to be risk factors for stricture formation. Conclusion: Ureteral stricture is a rare complication of URS. Balloon dilatation should be the first line of treatment. Use of UAS, perforation, and excessive operating time were found to be risk factors for postendoscopic ureteral stricture formation. Special attention to these risk factors should be given to reduce the incidence of ureteral strictures.

Performance Optimization Strategies for Complex Endourologic Procedures

OBJECTIVE

To identify and address factors that may impact a surgeon's performance during endourologic procedures.

METHODS

A literature review was performed for articles focusing on surgical ergonomics, education, sports and performance psychology.

RESULTS

As urologists and trainees have become more comfortable approaching complex pathology endoscopically, there remains an opportunity to refine surgeon-related factors and optimize extrinsic factors to maximize efficiency and provide patients with the highest quality outcomes and safety.

CONCLUSION

Medical centers and training programs should strive to include formal lessons on stress-coping mechanisms, communication, and dedicated ergonomic training, as these all play a role in physician well-being and may lead to improved clinical outcomes.

Validation of laparoscopy and flexible ureteroscopy tasks in inanimate simulation training models at a large-scale conference setting

Objective

Simulation based training with training models is being increasingly used as a tool to help trainees mount the learning curve. However, validation studies of surgical simulators are often limited by small numbers. We aim to evaluate the feasibility of validating simulation-training tasks in laparoscopy and flexible ureteroscopy (FURS) rapidly at a large-scale conference setting for residents.

Methods

Seventy-six urology residents from various Asian countries were assessed on their laparoscopic and FURS skills during the 14th Urological Association of Asia Congress 2016. Residents performed the peg transfer task from the fundamentals of laparoscopic surgery (FLS) and completed inspection of calyces and stone retrieval using a flexible ureteroscope in an endourological model. Each participant's experience (no experience, 1–30 or >30 procedures) in laparoscopy, rigid ureteroscopy (RURS) and FURS was self-reported.

Results

Median time taken to complete the laparoscopic task decreased with increasing laparoscopic experience (209 s vs. 177 s vs. 145 s, p=0.008) whereas median time taken to complete the FURS tasks reduced with increasing FURS experience (405 s vs. 250 s vs. 163 s, p=0.003) but not with RURS experience (400.5 s vs. 397 s vs. 331 s, p=0.143), demonstrating construct validity. Positive educational impact of both tasks was high, with mean ratings of 4.16/5 and 4.10/5 respectively, demonstrating face validity.

Conclusion

Our study demonstrates construct and face validities of laparoscopy and FURS simulation tasks among residents at a conference setting. Validation studies at a conference setting can be an effective avenue for evaluating simulation models and curriculum in the future.

Reducing kidney motion: optimizing anesthesia and combining respiratory support for retrograde intrarenal surgery: a pilot study

BACKGROUND

One of the greatest challenges presented with RIRS is the potential for movement of the stone within the operative field associated with diaphragm and chest respiratory excursions due to mechanical ventilation. To overcome this challenge, we propose in this pilot study a new general anesthesia technique combining high frequency jet ventilation (HFJV) with small volume mechanical ventilation (SVMV). Data regarding safety, feasibility and surgeons' impression was assessed.

METHODS

Patients undergoing RIRS for kidney stones from November 2017 to May 2018 were prospectively recruited to participate in the study. In each case after the beginning of general anesthesia (GA) with mechanical ventilation (MV) surgeons were asked to assess the mobility of the operative field and conditions for laser lithotripsy according to the developed questionnaire scale. The questionnaire consisted of 5 degrees of assessment of kidney mobility and each question was scored from 1 to 5, 1 being very mobile (extremely poor conditions for dusting) and 5 completely immobile (Ideal conditions for dusting). After the assessment GA was modified with combined respiratory support (CRS), reducing tidal volume and respiratory rate (small volume mechanical ventilation, SVMV) and applying in the same time transcatheter high frequency jet ventilation (HFJV) inside the closed circuit. After beginning of CRS, surgeons were once again asked to assess the mobility of the operative field and the conditions for laser lithotripsy. Main ventilation parameters were recorded and compared in both regimens.

RESULTS

A total of 38 patients were included in the study. The mean age was 49 (range 45-53) with a mean stone size of 10 mm (range 10-14) and Hounsfield unit of 1060 (range 930-1190). All patients underwent successful RIRS and no intraoperative complications occurred throughout the duration of the study. A statistically significant difference between ventilation parameters prior to and after CRS institution was detected in all cases, however their clinical impact was negligible. Despite this, assessment via the questionnaire scale point values varied significantly before and after the application of CRS and were 2.3 (2.1; 2.6) and 3.8 (3.7; 4.0) respectively (p < 0.001).

CONCLUSIONS

The novel combined respiratory approach consisting of HFJV and SVMV appears to provide better conditions for stone dusting through reduced respiratory kidney motion and is not associated with adverse health effects or complications.

TRIAL REGISTRATION

NCT03999255 , date of registration: 25th June 2019 (retrospectively registered).

Core Professionalism Education in Surgery: A Systematic Review

BACKGROUND

Professionalism education is one of the major elements of surgical residency education.

AIMS

To evaluate the studies on core professionalism education programs in surgical professionalism education.

STUDY DESIGN

Systematic review.

METHODS

This systematic literature review was performed to analyze core professionalism programs for surgical residency education published in English with at least three of the following features: program developmental model/instructional design method, aims and competencies, methods of teaching, methods of assessment, and program evaluation model or method. A total of 27083 articles were retrieved using EBSCOHOST, PubMed, Science Direct, Web of Science, and manual search.

RESULTS

Eight articles met the selection criteria. The instructional design method was presented in only one article, which described the Analysis, Design, Development, Implementation, and Evaluation model. Six articles were based on the Accreditation Council for Graduate Medical Education criterion, although there was significant variability in content. The most common teaching method was role modeling with scenario- and case-based learning. A wide range of assessment methods for evaluating professionalism education were reported. The Kirkpatrick model was reported in one article as a method for program evaluation.

CONCLUSION

It is suggested that for a core surgical professionalism education program, developmental/instructional design model, aims and competencies, content, teaching methods, assessment methods, and program evaluation methods/models should be well defined, and the content should be comparable.

Toward Respiratory-Gated Retrograde Intrarenal Surgery: A Prospective Controlled Randomized Study

INTRODUCTION

We set out to investigate whether general anesthesia with low ventilation (LV, respiratory rate ≤8/minute and tidal volume <500 mL) could reduce renal mobility and thereby facilitate improved retrograde intrarenal surgery (RIRS) compared with general anesthesia with standard ventilation (SV).

MATERIALS AND METHODS

All 60 consecutive patients who presented for RIRS in our department from September 1, 2017 to December 31, 2017 were prospectively randomized 1:1 into one group that was selected to receive SV and another that received LV. Significant factors influencing the study endpoints considered fragmentation rate (FR), removal rate (RR), processing rate (PR), and operating rate (OR), were statistically analyzed for the whole group as well as for comparison by level of surgeon expertise.

RESULTS

Univariate analysis revealed that LV was a significant factor in improving all endpoints. Some endpoints were also affected by the stone's volume, number, and density as well as the surgeon expertise. LV remained the single independent factor for FR, RR, and PR in the multivariate analysis. LV significantly improved all four of the fellows' endpoints (p < 0.05 for each) and positively influenced the expert's RR (p = 0.04), PR (p = 0.02) and OR (p = 0.04). The performance gap between the fellows and the experts narrowed under LV. The end-tidal CO₂ was significantly higher in the LV group (50 vs 36 mm Hg; p < 0.0001), however, without any clinical significance. The overall stone-free rate (97%) and complication rate (5%) were not significantly different between the two groups. The patient's anesthesia-related safety was not affected by the mode of ventilation as evidenced by no need to convert from LV to SV during the procedures.

CONCLUSIONS

LV during RIRS has a significant positive impact on the overall improvement of surgical performance and effectiveness. It does not negatively affect the patient's anesthesia-related safety and may contribute to considerably improving the performance of in-training endourologists.

Impact of surgeon's experience on outcome parameters following ureterorenoscopic stone removal

Within the BUSTER trial, we analyzed the surgeon's amount of experience and other parameters associated with URS procedures regarding the stone-free rate, complication rate, and operative time. Patient characteristics and surgical details on 307 URS procedures were prospectively documented according to a standardized study protocol at 14 German centers 01-04/2015. Surgeon's experience was correlated to clinical characteristics, and its impact on the stone-free rate, complication rate, and operative time subjected to multivariate analysis. 76 (25%), 66 (21%) and 165 (54%) of 307 URS procedures were carried out by residents, young specialists, and experienced specialists (> 5 years after board certification), respectively. Median stone size was 6 mm, median operative time 35 min. A ureteral stent was placed at the end of 82% of procedures. Stone-free rate and stone-free rate including minimal residual stone fragments (adequate for spontaneous clearance) following URS were 69 and 91%, respectively. No complications were documented during the hospital stays of 89% of patients (Clavien-Dindo grade 0). According to multivariate analysis, experienced specialists achieved a 2.2-fold higher stone-free rate compared to residents (p = 0.038), but used post-URS stenting 2.6-fold more frequently (p = 0.023). Surgeon's experience had no significant impact on the complication rate. We observed no differences in this study's main endpoints, namely the stone-free and complication rates, between residents and young specialists, but experienced specialists' stone-free rate was significantly higher. During this cross-sectional study, 75% of URS procedures were performed by specialists. The experienced specialists' more than two-fold higher stone-free rate compared to residents' justifies ongoing efforts to establish structured URS training programs.

Worldwide Trends of Urinary Stone Disease Treatment Over the Last Two Decades: A Systematic Review

INTRODUCTION

Numerous studies have reported on regional or national trends of stone disease treatment. However, no article has yet examined the global trends of intervention for stone disease.

METHODS AND MATERIALS

A systematic review of articles from 1996 to September 2016 for all English language articles reporting on trends of surgical treatment of stone disease was performed. Authors were contacted in the case of data not being clear. If the authors did not reply, data were estimated from graphs or tables. Results were analyzed using SPSS version 21, and trends were analyzed using linear regression.

RESULTS

Our systematic review yielded 120 articles, of which 8 were included in the initial review. This reflected outcomes from six countries with available data: United Kingdom, United States, New Zealand, Australia, Canada, and Brazil. Overall ureteroscopy (URS) had a 251.8% increase in total number of treatments performed with the share of total treatments increasing by 17%. While the share of total treatments for percutaneous nephrolithotomy (PCNL) remained static, the share for extracorporeal shockwave lithotripsy and open surgery fell by 14.5% and 12%, respectively. There was significant linear regression between rising trends of total treatments year on year for URS (p < 0.001).

CONCLUSION

In the last two decades, the share of total treatment for urolithiasis across the published literature has increased for URS, stable for PCNL, and decreased for lithotripsy and open surgery.

New Advanced Bench Model for Flexible Ureteroscopic Training: The Smart Simulator

Smart Simulator is a new advanced bench training model for achieving proficiency in flexible ureteroscopy (fURS). Its important features are portability and the ability to simulate breathing-induced kidney movements, model pyelocalices similar to those in humans, create a situation closely resembling a fURS field, and create papillae of a size equivalent to that of the access sheath. Smart Simulator thus creates a situation more closely resembling that in a clinical setting than the other bench training models for fURS. Sixteen urologists experienced in fURS assessed the Smart Simulator for face validity and content validity. The model was acceptable in terms of realism, acceptability, and feasibility. Trainees can use it to practice laser manipulation for kidney stone fragmentation and retrieval in accord with breathing-induced movements and various other created fields sometimes confronted during fURS. Training in situations in nearly real fURS surgical fields may improve trainees' technical skills.

Establishment and Evaluation of Patient-Specific Virtual Ureteroscopy in Assisting Flexible Ureteroscopy for Urolithiasis

Objectives. To establish virtual ureteroscopy (VU) through computed tomography urography (CTU) data from patients with upper urinary tract (UUT) stones indicated for flexible ureteroscopy (fURS) and to validate its effectiveness. Methods. Patient-specific VU generation was accomplished through incorporating CTU data into specialized software (Crusher) developed on the open access Visualization Tools Kit (VTK). These were then presented to fURS experts and novice urologists for evaluation and comparison using modified Likert-type questionnaire of 10-point rating scales (1 = not at all useful/not at all realistic/poor, 10 = very useful/very realistic/ excellent). Results. Face and content validation of VU from 5 fURS experts in 3 different centers: overall usefulness 7.4 ± 0.5, graphics 7.4 ± 0.5, intrarenal anatomy 8.4 ± 0.5, stone details 7.8 ± 0.4, usefulness in surgical planning and training 7.6 ± 0.9. Significant increase of detection in the number of calyces and stones was found from using CTU only to CTU-VU combined in the novice group ( P = .000). Before VU observation, novices found much fewer calyces and stones than experts ( P = .004 and .000, respectively). However, this gap disappeared after VU observation ( P = .327 and .292, respectively). VU feedback from the novices was superb. Conclusions. Establishing patient-specific VU through CTU data from renal stone patients is feasible. The present VU can significantly improve novice urologists’ comprehension of intrarenal anatomy and stone information before fURS procedures. Face and content validity is also proved. This novel modality may serve as an important tool for fURS surgical planning, navigation, and training.

Ureteroscopic skills with and without Roboflex Avicenna in the K-box® simulator

Introduction

The aim of this study was to evaluate the acquisition of basic ureteroscopic skills with and without Roboflex Avicenna by subjects with no prior surgical training.

Material and methods

Ten medical students were divided in two groups: Group 1 was trained with Roboflex Avicenna and Group 2 with flexible ureteroscope alone, using the K-box^® simulator model. Participants were scored on their ability to perform or not two exercises, recording the time. In addition, the participants were evaluated on the quality of their performance for the following parameters: respect of the surrounding environment, flow of the operation, orientation, vision centering and stability.

Results

The first exercise was completed only by three and four out of five of students in Group 1 and Group 2, respectively. Stability with the scope was significantly more accurate in the first group compared with the second (P = 0.02). There were no differences in timing, flow or orientation between groups. Although not significant, a tendency of respecting the surrounding tissue and maintaining centered vision was perceived more in the first group. As for the second exercise, there were no differences between groups in regard of orientation, flow, respecting the surrounding tissue, stability or the ability of maintaining centered vision. Although not significant, the second group had a tendency of performing the exercise faster.

Conclusions

According to these preliminary results, the acquisition of basic ureteroscopic skills with and without robotic fURS in the K-box^® simulator, by subjects with no prior surgical training, is similar.

Evaluation of ureteroscopy outcome in a teaching hospital

OBJECTIVE

To evaluate factors affecting semi-rigid ureteroscopy (URS) results highlighting the influence of teaching on its outcomes.

MATERIAL AND METHODS

We reviewed the files of 891 adult patients who had undergone 1182 ureteroscopies at our institute during the period from July 2008 to June 2011. The outcomes of all URSs were evaluated. Outcomes were measured by stone- free rate and presence of complications, which were assessed using the Clavien-Dindo system. Patients were divided into 2 groups; Group 1 (favorable outcome) became stone- free after the first URS and had no documented complications, while Group 2 (unfavorable outcome) had residual stones and/or complications. Group 2 was subdivided according to the skill level of the operating surgeon into two subgroups. Patients belonging to subgroup A had their procedures performed by urology trainees under direct supervision of expert urologists, while those in subgroup B had their procedures performed by the expert urologists themselves. All groups were compared using univariate (chi-square and t tests) and multivariate (logistic regression) statistical tests to identify significant risk factors. All data was analyzed using SPSS.

RESULTS

A total of 1182 URSs were evaluated. 958 patients had a favorable outcome (Group 1) while 224 patients had an unfavorable outcome (Group 2). Factors associated with an unfavorable outcome include location of the presenting stone (p<0.001) and presence of stone impaction (p<0.001). No statistically significant differences were detected in the overall complication rate between trainees and expert urologists. Trainees stone- free rate was comparable to that of experts; 90.3% vs. 91.1%, respectively, p=0.6.

CONCLUSION

Factors such as stone impaction and proximal location are associated with an unfavorable surgical outcome. In a high- volume teaching hospital, semi-rigid URS done by trainees under direct supervision is safe and their outcome is comparable to literature findings.

The surgical experience influences the safety of retrograde intrarenal surgery for kidney stones: a propensity score analysis

The aim of this study is to evaluate if surgical experience could influence the outcomes of retrograde intrarenal surgery (RIRS) in terms of stone clearance and complication rate. Patients from five institutions were included in this study. Patients were divided into two groups. Group 1: patients treated by three surgeons in the early phase of learning curve (surgical experience <100 procedures); Group 2: cases operated by two surgeons with great endourological experience (>400 procedures). Patients and stone characteristics, outcome and complications were analyzed. Multivariable regression model was used. Differences between groups were estimated using propensity scores to adjust for the bias inherent to the different characteristics. 381 RIRS were analyzed (Group 1: 150 RIRS; Group 2: 231 RIRS). Clinical data and stone parameters were comparable. The SFR was 70 % in Group 1 and 77.9 % in Group 2 (p = 0.082). Operative time was significantly shorter in the Group 2 (76.3 vs. 53.1 min, p = 0.001). The overall complication rate was significantly lower in Group 2 (20.7 vs. 8.7, p = 0.001). At unadjusted analysis, a non-significant difference was found between centers on SFR (OR 1.51 95 % CI 0.95-2.41). Conversely, a significant difference was found on overall complications (OR 0.36 95 %CI 0.20-0.67) with lower overall complication in Group 2. This study shows that surgeon experience influences the outcomes of RIRS mainly in terms of safety. Further studies will be needed to assess the exact number of procedures necessary to obtain a plateau in the rate of complications and success.

The effect of ureteroscope size in the treatment of ureteral stone: 15-year experience of an endoscopist

OBJECTIVE

We aimed to investigate the ureter stone treatment results performed by using different- caliber semirigid ureteroscopes (URS).

MATERIAL AND METHODS

Adult patients who were treated for ureteral stones by a single endoscopist between January 2000 and March 2015 were analyzed. The patients were divided into 3 groups in accordance with the caliber of the ureteroscope used: 10/10.5 F Storz (Karl Storz, Tuttlingen, Germany) (January 2002-January 2005) URS was used in group 1, 8.9/9.8 F Storz (February 2005-December 2011) URS was used in group 2, and 6/7.5 FWolf (Richard Wolf, Knittlingen, Germany) (January 2012-March 2015) URS was used in group 3. Patients' age and gender, size and site of stones, stone-free rates (SFR), intra- and perioperative complication rates, and durations of surgery were compared among the groups. Intraoperative complications were classified according to modified Satava, and perioperative complications were classified according to modified Clavien classification systems.

RESULTS

A total of 2461 patients treated for ureteral stones were analyzed. There were 583 patients in group 1 (10/10.5 F Storz), 1302 patients in group 2 (8.9/9.8 F Storz), and 576 patients in group 3 (6/7.5 F Wolf). SFR were 83.7%, 87.4%, and 92.2% in groups 1, 2, and 3, respectively (p=0.01). Duration of surgery was 30.34±10.36 min in group 1, 31.61±10.10 min in group 2, and 42.40±7.35 min in group 3 (p=0.01). The overall complication rates classified according to modified Satava classification were 10.8%, 7.6%, and 6.9% (p=0.01) while grade 3 modified Satava complication rates were 1.9%, 1.5%and 0.5% in groups 1, 2, and 3, respectively (p=0.01).

CONCLUSION

In this study, we found that more frequent use of a small- caliber URS resulted in a longer duration of surgery and an increased rate for JJ stent insertion, however it facilitated a safer and more successful ureteroscopy procedure.

Impact of surgical experience on stone-free rates of ureteroscopy for single urinary calculi of the upper urinary tract: a matched-paired analysis of 600 patients

INTRODUCTION

To evaluate the impact of surgical experience on ureteroscopic stone-free rates (SFR) and complication rates (CR) for the treatment of urinary calculi of the upper urinary tract.

METHODS

We evaluated retrospectively, patients (n=300) having undergone ureteroscopy (URS) for single urinary calculi treated by residents (n=12) at our department over a 6-year period. These patients were matched according to age, gender, body-mass index, and stone side/size/site with patients (n=300) treated by consultants (n=5) of our department during the same period. Patient data, primary SFR, and CR were compared.

RESULTS

The mean±standard deviation (range) stone size was 6.39±3.26 (2-20) mm. The primary SFR after one URS procedure was 95.2% and did not differ between residents and consultants (95% vs 95.3%, p=0.489). The SFR were 95.9% and 98.5% for ureteral stones (p=0.125) and 93.2% and 89.3% for kidney stones (p=0.298) in the resident and consultant group, respectively. The SFR differed significantly between ureteral and kidney stones (97.2% vs 91.3%, p≤0.001). Perioperative complications occurred in a total of 63 patients (10.5%): Clavien 1: 3.8%, Clavien 2: 2%, Clavien 3a: 1.8%, and Clavien 3b: 2.8%, respectively. There were no differences in the total CR between residents (12%) and consultants (9%) (p=0.2116). However, the ureteral perforation rate was significantly higher in residents compared with consultants (4.3% vs 1.3%, p≤0.027).

CONCLUSIONS

URS is a safe and efficacious procedure for the treatment of single urinary calculi. Resident status does not compromise the SFR after ureteroscopic treatment of single urinary calculi. However, the incidence of ureteral perforation was associated with surgeon's experience.

Validation of a high-fidelity model in ureteroscopy incorporating hand motion analysis

PURPOSE

To establish the construct validity of a semirigid ureteroscopy in a high-fidelity simulation model, incorporating hand motion analysis as a paramount part of evaluation.

METHODS

Participants were divided into 3 groups: group 1 (9 junior residents, without experience in ureteroscopy), group II (9 senior residents, with variable experience in ureteroscopy) and group III (2 experts in endourologist); each group performed a single practice session in the high-fidelity bench model, which was previously prepared with small urinary stone phantom in the mid-ureter. Assessment was done using motion tracking device (ICSAD). Procedures were recorded in external vision and endoscopic vision and scored by two blinded evaluators using a Global Rating Scale and ureteral checklist (OSATS).

RESULTS

Significant differences were observed in time taken, path length, numbers of movements, Global Rating Scale and checklist in favor of the experts group. Subanalysis demonstrated no relevant differences between groups II and III in general dexterity parameters except for the non-dominant hand, where experts showed a significant less number of movement (34 vs 221; p = 0.03) and path length (12.1 vs 45.1; p = 0.03). The interrater reliability of the GRS was excellent (0.81; p < 0.001), while for checklist ICC was moderate (0.45; p = 0.03).

CONCLUSIONS

The incorporation of ICSAD into the construct validity of this ureteroscopy model complements traditional methods used to achieve construct validity (OSATS). To our knowledge, this study is the first report using motion analysis as a tool for performance evaluation in a simulated endourological procedure.

Comparative effectiveness and safety of various treatment procedures for lower pole renal calculi: a systematic review and network meta-analysis

OBJECTIVE

To compare the effectiveness of various treatments used for lower pole renal calculi.

METHODS

We searched PubMed, EMBASE, CINAHL, the Cochrane Collaboration's Database of Systematic Reviews, the Cochrane Collaboration Central Register of Controlled Clinical Trials as well as ClinicalTrials.gov for reports up to 1 April 2014. The search was supplemented with abstract reports from various urology conferences. All randomised, 'blinded' clinical studies including patients treated for lower pole renal calculi of <20 mm were included for review. Two authors independently reviewed 5 194 articles, and identified and selected 13 trials for analysis. Network meta-analysis was performed to generate comparative statistics, while quality was assessed with the Jadad composite scale and risk of bias.

RESULTS

All treatment methods examined: percutaneous nephrolithotomy (PNL), ureterorenoscopy (URS) and extracorporeal shockwave lithotripsy (SWL) with an adjuvant therapy (such as inversion, hydration and forced diuresis) were more effective than SWL therapy alone, with risk ratios (95% confidence intervals) of being stone free of: PNL 2.19 (1.62-2.96); URS 1.23 (1.03-1.48); and SWL with an adjuvant therapy 1.30 (1.03-1.63). However, patients treated with the other treatment methods also had a higher risk of adverse events (AEs) compared with SWL, but there was no evidence of a convincing difference between the various techniques and AEs.

CONCLUSION

In stones of <10 mm, SWL with an adjuvant therapy appears to have better stone clearance, lower risk of AEs, and need for further treatment. PNL was most effective treating larger stones, after considering both effectiveness and safety of treatment. These should be considered by both physicians and patients alike when considering the choice of treatment and in the revision of clinical practice guidelines.

Effects of simulation-based training in gastrointestinal endoscopy: a systematic review and meta-analysis

BACKGROUND & AIMS

Simulation-based training (SBT) in gastrointestinal endoscopy has been increasingly adopted by gastroenterology fellowship programs. However, the effectiveness of SBT in enhancing trainee skills remains unclear. We performed a systematic review with a meta-analysis of published literature on SBT in gastrointestinal endoscopy.

METHODS

We performed a systematic search of multiple electronic databases for all original studies that evaluated SBT in gastrointestinal endoscopy in comparison with no intervention or alternative instructional approaches. Outcomes included skills (in a test setting), behaviors (in clinical practice), and effects on patients. We pooled effect size (ES) using random-effects meta-analysis.

RESULTS

From 10,903 articles, we identified 39 articles, including 21 randomized trials of SBT, enrolling 1181 participants. Compared with no intervention (n = 32 studies), SBT significantly improved endoscopic process skills in a test setting (ES, 0.79; n = 22), process behaviors in clinical practice (ES, 0.49; n = 8), time to procedure completion in both a test setting (ES, 0.79; n = 16) and clinical practice (ES, 0.75; n = 5), and patient outcomes (procedural completion and risk of major complications; ES, 0.45; n = 10). Only 5 studies evaluated the comparative effectiveness of different SBT approaches; which provided inconclusive evidence regarding feedback and simulation modalities.

CONCLUSIONS

Simulation-based education in gastrointestinal endoscopy is associated with improved performance in a test setting and in clinical practice, and improved patient outcomes compared with no intervention. Comparative effectiveness studies of different simulation modalities are limited.