Three Dimensional Printing Technology Used to Create a High-Fidelity Ureteroscopy Simulator: Development and Validity Assessment (Rein-3D-Print-UroCCR-39).

OBJECTIVE: To create and assess the validity of a high-fidelity, three dimensional (3D) printed, flexible ureteroscopy simulator resulting from a real case. METHODS: A patient's CT scan was segmented to obtain a 3D model in .stl format, including the urinary bladder, ureter and renal cavities. The file was printed and a kidney stone was introduced into the cavities. The simulated surgery consisted of monobloc stone extraction. Nineteen participants split into 3 groups according to their level (6 medical students, 7 residents and 6 urology fellows) performed the procedure twice at a 1-month interval. They were rated according to a global score and a task-specific score, based on an anonymized, timed video recording. RESULTS: Participants demonstrated a significant improvement between the 2 assessments, both on the global score (29.4 vs 21.9 points out of 35; P < .001) and the task-specific score (17.7 vs 14.7 points out of 20; P < .001) as well as procedure time (498.5 vs 700 seconds; P = .001). Medical students showed the greatest progress for the global score (+15.5 points (mean), P = .001) and the task-specific score (+6.5 points (mean), P < .001). 69.2% of participants considered the model as visually quite realistic or highly realistic and all of them judged it quite or extremely interesting for intern training purposes. CONCLUSION: Our 3D printed ureteroscopy simulator was able to enhance the progress of medical students who are new to endoscopy, whilst being valid and reasonably priced. It could become part of a training program in urology, in line with the latest recommendations for surgical education.

Contemporary assessment of the correlation between Bosniak classification and histological characteristics of surgically removed atypical renal cysts (UroCCR-12 study).

PURPOSE: To evaluate and compare pathological characteristics of renal cysts Bosniak IIF, III and IV in light of recent histological classification. PATIENTS AND METHODS: The French research network for kidney cancer UroCCR conducted a multicentre study on patients treated surgically for a renal cyst between 2007 and 2016. Independent radiological and centralized pathological reviews were performed for every patient. Pathological characteristics were compared to the Bosniak classification. RESULTS: Of a total 216 patients included, 175 (81.0%) tumours (90.9% of Bosniak IV, 69.8% of Bosniak III) were malignant or had a low malignant potential, with 60% of clear cell renal cell carcinoma (CCRCC), 24% of papillary RCC (PRCC) and 6.9% of multilocular cystic renal tumour of low malignant potential (MCRTLMP). Malignancies were mostly of low pT stage (86.4% of pT1-2), and low ISUP grade (68.0% of 1-2). Bosniak III cysts had a lower rate of CCRCC (46.7 vs. 67.3%), higher rate of PRCC (30 vs. 20.9%) and MCRTLMP (18.3 vs. 0.9%) compared to Bosniak IV (p < 0.001). Low-malignant potential lesions were less likely Bosniak IV and pT3-4 stage was more frequent in Bosniak IV vs. III (15.7 vs. 3.5%; p = 0.04). There were two recurrences (1.1%) and no cancer-related death occurred during follow-up. CONCLUSION: These results confirmed that cystic renal malignancies have excellent prognosis. Bosniak III cysts had a low malignant potential, which suggests surveillance could be an option for these lesions.

How accurate is dynamic contrast-enhanced MRI in the assessment of renal glomerular filtration rate? A critical appraisal.

PURPOSE: To evaluate the current literature to see if the published results of MRI-glomerular filtration rate (GFR) stand up to the claim that MRI-GFR may be used in clinical practice. Claims in the current literature that Gadolinium (Gd) DTPA dynamic contrast enhanced (DCE) MRI clearance provides a reliable estimate of glomerular filtration are an overoptimistic interpretation of the results obtained. Before calculating absolute GFR from Gd-enhanced MRI, numerous variables must be considered. MATERIALS AND METHODS: We examine the methodology in the published studies on absolute quantification of MRI-GFR. The techniques evaluated included the dose and volume of Gd-DTPA used, the speed of injection, acquisition sequences, orientation of the subject, re-processing, conversion of signal to concentration and the model used for analysis of the data as well as the MRI platform. RESULTS: Claims in the current literature that using DCE MRI "Gd DTPA clearance provides a good estimate of glomerular filtration" are not supported by the data presented and a more accurate conclusion should be that "no MRI approach used provides a wholly satisfactory measure of renal GFR function." CONCLUSION: This study suggests that DCE MRI-GFR results are not yet able to be used as a routine clinical or research tool. The published literature does not show what change in DCE MRI-GFR is clinically significant, nor do the results in the literature allow a single DCE MRI-GFR measurement to be correlated directly with a multiple blood sampling technique.