Training for percutaneous renal access on a virtual reality simulator

Background The need to develop new methods of surgical training combined with advances in computing has led to the development of virtual reality surgical simulators. The PERC MentorTM is designed to train the user in percutaneous renal collecting system access puncture. This study aimed to validate the use of this kind of simulator, in percutaneous renal access training. Methods Twenty-one urologists were enrolled as trainees to learn a fluoroscopy-guided percutaneous renal accessing technique. An assigned percutaneous renal access procedure was immediately performed on the PERC MentorTM after watching instruction video and an analog operation. Objective parameters were recorded by the simulator and subjective global rating scale （GRS） score were determined. Simulation training followed and consisted of 2 hours daily training sessions for 2 consecutive days. Twenty-four hours after the training session, trainees were evaluated performing the same procedure. The post-training evaluation was compared to the evaluation of the initial attempt. Results During the initial attempt, none of the trainees could complete the appointed procedure due to the lack of experience in fluoroscopy-guided percutaneous renal access. After the short-term training, all trainees were able to independently complete the procedure. Of the 21 trainees, 10 had primitive experience in ultrasound-guided percutaneous nephrolithotomy. Trainees were thus categorized into the group of primitive experience and inexperience. The total operating time and amount of contrast material used were significantly lower in the group of primitive experience versus the inexperience group （P=0.03 and 0.02, respectively）. Conclusions The training on the virtual reality simulator, PERC MentorTM, can help trainees with no previous experience of fluoroscopy-guided percutaneous renal access to complete the virtual manipulation of the procedure independently. This virtual reality simulator may become an important training and evaluation tool in teaching fluoroscopy-guided percutaneous renal access.

Percutaneous renal artery angioplasty and stenting for pulmonary edema caused by Takayasu's arteritis:A case report

Takayasu arteritis （TA） commonly occurs in woman younger than 50 years old and can manifest as isolated, atypical and/or catas- trophic disease. The disease can implicate in any or all of the major organs I As a chronic relapsing and remitting disorder, the overall 10-year survival rate is approximately 90%; however, this rate is reduced in the presence of major complications. The overall mortality rate of TA depends on the severity of the le- sions and involved organs.

Prognostic indicator by urinary microglobulin after renal stenting

Objective To evaluate the effect of revascularization of the renal artery on urinary microglobulin in patients with coronaryartery disease and significant renal artery stenosis(RAS).Methods Forty-four patients with coronary artery disease and severe RAS(luminal narrowing>70%)underwent percutaneous transluminal renal artery angioplasty(PTRA)and stenting,as well as percutaneous coronary intervention.The urine-microglobulin(α_(1)-MG)andβ_(2)-Cmicroglobulin(β_(2)-MG)at baseline and at 3 months after the procedures were measured.Procedural success rate,procedural complications,serum creatinine concentration at baseline and at 3-months were also recorded.Results At 3-months after the renal revascularization therapy,there was no significant change of urineα_(1)-MG ompared with that of the baseline,however,the urineβ_(2)-MG decreased significantly 3-months after the treatment(237±187μg/L vs 377±173μg/L,P<0.01).Multivariate analysis revealed that persistent elevation of urine was an independent predictor of severe events(including re-admission and renal failure)after renal revascularization therapy in patients with severe RAS(OR=3.01,95%CI 1.01-8.95,P=0.036).Conclusions In patients with coronary artery disease and severe RAS,revascularization with PTRA and stenting may improve renal tubular function,but a continuous high level of urinary microglobulins after intervention is associated with more frequent re-hospitalization and renal failure.

Main Renal Artery Plus Branch Ablation in the Treatment of Resistant Hypertension with Renal Denervation

Objective:To study the safety and effi cacy of denervation of renal artery branches in the treatment of resistant hy-pertension.Methods:Sixty patients with resistant hypertension were enrolled.The patients were randomly assigned to the main renal artery plus branch ablation group or the main renal artery ablation group.The clinical data and operation-related parameters,including number of ablation points,temperature,and average energy,were recorded.Ambulatory blood pressure was taken for all patients at the baseline and at 6 months after treatment.Offi ce blood pressure was recorded before treatment and after treatment every 3 months for 2 years.Results:Sixty patients with resistant hypertension were enrolled in this study.There were 30 patients in each group.Angiography was performed after ablation.No renal artery complications,such as stenosis and dissection,occurred in the two groups.There was no signifi cant difference in age,sex,BMI,comorbid disease,and medication between the two groups(P>0.05).The number of ablation points for the main renal artery plus branch ablation group was greater than that for the main renal artery ablation group.The offi ce blood pressure and 24-hour blood pressure were signifi cantly lower 6 months after treatment than before treatment in both groups(P<0.05).Offi ce blood pressure in the main renal artery plus branch ablation group was lower than that in the main renal artery ablation group during the 3-12-month follow-up period,with a statistical difference.However,as the follow-up time increased,the difference disappeared.Conclusion:The results of this study show that main renal artery plus branch ablation is a safe interventional method,but there was no obvious advantage on long-term follow-up compared with only main renal artery ablation.

Post-Renal Biopsy Deglobulization: Risk Factors and Prognosis: A Study of 157 Biopsies

Introduction: Percutaneous renal biopsy (PRB) is the gold standard for the diagnosis of most renal diseases. It is a safe and effective modality for the collection of renal tissue. However, many safety measures are not based on sufficient evidence and therefore vary considerably from a center to another. The aim of this work is to determine the rate of bleeding complications, to identify the risk factors for these complications, and to clarify the post renal biopsy prognosis. Materials and Methods: We performed a single-center retrospective observational study in the nephrology department at the University Hospital of Fez, including all patients who underwent percutaneous renal biopsy on native kidney between January 2018 and December 2019. Results: Overall, 157 biopsies were performed. Deglobulization was present in 20.4% (40) of patients, the mean age of patients was 41.57 ± 16.11 years [16.78]. The sex ratio M/F: 1.22. Diabetes mellitus was present in four cases (11.1%), arterial hypertension was present in four cases (11.1%). On clinical examination, systolic hypertension was found in 45.7%, diastolic hypertension in 45%, antihypertensive therapy was initiated in all patients with hypertension before. Hyperuremia was present in 29 patients (80.6%), renal failure was present in 77.8%. Anemia was present in 55.6%, thrombocytopenia in six cases (16.7%). Radiologically, the size of the kidneys was reduced in 5 patients (17.2%), differentiation was limited in 5 patients (17.2%). Major complications occurred in 3.8% (6/157). These six patients had a lumbar pain and required blood transfusions. A radiological embolization procedure was indicated in only one patient. Minor complications were seen in 21.6% (34/157). The diagnoses that were retained in patients with deglobulization were: Lupus in 34.71%, pauci-immune vasculitis in 13.79%, membranous glomerulonephritis in 10.34%, focal and segmental hyalinosis in 10.34%, membrano-proliferative glomerulonephritis in 10.34%. In univariate and multivariate analysis, the major risk factors for deglobulization found in our patients were: hyperuremia 80.6% (p: 0.017), acute renal failure 77.8% (p: 0.04), acute hemodialysis 24.7% (p: 0.02), hyperphosphatemia 63.6% (0.04). Conclusion: Renal biopsies are an overall safe procedure with rare major complications. Post-renal biopsy deglobulization is common. Routine post-biopsy ultrasound may not be necessary. Renal biopsies can be performed safely if risk factors are controlled, such as renal failure, hyperuremia, hyperphosphatemia, hemodialysis patients and a diagnosis of lupus nephropathy.

Mini versus ultra-mini percutaneous nephrolithotomy in a paediatric population

Objective:To evaluate whether there would be a difference in outcome when the smaller ultra-mini 12 Fr sheath was used instead of the mini 16 Fr sheath for percutaneous nephrolithotomy(PCNL)in paediatric patients for stones less than 25 mm.Methods:This was a prospective cohort study of patients who underwent PCNL in our hospital in a 2-year period from July 2016 to June 2018 by a single surgeon.PCNL was performed in a prone position and tract was dilated to the respective size using single step dilatation.Laser was used to fragment the stone.Stone-free outcome was defined as absence of stone fragment at 3 months on kidney,ureter,and bladder X-ray.Results:There were 40 patients in each group.Mean stone size was comparable between the two groups(14.5 mm vs.15.0 mm).The procedure was completed faster in the 16 Fr group compared to 12 Fr group(24.5 min vs.34.6 min).Stone clearance was highly successful in both groups(97.5%vs.95.0%).There was no difference in complications between the two groups.The decrease in hemoglobin was minimal in both groups(0.2 g/dL vs.0.3 g/dL).Conclusion:We found that the success rates were similar in both mini PCNL and the smaller ultra-mini PCNL groups.No significant difference in bleeding was noted in our pilot study,however,operative time was longer in the ultra-mini group as compared to the mini sheath group.

CT-based radiomics:predicting early outcomes after percutaneous transluminal renal angioplasty in patients with severe atherosclerotic renal artery stenosis

This study aimed to comprehensively evaluate non-contrast computed tomography(CT)-based radiomics for predicting early outcomes in patients with severe atherosclerotic renal artery stenosis(ARAS)after percutaneous transluminal renal angioplasty(PTRA).A total of 52 patients were retrospectively recruited,and their clinical characteristics and pretreatment CT images were collected.During a median follow-up period of 3.7 mo,18 patients were confirmed to have benefited from the treatment,defined as a 20%improvement from baseline in the estimated glomerular filtration rate.A deep learning network trained via self-supervised learning was used to enhance the imaging phenotype characteristics.Radiomics features,comprising 116 handcrafted features and 78 deep learning features,were extracted from the affected renal and perirenal adipose regions.More features from the latter were correlated with early outcomes,as determined by univariate analysis,and were visually represented in radiomics heatmaps and volcano plots.After using consensus clustering and the least absolute shrinkage and selection operator method for feature selection,five machine learning models were evaluated.Logistic regression yielded the highest leave-one-out cross-validation accuracy of 0.780(95%CI:0.660-0.880)for the renal signature,while the support vector machine achieved 0.865(95%CI:0.769-0.942)for the perirenal adipose signature.SHapley Additive exPlanations was used to visually interpret the prediction mechanism,and a histogram feature and a deep learning feature were identified as the most influential factors for the renal signature and perirenal adipose signature,respectively.Multivariate analysis revealed that both signatures served as independent predictive factors.When combined,they achieved an area under the receiver operating characteristic curve of 0.888(95%CI:0.784-0.992),indicating that the imaging phenotypes from both regions complemented each other.In conclusion,non-contrast CT-based radiomics can be leveraged to predict the early outcomes of PTRA,thereby assisting in identifying patients with ARAS suitable for this treatment,with perirenal adipose tissue providing added predictive value.

Dynamic changes of renal cortical blood perfusion before and after percutaneous transluminal renal artery stenting in patients with severe atherosclerotic renal artery stenosis

Background:This study aims to observe the dynamic changes of renal artery(RA)disease and cortical blood perfusion(CBP)evaluated by contrast-enhanced ultrasound(CEUS)after percutaneous transluminal renal artery stenting(PTRAS)in patients with severe atherosclerotic renal artery stenosis(ARAS)and to analyze the relationship between CBP and prognosis.Methods:This was a single-center retrospective cohort study.A total of 98 patients with unilateral severe ARAS after successful PTRAS in Beijing Hospital from September 2017 to September 2020 were included.According to renal glomerular filtration rate(GFR)detected by radionuclide imaging at 12 months after PTRAS,all patients were divided into the poor prognosis group(n=21,GFR decreased by≥20%compared with baseline)and the control group(n=77,GFR decreased by<20%or improved compared with baseline).Renal artery stenosis was diagnosed by digital subtraction angiography,and renal CBP was evaluated by CEUS using TomTec Imaging Systems(Germany)before PTRAS,at 6 months and 12 months after discharge.The receiver operating characteristic(ROC)curve with area under the curve(AUC)was used to analyze the predictive value of CBP parameters,including area under ascending curve(AUC1),area under the descending curve(AUC2),rising time(RT),time to peak intensity(TTP),maximum intensity(IMAX),and mean transit time(MTT)for poor prognosis.Results:Among the 98 patients,there were 52 males(53.1%),aged 55–74 years old,with an average age of 62.1±8.7 years,and an average artery stenosis of 82.3±12.9%.The poor prognosis group was associated with significantly increased incidence of diabetes(76.2%vs.41.6%),and lower levels of GFR of the stenotic kidney(21.8 mL/min vs.25.0 mL/min)and total GFR(57.6 mL/min vs.63.7 mL/min)(all P<0.05),compared with the control group(P<0.05).In addition,the rate of RA restenosis was significantly higher in the poor prognosis group than in the control group(9.5%vs.0,χ^(2)=9.462,P=0.002).Compared with the control group,the poor prognosis group was associated with significantly decreased baseline AUC1 and AUC2,and extended duration of TTP and MTT(P<0.05).At 6 months and 12 months of follow-up,patients in the control group were associated with markedly increased AUC1,AUC2,and IMAX,and shorter duration of RT and MTT(P<0.05).The ROC curve showed that the predictive values of AUC1,AUC2,RT,TTP,IMAX,and MTT for poor prognosis were 0.812(95%CI:0.698–0.945),0.752(95%CI:0.591–0.957),0.724(95%CI:0.569–0.961),0.720(95%CI:0.522–0.993),0.693(95%CI:0.507–0.947),and 0.786(95%CI:0.631–0.979),respectively.Conclusions:Preoperative renal CBP in severe ARAS patients with poor prognosis is significantly reduced,and does not show significant improvement after stent treatment over the first year of follow-up.The parameter AUC1 may be a good predictor for renal dysfunction after PTRAS in severe ARAS patients.Trial Registration:ChiCTR.org.cn,ChiCTR1800016252.