Deep-learning-based sampling position selection on color Doppler sonography images during renal artery ultrasound scanning.

Accurate selection of sampling positions is critical in renal artery ultrasound examinations, and the potential of utilizing deep learning (DL) for assisting in this selection has not been previously evaluated. This study aimed to evaluate the effectiveness of DL object detection technology applied to color Doppler sonography (CDS) images in assisting sampling position selection. A total of 2004 patients who underwent renal artery ultrasound examinations were included in the study. CDS images from these patients were categorized into four groups based on the scanning position: abdominal aorta (AO), normal renal artery (NRA), renal artery stenosis (RAS), and intrarenal interlobular artery (IRA). Seven object detection models, including three two-stage models (Faster R-CNN, Cascade R-CNN, and Double Head R-CNN) and four one-stage models (RetinaNet, YOLOv3, FoveaBox, and Deformable DETR), were trained to predict the sampling position, and their predictive accuracies were compared. The Double Head R-CNN model exhibited significantly higher average accuracies on both parameter optimization and validation datasets (89.3 ± 0.6% and 88.5 ± 0.3%, respectively) compared to other methods. On clinical validation data, the predictive accuracies of the Double Head R-CNN model for all four types of images were significantly higher than those of the other methods. The DL object detection model shows promise in assisting inexperienced physicians in improving the accuracy of sampling position selection during renal artery ultrasound examinations.

Fibromuscular dysplasia of the renal arteries: what do we know in 2024? / Dysplasie fibromusculaire des artères rénales : que savons-nous en 2024 ?

Fibromuscular dysplasia (FMD) is a rare nonatherosclerotic, noninflammatory vascular disease affecting mostly renal and carotid arteries and is the second most frequent cause of renal artery stenosis. The symptomatology is dominated by arterial hypertension due to the frequent involvement of the renal arteries and depends on the location of the lesions. Most of the cases are middle-aged women of Caucasian origin. There are two subtypes based on angiographic aspect: multifocal FMD (80% of the cases) and focal FMD (rarer with a more balanced sex ratio). Angioplasty of the renal arteries is generally disappointing with less than 50% cure of hypertension. It appears necessary to improve our knowledge of the FMD and to optimize the selection of eligible patients for revascularization with transdisciplinary collegial therapeutic decision.

La dysplasie fibromusculaire (DFM) est une maladie rare caractérisée par des sténoses segmentaires non artérioscléreuses, non inflammatoires, des artères de moyens calibres, touchant surtout les artères rénales et les carotides. Elle constitue la seconde cause de sténoses des artères rénales. La symptomatologie dépend de la localisation des lésions et est dominée par l'hypertension artérielle (HTA) en raison de l'atteinte fréquente des artères rénales. Cette pathologie touche majoritairement les femmes caucasiennes d'âge moyen. Il en existe deux sous-types, basés sur l'aspect angiographique : la DFM multifocale (80 % des cas) et la DFM focale (plus rare, sex ratio plus équilibré). Les résultats des prises en charge interventionnelles s'avèrent globalement décevants avec moins de 50 % de guérison de l'HTA. Il est nécessaire d'améliorer nos connaissances sur la physiopathologie de la DFM et d'optimiser la sélection des patients éligibles à une revascularisation par une prise de décision thérapeutique collégiale, en réunion de concertation pluridisciplinaire.

Effectiveness of contrast-enhanced duplex ultrasound for detecting renal artery stenosis: A systematic review.

PURPOSE: Contrast-enhanced duplex ultrasound (CEUS) might be a useful tool to diagnosing renal artery stenosis (RAS). We amalgamated and reviewed the evidence assessing the diagnostic accuracy of CEUS on detecting RAS compared to angiography. METHODS: This preregistered systematic review included studies that compared the presence of RAS via CEUS with angiography. Sources were searched in November 2022 and included Scopus, EMBASE, MEDLINE, CINAHL, and Academic Search Premier (n = 1717). The Quality Assessment of Diagnostic Studies 2 tool assessed study quality. Results are presented narratively. RESULTS: The studies included (n = 11) had a total of 447 unique participants (193 females) and average age of 56 ± 9 years. Five of eleven studies investigated CEUS using SonoVue contrast agent and reported an average accuracy (91% ± 2%), sensitivity (91% ± 3%), specificity (90% ± 5%), negative predictive value (86% ± 6%), and positive predictive value (94% ± 1%) with all values >80%. The accuracy of CEUS using other types of contrast agent (n = 6), including Levovsit (n = 3/6), Definity (n = 1/6), perfienapent emulsion (n = 1/6), and perfluorocarbon-exposed sonicated dextrose albumin (n = 1/6) was mixed. These studies detected an average accuracy of 91 ± 11% (n = 2/3% > 80%), sensitivity of 98% ± 4%, (n = 3/3% > 80%), and specificity of 86% ± 10% (n = 2/3% > 80%). Included studies had generally low risk of bias and applicability concerns except for unclear flow and timing (n = 7/11) and applicability of patient selection (n = 4/11). CONCLUSION: Despite being limited by the heterogeneity of included studies, our review indicates a high overall diagnostic accuracy for CEUS to detect RAS compared to angiography, with the largest evidence-base for SonoVue contrast. Radiologists and hospital decision makers should consider CEUS as an acceptable alternative to angiography.

3D printing: a useful tool for safe clinical practice in children with complex vasculature.

BACKGROUND: 3D printing has been used in different medical contexts, although it is underutilised in paediatrics. We present the first use of 3D printing in the management of three paediatric patients with complex renovascular disease. METHODS: Patient-specific 3D models were produced from conventional 2D imaging and manufactured using 3D polyjet printing technology. All three patients had different underlying pathologies, but all underwent multiple endovascular interventions (renal artery balloon angioplasty) prior to 3D printing and subsequent vascular surgery. The models were verified by an expert radiologist and then presented to the multidisciplinary team to aid with surgical planning. RESULTS: Following evaluation of the 3D-printed models, all patients underwent successful uni/bilateral renal auto-transplants and aortic bypass surgery. The 3D models allowed more detailed preoperative discussions and more focused planning of surgical approach, therefore enhancing safer surgical planning. It influenced clinical decision-making and shortened general anaesthetic time. The families and the patients reported that they had a significantly improved understanding of the patient's condition and had more confidence in understanding proposed surgical intervention, thereby contributing to obtaining good-quality informed consent. CONCLUSION: 3D printing has a great potential to improve both surgical safety and decision-making as well as patient understanding in the field of paediatrics and may be considered in wider surgical areas.

Double kiss mini-crush technique to treat complex recurrent renal artery in-stent restenosis.

The double-kiss mini-crush (DKMC) technique has been successfully deployed in the past for the treatment of complex coronary lesions even for left main lesions. Our case report consists of a proof-of-principle that the DKMC technique can be successfully translated as well to the field of complex renal artery lesions. Insightful thinking out-of-the "coronary" box in concert with skillful off-label application of coronary stenting procedures may open the gate for unprecedented opportunities for the treatment of difficult-to-tackle in-stent restenosis in the renal circulation.

Open bypass revascularisation for endovascular-resistant transplant renal artery stenosis secondary to mechanical renal artery kinking.

Transplant renal artery stenosis (TRAS) represents a significant vascular complication subsequent to renal transplantation. This pathology is associated with grave implications including graft dysfunction and mortality. Early identification and therapeutical intervention are imperative for preserving graft longevity and achieving optimal clinical outcomes. We detail the case of a male in his 20s, following renal transplantation, who encountered recurrent TRAS, aetiologically linked to mechanical arterial kinking. Initial management using endovascular techniques yielded insufficient resolution. Consequently, the persistence of endovascular-resistant stenosis necessitated a surgical bypass intervention using the great saphenous vein, granting a 2-year period devoid of restenosis. The existing literature emphasises the indispensability of discerning the appropriate juncture for transitioning from endovascular to surgical management in TRAS cases. The robustness and durability of bypass grafts present an efficacious therapeutical strategy in contemporaneous practice.

Unusual Renal Uptake of 131 I-MIBG in a Young Hypertensive With Renal Artery Stenosis.

ABSTRACT: A 10-year-old hypertensive girl underwent 131 I-MIBG scan to rule out neural crest derived tumor. The whole-body images revealed diffuse intense tracer uptake in the right kidney, which persisted in 96-hour images as well. CT renal angiography revealed 90% to 95% right renal artery stenosis. Thereafter, she underwent baseline and angiotensin receptor blockade renal dynamic imaging, which revealed hemodynamically significant renal artery stenosis. Pattern of diffuse and intense 131 I-MIBG uptake, albeit rare, still warrants further evaluation to rule out renal artery stenosis and investigate its hemodynamic significance for appropriate management.

Deep-learning-based renal artery stenosis diagnosis via multimodal fusion.

PURPOSE: Diagnosing Renal artery stenosis (RAS) presents challenges. This research aimed to develop a deep learning model for the computer-aided diagnosis of RAS, utilizing multimodal fusion technology based on ultrasound scanning images, spectral waveforms, and clinical information. METHODS: A total of 1485 patients received renal artery ultrasonography from Peking Union Medical College Hospital were included and their color doppler sonography (CDS) images were classified according to anatomical site and left-right orientation. The RAS diagnosis was modeled as a process involving feature extraction and multimodal fusion. Three deep learning (DL) models (ResNeSt, ResNet, and XCiT) were trained on a multimodal dataset consisted of CDS images, spectrum waveform images, and individual basic information. Predicted performance of different models were compared with senior physician and evaluated on a test dataset (N = 117 patients) with renal artery angiography results. RESULTS: Sample sizes of training and validation datasets were 3292 and 169 respectively. On test data (N = 676 samples), predicted accuracies of three DL models were more than 80% and the ResNeSt achieved the accuracy 83.49% ± 0.45%, precision 81.89% ± 3.00%, and recall 76.97% ± 3.7%. There was no significant difference between the accuracy of ResNeSt and ResNet (82.84% ± 1.52%), and the ResNeSt was higher than the XCiT (80.71% ± 2.23%, p < 0.05). Compared to the gold standard, renal artery angiography, the accuracy of ResNest model was 78.25% ± 1.62%, which was inferior to the senior physician (90.09%). Besides, compared to the multimodal fusion model, the performance of single-modal model on spectrum waveform images was relatively lower. CONCLUSION: The DL multimodal fusion model shows promising results in assisting RAS diagnosis.

Patterns of cortical oxygenation may predict the response to stenting in subjects with renal artery stenosis: A radiomics-based model.

BACKGROUND: Percutaneous-transluminal renal angioplasty (PTRA) and stenting aim to halt the progression of kidney disease in patients with renal artery stenosis (RAS), but its outcome is often suboptimal. We hypothesized that a model incorporating markers of renal function and oxygenation extracted using radiomics analysis of blood oxygenation-level dependent (BOLD)-MRI images may predict renal response to PTRA in swine RAS. MATERIALS AND METHODS: Twenty domestic pigs with RAS were scanned with CT and BOLD MRI before and 4 weeks after PTRA. Stenotic (STK) and contralateral (CLK) kidney volume, blood flow (RBF), and glomerular filtration rate (GFR) were determined, and BOLD-MRI R2 * maps were generated before and after administration of furosemide, a tubular reabsorption inhibitor. Radiomics features were extracted from pre-PTRA BOLD maps and Robust features were determined by Intraclass correlation coefficients (ICC). Prognostic models were developed to predict post-PTRA renal function based on the baseline functional and BOLD-radiomics features, using Lasso-regression for training, and testing with resampling. RESULTS: Twenty-six radiomics features passed the robustness test. STK oxygenation distribution pattern did not respond to furosemide, whereas in the CLK radiomics features sensitive to oxygenation heterogeneity declined. Radiomics-based model predictions of post-PTRA GFR (r = 0.58, p = 0.007) and RBF (r = 0.68; p = 0.001) correlated with actual measurements with sensitivity and specificity of 92% and 67%, respectively. Models were unsuccessful in predicting post-PTRA systemic measures of renal function. CONCLUSIONS: Several radiomics features are sensitive to cortical oxygenation patterns and permit estimation of post-PTRA renal function, thereby distinguishing subjects likely to respond to PTRA and stenting.

Assessment of Angiography-Based Renal Quantitative Flow Ratio Measurement in Patients with Atherosclerotic Renal Artery Stenosis.

Background: Quantitative flow ratio (QFR) is an angiography-based fractional flow reserve measurement without pressure wire or induction of hyperemia. A recent innovation that uses combined geometrical data and hemodynamic boundary conditions to measure QFR from a single angiographic view has shown the potential to measure QFR of the renal artery-renal QFR (rQFR). Objective: The aim of this pilot study was to assess the feasibility of rQFR measurement and the contribution of rQFR in selecting patients with atherosclerotic renal artery stenosis (ARAS) undergoing revascularization. Methods: This retrospective trial enrolled patients who had ARAS (50-90%) and hypertension. The enrolled patients were treated by optimal antihypertensive medication or revascularization, respectively, and the therapeutic strategies were based on rFFR measurement and/or clinical feature. Results: A total of 55 patients underwent rQFR measurement. Among the enrolled patients, 18 underwent optimal antihypertensive medication and 37 underwent revascularization, 19 patients in whom rQFR and rFFR were both assessed. During the 180-day follow-up, 25 patients saw an improvement in their blood pressure among the 37 patients that underwent revascularization. ROC analysis revealed that rQFR had a high diagnostic accuracy for predicting blood pressure improvement (AUCrQFR = 0.932, 95% CI 0.798-0.998). The ideal cut-off value of rQFR for predicting blood pressure improvement after revascularization is ≤0.72 (sensitivity: 72.00%, specificity: 100%). The paired t test and Bland-Altman analyses demonstrated good agreement between rQFR and rFFR (t = 1.887, 95% CI -0.021 to 0.001, 95% limits of agreement: -0.035 to 0.055, p = 0.075). The Spearman correlation test reveals that there was a significant positive correlation between rQFR and rFFR (r = 0.952, 95% CI 0.874 to 0.982, p < 0.001). Conclusion: The rQFR has the potential to enhance the ability of angiography to detect functionally significant renal artery stenosis during angiography and to produce results that are comparable to invasive hemodynamic assessment.

A Rare Case of Focal Renal Fibromuscular Dysplasia Treated With Angioplasty: A Case Report.

BACKGROUND: Fibromuscular dysplasia is an idiopathic, segmental, nonatherosclerotic, noninflammatory vascular disease that can lead to arterial stenosis, tortuosity, occlusion, aneurysms, and dissection. Fibromuscular dysplasia is a rare cause of hypertension that can easily be missed. To date, there has been no definitive treatment for fibromuscular dysplasia. CASE REPORT: In this report, we present an uncommon case of renovascular hypertension in a 21-year-old non-white female with a 3-year history of hypertension secondary to fibromuscular dysplasia involving bilateral renal arteries. Computed tomography angiography during the arterial phase revealed distal focal narrowing of the right main renal artery, distal focal narrowing of the left main renal artery, and proximal focal narrowing of the left accessory lower renal artery. Percutaneous balloon dilatation of the stenotic lesion was performed successfully up to 1 year After the procedure, the arterial blood pressure was within the normal range (110/70 to 125/75 mmHg) without medication. After 1 year of follow-up, CTA revealed re-stenosis in left main renal artery without clinical symptoms and normal blood pressure. Repeated procedure was done successfully. CONCLUSIONS: This case report highlights the difficulty in the diagnosis and treatment of focal fibromuscular dysplasia in young non-white female patients. Computerized tomographic angiography is a useful tool for identifying the cause and showing the benefit of percutaneous transluminal renal angioplasty treatment for this rare entity, as an early percutaneous angioplasty intervention may have a clinical cure for hypertension.

Transplant renal artery stenosis: Study of incidence using doppler ultrasound, risk factors and analysis is effect in graft outcomes.

INTRODUCTION AND OBJECTIVES: Transplant renal artery stenosis (TRAS) is a vascular complication after kidney transplantation which estimated incidence is 13%. It could cause refractory arterial hypertension, kidney dysfunction and premature death in transplant recipients. METHODS: We carried out a retrospective study including every patient who underwent renal transplantation between 2014 and 2020. They were evaluated with a systematic post-transplant renal Doppler ultrasound. To identify independent risk factors for transplant renal artery stenosis we performed a multivariate analysis. RESULTS: Seven hundred twenty-four kidney transplants were included, 12% ​​were living donors and 88% were deceased donors. The mean age was 54.8 in recipients and 53 in donors. Transplant renal artery stenosis was diagnosed in 70 (10%) recipients, the majority in the first 6 months after surgery. 51% of patients with transplant renal artery stenosis were managed conservatively. The multivariate analysis showed diabetes mellitus, graft rejection, arterial resuture and donor body mass index as independent risk factors for transplant renal artery stenosis. Survival of the grafts with transplant renal artery stenosis was 98% at 6 months and 95% at two years. CONCLUSIONS: The systematic performance of Doppler ultrasound in the immediate post-transplant period diagnosed 10% of transplant renal artery stenosis in our cohort. Despite the above risk factors, an adequate monitoring and treatment could avoid the increased risk of graft loss in patients with transplant renal artery stenosis.

Endovascular treatment of renal artery stenosis in Germany: a retrospective analysis of the DEGIR registry 2018-2021.

PURPOSE: To provide an overview of endovascular treatment of renal artery stenosis (RAS) using the data of the Deutsche Gesellschaft für interventionelle Radiologie (DeGIR) quality management system. MATERIALS AND METHODS: A retrospective analysis was performed. Pre-, peri- and postprocedural data, technical success rates, complication rates, and clinical success rates at dismissal were examined. RESULTS: Between 2018 and 2021, 2134 angiography examinations of the renal arteries were performed: diagnostic angiography in 70 patients (3 %), balloon angioplasty in 795 (37 %), stent implantation in 1166 (55 %) and miscellaneous procedures in 103 (5 %). The lesion length was less than or equal to 5 mm in 1837 patients (87 %), between 5 and 10 mm in 197 (9 %), and between 10 and 20 mm in 62 (3 %). The degree of stenosis was less than 50 % in 156 patients (7 %), greater than 50 % in 239 (11 %), and greater than 70 % in 1472 (70 %). Occlusion was treated in 235 patients (11 %). Symptoms at discharge resolved in 600 patients (29 %), improved in 1012 (49 %), were unchanged in 77 (4 %), and worsened in 5 (0.2 %). Complications were reported in 51 patients (2.5 %) and the mortality rate was 0.15 %. CONCLUSION: A substantial number of patients with RAS and occlusions were treated by radiologists in Germany, with high technical success rates and low complication rates. The indication should be determined carefully as the current European guidelines for the treatment of RAS suggest that only carefully selected groups of patients will benefit from recanalizing treatment. KEY POINTS: · Carefully selected patient groups may benefit from endovascular treatment of renal artery stenosis.. · Analysis of the DEGIR quality management database shows that treatment of renal artery stenosis was performed by radiologists in Germany with high technical success rates and low complication rates.. · Recanalization even led to symptom improvement in a large proportion of patients with occlusions..

Risks and benefits of renal artery stenting in fibromuscular dysplasia: Lessons from the ARCADIA-POL study.

INTRODUCTION: Although renal stenting is the standard revascularization method for atherosclerotic renal artery stenosis (RAS) (FMD-RAS), stenting in fibromuscular dysplasia (FMD) RAS is usually limited to periprocedural complications of angioplasty and primary arterial dissection. The main aim of the study was to retrospectively analyze the immediate and long-term results of renal stenting versus angioplasty in patients with FMD. METHODS: Of 343 patients in the ARCADIA-POL registry, 58 patients underwent percutaneous treatment due to FMD-RAS (in 70 arteries). Percutaneous transluminal renal angioplasty (PTRA) was performed as an initial treatment in 61 arteries (PTRA-group), whereas primary stenting was undertaken in nine arteries (stent-group). Stent-related complications were defined as: in-stent restenosis > 50% (ISR); stent fracture; under-expansion; or migration. RESULTS: In the PTRA-group, the initial restenosis rate was 50.8%. A second procedure was then performed in 22 arteries: re-PTRA (12 arteries) or stenting (10 arteries). The incidence of recurrent restenosis after re-PTRA was 41.7%. Complications occurred in seven of 10 (70%) arteries secondarily treated by stenting: two with under-expansion and five with ISR. In the stent-group, stent under-expansion occurred in one case (11.1%) and ISR in three of nine stents (33.3%). In combined analysis of stented arteries, either primarily or secondarily, stent-related complications occurred in 11/19 stenting procedures (57.9%): three due to under-expansion and eight due to ISRs. Finally, despite several revascularization attempts, four of 19 (21%) stented arteries were totally occluded and one was significantly stenosed at follow-up imaging. CONCLUSION: Our study indicates that renal stenting in FMD-RAS may carry a high risk of late complications, including stent occlusion. Further observational data from large-scale registries are required.

Clinical Practice Report of Contrast-Enhanced Ultrasound in Renal Artery Disease.

OBJECTIVES: To evaluate the diagnostic performance of renal artery contrast-enhanced ultrasound (CEUS) with modified inspection section and summarize subsequent changes in imaging assessment of renal artery disease. METHODS: A total of 1015 patients underwent renal artery CEUS were included in the study. Among them, 79 patients (156 renal arteries) suspected with renal artery stenosis (RAS) underwent digital subtraction angiography (DSA) subsequently. DSA was used as the gold standard to evaluate the diagnostic performance of CEUS in detecting RAS (≥30%) and severe stenosis (≥70%), as well as the diagnostic accuracy of classification of stenosis degree. Besides, 127 of the 1015 patients underwent other imaging examinations such as computed tomography angiography (CTA) or magnetic resonance angiography (MRA) after CEUS and annual proportion of these imaging examinations was assessed. RESULTS: The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of CEUS for detecting RAS (≥30%) was 96.4%, 88.6%, 94.2%, 95.6% and 90.7%, respectively and the kappa value was .857 (P < .01). CEUS had a good performance in distinguishing severe stenosis (≥70%) with a sensitivity of 91.1%, specificity of 95.5%, accuracy of 92.9%, PPV of 96.5%, NPV of 88.7% and the kappa value was 0.857(P < .01). There was no significant difference between CEUS and DSA in detecting stenosis (P = 1.0) and severe stenosis (P = .227). The diagnostic accuracy of CEUS in grading RAS was 85.3% and the kappa value was 0.753 (P < .01). Besides, the annual proportion of other imaging examinations decreased for 4 consecutive years. CONCLUSIONS: CEUS is a non-invasive, safe and valuable technique for the assessment of renal artery disease and worthy of promotion.

A rare cause and an even rarer treatment of hypertension in a 5-year-old boy: Mid-aortic syndrome.

Renal artery stenosis is one of the common vascular diseases that cause hypertension in children. However, renal artery aneurysms and abdominal aortic aneurysms, which may be components of mid-aortic syndrome, are rarely associated with renal artery stenosis. Despite its rarity, early diagnosis and treatment are critical to prevent fatal complications. Currently, non-surgical invasive techniques are considered the first choice for treatment, but in some cases, surgery is inevitable. Here, we present a 5-year-old boy with a mid-aortic syndrome. The patient presented with a history of severe headache and epistaxis 5-6 times a day and was diagnosed with hypertension. A 9 × 9 mm saccular aneurysm on the anterior surface of the abdominal aorta at the level of the left renal artery ostium, and a 12 mm aneurysm in the left renal artery after a stenotic segment at the hilum level was detected in the doppler USG and contrast-enhanced imaging techniques. The patient was operated on electively. We used a PTFE patch to repair the abdominal aorta and, saphenous vein which was taken from his father to repair the renal artery. The patient recovered well and was discharged on the 18th day.

Assessment of Transplant Renal Artery Stenosis with Non-contrast-Enhanced Magnetic Resonance Angiography: Comparison with Digital Subtraction Angiography.

RATIONALE AND OBJECTIVES: Early diagnosis of transplant renal artery stenosis (TRAS) is crucial for salvaging kidney function and improving patient prognosis. The purpose of this study was to evaluate image quality of non-contrast-enhanced MR angiography (NCE-MRA) and the value of NCE-MRA in evaluating TRAS compared to DSA. MATERIALS AND METHODS: In 60 patients with TRAS confirmed by DSA, the degree of TRAS was assessed using balanced triggered angiography non-contrast-enhanced (B-TRANCE) MR angiography and was compared to that of DSA. Image quality for NCE-MRA was assessed independently by two radiologists. The Wilcoxon signed-rank test was used to compare NCE-MRA with DSA in assessing TRAS degree. Specificity, sensitivity, accuracy, positive-predictive value (PPV), and negative-predictive value (NPV) of NCE-MRA for the detection of marked (≥50%) TRAS were calculated. RESULTS: The image quality of NCE-MRA based on the B-TRANCE technology of transplanted renal arteries was sufficient (excellent in 81.67%, good in 8.33%, moderate in 6.67%, and non-diagnostic in 3.33%) and had a high inter-observer reproducibility (Kappa=0.836). DSA helped identify severe, moderate, and mild stenosis in 6, 32, and 22 arteries, respectively. No significant difference in the extent of TRAS between NCE-MRA and DSA were observed (P = 0.317). The specificity, sensitivity, accuracy, PPV, and NPV of NCE-MRA in detecting marked (≥50%) TRAS were 90.91%, 100%, 96.55%, 94.74%, and 100%, respectively. CONCLUSION: NCE-MRA based on B-TRANCE technology has shown promising consistency with DSA in evaluating TRAS and yielding high sensitivity, specificity, and accuracy in assessing the severity of TRAS.

Renal artery stenosis stenting with unmasking and embolisation of a renal arteriovenous fistula.

A man in his 70s was presented to the emergency department with uncontrollable hypertension and worsening renal function on a background of atherosclerosis-related bilateral renal artery stenosis. Following progressive deterioration in renal function and refractory hypertension, the patient was referred to interventional radiology for consideration of renal artery stenting. Following stenting of the right renal artery, a large renal arteriovenous fistula became apparent, which required emergent embolisation. Both procedures were successful, with excellent clinical and radiological responses.

Drug-coated balloon for treatment of non-atherosclerotic renal artery stenosis-a multi-center study.

INTRODUCTION: Renal artery stenosis (RAS) is a significant reason for secondary hypertension. Impaired renal function and subsequent cardiopulmonary dysfunction could also occur. Patients of non-atherosclerotic RAS has a relatively young age and long life expectancy. Revascularization with percutaneous transluminal angioplasty (PTA) is a viable treatment option. However, restenosis is unavoidable which limits its use. Drug-coated balloon (DCB) has been proven to be effective in restenosis prevention in femoropopliteal arterial diseases and in patients with renal artery stenosis. And PTA for Renal artery fibromuscular dysplasia is safe and clinically successful. Therefore, we could speculate that DCB might have potential efficacy in non-atherosclerotic RAS treatment. METHODS AND ANALYSIS: This will be a randomized multi-center-controlled trial. Eighty-four eligible participants will be assigned randomly in a 1:1 ratio to the control group (plain old balloon, POB) and the experimental group (DCB). Subjects in the former group will receive balloon dilatation alone, and in the latter group will undergo the DCB angioplasty. The DCB used in this study will be a paclitaxel-coated balloon (Orchid, Acotec Scientific Holdings Limited, Beijing, China). Follow-up visits will be scheduled 1, 3, 6, 9, and 12 months after the intervention. Primary outcomes will include controlled blood pressure and primary patency in the 9-month follow-up. Secondary outcomes will include technical success rate, complication rate, and bail-out stenting rate. TRIAL REGISTRATION: ClinicalTrials.gov (number NCT05858190). Protocol version V.4 (3 May 2023).