When Revascularization May Be Appropriate in Atherosclerotic Renal Artery Stenosis.

Renal artery stenosis (RAS) is a condition that involves the narrowing of one or both renal arteries, most commonly caused by either atherosclerosis or fibroplasia. RAS can present in a multitude of clinical manifestations involving hypertension (HTN), heart failure, and renal failure. Current recommendations for treating patients with RAS involve strict medical therapy often without invasive therapies. However, in more complicated patients with RAS, recent clinical studies and guidelines have offered varying recommendations, which has presented challenges in managing these cases. This review aims to summarize current evidence to best evaluate which patients with RAS may benefit from renal artery revascularization as opposed to medical therapy alone.

Human liver derived mesenchymal stromal cells ameliorate murine ischemia-induced inflammation through macrophage polarization.

Introduction: The immunomodulatory properties of mesenchymal stromal cells (MSC) have been well-characterized in in-vitro and in-vivo models. We have previously shown that liver MSC (L-MSC) are superior inhibitors of T-cell activation/proliferation, NK cell cytolytic function, and macrophage activation compared to adipose (A-MSC) and bone marrow MSC (BM-MSC) in-vitro. Method: To test these observations in-vivo, we infused these types of MSC into mice with unilateral renal artery stenosis (RAS), an established model of kidney inflammation. Unilateral RAS was induced via laparotomy in 11-week-old, male 129-S1 mice under general anesthesia. Control mice had sham operations. Human L-MSC, AMSC, and BM-MSC (5x105 cells each) or PBS vehicle were injected intra-arterially 2 weeks after surgery. Kidney morphology was studied 2 weeks after infusion using micro-MRI imaging. Renal inflammation, apoptosis, fibrosis, and MSC retention were studied ex-vivo utilizing western blot, immunofluorescence, and immunohistological analyses. Results: The stenotic kidney volume was smaller in all RAS mice, confirming significant injury, and was improved by infusion of all MSC types. All MSC-infused groups had lower levels of plasma renin and proteinuria compared to untreated RAS. Serum creatinine improved in micetreated with BM- and L-MSC. All types of MSC located to and were retained within the stenotic kidneys, but L-MSC retention was significantly higher than A- and BM-MSC. While all groups of MSC-treated mice displayed reduced overall inflammation and macrophage counts, L-MSC showed superior potency in-vivo at localizing to the site of inflammation and inducing M2 (reparative) macrophage polarization to reduce inflammatory changes. Discussion: These in-vivo findings extend our in-vitro studies and suggest that L-MSC possess unique anti-inflammatory properties that may play a role in liver-induced tolerance and lend further support to their use as therapeutic agents for diseases with underlying inflammatory pathophysiology.

Takayasu arteritis manifesting as acute kidney injury and congestion due to renal artery stenosis and myocarditis: a case report.

Background: Takayasu arteritis is a large-vessel vasculitis that affects the aorta and its primary branches. Myocarditis is a rare life-threatening complication and potential diagnostic pitfall in patients with Takayasu arteritis. Case summary: A previously healthy 18-year-old woman presenting with fever, back pain, and dyspnoea was admitted to another hospital for acute hypertension (blood pressure, 230/106 mmHg) and congestive heart failure. Intravenous methylprednisolone pulse with antihypertensive and diuretic medications slightly improved her congestion. However, she developed acute kidney injury and was transferred to our hospital. Transthoracic echocardiography indicated a left ventricular ejection fraction of 45% and diffuse left ventricular hypokinesis. Doppler ultrasound test and magnetic resonance angiography revealed severe bilateral renal artery stenosis. Her diagnosis was Takayasu arteritis, and she received high-dose glucocorticoids. She required temporary haemodialysis, but 2 months after admission, her serum creatinine improved to 1.1 mg/dL without surgical or cardiovascular interventions. Although the pre-discharge test with 1.5 T cardiac magnetic resonance initially failed to diagnose myocarditis, 3 T cardiac magnetic resonance imaging revealed increased native T1 values on T1 mapping (1283-1393 ms), moderate pericardial effusion, and systolic left ventricular wall motion abnormality, indicating active myocarditis. During 6-month subcutaneous tocilizumab treatment (162 mg/week), a left ventricular ejection fraction improved to 55-60% without a relapse. Discussion: This case report highlights the benefits of early multimodal imaging tests including cardiac magnetic resonance imaging for myocarditis and renal artery involvement in Takayasu arteritis. Tocilizumab might be an efficient therapeutic option for severe acute manifestations including myocarditis in young women of reproductive age.

Evaluation and Management of Resistant Hypertension: Core Curriculum 2024.

Resistant hypertension is defined as blood pressure above goal despite confirmed adherence to 3 first-line antihypertensive agents or when blood pressure is controlled with 4 or more medications at maximal or maximally tolerated doses. In addition to meeting these criteria, identifying patients with true resistant hypertension requires both accurate in-office blood pressure measurement as well as excluding white coat effects through out-of-office blood pressure measurements. Patients with resistant hypertension are at higher risk for adverse cardiovascular events and are more likely to have a potentially treatable secondary cause contributing to their hypertension. Effective treatment of resistant hypertension includes ongoing lifestyle modifications and collaboration with patients to detect and address barriers to optimal medication adherence. Pharmacologic treatment should prioritize optimizing first-line, once daily, longer acting medications followed by the stepwise addition of second-, third-, and fourth-line agents as tolerated. Physicians should systematically evaluate for and address any underlying secondary causes. A coordinated, multidisciplinary team approach including clinicians with experience in treating resistant hypertension is essential. New treatment options, including both pharmacologic and device-based therapies, have recently been approved, and more are in the pipeline; their optimal role in the management of resistant hypertension is an area of ongoing research.

Graft survival after percutaneous transluminal renal stenting for transplant renal artery stenosis (TRAS) is worse compared to matched cadaveric grafts without TRAS.

OBJECTIVES: Transplant renal artery stenosis (TRAS) is now recognized as a curable disease with a good prognosis if intervention occurs in the early stage. However, the mid-term outcomes of TRAS when treated by percutaneous transluminal angioplasty with stent placement have yet to be fully elucidated. The purpose of this study was to compare mid-term graft and patient survival of TRAS group with a control group. PATIENTS AND METHODS: Ninety-two patients were diagnosed of TRAS between January 2016 and January 2022 in our center. Fifty-six pairs of recipients with grafts from the same donor were selected as a study group with TRAS and a control group without TRAS, respectively. All donor kidneys were from deceased organ donation rather than living donors. The primary endpoints were graft and patient survival. The secondary outcomes were changes in renal graft function. RESULTS: The mean follow-up time for the TRAS group was 43.6 months, while the mean follow-up time for the control group was 45.3 months. In the TRAS group, the age of patients ranged from 11 to 62 years with 39 males and 17 females. In the control group, the age of patients ranged from 18 to 67 years with 40 males and 16 females. In the TRAS group, there were more patients with diabetic nephropathy as the primary renal disease compared to the control group (5/56 vs 0/56), and the incidence of acute rejection was higher in the TRAS group than in the control group (12/56 vs 3/56). Eight patients in the TRAS group and one patient in the control group experienced graft loss (p = .019). Four patients in the TRAS group and four patients in the control group died with functional renal allograft during the follow-up time (p = .989). The levels of eGFR did not differ significantly between the two groups in the first three years after kidney transplant (p > .05). Patients in the TRAS group had worse graft functionality (eGFR, 44.96 ± 18.9 vs 54.9 ± 19.6 mL/min) in the fourth year when compared with the control group (p = .01). CONCLUSIONS: The graft function deteriorated faster, and graft survival was lower in the TRAS group treated by stent placement when compared with a control group without TRAS over the mid-term.

Assessment of renal transplant dysfunction by doppler sonography: A systematic review and meta-analysis.

Background: Doppler sonography parameters, particularly the resistive index (RI), have been identified as an essential tool for assessing renal transplant dysfunction (RTD). However, there is some ambiguity in the findings of previous research studies on this matter. Therefore, the objective of our study is to examine the relationship between changes in RI subsequent to RTD. Methods: This was a systematic review and meta-analysis study. We searched three electronic databases PubMed, Web of Science, and Scopus, from the year 2000 to 10 May 2022. The main effect size was considered as the mean RI differences of cases with RTD confirmed by biopsy with control patients with no RTD. We used random effect models to pool the effect size. Results: Thirteen studies were included in our review. The pooled mean (95% CI) for the control group was calculated to be 0.71 (0.67, 0.75) and for patients with renal transplant dysfunction was 0.73 (0.68, 0.78), under a random effect model with high heterogeneity for both analyses (I2=98% and 97%, respectively). The pooled mean was significantly different between the control group and patients with RTD (P= 0.05), based on a t-test of pooled effect sizes. Conclusions: Based on the result of our study, we showed that there is a significant difference between RI in patients with kidney transplant dysfunction and the control group. However, RI cannot substitute kidney biopsy in the management and diagnosis of RTD.

Intracerebral Hemorrhage in a Child with Renal Artery Stenosis and COVID-19.

Pediatric intracerebral hemorrhage is a rare condition among children. We discuss the case of a 7-year-old Filipino male with generalized tonic seizures and diagnosed to have both SARS-CoV-2 infection and hypertension secondary to renal arterial stenosis. The occurrence of intracerebral hemorrhage in children, though commonly caused by arteriovenous malformations, may be secondary to an acute hypertensive episode. In this case, the presence of COVID-19 in the patient may have been contributory to the development of spontaneous intracerebral hemorrhage due to its direct endothelial effects, as well as its dysregulatory action on the renin-angiotensin-aldosterone system.

Cerebral arteriopathies of childhood and stroke - A focus on systemic arteriopathies and pediatric fibromuscular dysplasia (FMD).

Systemic vascular involvement in children with cerebral arteriopathies is increasingly recognized and often highly morbid. Fibromuscular dysplasia (FMD) represents a cerebral arteriopathy with systemic involvement, commonly affecting the renal and carotid arteries. In adults, FMD diagnosis and classification typically relies on angiographic features, like the 'string-of-beads' appearance, following exclusion of other diseases. Pediatric FMD (pFMD) is considered equivalent to adult FMD although robust evidence for similarities is lacking. We conducted a comprehensive literature review on pFMD and revealed inherent differences between pediatric and adult-onset FMD across various domains including epidemiology, natural history, histopathophysiology, clinical, and radiological features. Although focal arterial lesions are often described in children with FMD, the radiological appearance of 'string-of-beads' is highly nonspecific in children. Furthermore, children predominantly exhibit intimal-type fibroplasia, common in other childhood monogenic arteriopathies. Our findings lend support to the notion that pFMD broadly reflects an undefined heterogenous group of monogenic systemic medium-or-large vessel steno-occlusive arteriopathies rather than a single entity. Recognizing the challenges in categorizing complex morphologies of cerebral arteriopathy using current classifications, we propose a novel term for describing children with cerebral and systemic vascular involvement: 'cerebral and systemic arteriopathy of childhood' (CSA-c). This term aims to streamline patient categorization and, when coupled with advanced vascular imaging and high-throughput genomics, will enhance our comprehension of etiology, and accelerate mechanism-targeted therapeutic developments. Lastly, in light of the high morbidity in children with cerebral and systemic arteriopathies, we suggest that investigating for systemic vascular involvement is important in children with cerebral arteriopathies.

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.

A Non-Coronary, Peripheral Arterial Atherosclerotic Disease (Carotid, Renal, Lower Limb) in Elderly Patients-A Review: Part I-Epidemiology, Risk Factors, and Atherosclerosis-Related Diversities in Elderly Patients.

Atherosclerosis is a generalized and progressive disease. Ageing is a key risk factor for atherosclerosis progression that is associated with the increased incidence of ischemic events in supplied organs, including stroke, coronary events, limb ischemia, or renal failure. Cardiovascular disease is the leading cause of death and major disability in adults ≥ 75 years of age. Atherosclerotic occlusive disease affects everyday activity and quality of life, and it is associated with reduced life expectancy. Although there is evidence on coronary artery disease management in the elderly, there is insufficient data on the management in older patients presented with atherosclerotic lesions outside the coronary territory. Despite this, trials and observational studies systematically exclude older patients, particularly those with severe comorbidities, physical or cognitive dysfunctions, frailty, or residence in a nursing home. This results in serious critical gaps in knowledge and a lack of guidance on the appropriate medical treatment and referral for endovascular or surgical interventions. Therefore, we attempted to gather data on the prevalence, risk factors, and management strategies in patients with extra-coronary atherosclerotic lesions.

A Non-Coronary, Peripheral Arterial Atherosclerotic Disease (Carotid, Renal, Lower Limb) in Elderly Patients-A Review PART II-Pharmacological Approach for Management of Elderly Patients with Peripheral Atherosclerotic Lesions outside Coronary Territory.

BACKGROUND: Aging is a key risk factor for atherosclerosis progression that is associated with increased incidence of ischemic events in supplied organs, including stroke, coronary events, limb ischemia, or renal failure. Cardiovascular disease is the leading cause of death and major disability in adults ≥ 75 years of age. Atherosclerotic occlusive disease affects everyday activity, quality of life, and it is associated with reduced life expectancy. As most multicenter randomized trials exclude elderly and very elderly patients, particularly those with severe comorbidities, physical or cognitive dysfunctions, frailty, or residence in a nursing home, there is insufficient data on the management of older patients presenting with atherosclerotic lesions outside coronary territory. This results in serious critical gaps in knowledge and a lack of guidance on the appropriate medical treatment. In addition, due to a variety of severe comorbidities in the elderly, the average daily number of pills taken by octogenarians exceeds nine. Polypharmacy frequently results in drug therapy problems related to interactions, drug toxicity, falls with injury, delirium, and non-adherence. Therefore, we have attempted to gather data on the medical treatment in patients with extra-cardiac atherosclerotic lesions indicating where there is some evidence of the management in elderly patients and where there are gaps in evidence-based medicine. Public PubMed databases were searched to review existing evidence on the effectiveness of lipid-lowering, antithrombotic, and new glucose-lowering medications in patients with extra-cardiac atherosclerotic occlusive disease.

Doppler Ultrasound of the Renal Vasculature.

Ultrasound is the first-line imaging modality used in patients with suspected renovascular disease. Common indications include renovascular hypertension and unexplained renal dysfunction. We review the ultrasound imaging findings of various pathologies involving the renal vessels, including the renal arteries (atherosclerotic stenosis, fibromuscular dysplasia, dissection, arteriovenous fistula, and aneurysm) and veins (tumor and bland thrombus as well as vascular compression syndromes). The current role of renal artery stent placement for atherosclerotic stenosis is also discussed.

Improving outcomes in atherosclerotic renovascular disease: importance of clinical presentation and multi-disciplinary review.

BACKGROUND AND OBJECTIVES: Atherosclerotic renal artery stenosis may cause hypertension, chronic kidney disease and heart failure, but large randomized control trials to date have shown no major additional benefit of renal revascularization over optimal medical management. However, these trials did not consider outcomes specifically in relation to clinical presentations. Given that atherosclerotic renal artery stenosis is a heterogenous condition, measures of success likely differ according to the clinical presentation. Our retrospective study objectives were to determine the effects of revascularization when applied to specific clinical presentations and after careful multi-disciplinary team review. METHODS: All patients presenting to our centre and its referring hospitals with radiological findings of at least one renal artery stenosis > 50% between January 2015 and January 2020 were reviewed at the renovascular multi-disciplinary team meeting with revascularization considered in accordance with international guidelines, notably for patients with anatomically significant renal artery stenosis, adequately sized kidney and presentations with any of; deteriorating kidney function, heart failure syndrome, or uncontrollable hypertension. Optimal medical management was recommended for all patients which included lipid lowering agents, anti-platelets and anti-hypertensives targeting blood pressure ≤ 130/80 mmHg. The effect of revascularization was assessed according to the clinical presentation; blood pressure and number of agents in those with renovascular hypertension, delta glomerular filtration rate in those with ischaemic nephropathy and heart failure re-admissions in those with heart failure syndromes. RESULTS: During this 5-year period, 127 patients with stenosis ≥ 50% were considered by the multidisciplinary team, with 57 undergoing revascularization (17 primarily for severe hypertension, 25 deteriorating kidney function, 6 heart failure syndrome and 9 for very severe anatomical stenosis). Seventy-nine percent of all revascularized patients had a positive outcome specific to their clinical presentation, with 82% of those with severe hypertension improving blood pressure control, 72% with progressive ischaemic nephropathy having attenuated GFR decline, and no further heart failure admissions in those with heart failure. Seventy-eight percent of patients revascularized for high grade stenosis alone had better blood pressure control with 55% also manifesting renal functional benefits. CONCLUSIONS: Multi-disciplinary team discussion successfully identified a group of patients more likely to benefit from revascularization based on 3 key factors: clinical presentation, severity of the renal artery lesion and the state of the kidney beyond the stenotic lesion. In this way, a large proportion of patients can clinically improve after revascularization if their outcomes are considered according to the nature of their clinical presentation.

Estenosis arterial del injerto renal: evaluación de la incidencia mediante ecografía doppler, factores de riesgo y análisis de las complicaciones que pueden afectar a la supervivencia del injerto / Transplant renal artery stenosis: Study of incidence using doppler ultrasound, risk factors and analysis is effect in graft outcomes

Introducción y objetivos La estenosis de la arteria del injerto renal (EAR) es una complicación vascular del trasplante renal cuya incidencia estimada es del 13%, la cual puede causar hipertensión arterial refractaria, disfunción renal y muerte prematura en los receptores. Métodos Se realizó un estudio retrospectivo que incluyó a todos los pacientes sometidos a trasplante renal entre 2014 y 2020. Los pacientes fueron evaluados mediante ecografía doppler renal sistemática tras el trasplante. Para identificar los factores de riesgo independientes de la estenosis de la arteria renal tras el trasplante, realizamos un análisis multivariante. Resultados Se incluyeron 724 trasplantes renales, el 12% eran de donante vivo y el 88% de donante fallecido. La edad media en los receptores era de 54,8 años y en los donantes era de 53. Se diagnosticó estenosis de la arteria del injerto renal en 70 (10%) receptores, la mayoría durante los primeros 6 meses después de la intervención. El 51% de los pacientes con estenosis de la arteria del injerto renal se manejaron de manera conservadora. El análisis multivariante mostró que la diabetes mellitus, el rechazo del injerto, la resutura arterial y el índice de masa corporal del donante eran factores de riesgo independientes de estenosis de la arteria renal después del trasplante. La supervivencia de los injertos con estenosis de la arteria del injerto renal fue del 98% a los 6 meses y del 95% a los 2 años. Conclusiones El uso sistemático de la ecografía doppler en el período inmediatamente posterior al trasplante permitió diagnosticar un 10% de estenosis de la arteria del injerto renal en nuestra cohorte. A pesar de los factores de riesgo mencionados anteriormente, un seguimiento y tratamiento adecuados podrían reducir el riesgo de pérdida del injerto en pacientes con estenosis de la arteria del injerto renal. (AU)

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. The 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. (AU)

Prevalence and Associated Factors of Atherosclerotic Plaque and Stenosis in Renal Arteries: A Community-Based Study.

The epidemiology of renal artery atherosclerosis in community populations is poorly documented. This study aimed to determine the prevalence of renal artery plaque (RAP) and atherosclerotic renal artery stenosis (ARAS), and the association of plaque and stenosis with vascular risk factors and kidney disease markers among community-dwelling adults. We conducted a cross-sectional analysis of the Polyvascular Evaluation for Cognitive Impairment and Vascular Events (PRECISE) study. RAP and ARAS were evaluated by thoracoabdominal computed tomography angiography. A total of 3045 adults aged 50-75 years were included. The prevalence of RAP and ARAS was 28.7% and 4.8%, respectively. The prevalence of RAP and ARAS was 41.3% and 7.7% in individuals aged ≥60 years, 42.9% and 8.7% in hypertensives, and 45.4% and 8.5% in individuals with chronic kidney disease. Older age, hypertension, higher total cholesterol level, and lower high-density lipoprotein cholesterol level were independently associated with RAP and ARAS. A higher urinary albumin-creatinine ratio was independently associated with RAP, whereas a reduced estimated glomerular filtration rate was independently associated with ARAS. In conclusion, there was a non-negligible prevalence of RAP and ARAS among the older, community population in China.

Intravascular ultrasound-guided, lithotrispy facilitated angioplasty for treating a heavily calcified renal artery stenosis.

A 63-year-old woman with uncontrolled hypertension despite taking 5 antihypertensive medications was referred for percutaneous renal artery intervention.

Magnetic Resonance Imaging in Atherosclerotic Renal Artery Stenosis: The Update and Future Directions from Interventional Perspective.

Background: Atherosclerotic renal artery stenosis (ARAS) is a condition where the renal arteries become narrowed due to atherosclerosis, leading to reduced blood flow to the kidneys and various renal complications. The effectiveness of interventional treatments, such as renal artery angioplasty and stenting, remains debated, making patient selection for these procedures challenging. Summary: This review focuses on the diagnosis and management of ARAS, with a particular emphasis on the potential role of functional magnetic resonance imaging (MRI) in evaluating renal function and mechanisms. By summarizing current diagnostic approaches and outcomes of interventional treatments, the review highlights the importance of informed clinical decision-making in ARAS management. Functional MRI emerges as a promising noninvasive tool to assess renal function, aiding in patient stratification and treatment planning. Key Messages: The efficacy of interventional treatments for ARAS requires further investigation and careful patient selection. Functional MRI holds promise as a noninvasive means to assess renal function and mechanisms, potentially guiding more effective clinical decisions in ARAS management. Advancing research in diagnostic methods, particularly functional MRI, can enhance our understanding and improve the treatment outcomes for ARAS patients.

Case report: Endovascular treatment of transplant renal artery stenosis in patient with normal color duplex ultrasound of the renal artery.

Key Clinical Message: Proper diagnosis and treatment of vascular stenosis which is a possible complication of renal transplant is important in improving patients' quality of life and prognosis. Abstract: One known consequence among recipients of renal transplants is graft renal artery stenosis. Early identification and therapy are crucial to avoid graft malfunction and the serious consequences that might arise due to elevated hypertension in several organs. We report a rare case of transplant renal artery stenosis in a mid-aged woman who presented with edema, hypertension, and increased creatinine 2 months after kidney transplant. The patient had normal renal arterial resistive index (RI) and perfusion index (PI), and there was only a modest decrease in perfusion on duplex ultrasound. Following the patient's renal stenting treatment, angiographic resolution was observed. After 14 days of regulated blood pressure following renal artery stenting, she was discharged from the hospital with her edema resolved. Considering complications in patients with clinical manifestations such as hypertension resistant to treatment and graft dysfunction, vascular stenosis is a notable issue to consider even in the context of normal renal arterial RI, PI, and duplex ultrasound. Proper diagnosis and treatment are of importance to improve patients' quality of life and prognosis.

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.

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.