Renal Artery Stenosis In Patients Research Articles

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

Key Clinical MessageProper diagnosis and treatment of vascular stenosis which is a possible complication of renal transplant is important in improving patients' quality of life and prognosis.AbstractOne 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.

Outcomes after stenting of renal artery stenosis in patients with high-risk clinical features

BackgroundIn patients with renal artery stenosis, revascularization was seen as a mean to improve outcomes, but large studies failed to show significant benefit in general population. However, data on benefits of renal artery stenting in patients with high-risk features, such as rapidly declining renal function and cardiac destabilization syndromes, are limited, as they were excluded from trials. In this descriptive study, we aimed to evaluate short- and long-term outcomes in high-risk patients with renal artery stenosis, treated by angioplasty and stenting. We have retrospectively interrogated our local databases for renal artery percutaneous interventions; patients at high-risk (rapidly declining renal function; stable chronic renal failure and bilateral renal artery disease; severe hypertensive crisis) were selected for the current analysis.ResultsOf 30 patients undergoing renal artery stenting, 18 patients were deemed "high-risk." On short term, good in-hospital control of hypertension and cardiac stabilization were obtained in all patients. Renal function improved significantly only in patients admitted with rapidly declining renal function, with significant creatinine level fall from median 3.98 mg/dL to 2.02 mg/dL, p = 0.023. However, for the whole group, creatinine change was non-significant (− 0.12 mg/dL, p = NS). On the long term, five patients (27.8%) ended-up on chronic hemodialysis and six patients died (33.3%) after a median of 20 months. No death occurred during the first year after the procedure.ConclusionsPercutaneous procedures are feasible and safe in patients with high-risk renal artery stenosis, especially in those with rapidly declining renal function, probably saving some of them from the immediate need for renal replacement therapy, but long-term results are negatively influenced by the precarious general and cardio-vascular status of these patients and by the pre-existing significant renal parenchymal disease, non-related to the renal artery stenosis.

Recurrent flash pulmonary edema in unilateral renal artery stenosis with contralateral kidney shrinkage: A case report.

Flash pulmonary edema is a critical medical condition characterized by sudden and severe fluid accumulation in the lungs, which poses an immediate and life-threatening emergency. This can arise from a variety of underlying causes. This manuscript presents a case of recurrent pulmonary edema that was successfully managed through the insertion of a renal artery stent. A 78-year-old woman visited the emergency room with recurrent acute dyspnea. Computed tomography renal angiography revealed renal artery stenosis of a single-functioning kidney. Flash pulmonary edema caused by renal artery stenosis of a functioning single kidney. Percutaneous transluminal angioplasty and stenting were performed for the renal artery stenosis. The patient's kidney function rapidly improved, and she has been free of flash pulmonary edema for 2 years. Flash pulmonary edema can have various causes and can immediately be a life-threatening emergency. However, it can be treated with percutaneous revascularization if it is caused by renal artery stenosis. This case report reinforces the importance of accurate and immediate diagnosis when dealing with flash pulmonary edema. This case emphasizes the potential therapeutic benefit of renal artery stenting in the management of flash pulmonary edema caused by renal artery stenosis in patients with a single-functioning kidney.

Renal perfusion improvement in the perioperative period after unilateral endovascular revascularization in patients with atherosclerotic renal artery stenosis.

The clinical benefits of endovascular treatment in renal artery stenosis (RAS) remain controversial. This study used an intraoperative renal perfusion imaging technique, called flat-panel detector parenchymal blood volume imaging (FD-PBV), to observe the change in renal perfusion after endovascular treatment in RAS. In a prospective, single-center study, we assigned 30 patients with atherosclerotic RAS who underwent endovascular treatment between March 2016 and March 2021. The preoperative and postoperative results of renal perfusion, blood pressure, and renal function, were compared. Both median kidney volume (p < 0.001) and median preoperative mean density of contrast medium (MDCM) (p = 0.028) increased significantly after endovascular treatment. The ratio of postoperative and preoperative MDCM differed greatly among the patients. For patients with preoperative MDCM <304.0 HU (Subgroup A, 15 cases), MDCM significantly increased after treatment (p = 0.001) and 12 (80.0%) patients had more than 10% increase in renal perfusion. For patients who had relatively high preoperative renal perfusion (MDCM ≥304.0 HU, Subgroup B, 15 cases), preoperative and postoperative MDCM were similar (p = 0.776). On the other hand, the serum creatinine levels significantly decreased in Subgroup A (p = 0.033) and fewer antihypertensive drugs were used after endovascular revascularization (p = 0.041). The preoperative and postoperative creatinine levels and number of antihypertensive drugs were similar in Subgroup B. During the perioperative period, RAS patients with relatively low preoperative renal perfusion levels had greater improvement in renal perfusion, renal function, and blood pressure control after endovascular treatment. The improvement of renal function needs to be confirmed by long-term follow-up.

Transplant renal artery stenosis: utilization of machine learning to identify ancillary sonographic and doppler parameters to predict stenosis in patients with graft dysfunction

To determine if ancillary sonographic and Doppler parameters can be used to predict transplant renal artery stenosis in patients with renal graft dysfunction. IRB-approved, HIPAA-compliant retrospective study included 80 renal transplant patients who had renal US followed by renal angiogram between January 2018 and December 2019. A consensus read of two radiologists recorded these parameters: peak systolic velocity, persistence of elevated velocity, grayscale narrowing, parvus tardus, delayed systolic upstroke, angle of the systolic peak (SP angle), and aliasing. Univariate analysis using t-test or chi-square was performed to determine differences between patients with and without stenosis. P values under 0.05 were deemed statistically significant. We used machine learning algorithms to determine parameters that could better predict the presence of stenosis. The algorithms included logistic regression, random forest, imbalanced random forest, boosting, and CART. All 80 cases were split between training and testing using stratified sampling using a 75:25 split. We found a statistically significant difference in grayscale narrowing (p=0.0010), delayed systolic upstroke (p=0.0002), SP angle (p=0.0005), and aliasing (p =0.0024) between the two groups. No significant difference was found for an elevated peak systolic velocity (p =0.1684). The imbalanced random forest (IRF) model was selected for improved accuracy, sensitivity, and specificity. Specificity, sensitivity, AUC, and normalized Brier score for the IRF model using all parameters were 73%, 81%, 0.82, and 69 in the training set, and 78%, 58%, 0.78, and 80 in the testing set. VIMP assessment showed that the combination of variables that resulted in the most significant change of the training set performance was that of grayscale narrowing and SP angle. Elevated peak systolic velocity did not discriminate between patients with and without TRAS. Adding ancillary parameters into the machine learning algorithm improved specificity and sensitivity similarly in the training and testing sets. The algorithm identified the combination of lumen narrowing coupled with the angle of the systolic peak as better predictor of TRAS. This model may improve the accuracy of ultrasound for transplant renal artery stenosis.

Concentration of serum uric acid in patients with Renal Artery Stenosis and Hypertension prEdict Future nephropathy and death: C-RASHEF study.

Since both serum uric acid (SUA) and renal artery stenosis (RAS) are associated with atherosclerotic events and renal events, it is interesting to investigate whether SUA could predict long-term outcome in patients with RAS. Patients were enrolled from inpatients from 2010 to 2014, must be ≥40-year-old. There were 3269 hypertensive patients enrolled, including 325 RAS patients. Endpoints included all-cause death and new or worsening nephropathy (NNP). In analysis for all-cause mortality, associations between SUA and risk of all-cause mortality were an arising curve in total population, a U-shape curve in non-RAS population, and an arising curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of all-cause mortality was still an arising curve in total population. In analysis for NNP, associations between SUA and risk of NNP were a declining curve in total population, not significant in non-RAS population, and a U-shape curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of NNP in total population was no longer significant. Not only association curve of SUA with mortality in non-RAS patients is different from association curve in RAS patients, but also association curve of SUA with NNP in non-RAS patients is different from association curve in RAS patients. The authors conclude that mechanisms of uric acid for mortality and NNP in RAS patients are different from non-RAS patients. In addition to renal vascular obstruction, uric acid is another significant factor for NNP and death in RAS patients.

Cardiovascular Disease Prevention in Patients With Atherosclerotic Renovascular Disease-Induced Resistant Hypertension: Further Considerations for 24-Hour BloodPressure Profiles.

Cardiovascular Disease Prevention in Patients With Atherosclerotic Renovascular Disease-Induced Resistant Hypertension: Further Considerations for 24-Hour BloodPressure Profiles.

CARDIOHEMODYNAMIC AND PROGNOSTIC SIGNIFICANCE OF RENAL ARTERY STENTING IN PATIENTS WITH CORONARY ARTERY DISEASE

The aim of the study is to evaluate cardiohemodynamic and prognostic significance of endovascular revascularization of renal arteries (ERRA) in patients with coronary artery disease (CAD).&#x0D; Materials and Methods. The authors examined 106 patients (84 men, 22 women; mean age 53±15). All the patients underwent both coronary angiography and renal artery angiography to verify chronic CAD. The authors analyzed the incidence and severity of arterial hypertension, the results of coronary and renal artery angiography, the outcomes of endovascular management of renal artery stenosis (RAS), and all-cause mortality rates. The follow-up period lasted for 10 years.&#x0D; Results. CAD was detected in 61 patients (58 %). Synchronous coronary and renal artery damage was detected in 12 patients (19.7 %), including hemodynamically significant renal artery stenosis (9 patients (14.8 %)). Eight patients underwent renal artery stenting. Arterial hypertension was observed in 58 of 61 patients (95.1 %) with verified CAD, including all the patients with synchronous coronary and renal artery damage. Seventeen patient (16 %) died during the monitoring period. During a 10-year period, 3 people (25 %) died from all causes in the group of RAS patients, while 14 people (14.8 %) died in the group of patients without RAS (χ=1.22; р=0.37). Twelve months after renal artery stenting, there was a decrease in systolic blood pressure load, a decrease in the number of unfavorable blood pressure profiles, and a decrease in end-diastolic dimension.&#x0D; Conclusions. In the medium term, ERRA is associated with a decrease in hypertensive load indices and systolic BP variability, an improvement of circadian blood pressure profiles, and a decrease in left ventricle end-diastolic and left atrium dimensions. Renal artery stenosis and ERRA did not significantly affect mortality over a 10-year follow-up.

Percutaneous balloon and stent angioplasty in children with renal artery stenosis

Renal artery stenosis(RAS) is responsible for about 10% of secondary childhood hypertension that lead to end organ dysfunction and mortality. Angioplasty is gold intervention approach for stenosis treatment. However, there are rare studies in term of the pediatric RAS and angioplasty outcome in the children. In this Single-center, retrospective study, the medical records of pediatric RAS patients were analyzed who referred for Rajaei cardiovascular medical and research center of Tehran from 2005 to 2018. Of these, 13 patients underwent PTA (Percutaneous transluminal angioplasty) treatment. Demographic data, etiology, symptoms, presenting feature, stenosis, blood pressure, number of drugs, hematological and biochemical parameters, intervention type, treatment complication and echocardiography reports were reviewed. Statistical analysis was performed with SPSS Version 23 software package. Descriptive statistics, Chi square and Pearson correlation, parametric and non-parametric tests used for statistical analysis. Our results showed headache and cardiovascular damage was most common presenting feature. PTA intervention is effective in order of 50% of patients that reduced the blood pressure and improved medical therapy. The numbers of administrated antihypertensive drugs were reduced after PTA therapy. Restenosis and contrast induced-nephropathy emerge as major complications. Higher stenosis present but not lesion length had a negative relationship with treatment success and outcome. Age, ESR and serum potassium levels predicted the treatment outcome significantly. In conclusion, this study confirm the effectiveness of PTA in the treatment of pediatric RAS but need more technical and biomedical improvement to yield higher success and outcome.

Development and Validation of a Prognostic Nomogram for Prognosis in Patients With Renal Artery Stenosis.

Background and ObjectiveRenal artery stenosis (RAS) is associated with an increased risk of renal function deterioration (RFD). Our previous study showed that renal cortical blood perfusion assessed by contrast-enhanced ultrasound (CEUS) was an important related factor for RFD in RAS patients. Based on several conventional related factors confirmed by previous studies, we aimed to establish and verify a CEUS+ scoring system to evaluate the risk of RFD at 1 year of follow-up in RAS patients.MethodsThis study was a single-center retrospective study. A total of 497 elderly RAS patients (247 in the training group and 250 in the verification group) admitted to the Beijing Hospital from January 2016 to December 2019 were included. The baseline characteristics of the patients on admission (including general conditions, previous medical history, blood pressure, blood creatinine, RAS, and cortical blood perfusion in the affected kidney) and renal function [glomerular filtration rate (GFR)] at 1-year of follow-up were collected. We used the univariate and multivariate logistic regressions to establish a CEUS+ scoring system model, the receiver operating characteristic (ROC) curve and area under the curve (AUC) to evaluate prediction accuracy, and the decision curve analysis and nomogram to evaluate the clinical application value of CEUS+ scoring system model.ResultsAmong the 497 patients enrolled, 266 (53.5%) were men, with an average age of (51.7 ± 19.3) years. The baseline clinical-radiomic data of the training group and the verification group were similar (all p > 0.05). Multivariate logistic regression analysis results showed that age [Odds ratio (OR) = 1.937, 95% confidence interval (CI): 1.104–3.397), diabetes (OR = 1.402, 95% CI: 1.015–1.938), blood pressure (OR = 1.575, 95% CI: 1.138–2.182), RAS (OR = 1.771, 95% CI: 1.114–2.816), and area under ascending curve (AUCi) (OR = 2.131, 95% CI: 1.263–3.596) were related factors for the renal function deterioration after 1 year of follow-up (all p < 0.05). The AUC of the ROC curve of the CEUS+ scoring system model of the training group was 0.801, and the Youden index was 0.725 (specificity 0.768, sensitivity 0.813); the AUC of the ROC curve of the validation group was 0.853, Youden index was 0.718 (specificity 0.693, sensitivity 0.835). There was no significant difference in ROC curves between the two groups (D = 1.338, p = 0.325). In addition, the calibration charts of the training and verification groups showed that the calibration curve of the CEUS+ scoring system was close to the standard curve (p = 0.701, p = 0.823, both p > 0.10).ConclusionThe CEUS+ scoring system model is helpful in predicting the risk of worsening renal function in elderly RAS patients.

Value of contrast-enhanced ultrasound for diagnosis and follow-up of renal artery stenosis in patients with chronic kidney disease.

To evaluate whether contrast-enhanced ultrasound (CEUS) is an accurate, non-nephrotoxic diagnostic method and follow-up tool for use in patients with chronic kidney disease (CKD) and renal artery stenosis (RAS). In this prospective and monocentric study, we compared the sensitivity and specificity of CEUS for the diagnosis of RAS in CKD patients, using digital subtraction angiography (DSA) or computed tomographic angiography (CTA) as the gold standard methods. Further, the value of CEUS for distinguishing restenosis from other diseases was assessed. The ultrasound physicians conducted the examinations and served as the CEUS report readers who were blinded to the DSA or CTA results. Patients with RAS (n = 60) were enrolled. Average patient age was 64.4 ± 18.0years and median estimated glomerular filtration rate was 66.1mL/min/1.73 m2. CEUS was used to image 94 stenotic renal arteries and DSA- or CTA-verified stenosis was present in 96 renal arteries. The kappa value for CEUS was 0.776 (P < 0.001), with an accuracy of 92.5%, a sensitivity of 94.7%, and a specificity of 84.0%. The accuracy of CEUS was the same for the diagnosis of the CKD3b-5 group as for the CKD1-3a group (100% vs. 87.5%, P = 0.148). There was no difference in CEUS accuracy for the diagnosis of Takayasu RAS compared with atherosclerotic RAS (95.8% vs. 91.7%, P = 0.795). Twenty-nine CEUS examinations were performed to follow in-stent restenosis or progression of RAS, with a median follow-up time of 5.0months (range 1.0-20.0). Two cases of in-stent restenosis in patients suffering from deteriorating kidney function and recurrent hypertension were examined by CEUS. CEUS examination is a credible alternative for diagnosing moderate and severe RAS in patients with CKD, and is a reliable tool for follow-up surveillance after renal artery revascularization treatment. It shouldn't be thought as a color-coded duplex ultrasonography rescue in these patients.

Concurrent Primary Aldosteronism and Renal Artery Stenosis: An Overlooked Condition Inducing Resistant Hypertension.

To explore the clinical features of coexisting primary aldosteronism (PA) and renal artery stenosis (RAS), we retrospectively analyzed records from 71 patients with PA with RAS and a control group of 121 patients with PA without RAS. Aldosterone-to-renin concentration ratio tests and computerized tomography (CT) scanning of the adrenal and renal arteries were routinely conducted to screen for PA and RAS. Color Doppler flow and/or magnetic resonance imaging were used as substitute testing of patients for whom CT was contraindicated. Standard percutaneous renal arteriography (PTRA) was considered for patients with RAS exceeding 70% based on non-invasive tests and for those without PTRA contraindications. The patients with PA with RAS were further divided into severe (RAS>70%) and moderate (50% < RAS <70%) RAS groups. The prevalence of RAS among PA patients was 6.9% (71/1,033), including 3.2% (33/1,033) with severe RAS. Compared with the PA without RAS group, the severe RAS group showed higher levels of systolic blood pressure (SBP) (171.82 ± 18.24 vs. 154.11 ± 18.96 mmHg; P < 0.001) and diastolic BP(DBP) (110.76 ± 15.90 vs. 91.73 ± 12.85 mmHg; P < 0.001) and prevalence of resistant hypertension (RH) (90.9 vs. 66.9%; P = 0.008), whereas the moderate RAS group merely showed higher DBP (98.63 ± 14.90 vs. 91.73 ± 12.85 mmHg; P = 0.006). The direct renin concentrations (DRCs) (5.37 ± 3.94 vs. 3.71 ± 2.10 μU/mL; P < 0.001) and false-negative rate (33.8 vs. 3.3%; P < 0.01) of PA screening tests were significantly higher in the PA with RAS group than in the control group, but only in severe RAS group, in subgroup analysis. Among patients who underwent successful treatment for severe RAS, mean DRC decreased from 11.22 ± 9.10 to 3.24 ± 2.69 μIU/mL (P < 0.001). Overall, the prevalence of RH decreased from 81.7 to 2.8% (P < 0.001) when both PA and RAS were treated with standard methods. PA with concurrent severe RAS is a condition that induces RH. PA can be easily missed in patients with coexisting RAS. RAS patients with RH after successful revascularization for RAS should be evaluated for coexisting PA.

Whole kidney and renal cortex segmentation in contrast-enhanced MRI using a joint classification and segmentation convolutional neural network

Contrast-enhanced magnetic resonance imaging (CE-MRI) is one of the methods routinely used in clinics for the diagnosis of renal impairments. It allows assessment of kidney perfusion and also visualization of various lesions and tissue atrophy due to e.g. renal artery stenosis (RAS). An important indicator of the renal tissue state is the volume and shape of the kidney. Therefore it is highly desirable to equip radiological units in clinics with the software capable of automatic segmentation of the kidneys in CE-MRI images. This paper proposes a solution to this task using an original architecture of a deep neural network. The proposed design employs a three-branch convolutional neural network specialized in: 1) detection of renal parenchyma within an MR image patch, 2) segmentation of the whole kidney and 3) annotation of the renal cortex. We tested our architecture for normal kidneys in healthy subjects and for poorly perfused organs in RAS patients. The accuracy of renal parenchyma segmentation was equal to 0.94 in terms of the intersection over union (IoU) ratio. Accuracy of the cortex segmentation depends on the level of tissue health condition and ranges from 0.76 up to 0.92 of IoU.

Prevalence of visceral artery involvement in patients with peripheral artery disease found on run-off MRA

BackgroundIn patients with peripheral artery disease (PAD), run-off MR-angiography (MRA) is a commonly performed diagnostic test to obtain high-resolution images for evaluation of the arterial system from the aorta through the distal run-off vessels. The aim of this study was to investigate the prevalence of visceral artery involvement (VAI) in patients with PAD and leg symptoms examined with run-off MRA.MethodsWe retrospectively analyzed 145 patients (median age 68 years, range 27–91) who underwent MRA due to known or suspected PAD at our institution between 2012 and 2018. MRA examinations were re-evaluated for visceral artery stenosis. Patient dossiers were reviewed to determine cardiovascular risk factors, kidney function and Fontaine stage of PAD.ResultsInvolvement of at least one visceral artery with ≥ 50% diameter stenosis was found in 72 (50%) patients. There were no differences in age, gender, MRA indication, Fontaine stage, levels of C-reactive protein (CRP), cardiovascular risk factors or vascular comorbidities between patients with and without VAI. Renal artery (RA) involvement with ≥ 50% diameter stenosis was observed in 28 (20%) of patients. Patients with involvement of the RA were more likely to suffer from hypertension (79 vs. 54%, p = 0.019) and reduced renal function (glomerular filtration rate 70 vs. 88 mL/min/1.73m2, p = 0.014).ConclusionVisceral artery stenosis can be seen in half of patients with known or suspected PAD and leg symptoms on run-off MRA. Investigating for RA stenosis in patients with PAD and hypertension and/or impaired renal function may have high diagnostic yield.

Short Term Prognosis of Renal Artery Stenosis Secondary to Acute Type B Aortic Dissection With TEVAR

Objective: To determine the effect of renal artery stenosis (RAS) resulting from acute type B aortic dissection (ATBAD) with thoracic endovascular aortic repair (TEVAR) on early prognosis in patients with ATBAD.Methods: A total of 129 ATBAD patients in the National Acute Aortic Syndrome Database (AASCN) who underwent TEVAR between 2019 and 2020 were enrolled in our study. Patients were divided into two groups: the RAS group and the non-RAS group.Results: There were 21 RAS patients (16.3%) and 108 non-RAS patients (83.7%) in our cohort. No patient in our cohort died during the 1-month follow-up. There was no significant difference in preoperative creatinine clearance rate (CCr) between the two groups (90.6 ± 46.1 μmol/L in the RAS group vs. 78.7 ± 39.2 μmol/L in the non-RAS group, P = 0.303) but the RAS group had a significantly lower estimated glomerular filtration rate (eGFR) than the non-RAS group (83.3 ± 25.0 vs. 101.9 ± 26.9 ml/min, respectively; P = 0.028).One month after TEVAR, CCr was significantly higher (99.0 ± 68.1 vs. 78.5 ± 25.8 ml/min, P = 0.043) and eGFR (81.7 ± 23.8 vs. 96.0 ± 20.0 ml/min, P = 0.017) was significantly lower in the RAS group than in the non-RAS group.Conclusions: In ATBAD, RAS could result in acute kidney injury (AKI) in the early stage after TEVAR. The RAS group had a high incidence of hypertension. These results suggest that patients with RAS may need further treatment.

Clinical characteristics of concurrent primary aldosteronism and renal artery stenosis: A retrospective case–control study

ABSTRACT Background: Rare cases of concurrent primary aldosteronism (PA) and renal artery stenosis (RAS) have been reported. Methods: In this retrospective case–control study, we selected a cohort of 10 PA with RAS patients and a control group of 20 PA without RAS patients from January 1, 2006, to January 1, 2016. Results: All patients presented with refractory hypertension, and a nonstatistically significant trend toward lower mean serum potassium was seen in the PA with RAS group (p =.07). PA with RAS patients had lower mean orthostatic aldosterone-to-renin ratios (38.4 ± 41.4 ng dL−1/ng mL−1 h−1 vs. 87.4.4 ± 38.4 ng dL−1/ng mL−1 h−1, respectively; p < .01) and a higher false-negative rate (50% vs. 15%, respectively; p < .05) compared with controls. All misdiagnosed patients had the diagnosis of PA confirmed when we revaluated the repeated screening and confirmative tests because of residual hypertension or hypokalemia after successful revascularization of renal artery stenosis. Conclusions: PA is easily missed in patients with RAS because of the high false-negative rate for screening tests. RAS patients with residual hypertension after successful renal angioplasty should be monitored for coexisting PA. Reevaluation of screening and confirmatory tests is helpful in establishing the correct diagnoses.

Carotid intraplaque neovascularization predicts atherosclerotic renal artery stenosis in patients with carotid artery stenosis

Background and aimsThis study aimed to examine whether intraplaque neovascularization (IPN) of carotid plaques, as characterized by contrast-enhanced ultrasound (CEUS), is associated with atherosclerotic renal artery stenosis (ARAS) in patients with normal kidney function. Methods and resultsWe investigated carotid IPN using CEUS in 198 consecutive patients with normal kidney function with and without ARAS. IPN was graded on the basis of the presence and location of microbubbles within each plaque (0, no visible microbubbles in the plaque; 1, moderate microbubbles confined to the shoulder and/or adventitial side of the plaque; and 2, extensive microbubbles throughout the plaque). The grades of each plaque were averaged to obtain an overall score per patient. ARAS was determined angiographically. We found that a higher CEUS-assessed carotid IPN score was associated with ARAS (Odd Ratio, OR: 7.281; 95% Confidence Interval, 95% CI: 3.246–16.336; P < 0.001). Furthermore, an IPN score >1.75 predicted severe stenosis with a sensitivity of 81% and specificity of 58%. Compared with using the IPN score alone, the addition of the homocysteine (HCY) cutoff value (>22.5 mmol/L) resulted in a stronger predictive value (Area Under Curve, AUC: 0.893 vs 0.834; P < 0.001) for severe ARAS. ConclusionCarotid plaque neovascularization combined with HCY levels is predictive of severe ARAS in patients with normal kidney function. CEUS-assessed carotid IPN is clinically useful for stratification of ARAS in patients with normal kidney function.

Renal Artery Stenosis As Etiology of Recurrent Flash Pulmonary Edema and Role of Imaging in Timely Diagnosis and Management.

Renal hypoperfusion from renal artery stenosis (RAS) activates the renin-angiotensin system, which in turn causes volume overload and hypertension. Atherosclerosis and fibromuscular dysplasia are the most common causes of renal artery stenosis. Recurrent flash pulmonary edema, also known as Pickering syndrome, is commonly associated with bilateral renal artery stenosis. There should be a high index of clinical suspicion for renal artery stenosis in the setting of recurrent flash pulmonary edema and severe hypertension in patients with atherosclerotic disease. Duplex ultrasonography is commonly recommended as the best initial test for the detection of renal artery stenosis. Computed tomography (CT) angiography (CTA) or magnetic resonance (MR) angiography (MRA) are useful diagnostic imaging studies for the detection of renal artery stenosis in patients where duplex ultrasonography is difficult. If duplex ultrasound, CTA, and MRA are indeterminate or pose a risk of significant renal impairment, renal angiography is useful for a definitive diagnosis of RAS. The focus of medical management for RAS relies on controlling renovascular hypertension and aggressive lifestyle modification with control of atherosclerotic disease risk factors. The restoration of renal artery patency by revascularization in the setting of RAS due to atherosclerosis may help in the management of hypertension and minimize renal dysfunction.

Occurrence and Risk Factors of Renal Artery Stenosis in Patients Undergoing Abdominal Computed Tomography Angiography, a One-Year Study in a Tertiary Hospital in Manila

Renal artery stenosis (RAS) is one of the most common primary diseases of the renal arteries. It is associated with hypertension as well as ischemic renal disease. Its concomitant presence constitutes a high cardiovascular risk, thus timely diagnosis is important. This study aims to determine the occurrence of RAS in patients undergoing abdominal CT angiography and determines other factors that predict the highest-risk subset who have significant renal artery narrowing.

Serum levels of neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and cystatin-C in renal artery stenosis: A pilot study

Background: The present pilot study evaluated the potential of newer renal biomarkers (neutrophil gelatinase-associated lipocalin [NGAL], cystatin-C [Cys-c], and kidney injury molecule-1 [KIM-1]) in estimating subclinical renal injury due to renal artery stenosis (RAS). Materials and Methods: A total of 13 patients of magnetic resonance angiography confirmed RAS and 14 normotensive healthy controls were enrolled in the study after obtaining ethics approval and informed consent. Serum was collected from participants to check for serum levels of NGAL, KIM-1, and Cys-c by quantitative enzyme immunoassay. The data of RAS patients were compared and analyzed against the data of healthy controls. Results: sNGAL, sKIM-1, and sCys-c values in RAS patients showed rising trend as compared to normal healthy control; however, the difference in their values was not statistically significant. This could be due to small and heterogeneous sample size. However, statistically significant difference was noted in the values of sNGAL and sCys-c between healthy controls and RAS patients with abnormal serum creatinine. This difference in the values of these biomarkers was also statistically significant between RAS patients with normal and elevated serum creatinine. Conclusion: In RAS patients, sNGAL, sCys-c, and sKIM-1 seem to have potential as an early biomarker of kidney injury.