Diagnosis Of Renal Artery Stenosis Research Articles

AORTIC STENOSIS AND ULTRASOUND EVALUATION OF RENAL VESSELS IN HYPERTENSIVE PATIENTS

Objective: Aortic stenosis (AS) and arterial hypertension often clusterize and increase cardiovascular disease burden. Renal artery (RA) stenosis, the main form of secondary hypertension, can act as an upstream factor of resistance at the same way of AS. Aim of the study: to investigate if the presence of AS is able to interfere with the ultrasound (US) parameters in the diagnosis of RA stenosis. Design and method: In hypertensive subjects with AS we evaluated US indirect parenchymal parameters: resistive index (RI) and index of maximal systolic acceleration (AImax: the maximal acceleration of flow waveform in early systole divided by the peak systolic velocity), and US direct RA parameters: peak systolic velocity (PSV) and Renal/Aortic Ratio (RAR). Results: We compared hypertensive patients (mean age 74 years) with preserved left ventricular function with severe AS (n=18) or mild AS (n=21). No statistically differences were detected between groups regarding gender, age, smoke, ABI, CV risk factors, lipids, and renal function. Direct US parameters of RA did not differ significantly between patients with severe or mild AS (mean PSV 113 vs 127 cm/sec; mean RAR 1.3 vs 1.6). RI showed the same behavior (0.75 vs 0.73). AImax was significantly lower in patients with severe vs mild AS (8.74 vs 15.56 1/sec, p<0.0005). We found an inverse correlation between AImax and the mean (r2=0.435) and peak (r2=0.424) transvalvular gradient. Among 14 patients with severe AS underwent correction of valvular disease. At 6 months, US showed a significant increase in AImax (from 10.0 to 19.8 1/sec, p<0.005), while RI did not differ significantly (0.74 vs 0.73). Conclusions: Severe AS act as a proximal resistance that can attenuate the systolic acceleration phase of the flow profile of the renal intraparenchymal vessels, in particular of AImax, which is restored after surgical correction of the valve defect. Presence of AS may affect the diagnostic workup of RA stenosis.

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

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. 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. 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. The DL multimodal fusion model shows promising results in assisting RAS diagnosis.

Application of simple ultrasound Doppler hemodynamic parameters in the diagnosis of severe renal artery stenosis in routine clinical practice.

Doppler ultrasound (DUS) is recommended in first-line imaging for the diagnosis of renal artery stenosis (RAS). However, the correct selection of Doppler direct or indirect parameters and their optimal thresholds remain controversial. This study explored simple ultrasound Doppler parameters to diagnose severe RAS (RAS ≥70%) in routine clinical practice. In this retrospective study, patients with clinically suspected renovascular hypertension who first underwent renal artery DUS and contrast-enhanced ultrasound (CEUS) and subsequent digital subtraction angiography (DSA) or computed tomography angiography (CTA) were consecutively included. Clinical characteristics and ultrasound Doppler hemodynamic parameters were collected, including peak systolic velocity (PSV), the ratio of the peak velocities in the renal artery and the aorta (RAR), the ratio of the peak velocities in the renal artery and the segmental artery (RSR), and the ratio of the peak velocities in the renal artery and the interlobar artery (RIR). All enrolled patients were divided into two groups based on the degree of diameter reduction: a severe stenosis group (diameter reduction ≥70%) and a non-severe stenosis group (diameter reduction <70%). Logistic regression analysis was performed to determine the independent predictors for severe stenosis. Receiver operating characteristic curves and areas under the curve were used to evaluate the diagnostic performance of the ultrasound Doppler parameters. A total of 85 patients (106 renal arteries) with RAS were included in this study. The optimal thresholds of PSV in the main renal artery and the PSV ratios for diagnosing severe RAS obtained via receiver operating characteristic curves were 249.5 cm/s for PSV, 2.94 for RAR, 5.1 for RSR, and 7.5 for RIR. The areas under the curve of PSV and the ratios all exhibited good diagnostic efficiency (all >0.8). The combination of these four Doppler variables demonstrated a significant benefit to the overall diagnostic value compared with any factor alone [area under the curve (AUC) =0.962; 95% confidence interval (CI): 0.906-0.989; P<0.05]. The combination of PSV and RSR (AUC =0.925; 95% CI: 0.858-0.967) exhibited comparable diagnostic efficiency to the combination of four ultrasonographic variables (z statistic =1.882; P=0.06). This simple and accurate method to evaluate severe RAS based on the velocity obtained via basic DUS may facilitate the detection of severe RAS in the majority of medical institutions and provide a reliable basis for the selection of proper candidates for further angiography or revascularization.

T-Slip (Time-spatial Labeling Inversion Pulse) in the diagnosis of renal artery stenosis by magnetic resonance imaging

T-Slip (Time-spatial Labeling Inversion Pulse) in the diagnosis of renal artery stenosis by magnetic resonance imaging

PS-C27-4: CONTROLLED RESISTANT HYPERTENSION FOLLOWING A SUCCESSFUL RENAL ARTERY STENTING: A RARE CASE REPORT IN A DEVELOPING COUNTRY

Introduction: Renal artery stenosis is among the etiologies of secondary hypertension in which the diagnosis and therapy are difficult. We report a case of a patient suffered from uncontrollable hypertension with frequent episode of malignant hypertension, treated with renal artery stenting. Case Description: A 36-year-old female visited cardiovascular policlinic on a routine control for her hypertension. Having diagnosed with hypertension for two years, he had several episodes of malignant hypertension. At the beginning of her treatment, she was prescribed an angiotensin-converting-enzyme inhibitor yet her pressure was not only uncontrolled but also worsen. By the visit, she was medicated using two alpha-2-adrenergic agonists, a loop diuretic, a beta-blocker, a calcium-channel blocker, an angiotensin-receptor blocker, and an aldosterone-receptor antagonist without any satisfactory outcome on her blood pressure status. She had a blood pressure of 196/130 mmHg with tachycardia of 112 times/minute. We found cardiomegaly on physical examination which proven by chest x-ray. Echocardiography indicated hypertensive heart disease. Screening for secondary hypertension, including laboratory tests (complete blood count, potassium, sodium, creatinine, fasting glucose, fasting lipid profile, urinalysis, thyroid stimulating hormone, 24H urinary free cortisol) suggested normal results. Renal ultrasound and doppler were also conducted and showed a suspicion of right renal artery stenosis. Therefore, angiography of the renal artery was conducted for diagnostic and therapy when indicated. The angiography suggested a normal left renal artery while the right artery had a 95% stenosis on the proximal part. An intravascular ultrasound-guided percutaneous transluminal angioplasty on her right renal artery was conducted and two vascular stents were implanted. The patient showed a remarkable development following her decreasing blood pressure on follow-up. After 1 week, her blood pressure is now controllable on a single antihypertensive and antiplatelet therapy. Conclusion: The diagnosis and management of a patient with resistant hypertension might be challenging, particularly in the setting of a developing country. Renal artery angiography, among other examination, might be crucial in the diagnosis sequence, yet was not always readily available. We present a case in which diagnosis of renal artery stenosis was made followed by a definite treatment resulting in a remarkable hypertension control. An identifiable etiology is the key to a proper and the best treatment option for the patient.

A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis.

Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters. The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis. The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%. Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

MO400: Treatment of Renal Artery Stenosis: Nephrology, the Best Surgery

Abstract BACKGROUND AND AIMS Renal artery stenosis causes hypertension in 10–40% of severe cases or refractory to treatment. As a gold standard test for its diagnosis, we have arteriography, which allows the interventional therapeutic option, through angioplasty and/or stenting. There is no consensus on which patient profile would be the optimal candidate for each treatment. We tried to reach an answer by studying a cohort of 25 patients from our centre with a diagnosis of renal artery stenosis in the last 5 years. The objective was to assess the efficacy of isolated or interventional medical treatment with respect to renal function and the number of antihypertensive drugs. METHOD A retrospective observational cohort study was conducted. The study population was the patients who underwent renal arteriography in the last 5 years in our center (n = 25). We define significant stenosis as greater than 60%, bilateral involvement or of other main arteries. We compared the evolution of glomerular filtration in stages (KDIGO), proteinuria (albumin/creatinine ratio in urine) and number of antihypertensive drugs before and 6 months after the therapy used. RESULTS Renal arteriography was diagnostic in 18 patients: 13 of them presented significant stenosis, performing angioplasty in 4, stenting in 6 and angioplasty + stenting in 3. One antihypertensive drug was reduced in 17% of the patients, two in 22%, and one drug was increased in one of them. In 83% of the patients, the KDIGO stage of renal function did not change after treatment. An improvement was observed in three patients, who only received medical treatment. No differences were found in the evolution of proteinuria. CONCLUSION There were no statistically significant differences in renal function and the number of antihypertensive drugs between isolated medical versus medical and interventional treatment. It is necessary to expand the patient database, or start multicenter studies, to improve the significance.

Role of Contrast-Enhanced Ultrasound in the Evaluation of Patients With Suspected Renal Arterial Stenosis.

ObjectivesTo explore the role of Contrast-enhanced ultrasound (CEUS) in the evaluation of patients with suspected renal artery stenosis and analyze the causes of the misdiagnosis and missed diagnosis.MethodsThe data of 40 patients (80 renal arteries) diagnosed with RAS by CEUS in Beijing Hospital from September 2018 to October 2020 were compared with their digital subtraction angiography (DSA) results to analyze the causes underlying missed diagnosis and misdiagnosis of RAS by CEUS.Results1. Compared with the gold standard DSA results, the AUC of the ROC curve of CEUS in detecting normal renal artery and renal artery stenosis was 0.961, the sensitivity was 96.4%, the specificity was 95.8%, and the Kappa value of the consistency analysis was 0.912 (P < 0.01); 2. Compared with the gold standard DSA results, the ROC curve of CEUS in distinguishing renal artery stenosis ≥70% from <70% stenosis has an AUC of 0.916, a sensitivity of 90.9%, a specificity of 92.3%, and the Kappa value of the consistency analysis is 0.77 (P < 0.01); 3. CEUS missed two cases (one for mild stenosis and one for moderate stenosis), and the detection rate of renal artery stenosis was 97.5% (78/80); A total of 65 renal arteries diagnosed by CEUS were consistent with DSA, and the diagnostic accuracy of CEUS for the degree of stenosis was 81.25% (65/80); Among the 13 misdiagnosed renal arteries, 4 of them can be corrected to the same degree as DSA by the reference to hemodynamic index, and the diagnosis rate of the degree of renal artery stenosis by ultrasonography (combined with CEUS and hemodynamic indicators) can be improved to 86.25%.Conclusions1. CEUS can clearly show the renal arteries, and is consistent with DSA in distinguishing normal renal artery stenosis from renal artery stenosis, as well as renal artery stenosis ≥70% and <70% stenosis; 2. CEUS showed good performance in detecting normal renal artery and renal artery stenosis, and the missed diagnosis is concentrated on mild and moderate stenosis; 3. CEUS combined with hemodynamic indicators (Doppler ultrasound) can improve the accurate diagnosis rate of renal artery stenosis by ultrasonography; 4. The most important factor for the accurate diagnosis of renal artery stenosis by CEUS is the operator's standardized examination, which is not only related to the duration of the operator has been engaged in this inspection, but also related to whether the operator has received professional training in relevant aspects. These all indicate the necessity and importance of the standardized operation of renal artery contrast-enhanced ultrasound examination, and professional training should be given to operators.

Atherosclerotic renal artery stenosis: epidemiology, etiology, diagnostics and treatment

Paulius Burkauskas1, Karolina Baltrušaitytė1, Ernestas Margelis2 1Lithuanian University of Health Sciences, Academy of Medicine, Faculty of Medicine, Kaunas, Lithuania 2Hospital of Lithuanian University of Health Sciences, Kaunas Clinics, Department of Surgery, Kaunas, Lithuania Abstract Renal artery stenosis is a form of peripheral artery disease that occurs in 1-5% patients with arterial hypertension. Arterial atherosclerosis, which also occurs in other blood vessels, has the greatest impact on the development of the renal artery stenosis. Narrowing of the renal artery activates the renin-angiotensin-aldosterone system, which can cause patients to have high blood pressure that is difficult to correct with multiple medications. As the disease progresses, concentric hypertrophy of the left ventricle develops and, if decompensated, episodes of flash pulmonary edema may occur. Thus, renal artery stenosis affects not only the kidneys but also the entire cardiovascular system. Aim: to select and analyze expert presented causes, diagnostics and recommendations for the treatment of atherosclerotic renal artery stenosis. Methods: the review of literature was conducted using the medical database, selecting publications investigating the burden of atherosclerotic renal artery stenosis. Conclusions: the most common cause of renal artery stenosis is atherosclerosis. The gold standard for the diagnosis of renal artery stenosis is direct renal artery angiography. The main method of treatment for atherosclerotic renal artery stenosis is medication. Keywords: peripheral arterial disease, hypertension, flash pulmonary edema, renal artery stenosis. https://doi.org/10.53453/ms.2021.06.3

The Value of Contrast-Enhanced Ultrasound versus Doppler Ultrasound in Grading Renal Artery Stenosis.

Objective This study is aimed at exploring the accuracy of contrast-enhanced ultrasound (CEUS) in grading renal artery stenosis. Methods 122 renal arteries with suspected renal artery stenosis were selected. DSA, DUS, and CEUS were performed for all patients with suspected renal artery stenosis in the research. DSA was selected as the gold standard. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of CEUS or Doppler ultrasound (DUS) in the diagnosis of renal artery stenosis were analyzed. The consistency between CEUS and digital subtraction angiography (DSA) was compared. The accuracy of DUS or CEUS in grading renal artery stenosis was assessed by the area under the receiver operating characteristic (ROC) curves and compared between groups. Results The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CEUS in the diagnosis of renal artery stenosis were 88.9%, 87.8%, 88.5%, 93.5%, and 80.0%, respectively. There was no significant difference in grading renal artery stenosis between CEUS and DSA (X2 = 0.643, P = 0.424). 77 of the 122 renal arteries were diagnosed with the stenosis rate more than 30% by CEUS. Compared with the results of DSA, the kappa value of CEUS was 0.749 (P < 0.05). Conclusion CEUS is accurate in grading renal artery stenosis, and it may represent the method of choice in diagnosing renal artery stenosis.

Standardized thought of examination and operation with contrast-enhanced ultrasound for diagnosis of renal artery stenosis

肾动脉狭窄（RAS）可导致顽固性高血压和（或）肾功能不全，临床需重视其早期诊断和治疗。本文介绍肾动脉超声造影（CEUS）检查，通过规范检查思路，改良操作方法，显著提高RAS诊断准确率、副肾动脉检出率等，并同步进行肾皮质血流灌注研究，建立了超声造影一站式评估RAS和肾皮质血流灌注的检查方法。.

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

Investigation of the assessment of low degree (

PurposeRenal arterial stenosis can lead to disrupted renal function due to reduced blood flow to the kidneys and is largely thought to be caused by atherosclerosis. Current diagnostic strategies for renal arterial stenosis rely on detecting large degree stenoses (>50%). This study aimed to test the viability of using Doppler ultrasound to assess velocity profiles to detect the presence of low degree (<50%) stenoses. MethodsA series of anatomically realistic renal artery flow phantoms were constructed exhibiting a range of low degree stenoses (symmetric and asymmetric). The behaviour of fluid flow in the phantoms was examined using Doppler ultrasound and analysed to calculate the clinical biomarker, wall shear stress. ResultsA number of fluid behaviours were observed in relation to stenosis degree: asymmetric stenoses tended to result in a skewing of peak velocities away from the centre of the vessel towards the outer wall, the magnitude of increase in velocity was observed to correlate with stenosis degree, and the wall shear stress curves observed large peaks in the presence of even the lowest degree stenosis (20%). ConclusionsDoppler ultrasound could potentially be utilised to diagnose low degree stenoses in a clinical setting. Doppler ultrasound in conjunction with wall shear stress analysis in particular has significant potential in the diagnosis of renal artery stenosis.

Valvular and/or Non-valvular Aortic Pathology Can Bias the Ultrasonographic Diagnosis of Renal Artery Stenosis

Renal artery stenosis (RAS) has been shown to cause a reduction in the index of maximal systolic acceleration (AImax: the maximal acceleration of flow waveform in early systole divided by the peak systolic velocity) of blood in the renal interlobar arteries, caused by local dampening of the pulse wave. In previous studies, AImax demonstrated diagnostic accuracy in terms of negative predictive value, which is useful for screening, but had a relatively low specificity. We hypothesized that an upstream focal resistance, such as an aortic stenosis or aneurysm, could act in the same way as RAS, thus generating false positives in non-stenotic kidneys. We studied 226 patients who underwent a complete protocol for RAS screening. AImax was 6.2 ± 2.9 s–1 and 13.4 ± 3.5 s–1 (mean ± standard deviation) in stenotic and non-stenotic kidneys, respectively. Diagnostic accuracy of ultrasonography with respect to the benchmark of renal computed tomography or magnetic resonance angiography (significant RAS cutoff ≥50%) resulted in 97% sensitivity, 94% specificity and a negative and positive predictive value of 99% and 55%, respectively. Using logistic regression for unexpectedly low AImax in non-stenotic kidneys (AImax cutoff ≤ 9.0 s–1), aortic pathology, such as aortic valve stenosis or aortic arch dilation (as assessed by echocardiography), was found to be the only significant predictor (Χ2 = 33.8, p < 0.0001) of false positive cases compared with clinical and hemodynamic variables. We concluded that the aortic valvular and non-valvular pathology can act as a proximal resistance that can attenuate the Doppler flowmetric parameters, which explore the flow waveform in the renal parenchymal arterial circulation, thus mimicking the presence of a focal resistance in the peripheral vascular region explored.

CLINICAL CHARACTERISTICS AND IMAGING FINDINGS OF RENAL ARTERY STENOSIS CAUSED BY TAKAYASU ARTERITIS AND ATHEROSCLEROSIS IN MIDDLE-AGED PATIENTS

Objective:The etiology diagnosis of renal artery stenosis (RAS) in the middle-aged patients was full of challenges. This study aims to summarize clinical characteristics of Takayasu arteritis induced RAS (TRAS) and atherosclerosis induced RAS (ARAS), in the hope of providing better diagnostic approa

Diagnostic value of contrast-enhanced ultrasound for accessory renal artery among patients suspected of renal artery stenosis

Objective: To evaluate the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of accessory renal artery (ARA) in patients suspected of renal artery stenosis. Methods: Cases were derived from patients suspected diagnosis of renal artery stenosis during October 2017 and July 2018 by CEUS.A total of 28 kidneys with ARA in 25 cases were diagnosed by dynamic continuous observation by two ultrasound physicians separately. If there was disagreement, the superior physician would made the judgment. DSA or CTA examination was performed at the same period, and its consistency with CEUS diagnosis of ARA was analyzed. Results: DSA or CTA identified RAS in 32 ARA, color-coded duplex ultrasonography (CCDS) in 12 and CEUS in 28. The sensitivity in detecting ARA was 37.5% for CCDS and 84.4% for CEUS, the specificity was 0% for CCDS and 94.4% for CEUS, while the accuracy was significantly different with CCDS compared with CEUS (60.0% vs 88.0%). Thus, CEUS significantly improved the ARA detection rate compared with CCDS (84.4% vs 37.5%, χ(2)=15.56, P<0.01). Compared with CTA or DSA, CEUS showed good consistency in ARA diagnosis (kappa value was 0.752, P<0.05). Conclusion: CEUS can display and evaluate ARA in real time accurately, which provides a new technology for further clinical research of ARA.

To determine diagnostic efficiency of vascular color Doppler ultrasound for renal artery stenosis

Background: Early diagnosis of RAS is an important clinical objective since interventional therapy may improve or cure hypertension and preserve renal function. The present study was conducted to determine diagnostic efficiency of vascular color Doppler ultrasound for renal artery stenoses. Materials & Methods: The present study was conducted on 43 suspected of having renovascular arterial hypertension patients of both genders. All patients were subjected to vascular color doppler ultrasound according to the direct technique with the patients in the supine position with low-frequency curve transducers (2 to 3.5 MHz) to allow greater penetration (10-12 cm) of the ultrasound beam.Results: Out of 43 patients, males were 22 and females were 21. Color Doppler of renal arteries, 14 were normal, 12 showed moderate stenosis, 8 had hemodynamically significant stenosis, 7 were obstructed and 2 were inconclusive. The difference was significant (P< 0.05). Sensitivity of color Doppler found to be 92.4%, specificity 91.5%, positive predictive value (PPD) 86.2% and negative predictive value (NPV) 88.1%.Conclusion: Early diagnosis of renal artery stenosis may be helpful in preventing renal hypertension. Color Doppler provides useful information in renal artery stenosis.

Meal Ingestion and Hemodynamic Interactions Regarding Renal Blood Flow on Duplex Sonography: Potential Diagnostic Implications

Splanchnic blood flow changes dramatically after meal ingestion. The present study evaluated physiologic interactions between meal ingestion and hemodynamics with respect to renal blood flow on duplex sonography, assessing the possible influence on Doppler parameters used as diagnostic criteria for renal artery stenosis. Subjects comprised 26 healthy young men (mean age: 22 ± 2 y). Sonographic measurements were made shortly after breakfast and every 1 h thereafter and were compared with values measured before the meal. Peak systolic velocity in the renal artery was elevated post-prandially, peaking at 1 h (90 ± 12 cm/s), compared with pre-prandially (73 ± 10 cm/s, p < 0.01). Similarly, acceleration time at the intra-renal segmental artery shortened to a minimum at 1 h (45 ± 5 ms) compared with baseline (51 ± 6 ms, p < 0.01). The present study indicates that renal blood flow is altered for a few hours after meal ingestion. Attention should be paid to the interpretation of data measured after meals on duplex sonography for diagnosis of renal artery stenosis.

Changes in Antihypertensive Therapy After Renal Transplantation

IntroductionPost-transplant hypertension is extremely frequent, occurring in 60% to 90% of cases. It is involved in the pathogenesis of chronic graft dysfunction and patient survival. ObjectivesWe sought to describe changes in antihypertensive therapy after renal transplantation (RT) depending on the type of pretransplant renal replacement therapy (RRT), hemodialysis (HD) or peritoneal dialysis (PD). MethodsWe performed a retrospective cohort study of RT patients who were divided into 2 groups according to the type of pretransplant RRT (HD group: 69 patients; PD group: 38 patients). Patients with a diagnosis of nonessential hypertension etiology, diagnosis of renal artery stenosis of the graft, active urologic complications, and history of acute graft rejection were excluded. Variables related to chronic kidney disease and RT as well as antihypertensive therapy were studied. ResultsPD patients had reduced number of antihypertensive drugs at 1 month after RT (1.39 ± 1.03) compared with pre-RT (2.16 ± 1.30; P = .001), a trend that was maintained at 6 months (1.70 ± 1.18; P = .06). In HD group, the number of antihypertensive drugs increased at 6 months after RT (1.59 ± 1.17) compared with pretransplant (1.15 ± 1.13; P = .027). The use of calcium channel blockers increased by 10.2% by 1 month (P = .071) and 9.2% (P = .036) by 6 months after RT. ConclusionBy 1 month after RT, antihypertensive therapy was reduced. Calcium channel blockers were the most common drug group, although it is usually necessary to use more than 1 drug.

Hypertension due to renal artery stenosis

A case of a 12-year-old boy with renal artery stenosis as a cause of hypertension is presented. The diagnosis of renal artery stenosis was established based on the bruit heard over costovertebral angle and the increased plasma rennin secretion, and further confirmed by angiogram finding. The detection of bruit, either on the abdomen or costovertebral angle, in association Indones with hypertension should initially lead to the consideration of the presence of renal artery stenosis.