Renal Artery Duplex Ultrasonography Research Articles

Renovascular Hypertension in Chronic Hemodialytic Patient

Background: Hypertension is a major contributor to the development of chronic kidney disease. Data in Indonesia, hypertension is still the most comorbid disease in CKD patients on dialysis (51%). Hypertension in CKD on dialysis patients is common and often uncontrolled. Renovascular hypertension is the most common cause of secondary hypertension. Diagnosis and treatment of RAS is very important, because it can accelerate the achievement of blood pressure targets, reduce the risk and complications due to hypertension.
 Case Report: A 52-year-old woman with CKD has been undergoing hemodialysis for 2 years. Hypertension that was previously well controlled for 2 years required an increase in antihypertensive therapy from 2 to 4 drugs in recent months. On physical examination the blood pressure 180/90 mmHg, pulse 79 bpm, respiration 20/min, temperature 36.7oC. Conjunctiva looks anemic, cardiomegaly, lungs within normal limits, no ascites and edema in the extremities. On renal artery duplex ultrasound examination, right main renal artery acceleration time 147.65 ms, Peak Systolic Velocity (PSV) 31.9 cm/s. RI 0.69 and left main renal artery acceleration time 120.81 ms, PSV 16.9 cm/s, RI 0.61. There was 20-30% left renal artery stenosis, 80% right renal artery stenosis. A stent was placed on the right renal artery. The patient's condition after PTRA improved, but at the next follow-up, mean systole and diastole 170 mmHg and 80 mmHg, respectively. Patient received 4 antihypertensive therapy.
 Conclusion: Renal artery stenosis is a disease that consists of a broad spectrum of different entities with different pathophysiologies that require varied approaches to diagnose and treat. Current diagnostic tools include MRA, CTA and renal artery duplex ultrasonography. Patients with renal parenchymal disease are poorer candidates for revascularization.

How to diagnose renal artery stenosis correctly using ultrasound? Evaluation of results of renal arteries duplex ultrasonography examinations.

Renal artery duplex ultrasonography (RDU) is an effective and non-invasive screening test in diagnosing renal arterystenosis. The discordance of results in multiple RDU is common. We aim to evaluate the discordance and the reasons fordiscordance between diagnoses and measurements from multiple RDU examinations. A retrospectivestudy was performed in 64 examinations of renal arteries from 32 patients that were referred for two or more RDU examinationsand renal artery digital subtraction angiography (DSA) within six months, between August 2013 and January 2016. UsingDSA as gold standard, we divided the renal arteries into three groups: discordant (one diagnosis of RDU was correct andone was wrong), misdiagnosed (neither RDU diagnosis was correct) and correct (both RDU diagnoses were correct) groups.We evaluated the discordance and reasons for discordance of diagnoses and measurements from multiple RDU examinations.Results: Among 64 renal arteries included in this study, 37 renal arteries had two correct diagnoses, 19 renal arteries had twodiscordant diagnoses, and eight renal arteries were misdiagnosed twice by RDU. The discordance of peak systolic velocity(PSV), the ratio between PSV in the renal artery with stenosis and PSV in the aorta (RAR), and tardus-parvus waveform measurementswere clearly higher in the discordant diagnoses group than in the correctly diagnosed group. The most common reasonfor a discordant diagnosis was failure in obtaining correct tardus-parvus waveforms of the interlobar artery (26.31%). Themost common reason for misdiagnosis was the presence of an extremely severe stenosis with an atrophic kidney (31.25%).Overall, 87.50% of patients underwent RDU examinations had correct diagnoses of stenosis or occlusion at least once (includinglocation and degree), as confirmed by DSA. Our study indicates that standard operating procedures andimprovements in examination technique by ultrasound doctors could reduce the discordance between multiple tests.

Co-Existence of Carotid Artery Disease, Renal Artery Stenosis, and Lower Extremity Peripheral Arterial Disease in Patients With Coronary Artery Disease

In atherosclerosis, carotid artery stenosis (CAS), renal artery stenosis (RAS), lower extremity peripheral arterial disease (PAD), and coronary artery disease (CAD) are common pathologic lesions; their interrelationship is, however, unclear. We studied concomitant multiple atherosclerotic lesions in patients with CAD to understand their prevalence and relations. A cross-sectional analysis was performed on data from consecutive patients who underwent nonemergent coronary angiography. Simultaneous carotid and renal artery Doppler studies and ankle-brachial systolic pressure measurements were reviewed to diagnose concomitant lesions and their severity. The study included 1,734 patients (aged 71 ± 9 years; 70% men), with prevalences of CAS, RAS, lower extremity PAD, and CAD of 6%, 7%, 13%, and 72%, respectively. In patients with CAD (n = 1,253), the prevalences of CAS, RAS, and lower extremity PAD were 7%, 9%, and 16%, respectively; 24% CAD patients had ≥1 additional atherosclerotic lesion. Significant interactions among the prevalences of these lesions were found. In addition, the extent of CAD and the prevalences of CAS, RAS, and lower extremity PAD were significantly correlated. Multivariate analysis supported these relationships. In conclusion, the prevalences of CAS, RAS, lower extremity PAD, and CAD were strongly interrelated in the study population; CAD severity was related to that of other atherosclerotic lesions. Additional systematic screening of other concomitant atherosclerotic lesions is recommended, especially in CAD patients having multivessel disease, left main disease, and/or already diagnosed with other concomitant atherosclerotic lesions.

Hyperreninemic hypertension following presumed abdominal trauma

An 18-year-old previously normotensive man was referred to a hypertension unit with blood pressure readings of 140-150/100-110 mmHg. Renal ultrasound had shown a right renal subcapsular fluid collection and an abdominal computed tomography scan had revealed a large cystic lesion surrounding the right kidney with a thick wall and irregular peripheral calcification consistent with a long-standing traumatic perinephric hematoma. Physical examination, renal artery duplex ultrasonography, magnetic resonance imaging of the abdomen, isotopic renography with technetium-99m diethylenetriamine pentaacetic acid, and a renal venous renin ratio study. Hyperreninemic hypertension as a result of presumed abdominal trauma. Removal of the affected kidney.

Predictors of Diagnostic Success With Renal Artery Duplex Ultrasonography

Renal artery duplex ultrasonography (RA-DUS) is commonly used for the evaluation and follow-up of renal artery atherosclerotic disease. In a complete study, renal artery flow is evaluated from the vessel origin to the intraparenchymal branches. The quality of RA-DUS is in part technologist-dependent, but many factors may affect the ability to complete a diagnostic examination. This study evaluated the clinical and technical factors that predict the ability to obtain a complete RA-DUS examination. A prospective evaluation of all patients undergoing RA-DUS between July 2008 and February 2009 was performed. Factors such as patient age, gender, body mass index, technologists' years of experience, patient care setting (inpatient vs. outpatient), bedside examination, smoking before the examination, fasting status, and recent abdominal surgery were all recorded. Multivariate logistic regression analysis was performed. A p value of ≤ 0.05 was considered significant. During the study period, 250 patients underwent RA-DUS (mean age: 59.9 ± 17.8 years, 57% [143] female). A total of 87 (35%) examinations were incomplete. This included nondiagnostic examinations which did not exhibit any segment of the renal artery. Factors that were associated with an incomplete examination included technologists' years of experience (OR = 0.92, p = 0.042), bedside examination (OR = 4.17, p = 0.016), and recent abdominal surgery (OR = 3.45, p = 0.047). Body mass index, fasting status, and smoking before the examination did not affect the ability to obtain a complete study. One-third of the RA-DUS studies were classified as incomplete by the strict criteria used in this prospective study. An experienced ultrasound technologist is more likely to obtain a complete RA-DUS examination. Recent abdominal surgery and bedside examinations were predictive of a limited examination as well. Vascular laboratories should consider these factors when scheduling examinations so as to obtain complete RA-DUS studies, as well as improve the cost-effectiveness of resource utilization.

Macroaneurysm in a Renal Fibromuscular Dysplasia

A 25-year-old woman presented with a headache. The general practitioner diagnosed hypertension 18 months previously, no regular antihypertensive medication was started, and the patient took bisoprolol as needed. There was no family history of hypertension. Physical examination revealed a blood pressure of 195/115 mm Hg in both arms. Renal function tests and serum potassium was normal. A renal ultrasound showed a slightly smaller left kidney. Renal artery duplex ultrasonography showed signs of a renal artery stenosis (narrowing and an aliasing effect in the left renal artery (Figure 1A arrow) with a peak velocity of …

Adventitial Fibromuscular Dysplasia of the Renal Artery

A 19-year-old healthy woman presented with new onset of severe migrainous headache. She did not take medications or use illicit drugs. There was no personal or family history of hypertension. Physical examination revealed a blood pressure of 220/130 mm Hg in both arms. There was no fourth heart sound. She had full and symmetric pulses in the upper and lower extremities with no radial/femoral delay. There were no carotid, subclavian, or abdominal bruits. Fundoscopic examination revealed normal retinal arteries without hypertensive retinopathy. Renal function and serum potassium were normal. Renal artery duplex ultrasonography revealed elevated peak systolic and end-diastolic velocities in the mid to distal portion of the right renal artery, consistent with severe right renal artery stenosis. The left renal artery was normal. The right kidney measured 8.8 cm with atrophy of the right cortical margin. The left kidney was 11.5 cm. There were normal renal resistive indexes …

Diagnosis and management of atherosclerotic renal artery stenosis: improving patient selection and outcomes

Renal artery stenosis (RAS) is common among patients with atherosclerosis, and is found in 20-30% of individuals who undergo diagnostic cardiac catheterization. Renal artery duplex ultrasonography is the diagnostic procedure of choice for screening outpatients for RAS. Percutaneous renal artery stent placement is the preferred method of revascularization for hemodynamically significant RAS, and is favored over balloon angioplasty alone. Stent placement carries a class I recommendation for atherosclerotic RAS according to ACC and AHA guidelines. Discordance exists between the very high (>95%) procedural success rate and the moderate (60-70%) clinical response rate after renal stent placement, which is likely to be a result of poor selection of patients, inadequate angiographic assessment of lesion severity, and the presence of renal parencyhmal disease. Physiologic lesion assessment using translesional pressure gradients, and measurements of biomarkers (e.g. brain natriuretic peptide), or both, could enhance the selection of patients and improve clinical response rates. Long-term patency rates for renal stenting are excellent, with 5-year secondary patency rates greater than 90%. This Review will outline the clinical problem of atherosclerotic RAS and its diagnosis, and will critically assess treatment options and strategies to improve patients' outcomes.

Renal artery stenting with noninvasive duplex ultrasound follow‐up: 3‐year results from the RENAISSANCE renal stent trial

The multicenter, single-arm RENAISSANCE trial evaluated outcomes in patients with progressive atherosclerotic renal artery stenosis (ARAS) treated with the Express Renal Premounted Stent System (Boston Scientific, Natick, MA). Renal artery stenting may prevent the morbidity and mortality of surgical revascularization and high restenosis rates of percutaneous renal angioplasty (PTRA). Renal artery duplex ultrasonography (DUS) offers an alternative to traditional invasive poststenting angiographic surveillance, though concordance with angiography for in-stent restenosis has yet to be validated independently. RENAISSANCE enrolled 100 patients (117 lesions) with de novo or restenotic ostial atherosclerotic lesions <or=15 mm long in vessels >or=4.0 and <or=7.0 mm diameter with diameter stenosis >or=70%. The primary endpoint, 9-month binary restenosis, was compared to an objective performance criterion (OPC) of 40% for published PTRA results. Follow-up was conducted through 3 years. Technical and procedural success was both 99%. Follow-up angiography, triggered clinically or by ultrasonography, revealed 21.3% binary restenosis at 9 months, which was superior to the OPC (P < 0.0001). Concordance between ultrasonography and angiography for detection of binary restenosis at 9 months was 87%. Peak systolic velocity and renal-to-aortic ratio were both significantly improved compared to baseline at 9 months and 2 years. The major adverse event (defined as device- or procedure-related death, target lesion revascularization or significant embolic event) rate was 10.5% at 9 months and 20.9% at 3 years. RENAISSANCE demonstrates that renal artery stenting is superior to the prespecified OPC at 9 months, and also shows that DUS can accurately identify in-stent restenosis.

Atherosclerotic renal artery stenosis and renovascular hypertension: clinical diagnosis and indications for revascularization.

Atherosclerotic renal artery stenosis (RAS) is relatively common and often associated with reversible hypertension, progressive renal insufficiency, and/or coronary-independent pulmonary edema. Not all RAS is associated with renovascular hypertension. Historical and physical findings may suggest renovascular hypertension and warrant investigation for RAS. Noninvasive diagnostic imaging options include renal artery duplex ultrasonography, magnetic resonance angiography, computed tomographic angiography, and CO2 angiography, with each method having its own advantages and limitations. Functional tests of renal flow, which characterize RAS significance, include captopril-stimulated plasma renin activity and captopril renography. To date, no single approach has shown clear superiority either in diagnosis or identification of patients most likely to benefit from revascularization. Revascularization of RAS is recommended for severe/drug-refractory hypertension, preservation of renal function, recurrent flash pulmonary edema, or recurrent severe heart failure. Intervention response is variable, but the ongoing Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial, comparing medical therapy with and without stenting, should provide management guidance.

Renal Artery Duplex Ultrasonography as a Screening and Surveillance Tool to Detect Renal Artery Stenosis

Digital subtraction angiography quantitative vessel analysis (QVA) to assess percent renal arterial stenosis (RAS) is the reference standard. Quantitative vessel analysis is not ideal for screening purposes. Renal artery duplex ultrasonography (RADUS) is a noninvasive method to screen for RAS using well-known parameters. We investigated the direct correlation between several RADUS parameters and QVA to evaluate the acceptability of RADUS as a RAS screening and surveillance tool. We performed a multicenter retrospective study. Stenoses were evaluated in all patients with arteriograms and RADUS examinations within 30 days of each other in the span of 1 year. Percent stenosis of each stenotic renal artery segment was calculated digitally with QVA and correlated with the corresponding peak systolic velocity (PSV) and renal-aortic ratio (RAR) obtained with RADUS. Descriptive statistics and receiver operating characteristic curves were calculated. Correlation of percent stenosis, PSV, and RAR was performed. Sensitivity, specificity, and accuracy of diagnostic cut points for each RADUS parameter were calculated. Sixty-seven renal arteries were included. Thirty-three arteries had less than 60% stenosis; 34 had stenosis of 60% or greater. The mean values were PSV, 272.791 cm/s; RAR, 3.716; and angiographic percent stenosis, 51.731%. Receiver operating characteristic curves showed higher accuracy for RAR with stenoses of 60% or greater versus PSV. Renal artery duplex ultrasonographic parameters for 60% or greater RAS correlate well with QVA. For detecting stenosis of 60% or greater, RAR is the most accurate parameter at a threshold of 2.5. Renal-aortic ratio is more accurate than PSV. Peak systolic velocity may be a useful RADUS alternative parameter for hemodynamically important stenoses in the setting of aortic disease when aortic velocities are less than 40 or greater than 100 cm/s.

Renovascular hypertension

Renal artery disease is the most common cause of potentially curable secondary hypertension, with atherosclerosis as the major cause of renal artery stenosis. Fibromuscular dysplasia is a less common cause of renal artery stenosis and is most frequently observed in premenopausal women. Renal artery stenosis is likely to be underappreciated and is more common in patients with other vascular disease (e.g., coronary or peripheral arterial disease). The diagnosis of renal artery stenosis requires a high clinical index of suspicion as well as an appropriate imaging strategy, with currently effective diagnostic modalities including magnetic resonance imaging, computed tomography and renal artery duplex ultrasonography. The current treatment of choice for atherosclerotic renal artery stenosis is balloon angioplasty and secondary stenting, whereas angioplasty alone is the treatment for renal artery stenosis secondary to fibromuscular dysplasia. Expected outcomes following revascularization include improved blood pressure control and possibly renal preservation. Ongoing studies will hopefully identify patient characteristics that will achieve the most benefit from percutaneous revascularization as well as the impact of percutaneous revascularization with drug-eluting stents and embolic protection devices.