High-grade Renal Artery Stenosis Research Articles

Managing acute presentations of atheromatous renal artery stenosis

BackgroundAtherosclerotic renovascular disease (ARVD) often follows an asymptomatic chronic course which may be undetected for many years. However, there are certain critical acute presentations associated with ARVD and these require a high index of suspicion for underlying high-grade RAS (renal artery stenosis) to improve patient outcomes. These acute presentations, which include decompensated heart failure syndromes, accelerated hypertension, rapidly declining renal function, and acute kidney injury (AKI), are usually associated with bilateral high-grade RAS (> 70% stenosis), or high-grade RAS in a solitary functioning kidney in which case the contralateral kidney is supplied by a vessel demonstrating renal artery occlusion (RAO). These presentations are typically underrepresented in large, randomized control trials which to date have been largely negative in terms of the conferred benefit of revascularization.Case presentationHere we describe 9 individual patients with 3 classical presentations including accelerated phase hypertension, heart failure syndromes, AKI and a fourth category of patients who suffered recurrent presentations. We describe their response to renal revascularization. The predominant presentation was that consistent with ischaemic nephropathy all of whom had a positive outcome with revascularization.ConclusionA high index of suspicion is required for the diagnosis of RAS in these instances so that timely revascularization can be undertaken to restore or preserve renal function and reduce the incidence of hospital admissions for heart failure syndromes.

Treatment of Severe Renal Artery Stenosis with Acute Kidney Injury Requiring Hemodialysis by Percutaneous Transluminal Renal Angioplasty and Stent Implantation

PurposeTo evaluate the outcomes of percutaneous transluminal renal angioplasty with stent implantation (PTRAS) among patients with renal artery stenosis (RAS) who become dialysis-dependent due to acute deterioration of renal function. Materials and MethodsThis was a single-center retrospective cohort study of all PTRAS procedures performed from 2003 to 2019 in a referral hospital. A total of 109 procedures were performed in 92 patients. Eleven patients (12%) presented with anuric acute kidney injury (AKI) secondary to high-grade RAS (defined as intraluminal stenosis above 70% per angiography) and underwent PTRAS after starting hemodialysis. Data collected included demographic parameters, medical background, creatinine, blood pressure, indication for intervention, procedure characteristics, adverse events, and long-term data including dialysis treatment and mortality. Among the dialysis-dependent AKI group, outcome measures were defined based on the postprocedural improvement in kidney function and discontinuation of dialysis. ResultsFollowing PTRAS, 8 of 11 patients (73%) demonstrated improved kidney function and were able to discontinue dialysis. The median time on dialysis was 18 days (range, 2–35 days) before PTRAS and 4.5 days (range, 1–24 days) to recovery of kidney function after the time of intervention. ConclusionsPatients with atherosclerotic RAS who develop RAS-related AKI may benefit from PTRAS even after several weeks of anuria and dialysis dependence.

CRT-200.17 Impact of Race on Clinical Outcomes After Stent Revascularization for High-Grade Renal Artery Stenosis: A Single-Center Experience

The management of atherosclerotic renal artery stenosis can be challenging. Whether race has an impact on outcomes after revascularization is unknown. We report a single-center experience with patients with high-grade stenosis Patients with high-grade renal artery stenosis (a reduction in lumen

Diagnostic value of contrast-enhanced sonography and digital subtraction angiography for renal artery stenosis

Objective: To evaluate the diagnostic value of contrast-enhanced ultrasound (CEUS) and digital subtraction angiography (DSA) for renal artery stenosis (RAS). Methods: Fifty-seven hypertensive patients suspected for RAS admitted in Beijing Hospital from September 2017 to August 2018 were enrolled. All 114 renal arteries were assessed by CEUS and DSA. RAS was subdivided into low-(30%-50%), moderate-(50%-69%) and high-grade (70%-99%) subgroups. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were compared between CEUS and DSA results. Results: Fifty-seven hypertensive patients (31 males, mean age 57.1 years) involving 114 renal arteries were included. Overall, DSA identified RAS in 71(62.3%) renal arteries, mild RAS, 34(29.8%); moderate RAS, 23(20.2%); severe RAS, 14(12.3%). With CEUS, the sensitivity, specificity, accuracy, PPV and NPV for detecting mild-grade RAS were 85.3%, 97.3%, 91.5%, 96.7% and 87.8%; for detecting moderate-grade RAS were 82.6%, 97.9%, 92.9%, 95.0% and 92.2%; for detecting high-grade RAS were 85.7%, 98.2%, 95.8%, 92.3% and 96.5%. The measure of agreement kappa was 0.92 between CEUS and DSA. Conclusion: CEUS is a safe and accurate method for the diagnosis and severity classification of RAS, especially those with kidney injury.

Imaging of visceral vessels

Visceral vessel processes are primarily or secondarily included in amultitude of clinical abdominal symptoms, with which the specialist in internal medicine is confronted. The spectrum ranges from more sharply outlined manifestations, such as chronic ischemic bowel disease up to dysfunctional disturbances of blood pressure regulation, such as high-grade renal artery stenosis. Sometimes diseases with prognostic implications, such as arterial aneurysms, are revealed as incidental findings. As a rule the B‑mode and duplex ultrasound can often be complemented by computed tomography (CT) and magnetic resonance imaging (MRI), as in aneurysms or portal vein thrombosis or the indications for subsequent digital subtraction angiography (DSA) and catheter-based therapy can be directly obtained from duplex and Doppler ultrasound. The present review article focuses on the use of these methods in the most important diseases, with the exception of acute abdomen because this requires further detailed etiological and diagnostic systematization.

Renal artery stenosis precipitates hyponatremic hypertensive syndrome and posterior reversible leukoencephalopathy.

Hyponatremic hypertensive syndrome (HHS) is an uncommon disorder usually encountered in the adult population with unilateral renal artery stenosis and is under-recognized in the pediatric population. A 19-month-old male presented with new-onset status epilepticus associated with neurological sequelae, and hypertension to a high of 248/150 mmHg. Lab work revealed significant hyponatremia, elevated peripheral renin activity, and increase in aldosterone and ADH levels. A diagnosis of HHS was made. Initial analysis revealed a high-grade proximal renal artery stenosis by magnetic resonance imaging (MRI) and angiogram. Electroencephalogram and an MRI of the brain demonstrated characteristic abnormalities of the left temporal-parietal regions consistent with posterior reversible leukoencephalopathy syndrome (PRES). The patient responded to right renal artery balloon dilation and stent placement. Since intervention and close blood pressure control with Amlodipine, the patient has been free of seizures and is neurologically intact. We report a case of malignant hypertension in a 19-month-old male secondary to renal artery stenosis with associated HHS and PRES. Prognosis of PRES in children with renal disease is excellent. Prompt intervention may offer near complete resolution of physiologic and symptomatic effects of HHS and PRES due to high-grade renal artery stenosis. This report was written with parental consent for de-identified case presentation and radiographs for the educational benefit of other medical professionals.

Hibernating kidney: CEUS proofing kidney viability after renal artery occlusion in EVAR

A 72-year old male patient underwent endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm, developed acute renal failure with dialysis dependency and was transferred to our unit. Colour coded duplex sonography showed high-grade renal artery stenosis of the right renal artery with an ischemic shrunken kidney. The left renal artery could not be visualized, arterial signals in the periphery were absent. Contrast enhanced ultrasound, however, disclosed slowed, but complete perfusion of the renal parenchyma without signs of infarction. Angiography proofed renal artery stenosis of the right kidney and occlusion of the left renal artery, revascularition could not be performed. Therefore, operative salvage of the left kidney with a splenorenal anastomosis was performed with resolution of renal failure. Conclusion: CEUS proofed the viability of an nonfunctioning kidney after renal artery occlusion, perfused with subfiltration perfusion pressure presumably from collateral vessels, suggesting a good chance of revascularisation.

Nierenversagen und wiederholte Episoden eines blitzartig auftretenden Lungenödems bei einer 70-jährigen Patientin - Fall 5/2013

We report on a patient presenting with renal failure who developed mutliple episodes of flash pulmonary edema. Volume retention due to ischemic nephropathy was found to be the cause. She was diagnosed to have a high grade renal artery stenosis in a functional solitary kidney and underwent percutaneous angioplasty. After being anuric and dialysis-dependent, she regained her kidney function leading to resolution of the volume retention and could be weaned from dialysis. Ischemic nephropathy is often accompanied by recurrent episodes of flash pulmonary edema and responds well to an interventional treatment.

Pickering syndrome: high-risk stenting of a renal artery stenosis in a multimorbid patient presenting with progressive congestive heart failure

Acute chest pain and progressive dyspnea led to the admission of an 83-year-old female patient with known severely impaired left ventricular (LV) function and secondary mitral regurgitation II due to dilated cardiomyopathy (DCM). Recurrent decompensations had led to cardiac resynchronization therapy via defibrillator (CRTD) implantation. Present cardiovascular risk stratification revealed metabolic syndrome (obesity, diabetes mellitus type 2, arterial hypertension and hyperlipoproteinemia) complicated by previous stroke, whereas relevant coronary artery disease had been excluded years before. Moreover, recurrent exacerbating obstructive lung disease (COLD, GOLD III) was reported and advanced renal failure was documented [K/DOQI III, serum creatinine 2.2 mg/dL, urea 96 mg/dL, glomerular filtration rate (GFR, MDRD) 23 mL/min]. Initial clinical examination revealed wheezing over both lungs and mild edema of the lower limbs. There was sinus rhythm at a normal heart rate and bothsided blood pressure of 220/100 mmHg. Chest pain did not completely diminish, whereas myocardial infarction was ruled out using highly sensitive troponin T assay. The patient’s antihypertensive medication included seven substances with several second-line antihypertensives, all at high dose. Under additional intravenous (i.v.) nitrates, blood pressure remained merely controllable. With the addition of an oral central a-2 agonist and an oral reninreceptor antagonist, i.v. nitrates could be weaned (Table 1). In view of severely reduced glomerular filtration rate, the patient was refused to be treated with mineralocorticoidreceptor antagonist (MRA) as spironolactone or eplerenone, but left with sequential nephron blockade [1]. Coronary angiography demonstrated a high-grade stenosis of the left anterior descending coronary artery, contributing to recurrent angina pectoris. Percutaneous coronary intervention (PCI) was performed immediately. Post-PCI, we decided to angiographically search for underlying renal artery stenosis (RAS) in a hypertensive patient with continuously decreasing renal function and known coronary atherosclerosis. We demonstrated a highgrade RAS on the left (Fig. 1) and a rudimental renal artery on the right side. Further diagnostic workup including kidney ultrasound revealed a right-sided renal hypoplasia with no measurable resistance index (RI) and a normal appearing left kidney with a moderately reduced RI of 0.85. Thus, renal artery revascularization was considered, but defined as an ultima ratio after having exhausted all medical options. Under extended medical therapy (Table 1), the patient recurrently presented with blood pressures of up to 190/100 mmHg with accompanying angina and dyspnea due to flash pulmonary edema on days 4 and 7. Finally, stenting of the left renal artery was performed (Fig. 1). Hemodynamically relevant RAS (C70 % diameter stenosis) is one potential cause of secondary hypertension, also leading to impairment of renal function. Its diagnosis and its causal connection to hypertension and renal failure can be ambiguous. There are two underlying pathologies: 95 % of RAS is caused by atherosclerosis typically found at the proximal or ostial vessel. Fibromuscular dysplasia showing a string of beat pattern of the mid and/or distal renal artery is less T. Demming N. Frey C. Langer (&) Klinik fur Kardiologie und Angiologie, Universitares Gefaszentrum Nord, Universitatsklinikum Schleswig–Holstein, Campus Kiel, Christian-Albrechts Universitat Kiel, Schittenhelmstr. 12, 24105 Kiel, Germany e-mail: christoph.langer@uksh.de

ASSESSMENT OF RENAL ARTERY STENOSIS USING FRACTIONAL FLOW RESERVE - CORRELATION WITH ANGIOGRAPHY AND ULTRASONOGRAPHY: PP.30.197

Objective: The aim of the study was to investigate fractional flow reserve and translesional pressure gradient in moderate to high grade renal artery stenosis (RAS) with respect to angiographic measurements and Doppler-ultrasonography. Design and Method: 43 hypertensive patients (22F, 21 M, mean age 58.5 years) with at least moderate (more than 50%) RAS were investigated. Using the pressure wire, translesional systolic pressure gradient (TSPG), resting Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic renal fractional flow reserve (rFFR) - after administration of 30 mg intrarenal papaverine- were evaluated. Quantitative angiographic analysis of stenosis severity was performed including minimal lumen diameter (MLD) and percent diameter stenosis (DS) assessment. Renal:aortic ratio (RAR) and resistive index were obtained in Doppler-duplex ultrasonography. The predictive value of different variables was calculated using Receiver-operating characteristics (ROC) curves. Results: Mean Pd/Pa ratio was 0.85+/−0.12 and decreased to 0.79+/−0.13 after papaverine administration. Both Pd/Pa ratio and rFFR strongly correlated with MLD (r = 0.56, p < 0.001 and r = 0.63, p < 0.001) and DS (r = −0.52, p < 0.01 and r = −0.57,p < 0.001). Patients with Pd/Pa ratio < 0.9 had non-significantly increased RAR (3.43 vs 3.03,p = 0,11) as compared to those with normal Pd/Pa ratio. Patients with rFFR<0.8 had non-significantly increased RAR (3.44 vs 3.02,p = 0.09) in comparison to patients with normal rFFR. In assessment of more than 50% RAS (in QCA) the areas under the curves for Pd/Pa and rFFR were 0.913 and 0.920 respectively (p < 0.001 and p <0.001). The sensitivity and specifity for Pd/Pa ratio<0.9 were 100% and 62,5% and for rFFR<0.8 100% and 59,4% respectively. The most predictive cut-off values for RAS were: <0.92 for Pd/Pa ratio (100% specificity and 75% sensitivity) and <0.83 for rFFR (100% specificity and 75% sensitivity). Conclusions: Mean Pd/Pa ratio and renal fractional flow reserve correlated strongly with angiographic data and in a less pronounced manner with parameters reflecting intrarenal blood flow. The best accuracy cut-off points for renal artery stenosis predicting were <0.92 and <0.83 respectively.

Predictive value of duplex ultrasound for restenosis after renal artery stenting

Factors predicting renal function and recurrent stenosis following percutaneous renal revascularization are poorly identified. The predictive value of hemodynamic duplex ultrasound (DUS) parameters was evaluated. In a prospective observational study patients undergoing stenting of renal artery stenosis (RAS) were included. Renal resistance index (RI) and peak systolic velocity (PSV) were measured at baseline, one day, and six months after intervention. At 6-months follow-up 16 (16.8%) restenosis of 105 treated renal arteries were detected. Baseline RI was 0.69 +/- 0.12 and increased significantly to 0.72 +/- 0.09 after 6 months (p < 0.0001), however, RI did not predict restenosis. PSV at baseline and age were independent predictors for increased RI at 6 months (p = 0.0078 and p = 0.0019). Diabetics had a significant higher RI before revascularization (0.74 +/- 0.08) than non-diabetics (0.68 +/- 0.12, p = 0.04). PSV after stenting was higher in patients with restenosis (1.4 +/- 0.4 m/sec vs. 1.0 +/- 0.3 m/sec, p = 0.002) and was an independent predictor for restenosis. Increased PSV within the stent one day after the procedure is predictive for restenosis. Patients with high grade RAS and older patients have a worse outcome. DUS is recommended to detect patients at risk for restenosis after percutaneous renal revascularization.

Acute Bilateral Renal Vein Thrombosis

Acute Bilateral Renal Vein Thrombosis

SNP rs198389 (T‑381 C) polymorphism in the B‑type natriuretic peptide gene promoter in patients with atherosclerotic renovascular hypertension

Renovascular hypertension caused by renal artery stenosis (RAS) accounts for 3-5% of all cases of hypertension. The aim of the study was to determine the association between SNP rs198389 (T-381 C) polymorphism in the B-type natriuretic peptide promoter (BNP) gene and the degree of RAS in patients with atherosclerotic renovascular hypertension. Thirty-six patients scheduled for invasive diagnostic evaluation of atherosclerotic renovascular hypertension were enrolled in the study. Arteriography was performed through a femoral artery access. In order to identify SNP rs198389 (T-381 C) polymorphism in the BNP gene genotyping was performed using genomic DNA isolated from peripheral blood leukocytes. Amplified by polymerase chain reaction and purified product was used to minisequencing. Capillary electrophoresis was applied to separate and detect minisequencing products. The analysis enabled to discriminate TC heterozygotes, TT homozygotes, and CC homozygotes at position 381 of the BNP gene promoter. Patients homozygous for C allele occurred more frequently in patients with high-grade RAS in comparison with the moderate and mild stenosis groups. TT homozygotes were observed more frequently in mild stenosis patients compared to the moderate and high-grade stenosis groups. None of the patients who had mild RAS was homozygous for C allele and none of the patients who had severe RAS was homozygous for T allele. We demonstrated the association between SNP rs198389 (T-381 C) polymorphism in the BNP gene promoter and the degree of RAS in patients with atherosclerotic renovascular hypertension. It appears that subjects homozygous for C allele at position 381 of the BNP precursor gene promoter are more prone to develop atherosclerotic lesions in renal arteries.

Screening for renal artery stenosis in patients with aorticoiliac occlusive disease

The prevalence of atherosclerotic renal artery disease has increased with improved life expectancy. Because renal artery stenosis is a potentially correctable cause of hypertension and ischemic nephropathy, early identification of this entity may lead to proper hypertension control and improved renal function and survival. The aim of this study was to determine the prevalence and patterns of subclinical renal artery stenosis in patients with aorticoiliac atherosclerosis. The abdominal angiographies of 44 patients with high-grade aorticoiliac occlusive disease (> 70% stenosis) were reviewed for evidence of renal artery stenosis. This was compared to a group of 20 patients with mild-to-moderate aorticoiliac disease (< 70% stenosis). These patients had no history of renal artery disease or renal failure. In patients with high-grade aorticoiliac occlusive disease, renal artery stenosis was found in 25 patients (56.8%); 13 with unilateral (29.5%) and 12 (27.3%) with bilateral involvement. A hemodynamically significant stenosis (> 50%) was found in 11 patients (25%), one of whom had bilateral stenosis (2.3%). High-grade renal artery stenosis (> 70%) or complete arterial occlusion was noted on seven sides (7.9%). The most common sites of stenosis were the origin and first centimeter of the renal artery. In patients with mild-to-moderate aorticoiliac disease, renal artery stenosis was found in two patients (10%). The present study revealed that subclinical renal artery disease may be present in more than half of the patients with high-grade aorticoiliac atherosclerosis highlighting the need for proper risk stratifications and screening programs. Based on our results, we suggest that examination of the renal arteries in these patients may be necessary in order to delay or prevent complications. Additionally, such information may have important therapeutic implications in planning reconstructive vascular surgeries or percutaneous angioplasties.

Renal Stenting for Incidentally Discovered Renal Artery Stenosis: Is There Any Outcome Benefit?

Conclusion: Stenting of incidentally discovered renal artery stenoses at the time of an angiogram performed for another indicated procedure results in minimal benefit compared with medical management alone. Summary: Significant renal artery stenosis is frequently encountered at the time of angiography performed for other forms of arterial disease. The authors performed a retrospective medical record review of patients undergoing renal arteriography during 4 years. They used catheterization reports to identify patient diagnosed with high-grade renal artery stenosis (>70%). Patients treated with renal artery angioplasty were identified, and baseline and postprocedural blood pressure, glomerular filtration rate, serum creatinine, and antihypertensive medication regimens were compared after 12 months of follow-up. During the 4-year period, 124 patients underwent renal arteriography with 78 (63%) diagnosed with high-grade renal artery stenosis. Renal artery stents were placed in 58 patients (74%). When compared with the patients with high-grade renal artery stenosis who received no intervention, the patients with renal artery stents had similar baseline characteristics with the exception of lower diastolic blood pressure (74 ± 11.2 vs 80 ± 14.2 mm Hg, P = .04) and a higher proportion of increased lipids (78% vs 55%, P = .05). Follow-up was available in 58 of the renal artery stented patients (66%). Postprocedural variables in patients with renal artery stents with 12-month follow-up indicated there was reduction in systolic blood pressure (153 ± 20.8 vs 136 ± 27.2, P = .01) and mean arterial pressure (103 ± 11.2 vs 95 ± 14 mm Hg, P = .04). Significant reductions in systolic mean arterial and diastolic blood pressure were, however, only noted in the patients who also had an increase in the number of antihypertensive medications. There were no differences in renal insufficiency detected. Comment: This is a retrospective study with incomplete data. Nevertheless, it is certainly not a testimonial to the efficacy of renal artery stents in patients with unsuspected renal artery stenosis. The only parameter that improved in the stented patients was blood pressure, and that only improved if there was an increase in antihypertensive medications. The data do not support routine practice of renal angioplasty and stenting for incidentally discovered lesions. Clearly, the management of incidentally discovered renal artery stenosis remains controversial.

Diffusion Tensor Imaging of the Kidney With Parallel Imaging: Initial Clinical Experience

To evaluate the clinical feasibility of diffusion tensor imaging (DTI) of the kidney in volunteers and patients with renal diseases. Ten volunteers and 22 patients (mean age, 56 +/- 14.3) with renal masses and renal artery stenosis underwent breath-hold coronal fat-saturated echo-planar DTI (as provided by the manufacturer, 6 diffusion directions, diffusion weightings b = 0 and 300 s/mm2, repetition time 730 ms/echo time 72 ms; 5 slices; slice thickness, 6 mm; inplane resolution, 2.1 x 2.1 mm2; acquisition time, 26 seconds) of the kidneys at 1.5 T (MAGNETOM Avanto, Siemens Medical Solutions, Erlangen, Germany). The parallel imaging technique, generalized autocalibrating partially parallel acquisitions with an acceleration factor 2, was applied. Using the commercially available Syngo DTI task card software, regions of interests were placed in the cortex, medulla, and in renal masses if present. Fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were determined, and tractography was used to visualize the renal diffusion properties. Statistical analysis was performed using the Wilcoxon signed-rank sum test and paired t tests. In all volunteers, FA was significantly (P < 0.01) higher in the medulla (0.36 +/- 0.03) than in the cortex (0.21 +/- 0.02), whereas the ADC was significantly (P < 0.01) higher in the cortex (2.43 +/- 0.19) than in the medulla (2.16 +/- 0.22). Tractography typically revealed a radial preferred direction of medullary diffusion basically reflecting medullary flow.FA/ADC of simple renal cysts (n = 8) was 0.14 +/- 0.05/2.86 +/- 0.15. Renal cell carcinoma (n = 10) showed a wide FA range from 0.11 to 0.56. Using tractography, the structural organization of renal cell carcinoma such as pseudocapsules could be visualized.In 1 patient with unilateral high-grade renal artery stenosis, the cortical ADC of the affected kidney was lower than on the contralateral side (1.77/2.27) and the FA was increased (0.33/0.18). The FA of the medulla was increased (0.70/0.41) and the ADC decreased (1.43/1.90). Using parallel imaging, DTI measurements of the kidneys are feasible within a single breath-hold with good discrimination between cortex and medulla. Parallel imaging allows more slices and a superior resolution. DTI measurements of the kidney allows visualization of medullary flow, in pathology ADC and FA were altered. Further investigations will be required to evaluate the role of DTI for studying and monitoring renal ultrastructure.

Renal Stenting for Incidentally Discovered Renal Artery Stenosis: Is There any Outcome Benefit?

We evaluated whether there was a clinical outcome benefit in patients incidentally discovered to have high-grade renal artery stenosis (RAS) and treated with percutaneous transluminal renal angioplasty and stenting (PTRAS) at the time of angiogram for another indicated procedure. A retrospective chart review was performed on all patients undergoing renal arteriography over 4 years at our academic tertiary-care referral center. Review of catheterization reports was used to identify patients diagnosed with high-grade RAS (reduction of > or =70% luminal diameter by arteriogram). Patients treated with PTRAS were identified. Baseline and postprocedure blood pressure (BP, an average of at least three independent measurements), glomerular filtration rate, serum creatinine, and antihypertensive medication regimen were compared for 12 months of follow-up. Over 4 years, 124 patients underwent renal arteriography and 78 (63%) were diagnosed with high-grade RAS. Fifty-eight patients (74% of those with high-grade RAS) received PTRAS. Patients treated with PTRAS had similar baseline characteristics to those with high-grade RAS with no intervention, with the exception of lower diastolic BP (DBP; 74 +/- 11.2 vs. 80 +/- 14.2 mm Hg, p = 0.04) and a higher proportion of hyperlipidemia (78 vs. 55%, p = 0.05). Thirty-eight out of 58 PTRAS patients (66%) received sufficient follow-up to assess outcomes. When baseline and postprocedure variables were compared in PTRAS patients with 12-month follow-up, there was a reduction in systolic BP (SBP, 153 +/- 20.8 vs. 136 +/- 27.2 mm Hg, p = 0.01) and mean arterial pressure (MAP, 103 +/- 11.2 vs. 95 +/- 14 mm Hg, p = 0.04). When these patients were stratified by those with an increase, decrease, or no change in postprocedure antihypertensive medications, significant reductions in SBP, MAP, and DBP were noted only in the patient population that also had an increase in the number of antihypertensive medications. No differences in renal insufficiency were detected. Patients with high-grade RAS incidentally discovered during arteriography performed for extrarenal disease and treated with PTRAS have a modest reduction in BP, which is significant only in those patients with an increased number of antihypertensive medications postprocedure. Caution must be taken in stenting patients with incidental RAS as outcome benefit may be minimal when compared to medical management only.

Traitement endovasculaire d’un anévrisme et d’une sténose de l’artère rénale secondaires à une dysplasie fibromusculaire

Limited data are available regarding the optimal management of renal artery stenosis (RAS) with a coexisting renal artery aneurysm. We present a case of high-grade RAS treated successfully with a stent-graft deployment resulting in the exclusion of an associated aneurysm. This therapeutic approach induced the sustained normalization of the blood pressure without antihypertensive medication and the correction of biochemical abnormalities secondary to the RAS.

Best Duplex-Sonographic Criteria for the Assessment of Renal Artery Stenosis - Correlation with Intra- Arterial Pressure Gradient

Colour coded duplex sonography (DS) is widely used for the assessment of renal artery stenosis (RAS). Different criteria have been specified for the detection of significant RAS. The aim of our study was to compare routinely used DS criteria, both with intra-arterial pressure gradients and arteriographic degree of stenosis, and to validate different cut-off points of these DS criteria for the assessment of haemodynamically significant RAS. We retrospectively analysed forty-nine patients (median age 67 years, 29 male) with RAS documented by duplex sonography, referred for renal arterial subtraction arteriography and intra-arterial pressure measurement (93 renal arteries). DS measurement of peak systolic velocity (PSV) in the main renal artery, the renal/aortal velocity ratio (RAR) and the side-to-side differences of the intrarenal resistive indices (DeltaRI) were correlated to intra-arterial pressure measurements and arteriographic degree of stenosis. Receiver operating characteristics (ROC) were used to determine the best cut-off value of DS criteria. 39 (41 %) renal arteries had normal findings or non significant stenosis < 50 %, 23 (25 %) had a diameter reduction between 50 % and 69 %, and 31 (33 %) > or = 70 %. The systolic pressure gradient showed good correlation with the arteriographic degree of RAS (r = 0.77, p < 0.001) and the PSV measured by duplex sonography (r = 0.67, p < 0.001). Mean systolic pressure gradient was 24 mmHg at 50 % stenosis and 23 mmHg at PSV of 200 cm/sec. A PSV of > or = 200 cm/sec provided a sensitivity of 92 % and specificity of 81 % for detecting RAS of > or = 50 %. Similar results were found for RAR > or = 2.5 with a sensitivity of 92 % and specificity of 79 %. These cut-off values have a negative predictive value of 100 % for excluding high-grade RAS of > or = 70 %. A DeltaRI of > or =0.05 has low sensitivity of 31 %, but a high specificity of 97 % for detecting RAS of > or = 50 %. DS measurements and the severity of arteriographic diameter reduction correlate well with systolic pressure gradients. Clinically expedient DS criteria for detecting RAS of > or = 50 % are a PSV of > or = 200 cm/sec or a RAR of > or =2.5. These criteria allow reliable exclusion of severe RAS of > or = 70 %.

The management of renal artery atherosclerosis for renal salvage: Does stenting help?

The use of endovascular techniques to treat renal artery stenosis (RAS) has increased in recent years but remains controversial. The purpose of this study was to review the outcomes and durability of percutaneous transluminal angioplasty and stenting (PTA/S) for patients with RAS and decreasing renal function. Between 1999 and 2004, 125 consecutive patients underwent angiography and intervention for renal salvage and formed the basis of this study. Inclusion criteria for this study included serum creatinine greater than 1.5 mg/dL, ischemic nephropathy, and high-grade RAS perfusing a single functioning kidney. Patients undergoing PTA/S for renovascular hypertension or fibromuscular dysplasia or in conjunction with endovascular stent grafting for aneurysm repair were excluded. The original angiographic imaging was evaluated for lesion grade and parenchymal kidney size. All medical records and noninvasive testing were reviewed. Preoperative and postoperative patient data were standardized and analyzed by using chi(2) tests for nominal values and t tests for continuous variables. The Modification of Diet in Renal Disease equation was used to estimate glomerular filtration rate (GFR), and univariate analysis was performed. Preoperative variables included the presence of coronary artery disease (93%), diabetes (44%), tobacco use (48%), and hypercholesterolemia (70%). RAS was suspected on the basis of preoperative duplex imaging or magnetic resonance angiography. Aortography and PTA/S were performed in 125 patients (mean age, 71 years; 59% male) with a mean baseline creatinine level of 2.2 mg/dL. There were two mortalities (1.6%) in the 30-day postoperative period, but there was no case of acute renal loss. Blood pressure decreased after PTA/S (151/79 mm Hg before vs 139/72 mm Hg after 1 month; P < .03). For all patients, the estimated GFR went from 33 +/- 12 mL . min(-1) . 1.73 m(-2) (mean +/- SD) to 37 +/- 19 mL . min(-1) . 1.73 m(-2) at 6 months (P = .10). Sixty-seven percent of treated patients had improvement (>10% increase in GFR) or stabilization of renal function. A rapid decline in GFR before intervention was correlated with improvement after PTA/S. Responders after PTA/S had a 27% decrease in GFR before intervention (44 +/- 13 mL . min(-1) . 1.73 m(-2) to 32 +/- 13 mL . min(-1) . 1.73 m(-2); P < .001) with a negative to positive slope change in GFR values. Ten patients underwent reintervention for in-stent restenosis. Cases without improvement in GFR after PTA/S were associated with eventual dialysis need (P = .01; mean follow-up, 19 months). Survival at 3 years was 76%, and dialysis-free survival was 63% as estimated by Kaplan-Meier analyses. Renal artery stenoses causing renal dysfunction can be safely treated via endovascular means. Rapidly decreasing renal function is associated with the response to renal artery angioplasty/stenting and helps identify patients for renal salvage.