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Renal Artery Stenosis (renal + artery_stenosis)
Kinds of Renal Artery Stenosis Selected AbstractsRenal Artery Stenosis in Hypertension: What about the "Other" Alternative?JOURNAL OF CLINICAL HYPERTENSION, Issue 1 2001Raymond R. Townsend MD No abstract is available for this article. [source] Risk Factors and Long-Term Outcome of Transplant Renal Artery Stenosis in Adult Recipients After Treatment by Percutaneous Transluminal AngioplastyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2006V. Audard Transplant renal artery stenosis (TRAS) is a common complication of kidney transplantation but attempts to identify predisposing risk factors for TRAS have yielded conflicting results. In order to determine the predisposing factors for transplant (TRAS), we retrospectively reviewed the records of 29 renal allograft recipients with TRAS treated with percutaneous transluminal angioplasty (PTA). The TRAS group was compared with a case-control group of 58 patients. Predisposing factors for TRAS included CMV infection (41.4% vs. 12.1% p = 0.0018) and initial delayed graft function (DGF) (48.3% vs. 15.5% p = 0.0018), respectively in the TRAS and the control group. Acute rejection occurred more frequently in patients from the TRAS group (48.3%) compared with the control group (27.6%), although the difference was not significant (p = 0.06). In a multivariate analysis, only CMV infection (p = 0.005) and DGF (p = 0.009) appear to be significantly and independently associated with TRAS. The long-term graft survival was significantly higher in the control group, compared with the TRAS group (p = 0.03). Our study suggests that CMV infection and DGF are two reliable risk factors for TRAS. Despite treatment by PTA with primary successful results, TRAS significantly affects long-term graft outcome. [source] Estimation of the differential pressure at renal artery stenoses,MAGNETIC RESONANCE IN MEDICINE, Issue 5 2004Peter J. Yim Abstract Atherosclerotic disease of the renal artery can lead to reduction in arterial caliber and ultimately to conditions including renovascular hypertension. Renal artery stenosis is conventionally assessed, using angiography, according to the severity of the stenosis. However, the severity of a stenosis is not a reliable indicator of functional significance, or associated differential pressure, of a stenosis. A methodology is proposed for estimation of the renal artery differential pressure (RADP) from MR imaging. Realistic computational fluid dynamics (CFD) models are constructed from MR angiography (MRA) and phase-contrast (PC) MR. The CFD model is constructed in a semiautomated manner from the MR images using the Isosurface Deformable Model (IDM) for surface reconstruction and a Marching Front algorithm for construction of the volumetric CFD mesh. Validation of RADP estimation was performed in a realistic physical flow-through model. Under steady flow, the CFD estimate of the differential pressure across a stenosis in the physical flow-through model differed by an average of 5.5 mmHg from transducer measurements of the pressure differential, for differential pressures less than 60 mmHg. These results demonstrate that accurate estimates of differential pressure at stenoses may be possible based only on structural and flow images. Magn Reson Med 51:969,977, 2004. Published 2004 Wiley-Liss, Inc. [source] Usefulness of translesional pressure gradient and pharmacological provocation for the assessment of intermediate renal artery diseaseCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2006Noah J. Jones MD Abstract Objective: We sought to determine the hemodynamic significance of intermediate RAS by measuring translesional systolic pressure gradients (TSPG), using a pressure-sensing guidewire at baseline and after acetylcholine (ACh) induced hyperemia, following selective renal artery angiography. Background: Renal artery stenosis (RAS) is a cause of reversible hypertension and nephropathy. Stenting effectively relieves RAS, however improvement in blood pressure control or renal function is variable and unpredictable. Hemodynamic significance is usually present with RAS when diameter stenosis is >75%, but is less predictable in intermediate (30%,75%) RAS. Methods: Twenty-two patients (26 renal arteries) with uncontrolled hypertension underwent invasive hemodynamic assessment because of intermediate RAS, defined as radiocontrast angiographic diameter stenosis (DS) between 30% and 75% (quantitative DS was measured prospectively). Translesional pressure gradients were measured using a 0.014" pressure-sensing wire. Hyperemia was induced by administration of intrarenal ACh. Results: Visual and measured angiographic lesion severity did not correlate with TSPG either at baseline (visual DS, R2 = 0.091, P = 0.13; measured DS, R2 = 0.124, P = 0.07) or with hyperemia (visual DS, R2 = 0.057, P = 0.24; measured DS, R2 = 0.101, P = 0.12). Baseline and maximal hyperemic gradient did correlate (R2 = 0.567; P < 0.05). Pharmacological provocation produced a significant increase in TSPG (mean; baseline, 18 ± 21 vs. hyperemia, 34 ± 41 mm Hg; P < 0.05). A hemodynamically significant lesion (TSPG > 20 mm Hg) was found in 14/26 (54%) arteries (13 patients); 13 (60%) patients subsequently underwent renal artery stenting for hemodynamically significant RAS. At follow-up (at least 30 days), there was a significant decrease in systolic blood pressure (mean; 167 ± 24 vs. 134 ± 19 mm Hg; P < 0.001). Conclusions: Intrarenal administration of ACh induces hyperemia and can be used to unmask resistive renal artery lesions. Gradient measurement and induced hyperemia may be warranted in the invasive assessment of intermediate renal artery stenoses, rather than relying on stenosis severity alone. Further study is needed to determine whether translesional pressure gradients and pharmacological provocation predict clinical benefit after renal artery stenting. © 2006 Wiley-Liss, Inc. [source] Ischemic nephropathy in an elderly patientGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2 2008Satoshi Hoshide Congestive heart failure often occurs in patients with bilateral renal artery stenosis. Recently, Jacobson and Breyer, and Jacobson introduced the term "ischemic nephropathy", which implies critical bilateral involvement or global ischemia. Ischemic nephropathy is not only a cause of hypertension but also an important cause of end-stage renal disease. However, the aging kidney often show that the renal artery does not demonstrate stenosis of the main trunks, but stenosis of an atherosclerotic branch. We present a case of multiple atherosclerotic peripheral renal arteries, which might have caused ischemic nephropathy in an elderly hypertensive patient with advanced atherosclerosis. [source] Diagnosis and Management of Renovascular Disease and Renovascular HypertensionJOURNAL OF CLINICAL HYPERTENSION, Issue 5 2007Michael J. Bloch MD Renovascular disease is a common but complex disorder, the most common causes of which are fibromuscular dysplasia and atherosclerosis. Clinically, it can present as asymptomatic renal artery stenosis, renovascular hypertension, or ischemic nephropathy. Assessing the clinical index of suspicion remains essential in determining an appropriate diagnostic strategy. For diagnosis in patients with suspected fibromuscular disease, it may be reasonable to proceed directly to renal angiography; however, for most patients with suspected atherosclerotic disease, there are a number of noninvasive tests available that can aid in decision making. The choice of the most appropriate initial test should be based on patient characteristics, clinical presentation, and local expertise. Treatment options include medical, surgical, or percutaneous approaches. Generally, in patients with fibromuscular disease, percutaneous intervention provides durable improvement or cure of hypertension. In patients with atherosclerotic disease, the data are less consistent, and there does appear to be a group of patients who will respond well to medical management alone. As technology advances, the diagnostic and treatment paradigms will continue to evolve. [source] Reliability of intrarenal Doppler sonographic parameters of renal artery stenosisJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2003Gülgün Demirpolat MD Abstract Purpose The goal of this study was to retrospectively evaluate false-negative results of Doppler sonography in the diagnosis of renal artery stenosis (RAS) using intrarenal criteria. Methods We reviewed the clinical data and Doppler sonographic data for all patients in whom a diagnosis of RAS had been confirmed angiographically between November 1992 and January 2001. Mean intrarenal acceleration and acceleration time values,data obtained directly from color Doppler sonography,and findings of angiographic examination of the kidneys and stenotic renal arteries were evaluated. Results During the study period, 55 cases of RAS had been angiographically confirmed in 46 patients (25 male and 21 female; mean age, 50 ± 19 years [± standard deviation]). Intrarenal arterial acceleration, acceleration time values, or both were abnormal in 42 kidneys (76%) (group A) and normal in 13 kidneys (24%) (group B). The mean age ± standard deviation was significantly higher for patients in group B (60 ± 12 years) than for those in group A (47 ± 20 years) (p > 0.05). In group B, most of the stenotic lesions were atherosclerotic, and in all kidneys but 1, the lesions were located at the renal ostium or the proximal half of the artery. Conclusions Isolated use of intrarenal Doppler sonographic criteria for RAS may lead to an unacceptably high incidence of false-negative results in the diagnosis of this condition, especially in elderly patients. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:346,351, 2003 [source] Duplex Doppler sonography of transplant renal artery stenosisJOURNAL OF CLINICAL ULTRASOUND, Issue 3 2003Ruth Helena de Morais MD Abstract Purpose The aim of this study was to evaluate the accuracy of duplex Doppler sonography in diagnosing transplant renal artery stenosis (TRAS) and to determine which parameter is the most reliable for making that diagnosis. Methods Over a 3-year period, we sonographically evaluated patients who were referred for investigation of possible TRAS. We investigated the following parameters: peak systolic velocity (PSV) in the external iliac and renal arteries, acceleration time and acceleration in the intrarenal arteries, acceleration time in the renal artery, resistance index, and the ratio of the PSVs in the renal and external iliac arteries. We also used MR angiography and digital subtraction arteriography to verify the degree of stenosis. After the evaluations, the patients were classified into 2 groups, 1 with and the other without significant stenosis (> 50% narrowing of the lumen) on digital subtraction arteriography. We also included a control group of patients who had undergone renal transplantation at least 6 months before, had had a good course after transplantation, had a diastolic blood pressure of 90 mm Hg or less, and were taking a maximum of 1 antihypertensive drug. Results Our study population consisted of 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 control patients. We found statistically significant differences between the mean values of these 3 groups except for the PSV in the iliac artery and the resistance index in the intrarenal arteries. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of greater than 200 cm/second in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of greater than 1.8. Conclusions Duplex Doppler sonography is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:135,141, 2003 [source] Prevalence of vascular risk factors and vascular disease in predialysis chronic renal failureNEPHROLOGY, Issue 6 2003Johanna KOHLHAGEN SUMMARY: Patients with end-stage renal disease have a high mortality, with the majority of deaths due to vascular disease. The prevalence of vascular risk factors and vascular disease in predialysis chronic renal failure (CRF) is poorly characterized. The aim of the present study was to determine the prevalence of vascular risk factors and clinically overt vascular disease in an Australian cohort of patients with predialysis CRF. We performed a retrospective chart review of outpatients with CRF and noted demographic data, the cause of renal failure, the presence or otherwise of vascular risk factors and vascular disease and calculated glomerular filtration rate. The prevalence of overt vascular disease and modifiable vascular risk factors was calculated. One hundred and eighty patients completed the study. Eighty-nine per cent of patients had hypertension, 68% had dyslipidaemia, 32% were diabetic and 38% were previous smokers. The subgroup with diabetic nephropathy had significantly more risk factors (P < 0.001) than other groups. Twenty-seven per cent of the group had cardiovascular disease, 22% had cerebrovascular disease, 23% had peripheral vascular disease and 9% had renal artery stenosis. Patients with ischaemic nephropathy had significantly more vascular disease than other groups (P < 0.001). Patients with overt vascular disease were older, had a higher number of risk factors and a higher calcium phosphate product than those without vascular disease. In conclusion, the present study suggests a high prevalence of vascular risk factors and vascular disease in predialysis CRF. Early detection provides an opportunity for early intervention and may help reduce the development of vascular disease, and the associated mortality, once these patients progress to dialysis. [source] Does peak systolic velocity correlate with renal artery stenosis in a pediatric renal transplant population?PEDIATRIC TRANSPLANTATION, Issue 5 2006Anthony Cook Abstract:, PSV of renal transplant vessels, calculated during allograft ultrasonography, has previously been shown to correlate with TRAS. Controversy exists regarding the threshold PSV value (adult range: 1.5,3.0 ms), which should prompt further, more invasive investigations to confirm the diagnosis of TRAS. Furthermore, there is a paucity of literature regarding PSV values in the pediatric renal transplant population. In a group of pediatric renal transplant patients, we correlated post-operative renal transplant PSV values with BP, renal function (serum creatinine) and TRAS. All patients who underwent cadaveric or living-related renal transplantation at the HSC between 2001 and 2004 with at least 6 months of follow-up were reviewed through the HSC multi-organ transplant database. Post-operative allograft Doppler ultrasonography was performed during routine follow-up. PSV values obtained were correlated with BP and serum creatinine performed concomitantly. Finally, we correlated PSV in those patients who underwent more intensive investigations, including magnetic resonance and conventional angiography. Fifty-three patients underwent transplantation during the study period. Complete data available for 50/53 demonstrated a mean PSV of 2.13 m/s (range: 0.9,6.1 m/s) for all patients. Of six patients who underwent MRA for suspicion of TRAS, two (with mean PSV values of 1.93 m/s) were found to have clinically significant stenoses. Four of six without angiographic evidence of TRAS had mean PSV values of 2.22 m/s. Patients suspected of having TRAS demonstrated elevated median serum creatinine values compared with those without clinical suspicion of TRAS. However, both mean PSV and BP were not found to be statistically different in both patient subgroups. Furthermore, there was no correlation identified between PSV and serum creatinine and BP in these patient populations. Despite the utility of PSV for monitoring adult renal transplant patients, we did not find that PSV correlated with BP, nadir creatinine or identify those patients who, through subsequent investigations, were found to have TRAS in this pediatric population. Maintaining cognizance in conjunction with close clinical follow-up may identify patients at risk for this rare but potentially morbid complication of transplantation. [source] Risk Factors and Long-Term Outcome of Transplant Renal Artery Stenosis in Adult Recipients After Treatment by Percutaneous Transluminal AngioplastyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2006V. Audard Transplant renal artery stenosis (TRAS) is a common complication of kidney transplantation but attempts to identify predisposing risk factors for TRAS have yielded conflicting results. In order to determine the predisposing factors for transplant (TRAS), we retrospectively reviewed the records of 29 renal allograft recipients with TRAS treated with percutaneous transluminal angioplasty (PTA). The TRAS group was compared with a case-control group of 58 patients. Predisposing factors for TRAS included CMV infection (41.4% vs. 12.1% p = 0.0018) and initial delayed graft function (DGF) (48.3% vs. 15.5% p = 0.0018), respectively in the TRAS and the control group. Acute rejection occurred more frequently in patients from the TRAS group (48.3%) compared with the control group (27.6%), although the difference was not significant (p = 0.06). In a multivariate analysis, only CMV infection (p = 0.005) and DGF (p = 0.009) appear to be significantly and independently associated with TRAS. The long-term graft survival was significantly higher in the control group, compared with the TRAS group (p = 0.03). Our study suggests that CMV infection and DGF are two reliable risk factors for TRAS. Despite treatment by PTA with primary successful results, TRAS significantly affects long-term graft outcome. [source] Critical review of indications for renal artery stenting: Do randomized trials give the answer?,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 2 2009Uwe Schwarzwälder MD Abstract Significant renal artery stenosis (RAS) is a well accepted cause of deterioration of arterial hypertension and of renal insufficiency. Just recently, more interest has been focused on the impact of RAS on structural heart disease and patient survival. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy during the past 2 decades. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. However, none of the so far published or presented randomized controlled trials (RCT) could prove a beneficial outcome of RAS revascularization compared with medical management. As a result of these negative trials including the recently presented ASTRAL trial, referrals to endovascular renal artery revascularization went down and moreover, reimbursement of these procedures became a matter of debate. This article summarizes the background and the limitations of the so far published and still ongoing controlled trials. Moreover, we discuss why well-designed registries might give important insight on the impact of endovascular revascularization of hemodynamically relevant atherosclerotic RAS. © 2009 Wiley-Liss, Inc. [source] Treatment of instent restenosis following stent-supported renal artery angioplastyCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 3 2007Thomas Zeller MD Abstract Objectives: We prospectively studied the long-term outcome of endovascular treatment of instent renal artery stenosis (IRAS). Background: Restenosis is a considerable drawback of stent-supported angioplasty of renal artery stenosis especially in small vessel diameters. The appropriate treatment strategy is not yet defined. Patients and Methods: During a 10-year period 56 consecutive patients (65 lesions) with their first IRAS were included in a prospective follow-up program (mean follow-up 53 ± 25 months, range 6,102). Primary endpoint of the study was the reoccurrence of IRAS (, 70%) after primarily successful treatment of the first IRAS determined by duplex ultrasound. Results: Primary success rate was 100%, no major complication occurred. Nineteen lesions were treated with plain balloon angioplasty (group 1, 30%), 42 lesions with stent-in-stent placement (group 2, 65%) using various bare metal balloon expandable stents, and 4 lesions with drug-eluting stent angioplasty (group 3, 6%). During follow-up, overall 21 lesions (32%) developed reoccurrence of IRAS: n = 7/19 in group 1 (37%), n = 14/42 in group 2 (33%), and n = 0/4 in group 3 (0%; P = 0.573). Reoccurrence of IRAS was more likely to occur in smaller vessel diameters than in larger ones [3,4mm: 4/7 (57%); 5 mm: 11/26 (42%); 6 mm: 5/25 (20%); 7 mm: 1/7 (14%), P = 0.088]. Multivariable analysis found bilateral IRAS and IRAS of both renal arteries of the same side in case of multiple ipsilateral renal arteries as independent predictors for reoccurrence of IRAS. Conclusion: Treatment of IRAS is feasible and safe. The data demonstrate a nonsignificant trend towards lower restenosis with restenting of IRAS versus balloon angioplasty of IRAS. Individual factors influence the likelihood of reoccurrence of IRAS. © 2007 Wiley-Liss, Inc. [source] Gold coating and restenosis after primary stenting of ostial renal artery stenosisCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2003Thomas Zeller MD Abstract Predictors of restenosis after stent angioplasty of ostial renal artery stenosis (RAS) and long-term technical success, particularly the influence of gold coating, are unknown. During a 4-year period (1996,2000), we treated 156 consecutive patients with 219 ostial RAS of , 70% diameter stenosis. Gold-coated stents were used in 29% of RAS (n = 64); the vessel diameter ranged from 3 to 9 mm. The restenosis rate was 11.4% at 12 months, 12.2% for gold-coated stents and 11.1% for noncoated stents. Restenosis rates were 16% for , 4 mm, 17% for 5 mm, 10% for 6 mm, and 0% for , 7 mm (P , 0.05). In a backward stepwise logistic regression analysis including gold coating, vessel diameter, gender, diabetes, smoking status, as well as lesion diameter stenosis before and after stenting, vessel diameter was found the only independent predictor of restenosis (odds ratio = 0.57; 95% CI = 0.35,0.93; P = 0.02, for an increase in vessel diameter of 1 mm). Gold coating was not a significant predictor (odds ratio = 1.09; 95% CI = 0.39,3.03; P = 0.87). Seven major (4.5%) complications occurred. There were no procedural fatalities. The restenosis rate after stent angioplasty of ostial RAS is influenced by the vessel diameter but not by gold coating. Catheter Cardiovasc Interv 2003;60:1,6. © 2003 Wiley,Liss, Inc. [source] Three-dimensional visualization of renal artery stenosis by 64-channel multiple detector-row computed tomographical angiography: review of two paediatric casesACTA PAEDIATRICA, Issue 3 2010N Ueda Abstract Three-dimensional visualization of renal arteries has recently been established by helical contrast-enhanced multiple detector-row computed tomographical angiography (MDCTA) in adults. So far, no information is available on its use in children. We reported two children with renal artery stenosis detected by 64-channel MDCTA. The first patient probably had fibromuscular dysplasia and the other neurofibromatosis type1. The technique showed a left renal artery stenosis with a small left kidney in the first patient and a right renal artery stenosis in the second. Conclusion:, MDCTA is an accurate and noninvasive imaging technique, easily performed in children, and can be used as an alternative diagnostic modality in children with suspected renovascular hypertension. [source] Primary endoluminal stenting of transplant renal artery stenosis from cadaver and non-heart-beating donor kidneysCLINICAL TRANSPLANTATION, Issue 3 2006D. Ridgway Abstract:, This study evaluated the efficacy of primary endovascular stenting in cases of transplant renal artery stenosis (TRAS) from cadaver and non-heart-beating donor kidneys. Patients with TRAS (n = 13) from a single-centre transplant population (n = 476) were treated by primary percutaneous angioplasty and endovascular stenting. The short-term efficacy of this intervention is demonstrated in terms of serum creatinine, glomerular filtration rate (GFR) biochemical, anti-hypertensive medications and mean arterial blood pressure control. Stenting for TRAS was performed in male (n = 10) and female (n = 3) recipients. The median age at transplantation was 55 yr (range 10,67 yr). Stenting occurred at a median duration of 410 d post-transplantation (range 84,5799 d). Mean serum creatinine (pre, 247 ,mol/L; post, 214 ,mol/L; p = 0.002), GFR (pre, 82.6 mL/min; post, 100.9 mL/min; p<0.001), arterial blood pressure (pre, 104 mmHg; post, 97 mmHg; p = 0.036) and the number of anti-hypertensive medications required (pre, 3.4; post, 3.0; p = 0.002) showed significant improvement after post-endovascular therapy. There were no serious complications encountered. Primary endovascular stenting of TRAS produces a significant improvement in biochemical parameters of renal graft function and in blood pressure stability, with the benefit of low patient morbidity and single arterial puncture. Primary endoluminal stenting of TRAS is a safe and effective procedure for the treatment of TRAS. [source] | |||||||||||||||||||||||||