Indications for renal arteriography at the time of coronary arteriography: a science advisory from the American Heart Association Committee on Diagnostic and Interventional Cardiac Catheterization, Council on Clinical Cardiology, and the Councils on Cardiovascular Radiology and Intervention and on Kidney in Cardiovascular Disease.

Atherosclerotic renal artery stenosis is commonly present in patients with clinically manifest atherosclerosis in other vascular beds and is independently associated with increased cardiovascular morbidity and mortality. Screening tests such as renal angiography should be selectively applied to patients at high risk for renal artery stenosis who are potential candidates for revascularization. This multispecialty consensus document describes the rationale for patient selection for screening renal angiography at the time of cardiac catheterization.

Predictive factors of in-stent restenosis in renal artery stenting: a retrospective analysis.

PURPOSE: To retrospectively evaluate the role of clinical and procedural factors in predicting in-stent restenosis in patients with renovascular disease treated by renal artery stenting. METHODS: From 1995 to 2002, 147 patients underwent renal artery stenting for the treatment of significant ostial atherosclerotic stenosis. Patients underwent strict clinical and color-coded duplex ultrasound follow-up. Ninety-nine patients (111 stents), with over 6 months of continuous follow-up (mean 22+/-12 months, range 6-60 months), were selected and classified according to the presence (group A, 30 patients, 32 lesions) or absence (group B, 69 patients, 79 lesions) of significant in-stent restenosis. A statistical analysis was performed to identify possible preprocedural and procedural predictors of restenosis considering the following data: sex, age, smoking habit, diabetes mellitus, hypertension, serum creatinine, cholesterol and triglyceride levels, renal artery stenosis grade, and stent type, length and diameter. RESULTS: Comparing group A and B patients (chi(2) test), a statistically significant relation was demonstrated between stent diameter and length and restenosis: the risk of in-stent restenosis decreased when the stent was >/=6 mm in diameter and between 15 and 20 mm in length. This finding was confirmed by multiple logistic regression analysis. Stent diameter and length were proved to be significantly related to in-stent restenosis also when evaluating only patients treated by Palmaz stent (71 stents). CONCLUSION: Although it is based on a retrospective analysis, the present study confirms the importance of correct stent selection in increasing long-term patency, using stents of at least 6 mm in diameter and with a length of approximately 15-20 mm.

[Proposal of a clinical prediction score for atheromatous renal artery stenosis]. / Proposition d'un score clinique de prédiction d'une sténose rénale athéromateuse.

UNLABELLED: Renal vascular pathologies are important causes of the chronic renal failure progression. This work aims to define retrospectively a score based on simple clinical and paraclinical helping to select atheromatous renal stenosis affected patients; 67 patients more than 50 years old have been explored by arteriography because of degradation of the renal function or hypertension: 45 of them had one, or many, significant stenosis of the renal arteries. Were analyzed: clinical data: age, weight, sex, blood pressure, previous ateromatous lesions (cardiac, peripheral, aortic), smoking, associated diabetes; biological data: serum cholesterol and creatinine, creatinine variation under angiotensin-coverting enzyme inhibitor or sodium depletion, kaliemia; radiologic data: kidney size through scanning, renal arterial and aortic calcifications on abdominal plain films and profile. The group with and without stenosis differed considerably for age (68.9 vs 64 years old, p < 0.05), smoking (26.3 vs 11.5 packet-year, p < 0.001), variation of creatinine after sensibilisation (140 mumol/l vs 17 mumol/l, p < 0.001), presence of arterial calcification (p < 0.001). A score taking in to account these four criteria was established with performances in terms of specificity and sensibility amounted to 83%. CONCLUSION: The reliable aspect of this score enabling to define a group seriously risking a renal stenosis must be checked through a prospective study.

Stent placement in ostial and nonostial atherosclerotic renal arterial stenoses: a prospective follow-up study.

PURPOSE: To compare the results of balloon percutaneous transluminal renal angioplasty (PTRA) and stent placement in atherosclerotic ostial, proximal, and isolated truncal stenoses. MATERIALS AND METHODS: Between January 1994 and April 1998 the authors prospectively followed up 163 consecutive patients with 200 atherosclerotic renal arterial lesions after primary PTRA or primary stent placement. Duplex ultrasonography was performed 1 day and 3, 6, and 12 months later. RESULTS: The primary 12-month PTRA patency rates were 34% (21 of 33 atherosclerotic lesions) for ostial stenoses, 65% (20 of 60) for proximal stenoses, and 83% (five of 30) for truncal stenoses (chi(2) value, 15.63; P <.001). The corresponding stent patency rates were 80% (four of 21), 72% (nine of 34), and 66% (five of nine), respectively (chi(2) value, 4.11; not significant). Significant stent-related reduction in risk of restenosis was limited to the ostial stenoses (P =.002). CONCLUSION: Renal arterial stent placement considerably improves patency in ostial stenoses, but compared with the technically successful PTRA, it does not significantly improve primary patency in proximal and isolated truncal renal arterial stenoses.

A fuzzy classification system to predict renal artery restenosis after angioplasty.

Percutaneous transluminal angioplasty (PTRA) has emerged as a promising treatment for patients with renovascular hypertension. However, the benefit of this procedure is hampered by restenosis that frequently occurs within around 6 months after a successful angioplasty. This paper presents a fuzzy classification system based on a fuzzy pattern matching model that is being developed to evaluate the risk of short-term restenosis. First, identified classes are represented by fuzzy prototypes that take into account the imprecision of the criteria. Second, the system is applied to angiographic features of given stenoses and provides the membership degree of these stenosis to the two classes "short term restenosis" or "no restenosis". The fuzzy classifier's performances have been tested on twenty two patients who underwent balloon angioplasty in the context of a French multicenter randomized trial EMMA. With the fuzzy classifier, restenosis were predicted prospectively with 100% while its sensitivity is about 73%. The fuzzy classification system is expected to become a reliable tool to predict PTRA outcomes.

[Classification of hemodynamic changes in renal artery stenosis using cine magnetic resonance phase contrast flow measurements]. / Einstufung hämodynamischer Veränderungen bei Nierenarterienstenosen mittels MR-Cine-Phasenkontrastflussmessungen.

PURPOSE: To evaluate the use of high-temporal resolution cine MR phase-contrast flow measurements for assessment of flow dynamics in renal artery stenosis (RAS). MATERIAL AND METHODS: In a dog model, cine MR flow measurements were validated by comparing the MR flow data to an invasive transit-time ultrasound reference technique for different degrees of RAS. Cardiac-gated MR flow curves were recorded in 56 renal arteries of 28 patients with a temporal resolution of at least 32 ms. In all cases RAS was confirmed by digital subtraction angiography (DSA). Abnormalities of flow dynamics were assessed in the calculated flow curves using the MR parameters mean flow, maximum velocity, and time to systolic maximum. RESULTS: By means of the MR blood flow parameters high-grade stenoses (> 50%, n = 23) were detected with sensitivity of 100% and specificity of 94% with reference to DSA. The overall differentiation between stenoses (n = 37) and non-stenosed vessels (n = 19) revealed a sensitivity of 87% and a specificity of 100%. CONCLUSION: Analysis of cardiac-gated MR flow curves provides a non-invasive method to assess the hemodynamic significance of RAS and thus allows a functional evaluation in relation to the morphologic characteristics of the stenosis.

Fuzzy classification of renal artery lesions from angiograms in the context of angioplasty.

This paper describes a system that automatically classifies renal artery lesions from arteriograms in the context of Percutaneous Transluminal Renal Angioplasty (PTRA). PTRA outcomes have been categorized into type A (success) or type B (failure) according to morphological features. The morphological features are naturally represented by fuzzy sets. The classification process is based on a fuzzy pattern matching procedure between fuzzy prototypes of lesions in the classes A and B and fuzzy quantified assessments of lesions in angiograms. The system provides a meaningful membership degree to the class rather than an abrupt yes or no answer. The system is expected to be a good framework to study the technical results of PTRA according to the anatomy of the lesion.

[Treatment of renal artery stenosis]. / Traitement des sténoses artérielles rénales.

Management of renovascular disease can be based on surgical revascularization, medical therapy or interventional radiology. Results obtained with transluminal angioplasty, as compared to surgery, indicate that interventional radiology should be used as first treatment in patients with renovascular hypertension without renal failure. The best indications are treatments of fibrous dysplasia, and atherosclerotic stenosis complicated with pulmonary oedema. In case of restenosis, observed mainly with atherosclerotic stenosis, a second angioplasty eventually combined with stent implantation can be performed. Surgical repair is indicated when angioplasty has not been successful or when arterial lesions are too complex.

The evolution of surgery for renovascular occlusive disease.

Renal artery stenotic disease is the most common form of surgically correctable hypertension. Occlusive lesions of the renal artery are categorized as: arteriosclerotic, fibrodysplastic (intimal fibroplasia, medial fibrodysplasia, perimedial dysplasia) and developmental. The incidence of stroke, heart disease and renal failure has been reduced with contemporary drug management of hypertensive vascular disease, but similar salutary outcomes have not accompanied the medical treatment of renin-mediated renovascular hypertension. Selection of patients for operation implies documentation that a renal artery stenosis is of functional importance. Advances in the surgical management of renovascular hypertension have evolved over the past 50 years, such that carefully performed reconstructions benefit 85-95% of properly selected patients.

Natural history of atherosclerotic renal artery stenosis: a prospective study with duplex ultrasonography.

PURPOSE: Although the prevalence of renal artery stenosis in patients with peripheral arterial disease is in the range of 30% to 40%, the role of renal revascularization in patients without severe hypertension or kidney failure is controversial. Duplex scanning is a noninvasive technique that is ideally suited for screening and follow-up of renal artery disease. The purpose of this study was to document the natural history of renal artery stenosis in patients who were not candidates for immediate renal revascularization. METHODS: Eighty-four patients with at least one abnormal renal artery detected by duplex scanning were recruited from patients being screened for renal artery stenosis. Of the 168 renal artery/kidney sides, 29 were excluded (15 prior interventions, 6 nondiagnostic duplex scans, 8 presumed nonatherosclerotic lesions), leaving 80 patients with 139 sides for the follow-up protocol. Renal arteries were classified as normal, less than 60% stenosis, 60% or greater stenosis, or occluded by use of previously validated criteria. RESULTS: The study group included 36 men and 44 women with a mean age of 66 years who were monitored for a mean interval of 12.7 months. The initial status of the 139 renal arteries was normal in 36, less than 60% stenosis in 35, 60% or greater stenosis in 63, and occluded in 5. Although none of the initially normal renal arteries showed disease progression, the cumulative incidence of progression from less than 60% to 60% or greater renal artery stenosis was 23% +/- 9% at 1 year and 42% +/- 14% at 2 years. All four renal arteries that progressed to occlusion had 60% or greater stenoses at the initial visit, and for those sides with a 60% or greater stenosis, the cumulative incidence of progression to occlusion was 5% +/- 3% at 1 year and 11% +/- 6% at 2 years. The mean decrease in kidney length associated with progression of renal artery stenosis to occlusion was 1.8 cm. CONCLUSIONS: Progression of renal artery stenosis, as defined in this study, occurs at a rate of approximately 20% per year. Progression to occlusion is associated with a marked decrease in kidney length. Whether this natural history can be improved by earlier intervention for renal artery stenosis remains to be determined.

[Etiology and classification of arterial stenosis of transplanted kidney]. / Etiologiia i klassifikatsiia stenoza arterii peresazhennoi pochki.

Stenosis of the artery of a transplanted kidney, which developed in late-term periods after allogeneic kidney transplantation, was revealed in 30 patients, which accounts for 6% of the total number of patients who underwent transplantation. The authors discuss the etiology of this complication in detail and suggest their own classification.

[Renal artery pathology and its therapeutic indications in the child]. / La pathologie des artères rénales et ses indications thérapeutiques chez l'enfant.

Between September 1955 and January 1990, 94 pediatric patients were managed for renovascular hypertension caused by renal artery occlusive disease. Patients (50 boys and 44 girls) were aged 4 days to 17 years (median age: 7 years). At initial evaluation, 34 patients had symptoms of hypertensive encephalopathy or acute heart failure, 36 had moderate symptoms, and 24 were symptom-free. Sixty-five cases were classified on the basis of clinical, radiological, and histological features, as follows: neurofibromatosis (17), fibromuscular dysplasia (11), diffuse arterial calcified elastopathy (11), renal artery thrombosis (10), Williams syndrome (4), Takayashu disease (3), and miscellaneous diseases (9). In the 29 remaining patients, classification was based only on radiological features: causes included unilateral renal artery stenosis (15), bilateral renal artery stenosis with or without aortic stenosis (11), and miscellaneous disorders (3). Surgical treatment consisted in 47 renal revascularization, procedures (14 aortorenal bypasses, 8 aortorenal reimplantations, 9 anastomoses in the upper mesenteric arterial system, 7 autotransplantations, 4 resection-reanastomosis procedures, and 5 miscellaneous procedures). Renal revascularization failed in 15 cases (32%) (because of thrombosis in 14 cases and dehiscence in one). Residual or recurrent stenosis was seen in 7 arteries, whereas the anatomic result was satisfactory in 25 arteries (53%). Blood pressures returned to normal in 16 of 40 (40%) patients successfully treated by revascularization. An additional 25 patients recovered normal blood pressure values after primary nephrectomy (21), partial nephrectomy (4) or nephrectomy after failed renal revascularization.(ABSTRACT TRUNCATED AT 250 WORDS)

Juxtarenal aortic atherosclerosis. Surgical experience and functional result.

Ninety patients underwent combined aortic (90) and renal artery (138 arteries) reconstruction for severe, symptomatic aortic occlusive disease (47 patients), aortic aneurysmal disease (30 patients), and visceral atherosclerosis (13 patients). Transaortic endarterectomy was used for 67% of renal artery reconstructions and 69% of visceral arteries. Aortic reconstruction required prosthetic grafting in 74%. A standard transabdominal approach was used in 72 of 90 patients (80%), and thoraco-retroperitoneal exposure was necessary in 18 patients. Perioperative mortality was 9% (8/90) and morbidity 16% (14/90). Ninety per cent of the patients were evaluated at long-term (mean 32 months). Hypertension was cured or improved at discharge in 82% (59/72), and in 96% hypertension improvement was sustained during the follow-up interval. Renal function was improved or preserved in 93% (40/43) at discharge, and this response was sustained in 84% during the follow-up period. Late mortality (8/74, 11%) was lower than expected and is attributed to the technique of combined repair, the cure and control of hypertension, the prevention of ongoing renal ischemia, and the preservation of renal function.

Renal artery stenosis: anatomic classification for percutaneous transluminal angioplasty.

Most lesions that decrease renal blood flow originate within the renal artery; however; large, aortic, atherosclerotic plaques can overhang the renal ostium producing a functional renal artery stenosis. At the Hospital of the University of Pennsylvania, 45 consecutive percutaneous transluminal angioplasties were examined retrospectively and classified as to site of the obstructing lesions and clinical outcome. Stenoses within the renal artery responded very well to angioplasty, with 83% of patients showing either an excellent or good result. Conversely, when aortic plaques were responsible for inflow obstruction, 76% of patients responded poorly or not at all to balloon dilatation. It is proposed that this disparity of response reflects the anatomic differences in the orientation of elastic and collagen fibers of the muscularis and advential layers of the renal artery and the aorta.

Prevention of transplant renal artery stenosis.

Transplant renal artery stenosis occurred in 17 of 142 consecutive transplants (12 percent). All stenoses were in the renal artery distal to the anastomosis and two separate forms are recognized: angulation and segmental stenosis. Successful surgical correction in 12 of 17 patients relieved the hypertension and resulted in improved renal function. No patients receiving dipyridamole, a drug which inhibits platelet aggregation and intravascular fibrin deposition, developed segmental renal artery stenosis. No other factors could be identified which were important in either causing or preventing renal artery stenosis. Since intrarenal vascular changes are an integral aspect of rejection, the protection afforded by dipyridamole against segmental renal artery stenosis indicates that segmental stenosis is probably a manifestation of rejection.

[Fibrous dysplasia of renal arteries (terminology, classification, clinical aspects and diagnosis)]. / Fibroznaia displaziia pochechnykh arterii (terminologiia, klassifikatsiia, klinika i diagnostika)

The examination was conducted in 72 patients with renovascular hypertension caused by fibromuscle dysplasia of the renal arteries. According to the authors, fibromuscle dysplasia of the renal arteries stands third after atherosclerosis and non-specific aorto-arteritis. Among the preliminary diagnostic measures of importance are such as intravenous urography, isotope renography, scintigraphy, but their value is much lower than in cases of atherosclerotic stenosis or stenosis due to non-specific aorto-arteritis, which is attributed to a good collateral circulation in the kidney. The diagnosis is made on the basis of serial angiography data. Of importance is also the method of selective renal angiography with functional tests with acetylcholoine and adrenalin. To characterize the form of renal artery pathology, three types of stenosis are distinguished: monofocal, multifocal, tubular. The terminology and classification are discussed, and a new term is suggested: "fibrous dysplasia of renal arteries".