Use of Doppler Ultrasonography to Predict the Outcome of Therapy for Renal-Artery Stenosis
Jorg Radermacher, M.D., Ajay Chavan, M.D., Jorg Bleck, M.D., Annabel Vitzthum, Birte Stoess, Michael Jan Gebel, M.D., Michael Galanski, M.D., Karl Martin Koch, M.D., and Hermann Haller, M.D.
Background Prospectively identifying patients whose renal functionor blood pressure will improve after the correction of renal-arterystenosis has not been possible. We evaluated whether a highlevel of resistance to flow in the segmental arteries of bothkidneys (indicated by resistance-index values of at least 80)can be used prospectively to select appropriate patients fortreatment.
Methods We evaluated 5950 patients with hypertension for renal-arterystenosis using color Doppler ultrasonography, and we measuredthe resistance index as follows: [1 – (end-diastolic velocity÷ maximal systolic velocity)] x 100. Among 138 patientswho had unilateral or bilateral renal-artery stenosis of morethan 50 percent of the luminal diameter and who underwent renalangioplasty or surgery, the procedure was technically successfulin 131 (95 percent). Creatinine clearance and 24-hour ambulatoryblood pressure were measured before renal-artery stenosis wascorrected; 3, 6, and 12 months after the procedure; and yearlythereafter. The mean (±SD) duration of follow-up was32±21 months.
Results Among the 35 patients (27 percent) who had resistance-indexvalues of at least 80 before revascularization, the mean arterialpressure did not decrease by 10 mm Hg or more after revascularizationin 34 (97 percent). Renal function declined (defined by a decreasein the creatinine clearance of at least 10 percent) in 28 (80percent); 16 (46 percent) became dependent on dialysis; and10 (29 percent) died during follow-up. Among the 96 patients(73 percent) with a resistance-index value of less than 80,the mean arterial pressure decreased by at least 10 percentin all but 6 patients (6 percent) after revascularization; renalfunction worsened in only 3 (3 percent), all of whom becamedependent on dialysis; and 3 (3 percent) died (P<0.001 forthe comparison with patients with a resistance-index value ofat least 80).
Conclusions A renal resistance-index value of at least 80 reliablyidentifies patients with renal-artery stenosis in whom angioplastyor surgery will not improve renal function, blood pressure,or kidney survival.
The use of Doppler ultrasonography in patients with hypertensionhas led to an increase in the diagnosis of renal-artery stenosis.Patients with stenosis of more than 50 percent of the luminaldiameter of a renal artery are usually treated with angioplasty(with or without stenting) or surgery to lower blood pressureor preserve renal function. However, in 20 to 40 percent ofpatients, treatment does not improve blood pressure or renalfunction. There is no reliable way to identify these patientsprospectively.1,2,3,4,5 In addition, both angioplasty and surgeryare associated with complications, including cholesterol embolism,permanent renal failure, and death.
One possible reason for a poor response to treatment may bestructural alterations in smaller renal arteries or arteriolesdistal to the renal-artery stenosis induced by long-standinghypertension. Such hypertension may cause nephrosclerosis6,7,8,9or glomerulosclerosis,10 reducing the intrarenal vascular surfacearea and increasing vascular resistance in both the affectedand the unaffected kidney.11 Increased vascular resistance maytherefore be considered the functional equivalent of structurallyaltered vasculature.
In a previous study of patients with more than 50 percent stenosisof a renal artery, we found that neither renal function norblood pressure improved after correction of the stenosis inpatients with a resistance-index value of at least 80 in thesegmental arteries of both kidneys, as measured by Doppler ultrasonography.12The resistance index is calculated with use of the followingequation: [1 – (end-diastolic velocity ÷ maximalsystolic velocity)] x 100. These preliminary retrospective findingsprompted us to conduct a prospective study to evaluate whetherthe resistance index can be used to predict the outcome in patientswith renal-artery stenosis that is treated with angioplastyor surgery.
Methods
Identification of Renal-Artery Stenosis
Between June 1994 and November 1999, we performed color Dopplerultrasonography in 5950 patients who had hypertension and clinicalfeatures suggestive of renal-artery stenosis. All the patientshad at least one of the following: high blood pressure despitetreatment with three or more antihypertensive drugs; a diastolicblood pressure of more than 110 mm Hg; systolic and diastolicmurmurs or an isolated systolic abdominal murmur; known coronary,peripheral vascular, or cerebrovascular disease; hypokalemia;retinal hemorrhages, exudates, or papilledema; or unexplainedazotemia or a history of azotemia in association with treatmentwith an angiotensin-converting–enzyme inhibitor. The protocolwas approved by the ethics committee of Hannover Medical School,and all patients provided written informed consent.
Our technique for color Doppler ultrasonography to evaluaterenal-artery stenosis enables us to identify a reduction inthe diameter of renal arteries of at least 50 percent (i.e.,a reduction in area of at least 75 percent) with a sensitivityof 97 percent and a specificity of 98 percent.13 This methodalso provides an estimation of the severity of the stenosisthat is reproducible (coefficient of variation, 4 percent) andprecise. The results are closely correlated with those of intravascularultrasonography (correlation coefficient, 0.99) (unpublisheddata).
Treatment of Renal-Artery Stenosis
Among the 5950 patients who underwent color Doppler ultrasonography,138 patients had stenosis of at least 50 percent of one renalartery (in the case of 91 patients) or both renal arteries (inthe case of 47 patients), and these 138 patients subsequentlyunderwent angiography, angioplasty with or without stent placement,or surgery to correct these stenoses. Angiography, angioplasty,and stent placement were performed as described previously.14The operative techniques usually consisted of the placementof an aortorenal-vein or synthetic graft or thromboendarterectomy.The 138 patients were classified into two groups according totheir segmental-artery resistance-index values: those with valuesof 80 or more and those with values of less than 80.12 In afurther 16 patients who met the criteria for renal-artery stenosis,angioplasty was not performed but an angiotensin-converting–enzymeinhibitor was given because of occlusion of the renal artery(10 patients), stenosis of intrarenal vessels (3 patients),stenosis in a kidney scheduled to be removed because of a tumor(1 patient), or refusal to undergo angioplasty (2 patients,both of whom had resistance-index values of more than 80).
Base-Line Studies
Before renal-artery stenosis was corrected, blood pressure wasmeasured with a 24-hour ambulatory blood-pressure monitor (model90217, Spacelab, Redmond, Wash.), creatinine clearance (expressedin milliliters per minute per 1.73 m2, or milliliters per minute)was determined, and 24-hour urinary protein excretion, serumcholesterol concentration, and serum uric acid concentrationwere determined by standard laboratory methods. Plasma reninactivity was measured with the use of a radioimmunoassay forangiotensin I in which the temperature was 37°C and thepH was 7.4.15
Follow-up Studies
After renal-artery stenosis was corrected, the measurementsof blood pressure and creatinine clearance and the ultrasonographicprocedure were repeated at 3, 6, and 12 months and yearly thereafter.The end points of the study were the blood pressure and renalfunction at the time of the last follow-up evaluation, renalstatus, and vital status. An improvement in blood pressure wasdefined as a decrease in the mean arterial pressure of at least10 mm Hg with no change or a decrease in the number of antihypertensivedrugs. We defined diuretics and nitrates as antihypertensivedrugs, even though they may have been given for other reasons.An improvement in renal function was defined as an increasein creatinine clearance of at least 10 percent, and worseningwas defined as a decrease of at least 10 percent. The need fordialysis and vital status were ascertained by contact with thepatients or their relatives. The mean (±SD) durationof follow-up was 32±21 months.
Renal Ultrasonography
The 5950 patients were scanned in the supine position with anultrasound machine (Ultramark 9 HDI, Advanced Technology Laboratories,Bothell, Wash.) with the use of either a multifrequency curved-arraytransducer (2 to 4 MHz) or a multifrequency sector transducer(2 to 3 MHz) with a 2.5-MHz pulsed Doppler frequency and a focalzone at the depth of the renal arteries. Intrarenal Dopplersignals were obtained from segmental arteries because a clearsignal can always be obtained from these arteries.16 A clearsignal is needed for the measurement of the resistance indexto be reliable. We determined the peak systolic velocity (Vmax,in centimeters per second) and the end-diastolic velocity (Vmin,in centimeters per second) in order to calculate the dimensionlessresistance-index values: resistance index = [1 – (Vmin÷ Vmax) ] x 100. The resistance-index values were theaverage of two to three measurements in segmental arteries fromthe upper, middle, and lower third of each kidney. The courseof the main renal artery was determined with color flow imaging.The intraobserver and interobserver coefficients of variationfor the measurements of the resistance index were 2.0 percentfor the evaluation of 14 patients and 3.2 percent for the evaluationof 420 patients, respectively; the coefficient of variationwas 2.8 percent for the evaluation of 264 patients by the sameobserver on consecutive days.
Statistical Analysis
Statistical software programs (SPSS, version 10.0.5, SPSS, Chicago,and SAS, version 8.0, SAS Institute, Cary, N.C.) were used forall statistical analyses. Unpaired t-tests with Bonferroni'sadjustment for multiple tests at different time points or chi-squareanalysis was used, as appropriate, to assess differences betweengroups. Odds ratios for the worsening of renal function in associationwith various risk factors were calculated from two-by-two contingencytables with use of Fisher's exact test. For multivariate analysis,the effects of the resistance index; the degree of renal-arterystenosis; mean ambulatory 24-hour systolic and diastolic bloodpressures; pulse pressure; the presence or absence of a nocturnaldecrease in blood pressure (a decrease in blood pressure ofmore than 10 percent as compared with the daytime value); creatinineclearance; age; sex; the size of the kidney with stenosis; peripheralvenous renin activity; the presence or absence of atherosclerosisin the heart, legs, or central nervous system; the presenceor absence of diabetes mellitus; smoking status; serum uricacid concentrations; the blood-pressure response to treatmentwith angiotensin-converting–enzyme inhibitors; the numberof years since the onset of hypertension; and urinary proteinexcretion were analyzed in all 131 patients in whom revascularizationwas successful. In the stepwise forward logistic-regressionanalysis, variables with a P value of 0.1 or more were removedfrom the analysis and variables with a P value of 0.05 or lesswere retained. Unless stated otherwise, all data are expressedas means ±SD.
Results
Among the 138 patients with renal-artery stenosis, the stenosiswas corrected in 131. The stenosis was corrected with angioplastyalone in 81 patients, with angioplasty and stent placement in42 patients, and with surgery in 8 patients (placement of anaortorenal-vein graft in 6, placement of a synthetic graft in1, and thromboendarterectomy in 1). The changes in 24-hour bloodpressure and renal function after technically successful correctionwere therefore determined in these 131 patients (Table 1). Inseven patients angioplasty was unsuccessful; these patientswere considered poor candidates for surgery and were thereforeexcluded from the analysis.
Table 1. Base-Line Characteristics of 131 Patients in Whom Renal-Artery Stenosis Was Subsequently Corrected, According to the Resistance-Index Value.
After correction of renal-artery stenosis, the 35 patients withresistance-index values of at least 80 before revascularizationhad decreases in renal function (Figure 1) and little improvementin blood pressure despite increased numbers of antihypertensivedrugs (Figure 2), whereas both outcomes improved in the 96 patientswith resistance-index values of less than 80. In the lattergroup, the resistance index had a high sensitivity (96 percent)but a low specificity (53 percent) for predicting an improvementin renal function (Table 2). When the 78 patients who had impairedrenal function before revascularization (defined as a creatinineclearance that was less than 75 percent of the age-adjustednormal value17) or the 45 patients with a creatinine clearanceof less than 40 ml per minute at base line were considered,the overall accuracy of the resistance index was improved. Inthe patients with resistance-index values of less than 80 beforerevascularization there was no significant difference in thedegree of improvement in blood pressure or renal function amongthe methods used to correct the renal-artery stenosis, whereasin patients with resistance-index values of at least 80, renalfunction deteriorated less after stent placement than afterangioplasty alone (data not shown). The rate of restenosis orspontaneous stenosis was similar among patients who receiveda stent and those treated by angioplasty alone; this rate averagedabout 10 percent per year.
Figure 1. Mean (±SE) Changes in Creatinine Clearance after the Correction of Renal-Artery Stenosis, According to the Resistance-Index Value before Revascularization.
Asterisks indicate a significant difference (P<0.05) between the two groups with use of an unpaired t-test with Bonferroni's adjustment.
Figure 2. Mean (±SE) Change in Mean Arterial Pressure and the Number of Antihypertensive Drugs Taken after the Correction of Renal-Artery Stenosis, According to the Resistance-Index Values before Revascularization.
In the group of patients with a resistance index of less than 80 before revascularization, mean (±SD) blood pressure was 150±22/89±12 mm Hg initially and 135±14/80±10 mm Hg at the last follow-up visit (P<0.001); the respective values in the group of patients with a resistance index of at least 80 before revascularization were 164±21/83±16 mm Hg and 163±19/86±10 mm Hg (P=0.73). The antihypertensive drugs included angiotensin-converting–enzyme inhibitors, angiotensin II–receptor blockers, beta-blockers, calcium antagonists, alpha-blockers, direct vasodilators, diuretics, and nitrates. Asterisks indicate a significant difference (P<0.05) between the two groups with use of an unpaired t-test with Bonferroni's adjustment.
Table 2. Sensitivity, Specificity, and Positive and Negative Predictive Value of the Renal Resistance Index as a Means of Identifying the Response of Renal Function and Blood Pressure to Successful Revascularization.
On univariate analysis a number of factors present before revascularizationwere associated with an increased likelihood of a decline inrenal function (Figure 3 and Table 3). However, a resistance-indexvalue of at least 80 had the strongest association. On multivariateanalysis (Table 3), only a resistance-index value of at least80 (P<0.001), not smoking (P=0.01), a creatinine clearanceof less than 40 ml per minute (P=0.01), and male sex (P=0.05)remained independently associated with a higher risk of a declinein renal function after revascularization. Resistance-indexvalues of less than 80 (P<0.001) and smoking (P=0.02) wereassociated with the likelihood of an improvement in renal function.Similar findings were obtained in the univariate analysis withrespect to the prediction of an improvement in blood pressure:other than a resistance-index value of less than 80, the bestpredictor was a urinary protein excretion of less than 1 g perday (odds ratio, 4.5; 95 percent confidence interval, 1.7 to12). On multivariate analysis, only a resistance-index valueof less than 80 was significantly associated with the likelihoodof an improvement in blood pressure.
Figure 3. Univariate Odds Ratios for a Worsening of Renal Function after Correction of Renal-Artery Stenosis, with 95 Percent Confidence Intervals, Associated with Various Factors before Revascularization.
The absence of a nocturnal fall in blood pressure was determined from measurements of 24-hour ambulatory blood pressure. The odds ratio for captopril scintigraphy was calculated from published data.4,18 A "sudden increase in blood pressure" refers to recent worsening of hypertension or recent onset of hypertension. To convert the value for serum uric acid to micromoles per liter, multiply by 59.5. CAD denotes coronary artery disease, AOD arterial occlusive disease of the legs, CVD cerebrovascular disease, and ACE angiotensin-converting enzyme.
Table 3. Factors Associated with an Increased Risk of Worsening Renal Function or an Increased Likelihood of an Improvement in Renal Function or Blood Pressure after the Correction of Renal-Artery Stenosis in 131 Patients.
Of the 96 patients with a resistance-index value of less than80 before revascularization who underwent correction of renal-arterystenosis, 3 (3 percent) died during follow-up and 3 (3 percent)required dialysis (all 3 of whom had an initial creatinine clearanceof less than 15 ml per minute). In contrast, among the 35 patientswho had a resistance-index value of at least 80 before revascularization,10 (29 percent) died during follow-up and 16 (46 percent) becamedependent on dialysis (P<0.001 for the comparison with thepatients with a resistance-index value of less than 80). Ina multivariate analysis, an initial resistance-index value ofat least 80 (risk ratio, 19; 95 percent confidence interval,6 to 58) and a creatinine clearance of less than 40 ml per minute(risk ratio, 8; 95 percent confidence interval, 3 to 21) wereindependent predictors of the risk of renal failure or death.The mean rate of renal failure at two years among patients witha resistance-index value of at least 80 before revascularizationwas 50 percent, as compared with a rate of 5 percent among patientswith a resistance-index value of less than 80. The rate of restenosisor spontaneous stenosis was similar in the two resistance-indexgroups and averaged about 10 percent per year (data not shown).
After the correction of renal-artery stenosis, major complicationsoccurred in 8 patients (6 percent) and minor complications in10 patients (8 percent). The major complications consisted ofaortic dissection after angioplasty (one patient; resistance-indexvalue, 75), myocardial infarction during angioplasty with subsequentdeath (one patient; resistance-index value, 81), renal-arteryor intrarenal-vessel occlusion (three patients; resistance-indexvalues, 75, 80, and 80), false aneurysm requiring operativerepair (one patient; resistance-index value, 89), and dislocationof the stent into or beyond the aorta (two patients; resistance-indexvalues, 75 and 80). Minor complications consisted of intimaldissections that were corrected with stent placement (nine patients)and a false aneurysm that resolved (one patient).
Discussion
We found that a renal resistance-index value of at least 80before revascularization was a strong predictor of worseningrenal function and a lack of improvement in blood pressure despitethe correction of renal-artery stenosis. Conversely, lower resistance-indexvalues were associated with an improvement in both renal functionand blood pressure after the correction of renal-artery stenosis.These results contrast with those of a recent study of similarpatients, in which angioplasty was not found to be superiorto treatment with antihypertensive drugs alone in terms of reducingblood pressure or maintaining renal function.19 However, inthat study no effort was made to identify patients accordingto their likelihood of a response, blood pressure was measuredduring an office visit rather than at home over a period of24 hours, renal function was assessed by measurements of serumcreatinine rather than creatinine clearance, and the patientshad relatively normal renal function (mean serum creatinineconcentration, 1.2 mg per deciliter [106 µmol per liter])as compared with our patients (mean serum creatinine concentration,2.1 mg per deciliter [186 µmol per liter]). Finally, farfewer patients were treated by stenting (4 percent, vs. 32 percentin our study).
In patients with renal-artery stenosis who are not treated withangioplasty or surgery, normalization of blood pressure, especiallywith use of an angiotensin-converting–enzyme inhibitoror a beta-blocker, is not an invariable indicator of the preservationof renal function.20 On the other hand, angioplasty or surgeryis not without risk, as we found. Thus, the development of methodsto identify patients who will benefit from the interventionor, perhaps more important, those who would only be harmed byit, should have a high priority.
Among other noninvasive tests, captopril scintigraphy has beenreported to be of value in identifying patients in whom bloodpressure is likely to decrease after successful correction ofrenal-artery stenosis, with a sensitivity of 92 percent (range,84 to 100 percent) and a specificity of 78 percent (range, 62to 100 percent).4,5,21,22,23,24,25 However, this approach isless accurate in patients with renal impairment, patients withbilateral renal-artery stenosis, and patients with unilateralrenal-artery stenosis.4 Furthermore, the value of captoprilscintigraphy as a means of identifying patients in whom renalfunction is likely to improve after the correction of renal-arterystenosis has not been assessed prospectively. The ability toidentify such patients is particularly important, because preservationof renal function is the main rationale for performing angioplastyor corrective surgery in patients with renal-artery stenosisand reduced renal function.
The use of various risk factors has been proposed to differentiatebetween patients who are likely to benefit from the correctionof renal-artery stenosis and those unlikely to benefit. We foundthat urinary protein excretion of at least 1 g per day, hyperuricemia,creatinine clearance of less than 40 ml per minute, an age ofmore than 65 years, pulse pressure of at least 70 mm Hg, theabsence of a nocturnal fall in blood pressure, and the presenceof coronary artery disease, arterial occlusive disease of thelegs, or cerebrovascular disease were useful in identifyingpatients unlikely to benefit. However, none of these findingshad a predictive value approaching that of the renal resistanceindex in univariate or multivariate analyses. Smoking, a knownrisk factor for the development of renal-artery stenosis,26was not a predictor of worsening of renal function after treatment.We interpret the finding as suggesting that correction of renal-arterystenosis should not be denied patients merely because they smoke.
Renal-artery angioplasty is associated with major complicationsin about 10 to 15 percent of patients and a death rate of 1to 5 percent.27,28,29,30 Renal-artery surgery has complicationrates of 8 to 11 percent and a death rate of 2 to 8 percent.30,31,32Our results were within these ranges. Intervention should thereforebe reserved for patients in whom renal function is likely toimprove or at least stabilize or in whom blood pressure is likelyto decrease. We conclude that patients with renal resistance-indexvalues of at least 80 should be excluded from these interventions.
We are indebted to Dr. Friedrich C. Luft and Dr. JürgenWestermann for their help in preparing the manuscript; to Dr.Jürgen Schaeffer, Markus Hiß, and Dr. Oliver Eberhardfor their technical assistance with the investigation; and toDr. Hartmut Hecker, Dr. Birgit Wiese, and Dr. Hartmut Herrmannfor their assistance with the statistical analysis.
Source Information
From the Departments of Nephrology (J.R., A.V., B.S., K.M.K., H.H.), Radiology (A.C., M.G.), and Gastroenterology (J.B., M.J.G.), Medizinische Hochschule Hannover, Hannover, Germany.
Address reprint requests to Dr. Radermacher at the Department of Nephrology, Medizinische Hochschule Hannover, P.O. Box 61 01 80, D-30625 Hannover, Germany, or at radermacher.joerg{at}mh-hannover.de.
References
Grim CE, Luft FC, Yune HJ, Klatte EC, Weinberger MH. Percutaneous transluminal dilatation in the treatment of renal vascular hypertension. Ann Intern Med 1981;95:439-442.
Geyskes GG, Puylaert CBAJ, Oei HY, Mees EJ. Follow up study of 70 patients with renal artery stenosis treated by percutaneous transluminal dilatation. BMJ 1983;287:333-336.
Svetkey LP, Kadir S, Dunnick NR, et al. Similar prevalence of renovascular hypertension in selected blacks and whites. Hypertension 1991;17:678-683. [Free Full Text]
Fommei E, Ghione S, Hilson AJ, et al. Captopril radionuclide test in renovascular hypertension: a European multicentre study. Eur J Nucl Med 1993;20:617-623. [ISI][Medline]
Mann SJ, Pickering TG, Sos TA, et al. Captopril renography in the diagnosis of renal artery stenosis: accuracy and limitations. Am J Med 1991;90:30-40. [CrossRef][ISI][Medline]
Ubara Y, Hara S, Katori H, Yamada A, Morii H. Renovascular hypertension may cause nephrotic range proteinuria and focal glomerulosclerosis in contralateral kidney. Clin Nephrol 1997;48:220-223. [Medline]
Bergman SM, Curtis JJ. Possible mediators in hypertension: renal factors. Semin Nephrol 1996;16:134-139. [Medline]
Azar S, Johnson MA, Hertel B, Tobian L. Single-nephron pressures, flows, and resistances in hypertensive kidneys with nephrosclerosis. Kidney Int 1977;12:28-40. [ISI][Medline]
Tullis MJ, Zierler RE, Caps MT, Bergelin RO, Cantwell-Gab K, Strandness DE Jr. Clinical evidence of contralateral renal parenchymal injury in patients with unilateral atherosclerotic renal artery stenosis. Ann Vasc Surg 1998;12:122-127. [CrossRef][ISI][Medline]
Ruilope LM, Lahera V, Rodicio JL, Carlos Romero J. Are renal hemodynamics a key factor in the development and maintenance of arterial hypertension in humans? Hypertension 1994;23:3-9. [Free Full Text]
Schwartz GL, Strong CG. Renal parenchymal involvement in essential hypertension. Med Clin North Am 1987;71:843-858. [Medline]
Radermacher J, Vitzhum A, Stoess B, et al. Resistive index and improvement of renal function after correction of renal artery stenosis. J Am Soc Nephrol 1996;7:1554-1554.abstract
Radermacher J, Chavan C, Schäffer J, et al. Detection of significant renal artery stenosis with color Doppler sonography: combining extrarenal and intrarenal approaches to minimize technical failure. Clin Nephrol 2000;53:333-343. [ISI][Medline]
Chavan A, Galanski M, Jandeleit K, Prokop M, Schaefer C. The kissing balloons technique: simultaneous dilatation of stenoses of branch arteries at the bifurcation of the renal artery. Acta Radiol 1993;34:486-488. [Medline]
Workman RJ, Sussman CR, Burkitt DW, Liddle GW. Circulating levels of angiotensin I measured by radioimmunoassay in hypertensive subjects. J Lab Clin Med 1979;93:847-856. [ISI][Medline]
Eibenberger K, Schima H, Trubel W, Scherer R, Dock W, Grabenwoger F. Intrarenal Doppler ultrasonography: which vessel should be investigated? J Ultrasound Med 1995;14:451-455. [Abstract]
Keller F. Kidney function and age. Nephrol Dial Transplant 1987;2:382-382. [Free Full Text]
Fernandez P, Morel D, Jeandot R, Potaux L, Basse-Cathalinat B, Ducassou D. Value of captopril renal scintigraphy in hypertensive patients with renal failure. J Nucl Med 1999;40:412-417. [Free Full Text]
van Jaarsveld BC, Krijnen P, Pieterman H, et al. The effect of balloon angioplasty on hypertension in atherosclerotic renal-artery stenosis. N Engl J Med 2000;342:1007-1014. [Free Full Text]
Working Group on Renovascular Hypertension. Detection, evaluation, and treatment of renovascular hypertension: final report. Arch Intern Med 1987;147:820-829. [Abstract]
Setaro JF, Chen CC, Hoffer PB, Black HR. Captopril renography in the diagnosis of renal artery stenosis and the prediction of improvement with revascularization: the Yale Vascular Center experience. Am J Hypertens 1991;4:698S-705S-698S-705S. [Medline]
Geyskes GG, de Bruyn AJ. Captopril renography and the effect of percutaneous transluminal angioplasty on blood pressure in 94 patients with renal artery stenosis. Am J Hypertens 1991;4:685S-689S-685S-689S. [Medline]
Harward TR, Poindexter B, Huber TS, Carlton LM, Flynn TC, Seeger JM. Selection of patients for renal artery repair using captopril testing. Am J Surg 1995;170:183-187. [Medline]
Prigent A. The diagnosis of renovascular hypertension: the role of captopril renal scintigraphy and related issues. Eur J Nucl Med 1993;20:625-644. [ISI][Medline]
Mann SJ, Pickering TG. Detection of renovascular hypertension: state of the art: 1992. Ann Intern Med 1992;117:845-853.
Black HR, Cooper KA. Cigarette smoking and atherosclerotic renal artery stenosis. J Clin Hypertens 1986;2:322-330. [Medline]
Ramsay LE, Waller PC. Blood pressure response to percutaneous transluminal angioplasty for renovascular hypertension: an overview of published series. BMJ 1990;300:569-572.
Sos TA. Angioplasty for the treatment of azotemia and renovascular hypertension in atherosclerotic renal artery disease. Circulation 1991;83:Suppl I:I-162-I-166.
Pattison JM, Reidy JF, Rafferty MJ, et al. Percutaneous transluminal renal angioplasty in patients with renal failure. QJM 1992;85:883-888. [Free Full Text]
Erdoes LS, Berman SS, Hunter GC, Mills JL. Comparative analysis of percutaneous transluminal angioplasty and operation for renal revascularization. Am J Kidney Dis 1996;27:496-503. [ISI][Medline]
Libertino JA, Bosco PJ, Ying CY, et al. Renal revascularization to preserve and restore renal function. J Urol 1992;147:1485-1487. [ISI][Medline]
Van Damme H, Lombet P, Creemers E, Jeusette F, Albert A, Limet R. Surgery for occlusive renal artery disease: immediate and long-term results. Acta Chir Belg 1995;95:1-10. [Medline]
Rosenfield, K., Jaff, M. R.
(2008). An 82-Year-Old Woman With Worsening Hypertension: Review of Renal Artery Stenosis. JAMA
300: 2036-2044
[Abstract][Full Text]
Seron, D., Arns, W., Chapman, J. R.
(2008). Chronic allograft nephropathy--clinical guidance for early detection and early intervention strategies. Nephrol Dial Transplant
23: 2467-2473
[Full Text]
Mahmud, E., Smith, T. W.R., Palakodeti, V., Zaidi, O., Ang, L., Mitchell, C. R., Zafar, N., Bromberg-Marin, G., Keramati, S., Tsimikas, S.
(2008). Renal Frame Count and Renal Blush Grade: Quantitative Measures That Predict the Success of Renal Stenting in Hypertensive Patients With Renal Artery Stenosis. J Am Coll Cardiol Intv
1: 286-292
[Abstract][Full Text]
Dubel, G. J, Murphy, T. P
(2008). The role of percutaneous revascularization for renal artery stenosis. Vasc Med
13: 141-156
[Abstract]
Geddes, C C, Baxter, G M
(2008). Renal impairment. Imaging
20: 1-19
[Abstract][Full Text]
Drieghe, B., Madaric, J., Sarno, G., Manoharan, G., Bartunek, J., Heyndrickx, G. R., Pijls, N. H.J., De Bruyne, B.
(2008). Assessment of renal artery stenosis: side-by-side comparison of angiography and duplex ultrasound with pressure gradient measurements. Eur Heart J
29: 517-524
[Abstract][Full Text]
(2008). AIUM Practice Guideline for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum. J Ultrasound Med
27: 319-326
[Full Text]
De Latour, B., Delaunay, R., Rivalan, J., Heautot, J.-F., Verhoye, J.-P.
(2007). Stent-graft repair for aortic type B dissections with insidious renal malperfusion.. J. Thorac. Cardiovasc. Surg.
134: 1342-1343
[Full Text]
Mahmud, E., Cavendish, J. J., Salami, A.
(2007). Current Treatment of Peripheral Arterial Disease: Role of Percutaneous Interventional Therapies. J Am Coll Cardiol
50: 473-490
[Abstract][Full Text]
Li, J.-c., Yuan, Y., Qin, W., Wang, L., Dai, Q., Qi, Z.-h., Meng, H., Cai, S., Jiang, Y.-x.
(2007). Evaluation of the Tardus-Parvus Pattern in Patients With Atherosclerotic and Nonatherosclerotic Renal Artery Stenosis. J Ultrasound Med
26: 419-426
[Abstract][Full Text]
Krumme, B., Hollenbeck, M.
(2007). Doppler sonography in renal artery stenosis--does the Resistive Index predict the success of intervention?. Nephrol Dial Transplant
22: 692-696
[Full Text]
Cooper, C. J., Murphy, T. P.
(2007). The Case for Renal Artery Stenting for Treatment of Renal Artery Stenosis. Circulation
115: 263-270
[Full Text]
Heine, G. H., Reichart, B., Ulrich, C., Kohler, H., Girndt, M.
(2007). Do ultrasound renal resistance indices reflect systemic rather than renal vascular damage in chronic kidney disease?. Nephrol Dial Transplant
22: 163-170
[Abstract][Full Text]
Balk, E., Raman, G., Chung, M., Ip, S., Tatsioni, A., Alonso, A., Chew, P., Gilbert, S. J., Lau, J.
(2006). Effectiveness of Management Strategies for Renal Artery Stenosis: A Systematic Review. ANN INTERN MED
145: 901-912
[Abstract][Full Text]
De Bruyne, B., Manoharan, G., Pijls, N. H.J., Verhamme, K., Madaric, J., Bartunek, J., Vanderheyden, M., Heyndrickx, G. R.
(2006). Assessment of Renal Artery Stenosis Severity by Pressure Gradient Measurements. J Am Coll Cardiol
48: 1851-1855
[Abstract][Full Text]
Staub, D., Frauchiger, B.
(2006). Response to Letter by Abbas et al. Stroke
37: 1645-1645
[Full Text]
Prasad, P. V.
(2006). Functional MRI of the kidney: tools for translational studies of pathophysiology of renal disease. Am. J. Physiol. Renal Physiol.
290: F958-F974
[Abstract][Full Text]
Hirsch, A. T., Haskal, Z. J., Hertzer, N. R., Bakal, C. W., Creager, M. A., Halperin, J. L., Hiratzka, L. F., Murphy, W. R.C., Olin, J. W., Puschett, J. B., Rosenfield, K. A., Sacks, D., Stanley, J. C., Taylor, L. M. Jr, White, C. J., White, J., White, R. A., Antman, E. M., Smith, S. C. Jr, Adams, C. D., Anderson, J. L., Faxon, D. P., Fuster, V., Gibbons, R. J., Halperin, J. L., Hiratzka, L. F., Hunt, S. A., Jacobs, A. K., Nishimura, R., Ornato, J. P., Page, R. L., Riegel, B.
(2006). ACC/AHA 2005 Guidelines for the Management of Patients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic): Executive Summary A Collaborative Report From the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. J Am Coll Cardiol
47: 1239-1312
[Full Text]
White, C. J.
(2006). Catheter-Based Therapy for Atherosclerotic Renal Artery Stenosis. Circulation
113: 1464-1473
[Full Text]
Chonchol, M., Linas, S.
(2006). Diagnosis and Management of Ischemic Nephropathy. CJASN
1: 172-181
[Full Text]
Staub, D., Meyerhans, A., Bundi, B., Schmid, H. P., Frauchiger, B.
(2006). Prediction of Cardiovascular Morbidity and Mortality: Comparison of the Internal Carotid Artery Resistive Index With the Common Carotid Artery Intima-Media Thickness. Stroke
37: 800-805
[Abstract][Full Text]
Nosadini, R., Velussi, M., Brocco, E., Abaterusso, C., Carraro, A., Piarulli, F., Morgia, G., Satta, A., Faedda, R., Abhyankar, A., Luthman, H., Tonolo, G.
(2006). Increased Renal Arterial Resistance Predicts the Course of Renal Function in Type 2 Diabetes With Microalbuminuria. Diabetes
55: 234-239
[Abstract][Full Text]
Garcia-Criado, A., Gilabert, R., Nicolau, C., Real, M. I., Muntana, X., Blasco, J., Ganau, S., Bru, C.
(2005). Value of Doppler Sonography for Predicting Clinical Outcome After Renal Artery Revascularization in Atherosclerotic Renal Artery Stenosis. J Ultrasound Med
24: 1641-1647
[Abstract][Full Text]
Cheung, C. M., Hegarty, J., Kalra, P. A.
(2005). Dilemmas in the management of renal artery stenosis. Br Med Bull
73-74: 35-55
[Abstract][Full Text]
Garovic, V. D., Textor, S. C.
(2005). Renovascular Hypertension and Ischemic Nephropathy. Circulation
112: 1362-1374
[Full Text]
de Silva, R., Nikitin, N. P., Bhandari, S., Nicholson, A., Clark, A. L., Cleland, J. G.F.
(2005). Atherosclerotic renovascular disease in chronic heart failure: should we intervene?. Eur Heart J
26: 1596-1605
[Abstract][Full Text]
Claus, T., Schmitt, R., Stabroth, C., Luft, F. C., Kettritz, R., Gross, C. M.
(2005). Where do we stand with renovascular hypertension?. Nephrol Dial Transplant
20: 1495-1498
[Full Text]
Verhoye, J.-P., De Latour, B., Heautot, J.-F.
(2005). Return of Renal Function after Endovascular Treatment of Aortic Dissection. NEJM
352: 1824-1825
[Full Text]
Fliser, D., Wagner, K.-K., Loos, A., Tsikas, D., Haller, H.
(2005). Chronic Angiotensin II Receptor Blockade Reduces (Intra)Renal Vascular Resistance in Patients with Type 2 Diabetes. J. Am. Soc. Nephrol.
16: 1135-1140
[Abstract][Full Text]
Bolduc, J. P., Oliva, V. L., Therasse, E., Giroux, M.-F., Bouchard, L., Perreault, P., Cliche, A., Soulez, G.
(2005). Diagnosis and Treatment of Renovascular Hypertension: A Cost-Benefit Analysis. Am. J. Roentgenol.
184: 931-937
[Abstract][Full Text]
Silva, J. A., Chan, A. W., White, C. J., Collins, T. J., Jenkins, J. S., Reilly, J. P., Ramee, S. R.
(2005). Elevated Brain Natriuretic Peptide Predicts Blood Pressure Response After Stent Revascularization in Patients With Renal Artery Stenosis. Circulation
111: 328-333
[Abstract][Full Text]
Geddes, C C, Baxter, G M
(2005). Renal impairment. Imaging
17: 1-18
[Abstract][Full Text]
Marone, L. K., Cambria, R. P.
(2004). Revascularization for Renal Function Retrieval: Which Patients Will Benefit?. PERSPECT VASC SURG ENDOVASC THER
16: 249-258
[Abstract]
Zierler, R. E.
(2004). Atherosclerotic Renovascular Disease: Natural History and Diagnosis. PERSPECT VASC SURG ENDOVASC THER
16: 299-310
[Abstract]
Textor, S. C.
(2004). Expert Commentary. PERSPECT VASC SURG ENDOVASC THER
16: 311-312
Textor, S. C.
(2004). Ischemic Nephropathy: Where Are We Now?. J. Am. Soc. Nephrol.
15: 1974-1982
[Abstract][Full Text]
Olin, J. W., Kaufman, J. A., Bluemke, D. A., Bonow, R. O., Gerhard, M. D., Jaff, M. R., Rubin, G. D., Hall, W.
(2004). Atherosclerotic Vascular Disease Conference: Writing Group IV: Imaging. Circulation
109: 2626-2633
[Full Text]
Creager, M. A., Jones, D. W., Easton, J. D., Halperin, J. L., Hirsch, A. T., Matsumoto, A. H., O'Gara, P. T., Safian, R. D., Schwartz, G. L., Spittell, J. A.
(2004). Atherosclerotic Vascular Disease Conference: Writing Group V: Medical Decision Making and Therapy. Circulation
109: 2634-2642
[Full Text]
Weinrauch, L. A., D'Elia, J. A.
(2004). Renal artery stenosis: "fortuitous diagnosis," problematic therapy. J Am Coll Cardiol
43: 1614-1616
[Full Text]
Slovut, D. P., Olin, J. W.
(2004). Fibromuscular Dysplasia. NEJM
350: 1862-1871
[Full Text]
Ayerdi, J., Hodgson, K. J.
(2004). Balloon Angioplasty and Stenting for Renovascular Occlusive Disease. PERSPECT VASC SURG ENDOVASC THER
16: 25-38
[Abstract]
Soulez, G., Therasse, E., Qanadli, S. D., Froment, D., Leveille, M., Nicolet, V., Turpin, S., Giroux, M.-F., Guertin, M. C., Oliva, V. L.
(2003). Prediction of Clinical Response After Renal Angioplasty: Respective Value of Renal Doppler Sonography and Scintigraphy. Am. J. Roentgenol.
181: 1029-1035
[Abstract][Full Text]
Radermacher, J., Mengel, M., Ellis, S., Stuht, S., Hiss, M., Schwarz, A., Eisenberger, U., Burg, M., Luft, F. C., Gwinner, W., Haller, H.
(2003). The Renal Arterial Resistance Index and Renal Allograft Survival. NEJM
349: 115-124
[Abstract][Full Text]
Marsden, P. A.
(2003). Predicting Outcomes after Renal Transplantation -- New Tools and Old Tools. NEJM
349: 182-184
[Full Text]
Schoenberg, S. O., Rieger, J., Johannson, L. O., Dietrich, O., Bock, M., Prince, M. R., Reiser, M. F.
(2003). Diagnosis of renal artery stenosis with magnetic resonance angiography: update 2003. Nephrol Dial Transplant
18: 1252-1256
[Full Text]
van Onna, M., Houben, A. J.H.M., Kroon, A. A., Wierema, T. K.A., Koster, D., van Engelshoven, J. M.A., de Leeuw, P. W.
(2003). Asymmetry of Renal Blood Flow in Patients With Moderate to Severe Hypertension. Hypertension
41: 108-113
[Abstract][Full Text]
Gray, B. H, Olin, J. W, Childs, M. B., Sullivan, T. M, Bacharach, J M.
(2002). Clinical benefit of renal artery angioplasty with stenting for the control of recurrent and refractory congestive heart failure. Vasc Med
7: 275-279
[Abstract]
Weber-Mzell, D., Kotanko, P., Schumacher, M., Klein, W., Skrabal, F.
(2002). Coronary anatomy predicts presence or absence of renal artery stenosis. A prospective study in patients undergoing cardiac catheterization for suspected coronary artery disease. Eur Heart J
23: 1684-1691
[Abstract][Full Text]
Zucchelli, P. C.
(2002). Hypertension and Atherosclerotic Renal Artery Stenosis: Diagnostic Approach. J. Am. Soc. Nephrol.
13: S184-186
[Abstract][Full Text]
Textor, S. C.
(2002). Progressive Hypertension in a Patient With "Incidental" Renal Artery Stenosis. Hypertension
40: 595-600
[Full Text]
Grant, E. G., Barr, L. L., Borgstede, J., Gooding, G. A.W., Hamper, U. M., Hertzberg, B. S., Horrow, M., Kane, R. A., Kremkau, F., Meilstrup, J. W., Needleman, L., Piccoli, C. W., Townsend, R. R., Merritt, C. R.B., Perlmutter, G. S.
(2002). AIUM Standard for the Performance of an Ultrasound Examination of the Abdomen or Retroperitoneum. J Ultrasound Med
21: 1182-1187
[Abstract][Full Text]
Rundback, J. H., Sacks, D., Kent, K. C., Cooper, C., Jones, D., Murphy, T., Rosenfield, K., White, C., Bettmann, M., Cortell, S., Puschett, J., Clair, D., Cole, P., for the AHA Councils on Cardiovascular Radiology,,
(2002). Guidelines for the Reporting of Renal Artery Revascularization in Clinical Trials. Circulation
106: 1572-1585
[Full Text]
Haller, C.
(2002). Arteriosclerotic renal artery stenosis: conservative versus interventional management. Heart
88: 193-197
[Full Text]
Lee, H.-Y., Grant, E. G.
(2002). Sonography in Renovascular Hypertension. J Ultrasound Med
21: 431-441
[Abstract][Full Text]
Weise, W. J, Jaffery, J. B
(2002). Review: CT angiography and magnetic resonance imaging are the best less invasive tests for renal artery stenosis. Evid. Based Med.
7: 58-58
[Full Text]
Radermacher, J., Ellis, S., Haller, H.
(2002). Renal Resistance Index and Progression of Renal Disease. Hypertension
39: 699-703
[Abstract][Full Text]
Krumme, B., Mann, J. F. E.
(2001). Atherosclerotic renal artery stenosis in 2001--are we less confused than before?. Nephrol Dial Transplant
16: 2124-2127
[Full Text]
Previous
