Is duplex scanning the best screening test for renal artery stenosis?

Screening for renal artery stenosis is indicated in patients with suspected renovascular hypertension or ischemic nephropathy to identify those who could benefit from renal artery interventions. The critical requirements for a clinically useful screening test include safety, low cost, and a high sensitivity or low false-negative rate. Arteriography remains the "gold standard" for the anatomic diagnosis of renal artery disease, but it is unsuitable for screening because of its high cost and invasive nature. Although renal duplex scanning technically is difficult, experienced laboratories have been able to achieve sensitivities and specificities in the range of 93% to 98% for identification of stenoses in the main renal arteries. Renal duplex scanning also provides a method for assessing the renal parenchyma and predicting the clinical outcome of renal revascularization. The principal limitation of renal duplex scanning is failure to identify accessory renal arteries. The finding of one or more widely patent main renal arteries makes ischemic nephropathy unlikely, because this condition results from "total" renal ischemia. However, renovascular hypertension can be present with normal main renal arteries when there are isolated stenoses involving accessory renal arteries, so further testing may be indicated in selected hypertensive patients with normal main renal arteries by duplex scanning. Currently, duplex scanning in a qualified vascular laboratory arguably is the best screening test for renal artery stenosis. Other methods for assessing the renal arteries, particularly spiral computed tomography and magnetic resonance angiography, are evolving rapidly and also may play a role in screening of selected patients.     

Outcomes of renal artery angioplasty and stenting using low-profile systems

OBJECTIVE: Renal artery percutaneous transluminal angioplasty (RPTA) and stenting (RAS) are accepted therapies for selected patients with renovascular hypertension and chronic renal insufficiency. We evaluated the outcomes and complications of RAS performed by vascular surgeons at our institution with modern low-profile systems. METHOD: We retrospectively analyzed all RPTA and RAS procedures attempted with the use of low-profile systems from June 2000 to September 2003. Eighty-two patients (96 arteries) with atherosclerotic renal artery stenosis were treated. Indication for treatment was hypertension in 44 (54%) and chronic renal insufficiency in 38 (46%). Technical success, complication rates, clinical success for control of hypertension or renal insufficiency, restenosis, and survival were reviewed with a mean follow-up of 1 year. RESULTS: Ninety-three arteries were treated with stents, three with RPTA only. Primary technical success was 95%, with 98% overall technical success. Major complications occurred in 6.1% and minor complications in 1.2%. Hypertension was improved in 81% at 1 year. Renal function was improved in 23%, stable in 53%, and worse in 24% at 1 year. Restenosis was seen by routine duplex surveillance in 25% at 1 year. Restenosis associated with clinical deterioration and confirmed by angiogram was seen in 10%. The overall 3-year survival was 83%. CONCLUSION: RPTA/RAS can be performed with low-profile systems with excellent technical success, low complication rates, and clinical outcomes that compare favorably with prior reports.     

Surgical treatment of renal artery dissection in 25 patients: indications and results

OBJECTIVE: Results of surgical revascularization in 25 patients with renal artery dissection (RAD) over 14 years, with mean follow-up of 55.3 months (range, 10-111 months), were analyzed. Indications for surgery were renovascular hypertension and preservation or improvement of kidney function. PATIENTS AND METHODS: Two patients (both 20 years of age) underwent emergency surgery after severe trauma; 23 patients (mean age, 41 years) underwent elective surgery in a chronic stage of disease. Preoperative, postoperative, and follow-up examinations included duplex ultrasound scanning, determination of serum creatinine and urea concentrations, and evaluation of blood pressure control. All long-term patients underwent digital subtraction angiography preoperatively and postoperatively. All histologic specimens of resected renal arteries were re-evaluated by two independent pathologists. RESULTS: Histologic re-evaluation confirmed the traumatic origin in 2 patients who underwent emergency surgery and 1 who underwent elective surgery. Renal artery dissection developed spontaneously, with no histologic signs of trauma or fibromuscular dysplasia, in 22 patients. In 17 revascularized kidneys (61%) a kidney infarction had already developed preoperatively, and the kidneys were diminished in size or function. Results of revascularization and improvement of hypertension depended on preoperative extent of renal infarction. Hypertension resolved or improved in 86% of patients without preoperative kidney damage, but in only 38% with preoperatively damaged kidneys. Kidney function was preserved in 23 of 28 revascularized kidneys (82%). During follow-up, late renal artery occlusion developed in 3 kidneys. CONCLUSIONS: Renal artery dissection can be effectively treated with surgical revascularization. Primary nephrectomy should be considered only in patients with a large ischemic kidney infarction, with significant deterioration of kidney function, to effectively cure or improve severe renovascular hypertension.     

Renal autotransplantation: current perspectives.

Autotransplantation, with or without an extracorporeal renal operation, has been done 39 times in 37 patients. Indications for the procedure included several ureteral injury in 4 patients, failed supravesical diversion in 2, renal carcinoma in a solitary kidney in 1, renovascular hypertension in 1 and donor arterial reconstruction before renal transplantation in 29. Success was obtained in all but 2 procedures, both of which involved previously operated kidneys with severe inflammation and adhesions involving the renal pelvis and pedicle. Based on our experience and a review of currently available literature we believe that renal autotransplantation and extracorporeal reconstruction can provide the best solution for patients with severe renovascular and ureteral disease not correctable by conventional operative techniques. The technique can be of particular value in removing centrally located tumors in solitary kidneys and in preparing donor kidneys with abnormal arteries for renal transplantation. The role of autotransplantation in the management of advanced renal trauma and calculus disease is less clear. A long-term comparison of patients treated by extracorporeal nephrolithotomy versus conventional lithotomy techniques will be necessary before a conclusion is reached in these disease categories.     

Captopril renography and duplex Doppler sonography in the diagnosis of renovascular hypertension

Background. The purpose of this prospective study was to determine the clinical usefulness of captopril renal scintigraphy and duplex Doppler sonography in detecting haemodynamically significant renal artery stenosis (⩾60%) and predicting cure or improvement of hypertension following revascularisation. Methods. Twenty-eight patients with moderate or high index of clinical suspicion of renovascular hypertension underwent both captopril renal scintigraphy and duplex Doppler sonography before undergoing renal angiography. Patients with angiographically proved (⩾60%) RAS were treated by percutaneous transluminal renal angioplasty unless it was contraindicated. Results. The results of captopril renal scintigraphy and duplex Doppler sonography were compared by renal angiography of 45 renal arteries in 28 patients. Eleven renal arteries were excluded from further comparison, because no accurate Doppler signal could be obtained. The sensitivity and specificity of captopril renal scintigraphy in the identification of RAS (⩾60%) was 78% and 81% respectively. The sensitivity of duplex Doppler sonography was 83% and the specificity was 81%. Positive predictive values of both tests for blood pressure cure or improvement after PTRA were 86% for CRS and 85% for DDS. Conclusions. Captopril renal scintigraphy and duplex Doppler sonography are comparable tests for detection of patients with haemodynamically significant renal artery stenosis (⩾60%). Positive predictive values of both tests for cure or improvement of hypertension after percutaneous transluminal renal angioplasty are good and comparable.     

Evaluation of duplex ultrasound and captopril renography for detection of renovascular hypertension

BACKGROUND: Renovascular hypertension is the most common form of curable secondary hypertension and, if untreated, may lead to end-stage kidney disease. Given that renal function and hypertension may improve after renal angioplasty, it is pertinent to identify patients with renal artery stenosis. The aim of the present study was to evaluate both duplex ultrasound and captopril renography for detection of renal artery stenosis among hypertensive patients. METHODS: To avoid selection bias, all patients referred to our center for evaluation of renovascular hypertension were asked to participate in the study. Patients were examined by intra-renal duplex ultrasound (N = 121), measuring pulsatility index and acceleration of the blood flow during early systole. In 98 patients, 99mTc-DTPA captopril renography was performed in conjunction with duplex ultrasound. Renal angiography was performed in all patients regardless of the results of the noninvasive tests. RESULTS: The prevalence of renal artery stenosis was 19%. In the 98 patients examined by both duplex ultrasound and captopril renography, sensitivity and positive predictive values for detection of a renal artery stenosis of 50% degree or more were 84 and 76%, respectively, for duplex ultrasound, whereas captopril renography was associated with a sensitivity and positive predictive value of 68% for both (P = NS). Specificity and negative predictive values were 94 and 96%, respectively, for duplex ultrasound, whereas the corresponding values for captopril renography were 92% for both (P = NS). Specificity and negative predictive values were 94 and 96%, respectively, for duplex ultrasound, whereas the corresponding values for captopril renography were 92% for both (P = NS). CONCLUSIONS: Both duplex ultrasound and captopril renography are associated with high specificity and negative predictive values for detection of renal artery stenosis. Sensitivity and positive predictive values are at least as good for duplex ultrasound compared with captopril renography. Given that duplex ultrasound is easier to perform and more cost effective, we propose that it should be the method of first choice when screening for renal artery stenosis in a hypertensive population.     

Renovascular disease and renal insufficiency--diagnosis and treatment

Renovascular disease as cause of end-stage renal disease has become more frequent during the last decade. In order to minimize the need for dialysis treatment non-invasive screening for the disease is needed. However, both ultrasonic duplex scanning and renal scintigraphy are not sufficient for detection of all stenosis. Furthermore, there is little data on non-invasive tests in patients with renal insufficiency. Renal arteriography is the gold standard for detection of renovascular disease. One disadvantage is the risk of contrast-agent induced acute renal insufficiency. This problem can be avoided using carbon dioxide angiography. In the near future spiral computed tomography and magnetic resonance angiography may be alternatives for identifying patients with renovascular disease. Ischaemic nephropathy is potentially curable. Percutaneous transluminal renal angioplasty is first line treatment in most cases. Intervention often results in improvement or preservation of renal function which is very important in order to avoid chronic dialysis.     

Follow-up of renal artery stenosis by duplex ultrasound

We have previously shown that duplex ultrasound is an accurate method of diagnosing renal artery stenosis (93% accuracy compared with angiography in the diagnosis of less than 60% stenosis, 60% to 99% stenosis, or occlusion). With this method we have now serially observed 35 renal arteries with 60% to 99% renal artery stenosis in 27 patients. Nineteen stenotic renal arteries in 15 patients were observed without intervention. There was a significant decrease in kidney size (mean difference - 1.0 cm; p less than 0.01; mean follow-up 13 months) but all 19 renal arteries remained patent. Percutaneous transluminal angioplasty (PTA) was performed in five patients (six renal arteries) for renovascular hypertension. Renal duplex scanning documented relief of renal artery stenosis in two patients whose hypertension improved after PTA and confirmed residual 60% to 99% renal artery stenosis in three patients whose hypertension did not improve after PTA (mean follow-up 6.5 months). Aortorenal bypass was performed for 10 stenotic renal arteries in seven patients. At a mean follow-up of 9 months duplex ultrasound documented eight patent and two occluded aortorenal bypass grafts. Duplex ultrasound is useful both for defining the natural history of untreated renal artery stenosis and assessing the results of renal artery angioplasty or bypass.     

Diagnostic procedure in renovascular hypertension

Detection of a renal artery stenosis (RAS) as a cause of arterial hypertension is of great practical importance because dilatation of the stenosis frequently results in an improvement or cure of the hypertension. In recent years, a number of screening procedures aimed at diagnosing renovascular hypertension have been developed, e.g., duplex sonography of the renal arteries, determination of plasma renin activity, or renal scintigraphy following administration of captopril. The possibilities and limitations of these screening procedures are described here. The best method for detecting renal artery stenosis is angiography, which can now be performed on an outpatient basis, using thin catheters.     

Imaging modalities for renal artery stenosis in suspected renovascular hypertension: prospective intraindividual comparison of color Doppler US, CT angiography, GD-enhanced MR angiography, and digital substraction angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Imaging Modalities for Renal Artery Stenosis in Suspected Renovascular Hypertension: Prospective Intraindividual Comparison of Color Doppler US,CT Angiography,GD-Enhanced MR Angiography,and Digital Substraction Angiography

The aim of the study was to evaluate the diagnostic accuracy of Color Doppler US, CT Angiography (CTA), and GD-enhanced MR Angiography (MRA) compared with digital subtraction angiography (DSA) for the detection of renal artery stenosis in patients with clinically suspected renovascular hypertension. Fifty-eight patients with suspected renovascular hypertension were enrolled in the study. All patients underwent Color Doppler US, CTA and GD-enhanced MRA. DSA was the gold standard method for the number of renal arteries, existence and degree of stenosis, or evidence of fibromuscular dysplasia. DSA depicted 132 renal arteries, 16 stenoses, and 4 arteries with fibromuscular dysplasia. Color Doppler US failed to detect 1 main and 14 polar arteries. CTA depicted all main renal arteries and 7/16 polar arteries, but failed to detect stenosis in two accessory vessels. Likewise, MRA did not detect stenotic accessory renal arteries, depicted 9/16 polar renal arteries, but missed two main renal arteries. All methods depicted the four main renal arteries with fibromuscular dysplasia. The overall sensitivity, specificity, and positive and negative predictive accuracy were 75%, 89.6%, 60% and 94.6%, respectively, for color Doppler US; 94%, 93%, 71%, and 99%, respectively, for CTA; and 90%, 94.1%, 75%, and 98%, respectively, for GD-enhanced MRA. CTA and GD-enhanced MRA have comparable and satisfactory results with respect to the negative predictive accuracy of the suspected renal artery stenosis. The concept of an imaging algorithm including US as screening test when appropriate and CTA or MRA as the second step-procedure is suggested. Therefore, DSA may be reserved for cases with major discrepancies or therapeutic interventions.     

Postoperative follow-up of renal artery reconstruction with duplex ultrasound

We evaluated the accuracy of duplex ultrasound in the postoperative follow-up of patients after renal revascularization. Between May 1976 and December 1987, 125 adult patients underwent 153 renal reconstructive procedures for renovascular occlusive disease. Technically satisfactory duplex scans were obtained in 49 of 59 patients (84%) at an average follow-up of 32 months (maximum 11 years). Arteriograms were available for correlation in 51 arteries or bypasses in 36 patients. Duplex scans accurately classified 8 of 10 stenotic (greater than 60% diameter reduction) or occluded vessels and 36 of 41 patent vessels. The overall diagnostic accuracy was 86%, sensitivity was 80%, and specificity was 87%. We confirmed previous reports that decreased diastolic flow correlated with advanced renal parenchymal dysfunction. We conclude that a normal duplex scan makes it highly unlikely that arteriography will reveal significant recurrent disease. An abnormal duplex scan, particularly in the presence of hypertension or deteriorating renal function, warrants arteriography.     

Treatment of renal artery fibromuscular dysplasia with balloon angioplasty: a prospective follow-up study.

OBJECTIVES: to assess restenosis rates and blood pressure response after percutaneous transluminal renal angioplasty (PTRA) in patients treated for fibromuscular dysplastic renal artery stenosis. METHODS: a prospective 12-month follow-up study of 27 patients with 31 treated renal artery stenosis. Follow-up assessment included colour-coded duplex sonography (CCD) of renal arteries, monitoring of blood pressure, antihypertensive medication, and creatinine measurements before discharge and at 3, 6, and 12 months. Primary end point was defined as a haemodynamically significant restenosis >60% assessed by CCD. RESULTS: there was a cumulative 23% restenosis rate at 12 months. Arterial hypertension was cured or improved in 93% of patients immediately after the intervention and remained cured/improved in 74% of patients at 12 months of follow-up. Renal failure present in five patients before PTRA stabilised or improved in all patients. CONCLUSION: although restenosis rate after PTRA in fibromuscular dysplasia is as high as in non-ostial atherosclerotic lesions, there remains a considerable higher therapeutic effect. Profound pressure response and recurrent arterial hypertension with restenosis support the high probability of a renovascular origin of arterial hypertension in this young and otherwise healthy population compared to patients with atherosclerotic renal artery lesions.     

Imaging techniques in the evaluation of pediatric hypertension

Moderate or severe hypertension occurs in a small percentage of hypertensive children, but it is within this group that the surgically correctable causes of hypertension are found. Since cure rates up to 90% have been reported, it is important to diagnose a secondary cause of hypertension. Excretory urography is recommended to screen for renovascular hypertension and renal parenchymal disease. Renal scintigraphy can be substituted for the urogram, but the anatomical resolution is poorer. If renovascular hypertension is suggested by abnormal results of screening examination, arteriography should be part of the evaluation. Ultrasonography is reserved primarily for evaluating neonatal hypertension which most frequently is related to thrombosis. If this diagnosis is documented, renal function should be assessed with radionuclide techniques. If a hormonally active tumor is suspected, evaluation of the adrenals and retroperitoneum is accomplished best by CT.     

Surgery of the renal arteries

Hypertension is a pervasive disease affecting between 10% and 15% of the population. Hypertension is manifested silently by an accelerated rate of atherosclerosis leading to increased incidence of cardiovascular, cerebrovascular, and peripheral vascular morbidities and deaths. Through activation of the renin-angiotensin axis, renovascular disease (RVD) accounts for approximately 5% of this hypertensive population. Recently, the relationship between renovascular occlusive disease and progressive renal insufficiency has been delineated and termed ischemic nephropathy. Patients with ischemic nephropathy present with hypertension in conjunction with elevated serum creatinine. It has been estimated that 15% of patients initiating dialysis each year have renovascular disease as the origin of their renal dysfunction. Renal dysfunction is due to a global reduction in renal perfusion, most often as a result of bilateral renal artery occlusive disease, although a mild form of renal insufficiency can be brought on by unilateral occlusive disease due to the effects of the renin-angiotensin system on the contralateral kidney. Historically, treatment of RVD has been centered on interrupting the renin-angiotensin axis and curing the resultant hypertension and its associated morbid disease. Currently, repair efficacy has been realized with concurrent retrieval of excretory renal function and cure of renovascular hypertension.      

Renovascular operations in patients with chronic renal insufficiency: do the benefits justify the risks?

To define the benefits and risks of renal revascularization or nephrectomy in patients with both severe hypertension and chronic renal insufficiency, we analyzed 98 patients who underwent renovascular operations after serum creatinine levels exceeded 2 mg/dl. This subset of patients was selected from a retrospective review of 652 renal operations performed at the Mayo Clinic for renovascular disease between 1970 and 1981. Special attention was given to the type of operations, their effect on hypertension and renal function, specific factors that affected operative deaths, and late survival. Unilateral renal operations were performed in 48 patients with bilateral procedures in 50. Simultaneous aortic reconstruction was necessary in 55 patients (56%). Postoperative diastolic blood pressure was less than 90 mm Hg in 55% of patients and 90 to 100 mm Hg in an additional 33%. Seventy-six percent of patients required less antihypertension medication. Serum creatinine improved or stabilized in 69%. Ninety percent of patients avoided any early or late renal dialysis. The operative mortality rate was 7.1% and tended to be higher in patients with a serum creatinine greater than 3 mg/dl and in those with past myocardial infarction (p = 0.05). The late survival rate was 64% at 5 years. The main cause of operative and late death was myocardial infarction. In conclusion, most patients with renovascular hypertension and early chronic renal insufficiency can be benefited by surgical revascularization or nephrectomy. Future improvement in early and late survival may require a more aggressive approach to the identification and correction of significant coronary artery disease.     

Erkrankungen der Nierenarterien

Renal artery diseases are rare, but seen more often in the last years due to demographic changes and increasing non invasive diagnostics. There are different types of pathologies involving the renal arteries. The clinical manifestation is mostly hypertension or renovascular insufficiency. The main indication for endovascular therapy is hypertension, especially in young patients with fibromuscular stenosis and in elderly patients with progressive atherosclerotic stenosis with severe hypertension. The surgical therapy is left for complex reconstructions, for aneurysm resection and for simultaneous renal and aortic revascularizations in elderly patients with a high comorbidity. The indication for surgical therapy is mostly renovascular insufficiency or rather organ preservation. The different therapeutic procedures, endovascular or surgical, are demonstrated according to outcome, complications and evidence.     

Renovascular hypertension in children: current concepts in evaluation and treatment

Since 1981, we have evaluated and treated 22 children with renovascular hypertension (RVH). Seventeen patients had stenosis of their native renal arteries, and five had stenosis of the artery in a transplanted kidney. RVH was caused by fibromuscular dysplasia in 13 patients, by trauma in 2 patients, and by arteritis in 2 patients. Among the patients who had transplanted kidneys, three had technical causes for stenosis and two had stenosis due to rejection. The disease was unilateral in 10 patients, bilateral in 5, and present in a solitary kidney in 7, including the five renal transplants. Diagnostic studies that strongly suggested the presence of renovascular disease were an initial diastolic blood pressure greater than 100 mm Hg, an elevated peripheral vein renin activity level, and an abnormal renal scan if the patient's hypertension was being controlled with an angiotensin-converting enzyme inhibitor (ACEI). Only the renal arteriogram was 100% accurate in confirming the presence of RVH. Percutaneous angiographic correction was attempted in 13 patients and resulted in lasting improvement of the hypertension in five (38%). Surgical revascularization was attempted in 17 children, including the 8 with failed angioplasty, with improvement or cure of the hypertension in 15 patients (88%). Combining percutaneous transluminal angioplasty (PTA) and surgical results gave 20 of 22 patients (91%) with cure or improvement of their hypertension. Four of 27 affected kidneys (15%) could not be revascularized and were removed. We conclude from this series of patients that despite improvements in noninvasive studies, renal arteriogram remains the only study that is 100% accurate in evaluating children for RVH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Management of renovascular hypertension in the elderly population

This article summarizes our experience with the operative management of renovascular hypertension in a contemporary population of elderly patients. During a recent 18-month period 35 of 74 patients (47%) undergoing an operation for renovascular hypertension at our center were in their seventh (21 patients) or eighth (14 patients) decade of life (mean age, 68 years). There were 17 men and 18 women with blood pressures ranging from 176/90 mm Hg to 280/215 mm Hg (mean, 213/121 mm Hg). Twenty-seven patients (77%) had renal insufficiency (serum creatinine greater than or equal to 1.3 mg/dl). Nineteen patients had severe insufficiency (serum creatinine greater than or equal to 2.0 mg/dl), with five of these patients being dependent on dialysis. Thirty-three of 35 patients (94%) had evidence of organ-specific atherosclerotic damage as manifested by cardiac disease (72%), cerebrovascular disease (37%), or renal insufficiency (77%). Operative management consisted of unilateral revascularization in 17 patients (includes three contralateral nephrectomies), bilateral renal revascularization in 17 patients, and primary nephrectomy in one. Simultaneous aortic replacement was performed in nine patients. There were two operative deaths (5.7%) and two postoperative graft thromboses (4%). Hypertension was cured (three) or improved (27) in 30 of the 33 survivors (91%). Renal function was improved in six and worsened in two patients with severe non-dialysis-dependent renal insufficiency. Three of five patients who were dependent on dialysis before surgery were removed from dialysis after renal revascularization. On follow-up (mean, 10.3 months) we found that five patients had died. This article emphasizes the complexity of atherosclerosis in the current population presenting for operative management of renovascular hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)     

Renal artery stenosis treated with stent deployment: indications, technique, and outcome for 108 patients

From January 1993 to May 1996, 108 patients (64 men, 44 women; mean age, 72 years; age range, 37 to 87 years) underwent 125 percutaneous transluminal angioplasties and stent implantations primarily for atherosclerotic lesions of the renal artery. Sixty-four patients underwent treatment for renovascular hypertension (two antihypertensive medications or more), 32 patients underwent treatment for a combination of hypertension and renal failure (serum creatinine level >/=1.6 mg/dL), and a small group of six patients (5%) without hypertension or diminished renal function underwent treatment to prevent the progression to renal artery occlusion and kidney loss. Thirty-three patients (31%) had renovascular hypertension that was classified as severe on three or more medications, 31 patients (29%) had renovascular hypertension that was classified as moderate on two medications, and 38 patients (35%) had renovascular hypertension that was classified in the mild group on a single antihypertensive agent. Stenotic lesions were located at the ostium of the renal artery in 82 cases (65%) and were ostial-adjacent (<5 mm from renal ostium) in the other 43 cases (34%). A total of 125 stents were deployed in 125 arteries (procedural success 97.6%). Renovascular hypertension either was cured or was improved in 73 patients (68%), with 14 patients (13%) considered cured (normotensive on no medications). The conditions of 29 patients (27%) were unchanged, and 6 patients (5%) had worsening hypertension after surgery. We were unable to demonstrate a statistically significant improvement in serum creatinine levels after renal artery balloon angioplasty/stenting. Complications occurred in a total of nine cases (7.2%), six of which were related to technical problems. One patient had worsening renal insufficiency caused by contrast agent, and another patient had a perinephric hematoma develop that necessitated evacuation. There were four postoperative deaths (30-day mortality). Two of these deaths were caused by postoperative myocardial infarction. The other two patients had progressive renal failure develop that necessitated dialysis. These patients later died of the disease process despite supportive care. Follow-up renal artery duplex scan studies and angiograms were available on 96 patients (76%). The mean peak systolic renal/aortic ratio on duplex scanning was 2.2. Life-table analysis yielded a 74% primary patency rate and an 85% secondary patency rate at 36 months. This retrospective analysis showed the effectiveness of combining percutaneous transluminal angioplasty with stent deployment for significant renal artery stenosis to treat renovascular hypertension.