Evaluation and management of bilateral renal artery stenosis in children: A case series and review

This report describes the clinical course, diagnostic evaluation and management of six children with bilateral renal artery stenosis (RAS) and concurrent narrowing of the abdominal aorta. Except for one child with active arteritis, the others were asymptomatic. There were no clinical or laboratory features suggesting the etiology of hypertension in four of six patients, and diagnostic procedures, including Doppler duplex ultrasound and captopril scintigraphy, were unreliable in screening for such hypertension. Abdominal aortography and selective renal angiography confirmed the diagnosis of bilateral RAS and associated anatomical alterations of the aorta and its branches. The hypertension was severe and minimally responsive to antihypertensive agents. It was cured or improved after percutaneous transluminal angioplasty (PTA) of three vessels in two children with mid-vessel stenoses, while hypertension persisted after PTA of two mid-vessel stenoses in a third child and one vessel with ostium stenosis in a fourth child. Autotransplantation of seven kidneys in four children resulted in cure or significant improvement of the hypertension. Renal function was preserved in all children during a mean follow-up time of 41 months. Based on illustrative data from these six children, as well as information from a review of the literature, this report discusses the key diagnostic issues and stresses the potential advantages of renal autotransplantation in selected children with this disorder.     

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.     

Renal artery stenosis: evaluation with colour duplex ultrasonography

Background: Detection of renal artery stenoses (RAS) by means of duplex Doppler ultrasound with direct scanning of the main renal arteries is subject to numerous limitations. Using semiquantitative analysis of the Doppler curve, which can be recorded from intrarenal arteries, it is possible to detect RAs unaffected by the problems of direct Doppler scanning of the renal arteries. Method: Both angiography of the renal arteries and colour duplex ultrasonography (US) of the intrarenal vessels (interlobar arteries) were performed in 214 patients (53.2±15.1 years) with severe arterial hypertension. Angiography was used as 'gold standard' in the diagnosis of RAS and the Doppler results were compared with the subsequent findings on angiography. At angiography, the reduction of diameter >70% was assessed as haemodynamically effective RAS. For the duplex Doppler diagnosis of RAS the following parameters were calculated: (a) resistive index (RI) of each kidney, and (b) side-to-side differences of the resistive indices (&Dgr;RI) between the right and left kidney. Results: Angiography demonstrated 59 RAS (>70%) in 53 patients, including six with bilateral RAS. By means of duplex US we found a significant difference of RI between kidneys with RAS (0.48±0.11) and without RAS (0.63±0.08; P<0.001). In addition, a significant difference of the &Dgr;RI was noted in patients with RAS (24.4%±12.5%) and the controls without RAS (3.6%±2.7%). Using a combination of both RI and &Dgr;RI, threshold values of RI=0.45 resp. &Dgr;RI=8% yields a sensitivity of 92.5% and a specificity of 95.7% in the detection of haemodynamically effective RAS. Conclusion: Colour duplex US with calculation of the RI and &Dgr;RI of intrarenal arteries is a valuable non-invasive test assessing the haemodynamic effects of RAS. Low costs and safety support the use of the Doppler technique in screening for renovascular disease.     

Two cases of atherosclerotic renal artery stenosis treated by percutaneous transluminal renal angioplasty and intravascular stent placement, leading to improvement of hypertension and renal function

We describe here two cases of renal artery stenosis(RAS) caused by atherosclerosis. Both patients were treated by percutaneous transluminal renal angioplasty(PTRA) and stent placement, leading to the improvement of renal function as well as hypertension. The two patients were a 75-year-old male(case 1) and a 56-year-old male(case 2), who both showed mild proteinuria, renal dysfunction, and refractory hypertension. Case 1 showed a unilateral ostial stenosis in the left main renal artery. On the other hand, case 2 showed an ostial stenosis in the left renal artery and a widespread narrowing in the right renal artery. After evaluation of the lesions by renal Doppler sonography, renogram, magnetic resonance signal intensity, and magnetic resonance angiography(MRA), each stenosis was treated by balloon angioplasty and intravascular stent placement without any major complications. Thereafter, in addition to hypertension, renal function also ameliorated significantly, and has remained stable for more than 12 months. Non-invasive screening tests and appropriate therapy for renovascular lesion should be considered in the case of elderly patients with refractory hypertension and progressive renal dysfunction, since ischemic nephropathy is increasing as a common cause of end stage renal disease and is showing favorable outcomes of revascularization.     

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.     

Captopril renal scintigraphy--an advance in the detection and treatment of renovascular hypertension

Despite the risks associated with renovascular hypertension and the durable benefits of revascularization, the detection of patients with renovascular hypertension and the selection of those who will benefit from interventional therapy remains a challenge. We have previously documented the reliability of captopril renal scintigraphy in predicting angiographically significant renal artery stenosis in patients suspected of having renovascular hypertension. In the present study we report our recent experience with this noninvasive technique in predicting outcome after revascularization. Captopril renal scintigraphy involves the administration of 50 mg of captopril 3 hours after a baseline technitium-99m diethylenetriaminepentaacetic acid renal scan and 1 hour before a repeat captopril renal scintigraphy scan. Nineteen of the last 70 patients with clinically suspected renovascular hypertension undergoing captopril renal scintigraphy had abnormal renal scan outcomes, and 17 had a decrease in flow or function after captopril (positive captopril renal scintigraphy). Eight of these 17 with abnormal findings on captopril renal scintigraphy underwent revascularization, and the hypertension was cured or improved in six of the eight: two of three after surgical bypass grafting and four of five after angioplasty. In the seven surviving patients with abnormal renal scan results but no change with captopril (negative captopril renal scintigraphy), improvement in hypertension after treatment occurred in only one: one of two after nephrectomy, zero of three after bypass surgery, and zero of two after angioplasty (p less than 0.05). We conclude that captopril renal scintigraphy is an accurate predictor of hypertension response to revascularization. Further evaluation of this new noninvasive technique for assessing patients with suspected renovascular hypertension appears warranted.     

Angiotensin-converting enzyme inhibitor renography in the diagnosis of renovascular hypertension. Studies before and after angioplasty.

Renography with [99mTc] diethylenetriaminepenta-acetate (DTPA) was performed in 26 patients with renal artery stenosis (RAS), unilateral in 15 and bilateral in 11, and in 16 patients with essential hypertension with a normal renal angiogram. Nine of the patients with unilateral RAS were restudied after a successful percutaneous transluminal renal angioplasty (PTRA), i.e. complete removal of the stenosis and a normalization of the blood pressure without antihypertensive treatment. Single-kidney [99mTc]-DTPA clearance and parenchymal mean transit time (MTT) were determined at each examination. All patients were studied on two different days using the same procedure except that captopril 25 mg was given orally before renography at the second examination. In unilateral RAS captopril reduced single-kidney [99mTc]-DTPA clearance significantly on the affected side (-42.7%, median) but not on the unaffected side (-3.2%). In bilateral RAS single-kidney [99mTc]-DTPA clearance was reduced to the greatest extent on the most affected side (-43.0%) compared with the least affected side (-17.2%). In essential hypertension no significant changes were recorded on any side (-1.5% for both). After PTRA, single-kidney [99mTc]-DTPA clearance was not significantly changed by captopril either on the previously affected side (4.3%) or on the unaffected side. MTT was significantly prolonged after captopril on the affected side in unilateral RAS and on the most affected side in bilateral RAS, whereas no significant changes were found on the unaffected side in unilateral RAS, on the least affected side in bilateral RAS, or on any side in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)     

Angioplasty of the renal artery: antihypertensive and renal effects

Percutaneous transluminal angioplasty of the renal artery (PTRA) has been increasingly used over the past 20 years for treating renovascular hypertension (RVH). From the experience gathered so far it is justified to state that this technique is the first choice for patients with fibromuscular renal artery stenosis (RAS) because their cure rate is 50% and 42% improve. In contrast in patients with atherosclerotic RAS the cure rate after PTRA is 8-10% although 40-50% still improve. Since PTRA is associated with a 23% rate of major/minor complications and 30% restenosis (23% requiring stent implantation), it is obvious that in patients with atherosclerotic RAS the decision to attempt this procedure must be taken after careful selection of those who may actually benefit from the dilation. PTRA can be used more extensively for salvaging the function of the ischemic kidney than for treating hypertension because of the progressive nature of the atherosclerotic RAS and the lack of effective agents against such progression. After PTRA 35% of patients have some improvement in renal function and another 35% are stabilized. Yet most studies addressing the renal effects of PTRA suffer the limitation of having used serum creatinine levels as an indicator of glomerular filtration rate (GFR). More recent studies which used radioisotopic techniques to evaluate the changes of GFR induced by PTRA in the stenotic kidney indicate that after a successful procedure the increase is, on average, 8-10 ml/min. Interestingly it appears that this improvement is slower in kidneys of patients with atherosclerotic RAS than in those with fibromuscular RAS.     

Clinical and duplex ultrasound follow-up after balloon angioplasty for atherosclerotic renal artery stenosis.

The purpose of this study was to investigate changes in blood pressure and renal function after percutaneous renal artery balloon angioplasty in hypertensive patients with atherosclerotic renal artery stenosis. Renal artery lesions were assessed by duplex ultrasound before and after renal artery balloon angioplasty. Renal arteries were classified as normal, < 60% stenosis, > or =60% stenosis, and occluded according to previously validated duplex criteria. Data regarding risk factors for atherosclerosis and years of hypertension were collected. Systolic and diastolic blood pressure, creatinine, and number of medications were obtained before and after intervention. The immediate technical outcome of renal artery angioplasty was classified based on the arteriographic result as follows: success (residual stenosis < or =30%), partial success (residual stenosis 31-50%), or unsuccessful (residual stenosis > 50%). For bilateral procedures, success required both renal arteries to be classified as technical successes; a technical success on one side only was classified as partial success. The blood pressure response to intervention was classified as follows: cure (diastolic blood pressure < or =95 mm Hg on no medications), improved (control of blood pressure with a significant reduction in number of medications or control of previously elevated blood pressure without a change in medications), or failed (all other responses). The study group included 28 patients (14 men, 14 women) with a mean age of 65 years. The preintervention and the first postintervention evaluations occurred within 180 days of the procedure. All patients were hypertensive, and all except one were under medical treatment. Mean duration of hypertension was 9.1 +/-8.8 years. There were 38 interventional procedures (28 unilateral, 10 bilateral) involving 41 renal arteries; seven arteries had two procedures done. Before angioplasty, all renal arteries had lesions of > or =60% diameter reduction by duplex scanning. Endovascular stents were deployed following angioplasty in 14 (34%) of the procedures. The technical result was classified as a success in 24 (63%), a partial success in 12 (32%) of the procedures, and two procedures (5%) were classed as technical failures. There were statistically significant reductions in blood pressure following successful and partially successful procedures, but cure of hypertension was achieved in only 11% of cases. There were no significant changes in creatinine in any of the technical result groups. Of the 38 renal arteries evaluated with duplex ultrasound following intervention, 39% were found to have stenosis of > or =0% involving a treated renal artery, including one postintervention occlusion. Cure of hypertension was rare in this patient population with atherosclerotic renal artery stenosis. More than one third of the treated renal arteries showed > or =0% lesions recurring after the procedure. Thirteen percent of those with technical success and 17% of those with partial technical success had creatinine improvement of at least 20% over the baseline value. Significant clinical and anatomic improvement were relatively uncommon following balloon angioplasty in this series of patients.     

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.     

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.     

肾动脉狭窄的介入治疗分析

目的 分析介入治疗肾动脉狭窄（RAS）的疗效。方法自2003年3月至2008年3月共收治45例RAS患者,53支肾动脉中单纯行腔内球囊扩张术（PTA）治疗11支,行球囊扩张及内置支架术（PTA／Stent）治疗者42支,随访9～48个月,检测患者的血压与血肌酐水平,并作肾动脉彩超。结果手术成功率为100％。手术后高血压治愈者9例,改善28例,肾功能改善12例。肌纤维发育不良及多发性大动脉炎的血压改善有效率均为100％,高于动脉粥样硬化的有效率65．1％（P〈0．05）。行彩色多普勒超声检查肾动脉18支,发现再狭窄者7支。结论PTA和PTMStent治疗肾动脉狭窄具有微创、安全、有效的优点。     

Noninvasive radiological diagnosis of renal vein thrombosis in renal transplantation.

Thrombosis of the allograft renal vein is a rare complication of renal transplantation. Of 557 consecutive renal transplants performed between January 1, 1985 and November 30, 1989, 3 cases occurred for an over-all incidence of 0.4%. In 2 cases the diagnosis was made preoperatively with renal scintigraphy and duplex Doppler sonography. No graft was salvaged, despite timely diagnosis in 2 patients. We conclude that the diagnosis of renal vein thrombosis in the renal allograft recipient should be suspected clinically and by the radiographic findings of absent perfusion on renal scintigraphy, and the detection of an arterial signal, albeit abnormal, on duplex Doppler sonography. When diagnosed, nephrectomy appears to be the only treatment.     

Captopril-enhanced scintigraphy using the method of the expected renogram: improved detection of patients with renin-dependent hypertension due to functionally significant renal artery stenosis

Purpose and design of study: Asymmetric-induced changes of the renogram under angiotensin-converting enzyme inhibition (ACE-I), i.e. lateralization, is probably the most distinctive finding for the detection of haemodynamically significant renal artery stenosis (RAS) in compensated kidney, since bilateral and symmetric patterns are non-specific. In the Consensus statement of diagnostic criteria of renovascular hypertension with captopril renography (Am J Hypertens 1991; 4: 749-755S) ACE-I-induced asymmetry of renograms for the left and right kidney was viewed as vitally important. However, detection of change in split function is a reliable parameter only when using a glomerular tracer, i.e. ^99mTc-DTPA. No indication regarding a more widely used tubular tracer such as ^99mTc-mercaptoacetyltriglycine (^99mTc-MAG3) has been given. Methods and results: the theoretical contralateral curve, called 'expected renogram', was calculated frame by frame from renal curves obtained under ACE-I and one of two baseline curves. The expected renogram was compared with the recorded ipsilateral curve. More than ±2 SD difference between expected and recorded renograms was assumed as suggestive of monolateral or bilateral RAS. Twenty-nine patients with angiographically proven RAS (bilateral in 12) and 20 patients without arteriographic evidence of stenosis were evaluated by post-captopril/baseline ^99mTc-MAG3 renography results obtained with the expected renogram analysis were compared with those obtained by standard criteria which included: improvement of peak time underbase-line conditions, wash-out (75%) time, and monolateral or bilateral residual cortical activity >10%, but asymmetrical, i.e. with >5% change in split function. Compared to the standard evaluation, the use of the expected renogram for the diagnosis of RAS improved the specificity from 70 to 95% (P<0.03) without loss of sensitivity (79.3%). Follow-up data after revascularization were available in 18 scintigraphically positive and six scintigraphically negative patients with RAS. The sensitivity of the expected renogram method referring to short-term (1 month) patient outcome following revascularization was 88.8%. The beneficial effects on blood pressure response persisted in 77% of these patients at 18 months. Notably, four of six scintigraphically negative patients with RAS did not show any short-term benefit from revascularization and the improvement in blood pressure values lasted for 18 months in only one case. Conclusions: The high specificity of the expected renogram method reduces the number of unnecessary invasive procedures. This is a critical point for a low-prevalence disease such as renovascular hypertension.     

Detection of significant renal artery stenosis with color Doppler sonography: combining extrarenal and intrarenal approaches to minimize technical failure

BACKGROUND: Renal artery disease can cause both hypertension and renal failure, and color Doppler sonography (CDS) may be a good screening method to detect it. Presently reported techniques of Doppler sonography have either a high rate of technical failure (4-42%), or low sensitivity and specificity, or detect only stenoses greater than 70%, or exclude patients with renal failure from analysis. In previous studies Doppler detection of renal artery stenosis (RAS) was based either on increased intrastenotic velocity or on the detection of post-stenotic Doppler phenomena. In the present prospective study these two approaches were combined to detect RAS (> or = 50% diameter reduction) in 226 consecutive patients (144 with normal and 82 with impaired renal function). METHODS: Stenosis of 50% or more was diagnosed if the maximal systolic velocity in the main renal artery was more than 180 cm/sec and velocity in the distal renal artery less than one quarter of the maximum velocity. When these velocities could not be determined a diagnosis of RAS was made when the acceleration time in intrarenal segmental arteries exceeded 70 msec. All patients subsequently underwent arteriography as the gold standard for the detection of RAS. RESULTS: With this combined approach, the technical failure rate of CDS was 0% in both patients with normal and those with impaired renal function. The mean time required for the Doppler investigation was 17 minutes. The sensitivity and specificity for detection of a significant stenosis in a given vessel (including accessory arteries), as compared to angiography, were 96.7% and 98.0%. CONCLUSION: Color Doppler sonography, evaluating both main renal and intrarenal arteries is an ideal screening method for detection of RAS of 50% or more because it allows accurate and rapid detection of stenosis in all patients, irrespective of renal function.     

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.     

Atherosclerotic renovascular disease: medical therapy versus medical therapy plus renal artery stenting in preventing renal failure progression: the rationale and study design of a prospective, multicenter and randomized trial (NITER)

BACKGROUND: Many studies suggest a major prevalence of atherosclerotic renovascular disease (ARVD), caused by mono or bilateral renal artery stenosis (RAS). Unfortunately, there is no definite therapy to cure this disease to date; therefore, ARVD is burdened by important clinical complications with high social and economic costs. The last few years have seen important advancements in both medical therapy and in interventional radiology (for example, percutaneous transluminal renal artery stenting (PTRS)). All of them could affect, in some way, the natural history of ARVD, but to date the optimal strategy has not been established. METHODS: The protocol of a prospective, multicenter, randomized trial "Nephropathy Ischemic Therapy (NITER)" is presented. It enrolls patients with stable renal failure (glomerular filtration rate (GFR) >or=30 ml/min) and hypertension, and hemodynamically significant atherosclerotic ostial RAS (>or=70%) diagnosed by duplex Doppler (DD) ultrasonography and confirmed by magnetic resonance angiography (MRA). This study aims to evaluate whether medical therapy plus interventional PTRS is superior to medical therapy alone according to the following combined primary endpoint: death or dialysis initiation or reduction by >20% in estimated GFR after 0.5, 1, and 2 yrs of follow-up and an extended follow-up until the 4th year. Medical therapy means drugs to control hypertension, improve dyslipidemia and optimize platelet anti-aggregant therapy. The sample size is estimated in 50 patients per group to achieve a statistical significance of 0.05 in case of a reduction by 50% in the combined endpoints.     

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.     

Ischemic nephropathy: proteinuria and renal resistance index could suggest if revascularization is recommended

Background: The aim of endovascular therapy in renal artery stenosis (RAS) is to preserve renal function and have a better hypertension control. The purpose of our study was to determine which biochemical and instrumental parameters could predict a better renal outcome in patients with RAS treated with percutaneous transluminal angioplasty and stenting (RPTAS). Methods: We performed an observational study based on 40 patients with RAS who met the following criteria before revascularization: urinary protein excretion of over 250 mg/24 h, normal renal function, and/or mild–moderate renal insufficiency (I, II, and III levels of classification of chronic kidney disease, K-DOQI). Results: Assessment at 12 months after RPTAS showed in 20 patients (Group A) that proteinuria serum creatinine (Scr) and creatinine clearance (CrCl) significantly worsened from the baseline; whereas in 20 patients (Group B) proteinuria remained unchanged and the renal function improved after the procedure. Conclusions: In our study, the decline of renal function after RPTAS is associated with an elevated renal resistance index (RI) in both kidneys (0.83 ± 0.2) and preexisting proteinuria.     

Should percutaneous transluminal renal artery angioplasty be applied to ostial renal artery atherosclerosis?

Purpose: The purpose of this study was to review the results of percutaneous transluminal renal artery angioplasty (PTRA) in patients with atherosclerosis to assess safety, anatomic and functional outcome, and differences in outcome between ostial and nonostial lesions.Methods: We used retrospective review of 52 consecutive patients who had undergone attempted PTRA for renal artery atherosclerosis during the calendar years 1987 to 1992.Results: Fifty-two patients had 60 renal arteries on whom PTRA was attempted. The mean age was 68 years. Atherosclerosis was generalized in 81% of the patients. The indication for angioplasty was salvage of functioning renal parenchyma in 81% of patients. Eight patients were undergoing dialysis at the time of attempted PTRA. Five arteries (8%) could not be dilated. There were one cardiac death and two arterial complications requiring surgery within 30 days. Thirty-five percent of patients with available angiograms had an anatomic improvement above a threshold of one stenotic group (30% to 40% diameter improvement), with residual stenosis of less than 50%. Half of patients treated for hypertension had improvement in their hypertension. Overall, there was no change in creatinine levels before and after the procedure. Four of eight patients undergoing dialysis at the time of PTRA were able to discontinue dialysis during follow-up. Four patients (11%) required surgical bypass and five patients (14%) required chronic dialysis during follow-up.Conclusions: Modest success at low risk can be expected from PTRA in a group of patients with severe atherosclerosis. No significant difference in results between ostial and nonostial lesions was noted. (J VASC SURG 1995;21:909-15.)