Renal artery stenosis: epidemiology and treatment

Trapdoor endarterectomy for coral reef plaque of the paravisceral aorta in the modern era

Coral reef atherosclerosis of the paravisceral aorta is a rare disease whose description is confined to before contemporary vascular surgical techniques. This study aims to describe the characteristics and outcomes of patients with coral reef aorta treated with trapdoor endarterectomy at a single high-volume quaternary referral center since 2010. From 2010 to 2022, 14 patients with coral reef aorta were treated with trapdoor endarterectomy. The patient data were obtained via a retrospective medical record review. The patients were predominantly women (79%) with a median age of 65 years (interquartile range [IQR], 60-70 years). The patients universally had a tobacco smoking history and hypertension. More than 85% had previously diagnosed carotid stenosis. Two patients (14%) had undergone prior aortofemoral reconstruction, and one patient (7%) had undergone prior axillobifemoral bypass. The most common presenting symptoms were claudication (71%), chronic mesenteric ischemia (50%), and renovascular hypertension (43%). Of the 14 patients, 8 (57%) underwent isolated endarterectomy and 6 (43%) underwent concomitant aortobifemoral bypass. In addition, 13 patients (93%) required a supraceliac aortic clamp position with a median clamp time of 23 minutes (IQR, 20-30 minutes). The median estimated blood loss was 1650 mL (IQR, 1025-3000 mL). A cell saver was used in 13 procedures (93%), with a median transfusion of 563 mL (IQR, 231-900 mL). The median operative time was 341 minutes (IQR, 315-416 minutes). Eight patients (57%) experienced acute kidney injury in the postoperative period with a peak creatinine of 1.96 mg/dL (IQR, 1.50-2.84 mg/dL). The median length of stay was 11 days (IQR, 6-16 days), with an intensive care unit stay of 4 days (IQR, 2-7 days). One patient (7%) required reoperation in the immediate perioperative period for a retroperitoneal hematoma. The postoperative ankle brachial index increased from a median of 0.58 (right) and 0.57 (left) bilaterally in the preoperative period to 1.09 (right) and 1.10 (left) postoperatively. Eight patients (57%) had follow-up data available for >2 years postoperatively, with five patients (36%) having follow-up data available for >3 years. Two major adverse cardiac events were reported at the last follow-up. One patient reported mild recurrent symptoms of chronic mesenteric ischemia during 3 years of postoperatively, with no concurrent imaging findings or loss of patency found on computed tomography angiography. Symptomatic coral reef atherosclerosis of the paravisceral aorta is a complex disease rarely encountered even at high-volume referral centers. These patients can be expected to experience short-term postoperative morbidity and require intensive care. Despite these challenges, trapdoor endarterectomy is a safe and effective procedure for coral reef aorta, and most patients achieve dramatic symptomatic improvement with durable results.

Renal artery involvement is associated with increased morbidity but not mortality in Takayasu arteritis: a matched cohort study of 215 patients

BACKGROUND

We analyzed differences in presentation and survival of Takayasu arteritis (TAK) with or without renal artery involvement (RAI) from a large monocentric cohort of patients with TAK.

METHODS

Clinical and angiographic features were compared between TAK with versus without RAI, with bilateral versus unilateral RAI, and with bilateral RAI versus without RAI using multivariable-adjusted logistic regression. Inter-group differences in survival were analyzed [hazard ratios (HR) with 95% confidence intervals (95%CI)] adjusted for gender, age at disease onset, diagnostic delay, baseline disease activity, and significant clinical/angiographic inter-group differences after multivariable-adjustment/propensity score matching (PSM).

RESULTS

Of 215 TAK, 117(54.42%) had RAI [66(56.41%) bilateral]. TAK with RAI or with bilateral RAI had earlier disease onset than without RAI (p < 0.001). Chronic renal failure (CRF) was exclusively seen in TAK with RAI. TAK with RAI (vs without RAI) had more frequent hypertension (p = 0.001), heart failure (p = 0.047), abdominal aorta (p = 0.001) or superior mesenteric artery involvement (p = 0.018). TAK with bilateral RAI (vs unilateral RAI) more often had hypertension (p = 0.011) and blurring of vision (p = 0.049). TAK with bilateral RAI (vs without RAI) more frequently had hypertension (p = 0.002), heart failure (p = 0.036), abdominal aorta (p < 0.001), superior mesenteric artery (p = 0.002), or left subclavian artery involvement (p = 0.041). Despite higher morbidity (hypertension, CRF), mortality risk was not increased with RAI vs without RAI (HR 2.32, 95%CI 0.61-8.78), with bilateral RAI vs unilateral RAI (HR 2.65, 95%CI 0.52-13.42) or without RAI (HR 3.16, 95%CI 0.79-12.70) even after multivariable adjustment or PSM.

CONCLUSION

RAI is associated with increased morbidity (CRF, hypertension, heart failure) but does not adversely affect survival in TAK. Key Points •Renal artery involvement in TAK is associated with chronic renal failure. •TAK with renal artery involvement more often have heart failure and hypertension. •Bilateral renal artery involvement (compared with unilateral) is more often associated with hypertension and visual symptoms. •Renal artery involvement is not associated with an increased risk of mortality in TAK.

Using Ultrahigh b -Value Diffusion-Weighted Imaging to Noninvasively Assess Renal Fibrosis in a Rabbit Model of Renal Artery Stenosis

OBJECTIVE

This study aimed to investigate the feasibility of diffusion-weighted imaging with ultrahigh b values ( ub DWI) for the evaluation of renal fibrosis (RF) induced by renal artery stenosis (RAS) in a rabbit model.

METHODS

Thirty-two rabbits underwent left RAS operation, whereas 8 rabbits received sham surgery. All rabbits underwent ub DWI ( b = 0-4500 s/mm 2 ). The standard apparent diffusion coefficient (ADC st ), molecular diffusion coefficient ( D ), perfusion fraction ( f ), perfusion-related diffusion coefficient ( D *) and ultrahigh apparent diffusion coefficient (ADC uh ) were longitudinally assessed before operation and at weeks 2, 4, and 6 after operation. The degree of interstitial fibrosis and the expression of aquaporin (AQP) 1 and AQP2 were determined through pathological examination.

RESULTS

In the stenotic kidney, the ADC st , D , f , and ADC uh values of the renal parenchyma significantly decreased compared with those at baseline (all P < 0.05), whereas the D * values significantly increased after RAS induction ( P < 0.05). The ADC st , D , D *, and f were weakly to moderately correlated with interstitial fibrosis as well as with the expression of AQP1 and AQP2. Furthermore, the ADC uh negatively correlated with interstitial fibrosis ( ρ = -0.782, P < 0.001) and positively correlated with AQP1 and AQP2 expression ( ρ = 0.794, P < 0.001, and ρ = 0.789, P < 0.001, respectively).

CONCLUSIONS

Diffusion-weighted imaging with ultrahigh b values shows the potential for noninvasive assessment of the progression of RF in rabbits with unilateral RAS. The ADC uh derived from ub DWI could reflect the expression of AQPs in RF.

Resveratrol Supplants Captopril's Protective Effect on Cardiac Remodeling in a Hypertension Model Elicited by Renal Artery Stenosis

Background: Renovascular hypertension elicits cardiac damage and remodeling. Two-kidney, one-clip (2K1C) is an experimental model used to study hypertension pathophysiology. In this model, the renin-angiotensin-system (RAS) is overactive due to renal artery stenosis, leading to cardiac remodeling. Redox mechanisms underlying RAS activation mediate hypertension-induced cardiovascular damage. Preclinical studies and clinical trials demonstrated resveratrol's protective effects in cardiovascular diseases, mainly attributed to its antioxidant properties. We hypothesized resveratrol alone or in combination with an angiotensin-converting enzyme (ACE) inhibitor would be beneficial against cardiac damage caused by renovascular hypertension. Objective: We investigated the benefits of resveratrol against cardiac remodeling in 2K1C rats compared with captopril. Methods: Male Wistar rats underwent unilateral renal stenosis - 2K1C Goldblatt model of hypertension. Systolic Blood Pressure (SBP) was measured before and 6 weeks after surgery. Hypertensive 2K1C rats presented SBP≥160 mmHg. From the 6^th week after the surgery, the animals received oral resveratrol (20 mg/kg), captopril (12 mg/kg), or their combination for 3 times per week for 3 weeks. Whole heart hypertrophy was evaluated. Histological assays assessed left ventricle hypertrophy and fibrosis. Results: Renovascular hypertension caused cardiac hypertrophy, accompanied by increased myocyte diameter and collagen deposition. Resveratrol reduced 2K1C rats' SBP and whole heart hypertrophy, independently of captopril. Resveratrol caused a higher reduction in ventricular hypertrophy than captopril. Collagen deposition was greater reduced by 2K1C treated only with resveratrol than with captopril alone or combined with resveratrol. Conclusion: Independent of captopril, resveratrol prompts cardioprotective effects on cardiomyocyte remodeling and fibrosis resulting from renovascular hypertension in 2K1C rats.

Is the Renal Resistive Index a Marker for Revascularization in Atherosclerotic Renal Artery Stenosis?

Renal artery stenosis (RAS) is one of the major causes of resistant/malignant hypertension. It can be described as atherosclerotic or non-atherosclerotic. Atherosclerotic RAS comprises almost 90% of all RAS cases and is a prevalent disease of the elderly. Multiple risk factors contribute to atherosclerosis development, which leads to the release of renin and aldosterone, causing resistant/malignant hypertension. Early recognition is prudent but challenging as there are no early clinical signs. We believe that renal resistive index with supportive clinical, laboratory, and imaging modalities can help select revascularization patients.

An Outline of Renal Artery Stenosis Pathophysiology-A Narrative Review

Renal artery stenosis (RAS) is conditioned mainly by two disturbances: fibromuscular dysplasia or atherosclerosis of the renal artery. RAS is an example of renovascular disease, with complex pathophysiology and consequences. There are multiple pathophysiological mechanisms triggered in response to significant renal artery stenosis, including disturbances within endothelin, kinin-kallikrein and sympathetic nervous systems, with angiotensin II and the renin-angiotensin-aldosterone system (RAAS) playing a central and key role in the pathogenesis of RAS. The increased oxidative stress and the release of pro-inflammatory mediators contributing to pathological tissue remodelling and renal fibrosis are also important pathogenetic elements of RAS. This review briefly summarises these pathophysiological issues, focusing on renovascular hypertension and ischemic nephropathy as major clinical manifestations of RAS. The activation of RAAS and its haemodynamic consequences is the primary and key element in the pathophysiological cascade triggered in response to renal artery stenosis. However, the pathomechanism of RAS is more complex and also includes other disturbances that ultimately contribute to the development of the diseases mentioned above. To sum up, RAS is characterised by different clinical pictures, including asymptomatic disorders diagnosed in kidney imaging, renovascular hypertension, usually characterised by severe course, and chronic ischemic nephropathy, described by pathological remodelling of kidney tissue, ultimately leading to kidney injury and chronic kidney disease.

Use of percutaneous transluminal renal angioplasty in atherosclerotic renal artery stenosis: a systematic review and meta-analysis

OBJECTIVE

For patients with atherosclerotic renal artery stenosis (ARAS), the role of percutaneous transluminal renal angioplasty (PTRA) remains inconclusive. This study aimed to comparatively evaluate the benefits of best medical therapy (BMT) plus PTRA and BMT alone in treating ARAS.

METHODS

We performed a systematic review and meta-analysis, and searched for all randomized, controlled trials that reported patients with ARAS. The effectiveness and safety in the BMT plus PTRA and BMT alone groups were estimated, taking into account hypertension, stroke, renal events, cardiac events, and mortality.

RESULTS

Nine randomized, controlled trials involving 2309 patients were included. In the BMT plus PTRA group, the incidence of refractory hypertension was significantly lower compared with that in the BMT alone group (odds ratio 0.09; 95% confidence interval 0.01, 0.70). However, there were no significant differences in the rates of stroke, renal events, cardiac events, cardiac mortality, and all-cause mortality between the two groups.

CONCLUSIONS

PTRA plus BMT improves blood pressure in patients with ARAS, but there is insufficient evidence for this therapy in improving stroke, renal events, cardiac events, and cardiac and all-cause mortality.

Excessive dietary salt promotes aortic stiffness in murine renovascular hypertension

Renovascular hypertension is characterized by activation of the renin-angiotensin-aldosterone system, blunted natriuretic responses, and elevated sympathetic nerve activity. Excess dietary salt intake exaggerates arterial blood pressure (ABP) in multiple models of experimental hypertension. The present study tested whether a high-salt diet exaggerated ABP and vascular dysfunction in a 2-kidney, 1-clip (2K1C) murine model. Male C57BL/6J mice (8-12 wk) were randomly assigned, and fed a 0.1% or 4.0% NaCl diet, and instrumented with telemetry units to measure ABP. Then, the 2K1C model was produced by placing a cuff around the right renal artery. Systolic, diastolic, and mean ABP were significantly higher in mice fed 4.0% vs. 0.1% NaCl at 1 wk but not after 3 wk. Interestingly, 2K1C hypertension progressively increased arterial pulse pressure in both groups; however, the magnitude was significantly greater in mice fed 4.0% vs. 0.1% NaCl at 3 wk. Moreover, pulse wave velocity was significantly greater in 2K1C mice fed 4.0% vs. 0.1% NaCl diet or sham-operated mice fed either diet. Histological assessment of aortas indicated no structural differences among groups. Finally, endothelium-dependent vasodilation was significantly and selectively attenuated in the aorta but not mesenteric arteries of 2K1C mice fed 4.0% NaCl vs. 0.1% NaCl or sham-operated control mice. The findings suggest that dietary salt loading transiently exaggerates 2K1C renovascular hypertension but promotes chronic aortic stiffness and selective aortic vascular dysfunction.NEW & NOTEWORTHY High dietary salt exaggerates hypertension in multiple experimental models. Here we demonstrate that a high-salt diet produces a greater increase in arterial blood pressure at 1 wk after induction of 2-kidney, 1-clip (2K1C) hypertension but not at 3 wk. Interestingly, 2K1C mice fed a high-salt diet displayed an exaggerated pulse pressure, elevated pulse wave velocity, and reduced endothelium-dependent vasodilation of the aorta but not mesenteric arteries. These findings suggest that dietary salt may interact with underlying cardiovascular disease to promote selective vascular dysfunction and aortic stiffness.

The Anatomy of Renal Arteries in Adults

Detailed extraparenhymal renal hilar dissection was performed on 110 fixed cadaveric kidneys (60 from male cadavers and 50 from female cadavers). We analyzed the number of renal arteries, angles between renal arteries and abdominal aorta, length and diameter of the renal arteries. Multiple renal arteries were present in 20.9% of cases, with a slightly higher incidence on the right side (21.8%: 20.0%). The angle between the aorta and the RRA varied from 30° to 100° with a mean of 64.1°, while the angle between the abdominal aorta and the LRA was 40° to 115°, with a mean of 67.3°. The external caliber of the RRA at the point of origin from the abdominal aorta was 5 mm to 9.1 mm, with a mean of 6.8 mm. The same caliber of the LRA was 3.7 to 9.6 mm with a mean of 7.0 mm. The average length of the renal artery from the point of origin from the abdominal aorta to the branching point was 36.2 mm for the right renal artery and 30.7 mm for the left renal artery. The average length of the renal artery from the point of origin from the abdominal aorta to the renal hilum was 65.1 mm for the right one and 54.7 mm for the left one. Knowledge of the number of renal arteries, their mode of entry into the kidney, the angles they build with the abdominal aorta, their diameter and length has practical applications in interventional radiology and surgery of the kidney and its environment.

Stenosis Indicators Applied to Patient-Specific Renal Arteries without and with Stenosis

Pulsatile flow in the abdominal aorta and the renal arteries of three patients was studied numerically. Two of the patients had renal artery stenosis. The aim of the study was to assess the use of four types of indicators for determining the risk of new stenosis after revascularization of the affected arteries. The four indicators considered include the time averaged wall shear stress (TAWSS), the oscillatory shear index (OSI), the relative reference time (RRT) and a power law model based in platelet activation modeling but applied to the endothelium, named endothelium activation indicator (EAI). The results show that the indicators can detect the existing stenosis but are less successful in the revascularized cases. The TAWSS and, more clearly, the EAI approach seem to be better in predicting the risk for stenosis relapse at the original location and close to the post-stenotic dilatation. The shortcomings of the respective indicators are discussed along with potential improvements to endothelial activation modeling and its use as an indicator for risks of restenosis.

The Metabolic Syndrome Does Not Affect Development of Collateral Circulation in the Poststenotic Swine Kidney

BACKGROUND

The collateral circulation is important in maintenance of blood supply to the ischemic kidney distal to renal artery stenosis (RAS). Obesity metabolic syndrome (MetS) preserves renal blood flow (RBF) in the stenotic kidney, but whether this is related to an increase of collateral vessel growth is unknown. We hypothesized that MetS increased collateral circulation around the renal artery.

METHODS

Twenty-one domestic pigs were randomly divided into unilateral RAS fed an atherogenic (high-fat/high-fructose, MetS-RAS) or standard diet, or controls (n = 7 each). RBF, glomerular filtration rate (GFR), and the peristenotic collateral circulation were assessed after 10 weeks using multidetector computed tomography (CT) and the intrarenal microcirculation by micro-CT. Vascular endothelial growth factor (VEGF) expression was studied in the renal artery wall, kidney, and perirenal fat. Renal fibrosis and stiffness were examined by trichrome and magnetic resonance elastography.

RESULTS

Compared with controls, RBF and GFR were decreased in RAS, but not in MetS-RAS. MetS-RAS formed peristenotic collaterals to the same extent as RAS pigs but induced greater intrarenal microvascular loss, fibrosis, stiffness, and inflammation. MetS-RAS also attenuated VEGF expression in the renal tissue compared with RAS, despite increased expression in the perirenal fat.

CONCLUSIONS

MetS does not interfere with collateral vessel formation in the stenotic kidney, possibly because decreased renal arterial VEGF expression offsets its upregulation in perirenal fat, arguing against a major contribution of the collateral circulation to preserve renal function in MetS-RAS. Furthermore, preserved renal function does not protect the poststenotic kidney from parenchymal injury.

Two-kidney one-clip is a pertinent approach to integrate arterial hypertension in animal models of stroke: Serial magnetic resonance imaging studies of brain lesions before and during cerebral ischemia

Although chronic arterial hypertension (CAH) represents the major comorbid factor in stroke, it is rarely integrated in preclinical studies of stroke. The majority of those investigations employ spontaneously hypertensive rats (SHR) which display a susceptibility to ischemic damage independent of hypertension. Here, we used a renovascular model of hypertension (RH) to examine, with magnetic resonance imaging (MRI), brain alterations during the development of hypertension and after brain ischemia. We also examined whether MRI-derived parameters predict the extent of ischemia-induced brain damage. RH was induced according to the two-kidney one-clip model and multiparametric MRI was performed at 3, 6, 9, and 12 weeks after hypertension and also at 10, 50, and 60 min following stroke. Blood pressure values increased progressively and reached a plateau at 6 weeks after RH induction. At 12 weeks, all hypertensive animals displayed spontaneous brain lesions (hemorrhages, deep and cortical lesions, ventricular dilatation), increased apparent diffusion coefficient (ADC) values in the corpus callosum and higher fractional anisotropy in the cortex. Following ischemia, these animals showed larger brain lesions (406 ± 82 vs. 179 ± 36 mm³, p < 0.002) which correlated with ADC values at chronic stage of hypertension. This model of hypertension displays many characteristics of the neuropathology of human CAH. The use of this model in stroke studies is relevant and desirable.

Unilateral renal artery stenosis presenting as acute flaccid paralysis: a rare presentation

Renovascular hypertension is one of the common causes of secondary hypertension. Here we report a case of patient of renal artery stenosis presenting to the emergency department as a case of acute flaccid paralysis. Renal artery stenosis has been associated with hypokalaemia, but rarely reported to be symptomatic. Initial correction of hypokalaemia leads to improvement of weakness and aetiological work up for hypokalaemia with hypertension revealed hypokalaemia due to hyperaldosteronism secondary to unilateral renal artery stenosis. The patient was managed medically with aldosterone antagonist in the anti hypertensive therapy and weakness did not recur despite withdrawal of potassium supplements. On follow-up, the patient was ambulatory with no signs of weakness, controlled blood pressure and normal potassium level.

Analysis of renal artery morphometery in adults: A study conducted by using Multidetector computed Tomography Angiography

Objective:

To determine a reference range of renal artery measurements by using Multidetector Computed Tomography (MDCT) angiography and to find association of renal artery measurements with side of artery, gender and age.

Method:

Two hundred and fifty study participants without renal artery disease who werepresented to Radiology Department, Ziauddin Hospital, Karachi, from November, 2016 to April, 2017 were included in this study. Main renal artery measurements were taken on Multidetector computed angiography and variation with side, gender and age were analyzed. Statistical analysis was done on Statistical Package for Social Sciences (SPSS) version 20. Independent sample T test, one way ANOVA and Pearson’s correlation analysis were applied. P-value of < 0.05 was considered significant.

Results:

A significance difference (p=0.001) was seen between mean right renal artery (diameter 6.66 ± 0.39 mm; length 44.69 ± 2.48 mm) and left renal artery (diameter 6.79 ± 0.36; length 35.10 ± 2.86 mm). Females found to have smaller mean diameter and length of renal arteries than males. However, a weak negative correlation was seen between mean renal artery diameter and age (right r= -0.158, p=0.0121; left r= -0.017, p= 0.708).

Conclusion:

The mean diameter and mean length were found to be significantly different between right and left main renal artery and between males and females. A significant weak negative correlation was observed between renal artery diameter and age.

Endovascular Treatment of Renal Artery Stenosis due to Fibromuscular Dysplasia - Is Stent Implantation Underused in this Circumstance?

Fibromuscular dysplasia (FMD) is a nonatherosclerotic and noninflammatory arterial disease that commonly affects the renal and carotid arteries. The primary target in treating patients with renal artery FMD is the control of blood pressure in order to prevent end-organ damage, which can be caused by poorly controlled hypertension. Invasive endovascular treatment should be taken into consideration both when hypertension cannot be controlled with medication. According to current opinion, hypertension attributed to renal artery FMD is often successfully treated solely with percutaneous renal balloon angioplasty (PRBA), with no requirement for stent implantation under most circumstances. However, an FMD recurrence after PRBA occurs frequently in these patients.

Accuracy of unenhanced magnetic resonance angiography for the assessment of renal artery stenosis

Purpose

To evaluate the accuracy of unenhanced magnetic resonance angiography (U-MRA) using balanced steady-state free precession (SSFP) sequences with inversion recovery (IR) pulses for the evaluation of renal artery stenosis.

Materials and methods

U-MRA was performed in 24 patients with suspected main renal artery stenosis. Two radiologists evaluated the quality of the imaging studies and the ability of U-MRA to identify hemodynamically significant main renal artery stenosis (RAS) defined as a stenosis ≥50% when compared to gold standard tests: contrast-enhanced magnetic resonance angiography (CE-MRA) (18 patients) or digital subtraction arteriography (DSA) (6 patients).

Results

A total of 44 main renal arteries were evaluated. Of them, 32 renal arteries could be assessed with U-MRA. When CE-MRA or DSA was used as the reference standard, nine renal arteries had hemodynamically significant RAS. U-MRA correctly identified eight out of nine arteries as having ≥50% RAS, and correctly identified 22 out of 23 arteries as not having significant RAS, with a sensitivity of 88.8%, a specificity of 95.65%, positive and negative predictive value of 88.8% and 95.65%, respectively, and an accuracy of 93.75%. Renal artery fibromuscular dysplasia (FMD) was observed in the two misclassified arteries.

Conclusion

U-MRA is a reliable diagnostic method to depict normal and stenotic main renal arteries. U-MRA can be used as an alternative to contrast-enhanced magnetic resonance angiography or computer tomography angiography in patients with renal insufficiency unless FMD is suspected.

To Stent or Not to Stent? Update on Revascularization for Atherosclerotic Renovascular Disease

Renal artery stenosis (RAS) is increasingly encountered in clinical practice. The two most common etiologies are fibromuscular dysplasia (FMD) and atherosclerotic renal artery disease (ARAS), with the latter accounting for the vast majority of cases. Significant RAS activates the renin-angiotensin-aldosterone system and is associated with three major clinical syndromes: ischemic nephropathy, hypertension, and destabilizing cardiac syndromes. Over the past two decades, advancements in diagnostic and interventional techniques have led to improved detection and the widespread use of endovascular renal artery revascularization strategies in the management of ARAS. However, renal artery stenting for ARAS remains controversial. Although several studies have demonstrated some benefit with renal artery revascularization, this has not been to the extent anticipated or predicted. Moreover, these trials have significant flaws in their study design and are hampered with inherent bias which make their interpretation challenging. In this review, we evaluate the existing body of evidence and offer an approach to the management of patients with ARAS in light of the current literature. From the data provided, identification of subgroup of patients, namely, those with a hemodynamically significant RAS in the context of progressive renal insufficiency and/or deteriorating arterial hypertension, seems possible and may derive clinical benefit from ARAS stent revascularization. Appropriate patient selection is therefore the key and more robust studies are required.