Risk of atrophy in kidneys with atherosclerotic renal artery stenosis

Associations of MRI-derived kidney volume, kidney function, body composition and physical performance in ≈38 000 UK Biobank participants: a population-based observational study

Background

Kidney volume is used as a predictive and therapeutic marker for several clinical conditions. However, there is a lack of large-scale studies examining the relationship between kidney volume and various clinicodemographic factors, including kidney function, body composition and physical performance.

Methods

In this observational study, MRI-derived kidney volume measurements from 38 526 UK Biobank participants were analysed. Major kidney volume-related measures included body surface area (BSA)-adjusted total kidney volume (TKV) and the difference in bilateral kidneys. Multivariable-adjusted linear regression and cubic spline analyses were used to explore the association between kidney volume-related measures and clinicodemographic factors. Cox or logistic regression was used to identify the risks of death, non-kidney cancer, myocardial infarction, ischaemic stroke and chronic kidney disease (CKD).

Results

The median of BSA-adjusted TKV and the difference in kidney volume were 141.9 ml/m2 [interquartile range (IQR) 128.1-156.9] and 1.08-fold (IQR 1.04-1.15), respectively. Higher BSA-adjusted TKV was significantly associated with higher estimated glomerular filtration rate {eGFR; β = 0.43 [95% confidence interval (CI) 0.42-0.44]; P < .001}, greater muscle volume [β = 0.50 (95% CI 0.48-0.51); P < .001] and greater mean handgrip strength [β = 0.15 (95% CI 0.13-0.16); P < .001] but lower visceral adipose tissue volume [VAT; β = -0.09 (95% CI -0.11 to -0.07); P < .001] in adjusted models. A greater difference in bilateral kidney volumes was associated with lower eGFR, muscle volume and physical performance but with higher proteinuria and VAT. Higher BSA-adjusted TKV was significantly associated with a reduced risk of CKD [odds ratio (OR) 0.7 (95% CI 0.63-0.77); P < .001], while a greater difference in kidney volume was significantly associated with an increased risk of CKD [OR 1.13 (95% CI 1.07-1.20); P < .001].

Conclusion

Higher BSA-adjusted TKV and lower differences in bilateral kidney volumes are associated with higher kidney function, muscle volume and physical performance and a reduced risk of CKD.

An Evaluation of Renal Sinus Fat Accumulation Using the Anteroposterior Diameter of the Renal Sinus on a Computed Tomography Axial Image

Backgrounds and objectives Renal sinus fat (RSF) is an indicator of obesity-related complications. However, the measurement and imaging process are complicated. For a simple measurement of RSF, we focused on the kidney's shape change caused by RSF accumulation. Thus, this study aimed to investigate whether the anteroposterior diameter of the renal sinus (APDRS) on a computed tomography (CT) axial image is useful for evaluating RSF accumulation. Materials and methods The correlation between APDRS and RSF was investigated in 98 outpatients who underwent abdominal CT. In addition, the correlation between APDRS or RSF and obesity indicators (estimated glomerular filtration rate from serum creatinine levels (eGFRcreat), body mass index (BMI), and visceral adipose tissue (VAT)) was also investigated. We classified patients based on the presence or absence of at least one underlying disease (chronic kidney disease (CKD), cardiovascular diseases (CVD), hypertension, and type 2 diabetes (T2D)) and investigated significant differences between the two groups at APDRS and RSF. The intraclass correlation coefficient (ICC) was also calculated for APDRS. Results There was a strong positive correlation between RSF and APDRS (r = 0.802, P < 0.01). The obesity indicators (eGFRcreat, BMI, and VAT) were correlated with RSF and APDRS (P < 0.01). Out of 98 outpatients, 48 had at least one underlying disease. There were statistically significant differences in APDRS and RSF between the patients with and without at least one of the underlying diseases caused by obesity (P < 0.01). The inter-reader ICC for the measurement of the APDRS was 0.98. Conclusions APDRS on a CT axial image may be useful for the evaluation of RSF accumulation.

Kidney Intrinsic Mechanisms as Novel Targets in Renovascular Hypertension

Almost a hundred years have passed since obstruction of the renal artery has been recognized to raise blood pressure. By now chronic renovascular disease (RVD) due to renal artery stenosis is recognized as a major source of renovascular hypertension and renal disease. In some patients, RVD unaccompanied by noteworthy renal dysfunction or blood pressure elevation may be incidentally identified during peripheral angiography. Nevertheless, in others, RVD might present as a progressive disease associated with diffuse atherosclerosis, leading to loss of renal function, renovascular hypertension, hemodynamic compromise, and a magnified risk for cardiovascular morbidity and mortality. Atherosclerotic RVD leads to renal atrophy, inflammation, and hypoxia but represents a potentially treatable cause of chronic renal failure because until severe fibrosis sets in the ischemic kidney, it retains a robust potential for vascular and tubular regeneration. This remarkable recovery capacity of the kidney begs for early diagnosis and treatment. However, accumulating evidence from both animal studies and randomized clinical trials has convincingly established the inadequate efficacy of renal artery revascularization to fully restore renal function or blood pressure control and has illuminated the potential of therapies targeted to the ischemic renal parenchyma to instigate renal regeneration. Some of the injurious mechanisms identified as potential therapeutic targets included oxidative stress, microvascular disease, inflammation, mitochondrial injury, and cellular senescence. This review recapitulates the intrinsic mechanisms that orchestrate renal damage and recovery in RVD and can be harnessed to introduce remedial opportunities.

Bilateral renal artery stenosis impacts postoperative complications after major vascular surgery

Background

Incidental atherosclerotic renal artery stenosis (RAS) is common in patients undergoing vascular surgery and has been shown to be associated with postoperative AKI among patients undergoing major non-vascular surgeries. We hypothesized that patients with RAS undergoing major vascular procedures would have a higher incidence of AKI and postoperative complications than those without RAS.

Methods

A single-center retrospective cohort study of 200 patients who underwent elective open aortic or visceral bypass surgery (100 with postoperative AKI; 100 without AKI) were identified. RAS was then evaluated by review of pre-surgery CTAs with readers blinded to AKI status. RAS was defined as ≥50 % stenosis. Univariate and multivariable logistic regression was used to assess association of unilateral and bilateral RAS with postoperative outcomes.

Results

17.4 % (n = 28) of patients had unilateral RAS while 6.2 % (n = 10) of patients had bilateral RAS. Patients with bilateral RAS had similar preadmission creatinine and GFR as compared to unilateral RAS or no RAS. 100 % (n = 10) of patients with bilateral RAS had postoperative AKI compared with 45 % (n = 68) of patients with unilateral or no RAS (p < 0.05). In adjusted logistic regression models, bilateral RAS predicted severe AKI (OR 5.82; CI 1.33, 25.53; p = 0.02), in-hospital mortality (OR 5.71; CI 1.03, 31.53; p = 0.05), 30-day mortality (OR 10.56; CI 2.03, 54.05; p = 0.005) and 90-day mortality (OR 6.88; CI 1.40, 33.87; p = 0.02).

Conclusions

Bilateral RAS is associated with increased incidence of AKI as well as in-hospital, 30-day, and 90-day mortality suggesting it is a marker of poor outcomes and should be considered in preoperative risk stratification.

Changes in Kidney and Liver Volumes in Patients With Autosomal Dominant Polycystic Kidney Disease Before and After Dialysis Initiation

Objective

To examine the changes in total kidney volume (TKV) and total liver volume (TLV) before and after dialysis initiation in patients with autosomal dominant polycystic kidney disease.

Patients and Methods

This was a retrospective, single-center cohort study to investigate the changes in TKV and TLV before and after dialysis initiation, along with influencing factors, using linear mixed models. We enrolled 95 patients with autosomal dominant polycystic kidney disease (85 receiving hemodialysis [HD] and 10 receiving peritoneal dialysis [PD]) who began receiving dialysis at Toranomon Hospital from January 1, 2008, to December 31, 2020.

Results

The least squares mean TKV ratio (TKV at each time point/TKV at dialysis initiation) was 63.8% (95% confidence interval [CI], 54.7%-72.9%) at 6 years before dialysis initiation and 95.5% (95% CI, 82.9%-108.2%) at 6 years after dialysis initiation (P<.001). A multivariate linear mixed model analysis revealed that dialysis style (HD or PD) had the strongest effect on changes in TKV (P=.002). The least squares mean TLV ratio was 98.2% (95% CI, 88.4%-108.0%) at 6 years before dialysis initiation and 95.7% (95% CI, 85.2%-106.2%) at 6 years after dialysis initiation (P=.01). Although PD did not have significant effects on changes in TLV (P=.27), the changes in TLV were greater in patients on PD than in those on HD.

Conclusion

The TKV increased until dialysis initiation and generally decreased after dialysis initiation. The TLV continued to increase even after dialysis initiation, however, changes in the TLV significantly decreased after dialysis initiation. The increases in TKV and TLV were greater in patients on PD than in those on HD.

A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis

BACKGROUND

Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters.

METHODS

The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis.

RESULTS

The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%.

CONCLUSION

Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

Revascularization for Renovascular Disease: A Scientific Statement From the American Heart Association

Renovascular disease is a major causal factor for secondary hypertension and renal ischemic disease. However, several prospective, randomized trials for atherosclerotic disease failed to demonstrate that renal revascularization is more effective than medical therapy for most patients. These results have greatly reduced the generalized diagnostic workup and use of renal revascularization. Most guidelines and review articles emphasize the limited average improvement and fail to identify those clinical populations that do benefit from revascularization. On the basis of the clinical experience of hypertension centers, specialists have continued selective revascularization, albeit without a summary statement by a major, multidisciplinary, national organization that identifies specific populations that may benefit. In this scientific statement for health care professionals and the public-at-large, we review the strengths and weaknesses of randomized trials in revascularization and highlight (1) when referral for consideration of diagnostic workup and therapy may be warranted, (2) the evidence/rationale for these selective scenarios, (3) interventional and surgical techniques for effective revascularization, and (4) areas of research with unmet need.

Gray-Scale, Color Doppler, Spectral Doppler, and Contrast-Enhanced Renal Artery Ultrasound: Imaging Techniques and Features

Renal artery stenosis (RAS) is increasingly being detected in elderly patients as life expectancy increases. RAS induces hypertension or reduces renal function. Computed tomography or magnetic resonance angiography are objective in detecting RAS but may cause iodine-induced nephrotoxicity or nephrogenic systemic fibrosis in patients with RAS. Ultrasound (US) is, by contrast, a noninvasive and real-time imaging modality useful in patients with reduced renal function. Renal US is not as sensitive for detecting RAS because this technique indirectly assesses the renal artery by analyzing intrarenal hemodynamic changes. Although, ideally, US would be used to directly evaluate the renal artery, its current utility for RAS detection remains unclear. The purpose of this review is to introduce how to assess renal artery with US, to describe imaging features of renal artery US, to compare renal artery US and renal US, and to show how to perform work-up in patients in whom RAS is suspected.

Autosomal Dominant Polycystic Kidney Disease in which the Polycystic Liver Volume Was Reduced by Rigorous Blood Pressure Control

Polycystic liver disease (PLD) is the most common extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). However, current treatments for PLD are only supportive. We experienced a case of enlarged kidneys and liver in a 53-year-old Japanese man with ADPKD who was on hemodialysis. He underwent renal transcatheter arterial embolization (TAE) for enlarged kidneys. His blood pressure (BP) decreased after renal TAE, and his liver volume decreased from 5,259 mL to 4,647 mL (11.6% reduction) within 1 year after renal TAE. This case suggests that rigorous blood pressure control may be beneficial for ameliorating enlarged PLD.

Atherosclerotic Renal Artery Stenosis: A Review

Renal artery stenosis (RAS) is associated with hypertension and renal impairment. Atherosclerosis is the leading etiologic factor which accounts for >90% of the cases. Those with atherosclerotic RAS (ARAS) tend to have concomitant atherosclerosis in other vascular beds, so they are at a high risk of adverse coronary and cerebrovascular events. Management of ARAS is controversial, with limited indications for revascularization. In this review, the author aims to discuss the pathophysiology, natural history, diagnosis, and management of ARAS.

Renovascular Hypertension in Chronic Hemodialytic Patient

Background: Hypertension is a major contributor to the development of chronic kidney disease. Data in Indonesia, hypertension is still the most comorbid disease in CKD patients on dialysis (51%). Hypertension in CKD on dialysis patients is common and often uncontrolled.  Renovascular hypertension is the most common cause of secondary hypertension. Diagnosis and treatment of RAS is very important, because it can accelerate the achievement of blood pressure targets, reduce the risk and complications due to hypertension. Case Report: A 52-year-old woman with CKD has been undergoing hemodialysis for 2 years. Hypertension that was previously well controlled for 2 years required an increase in antihypertensive therapy from 2 to 4 drugs in recent months. On physical examination the blood pressure 180/90 mmHg, pulse 79 bpm, respiration 20/min, temperature 36.7oC. Conjunctiva looks anemic, cardiomegaly, lungs within normal limits, no ascites and edema in the extremities. On renal artery duplex ultrasound examination, right main renal artery acceleration time 147.65 ms, Peak Systolic Velocity (PSV) 31.9 cm/s. RI 0.69 and left main renal artery acceleration time 120.81 ms, PSV 16.9 cm/s, RI 0.61. There was 20-30% left renal artery stenosis, 80% right renal artery stenosis. A stent was placed on the right renal artery. The patient's condition after PTRA improved, but at the next follow-up, mean systole and diastole 170 mmHg and 80 mmHg, respectively. Patient received 4 antihypertensive therapy. Conclusion: Renal artery stenosis is a disease that consists of a broad spectrum of different entities with different pathophysiologies that require varied approaches to diagnose and treat. Current diagnostic tools include MRA, CTA and renal artery duplex ultrasonography. Patients with renal parenchymal disease are poorer candidates for revascularization.

Pressure gradient measurement to verify hemodynamic results of the chimney endovascular aortic repair (chEVAR) technique

PURPOSE

The use of the pressure gradient measurements to assess the renal artery flow hemodynamics after chimney endovascular aortic repair (chEVAR).

METHODS

The study was a prospective analysis of 37 chEVAR procedures performend in 24 patients with perirenal aortic aneurysm. In all patients the measurement of: distal renal artery pressure (Pd), aortic pressure (Pa), Pd/Pa ratio (Pd/Pa) and mean gradient (MG) between the aorta and the distal renal artery were performed. Measurements were taken with 0.014 inch pressure wire catheter before and after the chEVAR procedure. MG greater than 9 mmHg and Pd/Pa ratio below 0.90 were considered as the measures of a significant decrease in distal pressure that limited flow in renal arteries. The 6 month follow-up computed tomographic angiography (CTA) was performed in all patients to diagnose potential endoleak presence and to verify the patency of the chimney stent-grafts.

RESULTS

All procedures were successful, and no periprocedural complications were observed in any of the patients. The mean gradient values before and after the chimney implantation did not change significantly (6,2±2,0 mmHg and 6,8±2,2 mmHg, respectively). Similarly, no significant change in Pd/Pa values was noted with the value of 0.9 observed both before and after the procedure. All chimney stents were patent on the control CTA. Type Ia endoleak was found in 4 (10.8%) patients.

CONCLUSIONS

The application of the described technique seems to be a safe method which allows a direct measurement of renal artery flow hemodynamics before and after chimney implantation during the chEVAR technique. The use of covered balloon expandable stents, ensures the proper blood flow in the renal arteries during the chEVAR technique.

Renal artery stenosis

Renal artery stenosis is the most common secondary cause of hypertension and predominantly caused by atherosclerosis. In suspected patients, a non-invasive diagnosis with ultrasound is preferred. Asymptomatic, incidentally found RAS does not require revascularization. In symptomatic patients requiring revascularization, renal artery stenting is the preferred therapy. Selecting appropriate patients for revascularization requires careful consideration of lesion severity and is optimized with a multidisciplinary team. All patients with atherosclerotic RAS should be treated with guideline-directed medical therapy, including hypertension control, diabetes control, statins, antiplatelet therapy, smoking cessation and encouraging activity.

Renovascular Hypertension

Renovascular hypertension (RVH) is relatively common but underrecognized cause of resistant hypertension in clinical practice. Most patients with RVH have suboptimal control of hypertension in spite of being on multiple anti hypertensive medications. Prompt diagnosis and management is crucial to prevent long term morbidity and mortality. Initial evaluation by primary care physicians can expedite this to improve patient outcomes by co-managing hypertension specialists. In addition to pharmacologic and nonpharmacologic measures, some patients may benefit from angioplasty. This article discusses various definitions of hypertension, approach to diagnosis of RVH, and management. Data from clinical trials are discussed with evidence-based medicine practice recommendations.

Renal Artery Stenosis in the Patient with Hypertension: Prevalence, Impact and Management

Atherosclerosis is the primary cause of renal artery stenosis. Atherosclerotic renal artery stenosis (ARAS) is associated with three clinical problems: renovascular hypertension, ischemic nephropathy and cardiac destabilization syndrome which pose huge healthcare implications. There is a significant rate of natural disease progression with worsening severity of renal artery stenosis when renal revascularization is not pursued in a timely manner. Selective sub-groups of individuals with ARAS have had good outcomes after percutaneous renal artery stenting (PTRAS). For example, individuals that underwent PTRAS and had improved renal function were reported to have a 45% survival advantage compared to those without improvement in their renal function. Advances in the imaging tools have allowed for better anatomic and physiologic measurements of ARAS. Measuring translesional hemodynamic gradients has allowed for accurate assessment of ARAS severity. Renal revascularization with PTRAS provides a survival advantage in individuals with significant hemodynamic renal artery stenosis lesions. It is important that we screen, diagnosis, intervene with invasive and medical treatments appropriately in these high-risk patients.

How reliable is renal ultrasound to measure renal length and volume in patients with chronic kidney disease compared with magnetic resonance imaging?

Background

Renal length, volume, and parenchymal thickness are important clinical parameters, yet data concerning the accuracy and reproducibility of ultrasound (US)-based renal length and volume assessment in patients with chronic kidney disease (CKD) are scarce.

Purpose

To establish whether renal length, volume, and parenchymal thickness can be reliably measured with renal US in patients with CKD.

Material and Methods

All participants underwent renal US, immediately followed by 3-T magnetic resonance imaging (MRI). Renal length, width, transverse diameter, and parenchyma thickness were measured with both methods; renal volume was calculated using the ellipsoid formula. A total of 45 patients with CKD (eGFR [mean ± SD] 57.4 ± 4.4 mL/min/1.73 m2) and 46 participants without CKD (eGFR 97.0 ± 2.4 mL/min/1.73 m2) were included.

Results

US-measured renal length correlated strongly with MRI-measured renal length in no-CKD patients (Spearman’s r = 0.83 and 0.85 for the right and left kidney, respectively; P < 0.005) and CKD patients (r = 0.89 and 0.92 for the right and left kidney, respectively; P < 0.005). There was a significant but weaker correlation between MRI- and US-measured right and left renal volume (r = 0.72, P < 0.005) in no-CKD (r = 0.74 and r = 0.72, respectively; for both: P < 0.005) and CKD patients (r = 0.83 and 0.85, P < 0.005). Weak to moderate correlations were found for parenchyma thickness for the right (CKD group: r = 0.29, no-CKD: r = 0.23; for both: P < 0.05) and left kidney (CKD: r = 0.52, no-CKD group: r = 0.37, P < 0.05). Both intra-observer (Pearson’s correlations of 0.82 for the right and 0.89 for the left kidney) and inter-observer (Lin’s correlation coefficient of 0.90 for the right and 0.82 for the left kidney) reproducibility of US-assessed renal length was high.

Conclusions

US-based assessment of renal length in CKD patients is comparable to MRI measures. Both intra- and inter-observer reproducibility of US-assessed renal length in CKD patients are high. Measurements of US renal volume and parenchymal thickness should, however, be interpreted with caution.

[Can the pre-dialysis period in stage IV chronic kidney disease be prolonged?]

Analysed herein are the results of treating a total of 29 patients presenting with stage IV chronic kidney disease (CKD) induced by ischaemic nephropathy. All patients had renal artery stenosis more than 80%, decreased glomerular filtration rate (GFR) below 30 ml/min/1.73m2 and were regarded by the nephrologists as potential candidates for programmed haemodialysis. After preparation aimed at preventing contrast-induced nephropathy all patients underwent stenting of the stenosed renal arteries. In the early postoperative period, 21 patients were found to have stabilization of the GFR with a tendency to increase. One woman developed acute renal failure requiring renal replacement therapy by means of haemodialysis. During the follow-up period from 1 to 5 years, 26 patients showed no progression of azotemia. CKD changed to stage III in 15 patients (p<0.005). Twenty-three (84%) patients during the follow-up period developed no new cardiovascular events. Hence, performing renal revascularization for renal artery stenosis >80% revealed in patients with stage IV CKD promotes prolongation of the dialysis-free period.

Familial Hypercholesterolemia With Coexisting Renovascular Stenosis and Premature Coronary Artery Disease

Familial hypercholesterolemia (FH) is a common hereditary lipid disorder associated with substantial risk of premature atherosclerotic cardiovascular disease. We report an interesting newly diagnosed index case of FH in a 31-year-old man who presented to the hospital with an ST-elevated myocardial infarction. He had a background of inadequately treated hypertension and hypercholesterolemia. Further investigations raised the possibility of secondary hypertension after the identification of renal artery stenosis, in addition to other areas of mesenteric arterial stenoses. Our patient's case highlights that early-onset hypertension and hypercholesterolemia in a young individual may be an early manifestation of FH requiring high clinical vigilance and awareness.

Recanalization and stenting of total occlusions of the renal arteries for blood pressure control in resistant to treatment hypertension

OBJECTIVE

To evaluate whether percutaneous recanalization and stenting of totally occluded renal arteries is feasible and might be justified as effective in reducing the blood pressure (BP) in some patients with preserved collateral renal flow.

PATIENTS AND METHODS

Seven consecutive patients (3 women, 4 men) at average age of 42.8 years (range, 15-67 years) with resistant hypertension, high renin activity, renal artery occlusion and preserved subsegmental flow were included.

RESULTS

Endovascular recanalization was successful in 6 of 7 attempted cases. One month after the procedure the 24-h ABPM in the successfully recanalized renal CTO patients showed impressive decrease in the BP average of 138.5/81.7 mm Hg compared to 167.1/95.1 mm Hg before the procedure. Significant decrease in the drug medication was achieved. During the 6-month follow-up, two of the patients had in-stent restenosis- both successfully treated with endovascular reintervention. Secondary patency was 100% for 18 months thereafter and the BP control was excellent without medication increase.

CONCLUSIONS

The recanalization of total renal artery occlusions resulted feasible and safe in the described group of patients with resistant hypertension and high plasma rennin activity. The renal artery recanalization had a positive effect on lowering the plasma renin activity and BP control.

Atherosclerotic Renal Artery Stenosis: Should we Intervene Earlier?

Purpose of Review

Randomized trials have failed to show clinical benefit in patients with atherosclerotic renal artery stenosis who were treated with angioplasty with or without stenting. However, these studies were done in patients with a high-grade stenosis. This paper examines whether there are arguments to consider patients with low-grade stenosis for angioplasty.

Recent Findings

Patients with low-grade (< 50%) atherosclerotic renal artery stenosis have an excess risk for cardiovascular and renal complications. This could be related to inflammatory factors being generated by the stenotic kidney. Moreover, even a kidney with low-grade stenosis clears less or produces more of the natural nitric oxide inhibitor ADMA.

Summary

Patients with low-grade atherosclerotic renal artery stenosis have an increased risk for a variety of complications. In addition, the abnormality is progressive. There is a case for setting up a prospective trial to examine whether angioplasty confers benefit in patients with low-grade renal artery stenosis.

Current Concepts in the Treatment of Renovascular Hypertension

Renovascular disease (RVD) remains a major cause of secondary and treatment-resistant hypertension. Most cases are related either to fibromuscular or atherosclerotic lesions, but a variety of other causes including arterial dissection, stent occlusion, and embolic disease can produce the same syndrome. Recent studies emphasize the kidney's tolerance to moderate flow reduction during antihypertensive drug therapy and the relative safety of medical therapy to control blood pressure. Several prospective trials in moderate RVD fail to identify major benefits from endovascular revascularization for moderate atherosclerotic disease. However, high-risk and progressive renovascular syndromes are recognized to be relatively refractory to medical therapy only and respond better to combining renal revascularization with ongoing medical therapy. Clinicians caring for complex hypertension should be familiar with pathogenic pathways, imaging techniques, and a rational approach to managing renovascular hypertension in the current era.

Food strategies of renal atrophy based on Avicenna and conventional medicine

Kidneys have an important role in the body. Any damage to kidney role can damage many organs of the body. Traditional Persian Medicine (TPM) or Iranian traditional medicine (ITM) is an ancient temperamental medicine with many literatures about kidney diseases and Avicenna (980-1025 AD) describes kidney diseases in details. This is a review study by searching of the most important clinical and pharmaceutical TPM textbooks such as The Canon of Medicine by Avicenna and scientific data banks using keywords such as "Hozal-e-Kolye", renal atrophy, tubular atrophy, kidney, chronic kidney disease, and end stage renal disease. This paper found that "Hozal-e-Kolye" in TPM texts is the same tubular atrophy in conventional medicine due to some similar symptoms between them. Lifestyle modification and use of proposed foodstuffs can be considered as a complementary medicine in addition to conventional treatments to manage these patients. TPM scholars prescribed some foodstuffs such as camel milk, sheep's milk and Ficus carica for this disease as a complementary management. This study aimed to explain HK (the same tubular atrophy considering their similar symptoms) and introduce some foodstuffs. It seems using of foodstuffs affecting tubular atrophy based on TPM literatures can has a role as a supplemental method in company with conventional medicine management.

Relation between Kidney Length and Cardiovascular and Renal Risk in High-Risk Patients

BACKGROUND AND OBJECTIVES

Kidney length is often measured during routine abdominal ultrasonography and may be of use to identify patients at high vascular and renal risk. We aimed to explore patient characteristics related to kidney length, from which reference values were derived, and evaluate the relationship between kidney length and the risk of cardiovascular events and ESRD in high-risk patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The study population consisted of 10,251 patients with clinical manifest arterial disease or vascular risk factors included in the Second Manifestations of ARTerial disease (SMART) Study cohort between 1996 and 2014. Linear regression was used to explore patient characteristics of kidney length. The relationship between kidney length and cardiovascular events (myocardial infarction, stroke, and cardiovascular mortality), all-cause mortality, and ESRD was analyzed using Cox regression. Kidney length was analyzed in tertiles, using the second tertile as the reference category.

RESULTS

Kidney length was strongly correlated with body surface area (2.04 mm; 95% confidence interval [95% CI], 1.95 to 2.13 per 0.1 m2 increase) and eGFR (1.62 mm; 95% CI, 1.52 to 1.73 per 10 ml/min per 1.73 m2 increase). During the median follow-up of 6.3 years, 1317 patients experienced a cardiovascular event, including 711 myocardial infarctions, 369 strokes, and 735 vascular cause deaths. A total of 1462 patients died of any cause and 52 patients developed ESRD. Irrespective of eGFR, patients in the third tertile of kidney length (11.7-16.1 cm) were at higher risk of cardiovascular mortality (hazard ratio, 1.33; 95% CI, 1.05 to 1.67) and cardiovascular events (hazard ratio, 1.28; 95% CI, 1.09 to 1.50). Patients in the first tertile of kidney length (7.8-10.8 cm) were not at higher risk of cardiovascular adverse events.

CONCLUSIONS

Large kidney length is related to higher risk of cardiovascular events and mortality in high-risk patients, irrespective of eGFR. Kidney length may serve as a clinical marker to further identify patients at high cardiovascular risk.

Resultados a longo prazo da angioplastia de artérias renais com stent na doença aterosclerótica: revisão sistemática

Resumo A doença renovascular aterosclerótica é a principal causa de hipertensão secundária. A história natural da doença demonstra taxas de progressão de 4 a 12% ao ano. Entre os métodos de tratamento existe a angioplastia com stent de artérias renais; porém, poucos estudos clínicos demonstraram seus resultados a longo prazo. Esta revisão sistemática da literatura se propõe a apresentar os resultados a longo prazo (acima de 24 meses) da angioplastia com stent de artérias renais na doença aterosclerótica em relação à função renal e aos níveis pressóricos no controle da hipertensão. Foi realizada uma ampla pesquisa, utilizando os termos apropriados, nas bases de dados LILACS, EMBASE, SCIELO, Cochrane Library e MEDLINE. De um total de 2.170 referências, apenas sete artigos contemplavam todos os critérios de inclusão. Conclui-se que, a longo prazo, há uma estabilização da função renal, redução dos níveis pressóricos e diminuição do número de classes de medicamentos anti-hipertensivos.

Endovascular Management of Atherosclerotic Renal Artery Stenosis: Post-Cardiovascular Outcomes in Renal Atherosclerotic Lesions Era Winner or False Alarm?

Renal artery stenosis (RAS) is frequently associated with severe comorbidities such as reduced renal perfusion, hypertension, and end-stage renal failure. In approximately 90% of patients, renal artery atherosclerosis is the main cause for RAS, and it is associated with an increased risk for fatal and non-fatal cardiovascular and renal complications. Endovascular management of atherosclerotic RAS (ARAS) has been recently evaluated by several randomized controlled trials that failed to demonstrate benefit of stenting. Furthermore, the Cardiovascular Outcomes in Renal Atherosclerotic Lesions study did not demonstrate any benefit over the revascularization approach. In this review, we summarized the available data from retrospective, prospective and randomized trials on ARAS to provide clinicians with sufficient data in order to produce useful conclusions for everyday clinical practice.

Revascularization in a 17-Year-Old Girl with Neurofibromatosis and Severe Hypertension Caused by Renal Artery Stenosis

Renal artery stenosis caused by neurofibromatosis is a rare cause of renovascular hypertension. This hypertension can develop during childhood and is one of the leading causes of poor outcome. We report the case of a 17-year-old girl who was incidentally diagnosed with severe hypertension. During her examination for secondary hypertension, we reached a diagnosis of neurofibromatosis type 1 on the basis of a cluster of typical findings: optic nerve glioma, café au lait spots, nodular neurofibromas, and axillary freckling. Renal angiograms revealed a hemodynamically significant left renal artery stenosis (70%). Renal angioplasty with a self-expanding stent was performed one month later for rapidly progressive renal artery stenosis (90%) and uncontrolled blood pressure. Excellent blood pressure control resulted immediately and was maintained as of the 2-year follow-up evaluation. We think that percutaneous transluminal renal angioplasty can be effective in select patients who have neurofibromatosis type 1 and refractory hypertension caused by renal artery stenosis.

Percutaneous Endovascular Therapy of Renal Artery Stenosis: Technical and Clinical Developments in the past Decade

Renal artery stenosis may initiate or exacerbate arterial hypertension and/or renal insufficiency. During the last decade, technical improvements of diagnostic and interventional endovascular tools have led to more widespread use of endoluminal renal artery revascularization and broader indications for this type of therapy. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig in 1978, numerous single-center studies have documented the benefits of percutaneous renal revascularization. In the early 1990s, stent implantation was added to the interventionist's armamentarium for treating renal artery stenosis due to atherosclerosis or fibromuscular dysplasia. The metaanalysis of 3 randomized studies comparing balloon angioplasty with best medical therapy found intervention to be beneficial for blood pressure control but not for preservation of renal function. Despite the absence of randomized studies, there is mounting evidence that stenting of hemodynamically relevant atherosclerotic renal artery stenosis has a positive impact on blood pressure control and renal function. This article summarizes the technical improvements in these endovascular tools during the last decade and gives an overview concerning their clinical impact on renal artery revascularization.

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.

Left Renal Cortical Thickness Measured by Ultrasound Can Predict Early Progression of Chronic Kidney Disease

AIMS

The kidney becomes atrophic in advanced chronic kidney disease, and renal size and parenchymal volume correlate with renal function. However, alterations in renal parenchymal volume have not been adequately studied in terms of the renal cortex and medulla. We investigated the relationship between the changes in the renal cortex and medulla and renal function.

METHODS

Renal ultrasound (US) parameters including renal length, parenchymal thickness, cortical thickness and medullary thickness were assessed in 176 subjects, who were categorized into 4 groups based on the estimated glomerular filtration rate (ml/min/1.73 m2): group 1, ≥ 90; group 2, ≥ 60 but < 90; group 3, ≥ 30 but < 60; and group 4, < 30. Renal US parameters in both kidneys were compared among the 4 groups.

RESULTS

We found stepwise associations in renal length, cortical thickness and parenchymal thickness with decreased renal function. Medullary thickness showed no changes among groups 1-3. Multiple linear regression analysis including sex, age and renal US parameters showed that only renal length was an independent predictor of renal function. When analyzed in groups 1-3, cortical thickness was the strongest associated parameter. Lower cortical left/right ratio (left cortical thickness/right cortical thickness) showed a stepwise association with a decrease in renal function.

CONCLUSION

Renal length and cortical thickness measured by US were correlated with renal function. In particular, left cortical thickness could help to detect early changes in renal function.

From the 1990s to CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) trial results and beyond: does stenting have a role in ischemic nephropathy?

The prevalence of atherosclerotic renal artery stenosis is high, ∼7% in individuals older than 65 years and ∼50% in patients with diffuse arterial disease, and it is increasingly frequent in an aging population. About 10% to 15% of atherosclerotic renal artery stenosis cases lead to the development of resistant hypertension and/or ischemic nephropathy. The management of ischemic nephropathy may include medical therapy and/or revascularization. In the past, revascularization required surgical bypass or endarterectomy, accompanied by the morbidity and mortality associated with a major surgical procedure. During the last few decades, less invasive endovascular procedures such as percutaneous transluminal renal artery angioplasty with stent placement have become available. At the same time, new antihypertensive and cardiovascular drugs have been developed, which may preclude revascularization, at least in some cases. The indications of each of these therapeutic options have changed over time. This review offers a temporal perspective on the course of technical and scientific advances and the accompanying change in clinical practice for the treatment of ischemic nephropathy. The latest randomized clinical trials, including the CORAL (Cardiovascular Outcomes in Renal Atherosclerotic Lesions) trial, the largest on the subject, as well as a meta-analysis of these studies, have indicated that the best approach is medical therapy alone. There is evidence that revascularization brings no additional benefit, at least in low-risk and stable atherosclerotic renal artery stenosis. High-risk patients, especially those with recurrent flash pulmonary edema, could benefit from percutaneous transluminal renal artery angioplasty and stent placement, but there is no definitive evidence and the treatment choice should take into account the risks and potential benefits of the procedure.

[Ischemic renal disease and renal artery stenosis]

Severe renal artery stenosis may cause renovascular hypertension; in case of bilateral narrowing or in a stenotic solitary or transplant kidney, renal insufficiency (ischemic renal disease) or rarely pulmonary flash edema may occur. In most cases arteriosclerotic disease is the underlying cause; less prevalent are the various manifestations of fibromuscular disease. Renal artery stenosis may be treated by revasularization, using either percutaneous (balloon angioplasty, stenting) or rarely open surgical procedures, both with excellent primary patency rates. However, randomized trials of renal artery angioplasty or stenting in patients with arteriosclerotic lesions have failed to demonstrate a longer-term benefit with regard to hypertension control and renal dysfunction over medical management alone. Careful patient selection is essential to maximize the potential benefit (e.g., in patients with refractory hypertension, progressive renal failure or recurrent pulmonary flash edema).

Renal artery stenosis: epidemiology and treatment

Renal artery stenosis (RAS) is a frequently encountered problem in clinical practice. The disease encompasses a broad spectrum of pathophysiologies and is associated with three major clinical syndromes: ischemic nephropathy, hypertension, and destabilizing cardiac syndromes. The two most common etiologies are fibromuscular dysplasia and atherosclerotic renal artery disease with atherosclerotic disease accounting for the vast majority of cases. Atherosclerotic renovascular disease has considerable overlap with atherosclerotic disease elsewhere and is associated with a poor prognosis. A wide range of diagnostic modalities and treatment approaches for RAS are available to clinicians, and with the advent of endovascular interventions, selecting the best course for a given patient has only grown more challenging. Several clinical trials have demonstrated some benefit with revascularization but not to the extent that many had hoped for or expected. Furthermore, much of the existing data is only marginally useful given significant flaws in study design and inherent bias. There remains a need for further identification of subgroups and appropriate indications in hopes of maximizing outcomes and avoiding unnecessary procedures in patients who would not benefit from treatment. In recent decades, the study of RAS has expanded and evolved rapidly. In this review, we will attempt to summarize the amassed body of literature with a focus on the epidemiology of RAS including prevalence, overlap with other atherosclerotic disease, and prognosis. We will also outline existing diagnostic and treatment approaches available to clinicians as well as summarize the findings of several major clinical trials. Finally, we will offer our perspective on future directions in the field.

Genetic and environmental variance of renal parenchymal thickness: a twin study

AIM

To estimate heritability and environmental effects on renal parenchymal thickness.

METHODS

In this twin study, renal parenchymal thickness of 98 Hungarian healthy adult twin pairs (68 monozygotic, 30 dizygotic) without kidney disease was measured bilaterally using renal ultrasound with Esaote MyLab 70X ultrasound machine with low-frequency curved transducers (1-8 MHz).

RESULTS

In both monozygotic and dizygotic group there were more women (76.5%). Mean right and left renal parenchymal thickness was 1.32±0.33 cm and 1.62±0.31 cm, respectively. Age- and sex-adjusted heritability of renal parenchymal thickness was 0.0% (95% confidence interval, 0.0 to 50.2%), shared and unshared environmental factor was 30.2% (4.1 to 55.9%) and 69.8% (45.8 to 89.5%), respectively.

CONCLUSION

This study shows a negligible role of heritability and an important role of environmental effects in developing renal parenchymal thickness, emphasizing the importance of lifestyle for primary prevention.

Revascularization as a treatment to improve renal function

An aging atherosclerosis-prone population has led to an increase in the prevalence of atherosclerotic renovascular disease (ARVD). Medical management of this disease, as with other atherosclerotic conditions, has improved over the past decade. Despite the widespread availability of endovascular revascularization procedures, there is inconsistent evidence of benefit in ARVD and no clear consensus of opinion as to the best way to select suitable patients for revascularization. Several published randomized controlled trials have attempted to provide clearer evidence for best practice in ARVD, but they have done so with varying clarity and success. In this review, we provide an overview of ARVD and its effect on renal function. We present the currently available evidence for best practice in the management of patients with ARVD with a particular focus on revascularization as a treatment to improve renal function. We provide a brief overview of the evidence for revascularization in other causes of renal artery stenosis.

Non-coronary atherosclerosis

During the last decades, the clinical and research interest in atherosclerosis has been mostly focused on coronary arteries. After the publications of the European Society Guidelines and AHA/ACC Guidelines on Peripheral artery diseases, and of the Registry REduction in Atherothrombosis for Continued Health Registry, there has been an increased interest in atherosclerosis of the lower extremity arteries and its presence in multifocal disease. However, awareness in the general population and the medical community of non-coronary artery diseases, and of its major prognostic implications remain relatively low. The aim of this general review stemming out of an ESC Working Group on Peripheral Circulation meeting in 2011 is to enhance awareness of this complex disease highlighting the importance of the involvement of atherosclerosis at different levels with respect to clinical presentation, diagnosis, and co-existence of the disease in the distinct arterial territories. We also emphasize the need of an interdisciplinary approach to face the broad and complex spectrum of multifocal disease, and try to propose a series of tentative recommendations and measures to be implemented in non-coronary atherosclerosis.

Renal artery stenosis - an update

Renal artery stenosis (RAS) is a common form of peripheral arterial disease. The most common cause of RAS is atherosclerosis. It is predominantly unilateral. The pathophysiologic mechanism stems from renal underperfusion resulting in the activation of the renin- angiotensin-aldosterone pathway. Even though the majority of patients with RAS are asymptomatic, it can clinically present with hypertension, nephropathy and congestive heart failure. This progressive disease can lead to resistant hypertension and end stage kidney failure. Screening patients for RAS with either Doppler ultrasonography, computed tomographic angiography, or magnetic resonance angiography is preferred. Adequate blood pressure control, goal-directed lipid-lowering therapy, smoking cessation, and other preventive measures form the foundation of management of patients with RAS. Catheter-based percutaneous revascularization with angioplasty and stenting showed modest clinical benefit for patients in small retrospective studies, but data from randomized clinical trials failed to confirm these beneficial results. The current ongoing Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial may provide more concrete data regarding the role of stenting in RAS. Surgical revascularization is considered only if catheter-based revascularization is unsuitable or unsuccessful. The American College of Cardiology/American Heart Association guidelines on evaluation and management of patients with RAS provide the framework for determining individualized assessment and treatment plans for patients with RAS.

Results of the retrospective analysis of renal artery stenting for the salvage of renal function study

Renal artery stenting is expected to improve or stabilize renal function. However, the efficacy of renal artery stenting in severely reduced renal function is unclear. We evaluated 23 patients with class IV or V renal dysfunction who were treated for renal artery stenosis between 2004 and 2009. Improvement in renal function was found in 7 (30%) patients, all of whom were treated with distal protection device. Deterioration of renal function was found in 4 (17%) cases. In these 4 cases, distal protection device could not be used for anatomical reasons. The use of distal protection device was associated with significantly less renal deterioration after the procedure (P < .05, odds ratio 0.21 [confidence interval 0.09-0.50]). Renal artery stenting can stabilize or improve renal function in patients with severe renal dysfunction. Distal protection devices may be beneficial in patients who require renal artery stenting due to severely reduced renal function.

Prevalence and risk factors of CKD in Chinese patients with periodontal disease

BACKGROUND

Periodontal disease is common among adults and is associated with an increasing risk of chronic kidney disease (CKD). We aimed to investigate the prevalence and risk factors of CKD in patients with periodontal disease in China.

METHODS

In the current cross-sectional study, patients with periodontal disease were included from Guangdong Provincial Stomatological Hospital between March 2011 and August 2011. CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2), the presence of albuminuria, or hematuria. All patients with periodontal disease underwent a periodontal examination, including periodontal probing pocket depth, gingival recession, and clinical attachment level by Florida Probe. They completed a questionnaire and had blood and urine samples taken. The adjusted prevalence of indicators of kidney damage was calculated and risk factors associated with CKD were analyzed.

RESULTS

A total of 1392 patients with periodontal disease were invited to participate this study and 1268 completed the survey and examination. After adjusting for age and sex, the prevalence of reduced eGFR, albuminuria, and hematuria was 2.7% (95% CI 1.7-3.7), 6.7% (95% CI 5.5-8.1) and 10.9% (95% CI 9.2-12.5), respectively. The adjusted prevalence of CKD was 18.2% (95% CI 16.2-20.3). Age, male, diabetes, hypertension, history of CKD, hyperuricemia, and interleukin-6 levels (≥7.54 ng/L) were independent risk factors for reduced eGFR. Female, diabetes, hypertension, history of CKD, hyperuricemia, high level of cholesterol, and high sensitivity C-reactive protein (hsCRP) (≥ 1.03 mg/L) and TNF-α levels (≥ 1.12 ng/L) were independently associated with an increased risk of albuminuria. Female, lower education (<high school), and history of CKD were independent risk factors for hematuria.

CONCLUSIONS

18.2% of Chinese patients with periodontal disease have proteinuria, hematuria, or reduced eGFR, indicating the presence of kidney damage. Whether prevention or treatment of periodontal disease can reduce the high prevalence of CKD, however, remains to be further investigated.

A decline in glomerular filtration rate rather than renal arterial stenotic lesions, per se, predicts cardiovascular-renal events in type 2 diabetic patients

BACKGROUND

In diabetic patients with renal artery arteriosclerosis (RAAS), the factors associated with a greater risk for cardiovascular-renal events (CVREs) remain unclear: the decline in estimated glomerular filtration rate (eGFR) caused by RAAS or the advance of arteriosclerosis that causes RAAS. Hence, the features to determine which best predicts the onset of CVREs in such patients were compared.

METHODS AND RESULTS

The renal arteries of 162 type 2 diabetes patients were assessed by using magnetic resonance angiography (RAAS diagnosed as arteriosclerotic stenosis ≥50%) and they were studied longitudinally over 7 years. The influence of the presence/absence of RAAS, a decline in eGFR, clinical factors, surrogate arteriosclerotic markers and ischemic markers on patient's CVREs were assessed. A Cox regression analysis showed the detection of RAAS to be an independent risk factor for CVREs (bilateral RAAS was an extremely strong risk factor for the development of CVREs within 1,000 days), as was the decline in eGFR in a logistic regression analysis; the latter being a more powerful risk factor for CVREs. A multiple regression analysis revealed angiopoietin-2, a marker of ischemia, to be a risk factor for the decline in eGFR.

CONCLUSIONS

A decline in renal function but not the renal arterial stenotic lesion itself appears to be associated with an increased incidence of CVREs in type 2 diabetic patients with RAAS.

The incidence of renal artery stenosis in the patients referred for coronary artery bypass grafting

Multivessel coronary disease or peripheral arterial disease is the clinical clue to diagnosis of renal artery stenosis (RAS). RAS is considered equivalent to coronary artery disease in terms of cardiovascular risk. In this study, we evaluated the incidence of RAS in the patients who were proposed to undergo coronary artery bypass grafting (CABG). Diagnostic evaluations of coronary arteriography and renal artery angiography were performed during the same procedure; the patients who were proposed for CABG in terms of CAD anatomy and clinical manifestation were enrolled. RAS was evaluated and a diameter stenosis of ≥50% was considered as significant RAS; significant RAS patients were divided into five groups. The five groups of RAS were as follows: (1) unilateral RAS ≥50–70%, (2) unilateral RAS ≥70%, (3) bilateral RAS ≥50–70%, (4) one-renal-artery stenosis ≥50–70%, contralateral RAS ≥70%, and (5) bilateral renal artery stenosis ≥70%. A total of 151 patients were enrolled, and RAS (≥50% stenosis in either or both renal arteries) was identified in 47.02% (71/151) patients. Unilateral RAS ≥50–70% was identified in 16.6% (25/151) patients, unilateral RAS ≥70% in 4.6% (7/151) patients, bilateral RAS ≥50–70% in 7.9% (12/151) patients, one-renal-artery stenosis ≥50–70% and contralateral RAS ≥70% in 7.9% (12/151) patients, and bilateral RAS ≥70% was in 9.9%(15/151) patients. The incidence of RAS was 29.03% (18/62) in patients aged ≤60 years, 60% (36/60) in patients aged >60 and ≤70 years, and 58.62% (17/29) in patients aged >70 years. The incidence of RAS was significantly higher in patients aged >60 - ≤70, and >70 years than patients aged ≤60 years (P = 0.001 and P = 0.007, respectively). There was a trend that the incidence of RAS in patients with hypertension [HTN, 50.40% (64/127)] was higher than those without HTN (29.17%, 7/24), with P = 0.056. The incidence of RAS was 47.02% in patients who were proposed for CABG; bilateral RAS of ≥70% was 9.9%. Older age and HTN were associated with RAS in patients who were referred for CABG. This study indicates that the incidence of RAS was high in the patients referred for CABG, and the renal function should be taken care of.

The prevalence of renal artery stenosis among patients with diabetes mellitus

BACKGROUND

Patients with diabetes mellitus (DM) have a high prevalence of atherosclerotic vascular lesions. It is therefore reasonable to assume that also the rate of renal artery stenosis (RAS) is higher. The presence of a RAS can have implications for the treatment of patients with diabetes mellitus and hypertension and renal impairment. Therefore it is important to be informed about the chance that a RAS is present among such patients.

METHODS

We prospectively studied the prevalence of atherosclerotic renal artery stenosis (RAS) among patients with diabetes mellitus. Patients were included if they were diagnosed with DM and hypertension with or without impairment of renal function. If causes of renal disease other than DM or hypertension were more probable on the basis of biochemical data, then such patients were excluded. A magnetic resonance angiography (MRA) of the renal arteries was made in 54 included successive patients.

PATIENT CHARACTERISTICS

mean age 59 ± 8.5 years (range 35 to 80). Eight patients had DM 1 and 46 DM 2. Mean BMI was 31.4 ± 5.6 kg/m(2). A RAS was present in 18 of the 54 (33%) patients, 3 patients had bilateral stenoses. Factors related to the presence of RAS were diastolic blood pressure, glomerular filtration rate and dyslipidaemia.

CONCLUSION

In this group of diabetic patients with hypertension and or renal impairment the prevalence of RAS was 33%.

[Effects of endovascular therapy for renal artery stenosis on blood pressure and renal function: retrospective analysis of an unselected patient collective from 1994 to 2007]

BACKGROUND

A retrospective analysis of the long-term success rates of endoluminal therapy of renal artery stenosis in a university hospital was carried out.

MATERIAL AND METHODS

Preinterventional and postinterventional data contained in the clinical records of all 104 patients who underwent percutaneous transluminal angioplasty (PTA, 25 patients) or stent PTA (79 patients) from 01 January 1994 to 31 December 2007, were documented using an electronically structured questionnaire and a time period classification. Subgroup analyses and statistical calculations were done using t-tests for joint random samples.

RESULTS

At day 1 postintervention all patients showed a statistically significant decrease in mean systolic blood pressure (all patients: p=0.002, stent PTA group: p=0.023, PTA group: p=0.022). The significant decrease in mean systolic blood pressure persisted in years 1 and 2 postintervention (all patients: p=0.009 and 0.007, stent PTA group: p=0.039 and 0.015, respectively). Mean blood pressure values remained constant during the other time periods analyzed. In patients with a stent PTA carried out between 2001 and 2007 there was no significant reduction of prescribed antihypertonic drugs (p=0.023 and p=0.046, respectively). Mean serum creatinine concentrations decreased during years 1 and 2 postintervention and increased starting in year 3. In patients with elevated serum creatinine levels prior to the intervention the increase in mean serum creatinine level started in year 5.

CONCLUSIONS

Endoluminal therapy of arteriosclerotic renal artery stenosis delays further deterioration of renal function and stabilizes blood pressure as well as the number of prescribed antihypertonic drugs. This can be considered a response to treatment in view of the mostly chronic progressive course of the disease.

Significant reduction in systolic blood pressure following renal artery stenting in patients with uncontrolled hypertension: results from the HERCULES trial

BACKGROUND

Atherosclerotic renal artery stenosis (ARAS) causes hypertension (HTN) and threatens renal function (RF). The HERCULES Trial is a prospective, multicenter trial of renal stenting in patients with uncontrolled HTN and ARAS evaluating the safety and effectiveness of the RX Herculink Elite Renal Stent System (Abbott Vascular, Santa Clara, CA).

METHODS

A total of 202 patients (241 total lesions; 78 bilateral lesions) were enrolled between August 2007 and October 2009. The primary endpoint was 9-month binary restenosis determined by duplex ultrasound and/or angiography. Secondary endpoints included changes in blood pressure, antihypertensive medications, and RF between baseline and 9 months. Brain natriuretic peptide (BNP) was measured at baseline, 24 hr and 30 days postprocedure.

RESULTS

Mean systolic blood pressure (SBP) at baseline was 162 mm Hg. Nearly 70% of patients were receiving three or more antihypertensive medications (mean 3.4 medications per patient). Baseline serum creatinine was 1.2 ± 0.4 and 61.5% of subjects had estimated glomerular filtration <60. The restenosis rate was 10.5% at 9 months. The study device, procedure, and clinical success rates were 96.0, 99.2, and 98.0%, respectively. Freedom from major adverse events was 94.8%. At 9 months, the mean SBP significantly decreased (mean 145, paired t test P < 0.0001) after stenting with no change in medications. There was no correlation between SBP reduction and baseline BNP or BNP reduction.

CONCLUSIONS

HERCULES demonstrates clinically and statistically significant SBP reduction in patients with uncontrolled HTN, low in-stent restenosis, and complication rates. This study highlights that when appropriate patients are selected for renal artery stenting, impressive reductions in blood pressure may be anticipated. Although the magnitude of absolute reduction in SBP was related to baseline SBP, elevated baseline BNP levels were not predictive of reduction in SBP. Further studies for predictors of clinical response following percutaneous renal revascularization are needed.