Is renal artery stenting the correct treatment of renal artery stenosis? The case for renal artery stenting for treatment of renal artery stenosis

Concentration of serum uric acid in patients with Renal Artery Stenosis and Hypertension prEdict Future nephropathy and death: C-RASHEF study

Since both serum uric acid (SUA) and renal artery stenosis (RAS) are associated with atherosclerotic events and renal events, it is interesting to investigate whether SUA could predict long-term outcome in patients with RAS. Patients were enrolled from inpatients from 2010 to 2014, must be ≥40-year-old. There were 3269 hypertensive patients enrolled, including 325 RAS patients. Endpoints included all-cause death and new or worsening nephropathy (NNP). In analysis for all-cause mortality, associations between SUA and risk of all-cause mortality were an arising curve in total population, a U-shape curve in non-RAS population, and an arising curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of all-cause mortality was still an arising curve in total population. In analysis for NNP, associations between SUA and risk of NNP were a declining curve in total population, not significant in non-RAS population, and a U-shape curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of NNP in total population was no longer significant. Not only association curve of SUA with mortality in non-RAS patients is different from association curve in RAS patients, but also association curve of SUA with NNP in non-RAS patients is different from association curve in RAS patients. The authors conclude that mechanisms of uric acid for mortality and NNP in RAS patients are different from non-RAS patients. In addition to renal vascular obstruction, uric acid is another significant factor for NNP and death in RAS patients.

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.

Renal Arteries Revisited: Anatomy, Pathologic Entities, and Implications for Endovascular Management

The renal arteries (RAs) are important vessels that usually arise from the abdominal aorta and supply the kidneys; thus, these arteries play a vital role in physiologic functions such as hemofiltration and blood pressure regulation. An understanding of the basis for embryologic development and the frequently variable anatomy of the RAs is necessary to fully appreciate the range of diseases and the implications for procedural planning. Hemorrhage from an RA is relatively common and is typically traumatic or spontaneous, with the latter form often seen in association with underlying tumors or arteriopathy. Accurate diagnostic evaluation of RA disease due to conditions such as atherosclerosis, fibromuscular dysplasia, vasculitis, aneurysm, arteriovenous shunt, embolic disease, and dissection is dependent on the use of multimodality imaging and is essential for selecting appropriate clinical management, with endovascular therapy having a key role in treatment. Surgical considerations include extra-anatomic renal bypass, which remains an important treatment option even in this era of endovascular therapy, and RA embolization as an adjunct to tumor surgery. A novel area of research interest is the potential role of RA denervation in the management of refractory hypertension. ^©RSNA, 2021.

Mood Disorders in Uncontrolled Hypertension Despite Multiple Anti-Hypertensive Medications: Searching for a Link

INTRODUCTION

Resistant hypertension is a clinical condition in which blood pressure (BP) control is not achieved under a pharmacological therapy including a diuretic and at least two additional antihypertensive drug classes.

AIM

To discuss an unusual presentation of uncontrolled hypertension despite multiple anti-hypertensive medications.

METHODS AND RESULTS

A 46-year-old woman presented with resistant hypertension (HT) and with a long history of polydipsia, polyuria, weight loss and psychiatric symptoms (sudden onset of personality disorder with free anxiety, negativism and asthenia) unsuccessfully treated with antidepressant drugs. Tests for secondary HT showed a marked increase of serum renin and aldosterone both in clinostatic (342 pg/ml and 907 pmol/l, respectively) and orthostatic posture (351 pg/ml and 2845 pmol/l, respectively), hypokalemia (2.9 mmol/l) and macroalbuminuria (431 mg/day). Diagnostic examinations also revealed a focal stenosis of approximately 70 % of the proximal right renal artery with post-stenotic dilation. After percutaneous balloon angioplasty and stent implantation, BP was normalized with 5 mg/day amlodipine and psychiatric symptoms suddenly disappeared.

CONCLUSIONS

Psychopathological symptoms are rare at the onset of hyperaldosteronism, and their aetiology is not well defined. A proper diagnostic and therapeutic process is mandatory in order to get the recommended therapeutic targets in short-midterm improving long-term prognosis. We also suggest not considering depressed or treat with antidepressant agents a young hypertensive subject with uncontrolled hypertension despite multiple anti-hypertensive medications without having ruled out a secondary form of hypertension.

Analysis of Renal Artery Stenosis in Patients with Heart Failure: A RASHEF Study

BACKGROUND

Previous data are controversial about the association of renal artery stenosis (RAS) with clinical outcome in patients with heart failure. Definition of RAS in previous studies might not be appropriate. By definition of RAS with renal duplex sonography, we investigated the association of RAS with clinical outcome in patients with heart failure.

METHODS

In this retrospective study, we identified 164 patients with heart failure (New York Heart Association classification ≥II; left ventricular ejection fraction <50%) who had received renal duplex sonography during hospital stay. RAS was defined as renal-aortic ratio ≥3.5 or a peak systolic velocity ≥200 cm/s (or both), or occlusion of the renal artery. Categorical data of patients were compared using the Chi-square test or Fisher's exact test. Cox proportional hazards regression modeling technique was used to investigate the prognostic significance of possible predictors.

RESULTS

Finally, 143 patients were enrolled. Median follow-up time was 32 months (1-53 months). Twenty-two patients were diagnosed as RAS by renal duplex sonography, including 13 unilateral RAS (3 left RAS, 10 right RAS) and 9 bilateral RAS. There were more all-cause mortality and cardiovascular death in patients with RAS than patients without RAS. By multivariate analysis, RAS was a significant predictor for all-cause death and cardiovascular death (hazard ratio [HR] = 4.155, 95% confidence interval [CI]: 1.546-11.164, P = 0.005; and HR = 3.483, 95% CI: 1.200-10.104, P = 0.022, respectively). As for composite endpoint events, including death, nonfatal myocardial infarction, ischemic stroke or intracranial hemorrhage, rehospitalization for cardiac failure, and renal replacement therapy, only angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker was significant predictor. RAS was not a significant predictor for composite endpoint events.

CONCLUSIONS

Our data suggested that RAS is associated with a poorer clinical outcome in patients with heart failure.

Angiogenic cytokines in renovascular disease: do they have potential for therapeutic use?

Experimental and clinical studies suggest that the damage of the renal microvascular function and architecture may participate in the early steps of renal injury in chronic renal disease, irrespective of the cause. This supporting evidence has provided the impetus to targeting the renal microvasculature as an attempt to interfere with the progressive nature of the disease process. Chronic renovascular disease is often associated with renal microvascular dysfunction, damage, loss, and defective renal angiogenesis associated with progressive renal dysfunction and damage. It is possible that damage of the renal microvasculature in renovascular disease constitutes an initiating event for renal injury and contributes towards progressive and later on irreversible renal injury. Recent studies have suggested that protection of the renal microcirculation can slow or halt the progression of renal injury in this disease. This brief review will focus on the therapeutic potential and feasibility of using angiogenic cytokines to protect the kidney microvasculature in chronic renovascular disease. There is limited but provocative evidence showing that stimulation of vascular proliferation and repair using vascular endothelial growth factor or hepatocyte growth factor can slow the progression of renal damage, stabilize renal function, and protect the renal parenchyma. Such interventions may potentially constitute a sole strategy to preserve renal function and/or a co-adjuvant tool to improve the success of current therapeutic approaches in renovascular disease.

Nefropatia isquêmica

A doença renal isquêmica ou nefropatia isquêmica relacionada à doença renovascular pode evoluir de forma rápida e progressiva para a insuficiência renal crônica. É fundamental a identificação e o tratamento precoces desta condição clínica, prevenindo a ocorrência de doença renal em estágio terminal, com consequente necessidade de terapia de substituição renal. Há uma década, o controle da hipertensão renovascular era o objetivo primário no manejo de pacientes com doença renovascular. Atualmente, a meta está dirigida principalmente para a estabilização e a melhora da função renal, além do controle dos níveis pressóricos.

[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.

Objective performance goals of safety and blood pressure efficacy for clinical trials of renal artery bare metal stents in hypertensive patients with atherosclerotic renal artery stenosis

OBJECTIVE

To provide safety and performance goals for prospective single-arm trials of bare metal renal artery stenting in patients with resistant hypertension associated with high grade atherosclerotic renal artery stenosis.

BACKGROUND

To date, there have been no US Pre-Market Approval (PMA) bare metal renal stent device trials which have focused on improvement of blood pressure control as a primary effectiveness endpoint.

METHODS

Analysis of subject-level data from three large industry sponsored pre-market approval (PMA) trials was performed. Hypertensive patients (≥ 155 mmHg) with a ≥ 50% atherosclerotic renal artery stenosis were included. Thirty day and 9-month systolic and diastolic blood pressure measurements, renal function and 9-month duplex ultrasound assessment of renal artery patency were analyzed.

RESULTS

Initial data analysis of 600 patients from the 3 PMA trials identified 286 patients who met inclusion criteria. The mean baseline systolic blood pressure was 177.8 ± 19.3 mmHg with a mean 68.1% diameter renal artery stenosis. Nine months after successful stenting, the mean SBP was 156.7 ± 24.1 mmHg; the 9 month restenosis rate was 14.4%.

CONCLUSION

Based on the statistical modeling of these data and a priori established performance criteria, the co-primary endpoints of 9 month reduction in blood pressure and in-stent restenosis are proposed. The reduction in blood pressure will be analyzed as a continuous variable and will be compared to this performance goal.

Dramatic improvement of rapidly progressing acute renal failure and severe hypertension after bilateral renal artery stenting

In this case report, we describe an 83-year-old man with bilateral renal artery stenosis who had rapidly progressing acute renal failure and severe hypertension. These conditions improved dramatically after bilateral renal artery stenting. Renal artery stenosis can cause renal failure, hypertension, and heart failure, leading to a poorer life prognosis. If renal artery stenosis is found as a cause of acute renal failure, severe hypertension, or heart failure, it is useful to perform revascularization as soon as possible. Revascularization by stenting has a high success rate and is expected to improve the condition remarkably.

The uncertain value of renal artery interventions: where are we now?

Improved technology for detection of and endovascular procedures for renal artery stenosis due to atherosclerosis has been associated with increases in renal artery intervention. Hypertension with accelerated target organ injury, reduced kidney function, and episodic circulatory congestion in patients with renovascular disease predict reduced patient survival. Recent studies indicate that activation of pressor mechanisms depends upon hemodynamic gradients that are often overrated by visual estimates. Although activation of the renin-angiotensin system initiates renovascular hypertension, additional mechanisms perpetuate vascular remodeling and kidney injury that may not depend upon large vessel occlusion. Major advances in medical therapy have led to initiation of at least 4 major prospective trials comparing optimal medical therapy with or without stenting. Up to now, outcome data fail to support broad application of renal revascularization, including results from a recent large, prospective trial from the United Kingdom, despite small groups of patients that experience major clinical benefit. The ambiguity of these results partly reflect poor characterization of the severity of vascular lesions and competing risks within the population related to aging and pre-existing disease. Many patients currently undergoing renal artery interventions derive little net benefit and some are exposed to significant complications, including atheroembolic disease. Determining the appropriate role for renal artery interventions will depend on developing better methods for judging the role of large vessel occlusive disease regarding tissue oxygenation, activation of profibrotic pathways, and irreversible injury in the post-stenotic kidney.

Experience of stenting for atherosclerotic renal artery stenosis in a cardiac catheterization laboratory: technical considerations and complications

BACKGROUND

Atherosclerotic renal artery (RA) stenosis contributes to hypertension, renal insufficiency and end stage renal disease, and is independently associated with adverse cardiovascular events. Percutaneous renal intervention is efficacious in treating renovascular hypertension and may be effective in stabilizing or improving renal function, thereby reducing cardiovascular risk. However, high rates of procedural complications have been reported.

OBJECTIVES

To determine the nature and frequency of complications of percutaneous renal intervention using contemporary techniques and equipment in a high-volume cardiac catheterization laboratory.

METHODS

Consecutive patients undergoing attempted RA stenting for atherosclerotic RA stenosis in the cardiac catheterization laboratory at the Vancouver General Hospital (Vancouver, British Columbia) between June 2000 and March 2007 were enrolled in a prospective registry. Baseline clinical characteristics, procedural and technical information, and complications were recorded.

RESULTS

A total of 132 RAs were stented in 106 patients during 108 procedures. The procedural success rate was 100%, with no related death, myocardial infarction, nephrectomy or dialysis. Major complications included three pseudoaneurysms (2.8%) and acute deterioration in renal function in six patients (5.5%), although renal function returned to baseline in one patient at 12 months.

CONCLUSIONS

RA stenting can be successfully and safely performed using contemporary techniques, and the low complication rates described should be the minimum standard for contemporary trials evaluating RA stenting.

[Renal artery stenosis. Pathophysiology--diagnosis--therapy]

Renal artery stenosis (RAS) is both a common and progressive disease and its prevalence in patients > 65 years is 6.8%. In patients with known or suspected atherosclerosis undergoing coronary angiography, a frequency of even 11-23% is reported in the literature. Despite this high prevalence, there is an ongoing discussion about the indications for revascularization and it is currently unclear, whether renal artery revascularization reduces adverse cardiovascular and renal events. Nevertheless, the number of interventions for RAS is rising steadily, although up to 40% of patients do not profit from this intervention. This fact underlines the necessity of a thorough diagnostic work-up before intervention, integrating morphological and functional tests. For morphological evaluation, multislice computed tomography, magnetic resonance tomography or digital subtraction angiography can be done. In experienced centers, Doppler ultrasound can serve as an excellent functional tool, to assess the physiological relevance of an RAS, but also invasive measurements of pressure and flow provide valuable information about the significance of stenoses; however, these methods will have to be assessed with respect to their value to predict long-term outcome. Although percutaneous intervention of RAS is associated with a substantially lower risk of major adverse events as compared to surgery, by using contrast media this procedure holds the risk of deterioration of renal function and of a small number of procedure-dependent complications as well. Thus, a careful consideration of pros and cons of this procedure is mandatory.

Commentary: Shoot the renals!

Atherosclerotic renal artery stenosis (ARAS) is a growing dilemma. The condition is increasingly common and can promulgate hypertension and result in renal failure. However, patients with ARAS generally die owing to their coronaries or cerebral vessels. Intervention, by stenting or angioplasty is beloved and believed, but not proved. The American Heart Association has recently published guidelines regarding patients at high risk for ARAS who are potential candidates for revascularisation. Since this phraseology includes practically every patient with atherosclerosis, these guidelines appear ill advised.