Management Of Renal Artery Stenosis Research Articles

CARDIOHEMODYNAMIC AND PROGNOSTIC SIGNIFICANCE OF RENAL ARTERY STENTING IN PATIENTS WITH CORONARY ARTERY DISEASE

The aim of the study is to evaluate cardiohemodynamic and prognostic significance of endovascular revascularization of renal arteries (ERRA) in patients with coronary artery disease (CAD).
 Materials and Methods. The authors examined 106 patients (84 men, 22 women; mean age 53±15). All the patients underwent both coronary angiography and renal artery angiography to verify chronic CAD. The authors analyzed the incidence and severity of arterial hypertension, the results of coronary and renal artery angiography, the outcomes of endovascular management of renal artery stenosis (RAS), and all-cause mortality rates. The follow-up period lasted for 10 years.
 Results. CAD was detected in 61 patients (58 %). Synchronous coronary and renal artery damage was detected in 12 patients (19.7 %), including hemodynamically significant renal artery stenosis (9 patients (14.8 %)). Eight patients underwent renal artery stenting. Arterial hypertension was observed in 58 of 61 patients (95.1 %) with verified CAD, including all the patients with synchronous coronary and renal artery damage. Seventeen patient (16 %) died during the monitoring period. During a 10-year period, 3 people (25 %) died from all causes in the group of RAS patients, while 14 people (14.8 %) died in the group of patients without RAS (χ=1.22; р=0.37). Twelve months after renal artery stenting, there was a decrease in systolic blood pressure load, a decrease in the number of unfavorable blood pressure profiles, and a decrease in end-diastolic dimension.
 Conclusions. In the medium term, ERRA is associated with a decrease in hypertensive load indices and systolic BP variability, an improvement of circadian blood pressure profiles, and a decrease in left ventricle end-diastolic and left atrium dimensions. Renal artery stenosis and ERRA did not significantly affect mortality over a 10-year follow-up.

Renal Artery Stenosis: Diagnostic and Management Problems

Renal artery stenosis is one common clinical problem. It has wide spectrum of pathophysiology with 3 most common clinical syndromes, ischemic nephropathy, hypertension, and cardiac destabilization syndrome. Aim: To date there was not any specific diagnostic criteria for renal artery stenosis. Method: Clinicians only used some clinical syndromes to guide the diagnostic possibility of renal artery stenosis. RADUS as one sensitive and specific diagnostic method, still had some disadvantages. Results: it gives false negative results in 10-20% of patients due to confounding factors such as operator capability, obesity, or abdominal gas distribution. CTA and MRA was excellent, but possessed some risks for the patient. Therefore, CTA was mostly recommended in patient with the planning of revascularization. Management of renal artery stenosis was still debated between optimal medical management and revascularization because the complexities of mechanisms underlying the renal artery stenosis. Because of the complicated pathophysiology of renal artery stenosis, revascularization could not entirely improve renovascular hypertension and nephropathy. Revascularization offered best results in fibromuscular dysplasia, although procedure related complication was still high. Revascularization, even though it might have high success rate in atherosclerotic renal artery stenosis, but the incidence of re-stenosis was also fairly high. Conclusion: Overall, revascularization was recommended in FMD, but should only be preserved for atherosclerotic renal artery stenosis after the failure of optimal medical management.

Manejo endovascular de la estenosis de la arteria renal en el trasplante renal

INTRODUCCIÓN: La estenosis de la arteria renal es la complicación vascular más frecuente del trasplante renal y una de las principales causas de pérdida del injerto y muerte prematura en los pacientes trasplantados. A pesar de ser potencialmente tratable, es frecuentemente infradiagnosticada, por lo que su diagnóstico precoz y manejo terapéutico adecuado resulta fundamental para evitar la pérdida de función renal.
 
 MATERIAL Y MÉTODOS: Analizamos retrospectivamente el caso de dos pacientes de 72 años trasplantados en nuestro centro en 2017. Ambos pacientes, con antecedentes de hipertensión arterial, cardiopatía isquémica crónica y enfermedad renal crónica terminal secundaria a nefroangioesclerosis y glomerulonefritis membranosa, respectivamente; presentaron un empeoramiento de la creatinina en el postoperatorio inmediato del trasplante renal. Ante este hallazgo y la evidencia de velocidades pico sistólicas >200 cm/s en la ecografía-doppler se sospechó una estenosis de la arteria del injerto, posteriormente confirmada con angiografía y angio-TC, respectivamente. Por lo que se realizó una revascularización percutánea e implante de stent.
 
 RESULTADOS: Se realizó la angioplastia con balón y colocación de stent, bajo anestesia local, obteniendo un buen resultado morfológico, sin complicaciones inmediatas. Tras el procedimiento ambos pacientes presentaron una mejoría progresiva de la función renal manteniendo un buen ritmo de diuresis, siendo dados de alta a los 8 y 11 días del mismo. Desde entonces, la función renal de ambos pacientes se ha mantenido estable presentando a los 12 meses un filtrado glomerular alrededor de 67 mL/min/1.73m2 y 60 mL/min/1.73m2, respectivamente. Sin evidencia de complicaciones tras 14 meses del procedimiento.
 
 CONCLUSIONES: La angioplastia con balón y colocación de stent en la estenosis de la arteria renal en el trasplante es una técnica segura y efectiva. Sin embargo, es necesaria una elevada experiencia para disminuir el número de complicaciones y optimizar los resultados de esta técnica.
 
 Palabras clave: trasplante renal, estenosis arterial, manejo mínimamente invasivo, cirugía endovascular.

Management of renal artery stenosis: What does the experimental evidence tell us?

Optimal management of patients with renal artery stenosis (RAS) is a subject of considerable controversy. There is incontrovertible evidence that renal artery stenosis has profound effects on the heart and cardiovascular system in addition to the kidney. Recent evidence indicates that restoration of blood flow alone does not improve renal or cardiovascular outcomes in patients with renal artery stenosis. A number of human and experimental studies have documented the clinical, hemodynamic, and histopathologic features in renal artery stenosis. New approaches to the treatment of renovascular hypertension due to RAS depend on better understanding of basic mechanisms underlying the development of chronic renal disease in these patients. Several groups have employed the two kidney one clip model of renovascular hypertension to define basic signaling mechanisms responsible for the development of chronic renal disease. Recent studies have underscored the importance of inflammation in the development and progression of renal damage in renal artery stenosis. In particular, interactions between the renin-angiotensin system, oxidative stress, and inflammation appear to play a critical role in this process. In this overview, results of recent studies to define basic pathways responsible for renal disease progression will be highlighted. These studies may provide the rationale for novel therapeutic approaches to treat patients with renovascular hypertension.

Ultrasound Doppler renal resistive index

The Doppler-derived renal resistive index has been used for years in a variety of clinical settings such as the assessment of chronic renal allograft rejection, detection and management of renal artery stenosis, evaluation of progression risk in chronic kidney disease, differential diagnosis in acute and chronic obstructive renal disease, and more recently as a predictor of renal and global outcome in the critically ill patient. More recently, evidence has been accumulating showing that an increased renal resistive index not only reflects changes in intrarenal perfusion but is also related to systemic hemodynamics and the presence of subclinical atherosclerosis, and may thus provide useful prognostic information in patients with primary hypertension. On the basis of these results, the evaluation of renal resistive index has been proposed in the assessment and management of patients with primary hypertension to complement other signs of renal abnormalities.

The rise and fall of renal artery angioplasty and stenting in the United States, 1988-2009

Optimal management of renal artery stenosis (RAS) remains unclear. Recent randomized controlled trials have shown no clear benefit with percutaneous transluminal angioplasty with or without stenting (PTRA/S) over medical management. We hypothesize that interventions for RAS are decreasing nationally. The Nationwide Inpatient Sample, 1988-2009, was used to identify patients with a diagnosis of renal artery atherosclerosis undergoing open surgical repair (bypass or endarterectomy) or PTRA/S. The rate of interventions, in-hospital death, and perioperative outcomes were analyzed over time. Additionally, we used individual state inpatient and ambulatory databases to better understand the influence of outpatient procedures on current volume and trends. We identified 308,549 PTRA/S and 33,147 open surgical repairs. PTRA/S increased from 1.9/100K adults in 1988 to 13.7 in 2006 followed by a decrease to 6.7 in 2009. Open surgical repair steadily decreased from 1.3/100K adults in 1988 to 0.3 in 2009. In 2009, PTRA/S procedures (6.4/100K adults) greatly outnumbered procedures done by open repair alone (0.1/100K), combined open renal and aortic repair (0.2/100K), and combined PTRA/S and endovascular aneurysm repair (0.3/100K). From 2005 to 2009 33,953 patients underwent PTRA/S in the states of New Jersey Maryland, Florida, and California combined. The total number of PTRA/S performed in the outpatient setting remained stable from 2005 (3.8/100K) to 2009 (3.7/100K), whereas the total number of inpatient procedures mirrored the national trend, declining from 2006 (7.9/100K) to 2009 (4.2/100K). PTRA/S had lower in-hospital mortality (0.9% vs 4.1%; P< .001) compared with open repair. PTRA/S patients were more likely to be discharged home (86.2% vs 76.3%; P< .001) and had a shorter length of stay (4.4 vs 12.3 days; P< .001). Mortality was higher after combined open renal and open aortic surgery compared to open repair alone (6.5% vs 4.1%; P< .001). Mortality was similar for combined PTRA/S and endovascular aneurysm repair compared with PTRA/S alone (1.2% vs 0.9%; P= .04). The performance of PTRA/S procedures for the management of RAS has decreased significantly after 2006. An increasing proportion of these procedures are performed in the outpatient setting. PTRA/S remains the dominant revascularization procedure for RAS with lower in-hospital mortality and morbidity than surgery.

Controversies in the management of the renal artery stenosis

Optimal management of renal artery stenosis has continued to remain elusive. The previous non randomized studies and registry data suggested a benefit of renal artery stenting. However, the recently completed randomized studies comparing renal stenting to medical management failed to show any benefit. These studies had some flaws in their design and methodology. In an appropriately selected patient population renal artery stenting may have a role. In addition, there might be some role of adjunctive therapies like antiplatelet medications and embolic protection. This review summarizes the current literature on this controversial topic.

RX Herculink Elite&amp;reg; renal stent system: a review of its use for the treatment of renal artery stenosis

The management of renal artery stenosis (RAS) remains controversial. While some evidence suggests that treatment with stent placement is beneficial, randomized trials have failed to demonstrate a significant benefit. Ongoing clinical trials should help to better define the role for stenting of RAS while avoiding limitations seen with earlier trials. When it comes to stenting for RAS, several stents have been used; however, many stents which have been used previously and which are still being used are biliary stents that are used “off-label.” These stents have typically come onto the market through the 510(k) pathway. To date, a total of five stents have been approved by the United States Food and Drug Administration for use in the renal arteries. Of the five stents that have received approval, the Bridge™ Extra Support (Medtronic Cardio- Vascular, Santa Rosa, CA) and the Palmaz® (Cordis Corporation, Bridgewater, NJ) stents are no longer available. Currently, the Express® SD (Boston Scientific, Natick, MA), Formula™ (Cook Medical, Bloomington, IN), and Herculink Elite® (Abbott Vascular, Santa Clara, CA) stents are Food and Drug Administration approved and available for use. The Herculink Elite is the most recently approved of the renal stents, having received approval in late 2011. The Herculink Elite stent is the only cobalt chromium stent approved for use in the renal arteries. Although trial data are limited and direct comparisons among renal stents is not possible, the Herculink Elite stent has demonstrated good performance. Additionally, the design of the Herculink Elite offers some advantages that may translate into improved outcomes.

Subintimal renal artery angioplasty in a case of renal artery stenosis leading to malignant hypertension

Endovascular intervention is an important consideration in the management of renal artery stenosis.

Medical therapy for renal artery stenosis

The management of renal artery stenosis remains controversial with randomized trials suggesting that revascularization is no better than medical therapy. Thus all patients with atheromatous renovascular disease should be treated with medical therapy. However optimal therapy has not been clearly defined by atheromatous renovascular disease trials; despite this, there are data to support the use of several pharmacologic agents among this group of patients. Such a regimen should include an angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker, a β-blocker, a statin and aspirin. Additional therapies will often be required and need to be individualized to a given patient based upon comorbid conditions.

Renal Revascularisation Therapy in 2011 – In Perspective

The management of renal artery stenosis (RAS) remains controversial. There is a large body of evidence from registries and cohort studies suggesting that revascularisation with stenting is beneficial in RAS; however, randomised trials of revascularisation versus medical therapy have failed to demonstrate that revascularisation improves outcome. Owing to significant methodological limitations, recent randomised trials have increased the controversy instead of resolving it, yet these trials cannot be disregarded. Currently, there appears to be a role for stenting in RAS, particularly among patients with at least moderate chronic kidney disease who seem to derive the greatest benefit from stenting. Additionally, there is probably some degree of blood pressure improvement; however, in most cases, stenting does not provide a cure. Thus, it is important that a physician evaluates each patient with RAS carefully and considers multiple issues to determine whether stenting would be beneficial.

Management of Renal Artery Stenosis: The Case for Intervention, Defending Current Guidelines, and Screening (Drive-By) Renal Angiography at the Time of Catheterization

There is little debate that an untreated significant obstruction of blood flow to the kidney, most often due to atherosclerosis, is potentially hazardous to the health of patients. The treatment of atherosclerotic renovascular disease has evolved over the past 20 years from open surgery with its inherent morbidity and risk of mortality to percutaneous endovascular treatment with stents. The current debate is on the question of which patients are offered any additional advantage by revascularization for renal artery stenosis over medications alone. The primary issue is patient selection, including the most appropriate screening strategies for renal artery stenosis, which must be balanced against the risk of procedure-related complications. The goal of this paper is to explore the most appropriate utilization of revascularization with renal stent placement.

Visceral Artery Interventions in Takayasu's Arteritis.

Takayasu's arteritis is an idiopathic chronic inflammatory disease affecting the aorta, its major branches and the pulmonary arteries. It leads to stenosis, occlusion, dilatation, and aneurysm formation in the involved vessels. Visceral arterial involvement occurs in 11 to 68% cases. Steno-obstructive lesions are most commonly seen and are usually symptomatic. Dilative and aneurismal lesions are uncommon and, when present, are usually clinically silent. Renal arteries are most commonly involved (24 to 68%), resulting in renovascular hypertension, whereas mesenteric arterial involvement is seen in 11 to 28% cases and is usually clinically silent. The assessment of disease activity is of utmost importance in its management as revascularization is best performed in the inactive phase. The disease activity can be assessed by clinical, biochemical, or radiological markers. The primary objectives of treatment include the control of disease activity by drug therapy, pharmacologic control of blood pressure (BP), supportive management and revascularization (surgical or endovascular) of the symptomatic ischemic territory. Surgical treatment is challenging due to the diffuse nature of the disease and involvement of adjacent aortic walls. It has a high incidence of anastomotic aneurysm formation (12 to 14%) and graft failure (20 to 40%) over time. Endovascular therapy (usually in the form of balloon angioplasty) has specific technical and procedural issues, but is safe and effective in the control of hypertension with success rates ranging between 80 to 96%. The overall complication rates are low. The cumulative 5-year patency rate for the management of renal artery stenosis is 67%. The use of stents is usually restricted as a bailout to treat obstructive dissection after angioplasty, due to a variety of reasons as their use may adversely affect the long-term outcome of treatment. Angioplasty is less effective in relieving obstruction in the mesenteric arteries and the outcomes are also infrequently reported.

Restenosis after renal artery angioplasty and stenting: Incidence and risk factors

Management of renal artery stenosis (RAS) with primary renal artery percutaneous angioplasty and stenting (RA-PTAS) is associated with a low risk of periprocedural death and major complications; however, restenosis develops in a subset of patients and repeat intervention may be required. We examined the incidence of restenosis after RA-PTAS and associations with clinical factors. Consecutive patients undergoing RA-PTAS for hemodynamically significant atherosclerotic RAS associated with hypertension or ischemic nephropathy, or both, between October 2003 and September 2007 were identified from a registry. Restenosis was defined using duplex ultrasound (DUS) imaging as a renal artery postintervention peak systolic velocity (PSV) >or=180 cm/s. The incidence and temporal distribution of restenosis was analyzed using survival analysis based on treated kidneys. Associations between clinical factors and recurrent stenosis were examined using proportional hazards regression. RA-PTAS was performed on 112 kidneys for atherosclerotic RAS during the study period. Initial postintervention renal artery DUS imaging confirming PSV <180 cm/s in 101 kidneys, which formed the basis of this analysis. Estimated restenosis-free survival was 50% at 12 months and 40% at 18 months. Decreased risk of restenosis was associated with preoperative statin use (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.16-0.74; P = .006) and increased preoperative diastolic blood pressure (DBP; HR, 0.70 per 10-mm Hg increase in preoperative DBP; 95% CI, 0.49-0.99; P = .049). No other factors assessed were associated with restenosis. Restenosis occurs in a substantial number of patients treated with RA-PTAS. Preoperative statin medication use and increased preoperative DBP are associated with reduced risk of restenosis. In the absence of contraindications, statins should be considered standard therapy for patients with atherosclerotic renal artery stenosis.

Inflammation in renal atherosclerotic disease

The study of renal atherosclerotic disease has conventionally focused on the diagnosis and management of renal artery stenosis. With the increased understanding of atherosclerosis as a systemic inflammatory process, there has been increased interest in vascular biology at the microvasculature level. While different organ beds share some features, the inflammation and injury in the microvasculature of the kidney has unique elements as well. Understanding of the pathogenesis yields a better understanding of the clinical manifestations of renal atherosclerotic disease, which can be very subtle. Furthermore, identifying the molecular mechanisms responsible for the progression of kidney damage can also direct clinicians and scientists toward targeted therapies. Existing therapies used to treat atherosclerotic disease in other vascular beds may also play a role in the treatment of renal atherosclerotic disease.

Traitement endovasculaire d’un anévrisme et d’une sténose de l’artère rénale secondaires à une dysplasie fibromusculaire

Limited data are available regarding the optimal management of renal artery stenosis (RAS) with a coexisting renal artery aneurysm. We present a case of high-grade RAS treated successfully with a stent-graft deployment resulting in the exclusion of an associated aneurysm. This therapeutic approach induced the sustained normalization of the blood pressure without antihypertensive medication and the correction of biochemical abnormalities secondary to the RAS.

Vaskuläre Rekanalisationstechniken: Nierenarterienstenosen

Decisive for the evaluation for radiological interventional therapy of renal artery stenosis, are the morphologic diagnostic by Duplex sonography, non-invasive cross-sectional angiography and digital subtraction angiography in addition to the anamnesis and clinical constellation. A standardized diagnostic algorithm and an evidence-based indication status contribute just as importantly to improvement of outcome as the implementation of uniform peri-interventional measures and a structured procedure for angiography, percutaneous transluminal renoangioplasty and follow-up. The aim of this article is to provide a practical introduction for the current radiological management of renal artery stenosis.

Management of renal artery stenosis - an update.

The role of the renal vasculature in eliciting renovascular hypertension (RVH) was established in 1934, when Goldblatt et al. [1] in a classical experimental study demonstrated that partial obstruction of the renal artery increased mean arterial blood pressure (BP). The pathophysiology of renal artery stenosis (RAS) is incompletely understood but has been postulated to be related to increased afterload from neurohormonal activation and cytokine release [2]. Atherosclerotic RAS (ARAS) is increasingly diagnosed in the expanding elderly population, which also has a high prevalence of arterial hypertension. There is still considerable uncertainty concerning the optimal management of patients with RAS. Many hypertensive patients with RAS have co-existing essential hypertension and furthermore, it is often difficult to determine to what degree the RAS is responsible for the impairment of renal function. There are three possible treatment strategies: medical management, surgery, or percutaneous transluminal renal angioplasty (PTRA) with or without stent implantation. The use of stents has improved the technical success rate of PTRA and also led to lower risk of restenosis, in particular for ostial RAS. PTRA with stenting has therefore replaced surgical revascularisation for most patients with RAS and has led to a lower threshold for intervention. The treatment of choice to control hypertension in fibromuscular dysplasia (FMD) is generally accepted to be PTRA [3]. In ARAS, on the other hand, the benefits with PTRA are less clear [4] and the challenge to identify which patients are likely to benefit from revascularisation remains unknown.

Durability of renal artery stents in patients with transrenal abdominal aortic endografts

The management of renal artery stenosis in patients with abdominal aortic aneurysms continues to be complex and technically challenging despite advances in endovascular therapy. There is growing concern about the durability of renal artery stents in the setting of transrenal abdominal aortic endografts. This study reports a single-center experience of renal artery stenting with transrenal abdominal aortic endografts for patients with renal artery stenosis. All patients undergoing endovascular abdominal aortic aneurysm repair preceded or followed by renal artery stent placement between January 1999 and December 2005 were retrospectively reviewed from a prospectively gathered endovascular database. Patients were surveyed after renal stent procedures with multidetector computed tomography angiography or duplex sonography. The surveillance data were analyzed for primary patency of the renal artery stent at 6 months, incidence of complications, need for secondary interventions, and changes in creatinine clearance (CrCl). Sixty-two renal artery stents were placed in 56 patients (44 men, 12 women) with a mean age of 77.3 years (range, 61 to 94 years). Forty-one were placed before the endograft procedure, eight were placed during the endograft procedure, and 13 were placed postoperatively. There were no major or minor complications related to the renal artery stent procedures. Transrenal aortic endografts were used in 44 of the 56 patients, and 12 had devices with infrarenal fixation. The mean follow-up was 18.5 months (range, 1 to 73 months). The 6-month primary patency, which could be evaluated for 51 renal artery stents, was 97.4% (37/38) in patients with transrenal fixation and 84.6% (11/13) in patients with infrarenal fixation. The overall rate of in-stent restenosis was 8.5% (4/47) in the transrenal fixation group and 20.0% (3/15) in the infrarenal fixation group. The overall occlusion rate was 2.1% (1/47) in the transrenal fixation group and 0% (0/15) in infrarenal fixation group. Five (83.3%) of six patients underwent successful treatment of in-stent restenosis with placement of a new stent in all five cases. CrCl decreased in the total group by 4.2 +/- 11.8 mL/min, by 4.7 +/- 12.0 mL/min in patients with transrenal fixation, and by 2.2 +/- 11.0 mL/min in patients with infrarenal fixation. The presence of a transrenal aortic endograft did not affect the outcome of the renal artery revascularization procedure in this cohort. Renal artery stenting in the presence of transrenal abdominal aortic endografts appears to be a safe procedure without adverse effect on renal artery stent patency or renal function.

Technology Insight: clinical role of magnetic resonance angiography in the diagnosis and management of renal artery stenosis

Noninvasive modalities, including duplex ultrasonography, renal scintigraphy, CT angiography and magnetic resonance angiography (MRA), may usefully contribute to diagnosis and treatment planning in patients with suspected renal artery stenosis. Important technical developments have increased the accuracy and feasibility of MRA for the detection of renal artery stenosis. A number of different MRA techniques can be applied to the study of renal arteries, but contrast-enhanced MRA represents the most valuable approach; several studies corroborate the high diagnostic accuracy of this technique, especially for the detection of atherosclerotic renal artery stenosis. A combined MRA protocol, which might include angiographic information provided by contrast-enhanced technique in addition to renal flow information derived from phase-contrast imaging, could help in classifying patients appropriately. Limitations of renal MRA include low accuracy in the evaluation of renal fibromuscular dysplasia and in the assessment of patients who undergo stenting of the renal arteries. This review describes the MRA techniques applied to the study of renal artery stenosis, including the technical features of current approaches and forthcoming developments. An overview of the clinical role of MRA, in conjunction with the other diagnostic modalities, in the identification and management of patients with renal artery stenosis, is also presented.