Renal Artery Stenting Research Articles

Renal frame count: a measure of renal flow that predicts success of renal artery stenting in hypertensive patients.

Renal artery (RA) stenting can improve control of hypertension yet predicting clinical response remains difficult. We sought to determine the role of the renal frame count (RFC) (number of angiographic frames for contrast to reach distal renal parenchyma after initial RA opacification) as a predictor of improvement in blood pressure (BP) after RA stenting. Renal flow was quantified in 68 consecutive patients (age 72.5 ± 9.1 years, 72% male) undergoing RA stenting for refractory hypertension (BP ≥ 140/90 mm Hg despite treatment with two or more antihypertensive medications) by measuring RFC pre-RA stenting. Significant renal artery stenosis (RAS) was defined as a stenosis ≥ 70% by visual estimation on angiography. Baseline and 6-month follow-up BP was recorded. Clinical response was defined by a drop in systolic blood pressure (SBP) >10 mm Hg on the same or fewer number of anti-hypertensive medications. Patients with RFC > 30 had SBP reduction (43.2 ± 25.7 mm Hg vs. 30.1 ± 31.3 mm Hg, P = 0.067), diastolic blood pressure reduction (9.1 ± 19.0 vs. -0.2 ± 13.4 mm Hg, P = 0.02), and mean arterial pressure reduction (23.8 ± 19.4 vs. 11.8 ± 16.1 mm Hg, P < 0.001) compared to patients with RFC ≤ 30. Furthermore, baseline RFC >30 was associated with a higher rate of clinical response to RA stenting (93.5% vs. 73%, P = 0.027). RFC can be used as a clinical predictor of response to RA stenting. RFC > 30 was associated with reduction in BP after RA stenting and was predictive of clinical response. RFC provides a useful intraprocedural tool in assessing the severity of RAS and predicts the likelihood of clinical response following RA stenting.

Atherosclerotic Renal Artery Stenosis: is there still a reason for renal revascularization?

Atherosclerotic Renal Artery Stenosis (ARAS) is a frequent problem in clinical practice. The disease is associated with three major clinical syndromes: ischemic nephropathy, hypertension and destabilizing cardiac syndromes. Although some case series showed a trend towards reduced rates of decline in renal function following renal stent placement, other studies suggested less convincing evidence of benefits.To date, randomized controlled clinical trials about optimal medical therapy versus renal artery stenting, designed to demonstrate the preservation of renal function after stenting, failed to show a benefit with respect to blood pressure and kidney function. It is still necessary to identify the subgroups that would benefit from the treatment. This review was developed to guide in the management of renal stenting and supports guidelines citing flash pulmonary edema as an indication for renal stenting in ARAS. Patients presenting a combination of rapidly declining kidney function and refractory hypertens...

Stenosi aterosclerotica dell'arteria renale: esiste ancora spazio per la rivascolarizzazione dell'arteria renale?

Abstract non disponibile

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Objective:In some guidelines congestive heart failure is an indication for renal artery stenting. We sought to determine, in patients enrolled with a history of congestive heart failure (CHF), the effect of renal artery stenting on clinical outcomes in the Cardiovascular Outcomes in Renal Atheroscle

PC4. Comparative Geometric Analysis of Renal Artery Anatomy Before and After Fenestrated or Snorkel/Chimney EVAR

Values in mean 6 standard deviation. D, Change from pre-op to post-op; NS, no Positive end-stent angle indicates vessel angulation with respect to the stent end Significant changes from pre-op to post-op (P < .05). Significant difference between LRA and RRA (P < .05). underwent computed tomography angiography before and after F-EVAR (n 1⁄4 21) or Sn-EVAR (n 1⁄4 20), which involved a total of 74 renal artery stents. Renal artery geometry was quantified using three-dimensional modelbased centerline extraction. Stented length was computed from vessel origin to stent end. Branch angle was computed relative to orthogonal configuration with respect to the aorta at vessel origin. End-stent angle was computed relative to distal native renal artery. The radius of curvature was defined by the circumscribed circle at the highest curvature within the proximal portion from the origin to the stent end, and distal portion from the stent end to first renal artery bifurcation. Results: Stented renal artery length, branch angle, end-stent angle, and maximum change in radius of curvature from preoperative to postoperative are presented in the Table. Sn-renals had greater stented length compared with F-renals (P < .02). From preoperative to postoperative, origins of the Sn-renals angled increasingly downward (P < .002), whereas F-renals angled increasingly upward (P < .002). End-stent angle of SnRRA increased from preoperative to postoperative (P < .00001), and Sn-RRA exhibited a greater magnitude change in end-stent angle compared with Sn-LRA (P < .05) and F-RRA (P < .0005). Radius of curvature decreased in distal Sn-RRAs (P < .02). Acute renal failure occurred in 9.8% of patients, and none required dialysis. Renal stent patency was 98.6% at mean follow-up of 13.7 months. Five type IA endoleaks were identified, prompting one secondary procedure. One renal artery reintervention was performed due to an asymptomatic kinked left renal stent. Conclusions: Stented renal arteries were angled more inferiorly after Sn-EVAR and superiorly after F-EVAR due to stent configuration. Sn-EVAR induced significantly greater angle change at the stent end and curvature change distal to the stent compared to F-EVAR due to greater angle change of the Sn-renals, although no difference in patency was noted. Sn-RRA exhibited larger endstent angle change from preoperatively to postoperatively compared to the Sn-LRA, likely because the presence of the IVC on the right side restricts motion of the proximal RRA. The occurrence of the kinked left renal stent is consistent with the proximal right renal artery being more mechanically supported by the IVC. Additional

Spontaneous isolated abdominal aortic dissection involving the celiac, superior mesenteric, inferior mesenteric, right renal, left iliac, and right superficial femoral arteries

A 55-year-old man presented to the emergency department after waking with severe back pain migrating to the abdomen, systolic blood pressure >230 mm Hg, and noncompliance with antihypertensive medications. Computed tomography angiography of the chest and abdomen showed an aortic dissection originating at the diaphragmatic hiatus and extending to the left external iliac and right superficial femoral artery (A and B). The dissection extended into the celiac and superior mesenteric arteries without malperfusion and extended into the inferior mesenteric artery with thrombosis (C). A complex intimal flap extended into the right renal artery, resulting in attenuation of the nephrogram (D). The patient was initially managed with intravenous antihypertensive (esmolol, clevidipine) medication, and the abdominal pain resolved. There was no evidence of bowel or lower extremity ischemia, and urine output was adequate. On hospital day 2, he developed paralysis of the lower extremities with preservation of sensation. He underwent an emergent stent graft (TAG; W. L. Gore & Associates, Flagstaff, Ariz) repair of the entry tear, and symptoms resolved. Two days after surgery, the paralysis returned and renal function decreased. A left renal artery stent (Complete SE; Medtronic, Minneapolis, Minn) was placed with minimal improvement. Fewer than 100 cases of isolated abdominal aortic dissection exist in the literature. Dissections extend distal to the common iliac artery in less than half of the cases and rarely extend into visceral arteries. More than one third of isolated abdominal aortic dissections occur with abdominal aortic aneurysms, 51% to 78% have hypertension, and the majority present with acute aortic symptoms. Presenting symptoms include abdominal pain (47%), back pain (23%), claudication/limb ischemia (17%), and paraplegia (3%); 17% are asymptomatic. Because of the small number of cases, no consensus exists on treatment. Options include open or endovascular repair and medical management. Surgical indications include rupture, visceral or limb ischemia, renal failure, visceral extension, refractory pain, and continued hypertensive crisis. The overall in-hospital mortality is 5%, as is the incidence of lower extremity neurologic symptoms. Some studies suggest that the long-term mortality is higher in patients who are medically managed, leading them to recommend a more aggressive surgical or endovascular approach and to propose that endovascular therapy be used when possible.

Event Rates in Randomized Clinical Trials Evaluating Cardiovascular Interventions and Devices

Randomized clinical trials (RCTs) are considered the gold standard for evidence-based medicine. However, an accurate estimation of the event rate is crucial for their ability to test clinical hypotheses. Overestimation of event rates reduces the required sample size but can compromise the statistical power of the RCT. Little is known about the prevalence, extent, and impact of overestimation of event rates. The latest RCTs on 10 preselected topics in the field of cardiovascular interventions and devices were selected, and actual primary event rates in the control group were compared with their respective event rate estimations. We also assessed what proportion of the nonsignificant RCTs was truly able to exclude a relevant treatment effect. A total of 27 RCTs randomizing 19,436 patients were included. The primary event rate in the control group was overestimated in 20 of the 27 RCTs (74.1%) resulting in a substantial relative difference between observed and estimated event rates (mean-22.9%, 95% confidence interval-33.5% to-12.2%; median-16.3%, 95% confidence interval-30.3% to-6.5%). Event rates were particularly overestimated in RCTs on biodegradable polymer drug-eluting coronary stents and renal artery stenting. Of the 14 single end point superiority trials with nonsignificant results, only 3 (21.4%) actually resulted in truly negative conclusions. In conclusion, event rates in RCTs evaluating cardiovascular interventions and devices are frequently overestimated. This under-reported phenomenon has fundamental impact on the design of RCTs and can have an adverse impact on the statistical power of these trials to answer important questions about therapeutic strategies.

Renal artery stenosis precipitates hyponatremic hypertensive syndrome and posterior reversible leukoencephalopathy.

Hyponatremic hypertensive syndrome (HHS) is an uncommon disorder usually encountered in the adult population with unilateral renal artery stenosis and is under-recognized in the pediatric population. A 19-month-old male presented with new-onset status epilepticus associated with neurological sequelae, and hypertension to a high of 248/150 mmHg. Lab work revealed significant hyponatremia, elevated peripheral renin activity, and increase in aldosterone and ADH levels. A diagnosis of HHS was made. Initial analysis revealed a high-grade proximal renal artery stenosis by magnetic resonance imaging (MRI) and angiogram. Electroencephalogram and an MRI of the brain demonstrated characteristic abnormalities of the left temporal-parietal regions consistent with posterior reversible leukoencephalopathy syndrome (PRES). The patient responded to right renal artery balloon dilation and stent placement. Since intervention and close blood pressure control with Amlodipine, the patient has been free of seizures and is neurologically intact. We report a case of malignant hypertension in a 19-month-old male secondary to renal artery stenosis with associated HHS and PRES. Prognosis of PRES in children with renal disease is excellent. Prompt intervention may offer near complete resolution of physiologic and symptomatic effects of HHS and PRES due to high-grade renal artery stenosis. This report was written with parental consent for de-identified case presentation and radiographs for the educational benefit of other medical professionals.

TCTAP A-169 Long-Term Outcomes After Percutaneous Transluminal Renal Artery Stenting for Atherosclerotic Renal Artery Stenosis in the Coronary Drug-Eluting Stent Era: A Japanese Single-Center Retrospective Study

We firstly examined the long-term outcomes after percutaneous transluminal renal angioplasty with stenting (PTRA) for atherosclerotic renal artery stenosis (ARAS) in a Japanese daily practice in the coronary drug-eluting stent (DES) era. This retrospective, non-randomized, single-center study was

Treatment of a recurrent renal artery stenosis and stent fracture using a drug eluting stent in a pediatric patient.

Renal artery obstruction is uncommon in the pediatric population and therefore represents a challenging diagnosis to ascertain and treat. While angioplasty and surgery have been used to treat it, stent implantation has been left mainly for adult use. In the following paper, we expose the case of an 8-year-old female who presented with severe arterial hypertension. Initially, the patient was evaluated and up to 5 antihypertensive medications were started. After complete evaluation, she was found to have severe right renal artery distal and proximal stenosis. She underwent recurrent angioplasties and then a bare metal stent (BMS) implantation, due to recurrence of stenosis. The original BMS developed a circumferential fracture, leading to a second stent implant, this time using a drug eluting stent (DES). She has been stable for 8years since the last intervention, although using 2 antihypertensive medications. The use of BMS and DES may add another tool in the armamentarium of the pediatric interventionist to treat these children with recurrent stenosis that fail angioplasty.

Bifurcation aortic stent graft placement in a patient with abdominal aortic aneurysm and single kidney with renal artery stenosis

Abdominal aortic aneurysm (AAA) is the most common true arterial aneurysm with an estimated prevalence of 4–9%. Bilateral renal artery stenosis, or stenosis to a solitary functioning kidney, merits specific consideration because of its additional contribution to fluid retention, loss of kidney function, and congestive heart failure. Abdominal aortic aneurysms are managed according to their diameter and the presence or absence of symptoms. Endovascular aneurysm repair (EVAR) is associated with a lower risk of perioperative morbidity compared with open repair for asymptomatic, symptomatic, and ruptured AAA. We report here a case of symptomatic infrarenal abdominal aortic aneurysm with a single kidney, with stenosis of the renal artery supplying the solitary kidney managed by us with renal artery stenting and endovascular repair of the abdominal aortic aneurysm.

Late mortality in females after endovascular aneurysm repair

BackgroundAbdominal aortic aneurysm (AAA) rupture is an adverse arterial remodeling event with high mortality risk. Because females have increased rupture risk with smaller AAAs (<5.5 cm), many recommend elective repair before the AAA reaches 5.5 cm. Elective repair improves survival for large AAAs, but long-term benefits of endovascular aneurysm repair (EVAR) for small AAAs in females remain less understood. The objective of this study was to identify if differences in late mortality exist between females undergoing elective EVAR at our institution for small and/or slow-growing AAAs compared with those who meet standard criteria. MethodsWe retrospectively analyzed all patients that underwent EVAR for infrarenal AAA from June, 2009–June, 2013. We excluded patients that were male, treated emergently or for iliac artery aneurysm, and that received renal and/or mesenteric artery stenting. Patients did not meet anatomic criteria if preoperative AAA diameter was <5.5 cm or enlarged <0.5 cm over 6 mo. Late mortality was assessed from the social security death index. ResultsThirty-six of 162 elective EVAR patients (22.2%) were female (mean follow-up, 37.2 mo). Twenty patients (55.6%) met AAA size and/or growth criteria, whereas 16 (44.4%) did not meet criteria. Despite comparable demographics, comorbidities, and complications, patients that did not meet criteria had higher late mortality (37.5% versus 5%; P = 0.03) with a trend toward increased reoperation rate (25% versus. 5%; P = 0.48). Meeting size and/or growth criteria decreased odds of late death (odds ratio, 0.09; 95% confidence intervals, 0.01–0.83). ConclusionsThere is increased late mortality in females receiving elective EVAR at our institution for small and/or slow-growing AAAs. This late mortality may limit the benefits of EVAR for this population.

Early Endovascular Treatment in Renal Transplant: A Case Report

Background: A 46-year-old female kidney transplant recipient developed acutely impaired graft function on the first postoperative day and received early endovascular treatment. Case report: The patient underwent living donor kidney transplantation from a sister in January 2011. She showed good diuresis during the early hours, followed by abruptly decreased urine output. Ultrasound examination suggested thrombosis of the intrarenal arteries or renal artery stenosis. Arteriography showed no stenosis at the site of anastomosis, but the presence of faint contrast filling the intrarenal arteries. She received intrarenal thrombolysis with 15 mg of recombinant tissue plasmin activator (rTPA), balloon angioplasty and a post anastomotic intra luminal renal artery stent with good perfusion and complete graft recovery. Conclusion: Early endovascular treatment is a possible therapeutic option in acute vascular renal transplant complications like intrarenal arterial thrombosis or renal artery stenosis. Excellent results were achieved with the procedure in the present case.

Fibromuscular Dysplasia

Fibromuscular dysplasia (FMD) is an idiopathic, segmental, nonatheromatous, and noninflammatory disease of the arterial walls, leading to stenosis, occlusion, aneurysm, dissection, and/or tortuosity of medium-sized arteries. Diagnosis is primarily radiographic with well-described histopathologic correlates. Though FMD commonly affects renal and cervical cerebrovascular arteries, FMD involving arteries of the upper and lower extremities, mesenteric arteries, and coronary arteries has also been described. This review covers epidemiology, etiology, and risk factors; histopathologic and radiographic classification; clinical presentation; differential diagnosis; radiographic evaluation; and treatment, including medical therapy, revascularization, and counseling. Tables outline the histologic and radiographic classification schemes for FMD and indications for renal artery and cerebrovascular revascularization in FMD based on the American Heart Association scientific statement. Figures show the radiographic appearance of FMD, coronary artery dissection, duplex ultrasonography of the renal artery, classic “string-of-beads” appearance, internal carotid artery, renal artery stent, and a small aneurysm. A management algorithm is provided. This review contains 7 figures, 4 tables, and 90 references.

Clinical Efficacy of Percutaneous Transluminal Renal Artery Stenting for the Treatment of Renovascular Hypertension Associated with Takayasu Arteritis

This study aims to observe and analyze the clinical efficacy of interventional therapy for patients with Takayasu arteritis (TA) experiencing renovascular hypertension (RH). Eight TA patients with RH underwent percutaneous transluminal renal artery stenting (PTRAS). Patients were followed up 1, 6, 12, and 24months postoperatively for levels of blood pressure, number of antihypertensive drugs being taken, levels of serum creatinine, and the presence of renal artery restenosis. All 8 patients were successfully followed up 1, 6, and 12months postoperatively, but 1 was lost to follow-up at 24months. All patients had significantly lower average blood pressure levels compared with those at baseline (P<0.05); treatment efficacy rates (recovery or improvement) at 1, 6, 12, and 24months were 94%, 90%, 80%, and 80%, respectively. The average number of antihypertensive drugs being taken was 3.5 at baseline, 1.0 at 1month, 0.5 at 6months, 1.0 at 12months, and 1.5 at 24months. Serum creatinine levels during the follow-up period were not significantly different from those at the baseline. No patient developed renal artery restenosis during the follow-up period. PTRAS is a safe and effective treatment for TA-associated RH, with a high technical success rate and a low complication rate. This interventional therapy can effectively control TA-related hypertension and can also preserve and even improve kidney function.

CRT-313 Feasibility of Robotic Percutaneous Renal Artery Revascularization

The safety and precision of PCI performed with the CorPath robotic system been demonstrated. Percutaneous treatment of ostial renal artery stenosis requires precise stent positioning. We examined the feasibility of robot assisted renal artery stent implantation. The CorPath robotic system was

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).

The year in cardiology 2014: peripheral circulation.

In 2014, the debate on the indication of revascularization in case of asymptomatic carotid disease continued, while another one regarding the use of surgery vs. stenting addressed some new issues regarding the long-term cardiac risk of these patients. Renal arteries interventions trials were disappointing, as neither renal denervation nor renal artery stenting was found associated with better blood pressure management or outcome. In contrast, in lower-extremities artery disease, the endovascular techniques represent in 2014 major alternatives to surgery, even in distal arteries, with new insights regarding the interest of drug-eluting balloons. Regarding the aorta, the ESC published its first guidelines document on the entire vessel, emphasizing on the role of every cardiologist for screening abdominal aorta aneurysm during echocardiography. Among vascular wall biomarkers, the aorta stiffness is of increasing interest with new data and meta-analysis confirming its ability to stratify risk, whereas carotid intima-media thickness showed poor performances in terms of reclassifying patients into risk categories beyond risk scores. Regarding the veins, new data suggest the interest of D-dimers and residual venous thrombosis to help the decision of anti-coagulation prolongation or discontinuation after the initial period of treatment for deep vein thrombosis.

A Case of Near Total Occlusion of the Renal Artery after Endovascular Abdominal Aortic Aneurysm Repair

Endovascular abdominal aortic aneurysm repair is a safe, durable, and effective procedure. However, complications could occur with stent graft devices. When the renal ostia become obstructed by this device, renovascular hypertension may result. In general, renal artery occlusion secondary to stent graft impingement remains uncommon. We herein describe a patient with renal atrophy, new-onset hypertension, and elevated serum renin and aldosterone levels following endovascular aneurysm repair. Blood pressure and the levels of renin and aldosterone were normalized by renal artery stenting.

Emergent unilateral renal artery stenting for treatment of flash pulmonary edema: fact or fiction?

Flash pulmonary edema is characteristically sudden in onset with rapid resolution once appropriate therapy has been instituted (Messerli et al., 2011). Acute increase of left ventricular (LV) end diastolic pressure is the usual cause of sudden decompensated cardiac failure in this patient population. Presence of bilateral renal artery stenosis or unilateral stenosis in combination with a single functional kidney in the susceptible cohort is usually blamed for this condition. We describe a patient who presented with flash pulmonary edema in the setting of normal coronary arteries. Our case is distinct as our patient developed flash pulmonary edema secondary to unilateral renal artery stenosis in the presence of bilateral functioning kidneys. Percutaneous stent implantation in the affected renal artery resulted in rapid resolution of pulmonary edema.