Renal Artery Revascularization Research Articles

Acute renal artery occlusion following infliximab infusion

We report the case of a 44-year-old male patient who presented with acute renal artery occlusion, 3 d after first injection of infliximab for steroid refractory attack of ulcerative colitis. Extensive work-up provided no evidence of predisposing factors for arterial thrombosis. Infliximab was thus suspected in the genesis of thrombosis, based on both intrinsic and extrinsic criteria. At month 3 after thrombosis with ongoing anticoagulation, angio-tomodensitometry showed complete revascularization of the left renal artery with renal atrophy. Renal function remained normal and the patient was still in steroid free remission on mercaptopurin monotherapy at maximal follow-up. Few thromboembolic events have been described with anti- tumor necrosis factor (TNF) agents, but it is the first case reported of renal artery thrombosis after infliximab infusion. In addition, we review thrombosis associated with anti-TNF agents.

Chronic furosemide administration blunts renal BOLD magnetic resonance response to an acute furosemide stimulus in patients being evaluated for renal artery revascularization

Background Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that is able to detect tissue oxygenation and has recently been utilized to evaluate renal function in patients with renal artery stenosis (RAS). Renal BOLD imaging is typically performed before and after a furosemide stimulus to assess kidney viability. Furosemide blocks the sodium-potassium2chloride transporter, an oxygen-dependent process, in the ascending loop of Henle located in the renal medulla. Presumably, kidneys that are able to decrease oxygen consumption and increase BOLD (T2*) signal in response to furosemide would be viable and benefit from revascularization procedures. A standard dose of 20mg of intravenous (IV) furosemide is administered to evaluate renal responsiveness (increased T2* signal intensity) and viability. However, little is known about the effect of prior exposure to furosemide on the ability of BOLD MR techniques to evaluate renal function.

Revascularization in Renal Artery Stenosis

The predominant cause of renal artery stenosis (RAS) is atherosclerosis. Clinical manifestations of atherosclerotic RAS are both direct (hypertension and kidney dysfunction) and indirect (increased cardiovascular events and mortality). However, in many cases, atherosclerotic RAS seems to be an incidental finding with no discernable effects. Antihypertensive medications such as renin-angiotensin-aldosterone system inhibitors, along with statins and aspirin, have significantly improved the medical treatment of atherosclerotic RAS. However, revascularization is still advocated in a variety of clinical settings such as the preservation of renal function, recurrent episodes of "flash" pulmonary edema, and in patients with refractory hypertension. Current management guidelines indicate "resistant hypertension" as an indication for renal artery revascularization. A large number of observational studies support revascularization for both control of high blood pressure and/or preservation of renal function. Unfortunately, the favorable effects of revascularization on these end points seen in the observational studies were not reproduced in randomized controlled trials compared to medical therapy alone. The ability for revascularization to improve control of congestive heart failure or to prevent hard cardiovascular end points (eg, myocardial infarction or stroke) has not been tested in the randomized clinical trials published to date. Hence, the efficacy of intervention remains controversial, which poses a dilemma, especially given the large number of elderly patients with resistant systolic hypertension.

Renal artery revascularisation can restore kidney function with absent radiotracer uptake

Children with renovascular hypertension often present with severe hypertension. Some children have severe obstruction of their renal arteries resulting in <10% relative function on [(99m)Tc]dimercaptosuccinic acid (DMSA) scan. Conventional treatment of these children has been nephrectomy of the poorly functioning kidney to normalise their blood pressure (BP). We describe three children aged 20 months to 9 years with severe renal artery stenosis and severe hypertension who had radionucleotide uptake of 0% in one kidney. In one case, no renal perfusion was demonstrated by duplex ultrasound scan. Significant recovery of relative renal function of 18 to 52% was achieved after revascularisation by percutaneous angioplasty or open surgery of the obstructed renal artery. These cases illustrate that scintigraphy alone cannot be used to predict salvageable function in children with renovascular disease.

Stenting in renovascular disease—good news for the heart?

The RASCAD trial investigated the potential benefit of renal artery revascularization versus medical therapy in patients with renal artery stenosis and coronary artery disease. Surprisingly, renal artery stenting seemed to convey no benefit on left ventricular mass. Has all been said and done about renal artery revascularization?

Percutaneous panvascular intervention in an unusual case of extensive atherosclerotic disease

It is common to see patients with atherosclerotic coronary disease and peripheral arterial disease in routine clinical practice. One needs to have a comprehensive and integrated multi-speciality approach and panvascular revascularization in such patients. We report a 54-year-old diabetic hypertensive male with extensive atherosclerotic coronary and peripheral arterial disease, who presented with congestive heart failure, claudication of both lower limbs and mesenteric ischemia. He underwent successful percutaneous panvascular revascularization of coronary, renal, mesenteric, aorto-iliac and superficial femoral arteries. Long-term patency of all the stents was also documented.

The heart in atherosclerotic renovascular disease

Atherosclerotic renovascular disease (ARVD) is associated with a high rate of cardiovascular disease and mortality. ARVD is an independent risk factor for adverse outcome in coronary artery disease and there is a correlation between the presence of ARVD and severity of cardiovascular disease. ARVD is the most common cause of secondary hypertension and can be found in up to half of elderly patients with chronic heart failure. Abnormal cardiac structure and / or function will be present in 95 % of ARVD patients, with left ventricular hypertrophy (LVH) and diastolic dysfunction the predominant abnormalities. These are likely to be due in part to over-activity of the renin-angiotensin pathway. Up to now, randomised trials have shown no benefit of renal artery revascularisation over medical therapy in terms of cardiovascular events but small case series clearly demonstrate situations where cardiac structure and function respond to revascularisation. Future strategies must focus on accurately identifying sub-groups of ARVD patients for whom revascularisation should be first line therapy.

A novel technique for renal stenting in the setting of type‐B aortic dissection

A type-B acute aortic dissection patient required renal artery revascularization for renal artery stenosis resulting from the compression by a false lumen. Renal artery stenting was complicated by unclear opacification of the ostia resulting from the collapsed true lumen of both renal artery and aorta. The use of the "Szabo" technique facilitated this procedure by allowing us to position the stent edge precisely at the ostium. This is the first report of this technique utilized in this lesion subset.

Percutaneous renal artery intervention versus medical therapy in patients with renal artery stenosis: a meta-analysis

Patients with renal artery stenosis are treated with percutaneous intervention, but randomised studies are inconclusive. We aimed to compare renal percutaneous revascularisation versus medical therapy. A systematic search for randomised controlled studies yielded three studies comparing renal angioplasty and two studies comparing renal angioplasty with stenting versus medical therapy, respectively. Six sets of data were extracted focusing on systolic and diastolic blood pressure as well as serum creatinine at follow-up. The five trials included 1,030 patients with renal artery stenosis. There was a trend toward, but no significant improvement in, systolic blood pressure (weighted mean difference [WMD] -2.76 mmHg, 95% confidence interval (CI) -5.71 to 0.18; p=0.07), diastolic blood pressure, (WMD -1.18 mmHg, 95% CI -2.69 to 0.32; p=0.12), or serum creatinine (WMD -7.26 mmol/L, 95% CI -14.99 to 0.47; p=0.07) in the patients who underwent percutaneous intervention compared to the medical therapy group. All but one trial showed at least a moderate overall bias risk. We did not find a significant improvement in blood pressure or renal function in patients with renal artery stenosis treated with renal artery revascularisation compared to medical therapy alone. However, trial quality was a limitation.

Surgical Treatment of Renal Artery Compression by Diaphragmatic Crus

Symptomatic compression of the renal artery by the diaphragmatic crus is a rare disorder. To our knowledge, renal artery compression by the diaphragmatic crus complicated with poststenosis aneurysm has not been reported. We present the case of a 28-year-old man with refractory hypertension. Extrinsic compression of the bilateral renal arteries and celiac artery and the aneurysm were proven by surgical exploration. We successfully performed left renal artery revascularization and renal autotransplantation in situ. Normal perfusion of the two bypass graft vessels was proven by computed tomography angiography.

Renal artery revascularization after unsuccessful percutaneous therapy: a single centre experience

This retrospective review describes the long time effect of surgical revascularization after unsuccessful early or mid-term failure of percutaneous transluminal renal angioplasty (PTRA). From January 1995 to January 2005, 60 out of 696 patients operated due to renal artery occlusive disease (17 fibromuscular dyplasia (FMD): mean age, 33.4years; 43 atherosclerotic disease (ASD): mean age, 62.46years) after unsuccessful PTRA underwent surgical revascularization for renal artery stenosis at our institution. The mean duration from failed PTRA to operation was 1.74years. Out of the 68 renal arteries, 44 were pretreated with angioplasty alone (19, FMD; 25, ASD), and 24 were treated with PTRA and stent (all ASD). Operative management, response of renal function and hypertension as well as survival were compared to the literature. Fifty-nine per cent (n = 40) of the renal arteries were treated by transaortic thrombendarterectomy, 37% (n = 25) by bypass. Thirty-day and in-hospital mortality was 0% in all pretreated patients; after a mean of 4.16years, it was 16.6% (only atherosclerotic). There was a significant decrease in systolic blood pressure values for all patients early after surgery as well as in follow-up. Creatinine remained stable in the patients with FMD, and there was an insignificant increase in creatinine level in the atherosclerotic patients. Hypertension was improved or healed in 32.5% of all pretreated patients, in cases with FMD in 54%, in atherosclerotic cases in 22.2%. Re-stenoses occurred in 26% of cases with FMD and in 18% of patients with atherosclerotic RAS. Surgical renal artery revascularization after failed PTRA is feasible and safe and systolic blood pressure can be lowered. The higher rate in re-stenoses in both the literature as well as in our own experience may be explained by the alterations in the renal artery after interventional treatment.

Acute renal artery occlusion: making the case for renal artery revascularization

Atherosclerotic renal artery disease is a common disease entity that may be identified in patients with difficult-to-control hypertension and/or chronic kidney disease but is probably underdiagnosed. Current evidence from both observational and randomized studies offers mixed results regarding the support for renal artery revascularization. There is lack of equipoise with regard to the efficacy of renal artery revascularization among the interventional and renal communities, as well as disagreements on the appropriate endpoints to measure in clinical trials, which have led to selection bias confounding the scant available data. We report a patient who does not fit any clinical trial inclusion criteria with acute on chronic kidney injury and new-onset heart failure whose symptoms and renal function improved significantly after renal artery intervention.

A Novel Approach to the Management of an Inflammatory Abdominal Aortic Aneurysm Associated With Crossed-Fused Renal Ectopia

Crossed-fused renal ectopia is a rare anomaly that poses a therapeutic challenge in the management of abdominal aortic aneurysms (AAAs). Such challenges include preservation of renal blood flow in the setting of multiple aberrant renal arteries and ureteral anomalies. Several surgical approaches to this dilemma, including the use of traditional surgical techniques, have been described in the literature. We describe a novel approach to the management of a 7-cm inflammatory AAA associated with crossed renal ectopia with fusion. During routine surveillance computed tomography angiography (CTA) in a 63-year-old man, a rapidly enlarging AAA with new inflammatory changes was detected. The aneurysm had increased in size from 4.8 to 7 cm over a period of 6 months. At the time of presentation, he was found to be hemodynamically stable. Findings from the laboratory tests conducted at the time of admission were normal, with a baseline glomerular filtration rate of 91.2 mL/min and creatinine of 1. The CTA revealed significant thickening of the aortic wall, suggestive of aortic inflammation, the presence of crossed renal ectopia with fusion, and numerous anomalous renal arteries. We identified two right renal arteries arising from the proximal aneurysm sac and three left renal arteries arising from the common iliac arteries. Given the aortic inflammation, an open repair approach was considered high risk compared with an endovascular aneurysm repair (EVAR). However, given the uncharacteristic arterial anatomy, a staged surgical and endovascular management option was selected. We performed an aortic debranching and renal artery revascularization, followed by an EVAR. We preserved renal function and excluded the aneurysm. The patient was discharged on the postoperative day 6 without periprocedural complications. A CTA was performed at 1- and 6-month follow-up period. This revealed a type 2 endoleak, which was confirmed by MR angiography. However, the aneurysm diameter had decreased in size from 7 to 6.3 cm in 1 month, and from 6.3 to 5.5 cm in 6 months. No further intervention was performed. Inflammatory AAAs associated with crossed-fused renal ectopia can be successfully managed with aortic debranching and renal artery revascularization followed by an EVAR. This epitomizes the growing role for advanced endovascular therapies in conjunction with open surgical techniques.

Endovascular Repair of Acute Symptomatic Pararenal Aortic Aneurysm With Three Chimney and One Periscope Graft for Complete Visceral Artery Revascularization

To describe a modified endovascular technique for complete revascularization of visceral and renal arteries in symptomatic pararenal aortic aneurysm (PRAA). Arterial access was surgically established in both common femoral arteries (CFAs) and the left subclavian artery (LSA). Revascularization of the left renal artery, the celiac trunk, and the superior mesenteric artery was performed through one single sheath via the LSA. Suitable covered stents were put in the aortic branches but not deployed. The right renal artery was accessed over the left CFA. Due to the longitudinal extension of the presented aneurysm two stent-grafts were introduced via the right CFA. After deploying the aortic stent-grafts, all covered stents in the side branches were deployed consecutively with a minimum overlap of 5 mm over the cranial and caudal stent-graft edges. Simultaneous ballooning was performed to fully expand all stent-grafts and warranty patency. This is the first report in the literature of chimney grafting in PRAA for complete revascularization of visceral and renal branches by using more than two covered stents introduced from one side through one single sheath. However this technique is modified, it should be used only in bailout situations when branched stent-grafts are not available and/or surgery is not suitable.

Is There an Indication for Embolic Protection in Renal Artery Intervention?

The role of endovascular treatment of atherosclerotic renal artery disease is uncertain, particularly after the publication of the Angioplasty and Stenting for Renal Artery Lesions trial and other randomized trials. These trials have shown that nonselective treatment of patients with renal artery stenosis does not result in a benefit when compared with best medical therapy. However, all trials have identified a subgroup of patients who do respond favorably to revascularization. In particular, patients with a degree of chronic renal insufficiency, critical renal artery stenosis, and a recent decline in renal function are likely to respond positively to revascularization. Endovascular treatment of renal artery stenosis must be performed safely, particularly in the high-risk patient group with background chronic renal insufficiency. Atheroembolization occurs during renal artery revascularization, as demonstrated by ex vivo studies and the high embolic yield obtained in published series of protected renal artery revascularization. The evidence supporting embolic protection includes single-center series wherein excellent results for renal function preservation have been reported. One small, randomized, controlled trial demonstrated a significant benefit if both embolic protection and abciximab were used. There are unique demands on an embolic protection device in the renal artery circulation and a dedicated device has not been developed. Both distal filters and occlusion balloons have been successfully used. Both devices can normally be primarily passed through the stenosis, allowing the remainder of the procedure to be protected. Filters have the advantage of maintaining renal perfusion throughout the procedure. Distal occlusion balloons can capture embolic particles of all sizes although the clinical advantage is uncertain.

Homocysteine-Lowering and Cardiovascular Disease Outcomes in Kidney Transplant Recipients

Background— Kidney transplant recipients, like other patients with chronic kidney disease, experience excess risk of cardiovascular disease and elevated total homocysteine concentrations. Observational studies of patients with chronic kidney disease suggest increased homocysteine is a risk factor for cardiovascular disease. The impact of lowering total homocysteine levels in kidney transplant recipients is unknown. Methods and Results— In a double-blind controlled trial, we randomized 4110 stable kidney transplant recipients to a multivitamin that included either a high dose (n=2056) or low dose (n=2054) of folic acid, vitamin B6, and vitamin B12 to determine whether decreasing total homocysteine concentrations reduced the rate of the primary composite arteriosclerotic cardiovascular disease outcome (myocardial infarction, stroke, cardiovascular disease death, resuscitated sudden death, coronary artery or renal artery revascularization, lower-extremity arterial disease, carotid endarterectomy or angioplasty, or abdominal aortic aneurysm repair). Mean follow-up was 4.0 years. Treatment with the high-dose multivitamin reduced homocysteine but did not reduce the rates of the primary outcome (n=547 total events; hazards ratio [95 confidence interval]=0.99 [0.84 to 1.17]), secondary outcomes of all-cause mortality (n=431 deaths; 1.04 [0.86 to 1.26]), or dialysis-dependent kidney failure (n=343 events; 1.15 [0.93 to 1.43]) compared to the low-dose multivitamin. Conclusions— Treatment with a high-dose folic acid, B6, and B12 multivitamin in kidney transplant recipients did not reduce a composite cardiovascular disease outcome, all-cause mortality, or dialysis-dependent kidney failure despite significant reduction in homocysteine level. Clinical Trial Registration— http://www.clinicaltrials.gov . Unique identifier: NCT00064753.

Hybrid One-Stage Approach to Extensive Atherosclerotic Aneurysm of Thoracoabdominal Aorta

We report a 62-year-old man with an atherosclerotic Crawford type II aneurysm involving both common iliac arteries who underwent surgical revascularization of the visceral vessels and renal arteries from the ascending aorta and subsequent endovascular aneurysmal exclusion. Computed tomography imaging at 2 years showed complete exclusion of the aneurysm throughout the thoracoabdominal aorta, confirming the successful antegrade revascularization of visceral vessels and renal arteries. A hybrid approach to thoracoabdominal aneurysms using antegrade visceral and renal revascularization from the ascending aorta before endovascular repair is technically feasible and might constitute an attractive alternative to conventional surgical treatment.

Assessment of renal artery stenosis using both resting pressures ratio and fractional flow reserve – Relationship to angiography and ultrasonography

Background. Clinical benefit from renal artery revascularization remains controversial, probably because of inaccurate stenosis severity assessment. Objective. The aim of the study was to evaluate resting translesional pressures ratio and renal fractional flow reserve (rFFR) in relation to angiography and Doppler duplex ultrasonography in patients with at least moderate renal artery stenosis (RAS). Methods. 44 hypertensive patients (48% of males, mean age 65 years) with at least moderate RAS were investigated. Translesional systolic pressure gradient (TSPG), resting Pd/Pa ratio (the ratio of mean distal to lesion and mean proximal pressures) and hyperemic rFFR – after intrarenal administration of papaverine – were evaluated. Quantitative angiographic analysis of stenosis severity was performed including minimal lumen diameter (MLD) and percent diameter stenosis (DS) assessment. Renal/aortic ratio (RAR), resistive index (RI) and deltaRI (side-to side difference) were obtained in Doppler-duplex ultrasonography. The predictive value of selected variables was calculated using receiver-operating characteristics curves. Results. Mean Pd/Pa ratio was 0.86 ± 0.12 and decreased to 0.79 ± 0.13 after papaverine administration. Both Pd/Pa ratio and rFFR strongly correlated with TSPG (r = −0.92, p < 0.0001 and r = −0.88, p < 0.0001, respectively) and moderately with MLD (r = 0.62, p < 0.0001 and r = 0.66, p < 0.0001) and DS (r = −0.63, p < 0.0001 and r = −0.70, p < 0.0001). To identify more than 70% RAS, considered severe, the most predictive cut-off values were 0.93 for Pd/Pa ratio and 0.80 for rFFR. Conclusions. Mean Pd/Pa ratio and rFFR strongly correlated with angiographic data and in less pronounced manner with ultrasound parameters reflecting intrarenal blood flow. The best accuracy cut-off points for severe RAS predicting were 0.93 and 0.80, respectively.

Renal artery revascularization in a patient with abdominal aortic coarctation using the Riolan anastomosis as feeding vessel

Renal artery revascularization in a patient with abdominal aortic coarctation using the Riolan anastomosis as feeding vessel

The Effect of Revascularization of Atherosclerotic Renal Artery Stenosis on Coronary Flow Reserve and Peripheral Endothelial Function

Background: Patients with atherosclerotic renovascular disease (ARVD) are at increased risk of heart disease because of associated hypertension, coronary artery disease, cardiac failure and chronic kidney disease. Although suggested to be beneficial, the cardiac effects of renal artery revascularization have not been well characterized. Our aim was to analyze the effects of percutaneous dilatation of renal artery stenosis (RAS) in ARVD patients on coronary and peripheral vascular function. Methods: Nineteen ARVD patients [11 females and 8 males, age at study entry (mean ± SD) 69 ± 10 years] were treated by dilatation of unilateral (n = 9) or bilateral (n = 10) RAS, mainly because of uncontrolled or refractory hypertension. The patients were studied before and after the procedure (103 ± 29 days). They underwent echocardiography and peripheral artery endothelial function testing using flow-mediated dilatation (FMD) of brachial artery at rest and during reactive hyperemia. Myocardial blood flow was measured using quantitative PET perfusion imaging at baseline and during dipyridamole-induced hyperemia. Results: Peripheral endothelial function, tested by FMD, as well as systolic blood pressure and left ventricular mass were improved in patients with bilateral RAS. However, myocardial perfusion and coronary flow reserve (CFR) did not change after the RAS dilatation. Conclusion: This is the first study to analyze the stage of myocardial perfusion and CFR in ARVD patients. Although peripheral endothelial function, systolic blood pressure and left ventricular hypertrophy were improved in patients with bilateral RAS by revascularization of RAS, it did not have any effect on coronary perfusion.