The Society for Vascular Surgery practice guidelines on follow-up after vascular surgery arterial procedures

Although follow-up after open surgical and endovascular procedures is generally regarded as an important part of the care provided by vascular surgeons, there are no detailed or comprehensive guidelines that specify the optimal approaches with regard to testing methods, indications for reintervention, and follow-up intervals. To provide guidance to the vascular surgeon, the Clinical Practice Council of the Society for Vascular Surgery appointed an expert panel and a methodologist to review the current clinical evidence and to develop recommendations for follow-up after vascular surgery procedures. For those procedures for which high-quality evidence was not available, recommendations were based on observational studies, committee consensus, and indirect evidence. Recognizing that there are numerous published reports on the role of duplex ultrasound for surveillance of infrainguinal vein bypass grafts, the Society commissioned a systematic review and meta-analysis on this topic. The panel classified the strength of each recommendation and the corresponding quality of evidence on the basis of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system: recommendations were graded either strong or weak, and the quality of evidence was graded high, moderate, or low. The resulting recommendations represent a wide variety of open surgical and endovascular procedures involving the extracranial carotid artery, thoracic and abdominal aorta, mesenteric and renal arteries, and lower extremity arterial revascularization. The panel also identified many areas in which there was a lack of high-quality evidence to support their recommendations. This suggests that there are opportunities for further clinical research on testing methods, threshold criteria, and the role of surveillance as well as on the modes of failure and indications for reintervention after vascular surgery procedures.

Drug-eluting stents versus bare metal stents for the prevention of restenosis in patients with renovascular disease

AIMS

The aim of this study was to assess the impact of drug-eluting stents (DES) compared to bare metal stents (BMS) for the endovascular treatment of atherosclerotic renal artery stenosis (ARAS).

METHODS AND RESULTS

We retrospectively evaluated all of our endovascular BMS and DES implantations performed in de novo ARAS between 2000 and 2014 at our institution. The occurrence of in-stent restenosis (ISR) detected by ultrasound or angiography, kidney function, blood pressure (BP), and the number of antihypertensive drugs were analysed as endpoints. Overall, 338 renal arteries were treated in 298 patients. BMS were implanted in 163 (48%), and DES in 175 lesions (52%). Of the 175 lesions treated with DES, 55 (31%) were treated with a BMS-in-DES hybrid technique. For reasons of comparability, only lesions treated with balloon sizes of 4-6.5 mm were included in the final analysis. After 12 months, the rate of ISR >50% was 18.6% in the BMS group and 7.2% in the DES group (p=0.031). None of the BMS-in-DES-treated (hybrid) lesions developed ISR (hybrid technique vs. BMS only p=0.008, hybrid technique vs. DES only p=0.034). Systolic BP and number of antihypertensive drugs remained unchanged in the BMS group but declined in the DES group (p=0.02). Renal function significantly deteriorated in the BMS group (p=0.03) but did not change significantly in the DES group (p=0.188).

CONCLUSIONS

DES were superior to BMS in preventing ISR. Overall, the BMS-in-DES-technique (hybrid) achieved the lowest risk for ISR.

Atherosclerotic Renal Artery Stenosis and Hypertension: Pragmatism, Pitfalls, and Perspectives

For many years and even decades, a diagnostic work-up to look for a secondary form of hypertension, particularly of renovascular origin, has been a central tenet in medicine. Atherosclerotic renal artery stenosis is considered the most common cause of renovascular hypertension. However, advances in understanding the complex pathophysiology of this condition and the recently documented futility of renal revascularization bring into question whether atherosclerotic renal artery stenosis truly causes "renovascular hypertension." From a clinical point of view, a clear distinction should be made between hypertension associated with atherosclerotic renal artery stenosis and hypertension caused by renal artery stenosis-induced activation of the renin-angiotensin-aldosterone system. Most patients with atherosclerotic renal artery stenosis do not have a form of hypertension that is remediable or improved by angioplasty; to expose them to the cost, inconvenience, and risk of a diagnostic work-up add up to little more than a wild goose chase. However, with very few exceptions, medical therapy with antihypertensives and statins remains the cornerstone for the management of patients with atherosclerotic renal artery stenosis and hypertension.

Effect of renal artery revascularization on left ventricular hypertrophy, diastolic function, blood pressure, and the one-year outcome

OBJECTIVE

The study aimed to determine the potential interrelations between left ventricle mass (LVM), LV diastolic function, systolic blood pressure (SBP) and diastolic blood pressure (DBP) and cardiovascular events in patients undergoing renal artery stenting [corrected] (RAS).

METHODS

Prior to RAS, 3 and 12 months afterward, the change in LVM, left ventricular mass index (LVMI), diastolic function (E/A ratio, E' wave velocity, isovolumetric relaxation time [IVRT], E/E' ratio) on echocardiography and change in SBP and DBP on 24-hour monitoring were assessed in 84 patients, aged 63.7 ± 10 years, who underwent RAS for renal artery stenosis > 60%.

RESULTS

During 12 months, 12 (14.3%) cardiovascular (CV) events (five deaths) occurred. At 1 year, the mean LVM decreased from 179 ± 49 g to 141 ± 31 g (P < .001), LVMI in men decreased from 100 ± 20 g/m(2) to 79 ± 18 g/m(2) (P < .001), and the LVMI in women decreased from 96 ± 18 g/m(2) to 80 ± 17 g/m(2) (P < .001). No improvement in diastolic function parameters was seen. The mean SBP and DBP decreased from 133.5 ± 16.9 mm Hg to 127.9 ± 13.2 mm Hg (P = .007) and from 75.4 ± 10.2 mm Hg to 73.1 ± 8.8 mm Hg (P = .035), respectively. On multivariate logistic regression analysis, coronary artery disease (CAD) severity (relative risk [RR], 1.27; P = .023), smoking (RR, 1.29; P = .016), and baseline LVM (RR, 1.21; P = .07) were found as independent CV event risk factors. The independent factors associated with SBP and DBP improvement were grade of renal stenosis (RR, 1.28; P = .006), bilateral RAS procedure (RR, 1.17; P = .07), and baseline DBP value (RR, 1.74; P < .001). LVM reduction was associated with higher baseline ejection fraction (RR, 1.53; P < .001) and baseline LVM (RR, 1.7; P < 0.001). SBP and DBP value changes were independent of LVM change (r = 0.031; P = .796 and r = 0.098; P = .413, respectively).

CONCLUSIONS

RAS induced LVM and LVMI reduction, which is independent of the change in blood pressure. Baseline LVM is associated with higher CV event risk following RAS.

Critical review of indications for renal artery stenting: do randomized trials give the answer?

Significant renal artery stenosis (RAS) is a well accepted cause of deterioration of arterial hypertension and of renal insufficiency. Just recently, more interest has been focused on the impact of RAS on structural heart disease and patient survival. Technical improvements of diagnostic and interventional endovascular tools have lead to a more widespread use of endoluminal renal artery revascularization and extension of the indications for this type of therapy during the past 2 decades. Since the first renal artery angioplasties performed by Felix Mahler and Andreas Grüntzig, numerous single centre studies have reported the beneficial effect of percutaneous transluminal renal angioplasty, and since the early 1990's stenting of renal artery stenosis caused either by atherosclerosis or fibromuscular dysplasia. However, none of the so far published or presented randomized controlled trials (RCT) could prove a beneficial outcome of RAS revascularization compared with medical management. As a result of these negative trials including the recently presented ASTRAL trial, referrals to endovascular renal artery revascularization went down and moreover, reimbursement of these procedures became a matter of debate. This article summarizes the background and the limitations of the so far published and still ongoing controlled trials. Moreover, we discuss why well-designed registries might give important insight on the impact of endovascular revascularization of hemodynamically relevant atherosclerotic RAS.

RADAR - A randomised, multi-centre, prospective study comparing best medical treatment versus best medical treatment plus renal artery stenting in patients with haemodynamically relevant atherosclerotic renal artery stenosis

BACKGROUND

Prospective, international, multi-centre, randomised (1:1) trial to evaluate the clinical impact of percutaneous transluminal renal artery stenting (PTRAS) on the impaired renal function measured by the estimated glomerular filtration rate (eGFR) in patients with haemodynamically significant atherosclerotic renal artery stenosis.

METHODS

Patients will be randomised to receive either PTRAS using the Dynamic Renal Stent system plus best medical treatment or best medical treatment. Renal stenting will be performed under angiographic imaging. For patients randomised to best medical treatment the degree of stenosis measured by renal duplex sonography (RDS) will be confirmed by MR angio or multi-slice CT where possible. Best medical treatment will be initiated at randomisation or post procedure (for PTRAS arm only), and adjusted as needed at all visits. Best medical treatment is defined as optimal drug therapy for control of the major risk factors (blood pressure < or = 125/80 mmHg, LDL cholesterol < or = 100 mg/dL, HbA1c < or = 6.5%). Data recordings include serum creatinine values, eGFR, brain natriuretic peptide, patients' medical history and concomitant medication, clinical events, quality of life questionnaire (SF-12v2), 24 hour ambulatory blood pressure measurement, renal artery duplex ultrasound and echocardiography. Follow-up intervals are at 2, 6, 12 and 36 months following randomisation.The primary endpoint is the difference between treatments in change of eGFR over 12 months. Major secondary endpoints are technical success, change of renal function based on the eGFR slope change between pre-treatment and post-treatment (i.e. improvement, stabilisation, failure), clinical events overall such as renal or cardiac death, stroke, myocardial infarction, hospitalisation for congestive heart failure, progressive renal insufficiency (i.e. need for dialysis), need of target vessel revascularisation or target lesion revascularisation, change in average systolic and diastolic blood pressure, change in left ventricular mass index calculated from echocardiography, difference in the size of kidney (pole to pole length) measured by renal duplex sonography, total number, drug name, drug class, daily dose, regimen and Defined Daily Dose (DDD), of anti-hypertensive drugs, and change in New York Heart Association (NYHA) classification. Approximately 30 centres in Europe and South America will enrol patients. Duration of enrolment is expected to be 12 months resulting in study duration of 48 months.

TRIAL REGISTRATION

TRIAL REGISTRATION NUMBER

NCT00640406.