Feeds:
Posts
Comments

Posts Tagged ‘neurosurgical focus’

A new article has been published in Neurosurgical Focus discussing carotid stenosis, carotid artery stenting and carotid endarterectomy.  It discusses previous trial results including the limitations of previous results and controversies.  The authors also spend a significant portion of the article examining previous trial designs – and how these trial designs may have skewed some of the previously reported results.  Young et. al also discuss the implications of these results in both symptomatic and symptomatic patients with carotid stenosis and compares the outcomes of both stenting and surgery in these groups, including current and on-going studies.

Reminder:

CAS = carotid artery stenting

CEA = carotid endarterectomy (open surgery)

BMT = Basic Medical Treatment (medications)

It’s several pages long, so I have only re-posted partial sections below.

Kate C. Young, Ph.D., M.P.H.; Anunaya Jain, M.B.B.S. M.C.E.M.; Minal Jain, M.B.B.S.; Robert E. Replogle, M.D.; Curtis G. Benesch, M.D., M.P.H.; Babak S. Jahromi, M.D., Ph.D.  (2011, June).  Evidence-based Treatment of Carotid Artery Stenosis. Neurosurg Focus. 2011;30(6).

Abstract

Carotid atheromatous disease is an important cause of stroke. Carotid endarterectomy (CEA) is a well-established option for reducing the risk of subsequent stroke due to symptomatic stenosis (> 50%). With adequately low perioperative risk (< 3%) and sufficient life expectancy, CEA may be used for asymptomatic stenosis (> 60%). Recently, carotid angioplasty and stent placement (CAS) has emerged as an alternative revascularization technique. Trial design considerations are discussed in relation to trial results to provide an understanding of why some trials were considered positive whereas others were not. This review then addresses both the original randomized studies showing that CEA is superior to best medical management and the newer studies comparing the procedure to stent insertion in both symptomatic and asymptomatic populations. Additionally, recent population-based studies show that improvements in best medical management may be lowering the stroke risk for asymptomatic stenosis. Finally, the choice of revascularization technique is discussed with respect to symptom status. Based on current evidence, CAS should remain limited to specific indications.

Introduction

Stroke accounts for 1 in every 18 deaths in the US, and leaves nearly 30% of those afflicted permanently disabled.[3,49] Worldwide, stroke is a leading cause of disability and the third leading cause of death, with 5 million deaths reported annually.[7] In the US alone, each year nearly 800,000 individuals suffer a stroke, with one-quarter of those cases being recurrent strokes.[49] Despite advances in stroke prevention, imaging, treatment, and rehabilitation, the costs of care continue to increase. In 2008, the costs of stroke care were $65 billion/year.[16] The estimated cost of care for patients with stroke in 2010 is $73.7 billion, with overall costs expected to exceed $2 trillion by 2050.[49]

One of the most important causes of ischemic stroke is carotid atheromatous disease, representing approximately 20% of the total incidence of this type of stroke.[31] Severe carotid stenosis is the most important risk factor for recurrent stroke in symptomatic patients with carotid atheromatous disease. Several large randomized trials have shown marked early benefit from CEA. Timely CEA (within 2 weeks from onset of symptoms) results in an absolute risk reduction of 15.6% and a relative risk reduction of 52% over best medical management.[4,18,35,37,41] Results of these large-scale trials and their pooled patient-level meta-analyses have made CEA the standard of care in patients with severe (> 70%) symptomatic carotid stenosis, and have provided Level I/A evidence for decisions regarding symptomatic patients with lesser degrees of stenosis by demonstrating modest benefits of CEA for symptomatic 50%–69% stenosis, and no benefit for stenosis < 50%.[10,41] In contrast, patients with asymptomatic carotid stenosis have a vastly different natural history, with much lower upfront risks of stroke. Two large-scale randomized controlled trials have demonstrated modest benefits achieved over several years from treatment.[18,28] Indeed, significant improvements in stroke prophylaxis achieved by BMT have led to a reappraisal of CEA for asymptomatic stenosis, with current and upcoming trials of carotid revascularization now including an arm for BMT.[1,39]

Over the past decade, CAS has emerged as a potential alternative to CEA. The appeal of CAS has been driven in part by patient, physician, and hospital preferences for less invasive procedures, with underlying assumptions that this would lead to a reduction in complications, length of stay, and cost, although the latter 2 appear to not be borne out in practice.[25,28,38,51] The choice between CEA and CAS has therefore been primarily centered around which technique provides better clinical outcomes. Multiple CAS case series and registries have emerged, of mixed quality and with conflicting data, which will not be reviewed here. Unfortunately, large-scale randomized controlled trials comparing the 2 revascularization techniques have proven controversial, and have not convincingly identified a superior technique.[11,17,22,26,33,34,40,50] The most recent trial, CREST, was designed to avoid prior pitfalls and to reach definitive conclusions regarding choice of revascularization technique for carotid stenosis, although interpretation of its results has not been free of controversy either.[2,5]

Health care is undergoing a radical transformation. The economic environment has challenged health care organizations to deliver optimal services in the face of compromised cash flows, reduced resources, and declining margins. There is an overwhelming need for health care policy makers to audit current practices to ensure incorporation of cost-effective guidelines without compromising quality and outcomes of care. Our objective in this review of trials comparing CEA, CAS, and BMT in patients with carotid artery stenosis was to analyze existing evidence and cite comparative measures to consider while making such treatment decisions.

Young et al summarizes their findings:

Summary

Patients with symptomatic stenosis > 70% should undergo carotid revascularization. There is clear evidence that CEA is superior to BMT for such a group, with an absolute risk reduction of 15.6%. The benefits of CEA for 50%–69% stenosis, although significant, were modest compared with those in patients with 70% stenosis. Therefore, revascularization is recommended for 50%–69% symptomatic stenosis, with the understanding that aggressive lipid management and other antiplatelet agents have been added to the BMT regimen since NASCET and ECST were conducted, and may be useful in this population. Based on meta-analysis and recent data, CEA remains the procedure of choice for revascularization of symptomatic stenosis ≥ 50%; however, CAS is a potential alternative for patients with specific high-risk factors for CEA (for example, contralateral occlusion, radiation therapy, restenosis). Also, CAS has other, less well-defined indications, such as severe chronic obstructive pulmonary disease or the somewhat ambiguous “high risk” criteria.

We found that CEA has a modest benefit for asymptomatic stenosis, given at least a 3–5 year life expectancy after surgery. In contrast, CAS has a dubious benefit for asymptomatic stenosis; procedural morbidity and mortality rates approach or exceed 3%, whereas the procedural risks with CEA remain much lower. With the declining incidence of stroke due to asymptomatic lesions and the current natural history, SPACE-2 and other trials are well justified to compare BMT against CAS or CEA. The CAS procedure for asymptomatic stenosis should remain relegated to clinical trials, which should also include an arm for BMT.

What  does all of this mean:

Surgery is better than medications for severe stenosis, particularly in symptomatic patients.

Stenting is a viable option is symptomatic patients with high risks of surgical complications (complications as defined above).  Stenting should not be used in asymptomatic patients.

Basic medical treatment is a useful therapy, particularly in patients with borderline asymptomatic (50-60%) surgical stenosis, and combined with other treatments in patients with greater stenosis (or symptomatic).

Note:

Does this preclude stent technology in the future – No.  as stenting technology advances, stenting may become a more viable option for larger groups of people.

 

Advertisements

Read Full Post »