Surgery Section - Extracranial Carotid Angioplasty/Stenting

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

Carotid angioplasty and stenting is the insertion of a stent (wire-mesh tube) into a narrowed carotid artery.   A catheter (a long hollow tube) is inserted into the groin artery and guided through the arteries to the narrowing in the carotid artery. A balloon at the end of the catheter is inflated to push open the narrowed area, and a metal stent  is inserted to keep this area from narrowing again.  The procedure is performed with the patient fully awake and without sedation.  At present, most practitioners also use a distally placed embolic protection (DEP) device that is designed to reduce the risk of stroke caused by thromboembolic material dislodged during CAS. Carotid angioplasty is rarely performed without stent placement.

The U.S. Food and Drug Administration (FDA) has approved carotid artery stents and DEP devices from various manufacturers:

• ACCULINK™ and RX ACCULINK™ carotid stents and ACCUNET™ and RX ACCUNET™ cerebral protection filters, Guidant Corp. (approved August 2004)
• Xact® RX carotid stent system and Emboshield® embolic protection system, Abbott Vascular Devices (approved September 2005)
• Precise® nitinol carotid stent system and AngioGuard™ XP and RX emboli capture guidewire systems, Cordis Corp. (approved September 2006)
• NexStent® carotid stent over-the-wire and monorail delivery systems, Endotex Interventional Systems; and FilterWire EZ™ embolic protection system, Boston Scientific Corp. (approved October 2006)

On June 6, 2008, the FDA issued a recall of the Boston Scientific NexStent® carotid stent over-the-wire and monorail delivery system. It was noted that the tip of this stent system had a tendency to detach during the procedure. The concern was that this may lead to increased procedure time, cause vessel wall damage, stroke and/or emergency surgery to remove the detached tip.

• ProtégéRx® and SpideRx®, ev3 Inc, Arterial Evolution Technology. (approved January 2007)

Each FDA-approved carotid stent system is indicated for combined use with a DEP device to reduce risk of stroke in patients at high risk for perisurgical complications from CEA and who are symptomatic with >50% stenosis, or asymptomatic with >80% stenosis.

Note:This policy does not address percutaneous angioplasty and stenting of intracranial or venous vessels, which are addressed in separate policies (see Cross References below).

Policy/Criteria

Carotid angioplasty with or without associated stenting and distal embolic protection is considered investigational.

Position Statement

The alternative to CAS is open carotid endarterectomy, which is currently considered the standard treatment for patients with blockage of the carotid artery (stenosis). There is insufficient evidence to draw conclusions about the benefits of CAS as a treatment for stenosis of the carotid artery.

• There are no long-term data from well-designed randomized controlled clinical trials demonstrating that CAS is equally effective or better than CEA.
• Available evidence does not demonstrate that CAS, compared to CEA, is performed with acceptable periprocedural stroke/death rates or that it provides a net health benefit to patients at high medical risk.
• While there is limited evidence to suggest that CAS may be beneficial in the group of patients at high surgical risk due to complications of anatomy and comorbid conditions, present evidence has not clearly differentiated outcomes for this subgroup according to symptomatic status.

Effectiveness

In order to determine the effectiveness of CAS, it must be compared to CEA, the current standard of care. Outcomes of particular interest include stroke, death, and morbidity assessed periprocedurally and during follow-up. Treatment durability is measured by the need for repeat interventions over the next several years. A recent report from the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology emphasized the importance of low perisurgical mortality: <3% for interventions used to reduce stroke risk in asymptomatic patients with greater than 60% stenosis, and <6% for interventions used to reduce stroke risk in symptomatic patients with greater than 50% stenosis of the carotid artery. (17)

Cochrane Reviews

The 2007 Cochrane Review is an update to their prior 2004 review and states,” The data are difficult to interpret because the trials are heterogeneous (different patients, endovascular procedures, and duration of follow up)….trials were stopped early, perhaps leading to an over-estimate of the risks of endovascular treatment. (15, 18) The pattern of effects on different outcomes does not support a change in clinical practice away from recommending carotid endarterectomy as the treatment of choice for suitable carotid artery stenosis.”(18) The Cochrane Review assessed 12 randomized trials that met their inclusion criteria. Three primary examples were the SAPPHIRE 2004 (3), SPACE 2006 (4), and EVA-3S 2006 (5) trials. The studies assessed had many common flaws:

• There were no well designed long-term trials that show CAS is as good or better than CEA. CEA has long-term data to prove durability of results up to 13 years. (3-5, 15, 18)
• All studies contained significant heterogeneity (different patients, endovascular procedures, and duration of follow up) which made it difficult to interpret data. (3-5, 15, 18)
• All studies involved highly selected lesions and patients which may have falsely decreased the complication rates within the studies. (3-5, 15, 18)
• Studies were stopped early due to recruitment, safety, or futility issues. (3-5, 15, 18)
• Partial or no intention-to-treat (ITT) analysis was done which may have biased results. (3, 5, 15, 18)
• Treatment efficacy was possibly confounded with the use of antiplatelet medications before, during, and post treatment. (3-5, 15, 18)
• Cumulative periprocedural death, stroke, and myocardial infarction (MI) rates for CAS were not within accepted standards of 3% or less for asymptomatic patients and 6% or less for symptomatic patients. (3-5, 15, 18)

Subsequent to the publication of the Cochrane Review, a 3-year follow-up of patients enrolled in the original SAPPHIRE trial reported no significant difference between CEA and CAS in outcomes. (25) However, due to the high 30-day periprocedural event rates in both of the CEA and CAS arms, the 3-year results were not informative.

Meta-Analyses

Each systematic meta-analysis reported pooled results from randomized controlled trials for all participants combined, including symptomatic and asymptomatic patients, with high and low surgical risk. Comparing CAS to CEA, the relative increase in 30-day stroke and death risk were similar in all meta-analyses. (19-21) Although the meta-analyses are limited by pooling results from heterogeneous patient samples, authors consistently concluded that evidence favors CEA over CAS. Authors state that more randomized controlled studies are needed with long-term outcomes. These results are consistent with the 2007 BlueCross BlueShield Association Technology Evaluation Center (TEC) assessment as well. (2, 6)

Registry Data

There have been a number of published reports from registry data. (7-14, 22-24) Conclusions from this type of data are unreliable due to:

• Lack of randomization.
• Lack of control for various forms of bias (e.g. inclusion, reporting, recall, and investigator bias’). 
• Lack of control for comparable patient characteristics.
• Lack of consistent parameters as well as systems used.
• Lack of control for co-treatments.
• Lack of durability with long-term outcomes.

Guidelines

FDA Approval Conditions

The Precise® and AngioGuard™ devices were studied in a randomized, controlled trial (the SAPPHIRE trial). Other devices were approved based on uncontrolled, single-arm trials or registries, and comparison to historical controls. The FDA has mandated postmarketing studies for these devices, including longer follow-up for patients already reported to the FDA and additional registry studies, primarily to compare outcomes as a function of clinician training and facility experience.

Safety

Long-term safety and complication rates for CAS are unknown compared to other therapies; however, several adverse reactions are reported in the published literature including:

Death

Stroke

Myocardial Infarction

Intracerebral bleed

Restenosis

Neurological events

Hyper-perfusion post procedure

References

1. BlueCross BlueShield Association Medical Policy Reference Manual, Policy No. 7.01.68
2. 2004 BlueCross BlueShield Association Technology Evaluation Center (TEC) Assessment: Angioplasty and stenting of the cervical carotid artery with distal embolic protection of the cerebral circulation. T-15
3. Yadav JS, Wholey MH, Kuntz RE et al. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med 2004;351(15):1493-501
4. Ringleb PA, Allenberg J, Bruckmann H et al. 30 day results from the SPACE trial of stent-protected angioplasty versus carotid endarterectomy in symptomatic patients: a randomized non-inferiority trial. Lancet 2006;368(9543):1239-47
5. Mas JL, Chatellier G, Beyssen B et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med 2006;355(16):1660-71
6. 2007 BlueCross and BlueShield Association Technology Evaluation Center (TEC) Assessment:  Angioplasty and Stenting of the Cervical Carotid Artery with Embolic Protection of the Cerebral Circulation. T-1
7. Hobson RW 2nd. Update on the Carotid Revascularization Endarterectomy versus Stent Trial (CREST) protocol. J Am Coll Surg 2003;194(1 suppl):S9-14
8. Coppi G, Moratto R, Silingardi R et al. PRIAMUS—proximal flow blockage cerebral protection during carotid stenting: results from a multicenter Italian registry. J Cardiovasc Surg (Torino) 2005;46(3):219-27
9. White CJ, Iyer SS, Hopkins LN et al. Carotid stenting with distal protection in high surgical risk patients: the BEACH trial 30 day results. Catheter Cardiovasc Interv 2006;67(4):503-12
10. Safian RD, Bresnahan JF, Jaff MR et al. Protected carotid stenting in high-risk patients with severe carotid artery stenosis. J Am Coll Cardiol 2006;47(12):2384-9
11. Gray WA, Hopkins LN, Yadav S et al. Protected carotid stenting in high-surgical-risk patients: the ARCHeR results. J Vasc Surg 2006;44(2):258-68
12. Gray WA, Yadav JS, Verta P et al. The CAPTURE registry: Results of carotid stenting with embolic protection in the post approval setting. Catheter Cardiovasc Interv 2006;69(3):341-819
13. Reimers B, Sievert H, Schuler GC et al. Proximal endovascular flow blockage for cerebral protection during carotid artery stenting: results from a prospective multicenter registry. J Endovasc Ther 2005;12(2):156-65
14. CaRESS Steering Committee. Carotid Revascularization Using Endarterectomy or Stenting Systems (CaRESS) phase I clinical trial: 1-year results. J Vasc Surg 2005;42(2):213-9
15. Coward LJ, Featherstone RL, Brown MM.  Percutaneous transluminal angioplasty and stenting for carotid artery stenosis. The Cochrane Database of Systematic Reviews 2004, Issue 1. Art. No.: CD000515.pub2. DOI: 10.1002/14651858.CD000515.pub2
16. Sacco RL, Adams R, Albers G et al. Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke: co-sponsored by the Council on Cardiovascular Radiology and Intervention: the American Academy of Neurology affirms the value of this guideline. Stroke 2006;37(2):577-617
17. Chaturvedi S, Bruno A, Feasby T et al. Carotid endarterectomy-an evidence-based review: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2005;65(6):794-801
18. Ederle J, Featherstone RL, Brown MM. Percutaneous transluminal angioplasty and stenting for carotid artery stenosis. Cochrane Database Syst Rev 2007; (4):CD000515
19. Luebke T, Aleksic M, Brunkwall J. Meta-analysis of randomized trials comparing carotid endarterectomy and endovascular treatment. Eur J Vasc Endovasc Surg 2007; 34(4):470-9
20. Ringleb PA, Chatellier G, Hacke W et al. Safety of endovascular treatment of carotid artery stenosis compared with surgical treatment: a meta-analysis. J Vasc Surg 2008; 47(2):350-5
21. Brahmanandam S, Ding EL, Conte MS et al. Clinical results of carotid artery stenting compared with carotid endarterectomy. J Vasc Surg 2008; 47(2):343-9
22. Katzen BT, Criado FJ, Ramee SR et al. Carotid artery stenting with emboli protection surveillance study: thirty-day results of the CASES-PMS study. Catheter Cardiovasc Interv 2007; 70(2):316-23
23. Spes CH, Schwende A, Beier F et al. Short- and long-term outcome after carotid artery stenting with neuroprotection: single-center experience within a prospective registry. Clin Res Cardiol 2007; 96(11):812-21
24. Iyer SS, White CJ, Hopkins LN et al. Carotid artery revascularization in high-surgical-risk patients using the Carotid WALLSTENT and FilterWire EX/EZ: 1-year outcomes in the BEACH Pivotal Group. J Am Coll Cardiol 2008; 51(4):427-34
25. Gurm HS, Yadav JS, Fayad P et al. Long-term results of carotid stenting versus endarterectomy in high-risk patients. N Engl J Med 2008; 358(15):1572-9

Cross References

Percutaneous Venous Transluminal Angioplasty and Stenting, Regence Medical Policy Manual, Surgery, Policy No. 109

Percutaneous Transluminal Angioplasty of Intracranial Atherosclerotic Stenoses With or Without Stenting, Regence Medical Policy Manual, Surgery, No. 141

Surgery Section Table of Contents