Angioplasty and/or Stenting for Intracranial Arterial Disease
DESCRIPTION
It is estimated that intracranial atherosclerosis causes about 8% of all ischemic strokes. Intracranial stenosis may contribute to stroke in two ways: either due to embolism or low flow ischemia in the absence of collateral circulation. Recurrent annual stroke rates are estimated at 4–12% per year with atherosclerosis of the intracranial anterior circulation and 2.5–15% per year with lesions of the posterior (vertebrobasilar) circulation. Medical treatment typically includes either anticoagulant therapy (i.e., warfarin) or antiplatelet therapy (e.g., aspirin). The “Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial was a randomized trial that compared the incidence of stroke brain hemorrhage or death among individuals randomized to receive either aspirin or warfarin. The trial found that over a mean 1.8 years of follow-up, warfarin provided no benefit over aspirin and was associated with a significantly higher rate of complications. In addition, if symptoms could be attributed to low flow ischemia, agents to increase mean arterial blood pressure and avoidance of orthostatic hypotension may be recommended. However, medical therapy has been considered less than optimal. For example, in individuals with persistent symptoms despite antithrombotic therapy, the subsequent rate of stroke or death has been extremely high, estimated in one study at 45%, with recurrent events occurring within 1 month of the initial recurrence. Surgical approaches have met with limited success. The widely quoted extracranial-intracranial (EC/IC) bypass study randomized 1,377 patients with symptomatic atherosclerosis of the internal carotid or middle cerebral arteries to medical care or EC/IC bypass. The outcomes in the two groups were similar, suggesting that the EC/IC bypass is ineffective in preventing cerebral ischemia. Due to inaccessibility, surgical options for the posterior circulation are even more limited.
Percutaneous transluminal angioplasty (PTA) involves inserting a balloon catheter into a narrow or occluded vessel to recanalize and dilate the vessel by inflating the balloon. PTA has been approached cautiously for use in the intracranial circulation, due to technical difficulties in catheter and stent design and the risk of embolism, which may result in devastating complications if occurring in the posterior fossa or brain stem. Devices utilized for intracranial atherosclerotic cerebrovascular disease are the Neurolink System ® and the Wingspan™ Stent System.
Intracranial stents are also being used in the treatment of cerebral aneurysms. Stent-assisted coiling began as an approach to treat fusiform or wide-neck aneurysms in which other surgical or endovascular treatment strategies may not be feasible. As experience grew, stenting was also used in smaller berry aneurysms as an approach to decrease the rate of retreatment needed in individuals who receive coiling. A randomized trial has demonstrated that treatment of ruptured intracranial aneurysms with coiling leads to improved short-term outcome compared to surgical clipping; however, individuals who receive coiling have a need for more repeat/follow-up procedures. Two stents have received FDA approval through the humanitarian device exemption (HDE) program for treatment of intracranial aneurysms. They are the Neurofoam™ Microdelivery Stent System and the Enterprise® Vascular Reconstruction Device and Delivery System.
POLICY
Intracranial stent placement as part of the endovascular treatment of intracranial aneurysms is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
Intracranial stent placement in the treatment of intracranial aneurysms, except as noted above, is considered investigational.
Intracranial percutaneous transluminal angioplasty with or without stenting in the treatment of atherosclerotic cerebrovascular disease is considered investigational.
Any device utilized for this procedure must have FDA approval specific to the indication, otherwise it will be considered investigational.
Policies with similar titles: Percutaneous Transluminal Angioplasty of the Aortic Arch Vessels with or without stenting (Brachiocephalic, Carotid, Subclavian & Vertebral Arteries) and of Coarctation of the Aorta
MEDICAL APPROPRIATENESS
Intracranial stent placement as part of the endovascular treatment of intracranial aneurysms is considered medically appropriate if ALL of the following criteria are met:
Surgical treatment is not appropriate
Standard endovascular techniques do not allow for complete isolation of the aneurysm (e.g., wide-neck aneurysm [4 mm or more] or sack-to-neck ratio less than 2:1)
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
Substantive trial data comparing angioplasty with or without stenting to best medical therapy in the treatment of atherosclerotic cerebrovascular disease is lacking. Therefore, whether there is a net clinical benefit with angioplasty and/or stenting similar to, or better than, medical therapy is lacking for the treatment of symptomatic intracranial stenosis. Data regarding intracranial stent placement in the treatment of intracranial aneurysms for conditions other than those indicated in the policy above is also lacking. Therefore, the net clinical benefit is not known.
SOURCES
Biondi, A, Janardhan, V., Katz, J. M., Salvaggio, K., Riina, H. A., & Gobin, Y. P. (2007). Neuroform stent-assisted coil embolization of wide-neck intracranial aneurysms: Strategies in stent deployment and midterm follow-up. Neurosurgery, 61 (3), 460-468. Abstract retrieved April 18, 2011 from PubMed database.
BlueCross BlueShield Association. Medical Policy Reference Manual. (2:2011). Endovascular procedures (angioplasty and/or stenting) for intracranial arterial disease (atherosclerosis and aneurysms) (2.01.54). Retrieved April 13, 2011 from BlueWeb. (24 articles and/or guidelines reviewed)
Complete Guide to Medicare Coverage Issues [Computer software]. (2011, April). Percutaneous transluminal angioplasty (PTA) (NCD 20.7, p. 2-7 - 2-11). The Ingenix Complete Guide to Medicare Coverage Issues.
Higashida, R. T., Meyers, P. M., Connors, J. J. III, Sacks, D., Strother, C. M., Barr, J., et al. (2005, October). Intracranial angioplasty & stenting for cerebral atherosclerosis: A position statement of the American Society of Interventional and Therapeutic Neuroradiology, Society of Interventional Radiology, and the American Society of Neuroradiology. Journal of Vascular and Interventional Radiology, 16 (10), 1281 - 1285.
Meyers, P., Schumacher, H., Higashida, R., Bamwell, S., Creager, M., Gupta, R., et al. (2009). Indications for the performance of intracranial endovascular neuron-interventional procedures: a scientific statement from the American Heart Association Council on Cardiovascular Radiology and Intervention, Stroke Council, Council on Cardiovascular Surgery and Anesthesia, Interdisciplinary Council on Peripheral Vascular Disease, and Interdisciplinary Council on Quality of Care and Outcomes Research. Circulation, 119 (16), 2235 - 2249.
Mocco, J., Snyder, K. V., Albuquerque, F. C., Bendok, B. R., Alan, S. B., Carpenter, J. S. et al. (2009). Treatment of intracranial aneurysms with the Enterprise stent: A multicenter registry. Journal of Neurosurgery, 110 (1), 35-39. Abstract retrieved April 18, 2011 from PubMed database.
National Institute for Health and Clinical Excellence. (2007, October). Endovascular stent insertion for intracranial atherosclerotic disease. Retrieved March 3, 2010 from: http://www.nice.org.uk/nicemedia/pdf/IPG233Guidance.pdf.
U. S. Food and Drug Administration. (2002, August). Center for Devices and Radiological Health. NEUROLINK® System - H010004. Retrieved January 15, 2008 from http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=H010004.
U. S. Food and Drug Administration. (2005, August). Center for Devices and Radiological Health. Wingspan stent system with Gateway PTA balloon catheter - H050001. Retrieved March 02, 2010 from http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=H050001.
Wajnberg, E., de Souza, J. M., Marchiori, E., & Gasparetto, E. L. (2009). Single-center experience with the Neuroform stent for endovascular treatment of wide-necked intracranial aneurysms. Surgical Neurology, 72(6), 612-9. Abstract retrieved April 18, 2011 from PubMed database.
ORIGINAL EFFECTIVE DATE: 8/12/2006
MOST RECENT REVIEW DATE: 9/11/2011
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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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