Endovascular Procedures for Intracranial Arterial Disease (Atherosclerosis and Aneurysms)

POLICY NUMBER

A.2.01.54

DESCRIPTION

Intracranial arterial disease includes thromboembolic events, vascular stenoses, and aneurysms. Endovascular techniques have been investigated for the treatment of intracranial arterial disease. Endovascular therapy is used as an alternative or adjunct to intravenous tissue plasminogen activator and supportive care for acute stenosis and as an adjunct to risk-factor modification for chronic stenosis. For cerebral aneurysms, stent-assisted coiling and the use of flow-diverting stents have been evaluated as an alternative to endovascular coiling in patients whose anatomy is not amenable to simple coiling.

Cerebrovascular Diseases

Cerebrovascular diseases include a range of processes affecting the cerebral vascular system, including arterial thromboembolism, arterial stenosis, and arterial aneurysms, all of which can restrict cerebral blood flow due to ischemia or hemorrhage. Endovascular techniques, including endovascular mechanical embolectomy with various types of devices (ie, stents), and angioplasty with or without stenting have been investigated for the treatment of cerebrovascular diseases.

Acute Stroke

Acute stroke is a leading cause of death in the United States; further, it is a leading cause of adult disability. The risk of stroke among Black patients is nearly double the risk among White patients, and Black patients have a higher risk of death due to stroke than other racial groups. Eighty-seven percent of strokes are ischemic and 13% are hemorrhagic. Differentiation between the two types of stroke is necessary to determine the appropriate treatment. Ischemic stroke occurs when an artery to the brain is blocked by a blood clot, which forms in the artery (thrombotic), or when another substance (ie, plaque, fatty material) travels to an artery in the brain causing a blockage (embolism). Recanalization of the artery, particularly in the first few hours after occlusion, reduces rates of disability and death.

Racial differences in the utilization of endovascular therapy for acute stroke have been reported. Sheriff and colleagues (2022) analyzed the Get With The Guidelines-Stroke database; between 2015 and 2019, Black patients had lower odds of receiving endovascular therapy compared to non-Hispanic Whites (adjusted odds ratio [aOR], 0.83; 95% confidence interval [CI], 0.76 to 0.90). At 3 months, functional independence as assessed by the modified Rankin Scale was less common among Black (aOR, 0.84; 95% CI, 0.75 to 0.95) and Asian (aOR, 0.79; 95% CI, 0.65 to 0.98) individuals compared to non-Hispanic Whites. de Havenon and colleagues (2021) found that Black patients were less likely to receive endovascular therapy compared to White patients (odds ratio [OR], 0.75; 95% CI, 0.70 to 0.81) according to National Inpatient Sample data from 2016 to 2018. Kim and colleagues (2022) conducted a retrospective study of 40,814 acute ischemic strokes that occurred in Texas during 2019 which found that Black patients received endovascular therapy less frequently than White patients (4.1% vs. 5.3%, respectively; adjusted relative risk [aRR], 0.76; 95% CI, 0.66 to 0.88; p<.001) despite similar rates of hospital admission. The rate of receipt of endovascular therapy was similar between White and Hispanic patients.

Intracranial Arterial Stenosis

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% to 12% per year with atherosclerosis of the intracranial anterior circulation and 2.5% to 15% per year with lesions of the posterior (vertebrobasilar) circulation.

Intracranial Aneurysms

Compared with acute ischemic stroke, cerebral aneurysms have a much lower incidence in the United States, with prevalence between 0.5% and 6% of the population. However, they are associated with significant morbidity and mortality due to subarachnoid hemorrhage resulting from aneurysm rupture.

Several devices for endovascular treatment of intracranial arterial disease were cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process or the humanitarian device exemption process. By indication, approved devices are as follows.

Acute Stroke

The table below summarizes the first generation devices with FDA clearance for the endovascular treatment of acute stroke and subsequent approval of stent retrievers.

FDA-Cleared Mechanical Embolectomy Devices for Acute Stroke

FDA: Food and Drug Administration; IV: intravenous; tPA: tissue plasminogen activator.

Intracranial Arterial Stenosis

Two devices were approved by the FDA through the humanitarian device exemption process for atherosclerotic disease. This form of FDA approval is available for devices used to treat conditions with an incident rate of 4,000 or fewer cases per year; the FDA only requires data showing “probable safety and effectiveness.” Devices with their labeled indications are as follows:

1. Neurolink System® (Guidant). "The Neurolink System is indicated for the treatment of patients with recurrent intracranial stroke attributable to atherosclerotic disease refractory to medical therapy in intracranial vessels ranging from 2.5 to 4.5 mm in diameter with ≥50% stenosis and that are accessible to the stent system."

2. Wingspan™ Stent System (Boston Scientific). "The Wingspan Stent System with Gateway PTA [percutaneous transluminal angioplasty] Balloon Catheter is indicated for use in improving cerebral artery lumen diameter in patients with intracranial atherosclerotic disease, refractory to medical therapy, in intracranial vessels with ≥50% stenosis that are accessible to the system."

Intracranial Aneurysms

In 2011, the Pipeline® Embolization Device (Covidien/eV3 Neurovascular), an intracranial aneurysm flow-diverter, was approved by the FDA through the premarket approval process for the endovascular treatment of adults (22 years of age or older) with large or giant wide-necked intracranial aneurysms in the internal carotid artery from the petrous to the superior hypophyseal segments. Approval was based on the Pipeline for Uncoilable for Failed Aneurysms Study, a single-arm, open-label feasibility study that included 108 patients, ages 30 to 75 years, with unruptured large and giant wide-necked aneurysms.

In 2018, Surpass Streamline™ Flow Diverter (Stryker Neurovascular) was approved by the FDA through the premarket approval process (P170024) for use in the endovascular treatment of patients (18 years of age and older) with unruptured large or giant saccular wide-neck (neck width ≥4 mm or dome-to-neck ratio <2) or fusiform intracranial aneurysms in the internal carotid artery from the petrous segment to the terminus arising from a parent vessel with a diameter ≥2.5 mm and ≤5.3 mm. The approval was based on one-year results of the Surpass Intracranial Aneurysm Embolization System Pivotal Trial to Treat Large or Giant Wide Neck Aneurysms (SCENT) study. The SCENT study is continuing follow-up to five years post-procedure as a post-approval study.

The following stents have been approved by the FDA though the humanitarian device exemption process for treatment of intracranial aneurysms:

1. Neuroform™ Microdelivery Stent System (Stryker). In 2002, based on a series of approximately 30 patients with 6-month follow-up, the Neuroform Microdelivery Stent System was approved by the FDA through the humanitarian device exemption process (H020002) for use with embolic coils for the treatment of wide-neck intracranial aneurysms that cannot be treated by surgical clipping.

2. Neuroform™ Atlas Stent System (Stryker) In 2019, the Neuroform Atlas Stent System (Stryker) was approved by the FDA through the premarket approval process (P190031) based on the pivotal ATLAS study including 201 patients with up to 12 months of follow-up. The approved indication is "for use with neurovascular embolization coils in the anterior circulation of the neurovasculature for the endovascular treatment of patients greater than or equal to 18 years of age with saccular wide-necked (neck width greater or equal to 4 mm or a dome-to-neck ratio of <2) intracranial aneurysms arising from a parent vessel with a diameter of greater or equal to 2.0 mm and less than or equal to 4.5 mm." Product Code: QCA.

3. Enterprise™ Vascular Reconstruction Device and Delivery System (Cordis Neurovascular) In 2007, based on a series of approximately 30 patients with 6-month follow-up, the Enterprise Vascular Reconstruction Device and Delivery System was approved by the FDA through the humanitarian device exemption process (H060001) for use with embolic coils for the treatment of wide-neck, intracranial, saccular or fusiform aneurysms.

4. The Low-Profile Visualized Intraluminal Support Device (LVIS™ and LVIS™ Jr.; MicroVention). In 2014, the Low-Profile Visualized Intraluminal Support Device was approved by the FDA through the humanitarian device exemption process (H130005) for use with embolic coils for the treatment of unruptured, wide-neck (neck, ≥4 mm or dome-to-neck ratio, <2), intracranial, saccular aneurysms arising from a parent vessel with a diameter of 2.5 mm or greater and 4.5 mm or smaller. In 2018, the LVIS and LVIS Jr. were approved through the premarket approval process (P170013).

5. PulseRider® Aneurysm Neck Reconstruction Device (Pulsar Vascular, Inc.) In 2017, the PulseRider Aneurysm Neck Reconstruction Device (Pulsar Vascular, Inc.) was approved by the FDA through the humanitarian device exemption process (H160002) for use with neurovascular embolic coils for treatment of unruptured wide-necked intracranial aneurysms with neck width at least 4 mm or dome to neck ratio greater than 2.

POLICY

Intracranial stent placement may be considered medically necessary as part of the endovascular treatment of intracranial aneurysms for individuals when surgical treatment is not appropriate and standard endovascular techniques do not allow for complete isolation of the aneurysm, e.g., wide-neck aneurysm (4 mm or more) or a sack-to-neck ratio less than 2:1.

Intracranial flow-diverting stents with FDA approval for the treatment of intracranial aneurysms may be considered medically necessary as part of the endovascular treatment of intracranial aneurysms that meet anatomic criteria (see Policy Guidelines) and are not amenable to surgical treatment or standard endovascular therapy.

Intracranial stent placement is considered investigational in the treatment of intracranial aneurysms except as noted above.

Intracranial percutaneous transluminal angioplasty with or without stenting is considered investigational in the treatment of atherosclerotic cerebrovascular disease.

The use of endovascular mechanical embolectomy using a device with FDA approval for the treatment of acute ischemic stroke may be considered medically necessary as part of the treatment of acute ischemic stroke for individuals who meet all of the following criteria:

• Have a demonstrated occlusion within the proximal intracranial anterior circulation (intracranial internal carotid artery, or M1 or M2 segments of the middle cerebral artery, or A1 or A2 segments of the anterior cerebral artery); AND

• Can receive endovascular mechanical embolectomy within 12 hours of symptom onset OR within 24 hours of symptom onset if there is evidence of a mismatch between specific clinical and imaging criteria (see Policy Guidelines); AND

• Have evidence of substantial and clinically significant neurologic deficits (see Policy Guidelines section); AND

• Have evidence of salvageable brain tissue in the affected vascular territory (see Policy Guidelines section); AND

• Have no evidence of intracranial hemorrhage or arterial dissection on computed tomography or magnetic resonance imaging.

Endovascular interventions are considered investigational for the treatment of acute ischemic stroke when the above criteria are not met.

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

Selection of Individuals for Endovascular Mechanical Embolectomy for Acute Ischemic Stroke

The major randomized controlled trials (RCTs) demonstrating a benefit with endovascular mechanical embolectomy vary in criteria for selecting individuals based on the presence or absence of salvageable brain tissue. Several RCTs use the Alberta Stroke Program Early Computed Tomography Score, which is a 10-point quantitative computed tomography (CT) score to assess the presence of early ischemic changes. MR CLEAN (Endovascular treatment for acute ischemic stroke in the Netherlands) did not specify imaging criteria to demonstrate salvageable brain tissue. The table below lists the criteria used by other trials.

Trial Selection Criteria for Salvageable Brain Tissue

ASPECTS: Alberta Stroke Program Early Computed Tomography Score; CBF: cerebral blood flow; CBV: cerebral blood volume; CT: computed tomography; CTA: computed tomography angiography; DWI: diffusion-weighted imaging; ESCAPE: Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke; EXTEND-IA: Extending the Time for Thrombolysis in Emergency Neurological Deficits - Intra-Arterial; MCA: middle cerebral artery; MRI: magnetic resonance imaging; REVASCAT: Endovascular Revascularization With Solitaire Device Versus Best Medical Therapy in Anterior Circulation Stroke Within 8 Hours; SWIFT-PRIME: Solitaire With the Intention For Thrombectomy as PRIMary Endovascular Treatment.

The RCTs demonstrating a benefit to endovascular mechanical embolectomy in acute stroke generally had some inclusion criteria to reflect stroke severity, with the exception of the EXTEND-IA (Extending the Time for Thrombolysis in Emergency Neurological Deficits - Intra-Arterial) trial. The REVASCAT (Endovascular Revascularization With Solitaire Device Versus Best Medical Therapy in Anterior Circulation Stroke Within 8 Hours) and ESCAPE (Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke) trials both required a baseline (poststroke) National Institutes of Health Stroke Scale (NIHSS) score of 6 or higher. MR CLEAN specified a clinical diagnosis of acute stroke with a deficit on the NIHSS score of 2 points or more. SWIFT-PRIME (Solitaire With the Intention For Thrombectomy as PRIMary Endovascular Treatment) specified a NIHSS score of 8 or more and less than 30 at the time of randomization.

The DAWN (Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) and DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) studies enrolled individuals from 6 up to 24 hours of the time last time known to be well if there was evidence of a mismatch between specific clinical and imaging criteria (infarct size and volume was assessed with the use of diffusion-weighted magnetic resonance imaging or perfusion CT) (see the table below).

Trial Selection Criteria for Individuals 6 to 25 Hours Post Infarct

DAWN: Clinical Mismatch in the Triage of Wake Up and Late Presenting Strokes Undergoing Neurointervention With Trevo; DEFUSE 3: Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3; NIHSS: National Institutes of Health Stroke Scale.

Other Policy Guidelines

Flow-diverting stents are indicated for the treatment of large or giant wide-necked intracranial aneurysms, with a size of 10 mm or more and a neck diameter of 4 mm or more, in the internal carotid artery from the petrous to the superior hypophyseal segments.

This policy only addresses endovascular therapies used on intracranial vessels.

These policy statements are not intended to address the use of rescue endovascular therapies, including intra-arterial vasodilator infusion and intracranial percutaneous transluminal angiography, in delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

Medically Necessary is defined as those services, treatments, procedures, equipment, drugs, devices, items or supplies furnished by a covered Provider that are required to identify or treat a Member's illness, injury or Mental Health Disorders, and which Company determines are covered under this Benefit Plan based on the criteria as follows in A through D:

A.  consistent with the symptoms or diagnosis and treatment of the Member's condition, illness, or injury; and

B.  appropriate with regard to standards of good medical practice; and

C.  not solely for the convenience of the Member, his or her Provider; and

D.  the most appropriate supply or level of care which can safely be provided to Member. When applied to the care of an Inpatient, it further means that services for the Member's medical symptoms or conditions require that the services cannot be safely provided to the Member as an Outpatient.

For the definition of medical necessity, “standards of good medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. BCBSMS makes no payment for services, treatments, procedures, equipment, drugs, devices, items or supplies which are not documented to be Medically Necessary. The fact that a Physician or other Provider has prescribed, ordered, recommended, or approved a service or supply does not in itself, make it Medically Necessary.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

7/2003: Approved by Medical Policy Advisory Committee (MPAC).

11/11/2005: Code Reference section updated, CPT codes 35475, 36100, 36215-36218 added, 37799 deleted; ICD9 procedure codes 00.40-00.43 added.

3/10/2006: Coding updated. CPT4/HCPCS 2006 revisions added to policy.

3/10/2006: Policy reviewed, no changes.

5/24/2006: Coding update. 36100, 36215-36218 deleted.

9/22/2006: Coding updated. ICD9 2006 revisions added to policy.

5/10/2007: Policy reviewed, description section updated.

8/19/2009: Policy reviewed, no changes.

8/18/2010: Policy reviewed. Removed CPT code 35475 from the Non-Covered Codes Table based on the policy statement.

08/11/2011: Policy titled changed from "Percutaneous Transluminal Angioplasty of Intracranial Atherosclerotic Stenoses With or Without Stenting" to "Endovascular Procedures (Angioplasty and/or Stenting) for Intracranial Arterial Disease (Atherosclerosis and Aneurysms)" to reflect the wider scope of the policy. Policy description updated. Added a new policy statement to indicate that the use of stents may be considered medically necessary for treatment of selected patients with intracranial aneurysms. Use is generally reserved for cases where successful occlusion of the aneurysm cannot be obtained with standard endovascular techniques, e.g., wide-neck aneurysms. FEP verbiage added to the Policy Exceptions section. Added a Covered Codes table and moved the following codes from non-covered to covered: 61630, 61635, 00.40, 00.41, 00.42, 00.43, 00.44. Added the following codes to the Code Reference section: 00.45, 00.46, 00.47, 00.48, 00.62, 00.65, 430, 431, 437.3 and 747.81. Deleted 39.50 from the Code Reference section. Deleted the Non-Covered codes table.

06/06/2012: Policy reviewed; no changes.

08/09/2013: Policy reviewed; no changes.

04/22/2014: Policy reviewed; description updated regarding endovascular treatments and available devices with an indication for acute stroke. Added investigational policy statement that "Endovascular interventions (mechanical embolectomy, angioplasty, stenting) are considered investigational in the treatment of acute stroke."

10/30/2014: Added new policy statement that intracranial flow diverting stents with FDA approval for the treatment of intracranial aneurysms may be considered medically necessary as part of the endovascular treatment of intracranial aneurysms that meet anatomic criteria (see “Policy Guidelines”) and are not amenable to surgical treatment or standard endovascular therapy. Policy guidelines updated regarding flow-diverting stents.

02/12/2015: Policy title changed from "Endovascular Procedures (Angioplasty and/or Stenting) for Intracranial Arterial Disease (Atherosclerosis and Aneurysms)" to "Endovascular Procedures for Intracranial Arterial Disease (Atherosclerosis and Aneurysms)." Policy description updated regarding endovascular therapy in the treatment of acute stroke. Updated FDA-approved stents for treatment of intracranial aneurysms. Policy statement unchanged. Policy guidelines updated to add the following statement: These policy statements are not intended to address the use of rescue endovascular therapies, including intra-arterial vasodilator infusion and intracranial percutaneous transluminal angiography, in the setting of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

08/27/2015: Code Reference section updated for ICD-10. Removed ICD-9 procedure codes 00.40, 00.41, 00.42, 00.43, 00.44, 00.45, 00.46, 00.47, and 00.48.

06/09/2016: Policy number A.2.01.54 added. Policy Guidelines updated to add medically necessary and investigative definitions.

09/30/2016: Code Reference section updated to add the following new ICD-10 procedure codes: 037G346, 037G356, 037G35Z, 037G366, 037G36Z, 037G376, 037G37Z, 037G3D6, 037G3E6, 037G3EZ, 037G3F6, 037G3FZ, 037G3G6, 037G3GZ, 037G3Z6, 037G446, 037G456, 037G45Z, 037G466, 037G46Z, 037G476, and 037G47Z.

09/15/2017: Policy description updated regarding acute stroke and devices. Added policy statement that endovascular mechanical embolectomy for acute ischemic stroke may be considered medically necessary for patients meeting certain criteria. Investigational statement revised to state that endovascular interventions are considered investigational in the treatment of acute ischemic stroke when the above criteria are not met. It previously stated: Endovascular interventions (mechanical embolectomy, angioplasty, stenting) are considered investigational in the treatment of acute stroke. Policy guidelines updated regarding patient selection for endovascular mechanical embolectomy for acute ischemic stroke. Code Reference section updated to add CPT code 61645, ICD-10 procedure codes 03CG3ZZ, 03CG4ZZ, 03CG3Z6, and 03CG4Z6, and ICD-10 diagnosis codes I63.031 - I63.09, I63.131 - I63.139, I63.231 - I63.239, I63.311 - I63.319, I63.321 - I63.329, I63.411 - I63.419, I63.421 - I63.429, I63.521 - I63.529, and I65.21 - I65.29.

12/01/2017: Policy description updated. Policy statements unchanged.

04/27/2018: Policy description updated regarding devices. Medically necessary criteria updated to extend the timeframe for patients receiving endovascular mechanical embolectomy to up to 24 hours after symptom onset for select patients. Policy Guidelines updated regarding patient selection criteria.

09/28/2018: Code Reference section updated to add new ICD-10 procedure code 03CG3Z7, effective 10/01/2018.

05/07/2019: Policy description updated regarding devices. Policy statements unchanged.

09/30/2019: Code Reference section updated regarding deleted ICD-10 procedure codes.

05/15/2020: Policy description updated regarding stents. Policy statements unchanged. Policy Guidelines updated regarding trials.

06/11/2021: Policy description updated regarding acute stroke. Policy statements unchanged. Policy Guidelines updated regarding randomized controlled trials and to change "Nervous/Mental Conditions" to "Mental Health Disorders" and "Medically Necessary" to "medical necessity." Code Reference section updated to remove deleted ICD-10 procedure codes 03CG3Z6, 03CG4Z6, 037G346, 037G356, 037G366, 037G376, 037G3D6, 037G3E6, 037G3F6, 037G3G6, 037G3Z6, 037G446, 037G456, 037G466, and 037G476.

05/23/2022: Policy description updated regarding acute stroke and devices for acute stroke. Policy statements unchanged.

05/08/2023: Policy description updated regarding devices. Policy statements updated to change "patients" to "individuals." Policy Guidelines updated with minor changes.

05/07/2024: Policy reviewed. Policy statements unchanged. Policy Guidelines updated to change "patients" to "individuals" and to update table information.

05/06/2025: Policy description updated. Policy statements unchanged.

SOURCE(S)

Blue Cross Blue Shield Association policy # 2.01.54

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy.

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.

Covered Codes

CPT copyright American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association.