Compliance with the provisions in this policy may be monitored and addressed through post payment data analysis and subsequent medical review audits.

Non-invasive tests for cerebrovascular arterial function document the nature, location, extent and severity of disease in extracranial and intracranial vessels, including the carotid and vertebral arteries.

There are numerous tests that measure various aspects of vascular anatomy and physiology as follows:

Direct tests:

• Carotid phonoangiography
• Direct bruit analysis
• Spectral bruit analysis
• Doppler flow velocity
• Ultrasound imaging, including real time, B-scan and Doppler

Indirect tests:

• Periorbital directional Doppler ultrasonography
• Oculoplethysmography and ophthalmodynamometry

Extracranial cerebrovascular testing uses duplex ultrasonography as the primary testing technique. Protocols must encompass both real-time gray scale imaging (B-mode) and analysis of the angle corrected Doppler spectrum.

Duplex Scan

This procedure combines high-resolution B-mode real-time imaging with Doppler ultrasound and spectral analysis. The scan provides anatomic and hemodynamic information regarding the cervical carotid arteries. Data regarding percent stenosis and characterization of atheromatous plaque are provided. Color-flow Doppler is used to enhance conventional data acquisition.

Physiologic Studies

This term implies functional measurement procedures including Doppler ultrasound studies, ocular pneumoplethysmography, blood pressure measurement, transcutaneous oxygen tension measurements and/or plethysmography. A complete study includes pressure measurements and an additional physiologic technique (e.g., Doppler waveforms or plethysmography). Plethysmography implies volume measurement procedures including air, impedance or strain gauge methods.

Transcranial Doppler

Pulsed Doppler ultrasound is used to interrogate the intracranial vasculature of the Circle of Willis. Its value has been established in detecting severe stenoses in the major intracranial arteries, assessing patterns and extent of collateral circulation in patients with known regions of severe stenosis or occlusion, and evaluating and following patients with vasoconstriction particularly after subarachnoid hemorrhage.

Covered Indications

Vascular studies include supervision of the study and interpretation of study results together with hard copy output and analysis of all data (including bidirectional vascular flow or imaging when provided). A hard copy, or a soft copy convertible to a hard copy provides a permanent record of the study performed and must be of a quality that meets accepted radiologic/ultrasonographic standards. These studies also include patient care required to perform the studies.

The following are covered indications for Duplex scans, Doppler Ultrasound with Spectrum Analysis, Ocular Pneumoplethysmography, and Periorbital Doppler (CPT codes 93875, 93880, and 93882):

• Cervical bruits or pulsatile tinnitus
• Pulsatile neck masses
• Amaurosis fugax
• Focal cerebral or ocular transient ischemic attacks (i.e., localizing symptoms, weakness of one side of the face, slurred speech, weakness of a limb, incoordination or limb dysfunction)
• Follow-up of patients with proven carotid disease who are receiving medical therapy
• Follow-up for postoperative patients following carotid endarterectomy
• Hemispheric neurologic symptoms of stroke
• Blunt neck trauma
• Subclavian steal syndrome
• Retinal arterial emboli
• Evaluation of suspected dissection
• Vasculitis of the extracranial carotid arteries
• Cerebral embolization
• Evaluation and follow-up of asymptomatic bruits
• Follow-up of carotid stent placement

The following are covered indications for Transcranial Doppler (TCD) (CPT codes 93886, 93888, 93890, 93892 & 93893):

• Detection of severe stenosis in the major basal intracranial arteries
• Assessment of patterns and extent of collateral circulation in patients with known regions of severe stenosis or occlusion
• Intraoperative and perioperative monitoring of intracranial flow velocity and hemodynamic patterns during carotid endarterectomy
• Evaluation and follow-up of patients with vasoconstriction or spasm resulting from an illness, disease or injury, especially after subarachnoid hemorrhage
• Detection of arteriovenous malformations and study of the supply arteries and flow patterns
• As an adjunct in the assessment of patients with suspected brain death
• Evaluation of invasive therapeutic interventions for cerebral malformations
• Evaluation of cerebral embolization

Coverage Limitations

Any vascular studies performed should be as a result of, or to complement, a thorough patient evaluation and neurological examination.

The use of a simple hand-held or other Doppler device that does not produce hard copy output, or that produces a record that does not permit analysis of bidirectional vascular flow, is considered to be part of the physical examination of the vascular system and is not separately reimbursable. Doppler procedures performed with zero-crossers (i.e., analog [strip chart recorder] analysis) are also included in the office visit.

Non-invasive vascular studies done for screening purposes (i.e., without signs or symptoms of disease) are non-covered by Medicare.

Non-invasive vascular studies are reasonable and necessary only if the outcome will potentially impact the clinical course of the patient. Non-invasive vascular studies will be considered not medically reasonable and necessary if the study results will have no impact on the decision for further diagnostic or therapeutic procedures. For example, if it is obvious from the findings of the history and physical examination that the patient is going to proceed to angiography, then non-invasive vascular studies are not necessary.

The following considerations apply to Duplex scans, Doppler Ultrasound with Spectrum Analysis, Ocular Pneumoplethysmography, and Periorbital Doppler (CPT codes 93875, 93880, and 93882):

• Ocular transient ischemic attacks are defined as visual field deficits and not temporary blurred vision.
• Although episodic dizziness/vertigo may be a symptom of transient ischemic attack, the medical record should document that more common causes of dizziness/vertigo, (e.g., postural hypotension, arrhythmia, decreased cardiac output) were ruled-out prior to evaluation with duplex ultrasonography.
• Headaches, other than basilar, hemiplegic and classical with intractable migraine are not indications for extracranial arterial studies.
• "Drop attacks," or syncope, may be considered reasonable and necessary if there is documented suspicion that the symptoms are associated with vertebrobasilar or bilateral carotid artery disease.
• Extracranial artery studies performed as part of a cardiovascular preoperative workup in the absence of signs or symptoms of disease are screening services and as such are non-covered by Medicare.
• Subclavian ultrasound studies routinely performed in conjunction with carotid ultrasounds in the absence of signs or symptoms of disease are screening services and as such are non-covered by Medicare.

The following indications are considered not medically reasonable and necessary for TCD (CPT codes 93886, 93888, 93890, 93892 and 93893):

• Evaluation of brain tumors
• Assessment of familial and degenerative diseases of the cerebrum, brainstem, cerebellum, basal ganglia and motor neurons
• Evaluation of infectious and inflammatory conditions
• Evaluation of psychiatric disorders
• Epilepsy

The following indications for TCD (procedure codes 93886, 93888, 93890, 93892 and 93893) are considered investigational and will be denied as not medically reasonable and necessary:

• Assessing patients with migraine or headache
• Monitoring during cardiopulmonary bypass and other cerebrovascular and cardiovascular interventions, and other surgical procedures
• Evaluation of patients with dilated vasculopathies such as fusiform aneurysms
• Assessing autoregulation, physiologic, and pharmacological responses of cerebral arteries
• Evaluating children with various vasculopathies such as sickle cell disease, moya moya, and neurofibromatosis

The following methods are not acceptable for reimbursement of CPT codes 93875-93893:

• Thermography
• Mechanical oscillometry
• Inductance plethysmography
• Capitance plethysmography
• Photoelectric plethysmography
• Light reflection rheography
• Pulse Delay Oculoplethysmography
• Carotid Phonoangiography and other forms of bruit analysis are included in the reimbursement for the office visit
• Periorbital Photoplethysmography

Duplex post-interventional follow-up studies are typically limited in scope and unilateral in nature. The "complete" duplex scan codes should seldom be used, while the" unilateral or limited study" codes should be used (except for the patient who had bilateral intervention).

It is usually unnecessary to perform more than one type of physiological study on the same anatomic area. When an uninterpretable study results in performing another type of study, only the successful study should be billed. Code 93875 will rarely be reimbursed.

It would be expected that a service billed with code 93880 would be used as the initial non-invasive diagnostic test. In rare instances where the service billed with code 93880 is not available, the code 93875 service may be performed where it is reasonable and necessary. Otherwise, 93875 should be substituted with 93880, which has a higher accuracy rate.

Physiologic studies and a duplex scan performed on the same day will be considered medically necessary if there is a 50 percent stenosis demonstrated on the duplex scan, or there are significant symptoms present.

The accuracy of noninvasive vascular diagnostic studies depends on the knowledge, skill, and experience of the technologist and physician performing and interpreting the study. Consequently, the physician performing and/or interpreting the study must be capable of demonstrating documented training and experience and maintain any applicable documentation. A vascular diagnostic study may be personally performed by a physician or a technologist.

All non-invasive vascular diagnostic studies performed by a technologist must be performed by, or under the direct supervision of, a technologist who has demonstrated competency by being credentialed in vascular technology, or, such studies must be performed in a facility accredited by the Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL) or the Non-Invasive Vascular Ultrasound Accreditation of the American College of Radiology (ACR). Examples of appropriate certification include the Registered Vascular Technologist (RVT) credential and the Registered Cardiovascular Technologist (RCVT) credential in Vascular Technology. Direct supervision requires the credentialed individual's presence in the facility and immediate availability to the technologist performing the study.

Italicized and/or quoted material is excerpted from the American Medical Association, Current Procedural Terminology (CPT) codes.