CMS Noninvasive Physiologic Studies of Upper or Lower Extremity Arteries Form

Summary Of Evidence

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Analysis of Evidence

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History/Background and/or General Information

Noninvasive peripheral arterial studies include two types of testing, noninvasive physiologic studies and duplex scans. Non-invasive physiologic studies are functional measurement procedures that include Doppler ultrasound studies, blood pressure measurements, transcutaneous oxygen tension measurements, or plethysmography. A complete extremity physiologic study includes pressure measurements and an additional physiologic technique, e.g., Doppler ultrasound study or plethysmography.

Plethysmography implies volume measurement procedures including air impedance or strain gauge methods. Plethysmography involves the measurement and recording (by one of several methods) of changes in the size of a body part as modified by the circulation of blood in that part.

Noninvasive physiologic studies are performed using equipment separate and distinct from the duplex scanner. Duplex scanning combines the information provided by two-dimensional imaging with pulsed-wave doppler techniques which allows analysis of the blood flow velocity.

Vascular studies include patient care required to perform the studies, supervision of the studies and interpretation of study results with copies for patient records of hard copy output with analysis of all data, including bidirectional vascular flow or imaging when provided. The display may be a two-dimensional image with spectral analysis and color flow or a plethysmographic recording that allows for quantitative analysis.

Also, 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 reported (CPT code book 2010, page 471). The appropriate assignment of a specific ultrasound CPT code is not solely determined by the weight, size, or portability of the equipment, but rather by the extent, quality, and documentation of the procedure. If an examination is performed with hand-carried equipment, the quality of the exam, printout, and report must be in keeping with accepted national standards. Doppler procedures performed with zero-crossers (e.g., analog [strip chart recorder] analysis) are also considered to be part of the evaluation and management service and should not be reported separately.

Covered Indications

In general, noninvasive arterial studies are indicated when endovascular or other invasive correction is contemplated, but not to follow noninvasive medical treatment regimens or to monitor unchanged symptomatology. The latter may be followed with physical findings, including Ankle/Brachial Indices (ABIs), and/or progression or relief of signs and/or symptoms.

Noninvasive physiologic studies of the upper or lower extremity arteries performed to establish the level and/or degree of arterial occlusive disease, will be considered medically necessary if a) significant signs and/or symptoms indicate a high likelihood of limb ischemia, and b) the patient is a candidate for invasive therapeutic procedures under any of the following circumstances:

• Claudication of less than one block or of such severity that it interferes significantly with the patient's occupation or lifestyle.
• Rest pain of ischemic origin(typically including the forefoot), associated with absent pulses, which becomes increasingly severe with elevation and diminishes with placement of the leg in a dependent position.
• Tissue loss defined as gangrene or pre-gangrenous changes of the extremity, or ischemic ulceration of the extremity occurring in the absence of pulses.
• Aneurysmal disease of the extremity.
• Evidence of thromboembolic events in an extremity.
• Evidence of compression/occlusion of the vascular structures supplying the upper or lower extremities.
• Blunt or penetrating trauma of the extremities (including complications of diagnostic and/or therapeutic procedures of an extremity).
• Follow-up studies post-operative conditions:
  • In the immediate post-operative period if re-established pulses are lost, become equivocal, or if the patient develops related signs and/or symptoms of ischemia with impending repeat intervention.
  • Following bypass surgery or post-angioplasty with or without stent placement at three months, six months and one year when clinically indicated.
  • Subsequent studies may be allowed if there is clinical evidence of recurrent vascular disease evidenced by signs (i.e. decreased ABI from previous exam) or symptoms (i.e., recurrence of claudication symptoms that interfere significantly with the patient’s occupation or lifestyle). For postoperative surveillance, either a limited Duplex or multi-level Doppler with pressures is usually sufficient, but it is not considered necessary to do both.

Transcutaneous oxygen tension measurements (Tp02) are utilized in conditions for which hyperbaric oxygen therapy (HBO) is being considered, as well as for monitoring the course of HBO therapy. The following conditions are considered medically indicated uses for Tp02 testing prior to, and during the course of HBO therapy:

• Acute traumatic peripheral ischemia
• Crush injuries and suturing of severed limbs
• Progressive necrotizing infections (necrotizing fasciitis)
• Acute peripheral arterial insufficiency
• Preparation and preservation of compromised skin grafts (not for primary management of wounds)
• Soft tissue radionecrosis as an adjunct to conventional treatment
• Tp02 used to determine a line of demarcation between viable and non-viable tissue when surgery or amputation is anticipated

Limitations

A routine history and physical examination, which includes Ankle/Brachial Indices (ABIs), can readily document the presence or absence of ischemic disease in a majority of cases. It is not medically necessary to proceed beyond the physical examination for minor signs and symptoms such as hair loss, absence of a single pulse, relative coolness of a foot, shiny thin skin, or lack of toe nail growth unless related signs and/or symptoms are present which are severe enough to require possible invasive intervention.

An ABI is not a separately reimbursable procedure when performed by itself and would be considered part of the physical examination. When the ABI is abnormal (i.e., <0.9 at rest), it must be accompanied by another appropriate indication before proceeding to more sophisticated or complete studies, except in patients with severely elevated ankle blood pressure.

Examples of additional signs and symptoms that do not indicate medical necessity include:

• Continuous burning of the feet is considered to be a neurologic symptom.
• "Leg pain, nonspecific" or "Pain in limb" as single diagnoses are too general to warrant further investigation unless they can be related to other signs and symptoms.
• Edema rarely occurs with arterial occlusive disease unless it is in the immediate postoperative period, in association with another inflammatory process or in association with rest pain.
• Absence of relatively minor pulses (e.g., dorsalis pedis or posterior tibial) in the absence of ischemic symptoms. The absence of pulses is not an indication to proceed beyond the physical examination unless related signs and/or symptoms are present which are severe enough to require possible invasive intervention.
• Screening of an asymptomatic patient is not covered.

In general, non-invasive studies of the arterial system are to be utilized when invasive correction is contemplated, but not to follow non-invasive medical treatment regimens (e.g., to evaluate pharmacologic intervention) or to monitor unchanged symptomatology. The latter may be followed with physical findings including ABIs and/or progression or relief of signs and/or symptoms.

Noninvasive vascular testing studies are medically necessary only if the outcome will potentially impact the clinical management of the patient. For example, if a patient is (or is not) proceeding on to other diagnostic and/or therapeutic procedures regardless of the outcome of non-invasive studies, and non-invasive vascular procedures will not provide any unique diagnostic information that would impact patient management, then the non-invasive procedures are not medically necessary. 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 medically necessary. It is also expected that the studies are not redundant of other diagnostic procedures that must be performed.

When an uninterpretable study (i.e., poor quality or not in accordance with regulatory standards) results in performing another type of study, only the successful study should be billed. For example, when an uninterpretable non-invasive physiologic study is performed which results in performing a duplex scan, only the duplex scan should be billed.

Noninvasive vascular procedures will not be covered when performed based on internal protocols of the testing facility; a referral for one noninvasive study is not a blanket referral for all studies. Each procedure must be specifically ordered by the physician/nonphysician practitioner treating the patient and the medical necessity criteria specified in this LCD must be met.

Typically, it is appropriate for follow-up studies post-angioplasty, with or without stent placement to be performed at three months, six months and one year. Subsequent studies may be allowed if there is clinical evidence of recurrent vascular disease evidenced by signs (i.e., decreased ABI from previous exam) or symptoms (i.e., recurrence of claudication). For postoperative surveillance, either a limited Duplex or multi-level Doppler with pressures is usually sufficient, but it is not considered necessary to do both.

Performance of both a physiological test and duplex scanning of extremity arteries during the same encounter would not generally be expected. Consequently, documentation must clearly support the medical necessity if both procedures are performed during the same encounter, and be available upon request. Note: Reimbursement of physiologic testing will not be allowed after a duplex scanning has been performed.

Since the signs and symptoms of arterial occlusive disease and venous disease are so divergent, the performance of simultaneous arterial and venous studies during the same encounter should be rare. Consequently, documentation must clearly support the medical necessity of both procedures if performed during the same encounter.

Performance of both non-invasive extracranial arterial studies and non-invasive evaluation of extremity arteries during the same encounter is not appropriate as a general practice or standing protocol, and therefore, would not generally be expected. Consequently, documentation must clearly support the medical necessity if both procedures are performed during the same encounter, and be available upon request.

The medical necessity for performing repeat extremity arterial studies must be clearly documented in the medical record.

Customarily, transcutaneous oxygen tension measurements (TpO2) are acceptable for evaluating healing potential in non-healing or difficult-to-heal wounds at a frequency of no more than twice in any 60-day period.

Generally, it is not expected that these services would be performed more than once a year, excluding inpatient hospital (21) and emergency room (23) places of service.

Note: This LCD imposes utilization guideline limitations. Each patient’s condition and response to treatment must medically warrant the number of services reported for payment. The medical necessity for each service reported to be clearly demonstrated in the patient’s medical record is required. It is expected that patients will not routinely require the maximum allowable number of services.

Please refer to the CMS IOM Publication 100-03, Medicare National Coverage Determinations (NCD) Manual, Chapter 1, Part 1, Section 20.14 Plethysmography for covered and noncovered procedures.

As published in the CMS IOM Publication 100-08, Medicare Program Integrity Manual, Chapter 13, Section 13.5.4, an item or service may be covered by a contractor LCD if it is reasonable and necessary under the Social Security Act Section 1862 (a)(1)(A). Contractors shall determine and describe the circumstances under which the item or service is considered reasonable and necessary.

Provider Qualifications

The accuracy of non-invasive vascular diagnostic studies depends on the knowledge, skill and experience of the technologist and the physician performing the interpretation of the study. Consequently, the technologist and the physician must maintain proof of training and experience.

All non-invasive vascular diagnostic studies must be: (1) performed by a qualified physician, or (2) performed under the general supervision of a qualified physician by a technologist who has demonstrated minimum entry level competency by being credentialed in vascular technology, and/or (3) performed in a laboratory accredited in vascular technology.

Examples of certification in vascular technology for non-physician personnel include:

• Registered Vascular Technologist (RVT) credential
• Registered Vascular Specialist (RVS) credential

These credentials must be provided by nationally recognized credentialing organizations such as:

• The American Registry of Diagnostic Medical Sonographers (ARDMS) which provides RDMS and RVT credentials
• The Cardiovascular Credentialing International (CCI) which provides RVS credential

However, if the facility has a documented process for grand-fathering experienced technicians who have performed the services referenced in this LCD (a process addressing years of service and experience with number of supervised cases), this documentation should be available upon request; otherwise the provider must have documentation available upon request which indicates that the technician meets the credentialing requirements as stated above or is in the process of obtaining this credentialing.

Appropriate nationally recognized laboratory accreditation bodies include:

• Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)
• American College of Radiology (ACR)

Additionally, the transcutaneous oxygen tension measurements (Tp02) may be performed by personnel credentialed as a certified hyperbaric registered nurse (CHRN) or certified hyperbaric technologist (CHT) by the National Board of Diving and Hyperbaric Medical Technology (NBDHMT).

Note: In accordance with 42 CFR 410.33, noninvasive vascular studies performed in an Independent Diagnostic Testing Facility (IDTF) include credentialing requirements that supersede those above.