General Information
It is an expectation that all patients receive care/services from a licensed clinician. All appropriate supporting documentation, including recent pertinent office visit notes, laboratory data, and results of any special testing must be provided. If applicable: All prior relevant imaging results and the reason that alternative imaging cannot be performed must be included in the documentation submitted.

Where a specific clinical indication is not directly addressed in this guideline, medical necessity determination will be made based on widely accepted standard of care criteria. These criteria are supported by evidence-based or peer-reviewed sources such as medical literature, societal guidelines and state/national recommendations.

Purpose
CTA/CTV
Computed tomography angiography (CTA) generates images of the arteries that can be evaluated for evidence of stenosis, occlusion, or aneurysms. It is used to evaluate the
arteries of the abdominal aorta and the renal arteries. CTA uses ionizing radiation and requires the administration of iodinated contrast agent, which is a potential hazard in patients with impaired renal function. Lower Extremity CTA is not used as a screening tool, e.g., evaluation of asymptomatic patients without a previous diagnosis.

NOTE: Authorization for MR Angiography covers both arterial and venous imaging. The term angiography refers to both arteriography and venography.

Special Note
Imaging Request
When a separate CTA and CT exam is requested, documentation requires a medical reason that clearly indicates why additional CT imaging of the lower extremity is needed. 

Policy
INDICATIONS
Peripheral Vascular Disease

NOTE: When aortograms CTA (CT Angiography) (CPT Code 75635) has not been recently approved, when aortoiliac disease is not a concern, or the state of the aorta
and iliac arteries is already known.

For evaluation of known or suspected lower extremity arterial disease:

• For known or suspected peripheral arterial disease (such as claudication, or clinical concern for vascular causes of ulcers) when non-invasive studies (pulse volume recording, ankle-brachial index, toe brachial index, segmental pressures, or doppler ultrasound) are abnormal or indeterminate OR
• For critical limb ischemia with ANY of the below clinical signs of peripheral artery disease (prior ultrasound is not needed; if done and negative, CTA should still be approved)^1,2
  • Ischemic rest pain
  • Tissue loss
  • Gangrene
• After stenting or surgery with signs of recurrent symptoms, abnormal ankle/brachial index, abnormal or indeterminate arterial Doppler, or abnormal or indeterminate pulse volume recording³

NOTE: When vascular imaging of the aorta and both legs, i.e., CTA aortogram and runoff is desired (sometimes incorrectly requested as Abd/Pelvis CTA & Lower Extremity CTA
Runoff), only one authorization request is required, using CPT Code 75635 CTA Aortogram. This study provides for imaging of the abdomen, pelvis, and both legs. A separate
authorization for Lower Extremity CTA is NOT needed. If ONLY the Extremity CTA is requested and Abdominal imaging is not needed, Lower Extremity CTA can be issued.

Popliteal Artery Entrapment Syndrome
After abnormal arterial ultrasound and when imaging will change management⁴

Deep Venous Thrombosis
Clinical suspicion of lower extremity DVT (when ultrasound is abnormal or inconclusive and a positive study would change management)^5,6,7

Clinical Suspicion of Vascular Disease
With abnormal or indeterminate ultrasound or other imaging

• Trauma⁸
• Vasculitis^9,10
• Aneurysm⁹
• Stenosis/occlusions¹⁰

Hemodialysis Graft Dysfunction
After Doppler ultrasound, if findings were not adequate for treatment decisions¹¹

Vascular Malformation^12,13

• After initial evaluation with ultrasound if:
  • Results will change management
  • Results are inconclusive on ultrasound
  • If a known or suspected high flow lesion
• A concurrent CT is also approvable for initial evaluation and/or preoperative planning if MRI is contraindicated or cannot be performed or surgeon preference.

Traumatic Injuries
Clinical findings suggestive of arterial injury⁸

Pre-operative/Procedure Evaluation
Pre-operative evaluation for a planned surgery or procedure¹⁴

Post-operative/Procedure Evaluation
A follow-up study may be needed to help evaluate a patient’s progress after treatment, procedure, intervention, or surgery. Documentation requires a medical reason that clearly indicates why additional imaging is needed for the type and area(s) requested.^15,16

Evaluation of Tumor
When needed for clarification of vascular invasion from tumor after prior imaging (may be approved in combination with CT or MRI of tumor).

Genetic Syndromes and Rare Diseases

• Known vascular EDS (vEDS) with acute extremity pain and concern for dissection/rupture^17,18
• Vascular EDS (vEDS) surveillance imaging: with inconclusive ultrasound or ultrasound suggestive of vascular pathology^17,18
• Known Williams Syndrome: when there is concern for vascular disease based on abnormal exam or imaging findings (such as diminished pulses, bruits or signs of diffuse thoracic aortic stenosis¹⁹
• For other syndromes and rare diseases not otherwise addressed in the guideline, coverage is based on a case-by-case basis using societal guidance.

Further Evaluation of Indeterminate Findings on Prior Imaging
Unless follow-up is otherwise specified within the guideline:

• For initial evaluation of an inconclusive finding on a prior imaging report (i.e., X-ray, ultrasound or CT) that requires further clarification.
• One follow-up exam of a prior indeterminate MR/CT finding to ensure no suspicious interval change has occurred. (No further surveillance unless specified as highly suspicious or change was found on last follow-up exam.)

Rationale
Contraindications and Preferred Studies

• Contraindications and reasons why a CT/CTA cannot be performed may include: impaired renal function, significant allergy to IV contrast, pregnancy (depending on trimester).
• Contraindications and reasons why an MRI/MRA cannot be performed may include: impaired renal function, claustrophobia, non-MRI compatible devices (such as noncompatible defibrillator or pacemaker), metallic fragments in a high-risk location, patient exceeds weight limit/dimensions of MRI machine.

CTA and Screening: Peripheral Vascular Disease
The USPSTF (U.S. Preventive Services Task Force) does not recommend routine screening for peripheral vascular disease in asymptomatic patients.²⁰ High-risk patients (e.g., diabetics) may be screened with ABI (ankle brachial index) and duplex ultrasound. The ankle- brachial index (ABI) is the ratio of systolic blood pressure at the ankle divided by the systolic pressure of the upper arm. The normal range lies between 0.9 – 1.4. An ABI²¹ of less than 0.9 is a reliable indicator of the presence of lower extremity PAD, indicating atheroocclusive arterial disease. The upper limit of normal ABI should not exceed 1.40. An ABI > 1.40 is suggestive of arterial stiffening (i.e., medial arterial calcification) and is also associated with a higher risk of cardiovascular events and is seen in elderly patients, typically in those with diabetes or chronic kidney disease (CKD).

References  

1. Browne W F, Sung J, Majdalany B S, Khaja M S, Calligaro K et al. ACR Appropriateness Criteria® Sudden Onset of Cold, Painful Leg: 2023 Update. Journal of the American College of Radiology. 2023; 20: S565 - S573. 10.1016/j.jacr.2023.08.012.
2. Shishehbor M, White C, Gray B, Menard M, Lookstein R et al. Critical Limb Ischemia: An Expert Statement. J Am Coll Cardiol. Nov 1, 2016; 68: 2002-2015. 10.1016/j.jacc.2016.04.071.
3. Pollak A, Norton P, Kramer C. Multimodality imaging of lower extremity peripheral arterial disease: current role and future directions. Circ Cardiovasc Imaging. Nov 2012; 5: 797-807. 10.1161/circimaging.111.970814.
4. Bradshaw S, Habibollahi P, Soni J, Kolber M, Pillai A. Popliteal artery entrapment syndrome. Cardiovascular diagnosis and therapy. 2021; 11: 1159-1167.
5. American College of Radiology. ACR Appropriateness Criteria® Suspected Lower Extremity Deep Vein Thrombosis. American College of Radiology. 2018; 2023:
6. Karande G, Hedgire S, Sanchez Y, Baliyan V, Mishra V et al. Advanced imaging in acute and chronic deep vein thrombosis. Cardiovasc Diagn Ther. Dec 2016; 6: 493-507.
7. 10.21037/cdt.2016.12.06.
8. Katz D S, Fruauff K, Kranz A, Hon M. Imaging of deep venous thrombosis: A multimodality overview. Applied Radiology. Updated March 5, 2014; Accessed January 23, 2023:
9. Wani M, Ahangar A, Ganie F, Wani S, Wani N. Vascular injuries: trends in management. Trauma Mon. Summer 2012; 17: 266-9. 10.5812/traumamon.6238.
10. Seitz L, Seitz P, Pop R, Lötscher F. Spectrum of Large and Medium Vessel Vasculitis in Adults: Primary Vasculitides, Arthritides, Connective Tissue, and Fibroinflammatory Diseases. Current Rheumatology Reports. 2022; 24: 352 - 370. 10.1007/s11926-022-01086-2.
11. Conte M, Pomposelli F, Clair D, Geraghty P, McKinsey J et al. Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: Management of asymptomatic disease and claudication. Journal of Vascular Surgery. 2015; 61: 2S - 41S.e1. 10.1016/j.jvs.2014.12.009.
12. Richarz S, Isaak A, Aschwanden M, Partovi S, Staub D. Pre-procedure imaging planning for dialysis access in patients with end-stage renal disease using ultrasound and upper extremity computed tomography angiography: a narrative review. Cardiovascular Diagnosis and Therapy. 2022; 13: 122-132.
13. Madani H, Farrant J, Chhaya N, Anwar I, Marmery H et al. Peripheral limb vascular malformations: an update of appropriate imaging and treatment options of a challenging condition. Br J Radiol. Mar 2015; 88: 20140406. 10.1259/bjr.20140406.
14. Obara P, McCool J, Kalva S P, Majdalany B S, Collins J D et al. ACR Appropriateness Criteria® Clinically Suspected Vascular Malformation of the Extremities. J Am Coll Radiol. 2019; 16: S340-s347. 10.1016/j.jacr.2019.05.013.
15. Azene E M, Steigner M L, Aghayev A, Ahmad S, Clough R E et al. ACR Appropriateness Criteria® Lower Extremity Arterial Claudication-Imaging Assessment for Revascularization: 2022 Update. Journal of the American College of Radiology. 2022; 19: S364 - S373. 10.1016/j.jacr.2022.09.002.
16. Conte M S, Bradbury A W, Kolh P, White J V, Dick F et al. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg. 2019; 69: 3S-125S.e40. 10.1016/j.jvs.2019.02.016.
17. Cooper K, Majdalany B S, Kalva S P, Chandra A, Collins J D et al. ACR Appropriateness Criteria® Lower Extremity Arterial Revascularization-Post-Therapy Imaging. J Am Coll Radiol. 2018;15: S104-s115. 10.1016/j.jacr.2018.03.011.
18. Beyers P. Vascular Ehlers-Danlos Syndrome. GeneReviews [Internet]. 2019;18. Bowen J, Hernandez M, Johnson D, Green C, Kammin T et al. Diagnosis and management of vascular Ehlers-Danlos syndrome: Experience of the UK national diagnostic service, Sheffield. European Journal of Human Genetics. 2023; 31: 749 - 760. 10.1038/s41431-023-01343-7.
19. Morris C. Williams Syndrome. [Updated 2023 Apr 13]. GeneReviews® [Internet]. 2023; 
20. US Preventive Services Task Force. Screening for Peripheral Artery Disease and Cardiovascular Disease Risk Assessment with the Ankle-Brachial Index: US Preventive Services Task Force Recommendation Statement. JAMA. 2018; 320: 177 - 183. 10.1001/jama.2018.8357.
21. Golledge J, Moxon J, Rowbotham S, Pinchbeck J, Quigley F. High ankle brachial index predicts high risk of cardiovascular events amongst people with peripheral artery disease. PLOS ONE. 2020; 15: true.

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

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