Description
Lower extremity computed tomography angiography (CTA) is an effective, noninvasive and robust imaging modality that is used in the assessment of symptomatic lower extremity vascular disease. It has excellent spatial resolution and shows accurate details of peripheral vasculature. CTA is an effective alternative to catheter-based angiography and allows accurate planning of open surgical and endovascular interventions.

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.

OVERVIEW:
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 ABI^21,22 of less than 0.9 is a reliable indicator of the presence of lower extremity PAD, indicating athero- occlusive 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).
 
CTA and screening for peripheral vascular disease: The USPSTF (U.S. Preventive Services Task Force) does not recommend routine screening for peripheral vascular disease in asymptomatic patients.²³ High risk patients 

Policy
LOWER EXTREMITY CTA is considered MEDICALLY NECESSARY for the following indications:

INDICATIONS FOR LOWER EXTREMITY CTA/CTV (COMPUTED TOMOGRAPHY ANGIOGRAM/COMPUTED TOMOGRAPHY VENOGRAM)

Abdominal Arteries CTA (CT Angiography) (CPT Code 75635) includes run-off, so this is not approvable when done in conjunction with that exam.

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

Peripheral Vascular Disease when Abdominal Arteries CTA (CT Angiography) (CPT Code 75635) has not been recently approved or when aortoiliac disease is not a concern or the state of the aorta and iliac arteries is already known.

• Critical Limb ischemia ANY of the below with clinical signs of peripheral artery disease. Ultrasound imaging is not needed. If done and negative, it should still be approved due to high false negative rate^1,2
  • Ischemic rest pain
  • Tissue loss
  • Gangrene
• Claudication with abnormal or indeterminate ankle/brachial index, pulse volume recording or arterial Doppler^3-5
• Clinical concern for vascular cause of ulcers with abnormal or indeterminate ultrasound (ankle/brachial index, arterial Doppler)⁶
• After stenting or surgery with signs of recurrent symptoms OR abnormal ankle/brachial index; abnormal or indeterminate arterial Doppler, OR pulse volume recording)5

Popliteal Artery Entrapment Syndrome with abnormal arterial ultrasound⁷

Deep Venous Thrombosis with clinical suspicion of lower extremity DVT after abnormal or non- diagnostic ultrasound where a positive study would change management^8-10

Clinical suspicion of vascular disease with abnormal or indeterminate ultrasound or other imaging

• Tumor invasion¹¹
• Trauma¹²
• Vasculitis¹³
• Aneurysm¹⁴
• Stenosis/occlusions¹⁵

Hemodialysis Graft Dysfunction after Doppler ultrasound not adequate for treatment decisions¹⁶

Vascular Malformation^17,18

• After initial evaluation with ultrasound and results will change management OR
• Inconclusive ultrasound OR
• If a known or suspected high flow lesion
• For preoperative planning (CT is also approvable for initial evaluation if MRI contraindicated)

(MRA preferred however CTA useful in delineating some high flow lesions such as an arteriovenous malformation.)

Traumatic injuries with clinical findings suggestive of arterial injury¹²

Assessment/evaluation of known vascular disease/condition

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.)

Pre-operative/procedural evaluation

• Pre-operative evaluation for a planned surgery or procedure³

Post- operative/procedural 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^19,20

Special Circumstances²

• High suspicion of an acute arterial obstruction - Arteriography preferred (the gold standard).
• Renal impairment
  • Not on dialysis
    • Mild to moderate, GFR 30 – 89 ml/min MRA can be done
    • Severe, GFR < 30 ml/min MRA without contrast
  • On dialysis
    • CTA with contrast can be done
• Doppler ultrasound can be useful in evaluating bypass grafts
   

All other uses of this technology are investigational and/or unproven and therefore considered NOT MEDICALLY NECESSARY.

References  

1. Shishehbor MH, White CJ, Gray BH, et al. Critical Limb Ischemia: An Expert Statement. J Am Coll Cardiol. Nov 1 2016;68(18):2002-2015. doi:10.1016/j.jacc.2016.04.071
2. Weiss CR, Azene EM, Majdalany BS, et al. ACR Appropriateness Criteria(®) Sudden Onset of Cold, Painful Leg. J Am Coll Radiol. May 2017;14(5s):S307-s313. doi:10.1016/j.jacr.2017.02.015
3. Ahmed O, Hanley M, Bennett SJ, et al. ACR Appropriateness Criteria(®) Vascular Claudication-Assessment for Revascularization. J Am Coll Radiol. May 2017;14(5s):S372-s379. doi:10.1016/j.jacr.2017.02.037
4. Pollak AW, Kramer CM. MRI in Lower Extremity Peripheral Arterial Disease: Recent Advancements. Curr Cardiovasc Imaging Rep. Feb 1 2013;6(1):55-60. doi:10.1007/s12410-012- 9175-z
5. Pollak AW, Norton PT, Kramer CM. Multimodality imaging of lower extremity peripheral arterial disease: current role and future directions. Circ Cardiovasc Imaging. Nov 2012;5(6):797- 807. doi:10.1161/circimaging.111.970814
6. Rosyid FN. Etiology, pathophysiology, diagnosis and management of diabetics’ foot ulcer. Int J Res Med Sci. 2017;5(10):4206-13. doi:http://dx.doi.org/10.18203/2320-6012.ijrms20174548
7. Williams C, Kennedy D, Bastian-Jordan M, Hislop M, Cramp B, Dhupelia S. A new diagnostic approach to popliteal artery entrapment syndrome. J Med Radiat Sci. Sep 2015;62(3):226-9. doi:10.1002/jmrs.121
8. American College of Radiology. ACR Appropriateness Criteria® Suspected Lower Extremity Deep Vein Thrombosis. American College of Radiology. Updated 2018. Accessed January 23, 2023. https://acsearch.acr.org/docs/69416/Narrative/
9. Karande GY, Hedgire SS, Sanchez Y, et al. Advanced imaging in acute and chronic deep vein thrombosis. Cardiovasc Diagn Ther. Dec 2016;6(6):493-507. doi:10.21037/cdt.2016.12.06
10. Katz DS, Fruauff K, Kranz A-O, Hon M. Imaging of deep venous thrombosis: A multimodality overview. Applied Radiology, Anderson Publishing. Updated March 5, 2014. Accessed January 23, 2023. https://www.appliedradiology.com/articles/imaging-of-deep-venous-thrombosis-a- multimodality-overview
11. American College of Radiology. ACR Appropriateness Criteria® Soft Tissue Masses. American College of Radiology. Updated 2022. Accessed January 23, 2023. https://acsearch.acr.org/docs/69434/Narrative/
12. Wani ML, Ahangar AG, Ganie FA, Wani SN, Wani NU. Vascular injuries: trends in management. Trauma Mon. Summer 2012;17(2):266-9. doi:10.5812/traumamon.6238
13. Fonseka CL, Galappaththi SR, Abeyaratne D, Tissera N, Wijayaratne L. A Case of Polyarteritis Nodosa Presenting as Rapidly Progressing Intermittent Claudication of Right Leg. Case Rep Med. 2017;2017:4219718. doi:10.1155/2017/4219718
14. Verikokos C, Karaolanis G, Doulaptsis M, et al. Giant popliteal artery aneurysm: case report and review of the literature. Case Rep Vasc Med. 2014;2014:780561. doi:10.1155/2014/780561
15. Menke J, Larsen J. Meta-analysis: Accuracy of contrast-enhanced magnetic resonance angiography for assessing steno-occlusions in peripheral arterial disease. Ann Intern Med. Sep 7 2010;153(5):325-34. doi:10.7326/0003-4819-153-5-201009070-00007
16. Murphy EA, Ross RA, Jones RG, et al. Imaging in Vascular Access. Cardiovasc Eng Technol. Sep 2017;8(3):255-272. doi:10.1007/s13239-017-0317-y
17. Madani H, Farrant J, Chhaya N, et al. Peripheral limb vascular malformations: an update of appropriate imaging and treatment options of a challenging condition. Br J Radiol. Mar 2015;88(1047):20140406. doi:10.1259/bjr.20140406
18. Obara P, McCool J, Kalva SP, et al. ACR Appropriateness Criteria® Clinically Suspected Vascular Malformation of the Extremities. J Am Coll Radiol. Nov 2019;16(11s):S340-s347. doi:10.1016/j.jacr.2019.05.013
19. Conte MS, Bradbury AW, Kolh P, et al. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg. Jun 2019;69(6s):3S-125S.e40. doi:10.1016/j.jvs.2019.02.016
20. Cooper K, Majdalany BS, Kalva SP, et al. ACR Appropriateness Criteria(®) Lower Extremity Arterial Revascularization-Post-Therapy Imaging. J Am Coll Radiol. May 2018;15(5s):S104-s115. doi:10.1016/j.jacr.2018.03.011
21. Resnick HE, Lindsay RS, McDermott MM, et al. Relationship of High and Low Ankle Brachial Index to All-Cause and Cardiovascular Disease Mortality. Circulation. 2004;109(6):733-739. doi:doi:10.1161/01.CIR.0000112642.63927.54
22. Dasgupta A, Mazumdar A. Peripheral artery disease in the lower extremities - prevalence and epidemiology. online e-Journal European Society of Cardiology. March 14, 2018 2018;16(4)
23. 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(2):177-183. doi:10.1001/jama.2018.8357

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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