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.

IMPORTANT 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 Abdominal Arteries CTA. This study provides for imaging of the abdomen, pelvis, and both legs The CPT code description is CTA aorto-iliofemoral runoff; abdominal aorta and bilateral ilio-femoral lower extremity runoff. 

When separate requests for CTA abdomen and CTA Pelvis are encountered for processes involving both the abdomen and pelvis (but do NOT need to include legs/runoff), they need to be resubmitted as a single Abdomen/Pelvis CTA (to avoid unbundling). Otherwise, the exam should be limited to the appropriate area (i.e., Abdomen OR Pelvis) that includes the area of concern.

INDICATIONS FOR ABDOMINAL ARTERIES CTA 

(For evaluation of a vascular abnormality in the abdominal aorta and lower extremities)

For evaluation of known or suspected abdominal, pelvic, or peripheral vascular disease^1-4

• 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 equivocal
• For critical limb ischemia with ANY of the below clinical signs of peripheral artery disease. Ultrasound imaging is not needed. If done and negative, it should still be approved due to a high false negative rate^{5, 6}
  • Ischemic rest pain
  • Tissue loss
  • Gangrene

Pre-operative evaluation

• Evaluation of interventional vascular procedures for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia 

Post-operative or post-procedural evaluation 

• Evaluation of post-operative complications, e.g., pseudoaneurysms related to surgical bypass grafts, vascular stents, and stent-grafts
• 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. 
• After stenting or surgery with signs of recurrent symptoms OR abnormal ankle/brachial index; abnormal or indeterminate arterial doppler; OR pulse volume recording⁷

Other Indications
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 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)

Chest CTA and Abdominal Arteries CTA Combos
To evaluate for an embolic source of lower extremity vascular disease. Echocardiography is also often needed, since the heart is the most commonly reported source of lower extremity emboli, accounting for 55 to 87 percent of events.

Rationale
High resolution computed tomography angiography (CTA) provides a cost-effective and accurate imaging assessment in the diagnosis and follow-up of patients with aortic dissections or peripheral arterial disease (PAD).

OVERVIEW

Suspected Peripheral Arterial Disease — CTA (or MRA) is an excellent tool to diagnose lower extremity peripheral arterial disease (PAD). Benefits include the fast-scanning time and accurate detection of occlusions and stenosis. According to the Society for Vascular Surgery guidelines, “Measurement of the ankle-brachial index (ABI) is the primary method for establishing the diagnosis of PAD. An ABI of ≤0.90 has been demonstrated to have high sensitivity and specificity for the identification of PAD compared with the gold standard of invasive arteriography.”² The presence of a normal ABI at rest and following exercise almost excludes atherosclerotic disease as a cause for leg claudication. ^1,8

When an ABI is >1.40 (suggesting noncompressible calcified vessels) and clinical suspicion is high, other tests such as toe-brachial index < 8, a resting toe pressure < 40 mm Hg, a systolic peak posterior tibial artery flow velocity < 10cm/s may be used. “In symptomatic patients in whom revascularization treatment is being considered, we recommend anatomic imaging studies, such as arterial duplex ultrasound, CTA, MRA, and contrast arteriography.”² This later statement is accompanied by a “B” (moderate) rating for the accompanying evidence (“A” = high, “C” = low) “In patients with limited renal function or planned surgical intervention, noninvasive imaging tests (particularly MRA and CTA) may obviate the need for diagnostic catheter angiography to visualize the location and severity of peripheral vascular disease.”¹

Follow-up imaging post vascular surgery procedures have not been well researched without clear surveillance protocols in place. Clinical exam, ABI and EUS within the first month of endovascular therapy are generally recommended to assess for residual stenosis, and again at 6 and 12 months, then annually. More sophisticated imaging with CTA, MRA, or invasive catheter angiography is reserved for complex cases.⁹

References

1. 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
2. Conte MS, Pomposelli FB, Clair DG, et al. Society for Vascular Surgery practice guidelines for atherosclerotic occlusive disease of the lower extremities: management of asymptomatic disease and claudication. J Vasc Surg. Mar 2015;61(3 Suppl):2s-41s. doi:10.1016/j.jvs.2014.12.009
3. Werncke T, Ringe KI, von Falck C, Kruschewski M, Wacker F, Meyer BC. Diagnostic confidence of run-off CT-angiography as the primary diagnostic imaging modality in  patients presenting with acute or chronic peripheral arterial disease. PLoS One. 2015;10(3):e0119900. doi:10.1371/journal.pone.0119900
4. American College of Radiology. ACR Appropriateness Criteria® Nonvariceal Upper Gastrointestinal Bleeding. American College of Radiology (ACR). Updated 2016. Accessed January 6, 2023. https://acsearch.acr.org/docs/69413/Narrative/
5. 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
6. 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
7. 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
8. Stoner MC, Calligaro KD, Chaer RA, et al. Reporting standards of the Society for Vascular Surgery for endovascular treatment of chronic lower extremity peripheral artery disease. J Vasc Surg. Jul 2016;64(1):e1-e21. doi:10.1016/j.jvs.2016.03.420
9. Zierler RE, Jordan WD, Lal BK, et al. The Society for Vascular Surgery practice guidelines on follow-up after vascular surgery arterial procedures. J Vasc Surg. Jul  2018;68(1):256-284. doi:10.1016/j.jvs.2018.04.018

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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