Description
Purpose
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. It is not appropriate as a screening tool for asymptomatic patients without a previous diagnosis.

Special Note
For conditions where both abdomen and pelvis imaging are needed and/or the disease process is reasonably expected to involve both the abdomen and pelvis, requests should be resubmitted as CPT 74174. See Evolent Clinical Guideline 069 for Abdomen Pelvis CTA for coverage indications.

When vascular imaging of the aorta and both legs with Runoff is desired (sometimes incorrectly requested as Abd/Pelvis CTA & Lower Extremity CTA), only one authorization request is required, using CPT Code 75635 CT Angiography, Abdominal Aorta with Lower Extremity Runoff. This study provides for imaging of the abdomen, pelvis, and both legs.

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.

Policy

INDICATIONS FOR PELVIS CTA (ANGIOGRAPHY)
Venous Disease

• Evaluation of suspected pelvic vascular disease or pelvic congestive syndrome when findings on ultrasound are indeterminate¹
• Unexplained lower extremity edema (typically unilateral or asymmetric) with negative or inconclusive Abdomen and/or Pelvis CT²
• Evaluation of venous thrombosis in the inferior vena cava³
• Venous thrombosis if previous studies (such as ultrasound) have not resulted in a clear diagnosis⁴
• Suspected May-Thurner Syndrome (iliac vein compression syndrome) when imaging of the abdomen is not needed^5,6

Other Vascular Abnormalities seen on Prior Imaging Studies
For Findings Limited to the Pelvis

• Initial evaluation of inconclusive vascular findings on prior imaging
• For evaluation or monitoring of pelvic vascular disease when ultrasound is inconclusive^{5,7,8,9,10,11,12}
  • Includes abnormalities such as aneurysm, dissection, arteriovenous malformations (AVM), vascular fistula, intramural hematoma, compression syndromes and vasculitis involving any of the following: inferior vena cava, iliac arteries/veins and/or other pelvic blood vessels
• Suspected complications of known aneurysm as evidenced by clinical findings such as new onset of pelvic pain

Evaluation of Tumor

• When needed for clarification of vascular invasion from tumor^13,14
• For imaging of the deep inferior epigastric arteries prior to breast reconstructive surgery and abdominal imaging is not needed

Pre-Operative Evaluation^15,16

• Evaluation of interventional vascular procedures prior to endovascular aneurysm repair (EVAR), or for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• For imaging of the deep inferior epigastric arteries prior to breast reconstructive surgery and only pelvic imaging is needed (i.e. Abdomen CTA not requested)¹⁶
• Prior to uterine artery embolization for fibroids (MRA preferred)¹⁷
• Evaluation of vascular anatomy prior to solid organ transplantation

Post-Operative/Post-Procedural Evaluation

• 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.
• Evaluation of endovascular/interventional vascular procedures for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Evaluation of post-operative complications, e.g., pseudoaneurysms related to surgical bypass grafts, vascular stents, and stent-grafts in the pelvis
• Evaluation of post-operative complications of renal transplant allograft¹⁷

Combination Studies
Pelvis CTA (or MRA) and Pelvis CT

• When needed for clarification of vascular invasion from tumor (including suspected renal vein thrombosis)¹³
• Prior to uterine artery embolization for fibroids¹⁸

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)

Rationale/Background

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 non-compatible defibrillator or pacemaker), metallic fragments in a high-risk location, patient exceeds weight limit/dimensions of MRI machine.

Follow-Up of Asymptomatic, Incidentally Detected Iliac Artery Aneurysms
The definition of an iliac artery aneurysm (IAA) is dilatation to more than 1.5 times its normal diameter; in general, a common iliac artery ≥ 18 mm in men and ≥ 15 mm in women; an internal iliac artery (IIA) > 8 mm is considered aneurysmal.

Iliac Aneurysm Ultrasound Screening Intervals
From Wanhainen et al., 2019¹¹

• Aneurysm size 2.0 – 2.9 cm, every 3 years
• Aneurysm size 3.0 – 3.4 cm, annually
• Aneurysm size > 3.5 cm, every 6 months

References 

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, 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" 

History From 2019 Forward