Angiography in the Evaluation of Abdominal Aortic Aneurysm

Angiography in the Evaluation of Abdominal Aortic Aneurysm

Kelley Hodgkiss-Harlow, Murray L. Shames and Dennis F. Bandyk

Arterial imaging plays an essential role in evaluating patients for open surgical or endovascular repair of abdominal aortic aneurysms (AAAs). A number of imaging modalities exist to identify and characterize the AAA, including ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and catheter-based arteriography. Because each imaging technique has distinct advantages and limitations, clinical application depends on the patient’s clinical status, the need for AAA repair, and suspected visceral or branch artery occlusive disease.

Maximal aneurysm diameter is the primary determinant for AAA treatment in asymptomatic patients, and it can be accurately measured with each of the aforementioned imaging techniques except arteriography. Although catheter-based angiography accurately depicts the aorta lumen, the presence of mural thrombus in the sac obscures the actual aneurysm diameter. Details of aneurysm morphology, relationship to visceral arteries, quality of the aortic wall, presence of intramural thrombus, and associated occlusive disease are better evaluated with contrast-enhanced CT or MRI. CT angiography (CTA) has largely replaced traditional diagnostic angiography for initial patient assessment because anatomic criteria (proximal neck length, iliac artery diameter) for endovascular repair of AAA can be determined.

Indications for Catheter-Based Arteriography

Accepted indications for additional imaging before intervention recognize the common occurrence of associated arterial occlusive disease in patients with AAAs (Box 1 and Table 1). The role of catheter-based arteriography is to accurately characterize concomitant branch artery disease and aid in determining the hemodynamic significance of identified occlusive lesions by quantitating pressure-gradient measurements. Angiography remains an essential component of endovascular treatment of branch artery stenosis or hypogastric artery aneurysms. Use of rotational arteriography allows three-dimensional (3-D) reconstruction of the visceral aorta segment and improved characterization of occlusive lesions with rotating views of the image. Associated splanchnic or renal occlusive disease can be treated either before an open surgical repair or concurrent with an endovascular repair. Angiography is invasive and is associated with a variety of complications that preclude its routine use for AAA diagnosis (Table 2). One particular complication deserves note: Power injection of contrast into the artery of Adamkiewicz, which can produce permanent lower limb paralysis, can be avoided by appropriately positioning the catheter below the T12 vertebra and verifying that the catheter is freely moving in the aorta.

Jul 15, 2018 | Posted by in CARDIOLOGY | Comments Off on Angiography in the Evaluation of Abdominal Aortic Aneurysm
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