Can Preoperative Spiral CT Scans Alone Determine the Feasibility of Endovascular AAA Repair? A Comparison to Angiographic Measurements

Abstract

Considerable discrepancies exist between preoperative neck diameter and infrarenal aortic length measurements obtained from CT scans and angiograms used to evaluate candidates for endovascular aortic aneurysm repair. CT alone may not be adequate for predicting the feasibility of endovascular AAA repair.

Reporting standards for endovascular aortic aneurysm repair

“…14,15 Of note, in the absence of three-dimenstional reconstruction, aneurysm length is underestimated as determined from axial CT scan images. [16][17][18] Moreover, limitations also exist for angiography performed with a calibrated marker catheter. 14,19 Changes in dimension of the aortic neck.…”

Two-dimensional versus three-dimensional CT angiography in analysis of anatomical suitability for stentgraft repair of abdominal aortic aneurysms

“…Thus, using 2D-CTA pre-EVAR measurements, many patients might be considered unsuitable for EVAR treatment due to short or wide proximal AAA's neck (15). Many centers use conventional 2D-CTA combined with calibrated angiography for the pre-EVAR measurements but this technique has greater complexity, is more invasive and has obviously greater cost (16, 17). Obtaining all necessary, reliable and reproducible data from a single source as it is the 3D-CTA has significant value for the adequate pre-EVAR morphological evaluation.…”

Multidetector CT Angiography Versus Digital Subtraction Angiography for Aortoiliac Length Measurements Prior to Endovascular AAA Repair

“…Due to tortuous vessel anatomy, H4a was underestimated in DSA measurements, an observation made by other authors. 2,3,14,17,18,28 As a matter of fact, the correct length of the segments in the left iliac artery could not be determined precisely using the graduated catheter measurement because the catheter was inserted into the right femoral artery; thus, length measurements in the contralateral limb were limited. More reliable graduated catheter measurements would require bilateral punctures and insertion of two graduated catheters, which to our knowledge is not the current standard procedure in most centers.…”

“…Length can be estimated in longitudinal structures by calculating the difference between CT table positions. 14 However, this method is imprecise, especially when structures run oblique to the Z-axis or are tortuous, as is often the case in candidates for treatment of aneurysmal disease. Because conventional digital subtraction angiography (DSA) is a projection technique with parallax and limited field of view, the accuracy of 3dimensional (3D) length measurements is limited with this technique.…”