Mark Quentin Smith MD, Presenter: Nothing to Disclose

W. Brian Hyslop MD, PhD, Abstract Co-Author: Nothing to Disclose

Louise Michelle Henderson, Abstract Co-Author: Nothing to Disclose

Hyeon Yu MD, Abstract Co-Author: Nothing to Disclose

Julia R. Fielding MD, Abstract Co-Author: Nothing to Disclose

To determine the incidence of clinically significant non-vascular findings on contrast-enhanced CT angiography in patients who have undergone EVAR.

We retrospectively reviewed the radiology reports of the initial abdominopelvic contrast-enhanced 64-slice MDCT scans in 1000 patients who presented with an abdominal aortic aneurysm between January 1, 2008 and December 31, 2011. We followed the imaging results for a minimum of two years to determine the significance of each finding. Incidental findings that were benign or unlikely to undergo follow-up were placed into the low significance group. Benign findings that had the potential to warrant medical or surgical intervention were classified as having moderate importance. Findings that required specialized imaging, biopsy or therapeutic intervention as well as indeterminate findings were placed within the high significance category. We examined the proportion of incidental findings in each of these categories by age and location and calculated the 95% confidence intervals to assess differences among subgroups.

There were a totla of 2374 incidental findings in 847 patients: 1877 were of low significance, 357 were of moderate significance, and 140 were grouped in the high significance category. There were no differences in the proportion within each category of incidental findings by age group (<65 versus 65+). Of the high significance findings, 32 incidental malignancies (3.2%, 95% CI: 2.3-4.5%) were found, with renal cell carcinoma being the most common (n=11), followed by metastatic disease (n=5). 22 of the 32 patients had N0M0 disease at initial staging.

Our rate of incidental cancers found on abdominopelvic imaging of 3.2% is low, but is greater than the 0.56-1.25% reported in virtual colonoscopy studies. This may be secondary to the older mean age of this population. In addition, contrast-enhanced scans allow for definitive diagnosis of malignant lesions.

The presence of incidental cancers on endovascular CT angiography highlights the need for careful radiologic review of all vascular imaging studies.

Smith, M, Hyslop, W, Henderson, L, Yu, H, Fielding, J, Incidence of Significant Non-vascular Findings (Neoplastic and Non-neoplastic) in Patients Who Have Undergone Endovascular Aortic Aneurysm Repair (EVAR).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015273.html