The validity of current vascular imaging methods in the evaluation of aortic anastomotic aneurysms developing after abdominal aortic aneurysm repair

The aim of this cross-sectional study was to evaluate the validity of current imaging methods for diagnosing anastomotic false aneurysms (AFA) of the aorta. One hundred four patients who had undergone elective abdominal aortic aneurysm repair between January 1, 1985, and May 31, 1991, were studied. All of them were investigated for potential development of an aortic anastomotic aneurysm by B-mode ultrasonography, CT scanning, digital subtraction arteriography, and MRI. These findings were compared with results of color-coded Doppler imaging, which is considered the ''gold standard,'' and were subsequently classified as true positive or true negative. The accuracy of color Doppler ultrasound was independently evaluated by clinical examination of the patients, which was carried out for a mean period of 77.5 months during follow-up. On the basis of the data obtained and observations made during follow-up (mean 36.4 months), the sensitivity and specificity of the preceding imaging methods were estimated. Aortic anastomotic aneurysms were detected in two patients (1.9%). The sensitivity of all methods was 100% and specificity was as follows: 74.2% for ultrasound, 59.8% for nonenhanced CT scans, 85.4% for enhanced CT scans, and 99% for digital subtraction arteriograms. Color Doppler and MRI were 100% specific for ruling out aortic anastomotic aneurysms. In a comparison of the accuracy, estimated cost, safety, and the availability of each method, color Doppler appeared to be the diagnostic method of choice for identifying aortic anastomotic aneurysms after abdominal aortic aneurysm repair.