Ultrasonographic Surveillance with Selective CTA after Endovascular Repair of Abdominal Aortic Aneurysm

Purpose: To evaluate the agreement between color-coded duplex ultrasound (US) and computed tomographic angiography (CTA) in monitoring aneurysm diameter and detecting endoleaks after endovascular aneurysm repair (EVAR). Methods: From November 1998 to January 2007, 196 patients (191 men; mean age 72.4 years, range 52–88) underwent EVAR and were followed by CTA and US over a mean 3.9±2.4 years (range 0––8.9, median 3.4). Annual paired CTA and US examinations were reviewed to assess agreement in measuring maximum aneurysm transverse diameter and to evaluate diagnostic accuracy of US in detecting endoleak. Results: The 5-year cumulative endoleak incidence was 43.8% (72 patients). At first diagnosis, US detected 55/72 (76.4%) endoleaks; of the remaining 17, only 3 (4.3%) were clinically significant in terms of aneurysm enlargement. Pairing 709 annual CTA and US examinations from 184 patients showed a high agreement (k=0.96) between examinations in measuring maximum transverse diameter, with a mean difference between US and CTA of −2.5 mm. Conclusion: After the first year of follow-up, EVAR surveillance costs can be reduced by performing annual US examinations only. Keeping in mind that US underestimates diameter measurements, CTA can be reserved for patients with increasing or persistently stable aneurysm diameters.