Study Supports Contrast-Enhanced Ultrasound for Post-EVAR Surveillance

October 27, 2016—A study demonstrating that contrast-enhanced ultrasound (CEUS) can replace CTA for surveillance after endovascular aneurysm repair (EVAR) was published by Kim Kargaard Bredahl, MD, et al online ahead of print in the European Journal of Vascular and Endovascular Surgery (EJVES).

The investigators stated that the background of the study is that CTA is considered the standard imaging modality for mandatory post-EVAR surveillance; however, patients are exposed to ionizing radiation and nephrotoxic contrast medium with CTA.

The study’s primary aim was to determine the diagnostic efficacy of duplex ultrasound (DUS) and CEUS, using CTA as the gold-standard comparator. The secondary aim was to determine the clinical consequences of endoleaks missed by DUS and CEUS or by CTA.

As summarized in EJVES, the investigators prospectively and consecutively enrolled all patients undergoing EVAR for treatment of an aortoiliac aneurysm between August 1, 2011 and October 31, 2014. CEUS was added to the existing surveillance protocol, which included DUS, plain abdominal x-ray, and CTA at 3 and 12 months after stent implantation.

The investigators reported that in 278 patients, endoleaks were detected in 68, 69, and 46 cases by CTA, CEUS, and DUS, respectively. The sensitivity and specificity of DUS and CEUS were 46% and 93%, and 85% and 95%, respectively. CEUS and CTA were diagnostically equivalent, as opposed to DUS and CTA (P = .002). 

Endoleaks detected by CTA led to reintervention in 11 patients (4%). These endoleaks were also detected by CEUS; however, three out of 11 patients were missed by DUS and underwent reintervention (limb extension, recuffing, and attempts to coil lumbar leaks). Endoleaks missed by CEUS or CTA were type 2 endoleaks without sac expansion.

In surveillance programs after EVAR, a diagnostic CEUS examination may replace CTA, concluded the investigators in EJVES.