May 15, 2012
Monitoring Aneurysms: Less Risk
(Ivanhoe Newswire) — Monitoring aneurysms with a less invasive option! Researchers are saying a simple contrast ultrasound is the answer.
An abdominal aortic aneurysm occurs when the large blood vessel that supplies blood to the abdomen, pelvis and legs becomes abnormally large or balloons outward. Abdominal aortic aneurysms can occur in anyone, but are most commonly found in men over the age of 60 with one or more risk factors. The aneurysm places stress on the wall of the aorta that can lead to wall rupture. Mortality rates after rupture are high. Now, researchers have found contrast-enhanced ultrasound is an effective, noninvasive method for monitoring patients who undergo endovascular repair for abdominal aortic aneurysms.
Routine surveillance of endovascular stent placement with computed tomography (CT) angiography enables detection of potential complications in patients with endografts, but it also exposes the patient to ionizing radiation and potential kidney damage from the CT contrast agent.
Dr. Gilabert and colleagues studied ultrasound with a second-generation contrast agent and contrast-specific software as an alternative to CT angiography. The newer contrast agent consists of a suspension of microbubbles similar in size to red blood cells. Because of their small size, the microbubbles do not pass through the cells lining the inner surface of the blood vessel walls and thus provide a pure intravascular contrast agent that allows a real time investigation over several minutes, with the visualization of the dynamic enhancement pattern in real time
They evaluated the technique in 35 patients who underwent EVAR. The patients had CT angiography and contrast-enhanced ultrasound studies performed at one- and six-month follow-up and yearly thereafter. A total of 126 CT angiography and contrast-enhanced ultrasound studies were performed. Contrast-enhanced ultrasound had a sensitivity of 97 percent, a specificity of 100 percent and an accuracy of 99 percent for endoleak detection. The technique enabled correct classification of 26 of 33 endoleaks and did not miss any clinically important endoleak.
"To avoid the potential risk of kidney toxicity is particularly important, because impaired renal function is not uncommon in these patients," Dr. Gilabert was quoted as saying. "These results support that contrast-enhanced ultrasound can be integrated in the EVAR follow-up."