"Our findings support the addition of contrast-enhanced ultrasound as a complementary tool in the follow-up of these patients," said Rosa Gilabert, M.D., Ph.D., from the Hospital Clinic at the University of Barcelona in Spain.
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, such as smoking, high blood pressure, a positive family history, high cholesterol, peripheral vascular disease or obesity. The aneurysm places stress on the wall of the aorta that can lead to wall rupture. Mortality rates after rupture are high.
Endovascular repair of abdominal aortic aneurysms (EVAR) involves placement of a stent graft called an endograft into the vessel to bypass the area of the aorta weakened by the aneurysm and keep it from rupturing. EVAR has substantially reduced mortality around the time of surgery when compared with open repair. However, EVAR effectiveness can be compromised by a complication, known as an endoleak, which carries the subsequent risk of rupture of the aneurysm sac.
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.
"The main advantage of contrast-enhanced ultrasound is that it offers the possibility of real-time exploration of EVAR-treated patients, without the exposure to ionizing radiation or the risk of damage to the kidneys," she said. 'To avoid the potential risk of kidney toxicity is particularly important, because impaired renal function is not uncommon in these patients."
The researchers 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.
"These results support that contrast-enhanced ultrasound can be integrated in the EVAR follow-up," Dr. Gilabert said.
"Evaluation of Abdominal Aortic Aneurysm after Endovascular Repair: Prospective Validation of Contrast-enhanced US with a Second-Generation US Contrast Agent." Collaborating with Dr. Gilabert were Laura Buñesch, M.D., María Isabel Real, M.D., Ph.D., Ángeles García-Criado, M.D., Ph.D., Marta Burrel, M.D., Ph.D., Juan Ramón Ayuso, M.D., Ph.D., Marta Barrufet, M.D., Xavier Montaña, M.D., Ph.D., and Vicenç Riambau, M.D., Ph.D.
Radiology is edited by Herbert Y. Kressel, M.D., Harvard Medical School, Boston, Mass., and owned and published by the Radiological Society of North America, Inc. (http://radiology.rsna.org/)
RSNA is an association of more than 48,000 radiologists, radiation oncologists, medical physicists and related scientists committed to excellence in patient care through education and research. The Society is based in Oak Brook, Ill. (RSNA.org)
For patient-friendly information on ultrasound, visit RadiologyInfo.org.
Linda Brooks | EurekAlert!
Making small intestine endoscopy faster with a pill-sized high-tech camera
23.08.2019 | Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM
Traumas change perception in the long term
19.08.2019 | Rheinische Friedrich-Wilhelms-Universität Bonn
Since their experimental discovery, magnetic skyrmions - tiny magnetic knots - have moved into the focus of research. Scientists from Hamburg and Kiel have now been able to show that individual magnetic skyrmions with a diameter of only a few nanometres can be stabilised in magnetic metal films even without an external magnetic field. They report on their discovery in the journal Nature Communications.
The existence of magnetic skyrmions as particle-like objects was predicted 30 years ago by theoretical physicists, but could only be proven experimentally in...
Theoretical physicists at Trinity College Dublin are among an international collaboration that has built the world's smallest engine - which, as a single calcium ion, is approximately ten billion times smaller than a car engine.
Work performed by Professor John Goold's QuSys group in Trinity's School of Physics describes the science behind this tiny motor.
Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.
Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...
Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics
The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...
Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.
Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...
16.08.2019 | Event News
14.08.2019 | Event News
12.08.2019 | Event News
23.08.2019 | Medical Engineering
23.08.2019 | Power and Electrical Engineering
23.08.2019 | Life Sciences