"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!
Reinforcement learning expedites 'tuning' of robotic prosthetics
18.01.2019 | North Carolina State University
Powerful microscope captures first image of nanoscaffold that promotes cell movement
14.01.2019 | Sanford Burnham Prebys Medical Discovery Institute
So-called bifacial stem cells are responsible for one of the most critical growth processes on Earth – the formation of wood.
Immune cells called macrophages are supposed to serve and protect, but cancer has found ways to put them to sleep. Now researchers at the Abramson Cancer...
The scientific and political community alike stress the importance of German Antarctic research
Joint Press Release from the BMBF and AWI
The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
23.01.2019 | Materials Sciences
23.01.2019 | Life Sciences
23.01.2019 | Life Sciences