Abstract 256: 2D Ultrasound Measurements Can Quantify Relative Single-Plane Circumferential Strain in an Abdominal Aortic Aneurysm Model
OBJECTIVES: Current size-based assessments of AAA rupture potential do not accurately identify all patients at risk. True AAA rupture potential is related to hemodynamic and geometric factors involving wall strain and compliance. Our hypothesis is that transcutaneous ultrasound-derived strain measurements can identify heterogeneous aortic wall compliance toward predicting future rupture.
METHODS: A latex phantom with changes in wall thickness (0.05-0.25 inches) to simulate AAA morphology was tested on an in vitro hemodynamic simulator. A GE Vivid i ultrasound machine interrogated the phantom under uniform physiologic, pulsatile conditions. The circumferential strain and radial strain of uniform wall phantom versus asymmetric wall phantom was quantified.
RESULTS: Maximum circumferential strain (MCS) of the uniform wall thickness phantom was evenly distributed at 3.5% with an AP wall strain difference of 2.3% (Figure 1A). Maximum radial strain (MRS) was evenly distributed at 9% with an AP wall strain difference of 0%. MCS and MRS of the asymmetric wall thickness phantom were significantly increased to 30% and 36% respectively at the thinned anterior wall. AP wall strain difference was 22% (Figure 1B) and 10% respectively.
CONCLUSIONS: Using transcutaneous 2D ultrasound, we were able to quantify changes in strain due to wall compliance in an AAA phantom. Further development of this technology may provide for a non-invasive method of characterizing the hemodynamic and geometric properties of an AAA to predict rupture potential.
- © 2012 by American Heart Association, Inc.