Transvascular and intracardiac two-dimensional echocardiography.

Recent developments in transesophageal and catheter-based ultrasound instrumentation have allowed invasive ultrasound imaging. This experimental study presents a new application of invasive ultrasound, transvascular and intracardiac ultrasound imaging. In six pigs, we introduced a 7-mm, 5-MHz esophageal ultrasound probe into both the abdominal aorta and inferior vena cava and explored the imaging potential of this approach. Transvascular imaging from the aorta allowed visualization of the various cardiac structures, the neural canal and interspaces, and peritoneal anatomy. Advancement of the transducer to the level of the aortic valve or into the left ventricle yielded images of the cardiac valves and chambers. With transvascular imaging from the inferior and superior vena cava, the aorta, neural canal, pancreas, and liver were well visualized. Intracardiac imaging from the inferior venae cavae and various regions of the right heart, the left heart structures could be visualized. This in vivo feasibility study demonstrates the potential application of transducer-tipped catheters for transvascular and intracardiac imaging.