Improved cross-sectional echocardiographic technique for visualization of the retrocardiac descending aorta in its long axis. Normal findings and abnormalities in saccular and/or dissecting aneurysms.

The feasibility of using an improved ultrasonic technique for visualization of the retrocardiac descending thoracic aorta was studied in 50 consecutive patients. Both anterior and posterior aortic walls were well delineated in long as well as short axis in 92%. The mean length of the visualized portion of the retrocardiac aorta was 8.4 cm (range 4.5 to 13) and exceeded 6 cm in 40 of 46 patients. The mean diameter was 2.0 cm (range 1.3 to 2.7). Five patients with saccular (1 patient) and/or dissecting (all 5 patients) aneurysms involving the retrocardiac aorta were also examined. Abnormalities essentially identical to those seen with computerized tomography and aortography were noted. Intimal flaps were visualized by ultrasound in all 5 patients and were seen to oscillate reproducibly with the cardiac cycle, suggesting differential rates of filling of false and true lumens. This and other previous cross-sectional echocardiographic studies of the ascending aorta suggest that ultrasound may be useful in the initial evaluation of patients presenting with symptoms or signs suggestive of acute or chronic aortic disease.