Echocardiographic imaging of stentless aortic valve prostheses

Homografts and stentless xenografts are increasingly used in aortic valve surgery. Echocardiography technicians and cardiologists have to know what they will find when performing an echo-Doppler examination in patients who received a stentless valve. We therefore evaluated echocardiographic images of 74 patients who received a Freestyle stentless bioprosthesis with three techniques and a follow-up of 2 years in two high-volume hospitals. Of the patients studied, 81% were operated using the subcoronary technique, 12% using the root-inclusion technique, and 7% using the full-root technique.

Transvalvular gradients across the stentless valves were low: 8.0 mmHg when implanted with the subcoronary technique, 8.2 +/- 5.1 mmHg using the root-inclusion technique, and 6.5 mmHg using the full-root technique. Trivial aortic insufficiency (grade 1) was observed in 10.7% of the patients (8.9% for the subcoronary technique, 13% for the root-inclusion technique, and 0% for the full-root technique). When the bioprosthesis was implanted using the subcoronary technique or the root-inclusion technique, the prosthesis was placed inside the recipient aortic root. Using these techniques, a lumen between the double layer of the xenograft and the aortic wall could be observed. With the root-replacement technique, the porcine root became the most proximal part of the ascending aorta. As the native aortic wall was removed, in most cases, no double lumen could be observed with imaging of the ascending aorta.