Echocardiographic parameters of the freestyle stentless bioprosthesis in aortic position: The European experience

The objective of this study was to determine normal Doppler and 2-dimension al characteristics of the Freestyle stentless aortic bioprosthesis. The Fre estyle aortic bioprosthesis is a new type of aortic xenograft, and experien ce is limited. We therefore determined the normal range of echocardiographi c and Doppler examinations of this valve. Three hundred thirty-nine consecu tive patients with a Freestyle aortic bioprosthesis underwent an echocardio graphic and Doppler examination according to a common protocol. Investigati ons were done within 4 weeks after operation, after 3 to 6 months, and afte r 1, 2, and 3 years. With a valve size from 19 to 27 mm, mean gradients dec reased from 7.9 +/- 5.1 mm Hg at discharge to 5.5 +/- 3.8 mm Hg after 3 to 6 months (P < .001). Thereafter, gradients remained stable. Effective orifi ce area 1 year after implantation was 1.59 +/- 0.58 cm(2) for the 21-mm val ves, 1.92 +/- 0.74 cm(2) for the 23-mm valves, 2.03 +/- 0.64 cm(2) for the 25-mm valves, and 2.52 +/- 0.72 cm(2) for the 27-mm valves CP (P < .001). T he performance index, the ratio of the measured effective orifice area in t he patient divided by the effective orifice area measured in vitro, increas ed from 67% +/- 20% at discharge to 82% +/- 29% after 1, 2, and 3 years. Pe rformance index was especially very high in the smaller-sized valves. After implantation with the subcoronary technique or root-inclusion technique, s mall cavities could be seen between the native aortic root and the Freestyl e valve. Doppler values were evaluated for the Freestyle stentless porcine bioprostheses in the aortic root. Gradients appear to be close to those mea sured in native valves over a time period of 3 years.