[Hemodynamic studies after the implantation of Hancock-heart valves (author's transl)]

Velocity profile, pressure gradient across the valve and blood flow have been measured in 10 patients after the implantation of bioprostheses of the sizes 27 and 29 millimeters in aortic position. According to these hemodynamic measurements the use of bioprostheses for the aortic valve replacement is recommendable. The low flow velocities in the area of the muscle containing valve cusp did not effect a detectable stenosis intraoperatively under the conditions of rest. The hemodynamic data showed no differences between the Hancock-Zuhdi and the Edwards-Carpentier bioprostheses. Despite of good hemodynamic conditions and a low risk of thromboembolic complications after the aortic valve replacement with bioprostheses reservation is recommended to its clinical use until the long term mechanical stability (more than 6 years) of the biological heart valve prosthesis has been secured.