Background and aim of the study: Stentless porcine valves are consider
ed to have a superior hemodynamic performance when compared with stent
ed bioprostheses. In the present study we report our initial experienc
e with the Edwards Prima stentless valve (EPSV), focusing on the hemod
ynamic performance of this device evaluated by means of transthoracic
two-dimensional (2D) Doppler echocardiography. Methods: Between Decemb
er 1994 and August 1995, 23 patients underwent aortic valve replacemen
t with the EPSV implanted in the subcoronary position. Evaluation of h
emodynamic performance of the EPSV was assessed before discharge (one
week) and at six months follow up by means of transthoracic 2D echocar
diography. Results: There were no operative deaths and no major postop
erative complications. Hemodynamic data were available for comparison
at one week and six months in 18 patients (23 mm, n = 8; 25 mm, n = 10
). For 23 mm EPSV, peak gradient varied from 42.7 +/- 10.2 mmHg at one
week to 29.7 +/- 9.8 mmHg at six months (p=0.01); for 25 mm EPSV, pea
k gradient varied from 33.6 +/- 10.6 mmHg at one week to 29.5 +/- 6.5
mmHg at six months (p = N.S.). Conclusions: The EPSV, when used in the
subcoronary position, has been associated with high early transprosth
etic gradients which only partly regress at six months. Gradients are
probably caused by the inward folding of the Dacron cloth beneath the
right coronary ostium and were recorded especially in patients with ao
rtic stenosis in whom the right coronary ostium was close to the aorti
c annulus. In such patients alternative implantation techniques should
be considered.