Early experience with stentless versus stented valves.

Abstract:

Background The Toronto stentless porcine valve (SPV) was designed to improve hemodynamics after aortic valve replacement by maximizing available flow area in comparison to stented valves (STD). Methods To assess possible hemodynamic differences between STD and SPV, 59 patients undergoing isolated aortic valve replacement (+/-coronary artery bypass graft) were prospectively evaluated by preoperative and 3-to 6-month postoperative echocardiography. Among these, 23 patients received a STD, whereas 36 received the Toronto SPV. Results The mean size (mm) of SPV implanted was larger (SPV, 26.6+/-2.1; STD, 24.0+/-2.9; P= 0.0002). Patients receiving STD valves were older and had a higher prevalence of coronary artery disease and congestive heart failure. There were no preoperative differences in left ventricular mass index (g/mo2), peak or mean pressure gradients (mmHg), effective orifice area (cm2), extent of fractional shortening (%), or velocity of circumferential shortening (cf/sec). ANOVA demonstrated a significant reduction in left ventricular mass index at 3 to 6 months (P=. 0001) but no differences in left ventricular mass index regression between groups (STD,-28.8+/-37.5; SPV,-31.2+/-32.4; P=. 36). Effective orafice area was increased postoperatively (P=. 0001), particularly among SPV cases (STD, 1.5+/-0.4; SPV, 1.9+/-0.7; P=. 01). Postoperative left ventricular mass index and mean pressure gradient were reduced (P=. 0001) but did not differ between groups. Fractional shortening and velocity of circumferential shortening were greater in the SPV patients at 3 to 6 months after aortic valve replacement (P=. 0004 and …

Año de publicación:

1997

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Fuente:

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