PERIOPERATIVE ASSESSMENT OF AORTIC HOMOGRAFT, TORONTO STENTLESS VALVE, AND STENTED VALVE IN THE AORTIC POSITION

We investigated aortic valve hemodynamic performance and perioperative left ventricular function in 50 patients (mean [+/-SD] age, 64 +/- 9 years; 34 men, 16 women) undergoing elective aortic valve replacement, using an aortic homograft (n = 20), a Toronto stentless porcine valve (n = 20), or a stented bioprosthesis (n = 10), by transesophageal ech ocardiography combined with high-fidelity cavity pressure recordings a nd thermodilution cardiac output measurements. Thirty-nine patients ha d aortic stenosis; 11 had predominant regurgitation. Thirteen patients with concomitant coronary artery stenosis underwent grafting. Left ve ntricular mass index in all patients was 280 +/- 110 g/m(2). The trans valvular pressure drop and energy consumption were significantly highe r with stented than stentless valves (5 with aortic homograft and 11 w ith Toronto valve, with matched age and valve size; 20 +/- 12 versus 3 +/- 9 mm Hg; 21% +/- 13% versus 8% +/- 8%, both p < 0.01). However, t here was no difference in these variables between the Toronto valve an d the aortic homograft (3 +/- 12 versus 2 +/- 10 mm Hg; 5% +/- 14% ver sus 2% +/- 12%, both p > 0.05), although the Toronto valves (normalize d to body surface area) were larger than the aortic homografts (14.4 /- 1.9 versus 12.6 +/- 1.8 mm/m(2), p < 0.01). There was no significan t difference in left ventricular stroke volume index or stroke work in dex in the systemic circulation, either between stentless and stented valves or between aortic homografts and Toronto valves, although the c ross-clamp time required to insert a stentless valve was 20 minutes lo nger than that for a stented valve. In conclusion, the stentless valve has a significantly superior hemodynamic performance to that of the s tented valve, but left ventricular function was not compromised by a l onger ischemic time. The early performance of the Toronto stentless po rcine valve resembles that of the aortic homograft, but long-term foll ow-up is needed.