Clinical outcome of aortic valve replacement with 16-mm ATS-advanced performance valve for small aortic annulus

Various surgical techniques have been proposed to treat small aortic annulus. We have used small-diameter mechanical valves for small aortic annulus. The present study examined aortic valve replacement with small diameter mechanical valves to determine their effectiveness.

The study included 67 patients who underwent elective, isolated aortic valve replacement with ATS-Advanced Performance (AP) valves (ATS Medical, Inc, Minneapolis, MN) within our department. The patients were divided into two groups; patients receiving the 16-mm AP valve (16-mm group) and those receiving valves 18-mm AP or larger (>16-mm group).

The mean age of the 16-mm group was significantly higher than that of the >16-mm group. Body surface area was significantly smaller in the 16-mm group than the >16-mm group. We found no significant differences in preoperative conditions between the groups. The effective orifice area index of the mechanical valve was lower in the 16-mm group (0.87+/-0.06 vs 1.12+/-0.13 cm2/m2, p<0.0001). Six patients (40%) in the 16-mm group fell into the category of prosthesis-patient mismatch cases. Although the postoperative pressure gradient was higher in the 16-mm group (33.7+/-12.5 vs 23.16+/-8.78, p<0.01), left ventricular mass index and left ventricular ejection fraction at early and at late follow-up improved from the preoperative period in both groups. We found no significant differences in incidence of postoperative complications, including death.

We believe aortic valve replacement with small-diameter mechanical valves (the ATS-AP valves) in patients with a small annulus provides satisfactory remote prognosis. The use of mechanical valves in elderly patients is considered acceptable with strict clinical monitoring to prevent thromboembolism and anticoagulation therapy-induced complications.