EFFICACY OF AORTIC VALVE REPLACEMENT USING THE St. Jude Medical-HP VALVE FOR PATIENTS WITH A SMALL AORTIC ANNULUS

[Introduction] The ideal mechanical prosthesis to replace the aortic valve in patients with a small aortic annulus remains controversial. The purpose of this study is to compare hemodynamic performance and clinical results of the SJM-HP with those of standard valves(Bjork-Shiley(B-S) and standard SJM) in patients with a small aortic annulus who received a patch enlargement. [Materials and Methods] Between 1975 and 1998, 33 patients received a 21mm SJM-HP (16 patients), a 21mm standard SJM(5 patients), or a 23mm B-S(12 patients) aortic prosthesis. For all patients who had one of the standard valves implanted the patch enlargement was performed using Nicks' method. Either doppler echocardiography or catheterization were performed both before and after the operation, and readings of flow velocity, and the pressure gradient across the valve were measured. [Results] There were no differences in flow velocity or pressure gradient between the groups. Moreover, we experienced no operative mortalities or significant perioperative complications. Peak and mean pressure gradients, along with flow velocity, in the 21mm SJM-HP group were significantly lower than the 21mm SJM group, in early postoperative and later follow-up periods. However, there were no statistical differences in these indices between the 21mm SJM-HP group and the 23mm B-S group seen at follow-up. [Conclusion] Based on our results, we believe that the 21mm SJM-HP should be selected for AVR when the preoperative aortic annulus diameter is approximately 22mm and for patch enlargement for a small aortic annulus when the preoperative aortic annulus diameter is below 20mm.