Hemodynamic function of the Hancock standard orifice aortic valve bioprosthesis

Reports that the hemodynamic performance of the standard orifice aortic bioprosthesis in less than optimal have prompted recommendations that mechanical prosthesis or anulus-enlarging procedures be used in adult patients with a small aortic root. The hemodynamic function of the Hancock bioprosthesis was evaluated in 77 patients who underwent cardiac catheterization of rest and with isoproterenol infusion (15 patients) an average of 6 months after operation. The average peak systolic gradient (basal conditions) was 7 mm Hg (range 0 to 37 mm Hg); 35 patients had no resting gradient. Fifteen patients received 21 mm diameter valves and had an average systolic valve gradient of 10 mm Hg (range 0 to 30 mm Hg); the average effective valve orifice area was 1.27 +/- 0.17 cm2 for 21 mm, 1.46 +/- 0.11 cm2 for 23 mm, 1.72 +/- k0.20 cm2 for 25 mm, and 1.97 +/- 0.06 for 27 mm bioprostheses. Isoproterenol infusion, elevating cardiac output 66%, increased the peak systolic gradient from an average of 11 mm Hg (range 0 to 37 mm Hg) to 44 mm Hg (range 10 to 85 mm Hg). It is concluded that small-diameter (21 and 23 mm) Hancock bioprostheses can be used with acceptable clinical and hemodynamic function in patients with a small body surface area.