FLUID-DYNAMICS OF THE CARBOMEDICS KINETIC BILEAFLET PROSTHETIC HEART-VALVE

Objective: To compare hydrodynamic characteristics of a new bileaflet heart valve, the CarboMedics(R) KineticTM cardiac valve prosthesis, wi th those of a St. Jude Medical (SJM) heart valve. Methods: Hydrodynami c characteristics were determined in the mitral and aortic positions o f a Vivitro Systems pulse duplicator for size 23 Kinetic aortic valves , size 23 SJM aortic valves, size 29 Kinetic mitral valves and size 29 SJM mitral valves. Test conditions were 72 beats per min with cardiac outputs of 2, 5 and 7 1/min. Values of forward flow pressure drop (De lta P), regurgitant volume and energy loss were determined for each va lve. The test results for the two valve designs were compared by valve size. Results: The test results show that both the size 23 and size 2 9 Kinetic valves have 8-14% lower Delta P values and 5-10% greater eff ective orifice area (EGA) values. The size 29 Kinetic mitral valve has a 1-2 ml lower regurgitant volume, while the size 23 Kinetic aortic v alve has a 0.5 mi greater regurgitant volume than the corresponding SJ M valves. These factors combine to provide a 5-10% lower energy loss f or size 23 Kinetic aortic valves and a 15-25% lower energy loss for si ze 29 Kinetic mitral valves over the cardiac cycle than for correspond ing sizes of SJM valves. Conclusions: The Kinetic valve's fluid dynami cs are superior to equivalent sizes of SJM valves. This is especially impressive considering that the tissue annulus diameters for Kinetic v alves are approximately 0.5 mm less than equivalent size SJM valves. T he primary reasons for the superior hydrodynamic performance of Kineti c valves are (1) the larger orifices which result in lower forward flo w Delta P values and (2) the opening angles, which have been customize d for each valve size to minimize energy loss. (C) 1997 Elsevier Scien ce B.V.