A Complication of Valve Replacement

SINCE the introduction of artificial heart valves, investigators have been continuously modifying them, endeavoring to eliminate complications associated with their use. -3 The Starr-Edwards ball-valve prosthesis was the first to be widely accepted; however, problems due to its weight, cage size, and resistance to blood flow have stimulated the search for a better prosthetic device. In spite of this effort, the ideal heart valve has not been developed. Recently, a "caged-lens" design has become the prosthesis of choice in some centers. One type, Cross-Jones, consists of a titanium frame, a silicone rubber lens-shaped disc, and a woven Teflon fixation flange. The freely floating disc is held in position over the valve seat by a cage of three titanium legs3 (fig. 1 left). The silicone rubber lens is reinforced by a titanium ring molded within it. The ring prevents excessive deformation of the lens, and, being 0.010 inch larger in diameter than the valve orifice, it prohibits the lens from slipping through the orifice under high closing pressure.