Laboratory and clinical experience with the caged lenticular valve.

INTRODUCTION S WCE 1958, v a n DESIGNS, MATERIALS, and techniques of insertion have been tested by the authors."' '4s a result of these studies, a caged lens prosthesis has been developed which offers some significant advantages over ball valve prostheses, particularly in the mitral area. Studies with the lenticular valve have been in progrgs since May, 1964, and minor improvements are being incorporated continuously in the present design. Valve Description The valve consists of a titanium frame and a woven Teflon fixation ring. Within the frame is a silicone rubber lens-shaped dim. The Teflon tixation ring for the mitral prosthesis is attached to the titanium cage in the form of a ring; whereas, in the aortic valve the prosthesis is extended ra*From the Department of Surgical Rcwarcb. Division of Surgery St. Luke's Hospital. Supported by GI&I HE-08325 from the National instituter of Health; The H e m A-iation of Northwettern Ohio; and the Eliuhth Severance Prentisr Foundation. Manufactured by Punco, Inc., Independence, Ohio. dially to form a flange (Fig. 1 ). The mitral and aortic valve sizes are listed in Table 1. Mitral sizes 65 through 85 correspond to available StamEdwards mitral valve sizes for adults. The low profile feature of the lens valve makes it possible to provide two sizes larger than the largest available ball valve. The orifice size of the ball valve is Limited by the size of the cage necessary to accommodate the ball which protrudes into the left ventricle. The free-floating lenticular disc is held in position over the valve orifice by a cage formed by three titanium legs. The silicone rubber lens is reinforced by a thin titanium ring which is molded in place within the lens. The ring is 0.010 inches larger in diameter than the valve orifice eliminating the posibiity that the lens will be forced through the valve orifice during high closing pressurn. The reinforcing ring is necessary to obtain a maximum reduction of lens thickness and weight. In addition, a softer silicone rubber can be used. If the reinforcing ring is elim-