Valve sizer and method of use

#The present invention is directed to methods and apparatus for determining the appropriate replacement valve size when replacing a patient's cardiac valve.

#Replacement of a diseased or malfunctioning cardiac valve requires accurate sizing of the valve annulus. After the diseased or malfunctioning cardiac valve has been removed, the surgeon measures the patient's valve annulus to determine the appropriate replacement valve size.

#A conventional system for measuring a patient's valve annulus includes a number of varying size discs which can be attached to a rod. Each of the discs has a size which corresponds to an available valve size. The surgeon attaches one of the discs to the rod, inserts the disc into the patient's valve annulus and checks the fit of the disc within the valve annulus. If the surgeon is not satisfied with the fit, the surgeon removes the disc from the rod, attaches another disc to the rod and inserts the new disc into the valve annulus. This procedure is repeated until the surgeon is satisfied that the appropriate valve size has been identified.

#FIG. 1 is a perspective view of a first valve sizer having arms in an expanded position.

#FIG. 2 shows the first valve sizer of FIG. 1 with the arms in a retracted position.

#FIG. 3 is an exploded perspective view of the distal end of the first valve sizer.

#Referring to FIGS. 1 and 2, a first valve sizer 2 is shown. The valve sizer 2 has a tube 4 and an actuator 6 at the proximal end of the tube 4. A number of arms 8 below. FIG. 1 illustrates the arms 8 in an extended position and FIG. 2 illustrates the arms 8 in a retracted position. Rotation of the actuator 6 moves the arms 8 from the retracted position to the expanded position as will be described below.

#Referring to FIG. 3, the distal end of the valve sizer 2 is shown. The spacer 10 is attached to the bottom of a disc 12 which is attached to the tube 4. The spacer 10 includes slots 14 which guide movement of the arms 8 between the retracted and extended positions. The spacer 10 includes two recesses 16, only one of which is shown, which receive slotted discs 18. The slotted discs 18 are mounted to a rod 20 which extends through the tube 4. As will be discussed below, the rod 20 and tube 4 are coupled to the actuator 6 so that rotation of the actuator 6 rotates the rod 20 and slotted discs 18 with respect to the tube 4. Thus, the rod 20 and slotted discs 18 form a unitary structure while the tube 4, disc 12 and spacer 10 form another unitary structure.

#The arms 8 include pins 22 which are positioned in slots 24 of the slotted discs 18. Rotation of the rod 20 causes the pins 22 to slide in the slots 24 of the slotted discs 18 thereby moving the arms 8 in the slots 14 of the spacer 10 between the expanded and retracted positions. Referring to FIG. 4, a bottom view is shown with the arms 8 in the expanded position.