The top of the device 333 has a slit 334 through the material for passing a balloon catheter or other device that may be used to expand or open the device 330 to an open configuration such as illustrated in FIG. 14B. The slit 334 will close when the catheter or expansion device is removed as illustrated in FIG. 14C. The PFO closure device 330 may be expanded to an open position whereby the sharp e