Abstract: An apparatus for closure of an opening or isolation of a structure in the cardiovascular system. The apparatus generally includes an occluding segment, a delivery segment and a control segment. The occluding segment may be composed of one or more independently inflatable members which are detachably or permanently attached to a distal portion of the delivery segment. The occluding segment may contain a stem-like member, which constrains expansion of the inflatable member in one or more directions. The apparatus is intended to enable a combination of the following: inflation of the occluding segment, ‘over the wire’ advancement, detachment of a portion of the device, and steerability. Finally, the control segment may contain components such as ports, handles, and other mechanisms which enable safe and effective implantation of the device.