Devices and techniques for modifying and maintaining a configuration of an occlusion device for the closure of physical anomalies, such as an atrial septal defect, a patent foramen ovale (PFO), and other septal and vascular defects are described. The devices and techniques relate particularly to, but are not limited to, modifying and maintaining a configuration of a PFO occluder made from a polymer tube. The proximal portion of a catch member may be provided with one or more protrusions, or arms, or bump or other raised element for securing the occluder in a partial or fully deployed configuration, either temporarily or permanently.