EXPERIMENTAL EVALUATION OF A NEW SELF-EXPANDING PATENT DUCTUS-ARTERIOSUS OCCLUDER IN A CANINE MODEL

PURPOSE: A new self-expanding patent ductus arteriosus (PDA) occluder was designed, MATERIALS AND METHODS: Percutaneous closure of surgicall y created aortopulmonary shunts was attempted in 19 dogs, The occlusio n device consisted of a nitinol wire frame tightly woven into a cylind er with a flat retention disc, A polyester-filled frame was used in th e last six procedures, A 6-F introducing sheath was advanced across th e aortopulmonary conduit into the descending thoracic aorta, The prost hesis (attached on a stiff delivery cable) was advanced through the in troducing sheath, The retention disc was first released in the descend ing thoracic aorta, then the cylindrical device frame was expanded wit hin the conduit by withdrawing the sheath, RESULTS: Subtotal misplacem ent into the descending aorta occurred in one procedure (overall techn ical success rate, 95%), and one animal died before the 1-week follow- up, Complete angiographic shunt closure was achieved in seven of 18 (3 9%) animals at 30 minutes, 12 of 17 (71%) animals at 1 week, 14 of 17 (82%) animals at 1 month, and 11 of 12 (92%) animals at 3 months, Sign ificantly higher 30-minute closure rates occurred with polyester-fille d occluders compared with nonfilled occluders (five of five [100%] vs one of 13 [15%]; P = .002), Persistent shunt at 3 months occurred in o nly one nonfilled device (6%), In the remaining 16 animals, both orifi ces of the shunt were covered by a smooth glistening neoendothelium at postmortem examination, CONCLUSION: This device combines the advantag es of small delivery system, easy placement, self-centering, and repos itionability, Immediate shunt closure can be reliably accomplished wit h the polyester-filled prosthesis.