Experimental evaluation of a new self-expanding patent ductus arteriosus occluder in a canine model

A new self-expanding patent ductus arteriosus (PDA) occluder was designed.

Percutaneous closure of surgically created aortopulmonary shunts was attempted in 19 dogs. The occlusion device consisted of a nitinol wire frame tightly woven into a cylinder with a flat retention disc. A polyester-filled frame was used in the last six procedures. A 6-F introducing sheath was advanced across the aortopulmonary conduit into the descending thoracic aorta. The prosthesis (attached on a stiff delivery cable) was advanced through the introducing sheath. The retention disc was first released in the descending thoracic aorta, then the cylindrical device frame was expanded within the conduit by withdrawing the sheath.

Subtotal misplacement into the descending aorta occurred in one procedure (overall technical success rate, 95%), and one animal died before the 1-week follow-up. Complete angiographic shunt closure was achieved in seven of 18 (39%) 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. Significantly higher 30-minute closure rates occurred with polyester-filled occluders compared with nonfilled occluders (five of five [100%] vs one of 13 [15%]; P = .002). Persistent shunt at 3 months occurred in only one nonfilled device (6%). In the remaining 16 animals, both orifices of the shunt were covered by a smooth glistening neoendothelium at postmortem examination.

This device combines the advantages of small delivery system, easy placement, self-centering, and repositionability. Immediate shunt closure can be reliably accomplished with the polyester-filled prosthesis.