Nonoperative closure of the patent ductus arteriosus: the Frankfurt experience

Transvenous closure of patent ductus arteriosus with Ivalon plugs. Multicenter experience with a new technique

RATIONALE AND OBJECTIVE

The authors assess the clinical efficacy of transvenous closure of patent ductus arteriosus (PDA) with a new plug consisting of Ivalon foam and a platinum/iridium frame with four aortic and two pulmonary nitinol struts. The most widely used devices for transcatheter treatment of PDA (Porstmann plug, Rashkind umbrella, Botallo occluder, coils) have specific limitations inherent to their design (e.g., transarterial approach, residual shunts, limited retrieval).

METHODS

Between 1994 and 1997, PDA closure was attempted in 33 children and 67 adolescents and adults in 7 clinical centers; PDA diameter was 2 to 11 mm. Plug diameter was 6 to 20 mm, and 8 to 16 F venous sheaths were used for insertion.

RESULTS

Placement was successful in 98% (with a single plug in 88%, and a second or third plug in 10%) and unsuccessful in 2%. Plugs were retrieved after malpositioning in 12 of 12 patients and after pulmonary embolization in 2 of 3 patients. One patient underwent surgery for removal of an embolized plug. Complete PDA closure was proved by aortography and color Doppler echocardiography in 85% (40 of 43 patients with a PDA 2-3.9 mm, 30 of 36 patients with a PDA 4-5.9 mm, and 15 of 21 patients with a PDA 6-11 mm). During a median follow-up interval of 16 months, there were no complications (infection, hemolysis, fracture, embolization).

CONCLUSION

The new plug device can be used successfully in patients with a PDA diameter up to 11 mm. Further investigations are underway to determine the definite clinical value of this technique.

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 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.

RESULTS

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.

CONCLUSION

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.