Our purpose was to evaluate a new self-expanding device for closure of the
patent foramen ovale (PFO), A transeptal catheter passage through the flap
of the fossa ovalis was performed with a transeptal needle inside a cathete
r, creating a PFO in two minipigs, In an additional five animals, a natural
ly occurring PFO was found. The device is made from 0.005 inch nitinol wire
mesh with polyester fabric inside, similar in construction to the Amplatze
r atrial septal occluder, However, the left atrial disc is smaller (18 mm)
than the right atrial disc (26 mm), Both discs are connected by a very shor
t flexible waist (3 mm) that allows free movement of both retention discs,
Pulmonary and right atrial angiography were performed after placement, at 1
month, and at 3 months follow-up, Placement of the device was technically
successful in six animals. One animal died from ventricular fibrillation du
ring placement. Pulmonary angiography and echocardiography showed complete
occlusion of the PFO in six animals. Two animals were sacrificed after 1 mo
nth and four animals after 3 months. In the animals sacrificed at 1 month,
histopathological examination showed partial (n = 2) endothelialization, an
d in the 3 months follow-up group (n = 4) endothelialization was complete.
The device appears to be highly effective for occlusion of PFOs. This proce
dure may be performed as an outpatient procedure due to the small 7 Fr deli
very system sheath. Cathet. Cardiovasc. Intervent. 47:370-376, 1999. (C) 19
99 Wiley-Liss, Inc.