TRANSCATHETER OCCLUSION OF PATENT DUCTUS-ARTERIOSUS USING A NEWLY DEVELOPED SELF-EXPANDING DEVICE - EVALUATION IN A CANINE MODEL

RATIONALE AND OBJECTIVES. A new occlusion device designed for use in a patent ductus arteriosus was tested in an animal model. METHODS. The device consists of a self-expanding conical-shaped stainless steel mes h, with hooks encircling the expanding end acting to secure the device within the ductus, A screw thread at the apex allows attachment to a stylet, and a 6 F delivery system is used, Placement of the device was attempted in 20 canines that previously had a vascular graft surgical ly inserted between the descending thoracic aorta and main pulmonary a rtery, creating the patent ductus model. Angiographic follow-up at reg ular intervals was performed over a 3-month period. RESULTS. Early cas es resulted in device misplacement and migration because of inaccurate assessment of ductus position and size, In 15 canines the device was placed within the ductus and regularly assessed over the 3-month place ment period, Ductus occlusion occurred within 1 week in 12 of 13 dogs (92%) when device placement was considered ideal, In two dogs where si gnificant protrusion of the device from the ductus was evident (either into the aorta or main pulmonary artery) ductus closure was delayed b ut present by 3 months, resulting in a 93% overall closure rate at thi s time, In one dog, the ductus remained partially opened. CONCLUSIONS. This self-expanding patent ductus arteriosus occlusion device is prom ising, The 6 F delivery system is advantageous over other devices curr ently available, making it more suited for use in the pediatric popula tion, Accurate assessment of the ductus is imperative, however, to ena ble correct device sizing, The screw thread system allows the device t o be repositioned if desired prior to deployment.