BUTTONED DEVICE FOR THE TRANSVENOUS
OCCLUSION OF INTRACARDIAC DEFECTS
BACKGROUND OF THE INVENTION 5
1. Field of the Invention
The present invention relates to an intracardiac prosthesis, and more particularly, concerns a transvenously deliverable prosthesis for the occlusion of intracardiac defects. 10
2. Description of the Prior Art
Intracardiac defects occur relatively uncommonly in children but can cause significant problems including congestive heart failure, pulmonary hypertension or even death. They are treated medically initially but 15 quite frequently require surgical repair.
The surgical repair of intracardiac defects requires the use of general anesthesia, thoracotomy and heartlung machine. It is associated with significant morbidity and mortality, pain for the child and a significant ex- 20 pense for the parents.
For these reasons attempts were made before to close intracardiac defects without surgery. For example see King et al U.S. Pat. No. 3,874,388.
The late Dr. Rashkind invented an umbrella device 25 with hooks on the inside. The umbrella was introduced by a long catheter in the distal to the defect chamber it would open there and then would be pulled against the septal wall by the catheter till it was well hooked. Subsequently, it was released. 30
The method did not become popular, because it was associated with complications. Dr. Rashkind invented also a hookless two disk device. However details of the specifications-are not known and none of the above devices was patented. 35
We know though a great deal more about his double disk device, designed to occlude a vessel called patent ductus arteriosus. There are hooks involved and a bulky delivery system, requiring a very large for a child long sheath(llF or 3.7 mm for a 17 mm device). 40
SUMMARY OF THE INVENTION
The intracardiac prothesis of the present invention provides the means of the transvenous, without surgery, occlusion of intracardiac defects. The occlusion is 45 achieved by two independently buttoned components, the occluder and the counter-occluder or occluder holder.
In a preferred embodiment of the occluder aspect of this invention, the polyurethane form with the X shape 50 wire skeleton is folded so that the skeleton wires become nearly parallel. Thus the occluder can be introduced through a 7F(2.3 mm) or an 8F(2.7 mm) long sheath. The foam has a diameter of 2 mm, while the wire is size 0.018-0.025". The wire is Teflon covered in 55 order not to be thrombogenic.
The occluder is dipped into Heparin solution before the introduction. At the center of the occluder a 2 mm long double loop is attached. The loop is closed by a 1 mm diameter knot. In actuality this knot will be the 60 "button" during the attachment with the counteroccluder.
Another aspect of the present invention is the counter-occluder, or occluder holder. It is rhomboid in shape, made also by 2 mm thick poly-urethane foam and 65 a single 0.018" wire of equal diameter to the occluder. Foam and wire are stitched together by a continuously run suture. A 2 mm rubber piece of rhomboid shape is
sutured at the center of the occluder-holder. By applying two sutures along the rubber piece, the foam is covering the rubber, so there is no friction during the introduction and the advancement of the occluderholder in the long sheath.
A further aspect of the present invention is the release or loading wire. It comprizes a Teflon coated hollow wire of a 0.028" wire and a double 0.005" Trilene thread, attached on the one end at already described occluder loop and tied on the other end of the hollow wire.
Trilene is a trademark and identifies a synthetic mono-filament fishing line or thread.
The loading or release hollow wire serves several purposes.
1. It is used to pull the occluder against the septum.
2. It is used to load the occluder-holder by threading the wire through the rubber center of the occluderholder.
3. It is used as the axis of a pushing catheter and the long sheath, so the occluder-holder is pushed and is buttoned securely against the occluder.
4. It is used to release the device, by cutting its distal end, pulling the hollow wire over the double Trilene thread and then pulling the thread as a single strand.
In accordance with the principles of the present invention, the intracardiac prostheses hereof has significant advantages over known devices and specifically the Rashkind device and the King et al '388 device. It is miniaturized in size, requires a 7F(2.3 mm) or 8F(2.7 mm) sheath in comparison to a 15F(5.0 mm) sheath for the Rashkind device or a 23F(7.5 mm) sheath for a King et al device. It does not utilize hooks so it is not traumatic to the endocardium, or the conduction system. It conforms with the overall applicability of this intracardiac device to small children.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1. is a perspective view of the preferred embodiment of the intracardiac prosthesis part of the occluder, illustrated in the unfolded condition.
FIG. 2. is a perspective view of the preferred embodiment of the intracardiac prosthesis part of the occluder, illustrated in the folded condition, ready o be introduced in the long sheath.
FIG. 3. is a perspective view of the occluder connected through the central loop with the loading wire.
FIG. 4. is a perspective view of the intracardiac prosthesis part of the counter-occluder or occluder holder.
FIG. 5. is a cross-sectional view of the intracardiac device part of the occluder, connected to the loading wire and occluding an atrial septal defect.
FIG. 6. is a cross-sectional view of the intracardiac device part of the occluder-holder as it is introduced into the long sheath, over the loading wire.
FIG. 7 is a cross-sectional view of the occluder and occluder-holder parts of the device buttoned together and occluding the atrial septal defect.
FIG. 8. is a cross-sectional view of the detachment of the intracardiac device in the heart and removal of the loading wire and the long sheath.
While this invention is satisfied by embodiments in many forms, will herein be described in detail a preferred embodiment of the invention, with the under