Filter apparatus for ostium of left atrial appendage

DETAILED DESCRIPTION The invention provides a filtering membrane that allows blood to pass therethrough while substantially preventing blood clots formed in the atrial appendages from exiting therefrom.
Such clots may cause heart attacks, strokes and other embolic events if allowed to leave the atrial appendage and enter the bloodstream.
The filtering membrane is permanently positioned across the ostium of the atrial appendage by a support structure attached to the filtering membrane.
The filtering membrane filters blood flowing between the atrium and the left atrial appendage and effectively isolates blood clots from leaving the atrial appendage and entering the atrium.
It may be larger than the ostium of the appendage, and extend over an area larger than the appendage ostium.
It is percutaneously delivered to the ostium of the atrial appendage by a catheter and then may be expanded for positioning across or over the ostium and has a means to secure the filtering membrane across or over the ostium.
The filtering membrane itself is permeable to permit blood flow across the membrane.
By allowing the such blood flow across the membrane, the porous structure minimizes any pressure gradient between the atrial appendage and the atrium in a controlled manner.
The porous filtering membrane may eventually become infiltrated with cells.
The permeable filtering membrane allows such tissue growth which may begin along the outer periphery of the structure.
Such tissue growth minimizes uncontrolled leakage about the periphery of the filtering membrane and may assist in attachment of the filtering membrane to the ostium or surrounding tissue.
There are many means for fixing the filtering membrane in position across the ostium of the atrial appendage.
The support structure for the filtering membrane may have a means for self-centering the filtering membrane over the appendage ostium.
The filtering membrane may be glued to the wall of the atrial appendage adjacent the ostium, or the support structure may have wires, barbs, prongs or other methods of fixation which pass through the ostium and extend into or through the atrial appendage and which permanently engage an interior wall thereof