Compressed tissue for heart valve leaflets
First Claim
1. A method of manufacturing an improved leaflet for a minimally invasive heart valve, comprising:
- providing a substantially flat sheet formed entirely of pericardial tissue and having a starting thickness, the sheet having opposite first and second surfaces;
placing the sheet of pericardial tissue on a first substrate such that the first surface of the pericardial tissue contacts the first substrate;
displacing a second substrate such that it contacts the second surface of the pericardial tissue;
applying a compressive force to the sheet of pericardial tissue to reduce the thickness of the pericardial tissue by at least about 10% to a reduced thickness without substantially reducing an absolute tensile strength of the pericardial tissue; and
cutting at least one heart valve leaflet from the compressed sheet of pericardial tissue, the reduced thickness leaflet being configured for use with a minimally invasive heart valve.
1 Assignment
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Accused Products
Abstract
A process and system for compressing bioprosthetic tissue for use in medical implants. The process involves placing the tissue between two compressive surfaces and applying a force to reduce any nonuniformity of thickness in the tissue, while at the same time reduce the overall thickness. One particularly useful application is the compression of bioprosthetic sheet during the preparation of heart valve leaflets. Bovine pericardium may be compressed to reduce its thickness by about 50%, and then formed into heart valve leaflets. The thinned leaflets have substantially the same absolute strength as those made from uncompressed tissue, and are particular desirable for use in minimally invasive valves which must be compressed into a small profile. The thin tissue enables a reduction in the overall size of the minimally invasive heart valve for delivery. For instance, rolled MIS valves may be reduced in size to as small as 20 mm in diameter. Desirably, a cross-linking step is combined with the compression step to fix the reduced thickness of the tissue. One apparatus may include porous compression substrates through which a cross-linking solution may diffuse so as to perform the fixation and compression simultaneously.
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Citations
5 Claims
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1. A method of manufacturing an improved leaflet for a minimally invasive heart valve, comprising:
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providing a substantially flat sheet formed entirely of pericardial tissue and having a starting thickness, the sheet having opposite first and second surfaces; placing the sheet of pericardial tissue on a first substrate such that the first surface of the pericardial tissue contacts the first substrate; displacing a second substrate such that it contacts the second surface of the pericardial tissue; applying a compressive force to the sheet of pericardial tissue to reduce the thickness of the pericardial tissue by at least about 10% to a reduced thickness without substantially reducing an absolute tensile strength of the pericardial tissue; and cutting at least one heart valve leaflet from the compressed sheet of pericardial tissue, the reduced thickness leaflet being configured for use with a minimally invasive heart valve. - View Dependent Claims (2, 3, 4, 5)
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Specification