Laminated self-sealing vascular access graft
First Claim
1. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
- an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood, wherein the material of the inner tube is the same as the material of the outer tube.
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Accused Products
Abstract
A vascular access graft that is radially supported and self-sealing upon puncture with, for example, a dialysis needle. The graft has at least one access segment that is formed by an inner layer, an intermediate layer, and outer layer. The intermediate layer has, in longitudinal cross-section, regions of different densities. Radial support members within the intermediate layer prevent collapse of vascular access graft and may be formed of a material that has a lower melting temperature than the other components of the graft. A porous or low-density material is provided between the radial support members to permit blood seepage therein, and the graft is formed by heating to cause the radial support members to melt slightly into the interstitial spaces of the low-density material. The radial support members may be individual turns of a helical coil of FEP, and the low-density material may be compressed PTFE “cotton”. The inner and outer layers may also be formed of PTFE. An adhesive layer of FEP may be provided closely surrounding the inner layer to further anchor the various components of the graft during the step of heating. The inner layer extends on either side of the access segment to provide junction segments that can be cleanly trimmed to size, and which can be used for graft cannulation in lieu of the access segment after suitable tissue ingrowth. A method of manufacture of the vascular access graft is also provided.
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Citations
32 Claims
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1. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood, wherein the material of the inner tube is the same as the material of the outer tube. - View Dependent Claims (2, 3, 4)
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5. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood;
wherein the intermediate tubular layer comprises a plurality of axially-spaced radial support members and regions of less dense material that is porous to blood axially interposed between the radial support members, and wherein the radial support members comprise individual turns of a helical coil. - View Dependent Claims (6, 7)
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8. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood;
wherein the intermediate tubular layer includes a thin adhesive layer closely surrounding the inner tube and bonded to the regions of less dense material. - View Dependent Claims (9, 10, 11)
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12. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood, wherein the porous material of the intermediate layer comprises a low-density textile-like material that is longitudinally compressed from a relaxed state of the material.
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13. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood, wherein the low-density textile-like material is made of PTFE.
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14. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an outer tube concentrically disposed about the inner tube; and
an intermediate tubular layer concentrically positioned between the inner and outer tubes, the intermediate tubular layer comprising, in longitudinal cross-section, alternating regions of materials of different densities, one of the materials being porous to blood, wherein the intermediate layer further includes a second material that is substantially non-porous to blood, the low-density textile-like material and second material forming, in longitudinal cross-section, the alternating regions of the vascular access graft, and wherein the vascular access graft is formed by bonding the second material to the low-density textile-like material. - View Dependent Claims (15, 16)
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17. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an intermediate tubular layer having a porosity and concentrically fitted around the inner tube;
a plurality of radial support members concentrically fitted around the intermediate tubular layer; and
an outer tube concentrically disposed about the intermediate tubular layer and radial support members, wherein the plurality of radial support members define axial spaces therebetween, and the intermediate tubular layer is further axially interposed between the radial support members, wherein the radial support members comprise individual turns of a helical coil, wherein the intermediate tubular layer is low-density PTFE and the radial support members are made of a material that has a lower melting temperature that PTFE. - View Dependent Claims (18)
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19. A vascular access graft that can be punctured and will seal about the puncture hole, comprising:
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an inner tube defining an inner lumen of the graft;
an intermediate tubular layer having a porosity and concentrically fitted around the inner tube;
a plurality of radial support members concentrically fitted around the intermediate tubular layer;
an outer tube concentrically disposed about the intermediate tubular layer and radial support members, and a thin adhesive layer closely surrounding the inner tube and bonded to the intermediate tubular layer. - View Dependent Claims (20, 21, 22)
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23. A method of manufacturing a vascular access graft, comprising:
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placing an inner layer on a mandrel;
positioning a tube of low-density material over the inner layer, the tube having a first density;
compressing the tube of low-density material to a second density higher than the first density;
providing a plurality of axially spaced radial support members over the compressed tube of low-density material;
closely surrounding the assembly of the tube of low-density material and radial support members with an outer tubular layer;
bonding the aforementioned components of the vascular access graft; and
removing the mandrel. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32)
longitudinally compressing the tube of low-density material to a second length shorter than the first length.
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31. A product, produced by the method of claim 30.
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32. A product, produced by the method of claim 23.
Specification