Multi-stage prosthesis

Claim 2

An improved tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first member constituting a flow passage extending along a tube axis and formed of porous polymer, said first member having a first porosity; at least one support bead disposed on an exterior surface of said first member and extending circumferentially at a regular pitch to form spaced apart transverse ridges having a profile protruding above said exterior surface of said first member; and a polymer membrane placed over said support bead and coalesced to said tube said polymer membrane adhering over the ridges and bonding to said first member to enclose said ridges and provide kink and compression resistance without interlaminar peeling, said membrane further modulating said profile to a smooth undulation for atraumatic tunneling and enhanced surgical handling to reduce abrading of surrounding tissue and said membrane having a second porosity that is substantially less than the first member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 3

A tubular prosthesis according to claim 1, wherein said support bead includes a metal wire.

Claim 4

A tubular prosthesis according to claim 1, wherein said support bead is wound with a pitch effective to trap a needle from sliding axially and thereby to prevent tearing along the axis of the tube when the prosthesis is subject to cannulization.

Claim 5

A tubular prosthesis according to claim 1, wherein said support bead is a bead of solid, non-porous and unexpanded PTFE.

Claim 6

A tubular prosthesis according to claim 1, wherein said first tubular member, said support bead and said membrane are coalesced by heat without additional solvent to substantially unitize the prosthesis against delamination.

Claim 7

A tubular prosthesis according to claim 1, wherein said prosthesis has a diameter between one half and forty millimeters.

Claim 8

A tubular prosthesis according to claim 6, wherein said polymer membrane has thickness under 1.0 millimeters.

Claim 9

A tubular prosthesis according to claim 6, wherein said polymer membrane has thickness under two millimeters.

Claim 10

A tubular prosthesis according to claim 6, wherein said first tubular member has a thickness under 0.2 millimeters.

Claim 11

A prosthesis in accordance with claim 1, wherein said porous polymer and said polymer membrane are each fluoropolymer materials.

Claim 12

A tubular prosthesis according to claim 1, wherein said support bead is a polymer coated metal wire.

Claim 13

A tubular prosthesis according to claim 10, wherein said support bead has a diameter between 0.025 and 1.0 millimeter.

Claim 14

A tubular prosthesis in accordance with claim 1, wherein said support element is wound with a pitch effective to direct a needle to a puncture site at an angle which prevents substantial plowing, hole enlarging and shape deformation.

Claim 15

A tubular prosthesis according to claim 1, wherein said support bead is under tension.

Claim 16

A tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first tubular member constituting a flow passage extending along a tube axis and formed of porous polymer, said first tubular member having a first porosity; at least one body of fluoropolymer extending circumferentially about and forming spaced apart transverse ridges disposed on and protruding above an exterior surface of said first tubular member; and a polymer membrane placed over said body and coalesced to said tubular member to provide a continuous undulant cover adhering over the ridges to modulate the external profile of the assembled prosthesis for atraumatic tunneling, and said ridges being dimensioned and positioned with a pitch effective to direct a dialysis needle to a puncture site without substantial ploughing, hole enlargement and shape deformation, whereby the tubular prosthesis heals to surrounding tissue and provides improved dialysis needle access while avoiding tunnel hematomas and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 17

A tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first tubular member constituting a flow passage extending along a tube axis and formed of porous polymer, said first tubular member having a first porosity; at least one body of fluoropolymer extending circumferentially about and forming spaced apart transverse ridges disposed on and protruding above an exterior surface of said first tubular member; and a polymer membrane placed over said body and coalesced to said tubular member to provide a continuous undulant cover adhering over the ridges to modulate the external profile of the assembled prosthesis for atraumatic tunneling, and said ridges being dimensioned and positioned with a pitch effective to direct a dialysis needle to a puncture site without substantial ploughing, hole enlargement and shape deformation, whereby the tubular prosthesis heals to surrounding tissue and provides improved dialysis needle access while avoiding tunnel hematomas and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 18

A tubular prosthesis according to claim 15, wherein said fluoropolymer material has an elastic limit of deformation greater than that of said polymer.

Claim 19

A tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first tubular member constituting a flow passage extending along a tube axis and formed of porous polytetrafluoroethylene (PTFE), said tubular member having a porosity; at least one bead of fluoropolymer extending circumferentially about and forming transverse ridges disposed on and protruding above an exterior surface of said first tubular member at a regular pitch; and a PTFE membrane placed over said bead and coalesced to said first tubular member to provide a continuous undulant cover adhering over the ridges that modulates external profile of the assembled prosthesis to a reduced friction smooth surface profile while enhancing tissue ingrowth at said external profile and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 20

A tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first tubular member constituting a flow passage extending along a tube axis and formed of porous polytetrafluoroethylene (PTFE), said tubular member having a porosity; at least one bead of fluoropolymer extending circumferentially about and forming transverse ridges disposed on and protruding above an exterior surface of said first tubular member at a regular pitch; and a PTFE membrane placed over said bead and coalesced to said first tubular member to provide a continuous undulant cover adhering over the ridges that modulates external profile of the assembled prosthesis to a reduced friction smooth surface profile while enhancing tissue ingrowth at said external profile and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 21

An improved tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first member constituting a flow passage extending along a tube axis and formed of porous polymer, said first member having a porosity; at least one support bead disposed on an exterior surface of said first member and extending circumferentially at a regular pitch to form spaced apart transverse ridges having a profile protruding above said exterior surface of said first member; and a tissue ingrowth membrane placed over said support bead and coalesced to said tube said tissue ingrowth membrane adhering over the ridges and bonding to said first member to enclose said ridges and provide kink and compression resistance without interlaminar peeling, said membrane further modulating said profile for atraumatic tunneling and also promoting fibroblast ingrowth thereby enhancing dialysis needle access of said prosthesis and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.

Claim 22

An improved tubular prosthesis for surgical implantation to replace a segment of a blood vessel, such prosthesis comprising a first member constituting a flow passage extending along a tube axis and formed of porous polymer, said first member having a porosity; at least one support bead disposed on an exterior surface of said first member and extending circumferentially at a regular pitch to form spaced apart transverse ridges having a profile protruding above said exterior surface of said first member; and a tissue ingrowth membrane placed over said support bead and coalesced to said tube said tissue ingrowth membrane adhering over the ridges and bonding to said first member to enclose said ridges and provide kink and compression resistance without interlaminar peeling, said membrane further modulating said profile for atraumatic tunneling and also promoting fibroblast ingrowth thereby enhancing dialysis needle access of said prosthesis and said membrane having a second porosity that is substantially less than the first tubular member to prevent needle punctures from causing premature physical failure of the membrane.