Modular vascular graft for low profile percutaneous delivery
A hybrid modular endovascular graft wherein a main graft is sized to span at least a portion of a target vessel lesion in a large percentage of patients. Graft extensions may be secured to the main graft to extend the main graft and provide a sealing function for some applications.
1. A modular endovascular graft assembly, comprising:
a bifurcated main graft member formed from a supple graft material including a main fluid flow lumen therein, an ipsilateral leg with an ipsilateral fluid flow lumen in communication with the main fluid flow lumen, a contralateral leg with a contralateral fluid flow lumen in communication with the main fluid flow lumen and a network of inflatable channels disposed on the main graft member including the ipsilateral and contralateral legs which is configured to accept a hardenable fill material to provide structural rigidity to the main graft member when the network of inflatable channels are in an inflated state and which includes at least one inflatable cuff disposed on a proximal portion of the main graft member configured to seal against an inside surface of a patient's vessel;
a proximal anchor member which is formed from a single piece of material, which is disposed at a proximal end of the main graft member, which is secured to the main graft member and which includes a self-expanding proximal stent portion, a self-expanding distal stent portion, and struts that are disposed between adjacent crowns of respective proximal stent portions and distal stent portions, said struts including a cross sectional area that is the same as or greater than a cross sectional area of either proximal stent portions or distal stent portions adjacent each strut and configured to avoid stress and strain concentrations at junctions between the self-expanding distal stent portion and the self-expanding proximal stent portion;
at least one ipsilateral graft extension including a fluid flow lumen disposed therein with the fluid flow lumen of the graft extension sealed to and in fluid communication with the fluid flow lumen of the ipsilateral leg of the main graft member; and
at least one contralateral graft extension including a fluid flow lumen disposed therein with the fluid flow lumen of the graft extension sealed to and in fluid communication with the fluid flow lumen of the contralateral leg of the main graft member.
2. The graft assembly of claim 1 wherein the main graft member has an axial length of about 5 cm to about 10 cm.
3. The graft assembly of claim 2 wherein the main graft member has an axial length of about 6 cm to about 8 cm.
4. The graft assembly of claim 1 wherein the fluid flow lumens of the graft extensions are overlapped with the fluid flow lumens of respective distal legs of the main graft member.
5. The graft assembly of claim 1 wherein the proximal stent of the proximal anchor member further comprises a plurality of barbs having sharp tissue engaging tips that are configured to extend in a radial outward direction in a deployed expanded state.
6. The graft assembly of claim 1 wherein the supple graft material of the main graft and graft extensions comprise layered porous or expanded PTFE.
7. The graft assembly of claim 1 wherein the graft extensions comprise an interposed self-expanding stent disposed between at least one outer layer and at least one inner layer of supple layers of graft material and wherein the interposed stent disposed between the outer layer and inner layer of graft material may be formed from an elongate resilient element helically wound with a plurality of longitudinally spaced turns into an open tubular configuration.
8. The graft assembly of claim 7 wherein the interposed stent is comprised of a superelastic alloy.
9. The graft assembly of claim 8 wherein the superelastic alloy comprises superelastic NiTi alloy.
10. The graft assembly of claim 7 wherein the graft material of each graft extension further comprises at least one axial zone of low permeability.
11. The graft assembly of claim 1 wherein the proximal stent portion of the proximal anchor member comprises a 4 crown stent.
12. The graft assembly of claim 1 wherein the distal stent portion of the proximal anchor member comprises an 8 crown stent.
13. The graft assembly of claim 1 wherein the proximal stent portion and distal stent portion of the proximal anchor member comprise a superelastic alloy.
14. The graft assembly of claim 13 wherein the superelastic alloy comprises superelastic NiTi alloy.
15. A modular endovascular graft assembly, comprising:
a bifurcated main graft member formed from a supple graft material having a main fluid flow lumen therein, an ipsilateral leg with an ipsilateral fluid flow lumen in communication with the main fluid flow lumen, a contralateral leg with a contralateral fluid flow lumen in communication with the main fluid flow lumen and a network of inflatable channels disposed on the main graft member including the ipsilateral and contralateral legs which is configured to accept a hardenable fill material to provide structural rigidity to the main graft member when the network of inflatable channels are in an inflated state and which includes at least one inflatable cuff disposed on a proximal portion of the main graft member configured to seal against an inside surface of a patient's vessel;
a proximal anchor member which is formed from a single piece of material, which is disposed at a proximal end of the main graft member, which is secured to the main graft member and and which includes a self-expanding proximal stent portion, a self-expanding distal stent portion, and struts that are disposed between adjacent crowns of respective proximal stent portions and distal stent portions, said struts having a cross sectional area that is the same as or greater than a cross sectional area of either proximal stent portions or distal stent portions adjacent each strut and configured to avoid stress and strain concentrations at junctions between the self-expanding distal stent portion and the self-expanding proximal stent portion;
at least one ipsilateral graft extension having a fluid flow lumen disposed therein with the fluid flow lumen of the graft extension sealed to and in fluid communication with the fluid flow lumen of the ipsilateral leg of the main graft member; and
at least one contralateral graft extension having a fluid flow lumen disposed therein with the fluid flow lumen of the graft extension sealed to and in fluid communication with the fluid flow lumen of the contralateral leg of the main graft member.
16. A proximal anchor member for anchoring an endovascular graft, comprising:
a monolithic structure formed from a single piece of material;
a self-expanding proximal stent portion;
a self-expanding distal stent portion; and
one or more struts which are disposed between adjacent crowns of respective proximal stent portions and distal stent portions, said one or more struts including a cross sectional area that is the same as or greater than a cross sectional area of either proximal stent portions or distal stent portions adjacent each strut and configured to avoid stress and strain concentrations at junctions between the self-expanding distal stent portion and the self-expanding proximal stent portion.
17. The proximal anchor member of claim 16 wherein the proximal stent portion, distal stent portion and one or more struts comprise a superelastic alloy.
18. The proximal anchor member of claim 17 wherein the superelastic alloy comprises superelastic NiTi alloy.
19. The proximal anchor member of claim 16 wherein the self-expanding proximal stent portion further comprises a plurality of barbs having sharp tissue engaging tips that are configured to extend in a radial outward direction in a deployed expanded state.
20. The proximal anchor member of claim 16 wherein the proximal stent portion comprises a 4 crown stent.
21. The proximal anchor member of claim 16 wherein the distal stent portion of comprises an 8 crown stent.