Delivery apparatus for a prosthetic valve
A delivery assembly comprises a delivery apparatus and a prosthetic valve releasably connected to a cord-retaining device of the delivery apparatus by a plurality of cords or tethers. The cords desirably have a multi-stranded construction formed from a plurality of strands of material. The multi-stranded construction can be, for example, a braided construction, a twisted construction, or a whip-stitch construction. The multi-stranded construction can include integral openings along opposing end portions of each cord. Each cord can extend through an aperture in an apex of the frame of the prosthetic valve or around an apex with one end portion of the cord being retained on the cord-retaining device and another end portion of the cord being retained on a slideable release member of the delivery apparatus.
1. A prosthetic valve delivery assembly, comprising:
a prosthetic valve comprising an expandable frame having a plurality of apices at one end of the frame; and
a delivery apparatus, comprising:
a cord-retaining device comprising an annular body having an outer surface, the cord retaining device further comprising a plurality of circumferentially spaced tabs extending radially outwardly from the outer surface of the annular body;
one or more slideable release members extending through the cord-retaining device;
a plurality of separate cords, each comprising a first end portion comprising a first loop having a first opening and a second end portion comprising a second loop having a second opening;
a sheath advanceable over the prosthetic valve to retain the prosthetic valve in a radially compressed state, wherein the sheath can be retracted relative to the prosthetic valve to permit radial expansion of the prosthetic valve to a radially expanded state;
wherein each cord extends through an aperture in one of the apices or extends around one of the apices of the frame, wherein the first loop of each cord extends around one of the tabs, and wherein the second end portion of each cord is retained by one of the slideable release members extending through the second opening of the second loop;
wherein the one or more slideable release members can be moved axially relative to the second end portions of the cords to release the second end portions of the cords from the one or more slideable release members, thereby allowing the prosthetic valve to be released from the delivery apparatus.
2. The assembly of claim 1 , wherein the cords have a multi-stranded construction formed from a plurality of strands of material.
3. The assembly of claim 2 , wherein the multi-stranded construction is a braided construction.
4. The assembly of claim 2 , wherein the multi-stranded construction is a twisted construction.
5. The assembly of claim 2 , the multi-stranded construction is a whip stitch construction.
6. The assembly of claim 2 , wherein the plurality of strands of material are made from a polymer.
7. The assembly of claim 6 , wherein the polymer is an ultra-high molecular weight polyethylene.
8. The assembly of claim 2 , wherein the plurality of strands of material are flexible wires.
9. The assembly of claim 1 , wherein each tab comprises a proximal portion spaced radially outward from the outer surface of the annular body, wherein the proximal portion has a radially inwardly facing surface and a radially outward facing surface, wherein a radially extending gap is defined between the radially inward facing surface of the proximal portion of the tab and the outer surface of the annular body, and wherein the first loop extends within the gap.
10. The assembly of claim 1 , wherein the first opening of each cord encircles one of the tabs.
11. A prosthetic valve delivery assembly, comprising:
a prosthetic valve comprising an expandable frame having a plurality of apices at one end of the frame; and
a delivery apparatus comprising;
a cord-retaining device along a distal end portion of the delivery apparatus;
one or more slideable release members extending through the cord-retaining device;
a sheath advanceable over the prosthetic valve to retain the prosthetic valve in a radially compressed state, wherein the sheath can be retracted relative to the prosthetic valve to permit radial expansion of the prosthetic valve to a radially expanded state;
a plurality of separate cords, each cord comprising a first end portion comprising a first loop having a first opening and a second end portion comprising a second loop having a second opening, wherein each cord comprises a multi-stranded construction formed from a plurality of strands of material, wherein the first loop comprises first and second separately braided sections on opposite sides of the first opening, and the second loop comprises first and second separately braided sections on opposite sides of the second opening, wherein the first separately braided section of the first loop comprises a first set of strands of the plurality of strands that are braided together to form a plurality of first picks and the second separately braided section of the first loop comprises a second set of strands of the plurality of strands that are braided together to form a plurality of second picks;
wherein each cord extends through an aperture in one of the apices or extends around one of the apices of the frame with the first loop of the cord retained on the cord-retaining device and the second loop of the cord retained by one of the slideable release members extending through the opening in the second end portion of the cord; and
wherein the one or more slideable release members can be moved axially relative to the second end portions of the cords to release the second end portions of the cords from the one or more slideable release members, thereby allowing the prosthetic valve to be released from the delivery apparatus.
12. The assembly of claim 11 , wherein the cord-retaining device comprises a plurality of tabs and the first end portion of each cord has an opening and is retained on one of the tabs extending through the opening of the first end portion of the cord.
13. The assembly of claim 11 , wherein each cord comprises a fully braided section extending from the first loop to the second loop.
14. The assembly of claim 13 , wherein the plurality of strands of material are braided together along the fully braided section of each cord and each of the first and second separately braided sections of each loop are formed by two or more strands of the plurality of strands.
15. A method for delivering a prosthetic heart valve, comprising:
inserting a distal end portion of a delivery apparatus into the vasculature of a patient, wherein a prosthetic heart valve is retained in a radially compressed state within a sheath of the delivery apparatus along the distal end portion, wherein the prosthetic heart valve has a plurality of apices at one end thereof and is releasably connected to a cord-retaining device of the delivery apparatus by a plurality of separate cords, wherein the cord-retaining device comprises a proximal portion and a distal portion axially spaced from the proximal portion, wherein the delivery apparatus comprises one or more slideable release members extending through the proximal portion and the distal portion of the cord-retaining device, and wherein each cord comprises a first end portion and a second end portion having an opening, wherein each cord comprises a multi-stranded construction formed from a plurality of strands of material, wherein each cord extends through an aperture in one of the apices or extends around one of the apices of the frame with the first end portion of the cord retained on a respective tab of the proximal portion of the cord-retaining device and the second end portion of the cord retained by one of the slideable release members extending through the opening in the second end portion of the cord, wherein the second end portion of each cord is retained on one of the slidable release members at a location between the proximal portion and the distal portion of the cord-retaining device and distal to the first end portion of the cord;
advancing the distal end portion of the delivery apparatus and the prosthetic heart valve through the patient's vasculature to a location at or adjacent a selected implantation location;
retracting the sheath of the delivery apparatus relative to the prosthetic heart valve to deploy the prosthetic heart valve from the sheath; and
wherein deploying the prosthetic heart valve from the sheath allows a distal end of the prosthetic heart valve to radially expand while a proximal end of the prosthetic heart valve remains connected to the cord-retaining device by the cords, such that the distal end of the prosthetic valve expands to a larger diameter than the proximal end of the prosthetic valve.
16. The method of claim 15 , further comprising retracting the one or more slideable release members relative to the cords to release the second end portions of the cords, thereby allowing the prosthetic heart valve to be released from the delivery apparatus.
17. The method of claim 15 , wherein the multi-stranded construction is a braided construction.
18. The method of claim 15 , wherein the first end portion of each cord has a respective opening that receives a protrusion of the cord-retaining device to retain the cord relative to the cord-retaining device.