HYBRID HEART VALVES ADAPTED FOR POST-IMPLANT EXPANSION

• US 20170000603A1
• Filed: 06/30/2016
• Published: 01/05/2017
• Est. Priority Date: 07/02/2015
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Edwards Lifesciences Corporation
• Inventors: Conklin, Brian S., Zeng, Qinggang
• Granted Patent: US 10,695,170 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/2409 Support rings therefor, e.g. for connecting valves to tissue annuloplasty rings A61F2/2442
• CPC Class Codes: A61F 2/2418 Scaffolds therefor, e.g. support stents
• CPC Class Codes: A61F 2/2433 using balloon catheter
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0057 stretchable
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0052 T-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/001 for adjusting a diameter
• CPC Class Codes: A61F 2250/0012 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0021 differing in coefficient of friction
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61F 2250/0048 differing in mechanical expandability, e.g. in mechanical, self- or balloon expandability
• CPC Class Codes: A61F 2250/0089 coded with symbols, e.g. dots, numbers, letters, words

Abstract

A hybrid prosthetic heart valve configured to replace a native heart valve and having a support frame configured to be expanded post implant in order to receive and/or support an expandable prosthetic heart valve therein (a valve-in-valve procedure). The prosthetic heart valve may be configured to have a generally rigid and/or expansion-resistant configuration when initially implanted to replace a native valve (or other prosthetic heart valve), but to assume a generally expanded form when subjected to an outward force such as that provided by a dilation balloon or other mechanical expander. An inflow stent frame is expandable for anchoring the valve in place, and may have an outflow end that is collapsible for delivery and expandable post-implant to facilitate a valve-in-valve procedure.

Claims

1. A hybrid prosthetic heart valve adapted for post-implant expansion and having an inflow end and an outflow end, comprising:

a valve member including an inner structural support stent having upstanding commissure posts extending in the outflow direction alternating with arcuate inflow cusps, and an inflow end undulating up and down corresponding to the commissure posts and cusps, the support stent defining an implant circumference that is non-compressible in normal physiological use and has a first diameter, and wherein the support stent permits expansion from the first diameter to a second diameter larger than the first diameter upon application of an outward dilatory force from within the support stent substantially larger than forces associated with normal physiological use, and a plurality of flexible leaflets attached along the commissure posts and inflow cusps of the support stent and configured to ensure one-way blood flow therethrough; and

a plastically-expandable inflow stent frame secured to and projecting from an inflow end of the support stent and having a strength requiring a predetermined expansion force to convert to an expanded state, and wherein an outflow end of the stent frame undulates with peaks and valleys to at least partially conform to the inflow end of the support stent, and further wherein the outflow end has limited radially compressibility to enable compression of the stent frame during delivery of the heart valve.

2. The prosthetic heart valve of claim 1, further including a biodegradable band disposed concentrically and in close contact with the support stent, the biodegradable band configured to provide resistance to expansion of the support stent after implantation which resistance lessens over time as the band degrades in the body, and wherein the biodegradable band is configured to provide resistance to expansion of the support stent when the predetermined expansion force is applied to the radially-expandable inflow stent.

3. The prosthetic heart valve of claim 1, wherein the support stent includes a radially outer band located concentrically around and attached to a radially inner band having a single one of the expandable segments formed by overlapping free ends located at one of the cusps and separated by a sliding insert, and further including a flexible sleeve surrounding the overlapping free ends of the outer band to maintain alignment of the free ends.

4. The prosthetic heart valve of claim 3, wherein the single expandable segment is located at one of the cusps of support the stent and the inner band is configured to expand below each of the commissure posts when the outer band expands.

5. The prosthetic heart valve of claim 1, further including a unique identifier on the support stent visible from outside the body after implant that identifies the support stent as being expandable.

6. The prosthetic heart valve of claim 1, further including a unique identifier on the stent frame visible from outside the body after implant that identifies the support stent as having an expandable outflow end.

7. A hybrid prosthetic heart valve adapted for post-implant expansion and having an inflow end and an outflow end, comprising:

a valve member including a plurality of flexible leaflets configured to ensure one-way blood flow therethrough and a leaflet support structure defining alternating cusps and commissures to which peripheral edges of the leaflets attach; and

a plastically-expandable inflow stent frame secured to and projecting from an inflow end of the leaflet support structure and having a strength requiring a predetermined expansion force to convert to an expanded state, the stent frame comprising a plurality of expandable struts and an upper edge at an outflow end of the stent frame that undulates with peaks and valleys to at least partially conform to the undulating leaflet support structure, and further wherein the upper edge defines an implant circumference with a nominal diameter that enables physiological functioning of the valve member when implanted, and wherein the upper edge is configured to expand a limited amount from the nominal diameter to an enlarged diameter larger than the nominal diameter upon application of an outward dilatory force from within the outflow end substantially larger than forces associated with normal physiological use.

8. The prosthetic heart valve of claim 7, wherein the stent frame includes a plurality of circumferential row struts connected by a series of spaced axial column struts, and the upper edge comprises an outflow row strut that extends continuously around a periphery of the stent frame and has a series of spaced V-shaped notches that permit limited expansion and contraction.

9. The prosthetic heart valve of claim 8, wherein the outflow row strut has limited radially compressibility of between about 7-20% of the nominal diameter to reduce the size of the outflow end during delivery of the heart valve.

10. The prosthetic heart valve of claim 7, wherein the leaflet support structure comprises an undulating wireform with alternating cusps and commissures, and wherein the outflow edge of the stent frame includes three integrated commissure posts located adjacent to and radially outward from the wireform commissures to which the leaflets attach outside of the wireform.

11. The prosthetic heart valve of claim 10, wherein the integrated commissure posts are separate elements secured with sutures to the stent frame outflow edge.

12. The prosthetic heart valve of claim 10, wherein the integrated commissure posts are integrally formed of the same homogeneous material as the rest of the stent frame.

13. The prosthetic heart valve of claim 7, wherein the stent frame is configured to expand below each of the leaflet support structure commissures upon application of the outward dilatory force.

14. A hybrid prosthetic heart valve adapted for post-implant expansion and having an inflow end and an outflow end, comprising:

a valve member including an undulating wireform with alternating cusps and commissures supporting a plurality of flexible leaflets configured to ensure one-way blood flow therethrough; and

a plastically-expandable inflow stent frame having a radially-expandable inflow end and an outflow end secured to and projecting from an inflow end of the wireform, wherein the outflow end of the stent frame undulates with peaks and valleys corresponding to the wireform, and further wherein the outflow end includes three commissure posts located adjacent to and radially outward from the wireform commissures to which the leaflets attach outside of the wireform, the three commissure posts being secured directly to an upper circumferential row of struts defining a nominal diameter that enables physiological functioning of the valve member when implanted, the upper circumferential row of struts being radially compressible to a smaller contracted diameter to enable compression of the outflow end during delivery of the heart valve, and the upper circumferential row of struts also being radially expandable from the nominal diameter to a larger expanded diameter upon application of an outward dilatory force from within the stent frame substantially larger than forces associated with normal physiological use.

15. The prosthetic heart valve of claim 14, wherein the stent frame is configured to expand below each of the commissure posts upon application of the outward dilatory force.

16. The prosthetic heart valve of claim 14, further including a unique identifier on the stent frame visible from outside the body after implant that identifies the stent frame as having an expandable outflow end.

17. The prosthetic heart valve of claim 14, wherein the stent frame has a series of axial slits below each of the commissure posts that permit expansion of the outflow end upon application of the outward dilatory force.

18. The prosthetic heart valve of claim 14, wherein the stent frame has a series of compression sections including spaces that enable a limited compression of the circumferential structure.

19. The prosthetic heart valve of claim 14, wherein the upper circumferential row of struts extends continuously around a periphery of the stent frame having the peaks and valleys corresponding to the wireform, and the upper circumferential row of struts has a series of spaced V-shaped notches that permit limited expansion and contraction.

20. The prosthetic heart valve of claim 19, wherein the upper circumferential row of struts has limited radially compressibility of between about 7-20% of the nominal diameter to reduce the size of the outflow end during delivery of the heart valve.