Method of crimping stent on catheter delivery assembly

• US 10,123,894 B2
• Filed: 09/08/2017
• Issued: 11/13/2018
• Est. Priority Date: 01/30/2010
• Status: Active Grant

• Current Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Cardiovascular Systems Incorporated (Abbott Laboratories Incorporated)
• Inventors: Trollsas, Mikael, Ngo, Michael H., Anukhin, Boris, Nikanorov, Alexander, Hossainy, Syed, Papp, John E., Jayasinghe, Dudley, Solter, Zella
• Primary Examiner(s): Cozart, Jermie
• Application Number:
  US15/699,938
• Publication Number:
  US 20170367860A1
• Time in Patent Office: 431 Days
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/844 folded prior to deployment
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/9522 Means for mounting a stent or stent-graft onto or into a placement instrument
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/825 having longitudinal struts
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0004 bioabsorbable
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0096 Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61L 27/00 : Materials for grafts or prostheses or for coating grafts or prostheses dental prostheses A61C13/00; shape or structure of prostheses A61F2/00; use of preparations for artificial teeth A61K6/80; artificial kidneys A61M1/14
• CPC Class Codes: A61L 31/06 : obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: A61L 31/14 : Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: B21D 39/046 : Connecting tubes to tube-like fittings
• CPC Class Codes: B29C 2035/0838 : using laser
• CPC Class Codes: B29C 35/08 : by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29K 2067/046 : PLA, i.e. polylactic acid or polylactide
• CPC Class Codes: B29L 2023/00 : Tubular articles B29L2024/00 takes precedence ; catheters B29L2031/7542
• CPC Class Codes: B29L 2031/7543 : Balloon catheters
• CPC Class Codes: C08L 67/04 : Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 71/02 : Polyalkylene oxides
• CPC Class Codes: Y10T 29/49826 : Assembling or joining
• CPC Class Codes: Y10T 29/4987 : Elastic joining of parts
• CPC Class Codes: Y10T 29/49908 : Joining by deforming
• CPC Class Codes: Y10T 29/49925 : Inward deformation of aperture or hollow body wall
• CPC Class Codes: Y10T 29/49927 : Hollow body is axially joined cup or tube

Abstract

A method of crimping a stent is disclosed. The stent includes a minimum crimped diameter such that in the minimum crimped diameter, a pair of stent rings, between which marker support structures reside, do not make contact with the marker support structures. The crimped profile of the stent of the present invention can be as small as the crimped profile of a same stent but without the maker support structures.

Claims

1. A method of crimping a stent on a catheter delivery assembly, the method comprising:

(a) positioning a polymeric stent over a section of a catheter delivery assembly, wherein the stent comprises;

(i) a set of rings formed by struts connected at crowns, the struts configured to fold and unfold at the crowns, the rings including a proximal end ring, a distal end ring opposing the proximal end ring, and middle rings positioned between the end rings, wherein each ring is associated with its direct neighboring ring by links, and wherein at least one pair of neighboring middle rings can be delineated, via corresponding links there between, into closed cells comprising a W-shaped or W-V-shaped zone included within the closed cell;

(ii) at least one of the links being a marker link, the marker link having a first protrusion off a first side wall of the marker link for holding a first marker and a second protrusion off a second, opposite side wall of the marker link for holding a second marker; and

(iii) wherein the set of rings includes a crimped diameter such that in the crimped diameter, a pair of rings, between which the marker link resides, do not make contact with a perimeter of the first and second protrusions; and

(b) crimping the stent to a crimped diameter on the section of the catheter delivery assembly, wherein the crimping includes heating the polymeric stent to a target temperature, whereby the pair of rings, between which the marker link resides, does not make contact with the perimeter of the first and second protrusions in the crimped diameter.

2. The method of claim 1, wherein the stent is crimped on a balloon of the catheter delivery assembly.

3. A method of crimping a polymer stent on a catheter, the method comprising:

(a) positioning the stent over a balloon of a catheter, wherein the stent comprises a set of longitudinally spaced rings formed by struts connected at crowns, the struts configured to fold and unfold at the crowns, the set of longitudinally spaced rings including a proximal end ring, a distal end ring opposing the proximal end ring, and interior rings positioned between the end rings,

wherein each ring is associated with its direct neighboring ring by links,

at least one of the links of the stent comprises a marker structure for holding a pair of markers,

and the marker structure includes a pair of depots in which the markers are placed, the depots being placed in a planar view along a vertical axis (B-B) perpendicular to a longitudinal axis (A-A) of the stent; and

(b) crimping the stent to the balloon of the catheter,

wherein the stent is crimped to a crimped diameter such that in the crimped diameter, a pair of rings, between which the marker structure resides, does not make contact with the marker structure.

4. The method of claim 3, wherein each link adjoins a pair of the neighboring rings at a crown of each ring, and wherein the crimped diameter is a minimum crimped diameter (MCD) defined by equation 1 or equation 2:

MCD=(Σ

Swi+Σ

Crj+Σ

Lwk)*(1/π

)+2*WT 

 

(equation

     1)

MCD=(Σ

Swi+Σ

Crj+Σ

Lwk)*(1/π

) 

 

(equation

     2),

wherein

Σ

Swi (i=1 . . . n) is the sum of n ring struts having width Swi;

Σ

Crj (j=1 . . . m) is the sum of m crown inner radii having radii Crj (times

     2);

Σ

Lwk (k=1 . . . p) is the sum of p links having width Lwk; and

WT is a ring wall thickness.

5. The method of claim 4, wherein each strut has an aspect ratio (AR) of 0.8 to 1.4, AR being defined as ratio of width to thickness, and wherein optionally each link has an AR of 0.4 to 0.9.

6. The method of claim 5, wherein each link has an AR of 0.4 to 0.9.

7. The method of claim 3, wherein each strut has an aspect ratio (AR) of 0.8 to 1.4, AR being defined as ratio of width to thickness, and wherein optionally each link has an AR of 0.4 to 0.9.

8. The method of claim 7, wherein each link has an AR of 0.4 to 0.9.

9. The method of claim 3, wherein each link adjoins a pair of the neighboring rings at a crown of each ring, and wherein the crimped diameter is less than a minimum crimped diameter (MCD), the minimum crimped diameter (MCD) is defined by equation 1 or equation 2:

MCD=(Σ

Swi+Σ

Crj+Σ

Lwk)*(1/π

)+2*WT 

 

(equation

     1)

MCD=(Σ

Swi+Σ

Crj+Σ

Lwk)*(1/π

) 

 

(equation

     2)

wherein

Σ

Swi (i=1 . . . n) is the sum of n ring struts having width Swi;

Σ

Crj (j=1 . . . m) is the sum of m crown inner radii having radii Crj (times

     2);

Σ

Lwk (k=1 . . . p) is the sum of p links having width Lwk; and

WT is a ring wall thickness.

10. The method of claim 9, wherein each strut has an aspect ratio (AR) of 0.8 to 1.4, AR being defined as ratio of width to thickness, and wherein optionally each link has an AR of 0.4 to 0.9.

11. The method of claim 10, wherein each link has an AR of 0.4 to 0.9.

12. The method of claim 3, wherein the crimping of the stent comprises heating the stent to a temperature between a glass transition temperature and about 10 degrees below a glass transition temperature of the polymer.

13. The method of claim 3, wherein a length of a link having the marker structure is equal to L1+L2, wherein L1 is a length of the links that do not have a marker structure and L2 is the length needed to accommodate the marker structure.

14. The method of claim 3, wherein the crowns have a pre-crimped crown angle of less than 115 degrees.

15. The method of claim 3, wherein the crowns have a pre-crimped crown angle greater than a deployment crown angle.