Longitudinally flexible stent

• US 7,828,835 B2
• Filed: 05/25/2001
• Issued: 11/09/2010
• Est. Priority Date: 03/01/2000
• Status: Expired due to Fees

• Current Assignee: Medinol Limited (Medinol USA Incorporated)
• Original Assignee: Medinol Limited (Medinol USA Incorporated)
• Inventors: Pinchasik, Gregory, Richter, Jacob
• Primary Examiner(s): Bui; Vy Q
• Application Number:
  US09/864,389
• Publication Number:
  US 20020022876A1
• Time in Patent Office: 3,455 Days
• Field of Search: 623/1.11, 623/1.12, 623/1.13, 623/1.14, 623/1.15, 623/1.16, 623/1.17, 623/1.18, 623/1.19, 623/1.2, 623/1.21, 623/1.22, 623/23.58, 623/23.59, 606/108, 606/191, 606/194, 606/195, 606/198
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• 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 2002/91508 the meander having a difference in amplitude along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

An intravascular stent especially suited for implanting in curved arterial portions. The stent retains longitudinal flexibility after expansion. The stent is formed of intertwined meander patterns forming triangular cells. The triangular cells are adapted to provide radial support, and also to provide longitudinal flexibility after expansion. The triangular cells provide increased coverage of a vessel wall. The stent can have different portions adapted to optimize radial support or to optimize longitudinal flexibility. Loops in the stent are disposed and adapted to cooperate so that after expansion of said stent within a curved lumen, the stent is curved and cells on the outside of the curve open in length, but narrow in width whereas cells on the inside of the curve shorten in length but thicken in width to maintain a density of stent element area which much more constant than otherwise between the inside and the outside of the curve. As a result, when the stent is coated with a medicine the more constant density of stent elements results in an even dose being applied to the inside wall of the lumen, avoiding the possibility that a toxic dose be supplied at one area while a less than effective dose is applied to another area.

Claims

1. A coronary stent having a longitudinal axis along the length of the stent comprising:

a. a first loop containing section having loops, said first loop containing section having an axis orthogonal to the longitudinal axis of the stent, the loops in said first loop containing section occurring at a first frequency;

b. a second loop containing section having loops, said second loop containing section having an axis orthogonal to the longitudinal axis of the stent, the loops in said second loop containing section also occurring at said first frequency;

c. said first and second loop containing sections each form a single, continuous, generally sinusoidal pattern around the entire circumference of the stent; and

d. a third loop containing section, said third loop containing section formed of a single, continuous, generally sinusoidal pattern also having an axis orthogonal to the longitudinal axis of the stent, the loops in said third loop containing section occurring at a second frequency that is higher than said first frequency, said third loop containing section disposed in the general circumferential space between each of said first and second loop containing sections to form consecutive repeating patterns along the longitudinal axis of the stent for at least two repetitions and alternately joined to said first and second loop containing sections directly at curved portions of said first, second and third loop containing sections forming a uniform pattern of flexible cells;

e. the loops in said first, second and third loop containing sections being disposed and adapted to cooperate so that, components of said third loop containing section contribute to the cell'"'"'s elongating or shortening when the stent is flexed; and

f. the loops of the first, second, and third loop containing sections further include struts having a thickness in the radial direction and width in the circumferential direction, wherein the struts of the first and second loop containing sections are wider than the width of the struts of the third loop containing section.

2. A stent according to claim 1, wherein the loops in the first loop containing sections are all in phase.

3. A stent according to claim 1, wherein, upon expansion, the cells on the outside of a curved section of the stent narrows as the cells elongate, and cells inside of a curve widen as the cells shorten.

4. A coronary stent comprising:

a. a first circumferential band, formed of a single, continuous, generally sinusoidal pattern of loops at a first frequency having a single axis extending around the entire circumference of the stent;

b. a second circumferential band, formed of a single, continuous, generally sinusoidal pattern of loops, said second band having an axis parallel to the axis of the first band, and said loops occurring at a second frequency higher than said first frequency, said second circumferential band extending in a continuous pattern of loops around the entire circumference of the stent, said first circumferential band alternating with said second circumferential band to form consecutive patterns along the longitudinal axis of the stent for at least two repetitions, said second bands periodically coupled to said first bands directly at curved portions of said first and second circumferential bands to form cells;

c. patterns of loops in said bands being disposed and adapted to cooperate so that second circumferential bands contribute more than first circumferential bands to deformation during flexing of the stent; and

d. the loops of the first, and second bands further include struts having a thickness in the radial direction and width in the circumferential direction, wherein the struts of the first bands are wider than the width of the struts of the second bands.

5. A stent according to claim 4, wherein, upon expansion, the cells on the outside of a curved section of the stent narrows as the cells elongate, and cells inside of a curve widen as the cells shorten.

6. A coronary stent having a longitudinal axis along the length of the stent consisting essentially of in both the unexpanded and expanded state:

a. a first loop containing section, said first loop containing section having an axis perpendicular to the longitudinal axis of the stent, the loops in said first loop containing section occurring at a first frequency;

b. a second loop containing section, said second loop containing section having an axis perpendicular to the longitudinal axis of the stent, the loops in said second loop containing section also occurring at said first frequency, said second loop containing section being 180°

out of phase with said first loop containing section along the longitudinal axis of the stent;

c. at least one of said first and second loop containing sections formed of a single, continuous, generally sinusoidal pattern; and

d. a third loop containing section, said third loop containing section formed of a single, continuous, generally sinusoidal pattern extending in a continuous band of loops around the entire circumference of the stent, the loops in said third loop containing section occurring at a second frequency that is higher than said first frequency, said loops in said third loop containing section having an axis parallel to the axis of the first and second loop containing sections, said third loop containing section disposed in the generally circumferential space between each of said first and second loop containing sections to form consecutively repeating patterns along the longitudinal axis of the stent for at least two repetitions and alternately joined to said first and second loop containing sections, said first, second and third loop containing sections forming a pattern of uniform cells; and

e. the loops of the first, second, and third loop containing sections further include struts having a thickness in the radial direction and width in the circumferential direction, wherein the struts of the first and second loop containing sections are wider than the struts of the third loop containing section.