Variable expansion force stent

• US 5,836,966 A
• Filed: 05/22/1997
• Issued: 11/17/1998
• Est. Priority Date: 05/22/1997
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: St. Germain, Jon P.
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US08/861,798
• Time in Patent Office: 544 Days
• Field of Search: 606/198, 606/191, 606/195, 623/1, 623/12
• US Class Current: 606/198
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• 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 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2002/30199 Three-dimensional shapes
• CPC Class Codes: A61F 2002/30322 differing in surface structures
• CPC Class Codes: A61F 2002/30324 differing in thickness
• CPC Class Codes: A61F 2002/30327 differing in diameter
• CPC Class Codes: A61F 2002/821 Ostial stents
• 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 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 2230/0063 Three-dimensional shapes
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0026 differing in surface structures
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A stent having varying outward radial force along its length. In use, the stent can provide greater force in vessel regions requiring greater force and less force in regions requiring less. In particular, more force is provided in the narrowed, center of a stenosis, while not applying too much force to the adjoining healthy tissue area. Greater stent expansion is provided in wider vessel geometries and less stent expansion in narrower regions. Varying force is achieved varying the number of elements, the density of elements, and the thickness of the elements.

Claims

1. A method of stenting a narrowing vessel region, the narrowing region having a wider end and a narrower end, comprising the steps of:

providing a stent having a tubular shaped structure, said structure having a radially outward biased force, said force being varied along said length, said tubular structure having a first end region, a middle region, and a second end region, wherein said force is weakest in said first end region, stronger in said middle region than in said first region, and stronger in said second end region than in said middle region; and

placing the stent in the narrowing region such that the first end region of the stent is disposed toward the narrower end of the narrowing vessel region.