Partial encapsulation of stents

• US 6,770,087 B2
• Filed: 05/03/2001
• Issued: 08/03/2004
• Est. Priority Date: 02/02/1999
• Status: Expired due to Term

• Current Assignee: Bard Peripheral Vascular Incorporated (Becton, Dickinson & Co)
• Original Assignee: Bard Peripheral Vascular Incorporated (Becton, Dickinson & Co)
• Inventors: Cundy, Sandra, Bebb, Debra, Layne, Richard
• Primary Examiner(s): Pellegrino, Brian E
• Application Number:
  US09/848,740
• Publication Number:
  US 20010032009A1
• Time in Patent Office: 1,188 Days
• Field of Search: 623/1.13, 623/1.27, 623/1.44, 623/1.49, 623/901, 623/921, 604/526, 604/264, 264/510, 264/512
• US Class Current: 623/1.13
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2250/0029 differing in bending or flexure capacity
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device
• CPC Class Codes: Y10T 156/1026 with slitting or removal of material at reshaping area prior to reshaping
• CPC Class Codes: Y10T 156/1056 Perforating lamina
• CPC Class Codes: Y10T 156/1062 Prior to assembly
• CPC Class Codes: Y10T 156/109 Embedding of laminae within face of additional laminae

Abstract

Partially encapsulated stents are made using gaps cut into ePTFE covering material. Ring stents are placed over an inner ePTFE tube (e.g., supported on a mandrel) and are covered by a “lacey” graft sleeve, which is constructed by cutting apertures into an ePTFE tube so that a series of circumferential and longitudinal strips is created. This “lacey” sleeve is then laminated to the inner ePTFE tube to capture the stents. By selecting the size and position of the apertures in the ePTFE covering, it is possible to leave critical parts of the stent unencapsulated to facilitate flexibility and expansion. Alternatively, the gaps can consist of slits cut into the ePTFE covering material. These slits can be cut in any direction including longitudinally, radially, or diagonally. In addition, the slits can be spaced at varying intervals around the covering material to maximize flexibility and expandability. Although a single stent can be used, these approaches lend themselves to use of a plurality of individual ring stents spaced apart along the inner ePTFE tube.

Claims

1. A method for making a partially encapsulated radially expandable reinforced vascular graft, comprising:

providing a first and second tubular expanded polytetrafluoroethylene layer of material, wherein said first tubular layer is a luminal layer of said vascular graft;

creating a plurality of openings in said first and second tubular layers, each of the openings extending through a wall thereof and comprising a longitudinal component and a circumferential component, wherein the length of the longitudinal component is less than the total length of the tubular layer in which it is created, and wherein the length of the circumferential component is less than 360°

;

disposing a radially expandable support layer comprising at least one stent between said first and second tubular layers;

positioning the openings over at least a portion of said support layer; and

attaching said second tubular layer to said first tubular layer.

2. The method of claim 1, wherein said support layer comprises a plurality of ring stents formed in a zigzag pattern of alternating peaks and valleys, wherein the disposing step further comprises disposing the peaks and valleys of successive stents in phase.

3. The method of claim 1, wherein the attaching step further comprises laminating said second tubular layer to said first tubular layer.

4. The method of claim 1, wherein the openings comprise similarly shaped apertures, and wherein the creating step further comprises creating a ring of said apertures at a distinct point along the length of said at least one of said tubular layers.

5. The method of claim 4, wherein the creating step further comprises creating a plurality of rings of apertures along the length of at least one of said layers.

6. The method of claim 5, wherein the apertures are rectangular in shape and wherein each ring is comprised of at least three apertures.

7. The method of claim 1, further comprising the step of positioning said openings in said first tubular layer out of phase with said openings in said second tubular layer.

8. The method of claim 1, further comprising the step of encapsulating completely said support layer at each end of said vascular graft.