Flexible expandable sheet stent and technology of its manufacturing

• US 6,629,993 B2
• Filed: 04/04/2001
• Issued: 10/07/2003
• Est. Priority Date: 10/04/1998
• Status: Expired due to Fees

• Current Assignee: Brainwave Cardiovascular Technologies Limited
• Original Assignee: Brainwave Cardiovascular Technologies Limited
• Inventors: Voinov, Valarian
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): HO, UYEN T
• Application Number:
  US09/825,639
• Publication Number:
  US 20020002398A1
• Time in Patent Office: 916 Days
• Field of Search: 623/1.15, 623/1-1-, 623/1--, 623/1--, 606/194, 606/195, 606/191
• US Class Current: 623/1.15
• 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 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other

Abstract

A flexible expandable sheet stent is intended for the better support of a diseased vessel wall on the basis of securing the very best characteristics and raising the serviceability of a stent in a vessel. The stent comprises constructive elements, preliminarily formed in the shape of a stencil on the thin sheet metallic blank surface. The stent'"'"'s constructive elements include a saw-shaped profile made of teeth from which the relatively rigid band in the shape of consecutively-united pockets is formed. In a passage formed of consecutively-united pockets, a polymer thread with a fixed length loaded with medical preparations for local drug delivery is deployed. The implantation of the stent in a vessel under X-ray is performed in such a way as to locate the relatively rigid band of consecutively-united pockets on the side of the vessel wall adjoining the cardiac muscle.

Claims

1. A flexible expandable sheet stent for insertion into the lumen of a vessel of a patient, comprising:

constructive elements forming branches, preliminarily formed in a shape of a stencil on a thin sheet metallic blank surface, which shape comprises one relatively rigid band, consisting of consecutively united pockets, the branches of which form periodically repeating twisting closed outlines having longer and shorter sides, whereas the longer side components of each outline are oppositively located in a shape of a relatively free loop, the shape of which is approaching to a circular shape, forming an independent ring with a fastening point on said relatively rigid band,

wherein in said preliminarily formed stencil the constructive elements occupy a primary part of the surface area, excluding that which falls at the stencil openings, radii of formed pockets round-offs and radii of closed free loops short sides round-offs, whereas the width of the openings is executed minimally possible technologically.

2. The flexible expandable sheet stent of claim 1, in which the pockets are formed by a saw-shaped profile bend, a component of the closed free loops outlines, whereas the bend of the pockets is executed into one or alternatively in different sides for an angle of the order of 120°

.

3. The flexible expandable sheet stent of claim 1, wherein a polymer loaded thread of a fixed length is located in the consecutively united pockets.

4. The flexible expandable sheet stent of claim 1, wherein the short sides of the closed free loops are fastened by fragments of a relatively rigid band in a shape of the pockets, whereas in case of stent diameter differentiated in its length according to the different diameters and extent of the afflicted vessel by the fragments of the relatively rigid band in a shape of the said pockets the short sides of the closed free loops are fastened in the place of their transition from one stent diameter to the other.

5. The flexible expandable sheet stent of claim 1, which contains single closed free loops, uniformly distributed along the stent length or in places where increased flexibility is most desirable, including a construction variant with one closed free loop, placed in the middle stent part, whereas the other short sides of the loops are executed in a shape of a relatively rigid band consisting of consecutively united pockets.

6. The flexible expandable sheet stent of claim 5, wherein one closed free loop is positioned approximately midway of the stent and the short sides of the other closed free loops comprise a relatively rigid band of the consecutively united pockets.

7. A method of manufacturing a stent, which comprises the steps of:

(a) separating a thin sheet metallic blank with multiple unwasted quantity of the manufactured stents;

(b) executing a calculated geometrical profile stencil of stent constructive elements on the surface of the thin sheet metallic blank;

(c) shaping consecutively united pockets by bending;

(d) deploying the stencil into a step-by-step gauge fixing the distances among the closed free loops;

(e) introducing cylindrical gauges consecutively into all said loops;

(f) positioning appositively the long sides of the each said loop and trying to achieve the stent minimal diameter necessary for an uninflated balloon;

(g) fixation of the stent on an uninflated balloon of the conductive catheter;

(h) installation and fixation of the polymer loaded thread in a passage formed by the chain of the said consecutively united pockets; and

(i) packing of a ready device.

8. The method of claim 7, wherein steps (e) and (f) are not required.

9. A method of manufacturing a stent, which comprises the steps of:

(a) providing a thin sheet metallic blank;

(b) executing a calculated geometric profile stencil of stent constructive elements on the surface of the thin sheet metallic blank;

(c) bending consecutively united pockets to form a line; and

;

(d) arranging the stencil onto a rigid substantially cylindrical to form fixed distances among closed free loops.

10. The method of claim 9, which comprises the additional step of after step (c) or (d) of inserting a polymer thread into a passage formed by the chain of consecutively united pockets.

11. The method of claim 10, wherein the polymer thread comprises drugs.