US20060248698A1

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Publication number: US20060248698A1
Application number: US11/122,397
Authority: US
Inventors: Brian Hanson; Wade Johnson; Kenneth Merdan
Original assignee: Individual
Current assignee: Boston Scientific Scimed Inc
Priority date: 2005-05-05
Filing date: 2005-05-05
Publication date: 2006-11-09
Also published as: JP2008539889A; CA2607689A1; WO2006121787A1; EP1901679A1

Abstract

A stent and a method of making a stent from a tubular member. The stent includes a pattern and an opening cut into the wall of the stent and extending from the first end to the second end. One or more connectors may be cut in the tubular wall and extend into the opening cut in the tubular member. The connectors may aid in subsequent expansion and/or forming of the stent.

Description

TECHNICAL FIELD

This invention generally relates to stents and methods of making a stent from a tubular member for placement within a body lumen or interior space of a body during a medical procedure.

BACKGROUND

Stents are expandable endoprosthetic devices adapted to be placed in a body lumen in order to maintain the patency of a body lumen by providing a flow pathway and/or structural support, for example. Stents are typically used in the treatment of atherosclerotic stenosis in blood vessels and the like to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. Additionally, stents may be used in the treatment of aortic aneurysms, by providing strength to a weakened vascular wall. They have also been implanted in other body lumens, such as urinary tracts and bile ducts. Stents are generally tubular structures that may be radially expandable between an unexpanded size and an expanded size greater than the unexpanded size. Therefore, a stent may be inserted through a body lumen in an unexpanded state and then expanded at a specific location within the lumen to an expanded state.

As the use of stents in a variety of medical procedures is gaining widespread acceptance, it is desirable to provide improved methods of manufacturing stents in order to increase efficiency, reduce costs, and/or minimize material waste. The disclosed stents and accompanying methods of manufacturing a stent may be deemed advantageous in view of the increased usage of stents during medical procedures.

SUMMARY

The invention is directed to a stent manufactured from a tubular member. The stent may be cut from a tubular member such that a pattern and an opening extending from the first end to the second end of the tubular member are cut therein. The opening may define a first edge and a second edge through the wall of the tubular member. One or more connectors may be cut along either the first or second edge and may extend into the opening.

Accordingly, a process of making a stent from a tubular member is disclosed. A tubular structure having a pattern configured to provide expansion and an opening defining a first edge and a second edge may be cut from a tubular member. The opening may be cut such that one or more connectors may be cut along either the first or second edge and extend into the opening.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:

FIG. 1A is a perspective view of an exemplary stent within the scope of the invention;

FIG. 1B is a perspective view of an exemplary embodiment of a pattern cut in a tubular member to form a stent within the scope of the invention;

FIG. 1C is a cut away view of the tubular member ofFIG. 1B, more easily showing an opening cut along the tubular member including exemplary connectors within the scope of the invention;

FIG. 1D is a perspective view of the tubular structure formed after expansion of the tubular member ofFIG. 1B;

FIGS. 1E-1F are enlarged views of exemplary embodiments of connectors within the scope of the invention;

FIG. 2A is a perspective view of another exemplary stent within the scope of the invention including a plurality of connectors extending across an opening;

FIG. 2B is a perspective view of an exemplary embodiment of a pattern cut in a tubular member to form a stent within the scope of the invention;

FIG. 2C is a cut away view of the tubular member ofFIG. 2B, more easily showing an opening cut along the tubular member including exemplary connectors within the scope of the invention;

FIG. 2D is an enlarged view of an exemplary connector extending across an opening cut in a tubular member within the scope of the invention;

FIG. 3A is a perspective view of another exemplary stent within the scope of the invention;

FIG. 3B is a perspective view of an exemplary embodiment of a pattern cut in a tubular member to form a stent within the scope of the invention;

FIG. 3C is a cut away view of the tubular member ofFIG. 3B, more easily showing an opening cut along the tubular member including exemplary connectors within the scope of the invention;

FIGS. 3D-3G are enlarged views of exemplary embodiments of connectors comprising tooling nodes within the scope of the invention;

FIG. 4A is a perspective view of an exemplary embodiment of another tubular member to form a stent within the scope of the invention;

FIG. 4B is a cut away view of the tubular member ofFIG. 4A, more easily showing an opening cut along the tubular member including a spine extending along the opening within the scope of the invention;

FIG. 5 is a plan view illustrating an exemplary device for elongating and/or forming the tubular member ofFIG. 3B;

FIG. 6 is a plan view illustrating forming an exemplary stent having overlapping edges within the scope of the invention; and

FIG. 7 is a plan view illustrating forming an exemplary stent having a C-shape within the scope of the invention.

DETAILED DESCRIPTION

As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The detailed description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. The illustrative embodiments depicted are intended only as exemplary. Selected features of any illustrative embodiment may be incorporated into an additional embodiment unless clearly stated to the contrary.

Referring now to the drawings, and particularlyFIG. 1A, illustrates anexemplary stent10 within the scope of the invention. As discussed herein,stent10 may be formed from a tubular member.Stent10 may be manufactured from a variety of materials. For example,stent10 may include a nickel-titanium alloy, such as a shape memory material commonly referred to as nitinol, which may provide thestent10 with superelastic properties, psuedoeleastic properties, or linear elastic properties. Other suitable materials for the stent include, but are not limited to, stainless steels and their alloys, composites, platinum enhanced stainless steel, layered materials, niobium (Nb), zirconium (Zr), Nb—Zr alloys, tantalum (Ta), platinum (Pt), titanium (Ti), gold (Au), silver (Ag), magnesium (Mg), and alloys and compositions comprising the same. Polymers, polymer composites, and combinations and mixtures thereof, may also be used.Stent10 may be treated or coated with an anti-thrombogenic agent, an anti-proliferative agent, an anti-inflammatory agent, or an anti-coagulant. Additionally or alternatively,stent10 may be treated or coated with a medication, such as a time-release drug.Stent10 may also desirably have radiopaque characteristics for visualization on a fluoroscopy device, which may aid in proper placement of thestent10 during a medical procedure. For example,stent10 may be doped with, plated with, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. Some examples of radiopaque materials include, but are not limited to, gold (Au), platinum (Pt), palladium (Pd), tantalum (Ta), tungsten (W), plastic material loaded with radiopaque filler, and the like.Stent10 may, alternatively or additionally, include MRI compatible materials and/or be coated with one or more MRI compatible coatings.

Now referring toFIG. 1B,stent10 may be formed from atubular member50.Tubular member50 may be a thin-walled tube having appropriate dimensions. Apattern60 may be cut intotubular member50. Although a relatively simple pattern of interconnected segments is shown inFIG. 1B, numerous patterns of varying design and complexity are possible. A selectedpattern60 may dictate the degree of expansion and/or flexibility ofstent10.Pattern60 may be cut intotubular member50 by a laser cutting device controlled by a computer automated system, for example a computer numerically controlled (CNC) machine. Such a laser cutting device may be able to replicate a very intricate andprecise pattern60. A laser beam, for example, or a laser beam traveling through a fluid jet may be directed at thetubular member50. Thetubular member50 may be translated and/or rotated relative to the position of the laser, or vise versa, in order to cut the desiredpattern60. Thelumen20 of thetubular member50 may be subjected to a fluid column to flush dross from the tubular member, provide cooling to the cutting zone, and/or deflect the laser beam from the opposing wall of thetubular member50 during the cutting process. The fluid column may be a gas and/or a liquid, and a single or multiple fluid columns may be provided through thelumen20. For example, two fluid columns may be separated by a tubular mandrel disposed within thelumen20 of thetubular member50, such that a first column of fluid is positioned in the annular space between thetubular member50 and the mandrel and a second fluid column is positioned in the lumen of the tubular mandrel. Such a laser cutting process is disclosed in U.S. Pat. No. 6,696,666 entitled Tubular Cutting Process and System, which is herein incorporated by reference in its entirety. Other cutting techniques may include optical etching, chemical etching, electron beam ablation, material deposition, as well as other laser ablation techniques.

FIG. 1C shows a cut away view oftubular member50. Anopening30 may be cut throughtubular member50 during the cutting process or during an additional cutting process.Opening30 may extend from thefirst end22 of thetubular member50 to thesecond end24 of thetubular member50.Opening30 defines afirst edge32 and an opposingsecond edge34 of the wall of thetubular member50 and may extend from thefirst end22 to thesecond end24.

Edges

32,34 may extend from the outer surface to the inner surface of the wall of thetubular member50.Opening30 may extend substantially longitudinally alongtubular member50. However, opening30 may extend helically around thetubular member50, providing a helical configuration of opening30 along the length oftubular member50, undulate along at least a portion of the length oftubular member50, or otherwise extend alongtubular member50 in a regular or irregular manner.

One ormore connectors40 may be cut along thefirst edge32 and extend into theopening30. Additionally or alternatively, one ormore connectors40 may be cut along thesecond edge34 and extend into theopening30.Connectors40 may be positioned adjacent one another and extend from opposing

edges

32,34 of thetubular member50, orconnectors40 may be alternated along at least a portion of the length of theopening30. Aconnector40 may extend from thefirst edge32 toward thesecond edge34 and be attached to aconnector40 extending from thesecond edge34 toward thefirst edge32, thus creating onecontinuous connector40 spanning theopening30 between thefirst edge32 to thesecond edge34. Alternatively, opposingconnectors40 may not be attached to one another, thus a space may remain betweenopposing connectors40.

FIGS. 1E and 1F show two possible embodiments ofconnector40. As shown inFIG. 1E,connector40 may be a serpentine or zig-zag shaped strut extending from thefirst edge32 to thesecond edge34. The shape and size ofconnector40 may be dimensioned such that theconnector40 may be elongated a predetermined amount during a subsequent expansion process.FIG. 1F shows another embodiment of aconnector40 similar to that shown inFIG. 1E.Connector40 may have a serpentine or zig-zag shape having a grasping portion, such as aneyelet42. Theeyelet42 may be substantially located in the central portion of theconnector40, oreyelet42 may be located at any position alongconnector40. An aperture, such ashole44 may extend througheyelet42.Hole44 may allow a tooling device to be coupled or otherwise be engaged with theconnector40.Eyelet42 may be used to retain and/or manipulate thestent10 during a subsequent manufacturing process. The aperture may extend througheyelet42 or the aperture may be a recess or pocket with a terminus within the thickness ofconnector40. Other configurations of connectors, such as connectors with a grasping portion such as tabs, slots, slits, projections, grooves, loops, or hooks are contemplated to be within the scope of the invention.

Referring now toFIG. 1D, thetubular member50 may be expanded subsequent to cutting thepattern60 in thetubular member50. The resultingtubular structure70 may have an outer diameter greater than the initial diameter of thetubular member50.Tubular member50 may be expanded by placing a mandrel through thelumen20 oftubular member50 or by other means for expanding thetubular member50. The expandedtubular structure70 may be amesh65 including a plurality ofinterconnected segments66 formed from the material of thetubular member50 remaining after cutting thepattern60 in thetubular member50. Theinterconnected segments66 are spaced farther apart after expansion to create themesh65 having a plurality ofinterstices67 disposed therein. Thespecific pattern60 cut into thetubular member50 and/or the material used may dictate the degree of expansion of thetubular structure70.

As a result of the expansion of thetubular structure70,connectors40 may become elongated.Connectors40 may provide support and/or continuous structure in order to ensure uniform, non-uniform or an otherwise predetermined expansion of thetubular structure70. Therefore, the tubular shape of thestructure70 may be maintained throughout the expansion process. For example,connectors40 may be configured to have a degree of expansion similar to that of thepattern60. Therefore, the circumferential expansion of thetubular structure70 may be uniform at all locations around the circumference of thetubular structure70.Connectors40 may be configured to provide visual confirmation of proper expansion, such as when theconnectors40 are sufficiently straightened. Therefore, thetubular structure70 may reach its proper expanded dimensions when theconnectors40 have reached a sufficient elongated configuration. Alternatively, connectors may be configured to provide visual confirmation of proper expansion of thetubular member50 at the point where elongation ofconnectors40 commences or at the point of fracture ofconnectors40 fromtubular member50.

Connectors

40 may be sufficiently frangible such thatconnectors40, or a portion thereof, may be separated from thetubular structure70 subsequent expansion of thetubular structure70, orconnectors40 may be retained with thetubular structure70.Connectors40 may be removed during a subsequent process using mechanical, electrical or chemical techniques. A cutting process may be used to provide separation from the

edge

32,34 of thestructure70. For example, a laser ablation technique may be used to separate theconnectors40 from thetubular structure70 or weaken the interface betweenconnector40 andtubular structure70.Connectors40 may be removed by mechanically cutting, snipping, breaking or otherwise severing the connectors, or by grinding, sandblasting or otherwise eroding away material. Additionally or alternatively, a chemical etching or electro-polishing process may be used to removeconnectors40 or a portion thereof.Connectors40 may be dissolved or weakened during a subsequent manufacturing process in which a portion of the material is eroded away.

FIG. 2A shows atubular structure170 forming anotherstent110, similar tostent10.Stent110 may be similarly formed from atubular member150.Tubular structure170, shown inFIG. 2A, includesconnectors140 coupled tostent110 subsequent to expansion of thestent110. However,connectors140 may be removed fromstent110 during or subsequent the expansion process, as discussed herein. Withconnectors140 removed,stent110 may substantially replicatestent10 illustrated inFIG. 1A. As shown inFIG. 2B, apattern160 may be cut throughtubular member150. Additionally, anopening130 may extend from thefirst end122 to thesecond end124 of thetubular member150. As shown in the cut away view inFIG. 2C, theopening130 defines afirst edge132 and asecond edge134 of the wall of thetubular member150. One ormore connectors140 may be cut in thetubular member150 such thatconnector140 extends across the opening130 from thefirst edge132 to thesecond edge134.Connector140, which may more clearly be understood fromFIG. 2D, may be connected to opposing

edges

132,134 of thetubular member150.Connector140 may have one or more apertures, such asholes144 used to retain and/or manipulate thetubular structure170 during a manufacturing process. The aperture may extend through the wall oftubular structure170 or the aperture may be a recess or pocket with a terminus within the wall oftubular structure170. Other configurations of connectors, such as connectors having a grasping portion including tabs, slots, slits, projections, grooves, loops, or hooks are contemplated to be within the scope of the invention.Hole144 may be located in the central portion ofconnector140, orhole144 may be located at another location ofconnector140.Connector140 may provide support and/or continuous structure in order to ensure uniform, non-uniform or otherwise proper expansion of thetubular structure170 during expansion of thestent110. Therefore, the tubular shape of thestructure170 may be maintained throughout the expansion process.Connector140 may allow thetubular structure170 to retain a uniform diameter during expansion of thestent110. The connection between theconnector140 and the

edge

132,134 of thetubular structure170 may be a weakened zone or an otherwise frangible region, such that prior to providing thefinished product stent110,connector140 may be removed. Theconnector140, or a portion thereof, may be removed by mechanically cutting, snipping, breaking, grinding, sandblasting, laser ablation, chemical etching, electro-polishing, or other processes wherein theconnector140 is separated, eroded or dissolved from thetubular structure170.

FIG. 3A illustrates astent210 similar tostent10 in an expanded configuration.Stent210 may include one ormore connectors240, as discussed herein. As shown inFIG. 3B,stent210 may be cut from atubular member250 such as discussed above. Anopening230, which may more easily be shown in the cut away view ofFIG. 3C, may be cut along tubular member during a cutting process and may extend from thefirst end222 to thesecond end224 of thetubular member250. One ormore connectors240 may be cut intubular member250, such thatconnectors240 extend from

edge

232,234 oftubular member250 intoopening230. As more clearly shown inFIGS. 3D-3G,connectors240 may be tooling nodes.Connectors240 may be configured to be coupled to or otherwise engaged with a tooling apparatus.Connectors240 may be used to retain and/or manipulate thetubular structure270 during a subsequent manufacturing process. As shown inFIG. 3D,connectors240 may extend from

edge

232,234 toward an opposing edge. However,connectors240 may not be connected to one another. Instead, a gap may be maintained betweenadjacent connectors240. Althoughconnectors240 are shown adjacent one another, opposingconnectors240 may alternate along the length of thetubular structure270, such as shown inFIG. 3G. Alternatively,connectors240 may extend toward anadjacent connector240 and be connected to anadjacent connector240, as shown inFIG. 3E. The connection betweenadjacent connectors240 may be a weakened zone or an otherwise frangible region. For example, the connection may be a region of reduced cross sectional area or an area scored during a cutting process. Such a configuration ofconnectors240 may be separated during a subsequent manufacturing process. For example,connectors240 may be separated by mechanically cutting, snipping, breaking, grinding, sandblasting, laser ablation, chemical etching, or electro-polishing.FIG. 3F illustrates yet another embodiment ofconnectors240. Astrut242 may bridge a pair ofconnectors240 extending from opposing

edges

232,234 of thetubular structure270.Strut242 may have a serpentine or zig-zag shape or otherwise have an extendable shape. During an expansion process, strut242 may be elongated similar toconnectors40 discussed above regardingFIGS. 1A-1F. Therefore, strut242 may provide support and/or continuous structure around the circumference of thetubular structure270 in order to ensure uniform, non-uniform or otherwise proper expansion of thetubular structure270. Therefore, the tubular shape of thestructure270 may be maintained throughout the expansion process. Elongation of thestrut242 may be a visual indicator of proper expansion of thetubular structure270. Sufficient elongation of thestrut242 may indicate thetubular structure270 has reached its predetermined expanded configuration. Subsequent to expansion of thetubular structure270, strut242 may be removed by mechanical, electrical or chemical means. For example, strut242 may be removed by laser ablation, cutting, snipping, breaking, grinding, sandblasting, or prior to or during a chemical etching or electro-polishing process.

Alternatively or additionally, a wire or filament may be extend betweenconnectors240 to join opposing or alternating connectors. For example, the wire may be laced or threaded throughholes244 ofconnectors240. The wire may be a temporary connector which extends acrossopening230. The wire may substantially restrain separation of opposing

edges

232,234 ortubular structure270. The wire may provide support and/or continuous structure to thetubular member250 to ensure uniform, non-uniform or an otherwise predetermined expansion of thetubular structure270. Therefore, the tubular shape of thestructure270 may be maintained throughout the expansion process. Subsequent expansion and/or forming of thetubular structure270, the wire may be removed from thestructure270. The wire may be removed by mechanical, electrical or chemical means. The wire may be dissolvable whereby it is dissolved with a solvent, by a thermal process, a chemical process or an electrical process. The wire may have characteristics similar to a dissolvable suture. Alternatively, wire may be mechanically removed by a laser, grinding, sandblasting, cutting, snipping, etching, breaking, or by another process.

Additionally or alternatively, connectors, such asconnectors240, having an aperture such as a recess, may include an adhesive. The adhesive, which may be disposed in the recess of theconnector240, may be used to secure one portion of thetubular structure270 with another portion of thetubular structure270. For example, oneconnector240 may be adhesively secured to an opposingconnector240. The adhesive may also be used to secure thetubular structure270 to another apparatus for forming and/or processing of thetubular structure270. The adhesive may be dissolvable, or otherwise provide temporary securement, or the adhesive may be intended to provide permanent securement.

Alternatively or additionally, an apparatus such as a mandrel having hooks, tines, clips, or other engagement means, may be used to engageconnectors240. The mandrel may substantially couple opposing

edges

232,234 such that edges232,234 are restrained from separation during expansion of thetubular structure270. For example, the hooks of the mandrel may be inserted inholes244 ofconnectors240. The mandrel may provide support and/or continuous structure to thetubular member250 to ensure uniform, non-uniform or an otherwise predetermined expansion of thetubular structure270. Therefore, the tubular shape of thestructure270 may be maintained throughout the expansion process. Subsequent expansion and/or forming of thetubular structure270, the mandrel may be removed from thestructure270. Although the mandrel may engageconnectors240, mandrel may also engage another portion of the stent to restrain separation of opposing

edges

232,234.

FIG. 4A shows another embodiment of atubular member350 for forming a stent within the scope of the invention. As more easily shown inFIG. 4B,tubular member350 may be cut with anopening330 extending from afirst end322 to asecond end324. A connectingspine345 may be disposed alongopening330. One ormore connectors340 may extend from

edge

332,334 to connectingspine345. An electrical current of a sufficient magnitude may be applied to the connectingspine345 to remove theconnectors340. Theconnectors340 may be sufficiently thin relative to the other portions of thetubular member350, such that the magnitude of the electrical current and/or the geometry of theconnectors340 is sufficient to remove theconnectors340 from the stent. Alternatively, an electrical current may be directly applied to theconnectors340, thus alleviating the need for the connectingspine345.

Connectors

240, characterized as tooling nodes as shown inFIGS. 3D-3G, may be used to retain and manipulatetubular structure250 during a subsequent process. For example,FIG. 5 illustrates an exemplary process wherein atooling device400 is coupled to or otherwise engaged with one ormore connectors240.Tooling device400 may be manipulated such thattubular member250 is unrolled and/or elongated into a substantiallyplanar sheet280. Thus,interconnected segments266 may be sufficiently directed away from one another to form amesh265 with a plurality ofinterstices267 disposed thereon. While elongated in a substantiallyplanar sheet280, the sheet may be subjected to one or more additional processes, such as a heat treatment process, a cleaning process, a chemical etching process, an electro-polishing process, a quenching process, a coating process, or another chosen process.Sheet280 may undergo a forming process, wherein thesheet280 is rolled into a tubular stent. Additional processes, such as a heat treatment process, a cleaning process, an electro-polishing process and/or a coating process may follow rolling thesheet280 into a tubular stent.Tooling device400, or an additional tooling device, may be used to re-roll or otherwise form thesheet280 into a tubular stent or an intermediate form. For example, a mandrel having clips, tines, hooks or other means of engaging the structure may be used to expand, roll, form, wrap or otherwise manipulate the structure to form a stent.

Any one of the previously disclosed tubular structures may further be rolled into a coil stent. As shown inFIG. 6, a stent, such asstent10 may be wrapped such that thefirst edge32 of thetubular structure70 overlaps thesecond edge34. The degree of overlap may be determined by the profile necessary to provide sufficient clearance through a body lumen, such as a blood vessel, and/or the degree of expansion necessary to provide sufficient patency of a body lumen. A tooling device, such as a mandrel, may be coupled to one ormore connectors40 along one edge ofstent10 and rotated such that thefirst edge32 is urged toward thesecond edge34. Thus thestent10 may be wrapped into a chosen tubular shape such as a coiled overlapping configuration. However,stent10 may be rolled into a coil using other mechanical means. Alternatively,stent10 may be rolled such thatedge32 substantially abutsedge34 to form a generally continuous tubular structure.Edge32 may be secured to edge34 by welding, brazing, soldering, bonding, adhesive, mechanically coupling, crimping, or the like, or edges32,34 may remain unconnected.

Alternatively, one of the previously disclosed tubular structures may be formed in a C-shape such as shown inFIG. 7. Astent10 having a C-shape may be readily expanded within a lumen to provide necessary patency of the lumen. Theopening30 extending along the length of thestent10 allows opposing

edges

32,34 to deflect away from one another whenstent10 is allowed to expand within a lumen.Stent10 may be formed into a C-shape during a subsequent forming/rolling process, or C-shape may be the result of cutting atubular member50 and expanding into atubular structure70 having a longitudinal, helical, undulating or otherwise elongate opening30 as discussed above.

Any one of the previously described stent forming processes may include one or more further processing steps. For example, the tubular member may be subjected to a cleaning process to remove dross or residue subsequent a cutting process. For instance, an alcohol and/or water solution may be used to clean foreign material from the tubular structure. A chemical etching process may be used to remove connectors and/or other material from the tubular structure to provide a surface with no sharp edges or burrs. An electro-polishing process may be used to reduce the surface roughness of the machined tubular member and provide a stent having a substantially smooth outer surface. An electro-polishing process, or similar electrical process, may also be used to dissolve or otherwise separate a connector from the stent. For example, an electro-polishing process may dissolve a percentage of the mass of the material forming the stent. By dimensioning the connectors relatively small compared to the material of the interconnected segments of the stent, the connectors will completely dissolve, erode or otherwise be separated from the stent without fully dissolving the interconnected segments during an electro-polishing process. An electrical current of a sufficient magnitude may be applied to the connectors to separate the connectors from the stent. Additionally, a stent may be subjected to one or more heat treating processes in order to remove residual stresses and/or provide favorable characteristics to the stent, such as shape memory properties.

One illustrative stent forming process may include a plurality of processes. Initially a stent may be laser cut from a tubular member as discussed above. The stent may then be subjected to a chemical etching and/or electro-polishing process to remove residue, connectors and/or rough edges remaining after being cut from the tubular member. Alternatively or additionally, the stent may be placed in an ultrasonic cleaning process. Next, the stent may be expanded or otherwise formed by rolling and/or tucking the ends of the stent. Once formed, the stent may be heat treated to remove any residual stresses and/or provide shape memory properties and then quenched. The stent may then undergo a final cleaning process to remove any remaining residue. Additional processes, such as chemical etching, electro-polishing, cleaning or heat treating, may be included throughout. For example, the stent may be subjected to a chemical etching or electro-polishing process subsequent to being expanded in order to remove temporary connectors from the stent.

It is contemplated that the disclosed process of forming a stent may be substantially used to form other similar products from a tubular member. For example, a filter mesh or frame for an intravenous filter or distal protection device may be formed utilizing the disclosed process.

Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.

Claims

1. A method of forming a stent comprising:

providing a tubular structure having a first end and a second end, a wall surface disposed between the first end and the second end, and a lumen extending longitudinally through the tubular structure from the first end to the second end;

cutting a pattern in the wall surface of the tubular structure, the pattern adapted to allow radial expansion or radial contraction of the tubular structure; and

cutting an opening in the wall surface that extends from the first end to the second end of the tubular structure, the opening defining a first edge and a second edge, each extending from the first end to the second end of the tubular structure on either side of the opening.

2. The method ofclaim 1, wherein the opening extends substantially longitudinally from the first end to the second end of the tubular structure.

3. The method ofclaim 1, wherein the opening extends substantially helically from the first end to the second end of the tubular structure.

4. The method ofclaim 1, wherein the opening extends in an undulating course from the first end to the second end of the tubular structure.

5. The method ofclaim 1, wherein the tubular structure is further processed to form a coiled stent.

6. The method ofclaim 1, wherein the cutting step is performed with a laser.

7. The method ofclaim 1, wherein a connector is cut into the wall surface of the tubular structure and extends from the first edge.

8. The method ofclaim 7, wherein the connector extends into the opening between the first edge and the second edge and connects the first edge to the second edge.

9. The method ofclaim 7, wherein a first connector is cut into the wall surface of the tubular structure at the first edge and a second connector is cut into the wall surface of the tubular structure at the second edge.

10. The method ofclaim 9, wherein the first connector and the second connector are not connected.

11. The method ofclaim 10, wherein the first connector is a tooling node for unrolling, stretching, expanding, handling or rolling the stent.

12. The method ofclaim 10, wherein the second connector is a tooling node for unrolling, stretching, expanding, handling or rolling the stent.

13. The method ofclaim 9, wherein the first connector and the second connector are connected, thereby interrupting the opening extending from the first end to the second end of the tubular structure.

14. The method ofclaim 7, wherein the connector includes an aperture.

15. The method ofclaim 14, wherein the aperture is a hole extending through the connector.

16. The method ofclaim 14, wherein the aperture is a recess in the connector.

17. The method ofclaim 7, wherein the connector is a shape adapted to expand or contract upon expansion or contraction of the tubular structure.

18. The method ofclaim 17, wherein the connector is a serpentine or zig-zag shape.

19. The method ofclaim 18, wherein the connector includes a hole extending through the connector.

20. The method ofclaim 17, wherein the connector is adapted to elongate upon expansion of the tubular structure.

21. The method ofclaim 9, wherein the tubular structure is processed to remove the first connector from the first edge and the second connector from the second edge.

22. The method ofclaim 7, wherein the tubular structure is processed to remove the connector from the first edge.

23. The method ofclaim 7, wherein the tubular structure is processed to form a coiled stent.

24. The method ofclaim 7, wherein the connector is a plurality of tooling nodes, wherein the plurality of tooling nodes are engaged to unroll the tubular structure from a tubular shape to a substantially planar shape for processing.

25. The method ofclaim 7, wherein a wire is laced between the first connector and the second connector.

26. The method ofclaim 1, further comprising a connecting spine extending along the opening, a first connector extending from the first edge to the connecting spine, and a second connector extending from the second edge to the connecting spine.

27. The method ofclaim 26, further comprising applying an electrical current to the connecting spine.

28. A method of forming a stent, comprising:

providing a tubular member having a first end and a second end, a wall surface disposed between the first end and the second end, and a lumen extending longitudinally through the tubular member from the first end to the second end;

cutting a pattern in the wall surface of the tubular member to form a tubular structure, the pattern adapted to allow radial expansion or radial contraction of the tubular structure; wherein the tubular structure includes an opening defining a first edge and a second edge extending from the first end to the second end of the tubular member; wherein the tubular structure further includes a connector extending from the first edge into the opening; and

expanding the tubular structure.

29. The method ofclaim 28, further comprising removing the connector from the tubular structure.

30. The method ofclaim 28, further comprising electro-polishing the tubular structure.

31. The method ofclaim 28, wherein the tubular structure is expanded into a substantially planar sheet.

32. The method ofclaim 28, further comprising wrapping the tubular structure into a coil stent.

33. The method ofclaim 28, wherein the connector includes a tooling node having an aperture.

34. The method ofclaim 33, wherein the aperture is a hole extending through the tooling node.

35. The method ofclaim 33, wherein the aperture is a recess in the tooling node.

36. The method ofclaim 33, further comprising wrapping the tubular structure into a coil stent by gripping the tooling node and wrapping the tooling node toward the second edge.

37. The method ofclaim 36, wherein the tubular structure is wrapped such that the first edge overlaps the second edge.

38. A tubular structure having a pattern provided therein, the pattern adapted to allow radial expansion or contraction of the tubular structure;

the tubular structure having a first end and a second end with a circumferential wall disposed between the first end and the second end and a lumen extending therethrough;

the tubular structure having an opening in the wall extending from the first end to the second end of the tubular structure, the opening defining a first wall edge and a second wall edge extending from the first end to the second end of the tubular structure; and

a connector extending into the opening from the first edge toward the second edge.

39. The tubular structure ofclaim 38, wherein the connector extends from the first edge to the second edge.

40. The tubular structure ofclaim 38, wherein the connector includes an aperture.

41. The tubular structure ofclaim 40, wherein the aperture is a hole extending through the connector.

42. The tubular structure ofclaim 40, wherein the aperture is a recess in the connector.

43. The tubular structure ofclaim 38, wherein a first connector extends into the opening from the first edge and a second connector extends into the opening from the second edge.

44. The tubular structure ofclaim 43, wherein the first connector and the second connector are substantially adjacent each other on opposite sides of the opening.

45. The tubular structure ofclaim 44, wherein the first connector is connected to the second connector to form a strut.

46. The tubular structure ofclaim 45, wherein the strut is a shape adapted to elongate upon expansion of the tubular structure.

47. The tubular structure ofclaim 46, wherein the strut is serpentine or zig-zag shaped.

48. The tubular structure ofclaim 43, wherein the first and second connectors each include an eyelet having a hole extending therethrough.

49. The tubular structure ofclaim 43, wherein the first and second connectors are each a tooling node adapted to be gripped to unroll or expand the tubular structure.

50. The tubular structure ofclaim 43, wherein the first connector overlaps the second connector.