5,992,000
`[11] Patent Number:
`[19]
`United States Patent
`
`Humphrey et al.
`[45] Date of Patent:
`Nov. 30, 1999
`
`U5005992000A
`
`[54]
`
`STENT CRIMPER
`
`[75]
`
`Inventors: John W. Humphrey, Eden Prairie;
`Terry v_ Brown, Fridley; Charles L.
`-
`.
`Euteneuerf St‘ Mphfld’ Nam H'.
`Hoang, Minneapolis, Leo M. Kllsch,
`,
`Maple Grow; Chmtol’her R- Larsom
`St Paul; Jonalhan C- SelL We“ 5L
`Paul, all of Minn; Vladimir R-
`Tsukernik, West Roxbury, Mass.;
`Lawrence W. Ulanowski, Brooklyn
`Park, Minn.
`
`[73] ASSlgHCCI SciMed Life Systems, IIIC., Maple
`Grove, Mlnn.
`
`[21] Appl' NO': 08/951’550
`[22]
`Filed:
`Oct. 16, 1997
`
`Int. Cl.6 ..................................................... B21D 39/00
`[51]
`[52] U.S. Cl.
`............................... 29/516; 29/282; 29/283.5
`[58] Field of Search .............................. 29/282, 423, 516,
`29/517, 234, 235, 283, 283.5; 606/1, 108,
`198; 623/1
`
`[56]
`
`References Cited
`
`US. PATENT DOCUMENTS
`3133; Eurton 6t a1~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 62%1/23
`immermans
`......
`
`3/1994 Inoue ...................................... 606/191
`8/1994 Conrelius et al.
`........................ 604/96
`.
`8/1995 Williams et a1.
`..... 29/235
`
`
`4/1996 Herrero ................... 29/282
`
`8/1996 Wllllams et a1.
`.
`~~ 29/407
`
`“1997 Susawa 6t a1~
`623/1
`2133; gfittiyea lLI""""
`2831(9);
`ev in e a .
`5/1997 Verbeek ........
`606/198
`9/1997 Verbeek
`606/1
`12/1997 Myers et a1.
`................................ 623/1
`
`
`
`gagégaggg
`,
`,
`5,290,305
`5,338,295
`5,437,083
`5,509,184
`5,546,646
`595917222
`5,2229%):
`,
`,
`5,630,830
`5,672,169
`5,700,285
`
`3/1998 Penner et al.
`............................... 606/1
`5,725,519
`4/1998 Pinchuck ............... 606/1
`5,736,251
`
`~~~~~ 606/1
`4/1998 Williams et a1~
`5,738,674
`3133: Erin ettal.1 ............................ 602/2139:
`3,323,334
`..............................
`e
`er e a.
`,
`,
`6/1998 Imran et a1.
`..... 606/198
`5,766,203
`
`9
`5 810 871
`/1998 Tuckey et al.
`..... 606/198
`,
`,
`
`9/1998 Morales ............ 606/198
`5,810,873
`
`
`5,836,952 11/1998 Davis
`..... 606/108
`......................................... 606/1
`5,860,966
`1/1999 Tower
`5,893,852
`4/1999 Morales .
`.
`5,893,867
`4/1999 Bagaoisan et al.
`FOREIGN PATENT DOCUMENTS
`
`0 630 623 A2 12/1994 European Pat. Off .
`0 701 800
`3/1996 European Pat. Off.
`.
`295 06 654
`7/1995 Germany ...................... A61M 29/00
`195 32 2:13
`3/1997 G
`A61M 29/00
`WO 96/03092
`A1
`2/1996 WIPO ............................... A61F 2/02
`
`WO 97/20593
`9/1997 WIPO .....
`A61M 29/00
`WO 98/19633
`5/1998 WIPO ............................... A61F 2/06
`
`ermany ......................
`
`OTHER PUBLICATIONS
`Derwent Abstract Accession No.
`93—135787/199317,
`abstract of DE 4235004, 1993.
`
`irimary @Caminer—fi. TthEas gughes
`sszstant xammer— ermie
`.
`ozart
`Attorney, Agent, or Firm—Vidas, Arrett & Steinkraus
`[57]
`ABSTRACT
`
`An apparatus for crimping a stent to a catheter as well as a
`method for crimping a stent to a catheter are disclosed in
`several embodiments. The apparatus in its various embodi-
`ments involves the application of a uniform radially inward
`force to a compressible tube in which the stent and catheter
`-
`are Slmated‘
`
`21 Claims, 9 Drawing Sheets
`
`740
`
`726
`
`M 734
`
`
`700
`S
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`
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`....‘:;rf.:‘.‘“}.-l‘;;;‘
`750
`
`726
`7! 2
`
`
`722
`
`704
`
`7l0
`
`720
`
`702
`
`707
`
`Edwards Lifesciences v. Boston Scientific
`
`
`
`US. Patent N 0. 6,915,560
`IPR2017-00444 EX. 2027
`
`Page 1 of 19
`
`Page 1 of 19
`
`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`Nov. 30, 1999
`
`Sheet 1 of 9
`Sheet 1 0f 9
`
`5,992,000
`5,992,000
`
`
`
`
`
`Page 2 of 19
`
`Page 2 of 19
`
`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`N0V.30, 1999
`
`Sheet 2 of 9
`Sheet 2 0f 9
`
`5,992,000
`5,992,000
`
`
`
`
`
`Page 3 of 19
`
`Page 3 of 19
`
`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`N0V.30, 1999
`
`Sheet 3 of 9
`Sheet 3 0f 9
`
`5,992,000
`5,992,000
`
`Fig. 5
`
`
`
`52
`I52
`
`
`
`
`
`Page 4 of 19
`
`Page 4 of 19
`
`

`

`US. Patent
`
`N0V.30, 1999
`
`Sheet 4 0f 9
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`5,992,000
`
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`Page 5 of 19
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`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`N0V.30, 1999
`
`Sheet 5 of 9
`Sheet 5 0f 9
`
`5,992,000
`5,992,000
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`Page 6 of 19
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`Page 6 of 19
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`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`Nov. 30, 1999
`
`Sheet 6 of 9
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`Page 7 of 19
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`Page 7 of 19
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`US. Patent
`
`Nov. 30, 1999
`
`Sheet 7 0f 9
`
`5,992,000
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`Page 8 of 19
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`Page 8 of 19
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`

`

`U.S. Patent
`
`
`
`Nov.30, 1999
`
`Fig. 14
`
`Sheet 8 of 9
`
`5,992,000
`
`Fig. 16a
`6b. 7762 /766
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`
`Page 9 of 19
`
`

`

`U.S. Patent
`US. Patent
`
`Nov.30, 1999
`N0V.30, 1999
`
`Sheet 9 of 9
`Sheet 9 0f 9
`
`5,992,000
`5,992,000
`
`
`
`
`
`Page100f19
`
`Page 10 of 19
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`

`

`1
`STENT CRIMPER
`
`2
`SUMMARY OF THE INVENTION
`
`5,992,000
`
`BACKGROUND OF THE INVENTION
`
`This invention relates to an assembly and a method for
`fastening a stent onto a catheter. This kind of device finds
`routine use in the area of percutaneous transluminal coro-
`nary angioplasty (PTCA) procedures, although it may be
`used in other types of procedures, as well.
`Stents and stent delivery assemblies are utilized in a
`number of medical procedures and situations, and as such
`their structure and function are well known. A stent is a
`
`generally cylindrical prosthesis introduced via a catheter
`into a lumen of a body vessel in a configuration having a
`generally reduced diameter and then expanded to the diam-
`eter of the vessel. In its expanded configuration, the stent
`supports and reinforces the vessel walls while maintaining
`the vessel in an open, unobstructed condition.
`Inflation expandable stents are well known and widely
`available in a variety of designs and configurations. Inflation
`expandable stents are crimped to their reduced diameter
`about the delivery catheter, then maneuvered to the deploy-
`ment site and expanded to the vessel diameter by fluid
`inflation of a balloon positioned between the stent and the
`delivery catheter. The present invention is particularly con-
`cerned with the crimping of inflation expandable stents
`although self-expanding stent may be used as well.
`An example is the stent described in PCT Application NO.
`960 3092 A1, published Feb. 8, 1996, the content of which
`is incorporated herein by reference.
`In advancing an inflation expandable balloon through a
`body vessel to the deployment site, the stent must be able to
`securely maintain its axial position on the delivery catheter,
`without translocating proximally or distally, and especially
`without becoming separated from the catheter. Stents that
`are not properly secured or retained to the catheter may slip
`and either be lost or be deployed in the wrong location. The
`stent must be crimped in such a way as to minimize or
`prevent altogether distortion of the stent and to thereby
`prevent abrasion and/or reduce trauma of the vessel walls.
`In the past, this crimping has been done by hand resulting
`in non-uniform crimps due to the application of uneven
`force to the stent. Anon-uniformly crimped stent must either
`be discarded or re-crimped. Stents which have been crimped
`multiple times can suffer from fatigue. Moreover, a non-
`uniform crimping can result in scoring or other marking of
`the stent which can cause thrombosis. A poorly crimped
`stent can also damage the underlying balloon. Other meth-
`ods of crimping stents include the use of mechanical devices
`such as those disclosed in US. Pat. No. 5,546,646 to
`Williams et al, US. Pat. No. 5,183,085 to Timmermans et
`al., US. Pat. No. 5,626,604 to Cottone, Jr. and WO
`97/20593.
`
`It is a goal of the present invention to produce a device,
`optionally portable,
`to crimp a stent onto a catheter uni-
`formly while minimizing the distortion of and scoring and
`marking of the stent and due to the crimping. This goal is
`accomplished in the present invention in its many embodi-
`ments by applying a uniform force to a compressible tube in
`which the stent and catheter are situated.
`
`In the description that follows it is understood that the
`invention contemplates crimping a stent to a catheter with an
`expandable region. Thus, when reference is made to crimp-
`ing a stent to a catheter, a balloon may be situated between
`the stent and the catheter,or the stent may be crimped to a
`region of a catheter having some other means for expanding.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`The present invention provides an apparatus for com-
`pressing a stent onto a catheter,
`the catheter preferably
`including are expandable portions such as a balloon under
`the stent. The apparatus comprises a retaining means for
`preventing the stent from sliding along the catheter and a
`crimping means for applying a substantially uniform, cir-
`cumferential radial inward force to at least a portion of the
`stent. The crimping means moves longitudinally with
`respect to the stent and over it to apply a substantially
`uniform circumferential radial inward crimping force to the
`stent.
`
`In one embodiment, the retaining means comprises a peel
`away tube mounted coaxially on the catheter adjacent to the
`proximal of the stent. In another embodiment, the retaining
`means comprises deformable tubing mounted coaxially on
`the catheter over the stent. The deformable tubing has a first
`diameter prior to stretching and a second smaller diameter
`after stretching. The deformable tubing grips the uncrimped
`stent and holds it in place upon being stretched.
`In another embodiment, the crimping means comprises a
`tapered peel away tube mounted coaxially on the catheter
`adjacent to the distal end of the stent. The tapered peel away
`tube has a first diameter larger than the diameter of the stent
`and a second diameter smaller than the diameter of the
`
`uncrimped stent. The uniform circumferential radial inward
`force is applied by sliding the tapered peel away tube over
`the stent.
`
`In another embodiment, the crimping means comprises a
`die having a bore. The diameter of the bore is smaller than
`the diameter of the stent. The uniform radial inward force is
`
`applied by introducing the stent into the bore and sliding the
`die over the stent.
`
`The present invention in another embodiment provides an
`apparatus for compressing a stent comprising a tube having
`a first end and a second end, the tube preferably having a
`longitudinal axis coincident with the longitudinal axis of the
`apparatus, the tube characterized by a first diameter in the
`absence of tension and a second smaller diameter when
`
`longitudinal tension is provided on the tube, the tube receiv-
`ing a catheter and a stent to be crimped to said catheter, said
`stent having an initial diameter prior to being crimped and
`a final diameter after being crimped and a die having a bore
`sized to crimp the stent, the longitudinal axis of the bore
`coincident with the longitudinal axis of the tube, the tube at
`least partially resting within the bore of the die. The stent is
`crimped to the catheter with the above device by providing
`tension to the tube thereby reducing its diameter and causing
`it to grip the stent and sliding the die along the tube and over
`the stent. The invention further comprises a slide means to
`which the die is mounted to facilitate sliding the die over the
`stent.
`
`In another embodiment of the invention, an apparatus for
`compressing a stent is disclosed comprising a deformable
`tube and tension applying means for applying longitudinal
`tension to the deformable tube. The deformable tube, fas-
`tened to the tension applying means is characterized by a
`first diameter in the absence of tension and a second smaller
`
`diameter when longitudinal tension is provided on the tube.
`Astent is crimped onto a catheter using the above-described
`apparatus by applying longitudinal tension via the tension
`applying means to the deformable tube whereby the diam-
`eter of the deformable tube decreases as the tube is stretched,
`thereby crimping the stent.
`In another embodiment, the present invention is directed
`to a method of crimping a stent onto a catheter. The method
`
`Page110f19
`
`Page 11 of 19
`
`

`

`5,992,000
`
`3
`comprises placing a stent coaxially on stent bearing region
`of the catheter, placing a stent retaining means on the
`catheter, applying a stent crimping means, the means being
`capable of applying a uniform radial inward force to at least
`a portion of the stent, to the stent and removing the stent
`crimping means and stent retaining means. The stent reten-
`tion means may comprises a peel away tube mounted
`adjacent to the stent or may comprise a deformable tube, the
`diameter of the tube reducing on stretching, which is placed
`over the stent and stretched. The stent crimping means may
`comprise a tapered tube slidably mounted coaxially over the
`catheter, the tube having first and second ends, the first end
`having a larger diameter than the stent and the second end
`having a smaller diameter than the stent. In use, the stent
`crimping means is applied by sliding it over the stent.
`In yet another embodiment,
`the present
`invention is
`directed to a method for affixing a stent onto a catheter. The
`method involves placing a stent coaxially on the stent
`bearing region of the catheter and optionally placing a peel
`away tube coaxially on the stent bearing region of the
`catheter. The first end of a tapered, optionally peel-away
`sheath having first and second ends, the first end having a
`larger diameter than the second end, is placed coaxially over
`a part of the peel away tube. The peel-away tube and stent
`and catheter therein is slidably moved through the tapered
`peel away sheath until the stent is crimped onto the catheter.
`Thereafter, the peel-away sheath is peeled away, as is the
`optional peel-away tube.
`invention is
`the present
`In yet another embodiment,
`directed to an apparatus for crimping a stent comprising a
`catheter, the catheter having a stent bearing region and a
`stent mounted thereon and, optionally, a balloon mounted at
`least partially underneath the stent. The apparatus further
`comprises a peel away tube mounted coaxially on the
`catheter adjacent to one end of the stent, the peel away tube
`serving as a stop to prevent sliding of the stent during
`crimping. The apparatus further comprises a tapered peel
`away tube surrounding the catheter at the second end of the
`stent. The diameter of the first end of the tapered peel away
`tube exceeds the diameter of the uncrimped stent while the
`diameter of the second end of the tapered peel away tube is
`less than the diameter of the uncrimped stent.
`invention is
`In yet another embodiment,
`the present
`directed to an apparatus for crimping a stent comprising a
`tubular plunger having a first end and a second end, the
`plunger having an inner diameter exceeding the diameter of
`the stent prior to crimping, a deformable inner tube for
`receiving the stent and catheter from the plunger, the inner
`tube fixedly attached to the second end of the tubular
`plunger, the deformable inner tube having a first end and a
`second end, an outer tube, the outer tube having a first and
`a second end, the outer tube notched at the second end so as
`to have a plurality of oppositely situated wall sections at the
`second end, the second end of the plunger slidably mounted
`in the first end of the outer tube and the deformable inner
`
`tube residing within the outer tube, a die slidably mounted
`on the outer tube, the die comprising an outer housing and
`an inner housing, the outer housing in communication with
`the inner housing, the inner housing having an inner bore
`therethrough, the inner bore having a circular cross-section
`at every point along the length of the inner bore, the bore
`characterized by a minimum diameter, the diameter of the
`stent prior to crimping exceeding the minimum diameter of
`the bore, a portion of the inner tube traversing the bore, the
`die further having one or more slots therethrough between
`the inner housing and the outer housing, the slots arranged
`so as to receive the plurality of oppositely situated wall
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`sections in sliding engagement and an end portion, the end
`portion residing at the second end of the outer tube, the end
`portion optionally having a hole therein from which the
`catheter may emanate. The stent is crimped to the catheter by
`inserting the stent and catheter through the plunger and into
`the inner tube, and sliding the die along the outer tube such
`that the die passes over the stent and applies a uniform radial
`inward force to the stent.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`FIG. 1 shows a side view of one embodiment of the
`
`present invention;
`FIG. 2 shows a side view of a braid element used in the
`invention;
`FIG. 3 show a perspective view of a die moving over a
`stent or a catheter;
`FIG. 4 shows a perspective view of another embodiment
`of the present invention including a mounting apparatus;
`FIG. 5 shows a side view of another embodiment of the
`
`present invention including a mounting apparatus;
`FIG. 6 shows a side view of another embodiment of the
`
`present invention;
`FIG. 7 shows a side view of another embodiment of the
`
`present invention;
`FIG. 8 shows a side view of another embodiment of the
`
`present invention;
`FIG. 9 shows a side view of another embodiment of the
`
`present invention;
`FIG. 10a shows a side view of another embodiment of the
`
`present invention;
`FIGS. 10b and 10c show a side view of a stent in the
`
`process of being crimped in the stent crimper depicted in
`FIG. 10a;
`FIG. 11a is a side elevational view sectioned vertically
`along the longitudinal axis of yet another embodiment of the
`invention;
`FIG. 11b shows the stent crimper of FIG. 11a absent the
`catheter and with an optional mandrel present.
`FIG. 12 is a detailed fragmentary view of the outer tube
`depicted in FIG. 11 showing the notched end of the outer
`tube.
`
`FIG. 13 is an enlarged fragmentary section taken from the
`area bracketed by 13 in FIG. 11 showing the die of FIG. 11
`in detail;
`FIG. 14 is a detailed perspective view of the die depicted
`in FIG. 11;
`FIG. 15 is a detailed sectional view of another embodi-
`ment of a die;
`FIG. 16a is a detailed perspective view of an outer tube
`used with the die of FIG. 15;
`FIG. 16b is a detailed cross sectional view of the outer
`
`tube of FIG. 16a taken along line 16b—16b.
`FIG. 17 is a detailed cross sectional view of another die
`useful in the invention, and
`FIG. 18 is a perspective schematic showing of yet another
`embodiment of the invention.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The present invention provides an apparatus for com-
`pressing a stent onto a catheter. In a preferred embodiment
`the catheter includes an expansive means, such as a balloon
`
`Page120f19
`
`Page 12 of 19
`
`

`

`5,992,000
`
`5
`over which the stent is crimped. The apparatus comprises a
`retaining means for preventing the stent from sliding along
`the catheter and a crimping means for applying a substan-
`tially uniform, circumferential radial inward force to at least
`a portion of the stent. The crimping means moves longitu-
`dinally with respect to the stent and catheter
`As shown in FIG. 1, all embodiments of the apparatus for
`crimping a stent include an optional tube 10 having a first
`end 14 and a second end 18. The tube may serve as a
`retaining means to prevent the stent from sliding along the
`catheter. Tube 10 is characterized by a first diameter in the
`absence of tension and a second smaller diameter when
`
`tension is provided on the tube. While the
`longitudinal
`interior of the tube has a round cross-section, the exterior
`need not be round. Optionally, tube 10 has a longitudinal
`axis coincident with the longitudinal axis of the apparatus.
`Tube 10 receives a catheter 22 (shown with a balloon 24
`thereon) and a stent 26 over the catheter and balloons to be
`crimped to said catheter, the stent having an initial diameter
`prior to being crimped and a final smaller diameter after
`being crimped. The tube also helps to prevent or minimize
`the elongation of the stent during the crimping process and
`protects the stent.
`that exhibits a
`Tube 10 may comprise any material
`reduced diameter upon the application of tension thereto and
`that has a relatively smooth interior surface to avoid
`marking, scoring or otherwise damaging the stent. The tube
`may be made of any material that is softer than the die used
`to crimp the stent, that won’t stick to the stent and that won’t
`damage the stent, including polymers. One such material is
`polyester. However, materials such as tefion, polyethylene,
`polyurethane and nylon may also be used. Additionally, the
`tube, having an interior surface and an exterior surface, may
`be made of a lubricious material or have a lubricious coating
`thereon. One surface of the tube may be more lubricious
`than the other. Preferably, the tube will be transparent or
`translucent so as to facilitate the viewing of the stent position
`therein. The tube must be round on the inside, but need be
`round on the outside.
`
`The tube may comprise a polymer braid as illustrated at
`32 and in FIG. 2. Individual strands 33 of a given polymer
`are interwoven as shown in FIG. 2 to form tubular braid 32.
`
`The polymer strands must be thick enough to provide
`structural integrity to the tube but not so thick as to prevent
`elongation of the tube and the associated constriction upon
`elongation. Moreover, the weave must be dense enough as
`to prevent parts of the stent, depending on the design of the
`stent, from penetrating the weave and becoming enmeshed
`in it. In a preferred embodiment, individual strands 33 made
`of polyester having a circular cross section of diameter 5/1000
`inch. Strands 32 are woven together in a clothing weave to
`form tubular braid 32 with the weave being about 20 to
`about 90 picks/inch, desirably about 32 picks/inch. The
`braid tube described is manufactured by SCIMED Life
`Systems, Inc., Maple Grove, Minn. and/or SantaFe Textiles,
`Inc., Los Angeles, Calif., or may be manufactured by any
`other coil braider.
`
`One embodiment of the present invention, as illustrated in
`FIG. 3, comprises a crimping means consisting of a die 36
`having a first end 40, a second end 44 and a bore 48 within.
`The longitudinal axis of the bore is coincident with the
`longitudinal axis of the cathater 22. The bore is sized to
`crimp a stent carried on catheter 22 within tube 10 to its
`mounted diameter which is smaller than the initial diameter
`
`of the stent. Tube 10 as shown partially rests within bore 48
`of die 36. The stent, located underneath tube 10 and not
`depicted in the FIG. 3,
`is crimped to the catheter by
`
`6
`providing tension to tube 10 thereby reducing its diameter
`and causing it to grip the stent and by sliding die 36 along
`tube 10 and catheter 22, over the stent and tube. As depicted
`in FIG. 3, the bore may optionally be tapered at the second
`end 44, the diameter of the bore at the second end of the die
`44 having a diameter smaller than the initial diameter of the
`stent i.e. the desired crimped diameter. Alternatively,
`the
`bore may be tapered inward from both ends. Thus,
`the
`diameter of the bore at the first end of the tube and at the
`second end of the tube will be greater than the diameter of
`the bore in the middle of the tube. Die 36 may be made of
`any material that is harder or less deformable than the stent
`to be crimped including metals such as stainless steel and
`polymers such as polycarbonate, acrylonitrile-butadiene-
`styrene copolymer, Nylon, acetal, and PEEK
`(polyetheretherketone).
`Tube 10 may further comprise a lubricious coating on the
`exterior surface to facilitate the sliding movement of die 36
`over tube 10 or on the interior surface to facilitate insertion
`of catheter 22 and stent 26 therein. Suitable lubricious
`coatings include, but are not limited to, silicone and hydro-
`phillic coatings involving hydrogel polymers or the like,
`such as polymer networks of a vinyl polymer and an
`uncrosslinked hydrogel, for example. Polyethylene oxide
`(PEO) is a preferred hydrogel. A preferred vinyl polymer is
`neopentyl glycol diacrylate (NPG). Other compositions
`include copolymers of poly(ethylene-maleic anhydride).
`Such compositions are more fully disclosed in copending
`US. patent application “Lubricity Gradient for Medical
`Devices”, Ser. No. 08/868301, filed Jun. 3, 1997, and in
`copending US. patent application Ser. No. 08/409797 filed
`Mar. 24, 1995, both of which are assigned to the same
`assignee as is the present invention and which are incorpo-
`rated herein by reference as well.
`The apparatus may further comprise a die sliding device
`to facilitate sliding the die over the stent. The die sliding
`device provides a track along which the die may be slidably
`moved. The die sliding device may be made of metals such
`as stainless steel and polymers such as polycarbonate,
`acrylonitrile-butadiene-styrene copolymer and PEEK
`(polyether ether ketone).
`In one embodiment, illustrated in FIG. 4, a die sliding
`device generally designated at 100 consists of a base 104
`with two vertical oriented end members 108 and 112 ema-
`
`nating therefrom. Vertical end 108 has aperture 114 formed
`therein, while vertical end 112 has a male conical protrusion
`115 therefrom with an aperture 116 formed therein. The
`diameter of aperture 116 is large enough to accommodate the
`largest diameter catheter 120 desired to be used with the
`present invention. A die 122 has an elongated groove 124
`formed on its bottom and is slidably mounted by means of
`groove 124 on a track 128. An inner tube 138 is attached
`either adhesively or by pressing to male protrusion 115 at
`end member 112 and extends through aperture 114 at the
`other end member 108. In use, catheter 120 is inserted
`through aperture 116 into inner tube 138. Stent 140 is placed
`over the expandable stent bearing portion of the catheter
`142. Inner tube 138 is placed under tension by pulling on end
`138a causing the inner tube to grip stent 140 and hold it in
`place over the expandable stent bearing region of catheter
`142. Die 122 is then slidably moved along the track 128 and
`over expandable stent bearing region of the catheter 142 as
`indicated by the arrow until stent 140 is crimped. Catheter
`120 may then be removed after slidably moving die 122
`back over the stent to its initial position as shown in the
`Figure. Of course stent 140 and expandable stent bearing
`region of catheter 142 must be inserted far enough into inner
`tube 138 to allow the die to pass over them.
`
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`5,992,000
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`7
`illustrated in FIG. 5, a Y or
`In another embodiment,
`similar shaped frame generally indicated at 150 having a
`handle 152 and uprights 154 and 158, has two rods 162 and
`166 mounted between uprights 154 and 158. A tubular or
`conical protrusion 175 with an aperture 174 therethrough
`extends out from upright 154. Aperture 174 extends through
`upright 154. A second aperture 176 extends through upright
`158. A die 178, having three bores 182, 186 and 190 is
`slidably mounted on the rods 162 and 166 by means of bored
`182 and 186, respectively. Rod 162 traverses bore 182 while
`rod 166 traverses bore 186. An inner tube 192 die extending
`outwardly through aperture 174 folded back over and fas-
`tened to protrusion 175 at one end, extends through die 178
`and bore 190 therein and out through aperture 176 in upright
`158.
`Inner tube 192 may be adhesively bonded to the
`protrusion or pressed on. Alternatively, protrusion 175 may
`be threaded (not shown) and a threaded collar (not shown)
`screwed on, with the folded back portion of inner tube 192
`wedged between the collar and protrusion 175.
`In use,
`catheter 194 is inserted in inner tube 192 through aperture
`174 in upright 154, and at least partially into bore 190 in die
`178. Stent 193 is carried on the catheter over the stent
`
`bearing region of the catheter indicated generally at 198.
`Tension is applied to inner tube 192 by pulling on the end
`192a emanating from aperture 176 thereby gripping stent
`193 and holding it in place over the stent bearing region of
`the catheter at 198. Die 178 is slidably moved along rods 182
`and 186 as indicated by the arrow such that stent bearing
`region 198 of catheter 194 passes through bore 190 thereby
`crimping the stent.
`FIG. 6 is a side view of a die 200, similar to those depicted
`in FIGS. 3—5, showing stent bearing region generally indi-
`cated at 204 of a catheter 208 as it traverses a bore 212. Stent
`
`216 is compressed and crimped as it traverses bore 212 by
`movement of die 200 is indicated by the arrow. Extending
`through bore 212 is inner tubing 217.
`In another embodiment, illustrated in FIG. 7, a catheter
`350 having a stent bearing region generally indicated at 354,
`with a balloon 358 mounted thereon, and a stent 362, the
`stent having a first end 363 and a second end 364,
`is
`provided with a first peel away tube 366. First peel away
`tube 366, characterized by a predetermined inner diameter,
`366a, is located adjacent to the second end 364 of stent 362
`and serves as a stent retention means to prevent stent 362
`from sliding along catheter 350 during crimping. A tapered
`peel away tube 370 having a first end 374 with a first
`diameter and a second end 378 with a second diameter, the
`second diameter being larger than the first diameter, sur-
`rounds a portion of catheter 350 at the first end 363 of the
`stent 362 when moved as indicated by the arrow. Tapered
`peel away tube 370 serves as a crimping means. The second
`diameter of tapered peel away tube 370 is larger than the
`diameter of uncrimped stent 362 while the first diameter of
`tapered peel away tube 370 is smaller than the diameter of
`the uncrimped stent. Optionally,
`the stent may rest in a
`sleeve (not shown) to prevent nicking or other damage to the
`stent. In use, tapered peel away tube 370 is slidably passed
`over stent 362 when moved as indicated by the arrow. As the
`tapered end of tapered peel away tube 370 passes over stent
`362, the stent is crimped. Following crimping first peel away
`tube 366 and tapered peel away tube 370 may then be peeled
`away from catheter 350. Optionally, a two part sleeve which
`can be broken off may be used to crimp the stent in place of
`the tapered peel away tube.
`Suitable materials for the first peel away tube and the
`tapered peel away tube include scored polyethylene,
`polypropylene and tefion. Preferably tapered peel away tube
`
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`8
`will 370 be made of a clear or translucent material. Tapered
`peel away tube 370 must be made of a material
`less
`deformable than the stent so that as it passes over the stent,
`the stent will be crimped rather than the tube being
`deformed. The first peel away tube 366 may be formed of
`any material rigid enough to prevent the stent from sliding.
`In another embodiment, the present invention discloses a
`stent-crimping apparatus comprising a deformable tube and
`a tension applying means for applying tension to the deform-
`able tube and a method of crimping a stent using the same.
`The stent bearing region of a catheter, along with a stent, is
`inserted into the deformable tube. As the tension applying
`means stretches the deformable tube, the diameter of the
`tube decreases, thereby crimping the stent onto the catheter.
`As depicted in FIG. 8, a catheter 420 bearing a balloon
`422 is inserted in a deformable tube 424. Stent 426 is
`
`separately inserted into deformable tube 424 so that it rests
`over at least a portion of balloon 422. Deformable tube 424
`has grips 430 at each end. While grips 430 may be an
`integral part of deformable tube 424,
`they may also be
`adhesively or pressure bonded to deformable tube 424.
`Deformable tube 424 will preferable be formed of a braid,
`the characteristics of which have been discussed herein
`
`above. Grips 430 may be made of any material which
`facilitates holding onto the device., including plastics and
`metals. In operation, a stent 426 is aligned over balloon 422
`and tension applied to both grips 430 so as to stretch
`deformable tube 424. As deformable tube 424 stretches, its
`diameter decreases,
`thereby applying an inward force to
`stent 426 and crimping it to balloon 422 and catheter 420.
`The apparatus, shown in FIG. 9 illustrates an embodiment
`of the above invention. The apparatus comprises a deform-
`able tube 450 fixed at a first end 454 to a first arm 456, and
`fixed at a second end 458 to a second arm 460. The two arms
`
`are pivotally connected at 464. The first and second arms
`have apertures 468 and 472