Ulllted States Patent [19]
`Morales
`
`[54] STENT CRIMPING TOOL AND METHOD OF
`USE
`
`[75] Inventor: gtelpfhen A. Morales, Mountain View,
`
`a 1 .
`
`[73] Assigneei Advanced CardiOVaSClllaI‘ Systems,
`Inc., Santa Clara, Calif.
`
`[21] Appl. No.: 893,936
`[22] Filed:
`Jul. 15, 1997
`
`6
`Int. Cl. ......................... .. A61M 29/00; A61B 17/00
`[51]
`[52] US. Cl. .................................... .. 606/198; 606/1
`[58] Field Of Search .............................. .. 606/1, 108, 191,
`606/192’ 194’ 195i
`
`[56]
`
`/
`References Cited
`
`’
`
`’
`
`’
`
`US, PATENT DOCUMENTS
`
`4,907,336
`5,132,066
`5,133,732
`5,183,085
`5,546,646
`
`3/1990 Gianturco .
`7/1992 Charlesworth et a1. .
`7/1992 Wiktor.
`2/1993 Timmermans .
`8/1996 Williams et a1. .
`
`US005810873A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,810,873
`Sep. 22, 1998
`
`5,626,604
`5,630,830
`5,672,169
`
`5/1997 Cottone, Jr. ........................... .. 606/198
`5/1997 Verbeek.
`9/1997 Verbeek .................................... .. 623/1
`OTHER PUBLICATIONS
`
`The eXTraordinary Stent, C.R. Bard Brochure (Undated).
`Application for Us. Letters Patent No. 08/837,771 ?led
`Apr. 22, 1997.
`Application for Us. Letters Patent No. 08/795,335 ?led
`Feb. 4, 1997.
`Primary Examiner—William LeWis
`Attorney, Agent, or Firm—FulWider Patton Lee & Utecht,
`LLP
`
`ABSTRACT
`[57]
`Adevice for enabling crimping of an intravascular stent onto
`a balloon catheter assembly. The stent crimping device
`includes a pair of elements, adapted to be held in the hands
`of the user, Which enable one element, in Which a stent and
`balloon catheter assembly are positioned to slidably move
`relative to the other element, and to move through a tapered
`opening to crimp the stent onto the balloon catheter assem
`bly.
`
`20 Claims, 2 Drawing Sheets
`
`70
`
`Page 1 of 7
`
`Edwards Lifesciences v. Boston Scientific
`U.S. Patent No. 6,915,560
`IPR2017-00072 EX. 2006
`
`

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`U.S. Patent
`U.S. Patent
`
`Sep. 22, 1998
`Sep. 22, 1998
`
`Sheet 1 of2
`Sheet 1 0f2
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`5,810,873
`5,810,873
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`.OIOIOXOKI
`Z7//////75‘
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`FIG. 2
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`"’
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`P76‘.
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`3%
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`Page 2 of 7
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`Page 2 of 7
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`U.S. Patent
`
`Sep. 22, 1998
`22222222298
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`Sheet 2 of2
`
`5,810,873
`5,810,873
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`Page 3 of 7
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`

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`5,810,873
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`1
`STENT CRIMPING TOOL AND METHOD OF
`USE
`
`BACKGROUND OF THE INVENTION
`
`2
`catheter When the catheter is advanced in the patient’s
`vasculature. In the past this crimping Was often done by
`hand, Which does not provide optimum results due to the
`uneven force being applied, resulting in non-uniform
`crimps. In addition, it was difficult to judge When a uniform
`and reliable crimp had been applied. Though some tools,
`similar to ordinary pliers, have been used to apply the stent,
`these tools have not been entirely adequate in achieving a
`uniform crimp. Moreover, an unevenly crimped stent may
`result in an unevenly expanded stent in the vessel or artery,
`Which is undesirable.
`The present invention solves the problems associated With
`the prior art devices and provides a crimping tool that tightly
`and uniformly crimps the stent on the balloon portion of the
`catheter.
`
`SUMMARY OF THE INVENTION
`
`The invention is directed to a stent crimping device Which
`enables crimping of a stent onto a catheter balloon portion,
`to better secure the stent onto the catheter for delivery of the
`stent through the patient’s vasculature.
`In an exemplary embodiment of the present invention, the
`stent crimping device includes a pair of elements adapted to
`be held in the hands of the user, to enable the user to move
`one element relative to the other, and to slide the stent and
`balloon catheter assembly, connected to one element,
`through a restricted opening in the other element, through
`Which the stent and balloon catheter assembly are slidably
`movable. The restricted opening applies compressive force
`on the stent and balloon catheter assembly, to crimp the stent
`onto the balloon catheter assembly.
`The device enables the stent to be tightly and uniformly
`crimped onto the distal end of a balloon catheter, reducing
`the risk that the stent may slide off the catheter balloon
`portion.
`These and other advantages of the invention Will become
`more apparent from the folloWing detailed description
`thereof When taken in conjunction With the accompanying
`draWings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a partial sectional elevational vieW of an
`exemplary embodiment of the present invention, prior to
`slidably moving the stent and catheter balloon assembly
`through a restricted opening in an element.
`FIG. 2 is a vieW similar to FIG. 1 after the stent and
`catheter balloon portion have slidably moved through the
`restricted opening such that the stent is crimped onto the
`catheter balloon portion.
`FIG. 3 is a side partial fragmentary elevational vieW of the
`element from Which strands and the balloon catheter extend.
`FIG. 4 is an end elevational vieW of the element shoWn in
`FIG. 3, taken along line 4—4 of FIG. 3.
`FIG. 5 is a side elevational sectional vieW of the element
`through Which the stent and catheter balloon portion are
`slidably movable.
`FIG. 6 is an end elevational vieW of the element shoWn in
`FIG. 5, taken along line 6—6 of FIG. 5.
`
`1. Field of the Invention
`The invention relates to a stent crimping device of the
`type that Will enable the user to crimp a stent onto the distal
`end of a balloon catheter assembly, for example, of the kind
`used in a typical percutaneous transluminal coronary angio
`plasty (PTCA) or percutaneous transluminal angioplasty
`(PTA) procedure.
`2. Description of the Related Art
`In a typical PTCA procedure, for compressing lesion
`plaque against the artery Wall to dilate the artery lumen, a
`guiding catheter is percutaneously introduced into the car
`diovascular system of a patient through the brachial or
`femoral arteries and advanced through the vasculature until
`the distal end is in the ostium of the aorta. A guideWire and
`a dilatation catheter having a balloon on the distal end are
`introduced through the guiding catheter With the guideWire
`sliding Within the dilatation catheter. The guideWire is ?rst
`advanced out of the guiding catheter into the patient’s
`coronary vasculature, and the dilatation catheter is advanced
`over the previously advanced guideWire until the dilatation
`balloon is properly positioned across the lesion. Once in
`position across the lesion, the balloon is in?ated to a
`predetermined siZe With radiopaque liquid at relatively high
`pressures to radially compress the atherosclerotic plaque of
`the lesion against the inside of the artery Wall and thereby
`dilate the lumen of the artery. The balloon is then de?ated to
`a small pro?le, so that the dilatation catheter can be With
`draWn from the patient’s vasculature and blood ?oW
`resumed through the dilated artery. While this procedure is
`typical, it is not the only method used in angioplasty.
`In angioplasty procedures of the kind referenced above,
`restenosis of the artery may develop over several months,
`Which may require another angioplasty procedure, a surgical
`bypass operation, or some method of repairing or strength
`ening the area. To reduce the chance of the development of
`restenosis and strengthen the area, an intravascular prosthe
`sis is implanted for maintaining vascular patency, typically
`called a stent. A stent is a device used to hold tissue in place
`in a vessel or to provide a support for a vessel to hold it open
`so that blood ?oWs freely. Avariety of devices are knoWn in
`the art for use as stents, including balloon expandable
`tubular members, in a variety of patterns, that are able to be
`crimped onto a balloon catheter, and expanded after being
`positioned intraluminally on the balloon catheter, and that
`retain their expanded form. Typically, the stent is loaded and
`crimped onto the balloon portion of the catheter, and
`advanced to a location inside the artery after a PTCA or PTA
`procedure. The stent is then expanded to a larger diameter,
`by the balloon portion of the catheter, to implant the stent in
`the artery. Typical stents and delivery catheters are disclosed
`in US. Pat. Nos. 5,514,154 (Lau et al.), 5,569,295 (Lam)
`and 5,507,768 (Lau et al.), Which are incorporated herein by
`reference.
`HoWever, if the stent is not tightly crimped onto the
`catheter balloon portion, When the catheter is advanced in
`the patient’s vasculature the stent may move or even slide off
`the catheter balloon portion in the coronary artery prior to
`expansion, and may block the How of blood, requiring
`procedures to remove the stent.
`In procedures Where the stent is placed over the balloon
`portion of the catheter, the stent must be crimped onto the
`balloon portion to prevent the stent from sliding off the
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`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
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`65
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`The stent crimping device of the present invention is
`designed to alloW a catheter lab (cath lab) physician or
`personnel to crimp a stent onto the balloon portion of a
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`Page 4 of 7
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`5,810,873
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`catheter. The stent crimping device Will allow cath lab
`personnel to crimp essentially any type of balloon
`expandable stent onto any type of balloon catheter, such as
`a typical balloon dilatation catheter used in a PTCA or PTA
`procedure.
`The stent crimping device is formed generally of tWo
`parts including a handle portion and a cylinder portion
`Which are designed to be held in the user’s hands for
`draWing the stent and balloon through the tapered cylinder
`portion to crimp the stent onto the balloon. The handle and
`cylindrical portion are depicted as having preferred shapes,
`hoWever, as Will be appreciated these shapes can be modi?ed
`to suit speci?c cath lab requirements or to accommodate
`stent and balloon catheter assemblies having various dimen
`sions.
`As can be seen in FIGS. 1 and 2, stent crimping tool 10
`comprises handle element 20 and cylindrical element 22 for
`crimping an intravascular stent 11 onto the collapsed balloon
`portion 12 of a balloon catheter assembly 13. In the exem
`plary embodiment of tool 10, as shoWn in FIGS. 1—6, handle
`element 20 and cylindrical element 22 are adapted to be held
`in the hands of the user, so as to enable the user to slide stent
`11 and balloon catheter portion 12 through the cylindrical
`element, to apply compressive force thereto to crimp the
`stent onto balloon portion of the catheter.
`As shoWn in FIGS. 3 and 4, handle element 20 includes
`an opening 24 therein, in Which ?rst end 14 of catheter 15
`is insertable so as to be releasably retained therein. First ends
`26 of a plurality of thin elongated strands 28, comprised of
`?exible material, are secured in opening 24, and strands 28
`extend therefrom so as to be extendable along and about
`catheter 15 and stent-loaded balloon catheter portion 12
`thereof.
`Opening 24 may have a diameter, for example, ranging
`from about 0.0500 to 0.2000 inch, With six sections 30
`formed therein extending arcuately at 60° angles, for secur
`ing ?rst ends 26 of elongated strands 28 therein. The
`elongate strands 28, having six sections 30, essentially form
`a cylindrical tube for receiving the stent and balloon prior to
`and during the crimping procedure. Depending upon the
`diameter of opening 24, it may be necessary to increase or
`decrease the number of sections 30, Which may range from
`a single annular section up to perhaps tWelve sections.
`Sections 30 are preferably arcuate-shaped, but can be ?at or
`rectangular.
`Handle element 20 further includes a reduced diameter
`gripping portion 34 for enabling the user to grip and pull
`elongate strands 28 through the cylindrical element.
`Cylindrical element 22, as depicted in FIGS. 5 and 6,
`includes channel 36 extending therethrough. Catheter 15,
`stent-loaded balloon catheter portion 12 thereof, and strands
`28 all are slidably-movable through channel 36. Channel 36
`includes channel ?rst portion 38 having a diameter greater
`than the diameter of stent-loaded balloon catheter portion 12
`and strands 28, tapering to a reduced diameter substantially
`the same as the diameter of stent-loaded balloon catheter
`portion and strands 28. The diameter of channel ?rst portion
`38 may, for example, taper from a diameter of 0.250 inch to
`a diameter of 0.034 inch. Channel 36 includes channel
`second portion 40 having a diameter substantially the same
`as the diameter of stent-loaded balloon catheter portion and
`strands 28 after crimping stent 11 onto balloon catheter
`portion 12. For example, the diameter of channel second
`portion 40 may be a constant 0.034 inch. Since the diameter
`of channel second portion 40 de?nes the stent crimped
`diameter, the diameter can vary depending upon the appli
`cation.
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`4
`In the preferred method of crimping, the stent is loaded
`onto the de?ated balloon portion of the catheter assembly.
`The elongate strands 28 are already positioned and extend
`ing through the cylindrical element and ?ared outWardly to
`receive balloon portion 12 and stent 11 of catheter assembly
`13. The user then grips handle element 20 in one hand and
`cylindrical element 22 in the other hand and pulls the tWo
`assemblies in opposite directions so that the elongate strands
`28 collapse onto the stent and balloon portion of the catheter
`assembly. Continued pulling of the assemblies in opposite
`directions results in the stent and balloon portion of the
`catheter assembly to be draWn through the continually
`narroWing taper formed in the second cylindrical element.
`The stent is gradually crimped onto the balloon portion of
`the catheter assembly as it is pulled through the taper and
`into and through channel second portion 40, the diameter of
`Which substantially de?nes the crimped diameter of the stent
`With the thickness of the elongate strands around the stent.
`Continued pulling of the handle element in the opposite
`direction of the cylindrical element permits elongate strands
`28 to be pulled clear of the second cylindrical element along
`With the noW crimped stent. Thereafter, the stent and balloon
`portion of the catheter assembly can be carefully pulled back
`through the cylindrical element Without the elongate strands,
`resulting in the stent being tightly crimped onto the balloon
`portion of the catheter.
`The stent crimping tool 10 is designed to come either
`assembled or unassembled so that the cath lab personnel can
`choose the appropriate diameter of the channel second
`portion 40. The inner diameter of the channel second
`portion, in one preferred embodiment, may be about 0.034
`inch. It Will be appreciated, hoWever, that this diameter can
`vary substantially depending upon the diameter of a de?ated
`balloon, including the diameter or thickness of the stent
`When crimped onto the balloon, taken in conjunction With
`the diameter of the vessel Which receives the implanted
`stent. Thus, for example, for a saphenous vein graft (SVG),
`the inner diameter of cylindrical element 22 may be much
`larger than 0.034 inch. As is clear, the resulting diameter of
`the stent as crimped onto the balloon is a matter of choice of
`the cath lab personnel to ?t the particular application.
`As can be appreciated, stent crimping tool 10 is designed
`for crimping stents having various diameters onto the bal
`loon portion of a catheter. In order to more easily accom
`modate varying diameters of stents and to insure that the
`crimping process is smooth and results in a non-locking
`taper, the taper created by channel ?rst portion 38 as it
`reduces in diameter to channel second portion 40, preferably
`angles in range of about 100 to 200 from the longitudinal
`axis of channel 36.
`The stent crimping tool is designed for one-time use in a
`cath lab and it is intended to be destroyed after each use so
`that steriliZation after use does not become a factor. The stent
`crimping device also can be used by stent and catheter
`manufacturers to crimp their stents onto catheters and pack
`age the assembly for sale to cath labs.
`In one preferred embodiment, the handle element and the
`cylindrical element are formed from a rigid plastic Which is
`capable of being machined into the speci?c dimensions for
`optimal performance. The inner diameter of cylindrical
`element 22 typically Will be bored so that precise diameters
`can be achieved, since it Will de?ne the ?nal crimped
`diameter of the stent. Moreover, it is important to provide a
`channel that is uniform and free of machining irregularities
`such as nicks or ridges. Thus, channel 40 preferably is bored
`or machined to provide precise diameters.
`In order to facilitate draWing the elongate strands through
`the tapered bore or channel of the cylindrical element, a
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`Page 5 of 7
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`5,810,873
`
`5
`lubricous coating can be added to either elongate strands 28
`channel 36 or both. The channel, Which is a tapered bore, can
`have a lubricous coating Which allows the ?exible strands to
`more easily be pulled therethrough. Further, the elongate
`strands also can have a lubricous coating to ensure that they
`are easily pulled through the channel While crimping the
`stent onto the balloon portion of the catheter. Importantly,
`the elongate strands should be thin, ?exible and compliant
`members, and be made from elastomeric materials, mylar, or
`the like.
`While in the preferred embodiment the stent described is
`intended to be an intraluminal vascular prosthesis for use
`Within a blood vessel, and the balloon delivery catheter is the
`same as or similar to that used in PTCA or PTA procedures,
`it Will be appreciated by those skilled in the art that modi
`?cations may be made to the present invention to crimp any
`type of stent on any catheter. The present invention is not
`limited to stents that are deployed in a patient’s vasculature,
`but has Wide applications to crimping any type of graft,
`prosthesis, liner or similar structure. Furthermore, the stent
`may be delivered not only into coronary arteries, but into
`any body lumen. Other modi?cations can be made to the
`present invention by those skilled in the art Without depart
`ing from the scope thereof.
`What is claimed is:
`1. A crimping tool assembly for crimping a stent onto a
`balloon catheter assembly, the crimping tool assembly com
`prising:
`a handle having a plurality of elongate strands attached
`thereto, the elongate strands being formed of a ?exible
`material;
`a cylindrical element having a tapered bore extending at
`least partially therethrough, the tapered bore further
`having an inner diameter substantially de?ning the
`diameter of the stent When crimped onto the balloon
`catheter;
`Whereby the elongate strands extend through the tapered
`bore and inner diameter and the stent is positioned over
`the balloon portion of the balloon catheter With the
`elongate strands positioned around the stent and
`balloon, the stent is crimped onto the balloon as the
`handle is used to pull the elongate strands through the
`tapered bore, Which in turn crimps the stent around the
`balloon portion of the catheter.
`2. The assembly of claim 1, Wherein the elongate strands
`are attached to a plurality of sections forming a substantially
`cylindrical tube in Which the stent and balloon portion of the
`catheter are partly inserted prior to the crimping operation.
`3. The assembly of claim 2, Wherein the plurality of
`sections each form an arcuate section of approximately 60
`degrees, thereby forming the substantially cylindrical tube.
`4. The assembly of claim 1, Wherein the handle and
`cylindrical element are formed from a rigid plastic material.
`5. The assembly of claim 1, Wherein the elongate strands
`are formed from a ?exible elastomeric material.
`6. The assembly of claim 1, Wherein the cylindrical
`element includes a ?rst diameter de?ning channel ?rst
`portion and gradually tapering to a second diameter de?ning
`channel second portion, the second diameter being smaller
`than the ?rst diameter and substantially corresponding to the
`crimped diameter of the stent With the strands around the
`stent.
`7. The assembly of claim 6, Wherein the ?rst diameter is
`in the range of 0.250 to 0.500 inch and tapering to the second
`diameter in the range of 0.034 to 0.250 inch.
`8. The assembly of claim 1, Wherein the tapered bore
`includes a lubricous coating to facilitate draWing the elon
`
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`gate strands therethrough When crimping the stent onto the
`balloon portion of the catheter.
`9. The assembly of claim 1, Wherein the tapered bore is
`formed from a lubricous material to facilitate draWing the
`elongate strands therethrough When crimping the stent onto
`the balloon portion of the catheter.
`10. The assembly of claim 1, Wherein the cylindrical
`element and the elongate strands include a lubricous coating
`to facilitate draWing the strands through the tapered bore
`When crimping the stent onto the balloon portion of the
`catheter.
`11. A crimping tool assembly for crimping a stent onto a
`balloon catheter assembly, the crimping tool assembly com
`prising:
`means for releasably retaining a ?rst end of a catheter
`therein, Which catheter includes a balloon portion on
`Which a stent may be loaded, including means mounted
`in the retaining means and adapted to be extendable
`therefrom so as to be extendable along and about the
`catheter and the stent-loaded balloon catheter portion;
`and
`means having a tapered bore for enabling the catheter, the
`stent-loaded balloon catheter portion, and the extend
`able means to extend and be slidably movable
`therethrough, so as to apply compressive force via the
`tapered bore to the stent-loaded balloon catheter
`portion, for crimping the stent onto the balloon catheter
`portion.
`12. The assembly of claim 11, Wherein the extendable
`means comprise a plurality of strands.
`13. The assembly of claim 11, Wherein the slidable
`movement enabling means include a channel extending
`therethrough.
`14. The assembly of claim 12, Wherein the plurality of
`strands are comprised of ?exible material.
`15. The assembly of claim 14, Wherein the channel further
`includes a portion having a diameter greater than the diam
`eter of the stent-loaded balloon catheter portion and the
`extendable means after crimping of the stent onto the
`balloon catheter portion.
`16. A crimping tool assembly for crimping an intravas
`cular stent onto a balloon catheter assembly, the crimping
`tool assembly comprising:
`a device adapted to enable slidable movement of the
`stent-loaded balloon catheter portion through a channel
`having a diameter Which decreases to the crimped
`diameter of the stent-loaded balloon catheter; and
`thin strands extending through the channel terminated by
`a handle at an end and arrayed open at an opposite end
`Wherein the strands at least partially envelope the stent
`positioned on the balloon catheter assembly.
`17. A method of crimping an intravascular stent onto a
`balloon catheter assembly, comprising:
`inserting a balloon portion of a catheter, on Which a stent
`may be loaded, into a channel, the diameter of Which
`decreases from substantially greater than the diameter
`of the stent-loaded balloon catheter portion and an
`extendable means extending therealong and thereabout
`to a reduced diameter substantially the same as the
`diameter of the stent-loaded balloon catheter portion
`and the extendable means after crimping of the stent
`onto the balloon catheter portion; and
`sliding the stent-loaded balloon catheter portion through
`the channel from the diameter substantially greater than
`the diameter of the stent-loaded balloon catheter por
`tion and the extendable means through the reduced
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`5,810,873
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`7
`diameter substantially the same as the diameter of the
`stent-loaded balloon catheter portion and extendable
`means after crimping of the stent onto the balloon
`catheter portion, to crimp the stent onto the catheter
`portion.
`18. The method of claim 17, Wherein the step of inserting
`the stent-loaded balloon catheter portion into the channel
`comprises inserting the balloon catheter portion into the
`diameter of the channel substantially greater than the diam
`eter of the stent-loaded balloon catheter portion and a
`plurality of ?exible strands extending therealong and there
`about.
`19. A method of crimping a stent onto the balloon portion
`of a catheter assembly comprising:
`providing a stent crimping device including the handle
`portion having a plurality of elongate strands attached
`thereto, a cylindrical element having a tapered bore
`extending therethrough, at least a portion of the tapered
`bore having an inner diameter substantially de?ning the
`diameter of the stent When crimped onto the balloon
`portion of the catheter;
`positioning the elongate strands through the tapered bore
`in the cylindrical element;
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`positioning the stent over the balloon portion of the
`catheter, and positioning the stent and balloon portion
`of the catheter Within the elongate strands;
`pulling the handle With one hand in one direction and the
`cylindrical in the other hand in the opposite direction
`thereby pulling the elongate strands and the stent and
`balloon portion of the catheter through the tapered
`bore;
`crimping the stent onto the balloon portion of the catheter
`as the elongate strands and the stent and balloon portion
`of the catheter pass through the inner diameter of the
`tapered bore; and
`WithdraWing the crimped stent and balloon portion of the
`catheter through the tapered bore.
`20. The method of claim 19, further comprising applying
`a biocompatible lubricous coating to the tapered bore and
`the elongate strands prior to the step of positioning the stent
`and balloon portion of the catheter With in the elongate
`strands.
`
`Page 7 of 7
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