United States Patent
`
`[191
`
`[11] Patent Number:
`
`5,672,169
`
`Verbeek
`[45] Date of Patent:
`Sep. 30, 1997
`
`
`USOOS672 169A
`
`[54] STENT MOUNTING DEVICE
`
`[75]
`
`Invcntor: Marcel A. E. Verbeek. Gales“,
`Netherlands
`
`5,368,566 11/1994 Cracker ................................... 604/101
`
`5,387,235
`2/1995 Clutter ..............
`623/1
`u. GOG/108
`5,391,172
`2/1995 Williams 6131..."
`
`10/1995 Langton ct al. ............ 600/7
`5,460,592
`
`[’73] Assignee: Medtronic, Inc, Minneapolis. Minn.
`
`[21] Appl. No.: 630,183
`[22] Filed:
`Apr. 10, 1996
`
`OTHER PUBLICATIONS
`Rupp. et al., Patent Application “Stent Mounting and Trans-
`fer Device and Method", filed Dec. 21, 1995. USSN 08/576.
`720'
`
`Int. Cl.6 ..................................................... A613 17/00
`[51]
`
`[52] US. Cl. ............
`. 606/1; 606/192; 623/1
`[58] Field of Search ..................................... 606/108, 194.
`606/195. 193. 1. 151; 623/1, 12
`
`Primary Examiner—Robert A. Hafer
`ASSiStaflt Exammer—JUSfinc R. Yu
`Attorney, Agent, or Firm—John R- Duncan: Dianne M- F-
`Plunkett: Harold Ru Patton
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,726,369
`4,800,882
`5,026,377
`5,108,416
`5,147,302
`5,158,548
`5,190,058
`5,192,297
`5,201,757
`5,226,889
`5,242,399
`5,266,073
`5,304,340
`5,306,294
`5,328,469
`5,338,296
`5,344,426
`5,360,401
`
`2/1988 Mar ............................................. 606/1
`1/1989 Gianturco
`. 606/194
`
`6/1991 Burton et al.
`606/108
`
`.........
`4/1992 Ryan etal.
`6061194
`9/1992 Euteneuer et a1.
`..
`606/194
`
`10/1992 Lan et a1.
`...... 604/96
`
`.
`3/1993 Jones et al.
`128/898
`
`3/1993 Hull
`............
`6061195
`
`4/1993 Heyn et a1.
`.
`606/198
`
`7/1993 Sheiban .......
`.. 604/101
`
`9/1993 Lau et a].
`.
`604/104
`
`623/1
`11/1993 Wall
`.
`606/194
`4/1994 Downey
`
`4/1994 Mnston et a1.
`.
`........ 623/1
`
`7/1994 Coletti .................
`606/194
`8/1994 Dalessandro et al.
`...... 604/96
`9/1994 Lau et a1.
`.............
`606/198
`11/1994 Turnland ................................... 604/96
`
`
`
`ABSTRACT
`[57]
`A stent mounting device and method of using the device
`comprising a disposable device for holding a stent. into
`which a delivery system such as a balloon catheter can be
`inserted, and the stent crimped onto the delivery system,
`after which the delivery system and mounted stent are
`removed from the device. A stent is carried in a channel
`
`formed by four corner segments of four co—axfllay arranged
`spaced blocks. 'IWo adjacent blocks are elastically mounted
`in each of two parallel. opposed. cooperating actuators. The
`corner segments form an elongated channel sized to retain a
`conventional stent. Two elastic rods are placed between
`opposite blocks in opposite actuators. When the actuators
`are pressed together the rods are deformed to provide
`pressure transverse to the line of pressure, so that the cross
`sectional area of the channel is decreased in both directions,
`crimping the stent uniformly onto a delivery system.
`
`12 Claims, 2 Drawing Sheets
`
`
`
`Edwards Lifesciences v.
`
`Boston Scientific
`
`US. Patent No.
`
`6,915,560
`IPR2017-00444
`
`EX. 2037
`
`Page 1 of 7
`
`Page 1 of 7
`
`

`

`US. Patent
`
`5,672,169
`
` FIGURE 2
`
`Page 2 of 7
`
`Page 2 of 7
`
`

`

`US. Patent
`
`Sep. 30, 1997
`
`Sheet 2 of 2
`
`5,672,169
`
`
`
`FIGURE 3
`
`FIGURE 4
`
`FIGURE 5
`
`Page 3 of 7
`
`Page 3 of 7
`
`

`

`1
`STENT MOUNTING DEVICE
`
`FIELD OF THE INVENTION
`
`This invention relates in general to intervascular stent
`implants for maintaining vascular patency in humans and
`animals and more particularly to a method and apparatus for
`supporting a stent and for transferring the stent to a delivery
`system such as a balloon catheter.
`
`BACKGROUND OF THE INVENTION
`
`Percutaneous translurninal coronary angioplasty (PTCA)
`is used to reduce arterial build-up of cholesterol fats or
`atherosclerotic plaque. Typically a guidewire is steered
`through the vascular system to the site of therapy. A guiding
`catheter. for example, can then be advanced over the
`guidewire and a balloon catheter advanced within the guid-
`ing catheter over the guidewire. The balloon at the distal end
`of the catheter is inflated causing the site of the stenosis to
`widen. The dilatation of the occlusion. however. can form
`flaps. fissures and dissections which threaten re-closure of
`the dilated vessel or even perforations in the vessel wall.
`Implantation of a metal stent can provide support for such
`flaps and dissections and thereby prevent reclosure of the
`vessel or provide a patch repair for a perforated vessel wall
`until corrective surgery can be performed. Reducing the
`possibility of restenosis after angioplasty reduces the like-
`lihood that a secondary angioplasty procedure or a surgical
`bypass operation will be necessary.
`An implanted prosthesis such as a stent can preclude
`additional procedures and maintain vascular patency by
`mechanically supporting dilated vessels to prevent vessel
`collapse. Stents can also be used to repair aneurysms, to
`support artificial vessels as liners of vessels or to repair
`dissections. Stents are suited to the treatment of any body
`lumen. including the vas deferens, ducts of the gallbladder,
`prostate gland. trachea. bronchus and liver. The body lumens
`range in size from the small coronary vessels to the 30 mm
`aortic vessel. The invention applies to acute and chronic
`closure or reclosure of body lumens.
`A stent typically is a cylindrically shaped device formed
`from wires or a slotted tube and intended to act as a
`permanent prosthesis. A stent is deployed in a body lumen
`from a radially compressed configuration into a radially
`expanded configuration which allows it
`to contact and
`support a body lumen. The stent can be made to be radially
`self—expanding or expandable by the use of an expansion
`device. The self expanding stent is made from a resilient
`springy material while the device expandable stent is made
`from a material which is plastically deformable. A plasti-
`cally deformable stent can be implanted during a single
`angioplasty procedure by using a balloon catheter bearing a
`stent which has been crimped onto the balloon. Stents
`radially expand as the balloon is inflated, forcing the stent
`into contact with the body lumen thereby forming a sup-
`porting relationship with the vessel walls. Deployment is
`effected after the stent has been introduced percutaneously,
`transported transluminally and positioned at a desired loca-
`tion by means of the balloon catheter.
`The metal stent that props open blocked coronary arteries.
`keeps them from reclosing after balloon angioplasty. A
`balloon of appropriate size and pressure is first used to open
`the lesion. The process is repeated with a stent crimped on
`a balloon. The stent is deployed when the balloon is inflated.
`The stent remains as a permanent scafiold after the balloon
`is withdrawn.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`4s
`
`50
`
`55
`
`A number of different stent structures and placement
`instruments have been developed. For example. Wall in US.
`Pat. No. 5.266.073 describes a rolled tubular stent carried at
`the end of a tubular catheter with a second catheter threaded
`
`65
`
`5,672,169
`
`2
`
`therethrough to carry a balloon. The assembly is inserted
`into an artery until the stent is at the proper location. then the
`balloon catheter is positioned within the stent and expanded
`to expand. unroll and lock the stent. This arrangement
`usually requires an undesirably large diameter catheter for
`carrying the stent and includes a complex and possibly
`unreliable locking method for holding the stent
`in the
`expanded position. Also, non-uniform stent expansion may
`occur. since the expanding balloon cannot directly contact
`the portion of the stent that overlaps its carrier catheter.
`Other stent delivery systems have a self-expanding stent
`compressed in a tube, such as that described by Burton et al.
`in U.S. Pat. No. 5.026.377. The tube is inserted until the
`stent is in the desired location and the stent is forced from
`the tube and expands into contact with the vessel wall. A
`balloon catheter may be inserted and expanded to further
`expand the stent. Problems may arise with maintaining the
`partially expanded stent in position and preventing pushing
`the stent out of position during insertion of the balloon
`catheter.
`
`Others have used a rolled tubular stent placed around a
`balloon catheter and covered by a tubular sheath connected
`to a guidewire extending through the catheter. such as is
`described by Lau et al. in US. Pat. No. 5.158.548. The
`assembly is inserted into a desired location in a body lumen.
`the sheath is moved longitudinally by the guidewire away
`from the stent and the balloon is expanded to expand the
`stent. This requires a complex tubular catheter. sheath and
`stent assembly.
`Balloon catheters are available with a stent preloaded
`around the balloon. This requires a second balloon catheter
`to be used to dilate the lesion enough to allow the stent to
`enter. Subsequently. the catheter beating the stent is intro-
`duced and the stent emplaced. This requires the use of two
`expensive catheters to complete placement of the stent and
`two catheterization.
`Loose stents are available which users simply slip over a
`balloon catheter and crimp against the catheter balloon with
`the fingers. While this arrangement is simple and quick. the
`stent may be damaged during storage and handling prior to
`use. while it is being placed over the catheter balloon or
`during the crimping step. Damaged stents cannot be used. If
`damage to the stent is not noticed. the stent may not perform
`as intended in use. Further. depending on the type of
`delivery system, fitting the stent over the delivery end
`without damage is sometimes difficult.
`Excellent methods and apparatus for mounting stents on
`catheter balloons and the like are described by Rupp et al. in
`US. patent application Ser. No. 08/576,720. filed Dec. 21,
`1995 and assigned to the assignee of this application. While
`the methods and apparatus described in that application
`provide excellent results, I have found that in some instances
`a disposable mounting device is preferable.
`Thus, there is a continuing need for improved devices and
`methods for mounting a stent onto a delivery system such as
`a balloon catheter that are simpler. less expensive, more
`convenient, more reliable, avoid damage to the stent and
`include a sterile. disposable, mounting device to avoid
`contact between a sterile stent and catheter and a non-sterile
`surface.
`
`SUMMARY OF THE INVENTION
`
`The above-noted problems, and others, are overcome in
`accordance with this invention by a stent mounting device
`and method of using the device comprising a disposable
`device for holding a stent. into which a delivery system such
`as a balloon catheter can be inserted. then simply squeezing
`the device from opposite sides cfimps the stent onto the
`delivery system. after which the delivery system and
`mounted stent are removed from the device.
`
`Page 4 of 7
`
`Page 4 of 7
`
`

`

`5,672,169
`
`3
`A stent is carried in a channel formed by four corner
`segments of four concentrically spaced blocks. 1W0 adjacent
`blocks are elastically mounted in each of two parallel.
`opposed cooperating actuators. The corner segments form
`an elongated channel sized and shaped to retain a stent of the
`type generally referred to as a Wiktor or Wiktor-I stent or
`other Medtronic Stents. Opposite ends of the two actuators
`are secured to elastic end members which permit the actua.
`tors to be manually moved toward each other. End caps are
`secured over the end members and include guides that guide
`the two actuators toward and away from each other along
`substantially straight lines.
`Holes are provided through the end caps and end mem-
`bers in alignment with the channel so that a catheter or the
`like can be inserted into the channel to align with the stent
`carried by the channel.
`Elastic rods are provided between the actuators along
`lines parallel to the channel. The elastic mounts for the
`blocks are configured so that when a delivery system is
`inside the stent. as the actuators are manually pressed
`together initially the channel is narrowed along the axis of
`applied pressure.
`then the elastic rods press the blocks
`toward the channel transverse to the axis of applied pressure.
`to narrow the channel in that direction. The stent is thus
`uniformly and smoothly pressed against the delivery system
`and crimped thereagainst. When pressure is released on the
`actuators. the channel expands in accordance with the clas-
`ticity of the rods and blocks to essentially the original
`diameter. The delivery system with mounted stent is then
`removed.
`
`The components of this device can be economically
`manufactured by injection molding. or other equivalent
`method. and can be easily bonded together by adhesive,
`ultrasonic. heat or other suitable bonding method. For opti-
`mum assembly. cooperating pins and recesses are provided
`between components to aid in alignment and bonding.
`Preferably. the device is formed from a flexible transparent
`plastic material such as a suitable acrylic resin, allowing
`easy observation of the stent. delivery system and alignment
`before pressing to crimp the stent. Since the manufacturing
`methods and materials are inexpensive, the device can be
`supplied within sterile condition with a stent in place. then
`can be disposed of after a single use.
`In present practice, two “delivery” systems such as bal-
`loon catheters are required for implanting a stent for proce-
`dures such as percutaneous transluminal coronary angio-
`plasty. Typically, a first delivery system, such as a balloon
`catheter is inserted and the balloon expanded to press a
`lesion outwardly and make room for a stent. A balloon
`catheter, preloaded with a stent. is inserted and the stent is
`moved to the desired location and the balloon is expanded to
`expand the stent against the vessel wall. With the device of
`this invention only a single balloon catheter delivery system
`is required. A catheter balloon can be rewrapped after the
`first expansion step. The catheter balloon is then inserted
`into the device and a stent is erimped onto the balloon with
`the device. The stent can be emplaced as before.
`It is, therefore. an object of this invention to provide an
`improved device and method for placing stents onto any of
`a variety of delivery systems. such as wrapped balloon
`catheters. Another object of the invention is to reduce or
`prevent damage to stents dining placement onto delivery
`systems. A further object is to provide a device for mechani-
`cally applying a stent to a delivery system which does not
`require manual finger crimping of the stent. Yet another
`object is to provide an arrangement in which a single balloon
`catheter can be used to dilate a lesion and place a stent at the
`lesion site. Other objects and advantages of the stent instal-
`lation device and method of this invention will become
`apparent upon reading the following description of preferred
`embodiments.
`
`4
`BRIEF DESCRIPTION OF THE DRAWING
`
`Details of the invention. and of preferred embodiments
`thereof, will be further understood upon reference to the
`drawing, wherein:
`FIG. 1 is a perspective view of the stent installation device
`of this invention and a wrapped balloon upon which a stent
`is to be installed;
`FIG. 2 is an exploded view of the stent installation device;
`FIG. 3 is a section View taken on line 3—3 in FIG. 1 prior
`to compressing the device;
`FIG. 4 is a section View taken on line 3—3 in FIG. 1
`subsequent to compressing the device; and
`FIG. 5 is a section view taken on line 5—5 in FIG. 1.
`
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`Referring to FIGS. 1 and 2, there is seen a device 10
`having two generally identical actuator pieces 12.
`two
`elastic guide members 14 and two end caps 16. A stent
`delivery system. such as the balloon catheter 18, with the
`balloon wrapped, as seen in FIG. 1, can be inserted into
`device 10 through hole 20.
`Within each of actuators 12 are formed a pair longitudinal
`blocks 22. as best seen in FIGS. 2—4. Each pair of blocks is
`secured together by a thin web 24 and to the interior of
`actuator 12 by thin webs 26. Actuators 12 are preferably
`formed from a resilient material so that, together with the
`thin webs 24 and 26, the positions of blocks 22 can be
`changed with relatively little force. Each block 22 has a
`corner segment 28 which formes a portion of a central
`channel between the four segments 28.
`Guide members 14 have ends 32 which carry pairs of pegs
`34 which tightly fit in recesses 36 in actuators 12. Pegs 34
`are bonded in recesses 36 in any suitable manner. such as by
`an adhesive. ultrasonic bonding, thermal bonding, etc. N0
`other part of guide members 14 are bonded to actuators 12.
`Each guide member 14 has three outward protuberances,
`two sliding protuberances 38. The inner surface of each end
`cap 16 includes a central recess 42 which fits tightly over
`central protuberance 40 and is bonded thereto by an
`adhesive. etc. Sliding protuberances 38 fit in elongated
`recesses 44 and are slidable therein along a straight line. End
`caps 16 are bonded to guide members 14 only at central
`protuberance 40.
`A pair of elongated elastic rods 46 are positioned in a
`cooperating shallow groove formed at the intersection of
`each opposed surface of actuators 12 and slots 48 between
`the exterior housing of actuators l2 and blocks 22. With
`endcaps 16 and guide members 14 in place on actuators 12.
`rods 46 are held in place with light elastic pressure. Central
`channel 30 is open to the maximum cross sectional area.
`While channel 30 preferably has a general circular cross
`section, other shapes could be used if desired to accommo—
`date other stent cross sections. Channel 30 is open at both
`ends through holes 50 in guide members 14 and end caps 16.
`A stent 52, as seen in FIG. 5, is placed in channel 30
`during assembly of the device and is held in place by very
`light contact of the corner segments 28 thereagainst. As
`schematically illustrated in FIG. 5. a stent 52 is positioned
`in channel 30. which may have a sligrtly tapered entrance
`section 54. Where a banded stent 52. of the sort generally
`known as a “Wilder" stent is used. the interior wall of
`channel 30 (formed by corner segments 28). can be molded
`with a complementary series of shallow recesses 56 to
`further hold the stent in place.
`When a delivery system, such as the balloon catheter 18
`is inserted into channel 30, the device is in the configuration
`
`10
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`15
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`65
`
`Page 5 of 7
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`Page 5 of 7
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`

`

`5
`
`5,672,169
`
`6
`
`shown in FIG. 3. The stent 52 and channel 30 are sized to
`easily receive the selected delivery system 18. Where the
`device is transparent, the position of the stent and delivery
`system can be easily observed through he device. Once
`delivery system 18 is in the desired position.
`the two
`actuators 12 can be manually pressed toward each other with
`the fingers. As actuators 12 move together. sliding protu-
`berances 38 move together in elongated recesses 44 and
`elastic rods 46 are compressed along the line of pressure and
`enlarge in a direction transverse to the line of pressure. as
`seen in FIG. 4. Thus. channel 30 is uniformly reduced in
`cross sectional area. both as the space between blocks 22 in
`opposite actuators 12 decreases and as rods 46 force blocks
`22 together in the transverse direction. When the corner
`segments 28 come fully together.
`the channel has been
`reduced in size sufiiciently to properly crimp stent 52 around
`delivery system 18. The squeezing pressure on actuators 12
`is released and elastic forces in the rods 46. blocks 22 and
`guide members 14 combine to return the device to the
`configuration shown in FIG. 3. Delivery system 18. with
`stent 52 crimped in place is removed for use.
`While certain specific relationships. materials and other
`parameters have been detailed in the above description of
`preferred embodiments. those can be varied. where suitable,
`with similar results. Other applications. variations and rami-
`fications of the present invention will occur to those skilled
`in the art upon reading the present disclosure. Those are
`intended to be included within the scope of this invention as
`defined in the appended claims.
`I claim:
`
`3O
`
`35
`
`45
`
`50
`
`55
`
`1. A device for crimping a stent onto a catheter delivery
`system which comprises:
`a generally tubular channel having a longitudinal axis and
`having a circumferential wall formed by four spaced
`longitudinal segments of four spaced blocks;
`retention means along said generally tubular channel for
`retaining a stent against said circumferential wall;
`entrance means at an end of said generally tubular channel
`for allowing a delivery system to be inserted into said
`generally tubular channel and be positioned at a pre
`determined position relative to said retention means;
`pressure application means for forcing said four spaced
`longitudinal segments toward said longitudinal axis to
`compress and crimp said stent against said delivery
`system to form a unitary delivery system and stent
`assembly; and
`
`elastic means engaging said four blocks for releasing said
`compression and expanding said channel to allow said
`delivery system and stent assembly to be removed from
`said channel through said entrance means.
`2. The device according to claim 1 wherein each of said
`forn' spaced longitudinal segments is formed at a corner of
`one of four circumferentially spaced blocks.
`3. The device according to claim 2 wherein said pressure
`application means comprises two opposed actuators mov-
`able towards each other in a pressure application direction.
`each actuator elastically supporting adjacent pairs of said
`circumferentially spaced blocks.
`4. The device according to claim 3 further including
`elastic rod means mounted substantially parallel to said
`generally tubular channel between said blocks on said
`opposed actuators so that when said opposed actuators are
`moved together. said rods are compressed and rod thickness
`is decreased in the direction of pressure application and rod
`thickness is increased in a transverse direction. for moving
`
`said blocks to compress said generally tubular channel in
`said pressure application direction and said rod transverse
`thickness increase moves said blocks to compress said
`channel transverse to said pressure application direction.
`5. The device according to claim 1 wherein said retention
`means comprises shallow recesses in said circumferential
`wall configured to receive said stent therein.
`6. The device according to claim 1 wherein said pressure
`application means comprises two spaced actuators having
`ends. said elastic means comprises elastic guide means
`secured to said ends of said spaced actuators and further
`including end caps fastened to said elastic guide means
`opposite said spaced actuators for guiding said actuators for
`movement toward and away from each other along substan-
`tially straight lines.
`7. The device according to claim 1 wherein said device is
`made up of components at least one of which is formed from
`transparent plastic materials so that said stent and delivery
`system may be observed through said device.
`8. A device for installing a stent on a catheter which
`comprises:
`
`a substantially straight generally cylindrical channel hav-
`ing a central axis and a channel wall formed by four
`spaced corner segments of four concentrically spaced
`blocks;
`
`10
`
`15
`
`20
`
`25
`
`recesses in said channel wall configured to retain a stent;
`two adjacent said blocks elastically mounted on each of
`first and second actuator members having ends;
`two elastically deformable guide members elastically
`secured to ends of said first and second actuator mem-
`bers to permit said first and second actuator members to
`be manually moved toward each other;
`an end cap secured to each said guide member. each end
`cap including means for guiding guide member defor-
`mation and said first and second actuator member
`movement
`toward each other along substantially
`straight lines;
`elastic rod members between said first and second actua-
`tor members adjacent to said channel
`in operative
`engagement with said blocks;
`whereby movement of said first and second actuator
`members toward each other moves said block segments
`together along a line of pressure application and said
`rod members move said block segments together along
`a line transverse to said line of pressure application to
`crimp a stent in said channel around a catheter placed
`within said stent in said channel.
`9. The device according to claim 8 wherein each of said
`two adjacent blocks are joined to said actuator by a first web
`and together by a second web. each of said webs extending
`substantially parallel to said channel axis.
`10. The device according to claim 8 wherein said device
`is made up of components at least one of which is formed
`from transparent plastic materials so that of said stent and
`delivery system may be observed through said device.
`11. The device according to claim 8 further including a
`hole through each of said guide members and end caps
`coaxial with said channel.
`12. The device according to claim 8 wherein said
`actuators. guide members and end cap include cooperating
`pegs and recesses for bonding together for forming a unitary
`structure.
`
`Page 6 of 7
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`Page 6 of 7
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`

`

`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`PATENT NO.
`
`DATED
`
`:
`
`;
`
`5,67%169
`
`September 30, 1997
`
`INVENTOFKS) 1 Marcel A.E. Verbeek
`
`It is certified that error appears in the above-identified patent and that said Letters Patent is hereby
`corrected as shown below:
`
`Col. 2, Line 33:
`
`"beating"
`
`should be
`
`"bearing"
`
`
`
`Signed and Sealed this
`
`Seventeenth Day of February, 1998
`
`[Law
`
`BRUCE LEHMAN
`
`Arresting Oflicer
`
`Commissioner of Parems and Trademarkx
`
`Page 7 of 7
`
`Page 7 of 7
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`