United StateS Patent
`Ryan et al.
`
`[19]
`
`[54] STENT INTRODUCER SYSTEM
`Inventors: Carol A. Ryan; Kim T. Chiev, both of
`[75]
`Lowell, Mass.
`[73] Assignee: C. R. Bard, Inc. , Murray Hill, N. J.
`[21] Appl. No. : 480, 148
`Feb. 13, 1990
`[22] Filed:
`[51] Int. CLs
`[52] U. S. Cl.
`[58] Field of Search . . .
`
`A61M 29/00
`606/194; 623/1;
`604/96
`606/191, 194, 195, 192;
`604/96, 104; 623/1, 12
`
`[56]
`
`IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII[IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII
`US005108416A
`5, 108, 416
`[11] Patent Number:
`Apr. 28, 1992
`[45] Date of Patent;
`
`OTHER PUBLICATIONS
`Intraluminal Graft: A Pre-
`Palmaz et al. , "Expandable
`liminary Study", Radiology, 156: 73-77 (1985).
`Intraluminal Vascular
`et al. , "Expandable
`Palmaz
`Graft: A Feasibility Study", Surgery, 99: 199-204,
`(1986).
`Palmaz et al. , "Atherosclerotic Rabbit Aortas:Expanda-
`ble Intraluminal Grafting", Radiology, 160: 723 — 726,
`(1986).
`Wright et al. , "Percutaneous Endovascular Stents: An
`156: 69-72,
`Evaluation", Radiology,
`Experimental
`(1985).
`Wallace et al. , "Trachobronchial Tree: Expandable
`and Clinical Ap-
`Metallic Stents Used in Experimental
`plications", Radiology, 158: 309-312, (1986).
`et al. , "Stenosis of the Vena Cava: Pre-
`Charnsangavej
`liminary Assessment with Expandable Metallic Stents",
`Radiology, 161: 295-298, (1986).
`Intrahepatic Portacaval
`Rosch et al. , "Experimental
`Anastomosis: Use of Expandable Gianturco Stents",
`Radiology, 162: 481-485, (1987).
`(List contmued on next page. )
`Primary Examiner — John D. Yasko
`Assistant Examiner — William W. Lewis
`Attorney, Agent, or Firm — Wolf, Greenfleld & Sacks
`ABSTRACT
`[57]
`A system for introducing a stent into a patient at a site
`of stenosis is disclosed. The system comprises a balloon
`the balloon portion
`catheter having a stent surrounding
`is
`of the catheter. At least one stent-retaining means
`to at least one end of the balloon
`to
`located adjacent
`the
`in position on the catheter until
`the stent
`retain
`inflation of the balloon,
`the
`is inflated. Upon
`balloon
`stent is expanded and the retention means releases the
`is then deflated and the catheter
`is
`stent. The balloon
`removed from the patient, leaving the expanded stent in
`place.
`
`43 Claims, 16 Drawing Sheets
`
`10
`
`. . . 606/194
`
`. . . 606/194
`
`. . . 623/1
`
`. . . 623/1
`
`. . . 606/194
`
`. . . 623/1
`
`. . . 606/192
`
`. . . 623/1
`. . . 623/1
`
`References Cited
`U. S. PATENT DOCUMENTS
`.
`3/1970
`Silverman
`3, 502, 069
`2/1979
`Choudhury
`4, 140, 126
`Dotter .
`3/1985
`4, 503, 569
`.
`4/1985
`Spears
`4, 512, 762
`Maass et al. .
`11/1985
`4, 553, 545
`.
`12/1985
`Hammerslag
`4, 560, 374
`Gianturco
`4/1986
`4, 580, 568
`Rockey .
`2/1987
`4, 641, 563
`Wiktor . . . . . . . . . . . . . . . . . . .
`3/1987
`4, 649, 922
`.
`4/1987
`Wallsien
`4, 655, 771
`.
`4/1987
`Klein
`4, 660, 560
`Garza ei a1. .
`4, 665, 918
`5/1987
`Wiktor . . . . . . . . . . . . . . . . . . .
`7/1987
`4, 681, 110
`Wallsten et al. .
`3/1988
`4, 732, 152
`. . . . . . . . . . . . . . . . . . .
`3/1988
`Palmaz
`4, 733, 665
`.
`4/1988
`Palmaz
`4, 739, 762
`. . . . . . . . . . . . . . . .
`Kreamer
`4/1988
`4, 740, 207
`.
`8/1988
`Rosenbluth
`4, 762. 128
`Fischell ei al. .
`9/1988
`4, 768, 507
`.
`10/1988
`Palmaz
`4, 776, 337
`.
`12/1988
`Palmaz
`4, 793, 348
`Regan .
`1/1989
`4, 795, 458
`. . . . . . . . . . . . . .
`Gianturco
`1/1989
`4, 800, 882
`et al. .
`11/1989
`4, 878, 906
`Lindemann
`Martin et al. . . . . . . . . . . .
`11/1989
`4, 878, 908
`.
`Wiktor
`12/1989
`4, 886, 062
`1/1990
`Rosenbluth
`4, 893. 623
`3/1990
`Gianturco
`4, 907, 336
`.
`Strecker
`5/1990
`4, 922, 905
`Savin et al. . . . . . . . . . . . . .
`8/1990
`4, 950, 227
`. . . . . . . . . . . . . . . .
`9/1990
`Wallstein
`4, 954, 126
`Wiktor .
`11/1990
`4, 969, 458
`
`.
`
`.
`
`. . . . . . . . . . . .
`.
`
`18
`
`22
`
`12
`
`18
`
`14
`
`26
`
`28
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 1
`
`

`

`5, 108, 416
`Page 2
`
`OTHER PUBLICATIONS
`Sigwart et al. , "Intravascular Stents to Prevent Occlu-
`sion and Restenosis After Transluminal Angioplasty",
`NEJM, 316: 701-706, (1987).
`Intracoronary
`Schatz et al. , "Balloon-Expandable
`in the Adult Dog", Circulation 76: 450-457,
`Stents
`(1987).
`Roubin et al. , "Early and Late Results of Intracoronary
`
`in
`
`Stenting After Coronary Angioplasty
`Arterial
`Dogs", Circulation, 76: 891-897, (1987).
`Zollikofer et al. , "Endovascular Stenting of Veins and
`Grafts: Preliminary Clinical Experience", Radiology,
`167: 707-712, (1988).
`Barth et al. , "Flexible Tantalum Stents Implanted
`in
`Aortas and Iliac Arteries: Effects in Normal Canines",
`Radiology, 175: 91-96 (1990).
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 2
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 1 of 16
`
`5, 108, 416
`
`24
`
`Fig. 1A
`
`24
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 3
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 2 of 16
`
`15
`
`13
`
`15
`
`13
`
`17
`
`19
`
`17
`
`Fig. 2
`
`21
`
`12
`
`23
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 4
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 3 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 5
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 4 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 6
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 5 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 7
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 6 of 16
`
`5, 108, 416
`
`26
`
`34
`
`20
`
`40
`
`42
`
`38
`
`30
`
`36
`
`Fig. 7A
`
`34
`
`26
`
`20
`
`24
`
`30
`
`36
`
`Fig. 7B
`
`26 34
`
`20
`
`24
`
`30
`
`36
`
`Fig. 7C
`
`28
`
`40
`42
`
`28
`
`38
`
`40
`42
`
`38
`
`28
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 8
`
`

`

`U. S. Patent
`
`Apr. 2S, 1992
`
`Sheet 7 of 16
`
`5, 10S, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 9
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 8 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 10
`
`

`

`U. S. Patent
`
`Apr 28, 1992
`
`Sheet 9 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 11
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 10. of 16
`
`5, 108, 416
`
`U)
`Ll
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 12
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 11 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 13
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 12 of 16
`
`5, 108, 416
`
`26
`
`34
`
`20
`
`24
`
`30
`
`36
`
`Fig. 13A
`
`34
`
`26
`
`20
`
`24
`
`12 32
`
`30
`
`36
`
`26 34
`
`32
`
`30
`
`36
`
`Fig. 138
`
`20
`
`24
`
`38'
`
`28'
`
`28'
`
`38'
`
`41
`
`28'
`
`41
`
`38'
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 14
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 13 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 15
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 14 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 16
`
`

`

`U. S. Patent
`
`Apr. 2S, 1992
`
`Sheet 15 of 16
`
`5, 108, 416
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 17
`
`

`

`U. S. Patent
`
`Apr. 28, 1992
`
`Sheet 16 of 16
`
`5, 108, 416
`
`CD
`
`CD
`CD
`
`CV
`
`CA
`LL
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 18
`
`

`

`5, 108, 416
`
`STENT INTRODUCER SYSTEM
`
`FIELD OF THE INVENTION
`transluminal
`relates to percutaneous
`This invention
`a treated stenosis
`to stents for maintaining
`angioplasty,
`and to a delivery system for
`in an open configuration
`placing the stent in a patient's artery.
`BACKGROUND OF THE INVENTION
`angio-
`transluminal
`In recent years percutaneous
`plasty has become a common procedure for use in treat-
`(stenosis) in an artery. The treatment
`ing an obstruction
`results in improved blood flow and circulation
`through
`the treated artery.
`type of treatment
`in-
`the most common
`Although
`that is advanced
`volves the use of a balloon catheter
`is
`into the stenosis and
`the patient's arteries
`through
`to dilate
`the stenosis,
`then expanded under pressure
`region of
`the stenosed
`for enlarging
`other techniques
`the artery are under development.
`is
`The term "angioplasty" as used in this specification
`to mean not only the treatment of stenoses
`intended
`to encompass
`with a balloon catheter but is intended
`laser 25
`stenoses such as with
`other modes for treating
`catheters, atherectomy catheters or the like. When angi-
`oplasty is performed on the coronary arteries, the pro-
`tran-
`as percutaneous
`to generally
`is referred
`cedure
`(PTCA). PTCA is an
`coronary angioplasty
`sluminal
`surgery. The PTCA
`to coronary bypass
`alternative
`short duration and involves
`is of relatively
`procedure
`the femoral
`the skin and an artery (usually
`puncturing
`leg) to provide access to the pa-
`in the patient's
`artery
`for the PTCA catheter. The
`tient's arterial
`system
`the patient's arter-
`PTCA catheter is navigated
`through
`to be treated.
`the coronary artery
`it reaches
`ies until
`Typically, a patient undergoing PTCA will have a hos-
`pital stay of one or two days and will be able to resume
`full activity shortly thereafter. In contrast, treatment of
`a stenosed artery by coronary bypass surgery involves a
`very extensive and expensive operation with a long
`recuperative period.
`In a significant number of angioplasty cases, the re-
`gion of the artery where the angioplasty was performed
`inay reclose, either as a result of acute closure or as a
`result of restenosis. Acute closures are vascular emer-
`gencies in which the artery collapses during or immedi-
`ately after the angioplasty procedure. Such events are
`usually caused by damage to the artery or by a throm-
`bus. Restenosis, on the other hand, occurs at a much
`later date, usually some weeks or months after the pro-
`cedure. The restenosis may result from redevelopment
`cholesterol
`(e. g. , fatty material,
`of stenotic material
`deposits, etc. ) in the artery or from trauma to the inte-
`rior surfaces of the artery which occurs during catheter
`placement or withdrawal. Follow up data for PTCA
`that a small percentage of
`procedures has indicated
`patients develop acute closure within one hour after the
`PTCA treatment and approximately 30% redevelop a
`restenosis within six months after the PTCA treatment.
`treatment either by
`This restenosis will require further
`treatments or, pos-
`one or more subsequent angioplasty
`sibly, and ultimately by coronary artery bypass surgery.
`A number of techniques and devices have been pro-
`posed to solve the problem of restenosis. Among
`them
`tubular element, referred
`has been to insert a generally
`to as a stent, in the artery at the site of the stenosis after
`is performed. The tubular element
`is
`the angioplasty
`
`3p
`
`in a low profile condition (e. g. , a small effec-
`introduced
`is placed in the artery at
`tive cross-sectional diameter),
`into
`the region of the angioplasty and is then expanded
`engagement with the wall of the artery. For example,
`U. S. Pat. No. 4, 740, 207 to Kreamer discloses a gener-
`ally tubular stent having a spiral cross-section. The stent
`is delivered to the site of the angioplasty by mounting
`it
`on the balloon of a balloon catheter and then advancing
`the stent, into the artery.
`the balloon catheter, carrying
`lP When the balloon and stent are positioned at the site of
`to expand
`the
`is inflated
`the balloon
`the angioplasty,
`stent into engagement with the artery wall. The stent
`disclosed in the Kreamer patent incorporates a latching
`the stent locks in the expanded
`mechanism by which
`so that it will be securely retained within
`configuration
`then may be deflated
`the artery. The balloon catheter
`and removed from the patient. In placing the stent, it is
`that the delivery catheter have a low profile,
`important
`that it hold the stent securely in its collapsed configura-
`it enable easy expansion and release of the
`tion, that
`to be
`the delivery catheter
`it permits
`that
`stent and
`It is among the general objects of the inven-
`withdrawn.
`tion to provide such a delivery catheter.
`SUMMARY OF THE INVENTION
`the delivery cathe-
`In accordance with the invention,
`ter includes an elongate flexible shaft having a balloon
`mounted at its distal end. The balloon can be fabricated
`from a variety of polymeric materials such as polyethyl-
`(PET), polyolefin, nylon, or vinyl
`ene terephthalate
`is mount-
`with polyolefins being preferred. The stent
`able, in a contracted configuration on the balloon. The
`suffi-
`low pressure
`balloon may be expanded under
`35 ciently to engage the interior of the stent. The balloon is
`to a diameter to cause the stent to expand into
`inflatable
`firm engagement with the artery wall. In order to se-
`cure the stent on the catheter during delivery and to
`facilitate release of the stent, the delivery catheter
`is
`4p provided with at least one outer end cap located at the
`proximal end of the balloon. Another end cap may be
`located at the distal end of the balloon. The end caps
`it from
`engage and secure the mounted stent to prevent
`slipping off of the balloon. The outer end
`inadvertently
`is in-
`the balloon
`45 cap is resilient and yieldable. When
`flated to expand and place the stent, the end cap resil-
`releases the stent in re-
`iently yields and automatically
`to the balloon expansion. After the stent has
`sponse
`is collapsed and the end cap
`been placed, the balloon
`5p will return, under the influence of its own resilience, to
`configuration. When contracted,
`the
`the contracted
`balloon and the end cap have a profile smaller than the
`interior diameter of the expanded stent so that the deliv-
`the stent.
`through
`ery catheter can be withdrawn
`to
`the general objects of the invention
`It is among
`provide an improved stent delivery system for use as an
`adjunct to angioplasty.
`is to provide an im-
`Another object of the invention
`proved stent delivery system that is of simple construc-
`60 tion.
`A further object of the invention
`is to provide an
`improved stent delivery system that is easy to use and
`operate.
`is to provide a stent
`Another object of the invention
`65 delivery system that includes a catheter having at least
`the
`to engage
`retaining element adapted
`one resilient
`the stent is mounted on a catheter and to
`stent when
`release the stent when the stent is expanded.
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 19
`
`

`

`5, 108, 416
`
`A further object of the invention
`is to provide an
`stent delivery system having at least one re-
`improved
`is self-
`the retainer
`tainer as described above in which
`to facilitate withdrawal of the delivery sys-
`collapsing
`tem
`
`DESCRIPTION OF THE DRAWINGS
`The foregoing and other objects and advantages of
`the invention will be appreciated more fully from the
`thereof, with reference to
`following further description
`the accompanying drawings wherein:
`FIGS 1A and 1B are illustrations of one embodiment
`of a stent;
`FIG. 2 is an illustration of a second embodiment of a
`stent;
`FIG. 3 is a cross-sectional view of one embodiment of
`in the stent delivery system;
`a catheter shaft useful
`FIG. 4 is an illustration of a stent delivery system
`in
`accordance with the invention prior to expansion of the
`stent;
`FIG. 5 is an illustration of the stent delivery system
`with the stent in the expanded configuration;
`FIG. 6 is an illustration of the stent delivery system
`upon withdrawal of the introducer;
`FIGS. 7A — 7C are illustrations of the stent delivery
`the operation of the stent and end caps;
`system showing
`FIGS. 8A and 8B are illustrations of one embodiment
`of an end cap having a weakened
`region provided with
`slits;
`FIGS. 9A and 9B are illustrations of an embodiment
`of an end cap having a weakened
`region containing a
`bulge;
`FIGS. 10A and 10B are illustrations of a second em-
`region con-
`bodiment of an end cap having a weakened
`taining a bulge;
`FIGS. 11A and 11B are illustrations of a third em-
`region con-
`bodiment of an end cap having a weakened
`taining a bulge;
`FIG. 12 is an illustration of a second embodiment of
`the stent delivery system employing a modified end cap
`at the distal end of the introducer;
`FIGS. 13A — 13C are illustrations of the second em-
`bodiment of the stent delivery system showing the oper-
`ation of the stent and the end caps; and
`FIG. 14 is an illustration of a third embodiment of the
`stent delivery system employing a proximal end cap and
`a retractable sheath.
`FIG. 15 is an illustration of a fourth embodiment of
`the stent delivery system showing a delivery catheter
`having two interior end caps mounted within an inflated
`balloon.
`FIG. 16 is an illustration of the fourth embodiment of
`the stent delivery system showing a delivery catheter
`having a deflated balloon prior to stent loading.
`FIG. 17 is an illustration of the fourth embodiment of
`the stent delivery system showing a stent loaded onto
`the delivery catheter.
`DETAILED DESCRIPTION OF THE
`INVENTION
`The stent delivery system of the present system can
`be used to place a stent at a site of stenosis either subse-
`simultaneously with a
`quently, or as an alternative,
`a balloon dilatation
`dilatation procedure
`employing
`catheter. In the former case, a balloon dilatation cathe-
`to
`to the stenosis site and positioned
`ter is navigated
`the stenosis. The balloon then
`place the balloon within
`is inflated to press against the stenosis, thereby causing
`
`5
`
`15
`
`to be enlarged. The
`the stenosis
`through
`the
`lumen
`and exchanged for
`dilatation catheter then is withdrawn
`the stent delivery catheter. The delivery catheter
`is
`to the site of the dilatation
`to place the stent
`navigated
`in the dilated stenosis and the stent then
`is expanded.
`the
`The delivery catheter
`leaving
`is withdrawn,
`then
`site. Alterna-
`in place at the treatment
`stent
`expanded
`in the latter case, a separate balloon dilatation
`tively,
`catheter is not used. Rather, the stent delivery catheter
`the unex-
`to the stenosed site to position
`10 is navigated
`is then ex-
`panded stent across the stenosis. The stent
`dilating the stenosis and
`panded, thereby simultaneously
`the stent. The delivery catheter then is with-
`expanding
`the expanded stent in place.
`drawn,
`leaving
`The stent introducer of the present
`invention can be
`used with a variety of expandable
`stents, both those
`in the art and those yet to be developed. Ac-
`known
`cordingly, stents formed of rolled rectangular polymer
`incor-
`in the previously
`sheets such as those described
`20 porated U. S. Pat. No. 4, 740, 207 to Kreamer, as well as
`stents formed of curved sections of metal wire such as
`in U. S. Pat. No. 4, 800, 882 to Gianturco
`those described
`to be
`(incorporated herein by reference) are intended
`the present
`for use in conjunction with
`contemplated
`25 invention,
`in U. S. Pat. No.
`The stent described by Kreamer
`in FIGS. 1A and 1B. The stent 24,
`4, 740, 207 is shown
`tube made of
`resilient
`generally comprises a semi-rigid,
`residence within a
`for long-term
`suitable
`a material
`state, the tube is
`30 blood vessel. In its relaxed, unexpanded
`generally cylindrical having a relatively small diameter
`is a section of a spiral. One
`and a cross section which
`the outer portion of the
`edge of the tube 4, preferably
`ledge 6. Upon expansion of that
`spiral, has a retaining
`tube becomes partially unrolled.
`35 stent, the cylindrical
`This results in a cylinder having a larger diameter. If the
`inner
`the formerly
`sufficiently,
`is expanded
`cylinder
`region of the spiral 2 will be engaged by the retaining
`in its expanded
`the cylinder
`locking
`ledge 6, thereby
`40 configuration.
`in U. S. Pat. No.
`The stent described by Gianturco
`in FIG. 2. The stent 24 generally
`4, 800, 882 is shown
`comprises a length of wire having a plurality of curved
`circular
`sections 11 that are formed
`into a generally
`45 configuration. Adjacent curved sections are joined by a
`bend or cusp 13, so that a series of alternating opposing
`loops 15, 17 are formed. A loop 19 is formed at each free
`end of the wire stent in order to shield the wire end. The
`resulting stent has a cylindrical shape with a longitudi-
`through which'a deflated balloon catheter
`50 nal opening
`loops are tightly con-
`can be inserted. The opposing
`tracted around the balloon so that the cylindrical shape
`region in which portions of adjacent
`has an overlapping
`is in-
`the balloon
`overlap. When
`loops longitudinally
`relative
`55 flated, adjacent loops diverge circumferentially
`re-
`the overlapping
`to each other, thereby decreasing
`the diameter of the cylindrical
`increasing
`gion while
`shape. The expanded diameter of the stent is retained by
`a plastic deformation of the wire that occurs during
`the
`has been
`60 expansion. Once the expanded configuration
`the balloon catheter is withdrawn.
`achieved,
`In one embodiment, a bioresorbable polymeric mate-
`rial can be used to form a stent which is otherwise simi-
`in the previously de-
`to that shown
`lar in construction
`is desir-
`65 scribed Kreamer patent. Such an embodiment
`it will help to maintain patency of the
`able because
`blood vessel for an extended period of time while still
`the patient.
`fixture within
`being less than a permanent
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 20
`
`

`

`5, 108, 416
`tion, they have a cross-sectional diameter which
`is less
`system of the
`the stent delivery
`In a broad sense,
`than that of the interior diameter of the expanded stent.
`for inserting a
`present invention comprises an apparatus
`The delivery catheter can then be withdrawn
`from the
`the stent at a site of
`stent into a patient and expanding
`patient without affecting the position of the stent. Such
`for
`includes a means
`the apparatus
`stenosis, wherein
`allows the delivery catheter to be com-
`the 5 a withdrawal
`the stent. More specifically,
`retaining
`releaseably
`the
`the patient while
`leaving
`from
`removed
`apparatus comprises a modified dilatation catheter hav-
`pletely
`expanded stent at a desired location within
`the patient.
`ing an expandable balloon at its distal end and at least
`The operation of the end caps is more clearly shown
`one flexible end cap which serves to retain the stent on
`in FIGS. 7A-7C. FIG. 7A shows
`the stent delivery
`the balloon until the stent is expanded at a desired loca-
`stent prior to placement of the
`10 system and a mounted
`the patient.
`tion within
`stent at the stenosis. The balloon 20 is deflated via infla-
`in FIG. 3, the catheter
`shown
`In one embodiment,
`sleeve 32
`tion lumen 30. End cap 26 has a mounting
`infla-
`lumen 21, and a balloon
`shaft 12 has a quidewire
`the
`to the catheter shaft at a region adjacent
`tion lumen 23. The shaft is constructed of a polyolefin
`attached
`proximal end of balloon 20. The mounting sleeve can be
`vinyl acetate being
`and ethylene
`with polyethylene
`to be lim- 15 attached to the catheter shaft using any of a variety of
`preferred. The catheter shaft is not intended
`bonding methods. These include, but are not limited to,
`embodiment of FIG. 3. Rather,
`ited to the dual-lumen
`adhesive bonding, heat bonding and ultrasonic bonding.
`lumens as well as catheters
`catheters having coaxial
`to prevent
`The bond must provide adequate strength
`having three or inore lumens can be used as the delivery
`from the cathe-
`sleeve 32 from detaching
`the mounting
`such
`single lumen embodiments,
`catheter. Additionally,
`systems can be used with the present 20 ter shaft when compression forces are applied to the end
`as balloon-on-wire
`cap. An annular socket 34 defined by the end cap sur-
`invention.
`rounds the balloon 20 without contacting it. An annular
`is shown
`The operation of the stent delivery system
`the balloon and
`space 36, defined by the area between
`in FIGS. 4-6. In FIG. 4, the system comprises
`generally
`the annular socket 34 of end cap 26, serves to capture
`represented as 10, corn-
`a dilatation catheter, generally
`prising a multi lumen catheter shaft 12, having a balloon 25 and retain the proximal end of the stent 24.
`sleeve 38 at-
`Similarly, end cap 28 has a mounting
`20 (concealed), mounted at the distal end of the shaft.
`tached to the shaft at a region adjacent the distal end of
`from a variety of poly-
`The balloon can be fabricated
`sleeve 38 is
`(i. e. vinyl, various polyolefins, PET,
`balloon 20. As with end cap 26, mounting
`meric materials,
`to the catheter shaft using adhesives, heat,
`attached
`nylon), with polyolefins being preferred. The catheter
`lumen 30 ultrasonic bonding or any of a variety of methods
`shaft has a pair of lumens
`including an inflation
`in the art. An annular socket 40 defined by the
`known
`the balloon and a guidewire
`that communicates with
`it. An
`end cap surrounds balloon 20 without contacting
`flexible
`to individual
`lumen. The lumens are connected
`the bal-
`annular space 42, defined by the area between
`legs 14, 16 through Y-fitting 22. The proximal
`tubular
`loon and the annular socket 40, serves to capture and
`luer fitting
`end of each leg can terminate
`in a standard
`18. In this example, leg 14 is in communication with the 35 retain the distal end of the stent 24. As can be seen in
`the ends of the
`FIG. 7A, the end caps 26, 28 surround
`in the catheter shaft which serves to
`lumen
`inflation
`stent and serve to prevent axial movement of the stent
`enable inflation and deflation of the balloon 20, and leg
`the proximal end or distal end of the
`toward either
`16communicateswiththeguidewirelumenwhichexits
`delivery catheter. Thus, the catheter can be inserted
`the catheter shaft at its distal tip. A stent 24 in its col-
`the stent from its posi-
`in 40 into a patient without displacing
`is retained
`the balloon and
`lapsed state surrounds
`tion about the balloon.
`position by end caps 26, 28 which receive and capture
`Once the stent has been placed in a stenosis or dilated
`the proximal and distal ends of the stent. The end caps
`in FIG. 7B.
`is inflated as shown
`the balloon
`serve to prevent axial displacement of the stent as the
`stenosis,
`The radial expansion of the balloon 20 imparts a corre-
`delivery system and stent are guided through a patient.
`to the stent 24 while simulta-
`The end caps can be formed of any of a variety of resil- 45 sponding
`radial expansion
`the annular sockets 34, 40 of the end
`polyester elasto-
`neously urging
`including polyurethane,
`ient polymers
`caps 26, 28 away from the stent and toward mounting
`(SEBS) block
`mers, styrene-ethylene-butadiene-styrene
`sleeves 32, 38 of the end caps. In so doing, the end caps
`latexes and silicones. End caps formed of a
`copolymers,
`release the stent 24.
`26, 28 retractably
`by ATOCHEM,
`(marketed
`block amide
`polyether
`in FIG. 7C the balloon is deflated,
`Finally, as shown
`the trademark PEBAX), have been found 50
`INC. under
`to the
`resiliently
`and the balloon and end caps return
`the end caps may
`to be particularly useful. Additionally,
`in FIG. 7A. The stent remains
`in
`shown
`be coated on the inner or outer diameters' or both with
`configuration
`its expanded position, having an interior diameter corre-
`a lubricious material such as a silicone. Such a coating
`to the outer diameter of the bal-
`sponding substantially
`facilitate stent release or tracability.
`would respectively
`inflated. The interior diameter of the ex-
`As can be seen in FIG. 5, upon inflation of the balloon 55 loon when
`is greater than the outer diame-
`Inflation of the
`panded stent, however,
`20, the stent 24 is radially expanded.
`is de-
`ter of the end caps or balloon when the balloon
`balloon 20 also causes end caps 26, 28 to be urged radi-
`flated, and this configuration allows the delivery cathe-
`fashion from the
`ally and axially away, in umbrella-like
`from the stent without causing the
`ter to be withdrawn
`center of the balloon, so that they retract and release the
`the portions of the end 60 stent to be moved from its expanded position. Thus, the
`this motion,
`stent 24. During
`from
`deliveiy catheter can be completely withdrawn
`caps covering the stent are expanded radially to assist in
`the patient while leaving the expanded stent in place.
`in FIG. 6,
`release of the stent. Subsequently,
`as shown
`the end caps 26, 28 contain a
`In one embodiment,
`the balloon 20 is deflated and the end caps 26, 28 return
`weakening means for assisting retraction and release of
`to their initial non retracted position. The stent 24 re-
`this weakening means
`mains in its expanded state, having an interior diameter 65 the stent. In one embodiment
`comprises at least one axial slit in a center region of the
`the outer diameter of the inflated
`which approximates
`sleeve and the
`the mounting
`end cap located between
`balloon 20. Once the balloon 20 and end caps 26, 28
`the balloon. In a pre-
`annular socket which surrounds
`configura-
`to their initial, non-retracted
`have returned
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1021 - Page 21
`
`

`

`in FIGS. 8A — SB, four axial
`ferred embodiment,
`shown
`slits are evenly spaced about the end cap between
`the
`sleeve and the annular socket with a spacing
`mounting
`of approximately 90' between each. These slits allow
`the center. region of the end caps to collapse axially and
`sockets are urged
`the annular
`bulge outwardly when
`toward their respeciive mounting sleeves by the inflated
`balloon.
`More particularly, FIG. SA shows an end cap 26
`sleeve 32 and an annular socket 34. &0
`having a mounting
`sleeve and the socket is a weak-
`Between the mounting
`slits 35, (of which
`ened area 33 having four equidistant
`in the figure). Upon application of
`only two are shown
`a radial force to the annular
`socket 34, such as will
`occur upon inflation of the balloon, the socket is pushed
`the weakened
`sleeve 32, causing
`toward
`the mounting
`from the centerline of the
`area 33 to bulge outwardly
`end cap. The retraction of the end cap caused by the
`socket to release
`radial force causes the annular
`the
`stent. This effect can be seen in FIG. 8B. The weakened 20
`area 33 enhances the ease with which the annular socket
`34 can be pushed toward the mounting sleeve and there-
`fore eases release of the stent from the socket.
`region of the
`the weakened
`In another embodiment,
`sleeve and the
`the mounting
`end cap located between
`is formed
`the balloon
`annular socket which surrounds
`interior diameter
`to have a larger
`the mounting
`than
`this larger interior
`sleeve. In a preferred embodiment,
`is provided as a preformed bulge which allows 30
`diameter
`the annular socket of the cap surrounding
`the balloon to
`the bal-
`sleeve when
`toward
`be pushed
`the mounting
`loon is inflated. As before, the retraction of the end cap
`caused by the radial force causes the annular socket to
`release the stent. An end cap of this design is shown
`in 35
`FIGS. 9A-9B. FIG. 9A is a cross-sectional elevation of
`the basic end cap. As can be seen in FIG. 9A, a bulge 60,
`sleeve 32 of the end
`is located between
`the mounting
`socket 34 of the end cap. The
`the annular
`cap and
`to the catheter shaft at a 40
`sleeve
`is affixed
`mounting
`region adjacent to the balloon and the annular socket 34
`the balloon and, prior to expansion,
`the stent
`surrounds
`24. The bulge 60 provides a region of lessened
`resis-
`tance to axial contraction of the end cap and thereby
`facilitates release of the stent 24 by the annular socket 45
`is inflated. FIG. 9B
`34 of the end cap when the balloon
`is an end view of the end cap of FIG. 9A. As can be seen
`in FIG. 9B, the interior diameter of the annular socket
`34 of the end cap is symmetrical, decreasing
`radially
`the proximal end of the end cap.
`toward
`In another embodiment of the end cap, shown
`in
`FIGS. 10A-10B, the interior diameter of the annular
`socket 34' of the end cap is asymmetrical. Such a config-
`to minimize contact of the interior
`uration
`is intended
`surface of the annular socket 34' of the end cap with the 55
`lowering friction between
`the annular
`stent 24, thereby
`socket 34' of the end cap and the stent 24. This configu-
`ration increases the ease of release of the stent by lower-
`to retraction of the annular
`resistance
`ing frictional
`socket 34' of the end cap. As in the embodiment of the 60
`in FIGS. 9A and 9B, the mounting
`end cap shown
`sleeve of the end cap and the bulge 60 are unchanged.
`FIG. 10B shows one embodiment of an end cap having
`inner diameter of its annular socket 34'.
`an asymmetrical
`In FIG. 10B the interi