_
`Umted States Patent
`
`[19]
`
`USOOS364354A
`[11] Patent Number:
`
`5,364,354
`
`
`
`Walker et a1. Nov. 15, 1994 [45] Date of Patent:
`
`
`
`[54]
`
`[75]
`
`giLCEOAggECAABTIgEEINEgEGRATED'WIRE
`.
`Inventors: Blair D. Walker, Long Beach; Sheryl
`W. Higgins, Silverado, both of Calif.
`
`[73] Assignee: Baxter International Inc., Deerfield,
`Ill.
`
`[21] Appl. No.: 970,581
`[221 Filed:
`091- 22a 1992
`_
`_
`Rdated U-S- Application Data
`Continuation of Ser. No. 690,447, Apr. 24, 1991, aban-
`doned_
`
`[63]
`
`Céis """"""""""""""""""""
`. ..................................... ..
`.
`.
`[58] Flew 0f search """""""""
`[56]
`References Cited
`D UMENTS
`.
`.
`U S PATENT 0C
`4x9947013
`2/1991 SaPer '
`.
`5,045,061
`9/1991 Seifert et a1.
`5,102,390 4/1992 Crittenden et a1.
`5,135,487
`8/1992 Morrill et al.
`.
`5 135 494
`8/1992 Engelson et a1.
`5,171,221 12/1992 Samson .
`5,192,295
`3/1993 Danforth et a1.
`
`.
`
`.
`
`.
`
`.
`
`
`
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`‘— _—_—_—
`. —- -— ~_ ~- — 1
`
`'-- -— -- —
`I
`‘———___‘““—-—‘‘_‘—‘—’
`
`
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 1
`
`FOREIGN PATENT DOCUMENTS
`3935579 10/1989 Germany .
`w092/08510 5/1992 WIPO .
`
`Primary Examiner—John D. Yasko
`Attorney, Agent, or Firm—Debra D. Condino; Raymond
`Sun
`
`ABSTRACI‘
`A fully exchangeable integrated-wire dilation catheter
`for performing angioplasty is disclosed having a flexible
`small diameter guide wire provided with an enlarged
`diameter distal end portion and a flexible elongated
`tubular shaft with at least one dual function fluid con-
`ducting lumen adapted to receive the guide wire ex-
`tending therethrough. The distal end of the tubular
`shaft is connected to the proximal end of an expandable
`balloon provided with a coaxially aligned distal orifice
`having means for releasably engaging the enlarged dis~
`tal end portion of the guide wire in sealing relationship.
`In a referred embodiment the sealin means is a flexi-
`P
`.
`.
`g .
`ble sleeve extending from the distal orifice of the ex-
`pandable balloon and dimensioned to slidineg engage
`the correspondingly sized enlarged distal end portion of
`the guide wire. Associated procedures for utilizing the
`dilation catheter are also d1801086d.
`.
`-
`21 Claims, 4 Drawmg Sheets
`
`,
`
`’
`
`
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 1
`
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`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 2
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 2
`
`
`
`
`

`

`US. Patent
`
`Nov. 15, 1994
`
`Sheet 2 of 4
`
`5,364,354
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`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 3
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 3
`
`
`

`

`US. Patent
`
`Nov. 15, 1994
`
`Sheet 3 of 4
`
`5
`
`,364,354
`
`
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 4
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 4
`
`

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`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 5
`
`

`

`1
`
`5,364,354
`
`
`
`EXCHANGEABLE INTEGRATED-WIRE
`BALLOON CATHETER
`
`This application is a continuation of Ser. No.
`07/690,447 filed Apr. 24, 1991 now abandoned.
`FIELD OF THE INVENTION
`
`The present invention relates in general to the field of
`dilation or balloon catheters employed in the treatment
`of vascular diseases. More particularly, the present in-
`vention relates to an integrated or fixed-wire balloon
`catheter assembly which can be positioned quickly and
`easily for use in opening vascular stenoses yet which
`provides the additional advantage of rapid balloon re-
`moval or replacement while retaining wire guided ac-
`cess to the stenotic lesion.
`
`5
`
`10
`
`15
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`BACKGROUND OF THE INVENTION
`
`20
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`25
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`3O
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`35
`
`Over the last decade the medical procedure known as
`angioplasty has become widely accepted as a safe and
`effective method for treating various types of vascular
`diseases. For example, angioplasty is widely used for
`opening stenoses throughout the vascular system and
`particularly for opening stenoses in coronary arteries.
`At present, the most common form of angioplasty is
`called percutaneous transluminal coronary angioplasty
`(PTCA). This procedure utilizes a dilation catheter
`having an inflatable balloon at its distal end. Using a
`fluoroscope and radiopaque dyes for visualization the
`distal end of the dilation catheter is guided into position
`through a guide catheter and across the stenosis and the
`balloon is inflated for a brief duration to open the artery
`and establish adequate blood flow. Typically, inflation
`of the balloon is accomplished by supplying pressurized
`fluid through an inflation lumen in the catheter which is
`connected to an inflation apparatus located outside the
`patient’s body. Conversely, applying a negative pres-
`sure to the inflation lumen collapses the balloon to its
`minimum dimension for initial placement or removal of 40
`the balloon catheter within the target blood vessel.
`In the past years a number of balloon catheter designs
`have been developed which have contributed to the
`safety and acceptability of PTCA and similar medical
`procedures. The most common design is known as an
`“over-the-wire” balloon catheter. This prior art device
`typically utilizes a relatively large lumen for passage of
`a guide wire and injection of angiographic visualization
`dye to assist in the placement of the device. A second
`parallel lumen is provided for inflation and deflation of
`the balloon. Typically, a steerable guide wire is posi-
`tioned within the larger lumen and the entire assembly
`is maneuvered into an initial position within the target
`artery through a previously positioned large diameter
`guide catheter. Once near the site of the stenoses the
`guide wire can be rotated and axially extended or re—
`tracted into position across the lesion. The catheter is
`subsequently advanced along the guide wire to position
`its balloon end across the lesion prior to inflation of the
`balloon and dilation of the stenosis.
`Though successful at opening stenotic lesions, these
`dual
`lumen catheters are relatively bulky and stiff
`which makes their use difficult for any lesions except
`those that are proximal and localized in nontortuous,
`easily accessible vessels. Moreover, these early design
`over-the-wire balloon catheters require an additional
`implanting physician or assistant to control the guide
`wire during positioning of the assembly because cathe-
`
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`2
`ter and wire movement are independent of one another.
`This complex coordinated activity requires both experi-
`ence and skill and may result in a slower insertion pro—
`cedure than desired.
`
`An alternative over-the-wire catheter assembly uti-
`lizes a non-removable guide wire that allows for longi-
`tudinal or axial movement. However, this design has a
`significant drawback because the entire non-removable
`guide wire catheter assembly must be removed to ac-
`complish replacement or exchange of the balloon. In
`some cases of PTCA it is necessary to replace the bal-
`loon with one of different diameter or configuration
`following the initial dilation. Additionally, cases of
`acute reclosure have been noted where the lesion re-
`closes following dilation and removal of the balloon
`catheter. This alternative system increases the difficul-
`ties of these subsequent procedures by requiring that the
`replacement catheter renegotiate the entire placement
`path without the advantage of a guide wire.
`A “monorail” variant of the standard balloon-over-a—
`wire system also has been developed where only the
`distal portion of the balloon catheter tracks over the
`guide wire. This system utilizes a conventional inflation
`lumen and a relatively short guiding or through lumen
`at the distal end. Its principal benefits are the reduction
`of frictional drag over the length of the externally lo-
`cated guide wire and the ease of balloon exchange. It
`provides the ability to recross an acutely closed vessel
`or to exchange balloons without removing the guide
`wire. However, a disadvantage of this design is the
`increased difficulty in steering the guide wire because
`the guide wire is not supported by the balloon catheter.
`Additionally, the dual lumen distal design produces a
`larger profile and shaft size.
`Another prior art innovation in dilation catheter de-
`sign is the “fixed-wire” or integrated “balloon-on—a-
`wire” dilation catheter. These single lumen designs
`utilize a relatively narrow wire positioned within the
`inflation lumen and permanently fixed to the distal end
`of the balloon. This produces a low-profile assembly
`which is able to cross severely narrowed lesions and to
`navigate tortuous vascular pathways. Additionally, the
`fixed guide wire bonded at the distal end of the balloon
`improves the steerability and pushability of these de-
`signs which enhances their maneuverability. The thin
`shaft design also improves coronary visualization and
`enables all but the tightest critical lesions to be crossed.
`However, though able to provide relatively quick and
`simple balloon placement as well as providing access to
`lesions otherwise unsuitable for PTCA, balloon-on-a—
`wire systems sacrifice the ability to maintain guide wire
`position across the lesion when exchanging balloons or
`the safety advantage of being able to recross an acutely
`closed vessel without repositioning the entire assembly.
`Accordingly, it is an object of the present invention
`to provide a balloon-on-a—wire dilation catheter which
`incorporates all of the benefits of a small diameter fixed
`wire system yet allows for removal, reengagement or
`replacement of the balloon while leaving the guide wire
`in place to preserve an easily renegotiated path along
`the blood vessel being treated.
`It is an additional object of the present invention to
`provide an integrated-wire dilation catheter offering an
`extremely low profile and a small shaft size to facilitate
`maneuverability and placement of the catheter as well
`as to provide it with the ability to negotiate tortuous
`vessels and to pass highly stenosed lesions.
`
`
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 6
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 6
`
`

`

`3
`It is a further object of the present invention to pro-
`vide an integrated-wire balloon catheter having a steer-
`able guide wire releasably fixed inside the catheter to
`provide enhanced torqueability, pushability, and ma-
`neuverability in order to facilitate the rapid, single oper-
`ator placement and positioning of the assembly.
`SUMMARY OF THE INVENTION
`
`These and other objects are achieved by the ex-
`changeable integrated-wire balloon catheter of the pres-
`ent invention which, in accordance with broad struc-
`tural aspects thereof, includes at least a single-lumen
`balloon catheter having a seal at its distal end which
`releasably engages the enlarged distal end portion of a
`flexible guide wire running the length of the catheter.
`This unique construction allows rotational and longitu-
`dinal movement of the guide wire relative to the balloon
`catheter where desired and, if necessary, allows the
`catheter to be removed and reengaged or fully ex-
`changed over the guide wire. Further, additional lu-
`mens may be incorporated into the basic catheter design
`to carry drugs, blood, fluids and the like or to allow
`blood to passively perfuse the distal artery during bal-
`loon inflation.
`More specifically, the flexible guide wire of the pres-
`ent invention is formed of metal, polymeric material or
`a combination of both and is provided with a relative
`small cross-sectional diameter to increase its flexibility
`and to reduce the overall cross-sectional profile of the
`dilation catheter assembly. However, unlike prior art
`guide wire designs the distal end portion of the guide
`wire steps up to a larger outer diameter. The catheter
`assembly of the present invention positions the small
`diameter proximal portion of the guide wire along the
`length of the axial lumen of the elongated tubular shaft
`of the balloon catheter and through the balloon itself.
`The expandable balloon portion of the catheter is con-
`nected to the distal end of the tubular shaft in a sealing
`or fluid conducting arrangement with the axial lumen.
`The distal end of the expandable balloon is provided
`with an orifice that is coaxially aligned with the axial
`lumen and adapted to receive or conduct the guide
`wire. The distal orifice in turn is provided with means
`for releasany engaging the enlarged diameter distal end
`portion of the guide wire in a sealing relationship to
`allow for pressurization and inflation of the balloon and
`to fix the wire within the catheter in order to facilitate
`maneuvering the assembly during placement.
`In this manner, the present invention combines the
`functions of fluid conducting and guide wire transmittal
`in a single lumen as opposed to the prior art dual-lumen
`balloon catheter designs. This unique construction pro-
`vides an exchangeable balloon catheter having an ex-
`ceptionally small insertion profile and all of the advan-
`tages previously associated with non-exchangeable fix-
`ed»wire catheters; yet it also provides the advantage of
`the ability to leave its guide wire in position across a
`vascular lesion during balloon exchange or removal.
`In a preferred embodiment of the present invention
`the means for releasany engaging the enlarged diame-
`ter distal end portion of the guide wire in sealing rela-
`tionship is a resilient sleeve which extends from the
`distal orifice of the expandable balloon. This sleeve is
`dimensioned to slide over the enlarged diameter distal
`end portion of the guide wire as the catheter is ad-
`vanced distally along the wire. Preferably, the distal
`portion of the wire is formed to have a smoothly sur-
`faced, cylindrical cross section as this construction al—
`
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`5,364,354
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`4
`lows the resilient sleeve to seal against the distal end
`portion of the guide wire. Additionally,
`it provides
`sufficient freedom of movement to allow the guide wire
`to rotate in place in order to facilitate the manipulation
`of the balloon catheter into position within a vascular
`pathway.
`Sliding the catheter proximally relative to the inter-
`nal guide wire (or vis versa) slips the resilient sleeve off
`of the enlarged diameter distal end portion of the guide
`wire onto the smaller diameter proximal portion of the
`wire. The unseating of the resilient sleeve from the
`enlarged diameter distal end portion of the guide wire
`breaks the seal at the distal catheter end. In this position
`the guide wire can be advanced axially along the longi—
`tudinal axis of the catheter to cross narrow or irregular
`lesions or to follow a tortuous vascular pathway. Simi-
`larly, following dilation the guide wire can be left in
`place across the stenotic lesion as the disengaged bal-
`loon is partially withdrawn along the wire to verify
`dilation and blood flow. If necessary, the balloon can be
`readvanced distally along the wire until the resilient
`sleeve sealingly reengages the distal end portion of the
`guide wire. Following reengagement the balloon can be
`reinflated. As those skilled in the art will appreciate, a
`complete exchange of the balloon is possible without
`retracking the pathway utilizing the same general pro-
`cedure along the positioned guide wire.
`To facilitate visualization of the guide wire and bal-
`loon catheter during angioplasty the apparatus of the
`present invention is preferably provided with one or
`more radiopaque markers. Typically, these markers are
`formed of small coils, strips or spheres of gold, platinum
`or other dense, relatively inert metal. In one embodi-
`ment of the present invention a radiopaque spring coil
`of flexible wire is provided distally to the enlarged
`diameter distal end portion of the guide wire. Similarly,
`in alternative embodiments of the present invention
`radiopaque markers are located along the guide wire at
`positions proximal to the enlarged distal end portion of
`the wire. It is also contemplated as being within the
`scope of the present invention to position radiopaque
`markers on the balloon catheter to enable the coronary
`physician to visualize the placement of the balloon rela-
`tive to the guide wire and stenotic lesion.
`Other features and advantages of the present inven-
`tion will become apparent from the following detailed
`description, taken in conjunction with the accompany—
`ing drawings which illustrate, by way of example, the
`principals of the present invention.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`illustrating additional features of the present invention.
`
`FIG. 1 is a partial fragmentary view in elevation of an
`integrated-wire dilation catheter illustrating the princi-
`pals of the present invention.
`FIG. 2 is an enlarged cross-sectional view of the
`distal portion of the balloon catheter of FIG. 1.
`FIG. 3 is a partial sectional View of the distal portion
`of the balloon catheter of FIG. 2 shown in a collapsed
`modified position.
`FIG. 4 is a sectional view of the distal portion of an
`alternative embodiment of the present invention illus-
`trating additional features thereof.
`FIG. 5 is an enlarged partial sectional view of an
`alternative embodiment of the distal portion of the
`guide wire of the present invention.
`FIG. 6 is an enlarged cross-sectional view of the
`distal end portion of a replacement balloon catheter
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 7
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 7
`
`

`

`5,364,354
`
`5
`FIG. 7 is a cross section of the balloon catheter of
`FIG. 6 taken along the line VII—VII.
`FIG. 8 is an enlarged sectional view of the replace-
`ment balloon catheter of FIG. 6 minus its packaging
`mandrel and cover.
`
`FIG. 9 is a partial fragmentary view of an alternative
`guide wire illustrating additional features of the present
`invention.
`FIG. 10 is an enlarged cross-sectional View of the
`distal portion of an alternative dual-lumen balloon cath-
`eter illustrating additional features of the present inven-
`tion.
`
`FIG. 11 is an enlarged cross-sectional view of the
`distal portion of an alternative dual-lumen balloon cath-
`eter illustrating additional features of the present inven-
`tion.
`
`DETAILED DESCRIPTION
`
`Referring more particularly to the drawings in which
`similar elements are indicated by identical reference
`numerals, FIG. 1 shows a Y-connector generally indi-
`cated by reference 10 which is provided with an infla-
`tion port 12 and a compression hub 14 for sealing a
`catheter body to Y-connector 10. Drum 16 located at
`the proximal end of connector 10 is capable of axial
`rotation and is provided with a pin-vise 18 for securely
`holding a catheter guide wire in position. Hemostatic
`seal 20 is provided to prevent fluid leakage. Preferably,
`seal 20 is adjustable or releasable as this facilitates the
`removal or exchange of the catheter. Though not essen-
`tial to the practice of the present invention, drum 16 of
`Y-connector 10 provides a catheter implant physician
`with the ability to rotate the catheter guide wire
`clamped in pin-vise 18 in order to steer the advancing
`catheter through the desired vascular pathway without
`assistance. Additionally, as will be discussed in detail
`below, Y-connector 10 effectively seals the proximal
`end of the catheter to maintain working pressure while
`allowing rotational inputs to be directed to the guide
`we.
`
`An exemplary embodiment of the fully exchangeable,
`integrated-wire, dilation balloon catheter of the present
`invention is shown generally as reference 30 in FIG. 1
`secured to compression hub 14 of Y-connector 10 and
`comprising a flexible, small diameter guide wire 32
`extending through Y-connector 10 and along a flexible,
`elongated tubular shaft 34 having a proximal end 36 and
`a distal end 38. Flexible tubular shaft 34 is preferably
`formed of a polymeric material such as polyethylene,
`polyamide, polyimide, polypropylene, polyvinyl, poly-
`ester such as polyethyleneterephthalate (PET), or poly-
`olefm copolymer. Additionally, shaft 34 may be coated
`with PTFE, silicone or other materials including low
`friction lubricants. As shown in FIG. 1, proximal end 36
`of shaft 34 may be provided with additional protective
`sleeves 40 and 42 to strengthen the junction of shaft 34
`to Y-connector 10 and prevent kinking of the shaft
`during manipulation and placement of catheter 30.
`Distal end 38 of shaft 34 flares into an expandable
`dilation balloon 44 (shown inflated),
`the details of
`which are more readily apparent in the enlarged cross
`section of FIG. 2. As shown in FIG. 2, dilation balloon
`44 is formed as an integral part of catheter 30 in fluid
`conducting communication with an exemplary single,
`axial lumen 46 running throughout the length of tubular
`shaft 34. Though the integral construction of catheter
`30 illustrated may be preferred, alternative construc~
`tions may be utilized so long as dilation balloon 44 is
`
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`sealineg connected to distal end 38 of tubular shaft 34.
`Accordingly, dilation balloon 44 may be constructed of
`the same or different polymeric materials utilized in the
`construction of shaft 34. Similarly, low friction coatings
`such as PVC, polyamide or fluoropolymer or such as
`PTFE or hydrophilic materials and lubricants may be
`utilized to enhance the movement of all components of
`catheter 30 during angioplasty.
`Balloon 44 is provided with a distal orifice 48 which
`is coaxially aligned with lumen 46 and adapted to re-
`ceive and conduct guide wire 32 which extends
`throughout the length of balloon 44 and beyond distal
`orifice 48. Orifice 48 is provided with means for releas-
`ably engaging guide wire 32 in a sealing relationship. In
`the exemplary embodiment of the present invention the
`means for releasably engaging in sealing relationship is
`formed of a resilient sleeve 50 which extends from distal
`orifice 48 and is dimensioned to slidingly engage an
`enlarged diameter distal end portion of guide wire 32
`formed from a cylindrical collar 52 which is sealineg
`coupled to guide wire 32. Resilient sleeve 50 may be
`formed from the same material forming the remainder
`of tubular shaft 34 or may be formed from a lubricuous
`polymeric material. Alternatively, resilient sleeve 50
`may be coated along its iimer surface with a lubricuous
`material to facilitate its engagement with cylindrical
`collar 52. Cylindrical collar 52 can be formed of a wide
`variety of materials ranging from stainless steel to poly-
`meric materials and may even be formed as an integral
`part of wire 32. However, it is preferred that collar 52
`be formed of a polymeric material such as PVC, poly—
`amide, polyimide, or fluoropolymer such as polytetra—
`fluoroethylene (PTFE) as this provides an added de—
`gree of flexibility to the enlarged cross-sectional diame-
`ter distal end portion of wire 32 formed by collar 52. An
`additional advantage of forming collar 52 from materi-
`als such as PTFE is that cylindrical collar 52 may be
`sealineg coupled to guide wire 32 yet retain the ability
`to slide axially along guide wire 32. As shown in FIG.
`2, to retain polymeric cylindrical collar 52 in position
`along guide wire 32 one or more retaining beads 54 and
`56 may be soldered or brazed to guide wire 32. Altema-
`tively, adhesives or a simple mechanical fit may be
`utilized. It should also be noted that guide wire 32 and
`specifically cylindrical collar 52, may be formed from a
`lubricious polymeric material or provided with a thin
`coating of silicone, fluoropolymer or the like to increase
`its lubricity.
`This exemplary construction produces a releasably
`engaging seal which fixes guide wire 32 in position
`relative to balloon 44 yet allows guide wire 32 to be
`rotated freely without wrapping balloon 44 about the
`shaft of guide wire 32. Additionally, as shown in the
`alternative embodiment of the present invention illus-
`trated in FIG. 4, where retaining beads 54 and 56 are
`soldered somewhat proximally to the distal location of
`cylindrical collar 52, collar 52 is provided with an
`added degree of sliding axial movement along guide
`wire 32 which allows the positioning physician to ex-
`tend or retract the end portion of guide wire 32 relative
`to balloon 44 where necessary while retaining the seal
`between collar 52 and sleeve 50.
`
`resilient sleeve 50 to be slidingly advanced or retracted
`
`It should be noted that retaining beads 54 and 56
`create an outer diameter which is larger than the inner
`diameter of cylindrical collar 52 yet smaller than the
`outer diameter of cylindrical collar 52. As shown in
`FIG. 3, this construction enables the sealing means of
`
`_
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 8
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 8
`
`

`

`
`
`7
`along the cylindrical length of collar 52 in order to
`releasably engage the sealing means of the present in-
`vention. In FIG. 3 balloon 44 has been deflated and
`retracted proximally along guide wire 32 to a position
`where resilient sleeve 50 has completely disengaged
`from cylindrical collar 52. It is important to note that as
`shown in FIGS. 2 and 3 all portions of guide wire 32
`proximal to its enlarged diameter distal end portion
`formed by cylindrical collar 52 have a cross-sectional
`diameter smaller than that of the outer diameter of
`collar 52. This construction allows the balloon catheter
`of the present invention to be completely advanced or
`retracted along the entire longitudinal extent of guide
`wire 32 for the purposes of balloon manipulation, re-
`moval or replacement.
`Thus, the balloon catheter can be replaced with a
`catheter having a balloon provided with a different
`expandable diameter if necessary to reopen a particu-
`larly difficult stenotic lesion. Similarly,
`if problems
`develop with the inflation of balloon 44 during angio-
`plasty it is possible to replace the balloon with a prop-
`erly functioning device. All the vascular physician need
`do is to retract tubular shaft 34 and balloon 44 along
`guide wire 32 leaving guide wire 32 in position across
`the target lesion. Then, a replacement balloon can be
`advanced along the positioned guide wire without hav-
`ing to retrace the entire vascular pathway. As those
`skilled in art will appreciate, this greatly facilitates the
`speed and safety of such a procedure. In order to reen—
`gage the balloon on collar 52 the vascular physician
`simply advances the catheter along guide wire 32 to
`slide resilient sleeve 50 over cylindrical collar 52. Gen-
`erally, in practice, when advancement of resilient sleeve
`50 relative to collar 52 ceases a sealing engagement has
`been accomplished. The complete engagement shown
`in FIG. 2 is for purposes of illustration only. Further
`details of the balloon exchange or replacement proce-
`dure in accordance with the teachings present invention
`will be discussed with respect to FIGS. 6—8.
`To facilitate the functioning of the releasably sealing
`means of the present invention it is preferred that collar
`52 have a generally uniform circular cross section to
`define a smooth cylindrical outer surface. However, as
`shown in FIG. 5, it is contemplated as being within the
`scope of the present invention to provide collar 52 with
`a slightly tapering proximal end to ease the initial en-
`gagement of resilient sleeve 50 over collar 52 as balloon
`44 is advanced along guide wire 32. Additionally, to
`provide a more secured sealing engagement collar 52
`can be configured to include circumferential groove 60.
`Alternatively, the proximal end of collar 52 adjacent to
`retaining beads 54 and 56 may be provided with a hemi-
`spherical cross section for the same purposes as is
`shown in the alternative embodiment of FIG. 4. Simi-
`larly, beads 54 and 56 can be configured for this pur-
`ose.
`p It also should be emphasized that axial lumen 46 of
`the present invention is configured to perform a dual
`role. As shown in FIG. 2, a diameter of axial lumen 46
`is greater than that of guide wire 32. By virtue of this
`construction, axial lumen 46 is adapted to both receive
`guide wire 32 and to conduct an inflation fluid to and
`from balloon 44. This dual function design produces an
`ultra-low profile device which significantly enhances its
`ability to cross very tight stenoses or to traverse partic—
`ularly difficult vascular pathways. As an additional
`benefit,
`larger volumes of radiographic Visualization
`dyes may be injected about tubular shaft 34 to enhance
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`its visibility during placement of the apparatus relative
`to the larger diameter balloon catheters of the prior art.
`Along these lines, exemplary non-limiting dimensions
`for the balloon catheter assembly of the present inven-
`tion may be as follows. For example, as is typical in the
`coronary arts, the overall length of catheter 30 will
`typically range from 120 cm to 160 cm. The axial length
`of dilation balloon 44 will comprise approximately 1 cm
`to 4 cm of this overall length. Typically, dilation bal-
`loons are available in stepped dilation diameters ranging
`from approximately 1.0 mm to 5.0 mm in 0.5 mm or 0.25
`mm increments. As known in the art, these inflation
`diameters are typically characterized at 6 to 10 atmo—
`spheres of pressure. Naturally, the deflated profile of
`the dilation balloons increases slightly with the final
`dilation diameter. However, while the majority of prior
`art balloon catheters have a deflated balloon profile
`measuring approximately 0.04 inches in diameter, the
`balloon catheter of the present invention has a typical
`dilated balloon profile of only 0.03 inches. Similarly, the
`dual function, single lumen design of the present inven-
`tion produces a tubular shaft having a correspondingly
`narrow profile.
`Exemplary non-limiting diameters for the proximal
`portion of guide wire 32 range from 0.005 to 0.016
`inches whereas the preferred exemplary outer diameter
`of cylindrical collar 52 ranges from approximately 0.012
`to 0.018 inches. Thus, in the embodiments of the present
`invention illustrated in FIGS. 2—5 the distal end portion
`of guide wire 32 is provided with a cross-sectional di—
`ameter on the order of approximately 0.005 inches and
`cylindrical collar 52 is formed of a polymeric material
`such as PTFE having an outer diameter of approxi-
`mately 0.016 inches and a wall thickness of approxi-
`mately 0.005 inches. It should be emphasized that the
`proximal diameter of guide wire 32 need not be constant
`and may taper to provide an enhanced degree of flexi-
`bility toward the distal end of guide wire 32. Guide wire
`32 itself is preferably formed of metal such as stainless
`steel but also may be constructed of polymers or poly-
`mer coated metals as is known in the art. An exemplary
`overall wire length for guide wire 32 is on the order of
`175 cm. The cross section of guide wire 32 proximal to
`cylindrical collar 52 need not be circular to be within
`the scope of the present invention. For example, gener-
`ally elliptical or ribbon-like configurations may be uti—
`lized to provide an enhanced degree of flexibility.
`Also visible in FIG. 2 is radiopaque marker 62 formed
`of a coil of dense metal such as gold or platinum fixed at
`a position adjacent to the distal end portion of wire 32.
`Marker 62 can be secured to guide wire 32 in any man-
`ner known in the art including soldering, brazing, adhe-
`sives, or simple mechanical deformation. Radiopaque
`marker 62 functions to provide the implanting physician
`with a readily apparent visual reference which be
`viewed on a fluoroscope during the angioplasty proce-
`dure. During positioning of the apparatus the surgeon
`simply manipulates the catheter guide wire assembly of
`the present invention until marker 62 is positioned di-
`rectly adjacent or across the target lesion. Because of its
`positioning on guide wire 32 relative to dilation balloon
`44, when marker 62 is so positioned dilation balloon 44
`is positioned across the lesion as well.
`Though not essential to the practice of the present
`invention, guide wire 32 is preferably provided with a
`flexible spring coil 64 positioned distally to enlarged
`diameter cylindrical collar 52. As shown in FIGS. 2—5,
`
`spring coil 64 is preferably provided with a smooth
`
`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 9
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`Petitioner Edwards Lifesciences Corporation - Exhibit 1030 - Page 9
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`5,364,354
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`in disposable balloon cover 72. Preferably, mandrel 70
`is constructed of metal or plastic and approximates the
`outer diameter of collar 52. Additionally, mandrel 70
`may be coated with lubricating materials such as PTFE
`or silicone. The cross section of FIG. 7 illustrates an
`
`9
`hemispherical tip 66 in order to reduce vascular trauma
`as