BSC USP 8,142,413
`Exhibit 1008
`
`Page 1 of 16
`
`1111111111111 011111111111111.11119111,1111111 11)1111111111111111111 0111111
`
`(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2003/0195546 Al
`Oct. 16, 2003
`(43) Pub. Date:
`Solar et al.
`
`(54) ENHANCED CATHETER WITH ALIGNMENT
`MEANS
`
`part of application No. 09/312,529, filed on May 14,
`1999, now Pat. No. 6,394,995.
`
`(76) Inventors. Ronald J. Solar, San Diego, CA (US);
`Glen L. Lieber, Poway, CA (US)
`Correspontic lice Address.
`REED SMITH, LLP
`ATTN: PM ENT RECORDS DEPARTMENT
`599 LEXINGTON AVENUE, 29TH FLOOR
`NEW YORK, NY 10022-7650 (US)
`
`(21) Appl. No.:
`(22) Filed:
`
`10/428,668
`
`May 2, 2003
`
`Related U.S. Application Data
`
`
`Continuation of application No. 09/629,768, filed on
`(63)
`Jul. 31, 2000, which is a continuation-in-part of
`application No 09/454,255, filed on Dec. 2, 1999,
`now Pat. No. 6,447,501, which is a continuation-in-
`
`(60) Provisional application No. 60/085,636, filed on May
`15, 1998.
`
`Publication Classification
`
`Int. Cl.' ............................................ A61M 29/00
`(51)
`(52) U.S. Cl. ................. 606/192; 604/103.04; 604/528
`(57)
`ABSTRACT
`A balloon dilatation system is comprised of an elongated
`flexible advancement member which terminates in a tubular
`tracking member slidable over a guidewire. An inflatable
`balloon has proximal and distal ends, the proximal end
`communicating with an inflation channel, and the distal end
`attaching to the tracking member The balloon portion is
`coextensive with but nut attactiLd to dic advancement mem-
`ber. An align ment member aligns the advancement member
`and the inflation channel. Other embodiments relate to
`delivery of stents or other medical instrumentalities.
`
`5
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`1
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`ENHANCED CATHETER WITH ALIGNMENT
`MEANS
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`[0001] This application is a continuation of co-pending
`U.S. patent application Ser. No. 09/629,768, filed Jul. 31,
`2000, which in turn is a continuation-in-part of U.S. patent
`application Ser No. 09/454,255, filed, Dec. 2, 1999, now
`U.S. Pat. No. 6,447,501, which is a continuation-in-part of
`U.S. patent application Serial No. 09;312,529, filed May 14,
`1999, now U.S. Pat. No. 6,394,995, which is based upon
`U.S. Provisional Patent Application Serial No. 60/085,636,
`filed May 15, 1998.
`
`SCOPE OF THE INVENTION
`
`[0002] This invention relates to the fields of angioplasty
`and other interventional procedures. More particularly, this
`invent ion relates to improved balloon dilatation systems
`where the distal end of the inflatable dilatation balloon is
`an ached to a tubular tracking member or an acLvancement
`member and alignment means align the tracking member
`and an inflation channel.
`
`BACKGROUND OF THE INVENTION
`
`[0003] Balloon dilatation catheters have been used to
`dilate various types of strictures in blood vessels and other
`body lumens for over twenty years. Typically, such catheters
`comprise a balloon mounted on the distal end of an elon-
`gated flexible shaft and an inflation tube or lumen extending
`longitudinally within the shaft from its proximal end to the
`interior of the balloon. Among the major advancements in
`balloon dilatation catheters have been the development of
`smaller catheters that can be used in smaller and/or more
`distal anatomical locations, and the development of cath-
`eters that can be rapidly exchanged. Examples of such
`catheters are described in U.S. Pat. No. 4,748,982 (Horze-
`wski), Pat. No. 4,762,129 (Bonzel), Pat. No. 5,040,548
`(Yock), Pat. No. 5,061,273 (Yock), Pat. No. 5,569,199
`(Solar) and Pat. No. 5,728,067 (Luger). Because these
`catheters have become more sophisticated and complex in
`design, and despite the nnanufa,:.turers's experience in manu-
`facturing them, these catheters are expensive to make.
`Furthermore, despite these improvements, difficulties are
`still encountered in advancing catheters through tortuous
`anatomy and safely crossing very tight strictures and
`stenoses in the vascular system and other body lumens or
`cavities.
`[0004] Recently vascular stents have been shown to play
`an important role in reducing the restennsis rates associated
`with balloon angioplasty. However, stents are sometimes
`lost from the delivery systems and are difficult to retrieve
`safely. In addition, stents cannot completely overcome the
`trauma and injury that result from balloon dilatation. Thus,
`there is a need for enhanced balloon dilatation catheters.
`
`OBJECTS OF THE INVENTION
`
`[0005] It is an object of the invention to provide an
`enhanced dilatation system that is extremely low-profile to
`more easily and safely cross very tight strictures and
`stenoses in the vascular system and other body lumens or
`cavities.
`
`[0006] It is also an object of the invention to provide an
`enhanced dilatation system that provides for an improved
`means for crossing tight stenoses, as well as to navigate
`tortuous anatomy.
`
`[0007] It is another object of the invention to provide an
`enhanced dilatation system that has the ability to be
`exchanged rapidly.
`
`[0008] It is yet another object of the invention to provide
`an enhanced dilatation system that can be used to retrieve
`dislodged stents.
`
`[0009] It is a further object of the invention to provide an
`enhanced dilatation system that can he manufactured inex-
`pensively and mere reliably then currently available balloon
`dilatation systems.
`[0010] It is also an object of the invention to provide an
`enhanced dilatation system that allows placement of an
`additional catheter or instrumentality adjacent to a catheter.
`
`[0011] It is likewise an object of the invention to provide
`an enhanced dilatatinn system that facilitates placement of
`stents or stent grafts.
`
`[0012] It is a yet further object of the invention to provide
`a balloon catheter system and a stent delivery system having
`a smaller profile for crossing tight stenoses.
`[0013] These and other objects of the invention will
`become more apparent from the discussion below.
`
`SUMMARY OF THE INVENTION
`
`[0014] According to the invention, an enhanced balloon
`dilatation delivery system comprises an elongated advance-
`ment member which optionally terminates in a tubular
`tracking member, an inflatable dilatation balloon having
`proximal and distal ends and being in fluid communication
`with an inflation channel, and means for aligning the
`advancement member and the inflation channel. The proxi-
`mal end of the inflatable balloon is in fluid communication
`with the inflation channel, and the distal end of the inflatable
`balloon is attached to the tubular tracking member or the
`advancement member. During advancement of the system,
`the inflatable dilatation balloon and inflation channel are
`somewhat coextensive with the advancement member. The
`system is slidable over a guidewire.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`[0015] The above and other objects and advantages of the
`invention will be apparent upon consideration of the fol-
`lowing detailed description, taken in conjunction with the
`accompanying drawings, in which the reference characters
`refer to like parts throughout and in which:
`[0016] FIGS. 1 to 3 are each a schematic, lateral view of
`an embodiment of the invention;
`[0017] FIG. 4 is an enlarged illustration of the distal
`portion of an additional embodiment of the invention;
`[00B] FIG. 5 is an enlarged illustration of the proximal
`portion of an alternate embodiment of the invention;
`[0019] FIG. 6 is a cross-sectional view of a clamping
`member used in the FIG. 5 embodiment;
`
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`[0020] FIGS. 7 and 8 are each a schematic, lateral view
`of an additional embodiment of the invention;
`[0021] FIG. 9 is a schematic, partly cross-sectional view
`of another embodiment of the invention and FIG. 10 is a
`cross-sectional view across line 10-10;
`[0022] FIG. 11 is an alternate gauss-sectional view of
`FIG. 10;
`[0023] FIGS. 12, 13 and 14 are each a schematic repre-
`sentation of another embodiment of the invention; and
`[0024] FIG. 15 is a detail of FIG. 14.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`[0025] With reference to FIGS. 1 to 3, an enhanced
`catheter system, designated generally as 1, has an elongated
`advancement member 5. Preferably advancement member 5
`is formed of a flexible wire or, alternately, of spring hollow
`hypotubing. Advancement member 5 preferably has a diam-
`eter of from about 008" to 0 015", which diameter could be
`larger or smaller depending On the application. Advance-
`ment member 5 has sufficient column strength and flexibility
`to provide for advancement of the catheter through tortuous
`anatomy. Preferably, advancement member 5 is rigid at its
`proximal end and becomes increasingly more flexible as it
`extends distally. This may be accomplished by a number of
`ways known in the art, including, but not limited to, taper-
`ing, selective heat treatment and/or forming advancement
`member 5 from a composite of materials with various
`properties.
`[0026] Advancement member 5 terminates at its distal end
`6 in an elongated tubular tracking member 7. Tracking
`member 7 has a tubular configuration and is adapted to slide
`over a standard guidewire 9 to allow system 1 to advance
`easily to a desired location within a patient's body. Tracking
`member 7 has an open proximal end 11 and an open distal
`end 8, and is preferably funned of a flexible polymeric tube,
`a spring coil, or a combination thereof. Tracking member 7
`is preferably about 10 to 50 cm long and has an inner
`diameter that is sized to accommodate guidewire 9, most
`preferably approximately from about 0.012" to 0.040".
`Optionally tracking member 7 has an inner, outer, or inner
`and outer coating with a lubricious material to aid in its
`movement over the guidewire. Lubricious materials for this
`purpose are well-known in the art.
`[0027] Advancement member 5 and tracking member 7
`are attached by any suitable means known in the art, such as
`by fusion or a non-toxic adhesive. Alternatively, advance-
`ment member 5 and tracking member 7 may be integrally
`formed during manufacture.
`[0028] System 1 also has an inflatable balloon 10 having
`a proximal end 12 and distal end 14. Distal end 14 of balloon
`10 is attached to tracking member 7 by any suitable means
`known in the art, such as by fusion, adhesive bonding or
`integral formation, and moves therewith. Distal end 14 of
`balloon 10 may be attached to distal end 8 of tracking
`member 7, as shown in FIG. 1, or preferably, distal end 14
`of balloon 10 is attached to the proximal end 11 of tracking
`member 7, as shown in FIG. 3. Balloon 10 is formed of a
`very thin-walled, preferably less than 0.001" thick, poly-
`meric material. Balloon 10 may be formed of any one of a
`
`variety of suitable materials known in the art. Optionally
`balloon 10 may he suitable for dilatation and/or deployment
`of a stent.
`[0029] Proximal end 12 of balloon 10 communicates with
`an elongated inflation channel 15 that extends proximally
`through a corporeal lumen. Inflation means 15 is formed
`preferably of a polymeric tubular film that will allow infla-
`tion channel 15 to collapse to a smaller profile when not
`being used for inflation of balloon 10. The wall thickness of
`inflation channel 15 should preferably be less than 0.001".
`When inflated, inflation channel 15 will have a diameter of
`approximately 0.010" or more, depending upon the appli-
`cation. Alternatively, inflation channel 15 may be fabricated
`out of a non-collapsible tubing material as would be familiar
`to one skilled in this art. As shown in FIG. 3, inflation
`channel 15 may have position markers 13 on its proximal
`portion. Position markers 13, which may be applied by ink
`or other suitable means known in the art, cm-respond to
`similar markers on advancement member 5. Such markers
`provide visual confirmation of concurrent movement of
`inflation channel 15 and advancement member 5 during
`advancement and withdrawal of system 1.
`[0030] Inflation channel 15 has a hub 16 at its opposite,
`proximal end. Hub 16 is a standard LUER® lock connector
`that allows connection of inflation means 15 to standard
`balloon inflator devices or syringes (not shown). By this
`means, balloon 10 is in fluid communication with an inflator.
`[0031] As noted above, distal end 14 of inflatable balloon
`10 is attached to tubular tracking member 7. In this way, as
`tubular tracking member 7 travels through the body along
`the path of Etuidcwire 9, inflatable balloon 10 is pulled along
`with tracking member 7 to the desired site. However,
`although balloon 10 lies coextensively with advancement
`member 5 (FIGS. 2 and 3) and/or tracking member 7 (FIG.
`1), it is unattached to advancement member 5. In this most
`preferred embodiment of least attachment, pushing on
`advancement member 5 causes balloon 10 to be easily
`pulled through the anatomy and tight strictures and stenoses.
`Since the balloon is not being pushed through a stenosis,
`there is no tendency for the balloon to compress longitudi-
`nally and increase in profile and bulk. Such an occurrence,
`which may he found in prior art catheters where the balloon
`is att ached proximally and distally to the catheter shaft, can
`impede acMiriccrrieril and crossing., as well as result in
`vascular trauma and clinical complications. Since there is no
`bulky catheter structure within the interior of the balloon (as
`is found in prior art catheters), the very thin balloon material
`can easily told and conform as required to cross a stenosis
`with minimal friction and trauma as it is pulled across by the
`tracking member.
`[0032] As shown in FIG. 3 a wire 2 can optionally extend
`at least partially within the inflation channel 15 to the distal
`end 14 of balloon 10. Wire 2 may provide support to the
`inflation channel 15 and balloon 10 which may be required
`in some applications. The support wire may be permanently
`mounted, or alternatively, it may he removable and used as
`needed. Also, as shown in FIG. 3, the dilatation system may
`have radiopaque markers 17 to allow the system's position
`to be monitored, and the proximal ends of the advancement
`member 5 and/or inflation channel 15 may have one or more
`visual markers 13 to indicate the lengths inserted. The
`radiopaque markers may be comprised of conventional
`
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`3
`
`radiopaque materials such as gold or platinum, and the
`visual markers may be comprised of physiological accept-
`able inks or coatings, preferably in bright or fluorescent
`colors.
`[0033] The embodiment of the invention shown in FIG. 7
`has an inflatable balloon 22 and a flexible, torqueable,
`advancement member 23. The distal portion 24 of balloon
`22 is fixedly attached to the distal end 25 of advancement
`member 23. Advancement member distal end 25 may
`optionally have a flexible spring tip 26.
`[0034] The proximal portion 27 of balloon 22 is in fluid
`communication with an inflation channel or means 28 hav-
`ing a hub 29 for connection to an inflation source (not
`shown). Inflation channel 28 preferably is attached to or
`wound about advancement member 23 in spiral fashion, in
`such a way to lower the profile of the system but to not
`interfere with the fluid communication.
`[0035] A torquer or rotator member 30 may optionally grip
`the proximal portion of advancement member 23 and intla-
`lion channel 28, to allow radial positioning of advancement
`member 23. In this embodiment it is preferred that the
`in nal itin means spirally wrap around the advancement mem-
`ber. Turning the proximal end of the advancement member
`with torquer 30 will allow distal end 25 of the advancement
`member 23 to be positioned at a desired radial location
`relative to balloon 22 within a corporeal lumen. A torquer 30
`could also be used with the embodiments shown in FIGS. 1
`and 2, where the tracking means and advancement means
`would be radially positioned.
`[0036] In FIG. 9, an enhanced balloon dilatation system,
`designated generally as 80, has an elongated advancement
`member 82. Preferably advancement member 82 is formed
`of a flexible wire or, alternately, of spring hollow hypotub-
`ing, and has the characteristics described above.
`[0037] Advancement member 82 terminates at its distal
`end 84 in a tubular track *, member 86. Tracking member
`86 has a tubular configuration and is adapted to slide over a
`standard guidewire 88 to a] [ow system 80 to advance easily
`to a desired location within a patient's body. Tracking
`member 86 has an open proximal end 90 and an open distal
`end 92, and is preferably formed of a flexible polymeric
`tube, a spring coil, or a combination thereof. Tracking
`member 86 is preferably about 3 to 30 cm long and has an
`inner diameter that is sized to accommodate guidewire 88,
`most preferably approximately from about 0.012" to 0.040".
`Optionally tracking member 86 has an inner, outer, or inner
`and outer coating with a lubricious material to aid in its
`movement over the guidewire.
`[0038] Advancement member 82 and tracking member 86
`are attached by any suitable means known in the art, such as
`by fusion or a non-toxic adhesive, or, alternatively, have
`been integrally formed during manufacture.
`[0039] System 80 also has an inflatable balloon 94 having
`a proximal end 96 and distal end 98. Distal end 98 of balloon
`94 is attached to advancement member 82 or tracking
`member 86 by any suitable means known in the art, such as
`by fusion, adhesive bonding or integral formation, and
`moves therewith. Distal end 98 of balloon 94 may he
`attached to advancement member 82, as shown in FIG. 9, or
`optionally distal end 98 of balloon 94 can be attached to the
`proximal end 90 of tracking member 86, as similar to the
`
`arrangement shown in HG. 3. Balloon 94 is formed of a
`very thin-walled, preferably less than 0.001" thick, poly-
`meric material, of any one of a variety of suitable materials
`known in the art.
`[0040] Proximal end 96 of balloon 94 communicates with
`an elongated inflation channel 100 that extends proximally
`through a corporeal lumen. Inflation channel 100 is formed
`preferably of a polymeric tabular film that will allow infla-
`tion channel 100 to collapse to a smaller profile when not
`being used for inflation of balloon 94. When inflated,
`inflation channel 100 will have a diameter of approximately
`0.010" or more, depending on the application. Alternatively,
`inflation channel l00 may be fabricated out of a non-
`collapsible tubing material as would be familiar to one
`skilled in this art.
`[0041] Inflation channel 100 has a hub 101 at its opposite,
`proximal end. Hub 101 is a standard LLTER12 lock connector
`that allows connection of inflation channel 100 to standard
`balloon inflator devices or syringes (not shown). By this
`means, balloon 94 is in fluid communication with an inflator.
`[0042] An alignment member or sheath 102 extends lon-
`gitudinally, whereby it encompasses at least inflation chan-
`nel 100. Alignment member 102 preferably is attached to or
`integral with advancement member 82, and preferably
`advancement member 82 also is encompassed by alignment
`member 102. Alignment member 102 can be comprised of
`any suitable flexible or substantially flexible medically
`acceptable material, such as a polymer or metal. In a
`preferred embodiment alignment sheath comprises a stain-
`less steel hypotuhe and advancement member 82 is bonded
`to its inner or outer surface.
`[0043] The distal end 104 of alignment member 102 is
`open, and the proximal end 106 of alignment member 102
`is optionally attached to hub 101, optionally with an opening
`for the proximal portion 108 of advancement member 82.
`[0044] In the cross-sectional view along line 10-10 in
`FIG. 9 that is represented by FIG. 10, advancement member
`82 and inflation channel 100 are positioned within alignment
`member 102. However, in an alternative embodiment
`reflected in FIG. 11, advancement member 82 is attached to
`the outer surface 110 of alignment member 102.
`
`[0045] In a preferred embodiment the d a ....vduceniont mem-
`
`ber has a proximal portion and a distal portion. The proximal
`portion has at least one lumen having open ends. Inflation
`channel 100 is positioned within one of said lumens and the
`proximal portion of the advancement member functions as
`the alignment member. The distal portion of the advance-
`ment member extends distally from the distal end of the
`proximal portion of the advancement member.
`[0046] In a preferred embodiment of the invention a stent
`or stent graft may be delivered. An example of this preferred
`embodiment is shown in FIG. 12. In this embodiment, an
`inflatable balloon 40 is folded and formed into a tubular
`shape, and a stent or stern graft 42 is mounted onto the
`balloon by various methods known in the art such as, for
`example, crimping, interlerence fit, or encapsulal ion. See,
`for example, U.S. Pat. Nos. 4,800,882 and 5,836,965. In this
`embodiment, the distal end 44 of balloon 40 is attached to
`advancement means 46 adjacent to the distal end of
`advancement means 46, and the balloon/stent assembly
`
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`40/42 ads as a tracking member. The proximal end 48 of
`balloon 40 is in fluid communication with hub 50 through
`flexible conduit 52.
`
`[0047] Alternatively, the embodiment illustrated in FIG. 1
`may be used to deliver a stent or stent graft. With the distal
`end 14 of balloon 10 attached to the distal end S of the
`tracking member 7, the balloon is folded around tracking
`member 7, and the stent/stent graft 54 is mounted onto the
`folded balloon (FIGS. 1 and 13). Tracking member 7 is
`advanced over guidewire 9.
`
`[0048] In the embodiment shown in FIGS. 14 and 15, the
`distal end 62 of an inflatable balloon 64 is attached to the
`proximal end 66 of a tracking member 68. Balloon 64 is
`folded and formed into a tubular shape, and a gent or stent
`graft 70 is mounted onto the balloon by various methods
`known in the a rt. Optionally, a sheath can be extended over
`the stem (various designs and methods are known in the art).
`
`[0049] To summarize use of the embodiments of the
`present invention described above, a guidewire is first laid in
`place within a corporeal lumen through any of the means
`well-known in the art. With use of an advancement member,
`a tracking member or folded balloon is advanced into the
`corporeal lumen over the guidewire. As the advancement
`member or folded balloon is advanced into the corporeal
`lumen, an inflatable balloon is pulled along with it by virtue
`of the attachment of its distal end to the tracking member or
`the advancement member. Once the inflatable balloon is in
`a desired position within the corporeal lumen, the balloon is
`inflated via the inflation means and hub.
`
`[0050] It is contemplated that the tracking member can be
`varied to provide alternative embodiments of the catheter
`system of the invention. For example, the length of the
`tracking member may either he made longer or shorter. In
`the embodiment of the invention shown in FIG. 2, the
`tracking means has been shortened to a loop 18. Alterna-
`tively, it is contemplated that the tracking member may
`extend as an elongated tubular member the full length of
`system, from a proximal position outside the body lumen all
`the way to its distal end, to allow fluid administration of the
`treatment site. Also, the distal end of the advancement
`member could extend distally of the tracking member.
`Moreover, in one embodiment of the invention the inflatable
`balloon may be detachable.
`
`[0051] In addition, it is contemplated that the tracking
`member may be single-lumen, so that it accom modates only
`a guidewire, or it may be multi-lumen, so that i t ca n perform
`other functions as well. For example, the multi-lumen track-
`ing member 19 shown in FIG. 4 contains lumen 3 for
`advancing over guidewire 9 and lumen 211, which provides
`a convenient means for attachment to advancement member
`5. Advancement member 5 may be hollow to provide an
`alternative means for fluid administration to the treatment
`site. Lumen 20 may be open at the distal end 4 of tracking
`member 19, and tracking member 19 may alternatively have
`side holes 21 which provide communication from lumen 20
`to the exterior of tracking member 19. Tracking member 19
`may also be enlarged and/or lengthened to facilitate perfu-
`sion during balloon inflation.
`
`[0052] It is further contemplated that, in some applica-
`tions, it may he deemed desirable to provide one or more
`additional attachment points between the inflation channel
`
`and the advancement member at various locations along the
`advancement member's length. A preferred method of
`attachment employs a removable clamping member 22 as
`shown in FIGS. 5 and 6. Clamping member 22 holds
`inflation channel 15 stationary with respect to advancement
`member 5 clurim7 with:tr.o.val of catheter system 1. Clamping
`member 22 is preferably removed or loosened during cath-
`eter system advancement to optimize the pulling forces on
`the balloon. it is contemplated that in some instances more
`than one clamp 22 might be used.
`[0053] Further, it is envisioned that the inflatable balloon
`and the inflation channel may be formed from the same
`material or they may he formed independently and subse-
`quently attached by suitable known means. In addition, the
`distal extension of the balloon may he molded or otherwise
`formed to the shape of the tracking member.
`[0054] In yet another alternative preferred embodiment of
`the invention, the advancement member and the tracking
`member may be formed in multiple segments each having
`varying mechanical properties which will allow for the
`customization of the catheter to a particular need.
`[0055] The catheter systems of the present invention pro-
`vides the user with a number of significant advantages not
`otherwise obtainable with currently available catheters. For
`example, they are less bulky than other available catheter
`systems and thus the balloon is able to move against
`resistance more easily, which allows less traumatic crossing
`of restrictions. Also, pushing on the advancement member
`has the effect of pulling the balloon along through the
`stenosis, a nil avoids the problem of bunching or gathering
`which occurs with other catheters. With a thin film balloon
`and inflation channel there is no dead space or volume that
`needs to he evacuated prior to use therefore, little or no
`preparation is required. The smaller profile of the catheter
`system of the invention allows the inflatable balloon to be
`passed through stents easily Partial inflation of the inflatable
`balloon can grab a previously inserted stent and facilitate
`retrieval of the stent. The smaller profile also permits
`passage through displaced stern struts.
`
`[0056] Separating the inflatable balloon from a catheter
`shaft allows greater design flexibility to allow one to provide
`catheter systems with improved handling characteristics,
`and the fewer bonds between the balloon and the advance-
`ment shaft results in greater reliability. The simplicity of
`construction of the system of the present invention results in
`lower manufacturing costs. For example, fewer bonding
`operations are required, and expensive balloon folding pro-
`cesses can he avoided. Inflating the balloon against the
`advancement member or tracking member provides a
`focused force to enable the user to crack hard lesions at low
`pressure before the balloon is fully inflated. Doing so would
`allow vessel stretching to occur at a lower strain rate, which
`would minimize the trauma associated with balloon dilata-
`tion. With At guide sire in place, the balloon can be inflated
`additionally apt list the. gnidewire, thus providing an addi-
`tional area of focused force.
`
`[0057] A further advantage of the present invention is that
`the design allows additional catheters or devices to be placed
`over the guidewire adjacent to the inflatable balloon, and to
`be exchanged without first removing the catheter system. In
`addition, the advancement member may also act as an
`additional guidewire. For example, while balloon catheter 1
`
`

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`Page 14 of 16
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`US 2003/0195546 Al
`
`Oct. 16, 2003
`
`5
`
`is in place within a vascular lesion, a second dilatation
`system or catheter may he advanced over the advancement
`member and its balloon positioned along side the first
`balloon (to increase the effective diameter of the dilatation)
`or adjacent to the first balloon (to increase the ell ective
`length of the dilatation). An imaging catheter such as an
`intravascular ultrasound catheter may be placed next to the
`first balloon to access the progress of the treatment without
`removing the balloon. A drug delivery catheter may be
`utilized in this manner, and the balloon of system 1 may be
`inflated at low pressure to provide vascular occlusion to
`improve the efficacy of the drug delivery. Likewise, various
`other catheters and devices may be suitably employed.
`[0058] Although the discussion above has been concerned
`with inflatable balloon systems and/or catheters, other types
`of catheters or systems may embody the present invention as
`schematically illustrated in FIG. 8. In FIG. 8, advancement
`member 5 term i n a tes in a tubular tracking member 7, which
`tracks over guidewire 9. Distal end 32 of instrumentality 31
`is attached to tracking member 7. Proximal end 33 of
`instrumentality 31 is unattached to either advancement
`member 5 or tracki rig member 7. Instrumentality 31 may be
`a laser, infusion tube, suction device, atherectomy means,
`other stent expansion means or another therapeutic or diag-
`nostic apparatus. As required, a connecting member 34 may
`be attached to instrumentality 31. Connecting member 34
`may be an electrical conducting wire, optical ilber, tube, or
`the like_
`[0059] It will thus be seen that the objects set forth above,
`among those made apparent from the preceding description,
`are efficiently attained, and since certain changes may he
`made in the constructions set forth without departing from
`the spirit and scope of the invention, it is intended that all
`matter contained in the above description and shown in the
`accompanying drawings shall be interpreted as illustrative
`and not in a limiting sense.
`[0060] It is also to be understood that the following claims
`are intended to cover all of the generic and specific features
`of the invention herein described and all statements of the
`scope of the invention, which, as a matter of language, might
`be said to fall therebetween.
`
`What is claimed is:
`1. A balloon dilatation catheter system comprising:
`a flexible elongated advancement member having a distal
`end,
`a tracking member having a proximal end and a distal end,
`said tracking member being adapted to slide over a
`guidewire and being fixedly attached to the distal end
`of the advancement member,
`an inflation channel, and
`an inflatable dilatation balloon having proximal end and
`distal end, the proximal end of the balloon being in
`fluid communication with the inflation channel,
`wherein the distal end of the balloon is attached to the
`tracking member and an alignment member aligns the
`advancement member and the inflation channel in the
`longitudinal direction.
`2. The catheter system of claim 1, wherein the tracking
`member comprises two or more lumens.
`
`3. The catheter system of claim 1, wherein the dilatation
`balloon is attached to the distal end of the tracking member.
`4. The catheter system of claim 1, wherein the dilatation
`balloon is attached to the proximal end of the tracking
`member.
`5. The catheter system of claim 1, wherein the tracking