.
`United States Patent
`
`[19]
`
`U8005102403A
`[11] Patent Number:
`
`5,102,403
`
`A r. 7, 1992
`[45] Date of Patent:
`Alt
`W__________E____
`
`[54] THERAPEUTIC MEDICAL INSTRUMENT
`FOR INSERTION INTO BODY
`Inventor:
`Eckhard Alt, Eichendorffstrasse 52
`8012 Ottobrunn, Fed. Rep. of
`Germany
`
`[76]
`
`’
`
`[2]] Appl. No.: 539’153
`[22] Filed:
`Jun. 18, 1990
`
`‘
`
`Egg
`
`5
`{312C161 GM/ggéMégf/gf):
`'
`'
`' """""""""""""""""""""
`,128/775
`[58] Field of Search .................................. 604/96—101
`604/280 264‘ 606/191 194 195. 128/207.15
`’
`’
`’
`’673, ’675, 692, 772’
`
`[56]
`
`References Cited
`V
`U.S. PATENT DOCUMENTS
`4,850.358
`7/1985 Millar .................................. 128/675
`4,983,167
`1/1991 Sahota ................................... 604/96
`
`Primacv Examiner—C. Fred Rosenbaum
`Assistant Examiner—William Lewis
`
`Attorney, Agent, or Firm—Laurence R. Brown
`
`[57]
`
`ABSTRACT
`
`This invention provides a cylindrical plastic catheter of
`the type having a distal end portion movable over a
`guide wire to a treatment site such as a stenosis in the
`
`cardiovascular system, wherein the catheter shape
`gradually changes from a tubular configuration with a
`cylindrical skin defining an interior inflating lumen. The
`skin configuration and internal lumen changes shape
`gradually along the catheter length for insertion of the
`wire into a resident guide lumen resident only in the
`distal end portion without bends or kinks in the wire
`and retaining a generally parallel disposition to the
`catheter axis from which it departs to penetrate the
`catheter. Thus a guiding groove in the skin gradually
`transforms into a crescent partly surrounding the guide
`Wire before Changing into a “”0”?“ WW defining a
`, guide wire lumen. The diameter of the Catheter is thus
`kept constant and small with consistent axial stiffness
`throughout its length for supporting withdrawal and
`intrusion from external axial forces. The balloon mounts
`on the catheter body cylinder for a better, more secure
`seal and the “ial forces along the catheter are balanced
`3130‘“ the “is 50 that there is no tendency to bUCkle 0r
`veer with entry or withdrawal forces. By supplying a
`groove along the length of the catheter body to receive
`nested therein a parallel guide wire, the outer circum-
`ferencial dimension of the combination guide wire-
`catheter body may be reduced for entry into vessels of
`restricted size.
`
`24 Claims, 1 Drawing Sheet
`
`
`
`BSC USP 8,142,413
`Exhlblt 1020
`Page 1 of 7
`
`BSC USP 8,142,413
`Exhibit 1020
`
`Page 1 of 7
`
`

`

`US. Patent
`
`Apr. 7, 1992
`
`5,102,403
`
`
`
`F/G.2
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`2/
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`40
`
`2/
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`7
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`2/
`
`2/
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`42
`
`26
`
`.
`
`42
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`42
`
`F/G.3
`
`FIG-4
`
`‘
`
`F/G.5
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`F/G.6
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`‘\ \6 1%)
`
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`
`42
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`FIG. 7
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`FIG. 8
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`FIG. 9
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`FIG. /0
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`PageZof?
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`

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`1
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`5,102,403
`
`THERAPEUTIC MEDICAL INSTRUMENT FOR
`INSERTION INTO BODY
`
`TECHNICAL FIELD
`This invention relates to instruments and methods of
`
`therapeutic treatment of the body at internal body sites
`and more particularly it relates to dilatation catheters
`movable along coronary blood vessels upon a guide
`wire to position an uninflated balloon at a site for treat-
`ing stenosis by subsequent inflation of the balloon, or
`the like.
`
`BACKGOUND ART
`
`The art balloon dilatation catheters for treatment of
`stenosis in coronary blood vessels is well developed.
`Representative U.S. patented art includes the following
`briefly discussed catheters:
`G. T. Schejeldahl, et a1., U.S. Pat. No. 4,413,989 Nov.
`8, 1983 was concerned with long treatment periods in a
`balloon catheter inserted over a guide wire and thus
`provides for dilation without interruption of the blood
`supply with a lumen for bypassing blood.
`A. Kuhl, U.S. Pat. No. 4,439,186 provides for pulsat-
`ing pressure for expansion and contraction of the bal-
`loon to permit blood flow past the balloon.
`J. J. Leary, U.S. Pat. No. 4,545,390 is concerned with
`steering the balloon and thus provides a steerable end to
`the guide wire upon which the balloon rides.
`M. J. Horzewski, et al., U.S. Pat. No. 4,748,982 June
`7, 1988 provides a balloon dilatation catheter with a
`short distal end portion moving along a guide wire with
`the feature of decreasing stiffness of the catheter body
`from the proximal extremity to the distal extremity in
`order to overcome difficulties in pushing prior catheters
`to a treatment site.
`T. Bonzel, U.S. Pat. No. 4,762,129, Aug. 9, 1988
`provides a stiffener wire in a separate balloon dilating
`lumen positioned parallel to the guide wire except at the
`distal end to aid in pushing the balloon to the treatment
`site.
`There still reamin many unsolved problems in the art
`of treatment of a site within the body with instrumenta-
`tion located in part outside the body. In the dilatation
`catheter art, for example, there are problems of pushing
`catheters into position at the treatmenmt site through
`restricted body vessels. Any unbalance of thrust forces
`or bends or kinks in te catheter can interfere with inser-
`tion or withdrawal. Critical is the friction encountered
`in moving a catheter along a guide wire. While consid-
`erable friction is removed by inserting the guide wire
`only at a distal end region of the catheter, the adds
`criticality by introducing a tendency to tilt or veer in
`the presence of slightly off axis thrust forces or unbal-
`ances of size, strength or axial stiffness of the catheter
`body. This is particularly evident at entrance point of
`the wire into the catheter body, where it is common to
`bend or distort the path of the guide wire, thereby add-
`ing unwanted friction and guiding problems. An exam-
`ple of this is given by the sharp bending zone in the
`guidewire set forth in the Horzewski patent.
`Furthermore with dilatation balloon structure affixed
`to the catheter body and subjected to dilating by means
`of injecting fluid at high pressure, there are sealing and
`inflation problems. Thus, because of the high inflation
`pressures, any attempt to seal on a non-cylindrical sur-
`face produces a tendency to either produce leakage by
`tearing away the sealing joint or an uneven inflation of
`
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`the balloon structure causing weak points or misshap-
`ing. Shaping is critical for passage into stenosis areas,
`and leakage or pressure limitations critical to the treat-
`ment and safety of the patient.
`Another problems area is the abrupt transition of a
`catheter tubing body or lumen at transition areas for
`entry of a guide wire or mounting of a balloon. This can
`for example tend to cause damage to vesel sidewalls or
`as heretofore discussed by causing the short distal end
`rider type of catheter geneally preferable to reduce
`friction on insertion between the catheter and the guide
`wire or its connection tubing to bend, veer, buckle or
`bind on the guide wire in response to pushing or pulling
`axial forces exerted along the catheter axis to insert or
`withdraw the catheter.
`
`The distal end profile of a balloon is critical particu-
`larly if it needs to be forced through a stenosis. The
`flexibility of the balloon for dilation is inconsistent with
`the initial need for penetration of restricted passage-
`ways to position the balloon at a treatment site for dila-
`tion. As a matter of fact any abrupt transition from one
`material to another or from one shape to another as it
`occurs if two separate lumens—one for inflation of the
`balloon and one for guidance of the wire—cause an
`abrupt joint between the lumens such as in the catheter
`suggested by Bonzel, supra, such abrupt changes pro-
`vide problems of insertion, positioning and reliability.
`Particularly for coronary blood vessel
`treatment,
`small diameters, known as low profile, for insertion into
`branch vessels and flexibility to bend around sharp cor-
`ners is critical. Thus balloons attached to stiff tubings or
`those unadapted to bend around a vessel curve are of
`limited use as well as those requiring significant room
`resulting in greater diameters of the catheter body for
`mounting elements affixing the balloon structure .upon
`the catheter.
`
`Very critical to coronary vessel treatment is the quick
`interchange of dilatators of different size. Thus a
`smaller diameter dilatator balloon may be used for pene-
`tration of the stenosis and enlargement enough to ac-
`commodate a larger diameter balloon necessary to re-
`store a reasonably normal working diameter in the ves-
`sel.
`
`It is therefore a particular object of this invention to
`provide an improved dilatation catheter particularly
`adapted for angioplasty and treatment of coronary ves-
`sels that resolves the foregoing problems in the prior
`art.
`
`A more general object is to provide improved instru-
`mentation and treatment methods for therapeutic treat-
`ment at sites within the body from the outside.
`Other objects, features and advantages of the inven-
`tion will be found throughout the following description,
`and in the accompanying drawings and claims.
`DISCLOSURE OF THE INVENTION
`
`This invention provides therapeutic instrumentation
`and treatment methods for treatment inside the body of
`the type that is passed over a guide wire of positioning
`at the treatment site. A specific example is an inflatable
`dilatation catheter specially adapted for arteriosclerotic
`vessel treatment of stenosis or angioplasty. The catheter
`is of the type riding on a guide wire only at a short distal
`end portion. Novel features of this catheter include the
`transition of the catheter tubing, typically plastic having
`a cylindrical thin skin-like wall surrounding a single
`inflation lumen for dilating and accompanying balloon
`
`Page3of7
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`Page 3 of 7
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`

`

`3
`to accommodate a second guide wire lumen at a prede-
`termined length of the catheter body near the distal end.
`Thus the configuration of a conventional cylindrical
`catheter tubing with outer plastic wall defining a single
`internal lumen changes gradually while passing through
`successive configurations at the more distal (balloon)
`end. Thus the generally substantially cylindrical outer
`wall, becomes grooved to guide a substantially parallel
`guide wire alongside toward the interior of the catheter
`without any substantial bending of the wire. The cathe-
`ter groove then progressively leads into a crescent
`shaped wall-lumina configuration which partially en-
`compasses the guide wire before becoming cylindrical
`to surround the guide wire as a toroid. In parallel to this
`grooving and encompassing process, the inner lumen of
`the catheter changes its shape as well from round
`towards more of a C-shaped configuration. This unique
`and novel feature contributes significantly to smaller
`total diameter of dilatation catheters despite the same
`mechanical strength for pushing the catheter forward,
`compared to conventional arrangement with two paral-
`lel cylindrical lumens. The distal end lumen and body
`structure finally tapers into a low profile solid nose
`adapted for working its way through stenosis before the
`balloon affixed to the cylindrical length of the catheter
`body is placed at the stenosis. The wall of the inflating-
`deflating tube is apertured at the site of the balloon to
`connect the balloon via the inflating-deflating lumen
`within the catheter body to the outside of the human
`body for operation of the balloon by fluid injection
`under pressure. This provides a short low friction rider
`of limited length and of small diameter substantially
`cylindrical. This cylindrical diameter extends along the
`entire length of the distal catheter body that it can be
`introduced into smaller vessels in the coronary system
`for treatment.
`
`The novel structure permits construction at the entry
`position of the guide wire into the catheter body at a
`position having a common shape and consistent still
`axial strength with the rest of the catheter body to facili-
`tate feeding into a treatment site. A lateral modulus of
`elasticity sufficient
`to permit bending about sharp
`curves is provided within the plastic catheter body
`devoid of stiffener wires. The bending is enhanced
`around curves by the novel form of the inflating lumen
`as a C-shaped lumen, which bends readily as the cathe-
`ter is inserted. It also readily permits withdrawal and
`replacement of small diameter catheters in small pas-
`sagesways with progressively increasing balloon sizes
`when needed.
`
`When a catheter and a guide wire are inserted into an
`arterial vessel of sufficient size over an introducer sheet,
`the diameter of the dilatation catheter plus that of a
`guide wire lying outside the catheter is not critical to
`the possibility to introduce the system into the human
`body. But there are conditions where severely diseased
`and narrowed vessels make the size of the introducer
`sheet critical to the success of insertion. In those cases,
`the overall diameter of the dilation catheter and the
`guide wire together can be decreased if a groove is
`present along the entire catheter structure forwards of
`the outside of the body. By this means the guide wire is
`situatied within the circumferential groove in the dila-
`tion catheter enabling small size introducer sheets.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Like reference characters are used to identify similar
`features throughout the drawings, wherein:
`
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`5,102,403
`
`4
`FIG. 1 is a sketch of a distal end portion of a dilata-
`tion catheter of this invention showing a low friction
`saddle rider portion of the catheter merging into and
`surrounding a substantially parallel guide wire upon
`which the catheter distal end rides;
`FIG. 2 is a broken away fragmental sketch of the
`dilatation catheter functioning at a treatment site inside
`a body vessel at a stenosis treatment site; and
`FIGS. 3 to 10 are respective cross sectioned portions
`of the catheter at corresponding positions 3—3, etc.
`shown on FIG. 1.
`
`THE PREFERRED EMBODIMENT
`
`In the present invention , the catheter can be given
`special and critical properties by means of treatment of
`plastic materials from which the catheter is formed. For
`example,
`silicones,
`polyethylenes,
`polyurethanes,
`polyvinylchlorides and like synthetic plastic materials
`are readily formed into desired shapes by injection
`molding techniques, and may be after treated by ther-
`mal molding.
`The distal-rider end of the catheter afforded by a
`preferred embodiment of this invention also is molded
`from a suitable plastic material to have a gradual trans-
`formation along the axial length from an initial substan-
`tially round cylindric shape to a modified shape of the
`dilatation fluid lumen without abrupt changes from a
`generally cylindrical configuration of constant diameter
`for penetration of a guide wire into a gradually created
`second guide wire lumen formed inside the catheter
`body. The catheter body comprises an outer body skin
`defining an internal cylindrical dilation fluid lumen
`which is gradually conformed along a predetermined
`portion of the length into a riding saddle over the guide
`wrre.
`
`Along this length, which permits the guide wire to
`remain along its length with a substantially parallel axis
`with the catheter body, the catheter body wall gradu-
`ally progresses from a groove into a crescent shaped
`wall and internal lumen which at least partly surrounds
`the guide wire. The crescent closes toroidally about the
`guide wire to form a guide wire lumen which gradually
`extends toward the axis of the catheter body as the
`dilating lumen and outer configuration tapers into a
`terminal nose of solid plastic material. The generally
`cylindrical body shape is maintained at a constant diam-
`eter, with a cylindrical outer region positioned between
`the entry point of the guide wire and the nose for at-
`tachment of a circumferential dilatation balloon. Com-
`munication between the balloon and dilation fluid in the
`dilation lumen results from apertures in the body wall.
`Throughout the transition portion of the length cath-
`eter axial stiffness is maintained constant to facilitate
`entry and withdrawal of the catheter. Lateral bending
`elasticity is provided by the material and shaping of the
`lumen without substantially departing from the initial
`cylindric shape in order to facilitate bending in confor-
`mation with body vessels.
`The balloon or balloon mounting vicinity of the cath-
`eter may be radiation tempered. The C-shaped lumen
`may be reinforced by shaping or adding reinforcement
`means internal to the lumen at any points of critical
`stress under pressure caused by non-round lumen shap-
`ing. The tempered portions of the catheter can be
`treated to give a lateral bending modulus for similarly
`bending around curves without significant effect to the
`axial pushing stiffness required for positioning and with-
`drawing the catheter over a substantially parallel guide
`
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`Page 4 of 7
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`5,102,403
`
`5
`wire. Preferably the balloon at the distal end terminates
`near a solid plastic nose section tapered to provide less
`friction in penetrating a stenosis area for example to
`position the balloon for dilatation. Also preferably the
`balloon exterior perimeter tapers at both ends and has
`no disruptions.
`By having a common circumferential plastic body
`about the dilatation lumen cavity smoothly an progres-
`sively changing along the catheter length into an inte-
`rior guide wire lumen without abutments or steps in the
`catheter diameter, many problems of exerting distortion
`forces on the catheter or balloon surface for reaching
`treatment sites are eliminated. This all results in a more
`reliable,
`low friction, easy to insert balloon dilation
`catheter with a smaller diameter catheter in the region
`of the balloon than known in the prior art.
`As may be seen in FIGS. 1 and 2, the catheter of this
`invention is ideally suited for treament of cardiac dis-
`ease such as stenosis 32 of arterial vessel wall 31. The
`catheter 20 is inserted into the cardiovascular system
`typified by vessel 31 over a previously inserted guide
`wire 21 which runs parallel outside the catheter until it
`reaches a distal end region 23 for guiding the catheter to
`carry instrumentation such as a dilatation balloon lo-
`cated near its distal end to a treatment site 32.
`This catheter is of the type that as it nears the distal
`end 23, the guide wire 21 is gradually more and more
`encompassed and thus little friction between the guide
`wire and catheter is present to impede insertion or with-
`drawal of the catheter from a position outside the body.
`The catheter at region 2—2 of this embodiment is gen-
`erally of cylindrical shape having an internal inflation
`lumen 42 for fluid under pressure to expand a dilatation
`balloon in the distal end region 22. The catheter body is
`formed of a plastic material 26 having enough axial
`stiffness to push the distal end 23 over the guide wire 21
`and through small or stenosis restricted cardiovascular
`blood vessels into a treatment site without buckling or
`restricting the lumen 42 diameter, as aforesaid.
`The catheter throughout the distal end regions 4—4
`to 10—10, as shown in cross section in corresponding
`FIG. 4 through 10, undergoes smoothly progressing
`changes of shape of the wall 26 and lumen 42. The distal
`terminal end at FIG. 10 is of solid plastic which tapers
`to a penetration shape, which helps to advance the
`balloon more easily over an already positioned guide
`wire through high degree narrowings so that the bal-
`loon section of FIG. 9 may be placed into position for
`dilatation as shown in FIG. 2 within the blood vessel 31
`
`at stenosis site 32. The guide wire facilitates withdrawal
`of the catheter 20 along the guide wire 21 and allows its
`replacement with one having a larger diameter head
`end portion allowing a greater degree of dilatation.
`' Because of the easy insertion of the guide wire into the
`novel guiding lanes and of the limited length of guid-
`ance of the wire in the balloon possible with this inven-
`tion, initial treatment with a smaller balloon can readily
`be followed by a subsequent treatment with a larger
`balloon without the need for extensive guiding of the
`new catheter over a guide wire of more than double the
`length of the catheter.
`The smoothly changing shape of the catheter along
`its axial length at the balloon site critical to this inven-
`tion allows for an exchange of catheters without signifi-
`cant friction thus facilitating easy and fast pull back and
`advance of subsequent catheter structure over a guide
`wire. This can be visualized as related to the cross sec-
`tions of FIGS. 3 to 10. Thus the catheter plastic body
`
`6
`wall 26 becomes more deeply grooved at 40 for guiding
`the guide wire toward its final position, in this embodi-
`ment coaxial with the balloon as shown in FIG. 10.
`Thus guide wire 21 enters the catheter body axially
`from left to right (FIG. 1) through a groove, a crescent
`shaped semi-enveloping configuration, FIGS. 5 and 6,
`and then completely surrounded as in FIGS. 7 through
`10. Thus the catheter is transformed from a single lumen
`catheter into two lumens, adding one for the guide wire,
`all without changing substantially the outer cylindrical
`body configuration or its diameter. Furthermore, the
`guide wire gradually enters its new guiding lumen
`through several changes of guidance within a groove,
`and thus incurs no kinking or sharp bending as manda-
`tory for low friction removal or advance of the catheter
`over the guide wire.
`Also the lumen shape changes gradually within the
`catheter 20 as seen through the progression of FIGS. 3
`to 9, for this embodiment. Note that the balloon 90 has
`an outer skin 91 which is distendable in the presence of
`fluid in the inflating lumen 42 under increased pressure
`into an expanded diameter 90 shown in phantom view.
`This balloon is affixed to the outer cylindrical catheter
`surface at each end. That is critical in that high internal
`pressures are minimized and equalized about the joint,
`resulting in more reliability and operation at greater
`safety margins.
`The small diameter of the catheter 20, especially at
`zone 23, permits good lateral flexibility to bend around
`curves in the cardiovascular vessels. At the tip 100, a
`special material with some pliability is preferred for use
`in penetration of a stenosis region and this may be
`achieved by thermal or radiation treatment.
`The smooth progressive change of shape of the cathe-
`ter body 26 and its internal inflating lumen 25 to convert
`the single lumen catheter to one having an additional
`internal guide wire lumen 45 without substantially
`changing the direction of travel of the guide wire and
`the constant outer catheter diameter throughout is typi-
`fied by the sequence in the FIGS. 3 to 10. Thus the
`catheter body 26 of FIG. 3 becomes grooved at FIG. 4,
`with the body 26 and internal lumen 42 becoming cres-
`cent shaped at FIGS. 4 and 5. The internal lument 415
`is formed at FIG. 7 so that the balloon 90 may be glued
`or otherwise affixed to the outer cylindrical periphery
`of the catheter body 26 at 91 in FIGS. 2 and 8. The
`aperture 95 in the catheter body 26 of FIG. 9 permits
`balloon 90 to be dilated from fluid in lumen 42 to the
`
`inflated balloon condition 90. The lumen 42 is tapered
`toward the nose 100 shown in FIG. 10 to provide a low '
`profile solid penetrating probe end. During this entire
`transition, the catheter maintains its cylindrical shape
`and diameter.
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`Accordingly it is seen heretofore and in the appended
`claims that this invention has advanced the state of the
`art with those novel features defined in the claims for
`
`60
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`
`examplifying the nature and spirit of the invention.
`I claim:
`
`1. A catheter with distal end structure for forming a
`lumen to encompass and ride along a guide wire com-
`prising in combination:
`'
`a substantially cylindrical catheter body with an
`outer wall about a first lumen with the outer wall
`
`gradually changing in shape along the catheter
`body length toward the distal end from an entrance
`groove shaped as a path for guiding the wire in-
`wardly into the cylindrical body along the catheter
`length to form initially a crescent shaped catheter
`
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`5,102,403
`
`7
`body configuration partly surrounding the wire
`and which thereafter changes into a closed cylin-
`der wall surrounding a second guide lumen for
`encompassing the guide wire.
`2. The catheter distal end structure of claim 1
`
`wherein the outer wall of the catheter body over the
`length in which the catheter changes gradually and
`smoothly from a single lumen configuration to a two
`lumen configuration is substantially cylindrical in shape
`forming with the accompanying guide wire an exten—
`sion of the cylindrical catheter body.
`3. The catheter distal end structure of claim 1
`wherein the path of the wire through the groove and
`crescent shaped configuration into the second quide
`lumen is substantially parallel with the catheter body.
`4. The catheter distal end structure of claim 1
`
`wherein the catheter body consists of a plastic material
`having a substantially constant axial stiffness through-
`out the distal end structure length corresponding sub-
`stantially to that of the cylindrical catheter body, for
`permitting the catheter to be inserted into or withdrawn
`from body vessels of small dimension from a position
`outside the body.
`5. The catheter structure of claim 1 wherein the cath-
`
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`and a distal end instrument for movement inside the
`body to a treatment site;
`treatment means structure for inserting the guide
`wire means into the guide wire lumen confined to a
`short length low friction coupling region near the
`distal end of the treatment means at a linear portion
`having a substantially cylindrical body of substan-
`tially constant diameter, whereat
`the treatment
`lumen configuration changes in shape gradually
`along said coupling region to receive the guide
`wire and fully encompass the guide wire, and
`wherein the coupling region structure in the instru-
`ment for introducing the guide wire into the guide
`wire lumen without substantial change of direction
`of the guide wire from a parallel position alongside
`the treatment means body providing a smooth pro-
`gressive transition from cylindrical shape, to in-
`dented cylindrical shape provides a groove for
`guiding the guide wire,
`to substantially cresent
`shape for partly surrounding the wire, to the guide
`lumen.
`
`121A catheter for use with a companion guide wire
`having means for retention of the guide wire substan-
`tially within the catheter outer perimeter for insertion
`into a body vessel of restricted size, comprising in com-
`bination, a catheter body having a longitudinal groove
`internally indented in the outer periphery along a por-
`tion of the catheter length adapted to nest a guide wire
`therein and structure gradually changing the groove
`into a lumen within the catheter body for retaining the
`guide wire to thus produce a reduced outer perimeter
`for the catheter and guide wire.
`13. A catheter as defined in claim 12 having a guide
`wire nested in said groove thereby producing a substan-
`tially cylindrical outer perimeter of the combined cathe-
`ter body and guide wire.
`14. A combination of a guide wire and catheter
`adapted for insertion into a body vessel comprising in
`combination, a catheter body having a longitudinal
`groove along a predetermined length of the catheter
`near its distal end to be inserted into a body vessel of
`restricted size, said groove having a shape for receiving
`nested therein alongside the catheter body a substan-
`tially parallel guide wire, said groove changing into a
`lumen within the catheter for thereby receiving and
`surrounding the guide wire thereby to reduce an outer
`peripheral dimension of the catheter body-guide wire
`combination residing within the vessel.
`15. The method of inserting a guide wire into the
`distal end of a catheter so that the catheter may ride
`along the guide wire with low friction comprising the
`steps of:
`_
`producing a hollow cylindrical catheter with a cir-
`cumferential wall surrounding a lumen,
`gradually changing the circumferential wall configu-
`ration'to provide structure for inserting the guide
`wire to structurally change the circumferential
`wall along its length into a second lumen formed
`within the catheter with the initial cylindrical hol-
`low catheter circumferential wall changing along
`its length to form (a) an entrance groove for guid-
`ing the wire into a crescent shaped wall section
`partly surrounding the wire and '(b)
`transition
`structure closing the cresent to produce a guiding
`lumen about the wire, and
`>
`inserting a guide wire disposed substantially parallel
`with the catheter into the groove to follow the
`transition structure and enter the guiding lumen
`
`’PageGof?
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`eter body along the length of the change from one to
`two lumens thereby presenting the initial lumen in a
`crescent shape is reinforced to prevent the generally
`cylindrical catheter body from distorting in shape in
`response to internal fluid pressures used for dilatation.
`6. The catheter of claim 1 having a distal end portion
`formed with a substantially cylindrical outer wall along
`a predetermined length to which a balloon dilatation
`structure is affixed at two spaced positions along the
`cylindrical outer wall for dilation by means of fluid
`under pressure in the initial lumen.
`7. The catheter of claim 6 wherein the dilatation
`balloon structure when. dilated under fluid pressure has
`a cylindrical configuration tapering gradually down to
`the catheter body at two ends.
`8. The catheter of claim 1 with a body consisting of 40
`plastic having a characteristic of axial stiffness and a
`shear characteristic permitting the catheter body to
`readily bend around curves.
`9. A substantially cylindrical catheter body structure
`adapted to receive, direct, and envelop a substantially
`parallel disposed guide wire along a portion of the cath-
`eter’s length thereby forming an internal catheter guide
`wire lumen by changes of shape of the cylindrical cathe-
`ter body gradually over said length from a guide wire
`entry groove indented on the catheter outer surface into
`the internal lumen encompassing the guide wire.
`10. The catheter structure of claim 9 wherein the
`catheter body shape configuration about the lumen is
`constructed to preserve a substantially constant longitu-
`dinal stiffness along the catheter body.
`11. A therapeutic medical instrument for insertion
`into the body for treatment at an internal body site,
`comprising in combination:
`guide wire means for insertion into the body to a
`treatment site for guiding therapeutic means there-
`over into the treatment site;
`treatment means for insertion into the treatment site
`having a proximal end for emplOyment outside the
`body including treatment lumen structure provid-
`ing a communication path from outside the body to
`the treatment site, guide wire lumen structure
`within said treatment means for movement of the
`instrument along the guide wire to a treatment site,
`
`65
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`Page 6 of 7
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`9
`without departing substantially from the parallel
`disposition of the guide wire and catheter.
`16. The method of introducing a guide wire into a
`substantially cylindrical catheter body near its distal
`end while maintaining the diameter of the cylindrical
`catheter body substantially constant along its length to
`a position disposed around a guiding wire in a distal end
`region having a dilatation balloon structure positioned
`circumferentially about the catheter body perimeter,
`comprising the steps of:
`indenting the cylindrical catheter body to provide a *
`shaped groove along the length of the body for
`entry of the guiding wire, changing the groove in
`shape along said length into a. lumen surrounding
`the guide wire without a substantial change in di-
`ameter of the catheter body, and
`inserting a guide wire disposed substantially parallel
`to the catheter body gradually into the dilatation
`catheter body along its length to dispose the guide
`wire substantially concentrically within the bal-
`loon without substantially changing the diameter
`of the catheter body.
`17. The method of claim 16 further comprising the
`step of changing an internal dilation lument shape ini-
`tially disposed within the cylindrical catheter body
`from substantially circular to a non-round shape to
`accommodate the groove for insertion of the guide
`Wire.
`
`10
`
`15
`
`20
`
`25
`
`5,102,403
`
`10
`20. The method of claim 19 including the step of
`tapering the lumen means and the cylindrical body
`gradually along a distal end length of the catheter body
`beyond said predetermined length.
`21. The method of claim 19 including the steps of
`affixing a dilatation balloon structure over a length of
`the cylindrical body behind said predetermined length
`having a substantially constant diameter and producing
`aperture means to communicate with said lumen means
`for dilation of the balloon structure.
`22. The method of inserting into and withdrawing
`from a treatment site a catheter consisting of a plastic
`material comprising a dilatat