(12) United States Patent
`US 6,398,773 B1
`(10) Patent N0.:
`Bagaoisan et al. Jun. 4, 2002 (45) Date of Patent:
`
`
`
`
`U8006398773B1
`
`(54)
`
`(75)
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`ASPIRATION SYSTEM AND METHOD
`
`FOREIGN PATENT DOCUMENTS
`
`Inventors: Celso J. Bagaoisan, Union City; Hung
`V. Ha, San Jose; Mukund R. Patel,
`San Jose; Sivette Lam, San Jose; Mir
`Imran, Los Altos Hills, all of CA (US)
`
`1)]:
`WO
`W0
`
`3804849 A1
`WO/83/01894
`W0/89/01309
`
`2/1988
`6/1983
`2/1989
`
`OTI IER PUBLICATIONS
`
`(73)
`
`Assignee: Medtronic PercuSurge, Inc,
`Sunnyvale, CA (US)
`
`“Transluminal Angioplasty for the Treatment of Carotid
`Artery Stenoses” Freitag, et a1., VASA, Band 16, IIeft 1,
`1987.
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 26 days.
`
`“Pereutaneous Angioplasty of Atherosclerotic and Postsur-
`gical Stenosis of Carotid Arteries” J. Theron et 21]., AJNR,,
`62495—500, May/Jun, 1987,
`
`(21)
`
`(22)
`
`(60)
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`(51)
`(52)
`(58)
`
`(56)
`
`Appl. N0.: 09/591,733
`
`Filed:
`
`Jun. 12, 2000
`
`Related U.S. Application Data
`
`Division of application No. 09/026,013, filed on Feb. 19,
`1998, now Pat. No. 6,152,909, which is a continuation—in-
`part of application No 08/813,808, filed on Mar. 6, 1997,
`now abandoned, and a continuationiinepart of application
`No. 08/813,807, filed on Mar. 6, 1997, now abandoned, and
`a continuation-in—part of application No. 08/812,875, filed
`on Mar. 6, 1997, now Pat. No. 5,833,644, which is a
`continuation-in-part of application No. 08/650,464, filed on
`May 20, 1996, now abandoned.
`Int. Cl.7 ............................................... A61M 31/00
`U.S. Cl.
`...........
`.. 604/509; 604/28; 604/101.04
`
`Field of Search ............................ 604/509, 35, 28,
`604/40, 41, 42, 507, 508, 510, 264, 101.04,
`101.05, 523, 528
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`3,144,868 A
`4,299,226 A
`
`8/1964 Jasrtalevich
`11/1981 Banka
`
`Primary Examiner—Angela D. Sykes
`Assistant Examiner—Cris Rodriguez
`(74) Attorney, Agent, or Firm—Knobbe, Martens, Olson &
`Bear LLP
`
`(57)
`
`ABSTRACT
`
`Aspiration catheters and methods for the treatment of an
`occlusion in a blood vessel. These catheters and methods are
`especially useful in the removal of occlusions from saphe-
`nous vein grafts, the coronary and carotid arteries, arteries
`above the aortic arch and even smaller vessels. The catheters
`of the present invention are provided in either over-the-wire
`or in single operator form. Radiopaque markers are prefer-
`ably incorporated into distal ends of the catheters, and Visual
`markers are incorporated into the proximal end of the
`catheters, to facilitate their positioning within the body. The
`catheters are provided with varying flexibility along the
`length of the shaft, such that
`they are soft and flexible
`enough to be navigated through the vasculature of a patient
`without causing damage, but are stiff enough to sustain the
`axial push required to position the catheter properly and to
`sustain the aspiration pressures. Support mandrels and sup—
`port sheaths may also be added to impart additional strength
`to the length of the catheter.
`
`(List continued on next page.)
`
`7 Claims, 10 Drawing Sheets
`
`
`
`Page 1
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`Medtronic Exhibit 1019
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`US 6,398,773 B1
`Page 2
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`US. PATENT DOCUMENTS
`I
`.
`5f 984 Hussem 6‘ a1~
`2/, 3:: mmed‘e
`/,
`“F0
`3/ 986 Welkl et a],
`,
`,
`5/ 986 kcnscy
`,
`.
`9/ 986 Welkl et a1.
`,/ 987 Stlles
`Q,
`.
`,
`-
`9/ 988 IIorzewskl et al.
`,
`.
`12/ 988 Hawkins, Jr. et a].
`12,
`/ 988 Kensey
`,
`,
`,7
`,,
`l/ 989 Rlelschka
`,
`5/ 989 Patel
`/ 990 Fma
`3,.
`-
`,
`3/ 991 Patel
`,
`10/ 991 Ya
`,
`.
`8/ 992 Wright
`.
`,
`11/ 992 Don Mlchael
`,
`.
`11/ 992 AhmadI
`,
`.
`3/ 993 Don Mlchael
`,
`,
`.
`l
`10/ 993 Carbo et a1.
`11/ 993 Fischell
`,
`1/ 994 MISLlle et al.
`1/ 994 Corso, Jr. ct al.
`7/" 994 Slepian
`8/ 994 Don Michael
`
`44:53” A
`4,3682% 2
`’ _ a
`4 5/3 966 A
`’
`’
`4,589,412 A
`,
`,
`4,610,662 A
`,
`,
`,
`4 692 139 A
`_ _
`4,7/1,/77 A
`4,790,812 A
`4 790813 A
`,
`,
`4,794,928 A
`4,832,028 A
`,
`,
`4 911 163 A
`-
`5,000,143 A
`5,059,178 A
`5,135,484 A
`5,163,905 A
`5 163 906 A
`’
`’
`5,195,955 A
`,
`,
`,
`5,250,060 A
`5 263 959 A
`’ _ ’
`5,2/9,546 A
`5,281,200 A
`5,328,471 A
`5,342,306 A
`
`
`
`5,380,284 A
`5,403,274 A
`5,419,774 A
`5,423,742 A
`5,462,529 A
`5,476,450 A
`5 634 897 A
`9
`9 _
`5,662,6/1 A
`5,681,336 A
`5 688 234 A
`’
`’
`5,779,721 A
`5,823,996 A
`,
`5 833 644 A
`9
`a
`5,833,650 A
`5,879,361 A
`_
`5,938,6 /2 A
`5,954,745 A
`5 968 064 A
`’
`7
`6,022,336 A
`_
`6,050,9/2 A
`6 068 623 A
`’
`’
`6,135,991 A
`6,231,588 B1 *
`6 270 4,7 B1 *
`a
`a
`’
`
`1/1995 D011 Michael
`4/1995 Cannon
`5/1995 Willard et al.
`6/1995 'l'heron
`10/1995 Simpson et al.
`_
`.
`12/1995 Rugglo
`6/1997 Dance et a1.
`
`9/1997 Balbut et al.
`10/1997 Clement ct al.
`.
`.
`11/1997 Frisble
`
`7/1998 Nash
`10/1998 Sparks
`.
`.
`11/1998 ZadnoiAz121 et a1.
`
`11/1998 Imran
`3/1999 Nash
`8/1999 Nash
`,
`9/1999 Gertler et a1.
`10/1999 Selmon et a1.
`.
`.
`2/2000 Zadno-A2121 et al.
`,
`.
`.
`4/2000 LadnoiAz121 et al.
`.
`.
`5/2000 Zadno-Az121 et a1.
`.
`10/2000 Mum at al.
`5/2001 Zadno-Azizi
`
`1
`82001 B
`.
`t
`/
`agao‘sa“ 8' """"
`
`.
`
`* cited by examiner
`
`.. 606/200
`604 96 01
`/
`'
`
`Page 2
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`Jun. 4, 2002
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`US 6,398,773 B1
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`US. Patent
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`US. Patent
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`US. Patent
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`US 6,398,773 B1
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`1
`ASPIRATION SYSTEM AND METHOD
`
`RELATED APPLICATIONS
`
`This application is a divisional of U.S. application Ser.
`No. 09/026,013, filed Feb. 19, 1998, now U.S. Pat. No.
`6,152,909, which is a continuation-in-part of US. applica-
`tion Ser. No. 08/813,808, filed Mar. 6, 1997, abandoned, and
`US. application Ser. No. 08/813,807, filed Mar. 6, 1997,
`abandoned, and US. application Ser. No. 08/812,875, filed
`Mar. 6, 1997, now US. Pat. No. 5,833,644, which is a
`continuation in part of U.S. application Ser. No. 8/650,464
`filed May 20, 1996, abandoned, all of which are hereby
`incorporated by reference in their entirety.
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates to aspiration catheters for
`aspirating emboli, thrombi, and other types of particles from
`the vasculature of a patient, the apparatus being particularly
`well suited for aspiration Within saphenous vein grafts,
`coronary arteries, and similar vessels.
`2. Description of the Related Art
`Human blood vessels often become occluded or com-
`pletely blocked by plaque, thrombi, other deposits, emboli
`or other substances, which reduce the blood carrying capac-
`ity of the vessel. Should the blockage occur at a critical place
`in the circulatory system, serious and permanent injury, or
`even death, can occur. To prevent this, some form of medical
`intervention is usually performed when significant occlusion
`is detected.
`
`Coronary heart disease is an extremely common disorder
`in developed countries, and is the leading cause of death in
`the US. Damage to or malfunction of the heart is caused by
`narrowing or blockage of
`the coronary arteries
`(atherosclerosis) that supply blood to the heart. The coronary
`arteries are first narrowed and may eventually be completely
`blocked by plaque, and may further be complicated by the
`formation of thrombi (blood clots) on the roughened sur-
`faces of the plaques. Myocardial infarction can result from
`atherosclerosis, especially from an occlusive or near occlu-
`sive thrombi overlying or adjacent
`to the atherosclerotic
`plaque, leading to death of portions of the heart muscle.
`Thrombi and emboli also often result from myocardial
`infarction, and these clots can block the coronary arteries, or
`can migrate further downstream, causing additional compli-
`cations.
`
`Various types of intervention techniques have been devel—
`oped Which facilitate the reduction or removal of the block-
`age in the blood vessel, allowing increased blood flow
`through the vessel. One technique for treating stenosis or
`occlusion of a blood vessel is balloon angioplasty. Aballoon
`catheter is inserted into the narrowed or blocked area, and
`the balloon is inflated to expand the constricted area. In
`many cases, near normal blood flow is restored. It can be
`difficult, however, to treat plaque deposits and thrombi in the
`coronary arteries, because the coronary arteries are small,
`which makes accessing them with commonly used catheters
`difficult.
`
`Other types of intervention include atherectomy, deploy-
`ment of stents,
`introduction of specific medication by
`infusion, and bypass surgery. Each of these methods are not
`Without the risk of embolism caused by the dislodgement of
`the blocking material which then moves downstream. In
`addition, the size of the blocked vessel may limit percuta—
`neous access to the vessel.
`
`10
`
`b)LA
`
`I»O
`
`LuLA
`
`40
`
`(ALA
`
`60
`
`2
`In coronary bypass surgery, a more costly and invasive
`form of intervention, a section of a vein, usually the saphe-
`nous vein taken from the leg, is used to form a connection
`between the aorta and the coronary artery distal
`to the
`obstruction. Over time, however, the saphenous vein graft
`may itself become diseased, stenosed, or occluded, similar
`to the bypassed vessel. Atherosclerotic plaque in saphenous
`vein grafts tends to be more friable and less fibrocalcific than
`its counterpart in native coronary arteries.
`Diffuscly diseased old saphenous vein grafts with friable
`atherosclerotic lesions and thrombi have therefore been
`associated with iatrogenic distal embolic debris. Balloon
`dilatation of saphenous vein grafts is more likely to produce
`symptomatic embolization than dilatation of the coronary
`arteries, not only because of the difference in the plaque but
`also because vein grafts and their atheromatous plaques are
`generally larger than the coronary arteries to Which they are
`anastomosed. Once the plaque and thrombi are dislodged
`from the vein,
`they can move downstream, completely
`blocking another portion of the coronary artery and causing
`myocardial infarction. In fact, coronary embolization as a
`complication of balloon angioplasty of saphenous vein
`grafts is higher than that in balloon angioplasty of native
`coronary arteries. Therefore, balloon angioplasty of vein
`grafts is performed with the realization that involvement by
`friable atherosclerosis is likely and that atheroembolization
`represents a significant risk.
`Because of these complications and high recurrence rates,
`old diffusely diseased saphenous vein grafts have been
`considered contraindications for angioplasty and
`atherectomy, severely limiting the options for minimally
`invasive treatment. However, some diffusely diseased or
`occluded saphenous vein grafts may be associated with
`acute ischemic syndromes, necessitating some form of inter-
`vention.
`
`There is therefore a need for improved methods of treat—
`ment for occluded vessels such as saphenous vein grafts and
`the smaller coronary arteries which decrease the risks to the
`patient.
`
`SUMMARY OF THE INVENTION
`
`The present invention provides novel aspiration catheters
`for removing plaque, thrombi, emboli, and other types of
`obstructions from blood vessels. The present
`invention
`advantageously satisfies the need in the prior art by provid—
`ing a catheter adapted to be compactly utilized in even the
`smaller size blood vessels. It can also be easily adapted to
`provide efficient and speedy evacuation in larger size ves—
`sels. This system is compatible with more common therapy
`devices in widespread use today, and is designed for rapid
`evacuation and case of use.
`
`The catheters of the present invention are provided in
`either over-the-wire or in single operator form. The catheters
`are sized so as to be used in very small blood vessels.
`Radiopaque markers are preferably incorporated into the
`distal ends of the catheters to facilitate their positioning
`within the body; similarly, a marker may be placed on the
`proximal end of the catheter to aid in the insertion of the
`catheter in to the patient. The catheters are provided with
`varying flexibility along the length of the shaft, such that
`they are soft and flexible enough to be navigated through the
`vasculature of a patient without causing damage, but are stiff
`enough to sustain the axial push required to position the
`catheter properly and to sustain the aspiration pressures. A
`support mandrel may be incorporated into the catheter to
`provide additional strength, A support sheath is preferably
`
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`US 6,398,773 B1
`
`3
`included to prevent crushing of the aspiration lumen when
`the catheter is used in conjunction with valves, adaptors or
`other fittings.
`The catheters are preferably sized so as to allow the
`slidable insertion of a therapy catheter through the main
`aspiration lumen of the aspiration catheter. Alternatively, the
`therapy catheter can be built over the aspiration catheter. In
`either case,
`the aspiration and therapy catheters can be
`delivered simultaneously, saving valuable time during the
`procedure.
`One embodiment of the aspiration catheter of the present
`invention therefore comprises an elongate flexible tubular
`body having a proximal end and a distal end. The catheter
`body or shaft incorporates a reinforcement such as a metallic
`braid or coil or a polymer coil to provide strength and
`flexibility to the device. A main lumen extends the length of
`the tubular body, and an aspiration port at the proximal end
`of the catheter body is in fluid communication with the main
`lumen, such that aspiration pressure can be provided through
`the port and main lumen. The distal tip on the catheter is
`formed of a more flexible material than that used to form the
`rest of the catheter shaft. Markers are preferably incorpo-
`rated in to both the distal and proximal ends of the catheter
`to assist in positioning the catheter in the patient.
`The reinforcement can be formed from a variety of
`materials, including polymers, stainless steel, silver or gold
`plated stainless steel, ELGILOY, platinum, nitinol, or a
`combination thereof. The distal end of the catheter body is
`preferably more flexible than the proximal end, and this can
`be achieved by providing a braid or coil density at the distal
`end which is greater an the braid or coil density at
`the
`proximal end. At least one support mandrel may be used to
`provide the catheter with additional strength.
`The catheter’s main lumen is preferably sized to receive
`at least one separate catheter, such as a therapy catheter,
`which is slidably disposed herein. The inner diameter of the
`main lumen is preferably about 0.045."
`invention can
`The aspiration catheter of the present
`include a second lumen adjacent the main lumen which is
`adapted to receive a guidewire therethrough, The second
`lumen can extend substantially the entire length of the
`tubular body, or can extend less than 40 cm or less than 20
`cm in a proximal direction from the distal end of the body.
`The second lumen can contain a slit through a side wall to
`allow insertion and removal of the guidewire therethrough.
`In a preferred embodiment, the second lumen has an inner
`diameter of approximately 0.020" to receive a 0.014" diam-
`eter guidewire.
`The distal tip of the catheter can have at least one side port
`to facilitate aspiration. The distal tip can be tapered, blunt,
`or angled to create an oblique opening. The catheter pref-
`erably also comprises a valve in fluid communication with
`the main lumen,
`to control the application of aspiration
`pressure at
`the distal end of the device. The aspiration
`catheter of the present invention can also incorporate various
`coatings, such as hydrophilic or hydrophobic coatings, anti-
`thrombogenic coatings, or a combination thereof.
`the
`In another embodiment of the present
`invention,
`aspiration catheter comprises an elongate flexible tubular
`body having a proximal end and a distal end, a main lumen
`extending through the tubular body sized to receive at least
`one separate catheter which is slidably disposed therein, an
`aspiration port at the proximal end of the tubular body, the
`aspiration port being in fluid communication with the main
`lumen, and a tip on the distal end of the tubular body, the tip
`being formed of a more flexible material than that used to
`
`LII
`
`10
`
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`
`LuLA
`
`40
`
`(ALA
`
`60
`
`4
`form the tubular body. Again, the catheter can have a second
`lumen adjacent
`the first adapted to receive a guidewire
`therethrough, a specially shaped distal tip, and an optional
`valve in fluid communication with the main lumen.
`
`In yet another embodiment of the present invention, the
`aspiration catheter comprises an elongate flexible tubular
`body having a proximal end and a distal end, a main
`aspiration lumen through the tubular body, an aspiration port
`on the proximal end of the tubular body in fluid communi—
`cation with the main lumen, a therapeutic device attached to
`the distal end of the tubular body, and a tip on the distal end
`of the tubular body formed of a more flexible material than
`that used to form the tubular body itself. The therapeutic
`device can be an inflatable balloon and the catheter can
`include a separate inflation lumen for the balloon adjacent
`the main lumen.
`
`The aspiration catheter may be part of an aspiration
`system which comprises the aspiration catheter, an extension
`line having a valve or stopcock to control the delivery of the
`aspiration pressure, and a source of negative pressure such
`as a syringe.
`Accordingly, the catheters of the present invention pro-
`vide for very fast and efficient aspiration of the working area
`surrounding the occlusion in a blood vessel. The catheters
`can be utilized in a wide range of vessel diameters, including
`extremely small ones, are easy to use and can quickly and
`efficiently evacuate occlusions and debris, allowing the
`physician to restore normal blood flow in these vessels in a
`very short period of time.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective view of a human heart showing a
`saphenous vein graft used to bypass a portion of the coro-
`nary arteries.
`FIG. 2 is a side view of an over-the-wire aspiration
`catheter in accordance with the present invention.
`FIG. 3 is a cross section of the aspiration catheter of FIG.
`2, taken along line 3—3 in FIG. 2.
`FIG. 4 is a cross section of the aspiration catheter of FIG.
`2 showing a guide wire over which the aspiration catheter
`rides.
`
`FIG. 5 is a side view of a single operator type aspiration
`catheter in accordance with the present invention.
`FIG. 6 is a cross section of the proximal end of the
`aspiration catheter of FIG. 5, taken along line 6—6 of FIG.
`5.
`
`FIG. 7Ais a cross section of one embodiment of the distal
`end of the aspiration catheter of FIG. 5, taken along line
`777 of FIG. 5.
`FIG. 7B is a cross section of another embodiment of the
`distal end of the aspiration catheter of FIG. 5, also taken
`along line 7—7 of FIG. 5, showing a slit in the outer wall of
`the guidewire lumen through which the guidewire can be
`inserted and removed.
`FIGS. 8A—C are side views of the various embodiments
`of the distal end of the aspiration catheter of the present
`invention.
`
`FIG. 9 is a perspective view of an over-the-wire aspiration
`catheter and guidewire inserted into a saphenous vein graft
`in accordance with the present invention, with the vein graft
`shown partially cut away.
`FIG. 10 is a schematic view of an occlusion catheter
`apparatus for use in the method of the present invention;
`FIG. 11 is a schematic cross—sectional view of a distal
`portion of the catheter apparatus shown in FIG. 10.
`
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`US 6,398,773 B1
`
`5
`FIG. 12 is a perspective view of a valve which can be
`positioned at the proximal end of the catheter of the present
`invention to control aspiration,
`FIG. 13 is a side View of another embodiment of the
`over—the—wire aspiration catheter.
`FIG. 14 is a cross-sectional View of the aspiration catheter
`of FIG. 13, taken along line 14—14 in FIG. 13.
`FIG. 15 is a side view of another embodiment of the single
`operator type aspiration catheter.
`FIG. 16 is a cross—sectional View of the aspiration catheter
`of FIG. 15, taken along line 16716 in FIG. 15.
`FIG. 17 is a side View of an aspiration system, which
`includes an aspiration catheter, an extension line having a
`stopcock, and a source of aspiration pressure.
`FIG. 18 is a perspective View of an over-the-wire aspi-
`ration catheter having an occlusive balloon on its distal end
`and guidewire inserted into a saphenous vein graft in accor-
`dance with the present invention, with the vein graft shown
`partially cut away.
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`The present invention provides novel aspiration catheters
`for aspirating enrboli, plaque, thrombi or other occlusions
`from a blood vessel and methods of using same. The present
`invention is adapted for use in the treatment and removal of
`an occlusion in a blood vessel in which the occlusion has a
`length and a width or thickness which at least partially
`occludes the vessel’s lumen. Thus,
`the catheters of the
`present invention are effective in treating both partial and
`complete occlusions of the blood vessels. As used herein,
`“occlusion” includes both partial and complete occlusions,
`stenoses, emboli, thrombi, plaque and any other substance
`which at least partially occludes the vessel’s lumen.
`The method of the present invention can be used to
`provide aspiration with or without the need for a separate
`irrigation catheter and irrigation fluid.
`In the context of
`removing plaque, thrombi or other blockages from blood
`vessels,
`it has heretofore been proposed that an isolated
`“chamber ” surrounding the occlusion be created prior to
`attempting treatment, and that separate irrigation fluid be
`provided through an irrigation catheter to the chamber. It has
`been discovered that
`isolation of the occlusion is not
`required in some cases, and that
`the occlusion can be
`successfully removed through therapy and/or aspirating of
`the resulting debris without
`the need for delivery of a
`separate irrigation catheter and irrigation fluid in those
`vessels where certain pressure and fluid flow conditions
`exist, such as saphenous vein grafts, coronary arteries,
`carotid arteries and similar vessels.
`In non-bifurcated areas of the blood vessels, it has been
`discovered that fluid from the proximal portion of the same
`vessel acts as an infusion source. One can therefore occlude
`only the distal portion of the vessel to create a working area
`surrounding the occlusion and allow blood to flow from the
`proximal portion of the vessel into the working area. The
`working area surrounding the occlusion is aspirated through
`the guiding catheter or aspiration catheter. It should be noted
`that, as used herein, “proximal ” refers to the portion of the
`apparatus closest
`to the end which remains outside the
`patient’s body, and “distal ” refers to the portion closest to
`the end inserted into the patient’s body,
`The method and apparatus of the present invention can be
`used in any vessel of the body where the pressure is at least
`0.2 psi, and preferably, is about 1.2 psi, with a flow rate of
`
`LII
`
`10
`
`b)Ln
`
`5)O
`
`LuLA
`
`40
`
`(ALA
`
`60
`
`6
`at least 10 cc per minute. The method and apparatus are
`particularly suited for use in removal of occlusions from
`saphenous vein gafts, coronary and carotid arteries, and in
`other non—branching vessels having similar pressures and
`flow where a suitable worldng area can be created. A
`saphenous vein graft is depicted in FIG. 1. The graft 2 is
`used to bypass one of the occluded coronary arteries 4, and
`connects the aorta 6 to the coronary artery at a location distal
`the occlusion 8. Although the present
`invention will be
`described in connection with a saphenous vein graft,
`it
`should be understood that
`this application is merely
`exemplary, and the method can be used in other blood
`vessels as well.
`
`Apparatus Used With the Present Invention
`1. Guide Catheter and Occlusion Catheter
`To perform the method of the present invention, a guide
`catheter having a single lumen is first introduced into the
`patient’s vasculature through an incision made in the femo-
`ral artery in the groin and used to guide the insertion of other
`catheters and devices to the desired site. Following insertion
`of the guide catheter, a second catheter is inserted through
`the guide catheter and past the site of the occlusion. The
`catheter has an occlusive device, such as an inflatable
`balloon, filter or other mechanical occlusive device, attached
`at its distal end. The occlusive device should be capable of
`preventing the migration of particles and debris from the
`working area, either through total or partial occlusion of the
`vessel. Note that the occlusion of the vessel need not be
`complete. Substantial occlusion of the vessel can be suffi—
`cient for purposes of the present invention. The catheter
`should be sized so as to be slidable with respect to the
`therapy and aspiration catheters inserted over the catheter.
`The catheter is preferably made of metal such as stainless
`steel or nitinol, plastics, or composites. A guidewire having
`an occlusive device on its distal end is also suitable for use
`in the present method. The method of the present invention
`can be effectively carried out using a number of guidewires
`or catheters that perform the function of occluding the vessel
`and allowing for the slidable insertion of various other
`catheters and devices. The term “catheter ” as used herein is
`therefore intended to include both guidewires and catheters
`with these desired characteristics.
`A catheter suitable for use in the present invention is
`illustrated in FIGS. 10 and 11. The catheter apparatus 110 is
`generally comprised of four communicating members
`including an elongated tubular member 114, an inflatable
`balloon member 116, a core-wire member 120 and a coil
`member 122. The catheter apparatus 110 is preferably pro-
`vided with an outer coating of a lubricious material, such as
`Teflon.
`The body member 114 of the catheter apparatus 110 is in
`the form of hypotubing and is provided with proximal and
`distal ends 114A and 114B as well as an inner lumen 115
`extending along the tubular member 114. The balloon mem-
`ber 116 is coaxially mounted near the distal end 114B of the
`tubular member 114 by suitable adhesives 119 at a proximal
`end 116A and a distal end 116B of the balloon member 116
`as shown in FIG. 11. Proximal and distal tapered portions
`123A and 123B on either side of the balloon 116 preferably
`include adhesives. Proximal and distal adhesive stops 125
`and 126 contact the adhesives 119 to define the working
`length of the balloon 116. A radiopaque marker 127 is
`preferably located within the proximal
`tapered portion
`123A. A notch 128 in the tubular member 114 permits fluid
`communication between the lumen 115 and the balloon 116.
`A core—wire member 120 of the catheter 110 may be
`comprised of a flexible wire. The flexible wire 120 is
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`US 6,398,773 B1
`
`7
`preferably secured to the tubular member 114 within the
`lumen 115 by a combination of adhesives and crirnps 129
`(FIG. 11). The proximal end 120A of the flexible wire 120
`can have a transverse cross sectional area substantially less
`than the smallest transverse cross—sectional area of the inner
`lumen 115 of the tubular member 114. The flexible wire 120
`can also taper towards the distal end 120B to smaller
`diameters to provide greater flexibility to the flexible wire
`120. However, the flexible Wire 120 may be in the form of
`a solid rod, ribbon or a helical coil or wire or combinations
`thereof. As shown in FIG. 11, the distal end 120B of the
`flexible wire 120 is secured to a rounded plug 118 of solder
`or braze at the distal end 122B of the coil member 122. The
`coil member 122 of the catheter 110 may be comprised of a
`helical coil. The coil member 122 is coaxially disposed
`about the flexible wire 120, and is secured to the flexible
`Wire 120 by soldering or brazing.
`The balloon member 116 is preferably a compliant bal-
`loon formed of a suitable elastic material such as a latex or
`the like. The flexible coil 122 is preferably formed of a wire
`of platinum or gold based alloys. The flexible core—wire 120
`and the tubular member 114 are preferably formed of a
`superelastic nickel—titanium alloy.
`invention are preferably
`The catheters of the present
`provided with a coating on the outer surface, or on both the
`inner and outer surfaces. Suitable coatings include
`hydrophilic, hydrophobic and antithrombogenic coatings.
`Examples include heparin, silicone, polyurethane and PVP.
`These coatings can be applied using methods well known in
`the art.
`Additional details relative to the catheters described
`above are found in copending U.S. patent applications Ser.
`No. 08/813,023, filed Mar. 6, 1997, now US. Pat. No.
`6,270,477, Ser. No. 08/812,876, filed Mar. 6, 1997, now US.
`Pat. No. 6,068,623, entitled “Catheter for Emboli Contain-
`ment System” and “Hollow Medical Wires and Methods of
`Constructing Same”, respectively, and US. patent applica-
`tions Ser. No. 09/026,225, filed Feb. 19, 1998, Ser. No.
`09/026,357, filed Feb. 19, 1998, now US. Pat. No. 6,190,
`332, and Ser. No. 09/026,105, filed Feb. 19, 1998, now US.
`Pat. No. 6,228,072, entitled “Balloon Catheter and Method
`of Manufacture”, “Core Wire With Shapeable Tip”, and
`“Shaft for Medical Catheters”, respectively, all of which are
`hereby incorporated by reference in their entirety.
`2. Therapy Catheter
`Once the guiding catheter and second catheter have been
`properly positioned inside the vessel, the occlusive device at
`the distal end of the catheter is actuated to occlude the vessel
`distal to the existing occlusion to create a working area. A
`therapy catheter then is delivered to the site of the occlusion.
`The term “therapy catheter ” is meant to include any of a
`number of known devices used to treat an occluded vessel.
`For example, a catheter carrying an inflatable balloon for use
`in balloon angioplasty can be delivered to dilate the occlu-
`sion. Thermal balloon angioplasty includes the use of heat to
`“mold ” the vessel to the size and shape of the angioplasty
`balloon. Similarly, an intravascular stent can be delivered
`via a balloon catheter and deployed at
`the site of the
`occlusion to keep the vessel open. Cutting, shaving, scraping
`or pulverizing devices can be delivered to excise the occlu-
`sion in a procedure known as athereetomy. A laser or
`ultrasound device can also be delivered and used to ablate
`plaque in the vessel. Various thrombolytic or other types of
`drugs can be delivered locally in high concentrations to the
`site of the occlusion. It is also possible to deliver various
`chemical substances or enzymes via a catheter to the site of
`the stenosis to dissolve the obstruction. The term “therapy
`catheter ” encompasses these and similar devices.
`
`LII
`
`10
`
`b)Ln
`
`5)O
`
`LuLA
`
`40
`
`(ALA
`
`60
`
`8
`
`3. Aspiration Catheter
`After the therapy has been performed and the stenosis has
`been removed or reduced using any of the methods and
`apparatus described above, the working area is aspirated to
`remove fluid and debris. Aspiration pressure can be provided
`through the guide catheter if desired. A source of negative
`pressure is attached at the proximal end of the guide catheter
`to create reverse flow, and fluid and debris are aspirated
`through the guide catheter’s main lumen.
`Alternatively, an aspiration catheter or similar debris
`removing device is delivered to th