U.S. patent application number 10/187492 was filed with the patent office on 2003-05-01 for distal protection device.
This patent application is currently assigned to Bacchus Vascular, Inc.. Invention is credited to DuBrul, Will R., Evans, Michael.
Application Number | 20030083608 10/187492 |
Document ID | / |
Family ID | 23918526 |
Filed Date | 2003-05-01 |
United States Patent
Application |
20030083608 |
Kind Code |
A1 |
Evans, Michael ; et
al. |
May 1, 2003 |
Distal protection device
Abstract
The present invention describes a catheter suitable for
introduction into a tubular tissue for dissolving blockages in such
tissue. The catheter is particularly useful for removing thrombi
within blood vessels. In accordance with the preferred embodiments,
a combination of vibrating motion and injection of a lysing agent
is utilized to break up blockages in vessels. The vessels may be
veins, arteries, ducts, intestines, or any lumen within the body
that may become blocked from the material that flows through it. As
a particular example, dissolution of vascular thrombi facilitated
by advancing a catheter through the occluded vessel, the catheter
causing a vibrating, stirring action in and around the thrombus
usually in combination with the dispensing of a thrombolytic agent
such as urokinase into the thrombus. The catheter has an inflatable
or expandable member near the distal tip which, when inflated or
expanded, prevents the passage of dislodged thrombus around the
catheter. The dislodged portions of thrombus are directed through a
perfusion channel in the catheter, where they are removed by
filtration means housed within the perfusion channel before the
blood exists the tip of the catheter. Catheters that allow both low
frequency (1-100 Hz) vibratory motion and delivery of such agents
to a blockage and a method for using such catheters are disclosed.
A distal protection system comprising a braided structure capable
of moving from a contracted condition to an expanded condition and
adapted to inhibit particles from moving completely through the
braided structure when expanded is also disclosed.
Inventors: |
Evans, Michael; (Palo Alto,
CA) ; DuBrul, Will R.; (Redwood City, CA) |
Correspondence
Address: |
LYON & LYON LLP
633 WEST FIFTH STREET
SUITE 4700
LOS ANGELES
CA
90071
US
|
Assignee: |
Bacchus Vascular, Inc.
|
Family ID: |
23918526 |
Appl. No.: |
10/187492 |
Filed: |
July 1, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10187492 |
Jul 1, 2002 |
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09640499 |
Aug 16, 2000 |
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6508782 |
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09640499 |
Aug 16, 2000 |
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09005217 |
Jan 9, 1998 |
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6287271 |
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09005217 |
Jan 9, 1998 |
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08483071 |
Jun 7, 1995 |
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5713848 |
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08483071 |
Jun 7, 1995 |
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08320184 |
Oct 7, 1994 |
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5498236 |
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08320184 |
Oct 7, 1994 |
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08065470 |
May 19, 1993 |
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5380273 |
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08065470 |
May 19, 1993 |
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07885665 |
May 19, 1992 |
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Current U.S.
Class: |
604/22 ;
604/101.01 |
Current CPC
Class: |
A61B 17/22 20130101;
A61B 90/39 20160201; A61F 2/958 20130101; A61M 25/104 20130101;
A61M 2025/1093 20130101; A61B 2017/22084 20130101; A61B 2017/22067
20130101; A61M 2025/1052 20130101; A61B 17/22012 20130101 |
Class at
Publication: |
604/22 ;
604/101.01 |
International
Class: |
A61B 017/20 |
Claims
We claim:
1. A device for the removal of particles from a lumen within the
body comprising: an outer, hollow tube having a tube distal end; an
inner member housed within the tube and having an inner member
distal end positioned distally of the tube distal end; a porous
braided structure having a distal part secured to the inner member
distal end and a proximal part secured to the tube distal end; the
braided structure movable from a contracted condition to an
expanded condition by moving at least one of the tube and inner
member distal ends towards the other; and the braided structure
adapted to inhibit particles from moving completely through the
braided structure when in the expanded condition.
2. The device as in claim 1 where said braided structure has a
porous proximal side and a porous distal side.
3. The device a sin claim 2 wherein said distal side has smaller
pores than the proximal side.
4. The device as in claim 3 wherein said braided structure
comprises a section of a tubular, porous braided structure having
alternating first and second braided sections, said first braided
sections, corresponding to said distal side, having pore sizes
smaller than the second braided sections, corresponding to said
proximal side.
5. A device for the removal of particles from a lumen within the
body comprising: an outer, hollow tube having a tube distal end; in
inner member housed within the tube and having an inner member
distal end positioned distally of the tube distal end; a porous
mesh structure having a distal part secured to the inner member
distal end and a proximal part secured to the tube distal end; the
mesh structure movable from a contracted condition to an expanded
condition by moving at least one of the tube and inner member
distal ends towards the other; and the mesh structure adapted to
inhibit particles form moving completely through the mesh structure
when in the expanded condition.
6. The device as in claim 5 where said mesh structure has a porous
proximal side and a porous distal side.
7. The device as in claim 6 wherein said distal side has smaller
pores than the proximal side.
8. The device as in claim 7 wherein said mesh structure comprises a
section of a tubular, porous mesh structure having alternating
first and second mesh sections, said first mesh sections,
corresponding to said distal side, having pore sizes smaller than
the second mesh sections, corresponding to said proximal side.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation of application
Ser. No. 09/640,499 filed on Aug. 16, 2000, which was a
continuation of application Ser. No. 09/005,217, filed on Jan. 9,
1998, now U.S. Pat. No. 6,287,271 which was a continuation-in-part
of application Ser. No. 08/483,071, filed on Jun. 7, 1995, now U.S.
Pat. No. 5,713,848, which was a continuation-in-part of application
Ser. No. 08/320,184, filed on Oct. 7, 1994, now U.S. Pat. No.
5,498,236, which was a continuation of application Ser. No.
08/065,470, filed on May 19, 1993, now U.S. Pat. No. 5,380,273,
which was a continuation-in-part of application Ser. No.
07/885,665, filed on May 19, 1992, now abandoned, the full
disclosures of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is generally directed to removal of
blockage of tubular tissue and specifically directed to the
dissolution of intravascular thrombi.
[0004] 2. Description of the Background Art
[0005] It is well known that the formation of thrombi (clots) in
blood vessels is a serious medical malady. Thrombi are correlated
to the formation of plaque buildup in blood vessels and when
blockage occurs, it is more a result of the thrombi than of the
plaque buildup (which is usually referred to as atherosclerosis
when it is involved in arteries).
[0006] All thrombi need not be treated interventionally, but in
many instances thrombi do, in fact, become life threatening and
require removal or at least reduction in size. A thrombus is
primarily comprised of red blood cells and fibrin There are several
treatments which could be adapted for the removal of thrombi in
vessels which involve intravascular catheters. Most such
intravascular catheters have been designed primarily for plaque
removal and contain an element that vibrates at ultrasonic
frequencies. Representative of such atherectomy catheters are U.S.
Pat. Nos. 5,069,664, 4,920,954, 4,898,575, and 4,808,153. Some
involve cutting the plaque off of the wall of the vessel using a
cutting blade. Some may be adapted to facilitate removal of a
thrombus in a vessel. For example, DonMicheal, et al., in U.S. Pat.
No. 4,870,953, describes an intravascular catheter having a bulbous
head at its distal end which vibrates at ultrasonic frequencies. It
is suggested that such a tip might be useful for disintegrating a
thrombus. DonMicheal, et al., also teaches the discharge of a
radiographic contrast medium from the catheter tip to enable
visualization of the cleared vessel. A second cooling solution may
be circulated through the catheter to the tip to prevent
overheating of the bulbous tip. All the foregoing intravenous
catheters have their shortcomings. None are particularly adapted
for removing thrombi.
[0007] The use of laser catheters for treatment of thrombi is not
uncommon, and significant damage to vessels during this treatment
have been reported. The use of drugs for the primary dissolution of
these clots is extremely common and is often considered the primary
treatment of choice when a thrombus is present. These drugs are
referred to as thrombolytic agents (meaning clot dissolution or
decomposition). The most common thrombolytic agents (drugs) that
are used presently in the treatment of vascular thrombosis are such
agents as urokinase, streptokinase, TPA, leech saliva and other
such pharmaceutical clot dissolving agents. Significant problems
such as hemorrhagic complications, early rethrombosis, prolonged
infusion times, costs, significant failure rates, etc., are
persistent problems with the use of these pharmaceutical agents. To
overcome the aforesaid problems with drugs, an intravascular
spraying catheter may be placed in or near a thrombus and the clot
periodically sprayed (or pulsed) with a thrombolytic agent which
facilitates clot dissolution. Using intermittent spraying of
thrombolytic agents may enable the use of less drug over a shorter
time period to effect for thrombolysis when compared to the more
classical approach of allowing the drug to drip in or near the
clot. But even this approach requires excessive time and drug
amount. In addition, the use of pulsatile injections of
thrombolytic agents may result in pieces of the clot fracturing off
from the main body of the clot and causing an embolism which is a
danger faced by interventionalists performing this procedure. It
is, therefore, desirable to provide an improved catheter for
delivering thrombolytic agents which reduce the time and amount of
pharmaceutical agent required for thrombolysis and which reduces
the danger of embolism.
[0008] Stiles, in U.S. Pat. No. 4,692,139 (incorporated herein by
reference), describes a catheter for removing obstructions from
biological ducts which transmits ultrasonic vibrations to the
obstruction to facilitate lysis. Stiles' catheter has means for
administering a lysing agent and simultaneously administering
ultrasonic vibrations to obstructing material forward of the
catheter tip. The Stiles catheter has a vibrating probe which probe
(when the catheter is deployed within a vessel) projects from the
tip of the catheter. There is no teaching of any advantages to be
gained by either (a) vibrating the catheter (as opposed to a probe
housed within a catheter), or (b) using low frequencies
(frequencies below 1000 Hz). Further, Stiles teaches the use of
vibrational frequencies in the range "of at least 60 KHz." The
vibrational frequency employed to effect lysis is an important
issue. It is noted that at the frequencies suggested by Stiles'
teaching, the wavelength of ultrasound in the probe is 1 = v f <
1000 f < 1000 60 , 000
[0009] or .lambda.<{fraction (1/60)} foot. Thus, in Stiles'
catheter there are normally many wavelengths of ultrasound between
the ultrasonic source and the probe tip. Wherever the probe tip
touches the surrounding aspiration tube walls and/or aspirate,
energy will be lost due to heating. Thus, it is difficult or
impossible to control the amount of ultrasonic vibratory energy
reaching the tip of the probe. Depending on the amount of loss of
ultrasonic vibrational energy that occurs along the length of the
probe (which, of course, depends on the amount of aspirate in the
aspirator tube and the amount of mechanical contact between the
probe and the surrounding walls) the energy actually delivered to
tissue at the probe tip may either ablate or weld tissue, emulsify
an obstruction or be insufficient to have any effect on an
obstruction.
[0010] Lower frequency vibrations (less than 100 Hz) have
wavelengths greater than one foot. The amplitude and, therefore,
the energy of the low frequency vibration delivered to the tip of a
catheter is much more predictable at the lower frequencies and
enable more accurate dosimetry. This is because the vibratory loss
to surrounding tissue is due to uniform frictional losses along the
length of the elongate member (inserted catheter). Stiles' probe,
which vibrates at ultrasonic frequencies as noted above, is housed
within an aspiration tube where it may unpredictably be loaded by
contact with any aspirate that may be present or the surrounding
catheter walls. That is, the undesirable coupling of vibratory
energy out of the Stiles' probe is unpredictable. It would be
desirable to provide an interventional catheter having a structure
wherein the vibrating element contacts the tissue along its entire
length.
[0011] All of the prior art thrombolysis catheters have specified
ultrasonic frequencies (above audible frequencies) when advocating
adjunctive vibratory waves to assist thrombolysis. Perhaps this is
due to the availability of compact solid state crystals that
oscillate or may be driven at these frequencies. Perhaps it is the
belief that these frequencies assist in "emulsifying" an
obstruction such as a thrombus. Whatever the reason, the present
teaching surprisingly shows that the application of low frequency
mechanical vibrations facilitate thrombus disintegration. Even more
surprisingly, this is true even in the absence of an exogenous
lysing agent.
SUMMARY OF THE INVENTION
[0012] While the invention is best understood and taught by making
reference to the invention in context of a particular application
such as the treatment of vascular thrombosis, it is the object of
the present invention to provide a catheter (herein alternatively
referred to as a "motion catheter" or a "vibrating catheter") that
can be placed in a blocked lumen in the body and, by either
utilizing the motion of the catheter alone or the catheter motion
in combination with the dispensing of a medicament suitable for
dissolving such blockage, dislodge or more preferably, dissolve
said blockage. This motion catheter, which may be simply a moving
wire, can be used alone for blockage removal or with a lysing agent
to dissolve the blockage. Most preferably, both motion and
dispensing are used in combination to effect blockage removal.
[0013] The objects of this invention are achieved, in general, by
providing a vibrating wire, or alternatively, a vibrating catheter
that has an open lumen for delivery of said lysing agents. The
vibrating catheter may have one or more directional channels for
delivery of a lysing agent which channel(s) are attached to a pump
so that delivery of said lysing agent can be controlled with
respect to delivery time and delivery rate of the lysing agent.
[0014] Because blockage of lumens in the body are often times
visualized with image enhancement devices, the catheter of the
present invention is conveniently placed by means of fluoroscopy,
ultrasound or the like. The motion catheter may be placed in the
body in any tubular tissue in proximity to said blockage so that
the motion of the catheter will dislodge or preferably dissolve the
blockage.
[0015] A specific application of the aforementioned motion catheter
is the dissolution of blood clots or thrombi with or without the
use of a lysing/thrombolytic agent such as urokinase, streptokinase
or a similar lysing agent. If the distal tip of the motion catheter
is placed in juxtaposition to a blood clot (proximal, distal,
inside or adjacent to the clot), the low frequency (1-5000 Hz)
motion of the catheter facilitates the dislodgment by mechanical
agitation of the thrombolytic clot. Dissolution may be achieved if
the vibrating catheter also dispenses a thrombolytic agent. Usually
the thrombi are located in an artery. As a thrombus dissolves, it
is desirable that the tip of the motion catheter be moved (with
regard to its original placement/location) to keep the tip in
juxtaposition with the clot and to further facilitate the
dissolution of the thrombi.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic view of a preferred embodiment of the
motion catheter of the present invention.
[0017] FIG. 2 is a cross-sectional view of the distal treatment tip
of the catheter of FIG. 1 along line 2-2.
[0018] FIG. 3 is a cross-sectional view of the motion catheter of
FIG. 1 taken near the proximal end of the catheter along line
3-3.
[0019] FIG. 4 is a longitudinal cross-sectional view of the
proximal end of the motion catheter of FIG. 1 taken along line
4-4.
[0020] FIG. 5 is a schematic perspective view of the preferred
embodiment of the motion catheter of the present invention wherein
the distal treatment tip of the catheter of the present invention
is embedded in the obstruction (shown in cross-section) causing
blockage of the lumen.
[0021] FIG. 6 is a schematic perspective of the preferred
embodiment of the present invention shown in FIG. 5 wherein the
motion catheter passes through or around the obstruction and the
lysing agent (if required) emanates from the most distal portion of
the catheter.
[0022] FIG. 7 is a schematic perspective view of the preferred
embodiment of the present invention shown in FIG. 5 wherein the
distal treatment tip of the catheter protrudes through the
clot/obstruction and the lysing agent sprays inside the clot and
both proximal and distal to the clot.
[0023] FIG. 8 is a cross-sectional view of the preferred embodiment
of the present invention in FIG. 5 wherein the distal treatment tip
of the motion catheter is located proximal to the obstruction and
the spraying lysing agent delivered from the tip in a direction
parallel to the long axis of the catheter.
[0024] FIG. 9 is a perspective view of the distal tip of the
preferred embodiment of the present invention shown in FIG. 5
wherein the motion catheter is rotating or oscillating in a
to-and-fro motion while the lysing agent is being dispensed.
[0025] FIG. 10 is a cross-sectional view of the preferred
embodiment of the present invention shown in FIG. 5 wherein the
lysing agent is dispensed by holes in the distal tip and is
directed within and/or under the body of the obstruction.
[0026] FIG. 11 is a cross-sectional view of a second preferred
embodiment of the present invention wherein an inflatable vessel
occluder near the distal tip of the catheter blocks the flow of
blood around the outside of the catheter thereby forcing the blood
to flow through a particle filter housed within a perfusion channel
within the catheter.
[0027] FIG. 12 illustrates a prospective view of an aspiration
embodiment of the present invention.
[0028] FIG. 13 illustrates the distal end of an aspiration
embodiment of the present invention.
[0029] FIG. 14 illustrates an alternate embodiment of an aspiration
device of the present invention.
[0030] FIG. 15 illustrates an additional alternative embodiment of
an aspiration device of the present invention.
[0031] FIG. 16 illustrates the use of a balloon mechanism with the
catheter of the present invention.
[0032] FIGS. 17 through 20 illustrate various embodiments of a
filter trap with and without the use of the aspiration device of
the present invention.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0033] Turning now to FIG. 1, a preferred embodiment of the motion
catheter of the present invention is generally indicated at the
numeral 10. The catheter 10 has a proximal end 11 and a distal or
treatment end 12. The proximal end 11 matingly engages a vibrating
member 16 which vibrating member 16 is driven by an oscillator 15.
The catheter 10 may have one or more lumens extending from the
proximal end to the distal end. One lumen, which is optional, is a
guidewire lumen which enters the catheter through the guidewire
lumen port 13 and exits the catheter through the distal tip 12. A
second lumen, having an entry port generally indicated at 14,
extends the length of the catheter to the distal tip 12 and is used
as a conduit for transporting a lysing agent or other compatible
fluid (e.g., saline) from a reservoir (not shown) to the distal tip
12 of the catheter 10.
[0034] The distal tip 12 of the catheter 10, which may be
radiopaque, is shown in cross-section in FIG. 2. A lysing agent
lumen 21 extends the length of the catheter connecting the lysing
agent entry port 14 with dispensing holes near the distal tip 12.
There may be one or more holes surrounding the tip 12, which holes
are in fluid communication with the lysing agent lumen 21. The
guidewire lumen 22, which is optional, enables the use of the
catheter with a guidewire. The guidewire (not shown) may be
introduced into the vessel in which the catheter is to be inserted
for removing blockage. The abnormal narrowing or constriction of a
passage or lumen such as results from a clot lodged in a blood
vessel is called a stenosis. The guidewire is advanced, usually by
means of x-ray, until it reaches the point of stenosis. The
guidewire may then be either forced through the stenosis or it may
terminate at the stenosis. The catheter 10, may then be inserted
over the guidewire and advanced so that the distal tip 12 of the
catheter is in juxtaposition with the blockage. While for many
applications the presence of a guidewire lumen is necessary, for
other applications it is not required. A pump (not shown) may be
used to force a lysing agent into the lysing agent lumen 21 through
the entrance port 14.
[0035] It is known in the prior art to be advantageous to have an
element within an intravascular catheter capable of vibration at
high frequencies. Such catheters normally require the element to
vibrate at ultrasonic frequencies to effect the result desired.
Accordingly, such catheters employ a titanium wire coupled to an
ultrasonic generator such as a piezoelectric crystal which causes
the wire to vibrate longitudinally at ultrasonic frequencies. In
these instances, the ultrasonic energy is transferred to the medium
surrounding the vibrating element and is used to cause cavitation
at the tip of the catheter, which cavitation may cause the
disruption of the blockage. Alternatively, an ultrasonic transducer
may be placed at the tip of the catheter to emit ultrasonic waves
laterally therefrom and receive reflections from the walls of the
surrounding vessel thereby providing an ultrasonic image of the
vessel wall. The use of ultrasonic frequencies produces heat, both
along the wall of the catheter and at the tip which requires a
cooling fluid. In addition, titanium must be used in order to
prevent fracture of the wire.
[0036] In the present invention, the entire catheter 10 is coupled
to a source of vibrational energy 16 driven by an oscillator 15
operating in the range of 2 to 1000 oscillations per second. These
low frequency vibrations transmit along the catheter to its distal
tip 12 providing a mechanical motion of the tip. Such mechanical
motion can be used to mix a lysing agent with a blockage near the
distal tip. The vibrating agent 16 (FIG. 1) is inserted into the
proximal end of the motion catheter 10 as shown in greater detail
in FIG. 4. The proximal end 11 of the catheter 10 matingly engages
the oscillating element 16. The oscillating element 16 reciprocates
in the direction of the long axis of the catheter 10.
Alternatively, the oscillating element 16 may rotate to-and-fro
causing a back and forth rotary motion along the wall of the
catheter which is translated to the tip. Or a to-and-fro motion may
be used in combination with a back and forth translational motion
to effect a wobbling motion at the tip. The use of such motion in
combination with the dispensing of a medicament such as a lysing
agent at the tip of the catheter is illustrated in FIGS. 5 through
10.
[0037] In FIG. 5, the distal tip 12 of catheter 10 is shown
advanced into a blood vessel 55. The blood vessel inner wall 55 is
surrounded by tissue generally indicated by 57. An obstruction 51
in the vessel is penetrated by the distal treatment tip 12 of the
catheter 10. Once tip 12 of the catheter 10 is within the
obstruction 51 (such as a blood clot) a lysing agent 53 is
dispensed from the holes 58 near the tip of the catheter by means
of pumping the lysing agent 53 from a reservoir (not shown) through
the lysing agent lumen 21. At the same time, the mechanical motion
of the tip, generally indicated at 54, is induced in the distal tip
of the catheter by means the vibrating element 16. The combination
of lysing agent 53 emanating from holes 58 in the distal tip 12 of
the catheter 10 in combination with the vibratory motion 54 of the
distal tip of the catheter assists in the penetration of the lysing
agent into the obstruction 51, and provides an advantage over prior
art.
[0038] Alternatively, the distal tip 12 of the catheter 10 may be
inserted into the blockage 51 and passed completely therethrough,
as shown in FIG. 6, so that the very distal-most portion of the
distal tip 12 extends beyond the obstruction 51. In such an event,
motional waves 54 may be used in combination with the release of a
lysing agent 53 from holes 58 in the distal tip to facilitate
dissolution of the blockage 51. This may be particularly
advantageous in the event that plaque 56 is covering a portion of
the wall 55 of the vessel.
[0039] As shown in FIG. 7, it is also possible to have a plurality
of holes 58 dispensing the lysing agent 53, both distal to the
obstruction 51 and interior to the obstruction. Such a combination
of vibrational motion and spraying of lysing agent into the
blockage facilitates the rapid disruption of the blockage 51.
[0040] In FIG. 8, the distal tip 12 is advanced until it is in
juxtaposition with the proximal end of the blockage 51. When the
distal tip is in position, the vibrational waves 54 in combination
with the release or spraying of lysing agent 53 affect the
dissolution of the blockage 51.
[0041] Up until now, we've been referring primarily to vibrational
motion in the tip of the catheter that is axial oscillatory motion
generally in the direction of the axis of the catheter. FIG. 9
shows a rotary motion which may be imparted to the tip of the
catheter by applying an oscillating rotary motion to the proximal
end of the catheter. The arrows in FIG. 9 show the rotation of
various elements of the tip of the catheter with respect to
adjacent elements of the catheter. The catheter 10 is a flexible
structure and these rotational waves can travel down the catheter
changing direction. Such rotary motion, particularly when the tip
12 is embedded within the blockage 51, may be particularly
advantageous for facilitating the penetration of lysing agent 53
sprayed from the holes 58 in the distal tip 12 of the catheter 10.
The rotational arrows are generally indicated at 58.
[0042] FIG. 10 shows a translational motion which can be used in
combination with the rotary motion of FIG. 9, which combination of
motions may cause the tip 12 of the catheter 10 to "wobble" or
"wiggle" causing mixing and enabling the lysing agent 53 to more
rapidly permeate the obstruction 51 facilitating dissolution
thereof.
[0043] During the dissolution process, fragments of the obstructing
thrombus may break loose and obstruct the vascular system at once
or more points remote from the original obstruction. A second
preferred embodiment of the catheter of the present invention which
is especially designed to prevent the dissemination of such
fragments to other points in the vascular system is shown in FIG.
11. In this second preferred embodiment the catheter 10 has a
coaxial inflatable member 59 on the outer surface thereof between
the holes 58, through which holes lysing agent (not shown) is
sprayed, and the distal tip 12 of the catheter 10. A perfusion
channel (not shown) housed within the body portion of the catheter
10 is coextensive with the portion of the catheter between
fenestrations 60 and 61 in the outer wall of the catheter 10
providing fluid communication therebetween. Blood enters the
perfusion channel (not shown) through the proximal fenestration 60
in the direction indicated by arrow 60(a). Any fragments of
thrombus entrained in the blood as the blood enters the proximal
fenestration 60 will pass into the catheter perfusion channel. A
particle filter (not shown) is deployed within the perfusion
channel to remove such fragments before the blood exits the
perfusion channel through the distal fenestration 61 as indicated
by arrow 61(a). The filter (not shown) is in-line with the
perfusion channel connecting fenestrations 60 and 61 and can be a
polymeric or metallic mesh or "birds nest" or a filter of the type
used to remove fat cells from an aspirate described in U.S. Pat.
No. 4,834,703 to Dubrul, et al., (incorporated herein by
reference). Such a filter must be in-line with the perfusion
channel and coextensive with at least a portion thereof to
effectively remove fragments of thrombus and any other unwanted
particulate debris from the perfusate 60(a) and 61(a).
EXAMPLE
[0044] To prove evaluate the effectiveness of the present
invention, an in vitro experiment was performed to evaluate the
advantage, if any, of using the motion catheter to disburse clots
rather than existing technology. Blood clots were created in a test
tube. The weight of each clot was measured prior to
experimentation. The clots were then treated with urokinase at a
rate of 5000 IU/ml for 5 minutes to a total of 15,000 IU. The clot
(thrombus) weights were measured initially and finally to determine
the amount of lysing that had taken place. One of the groups (Group
1) was used as a control. Nothing was done to the Group 1 thrombi
except initial and final weighing. Another group (Group 2) was
treated with the same amount of lysing agent, but the lysing agent
was dispersed through the motion catheter while the catheter was
being very slowly vibrated, the catheter was placed proximal to the
clot in similar fashion as was the aforementioned group. In Group
3, the motion catheter was placed in the clot as in Groups 1 and 2,
but the urokinase was pulsed into the clot and no motion was
applied to the system. In Group 4, the lysing agent was pulsed into
the clot as in Group 36, but a slow (low frequency) vibratory
motion was applied to the motion catheter Group 5 clots were
treated with saline and slow vibration. In Groups 2, 4, and 5
(Groups with a motion applied to the motion catheter) the amount of
lysing of the clot/thrombus was greatly increased as determined by
the difference in weight of the clot/thrombus before and after the
one hour treatment. Those results are tabulated in Table 1 where
the percentage of lysing is the difference between the initial and
final weight of the clots divided by the initial weight, the
quotient multiplied .times.100.
1 TABLE I Group 1 4.5% Lysing Group 2 68% Group 3 26% Group 4 45%
Group 5 45%
[0045] From the foregoing data it is clear that low frequency
vibration with administration of a lysing agent (Group 2) give the
best results. Surprisingly, the Group 5 clots (no lysing agent)
that were subjected only to a low frequency (1-1000 Hz) vibrating
member in the presence of saline exhibited substantial dissociation
under the conditions of the experiment. This suggests that the
introduction of a simple intravascular wire or similar elongate
member vibrating at lower frequencies (<1000 Hz) into a blocked
vessel may be useful for disrupting clots.
[0046] The invention will now be described with respect to FIGS. 12
through 15. An aspiration device generally indicated by the numeral
100, is shown with respect to FIG. 12. The aspiration device 100
includes a suction mechanism 102 located at the proximal end 11 of
the motion catheter 10. The aspiration device 100 additionally
includes an outer sleeve 104, as shown more clearly in FIG. 13. The
outer sleeve extends from the proximal end 11 to the distal end 12
of the device 10.
[0047] During, after, or before the obliteration of the atheroma or
other obstruction in the blood vessel, small particles represented
by fragments 106 exist within the blood vessel. As is well known,
these fragments can cause extreme health difficulties such as
stroke, ischemia, collateral vessel blockage and the like. It is
thus, advantageous to remove such particles 106 from the blood
vessel. The aspiration device 100, which activated, causes a
suctioning, or low pressure, to be developed at the proximal end
drawing blood in a direction of the arrows 108. The aspiration
device is activated by the suction mechanism 102. The suction
mechanism 102 includes a chamber 110 and a plunger 112. When the
plunger 112 is pulled away from the chamber 110, a low pressure
area or vacuum is created in a lumen of the catheter 10. As noted
below, this causes the blood flow to proceed from the distal end to
the proximal end. Other vacuum sources such as a mechanical pump,
or an electro-mechanical pump, may also be used as the suctioning
mechanism 102, to create the low pressure area.
[0048] It will also be appreciated that, while it is not shown in
FIG. 12, a third port could be added comprising an injection port.
The injection port, while not shown here, is shown in the earlier
filed drawings connected with this matter, specifically FIG. 1 of
U.S. Pat. Nos. 5,498,236 and 5,380,273. Additionally, the motion
catheter 10 may include distal end 12 having an infusion port such
as infusion port 61, as described with reference to FIG. 11 of the
above identified patents.
[0049] It will be appreciated that the injection port and the
aspiration port may be activated independently and simultaneously.
Thus, while fluid may be moved up and through the catheter from the
distal end to the proximal end, it may also be appreciated that
fluid may also be moved down and through the proximal end 11
through the distal end 12 using the injection port. In this way,
while simultaneously aspirating, a fluid such as a medicament, for
example saline or sterile water, may be injected into the patient's
blood vessel simultaneously with the aspiration process.
Additionally, it will be appreciated that fluid of any kind can be
moved in either direction through the catheter using aspiration and
infusion including fluid such as a contrast fluid.
[0050] It will be appreciated that FIG. 11 of the above identified
patents, noted particularly at U.S. Pat. No. 5,498,236, col. 6,
lines 50 through 57, and at col. 6, line 65 through col. 7, line 12
and U.S. Pat. No. 5,380,273, col. 6, line 58 through col. 7, line
25, specifically disclose polymeric, metallic mesh, or birds nest
filter described with respect to aspiration and the like. A filter
such as the one described above, or filter cartridge as
specifically referred to in U.S. Pat. No. 4,834,703, may be
inserted within the outer sleeve 104 coaxially with the catheter.
The filter cartridge, or filter, traps the particulate matter or
particles 106, thereby removing the same from the blood vessel and
consequently from the blood stream.
[0051] As shown in FIGS. 12 and 13, the motion catheter 10 may be
activated during aspiration. It may be desirable to remove
particulate matter 106 as the tip is in motion to either vibration
or rotation. Alternatively, the aspiration device 100 may be
activated both after and before activation of the motion
catheter.
[0052] With respect to FIG. 14, there is shown another embodiment
of the aspiration device 100, wherein the distal end 12 of the
motion catheter 10 includes the distal end having fenestrations. In
this embodiment, the in-line polymeric filter and/or filter
cartridge would be inserted within the motion catheter itself to
trap the particulate matter 106. The fenestrations 114 are shown in
FIG. 14 as being generally rectangular in shape. It will be
appreciated that a variety of shapes, sizes, and styles may be
appropriate depending upon the particular function, blood flow, and
level of force of the aspiration device 100. Similarly to the
previously discussed embodiment shown in FIG. 13, the embodiment
shown in FIG. 14 having fenestrations 114, allow the particulate
matter to enter the fenestrations as a result of the low pressure
being created by the activation of the aspiration device 100, and
thereby removed by the blood stream through the in-line polymeric
filters as discussed above.
[0053] With respect to FIG. 15, there is shown a third embodiment
of the aspiration device 100 in accordance with this invention. In
the aspiration device of FIG. 15, the outer sleeve 104 includes an
occluding mechanism 116 which prevents blood from preceding around
the occluding mechanism 116 and causes blood flow to enter the
proximal end of the outer sleeve 104. Similar to the previously
discussed embodiments of FIGS. 13 and 14, the occluding mechanism
116 operates to force blood flow to an area where an in-line
polymeric filter or filter cartridge may trap the particulate
matter 106, thereby removing it from the blood vessel and
consequently the blood stream.
[0054] It will be appreciated that a variety of other filters not
described herein may be used. For example, the filters may comprise
a variety of different shapes and sizes and may be located in
slightly different positions on the catheter.
[0055] The occluding mechanism 116 comprises an exemplary
embodiment, an angioplasty type balloon which is selectively
inflated to cause a blockage in the blood vessel as shown clearly
in FIG. 15. Other occluding mechanisms of course are within the
scope and spirit of this invention.
[0056] Also, it will be appreciated that an occlusion balloon, or
centering balloon, may also be used in place of the angioplasty
type balloon. The occlusion or centering balloon is distinguished
from the angioplasty balloon because it does not inflate to a
predetermined sized. Rather the occlusion balloon continues to
increase in size the more it is inflated. Also, the occlusion
balloon conforms itself to the shape and size of the inner vessel
wall. In some instances, it may well be preferable to use the
occlusion balloon as opposed to the angioplasty type balloon. It
will be understood herein that when referring to the angioplasty
balloon below, that other types of balloons including the occlusion
or centering balloon, may well be substituted in its place.
[0057] Similarly with respect to FIGS. 13 and 14, the aspiration
device of FIG. 15 may be used before, after, or during activation
of the motion catheter 10.
[0058] With respect to FIG. 16, there is shown another embodiment
of the motion catheter 10 in accordance with this invention. In
this embodiment, the motion catheter 10 includes an
angioplasty-type balloon 118 at the distal end 12. The
angioplasty-type balloon 118 is formed, as is conventional in the
field and more particularly as shown and described in U.S. Pat.
Nos. 4,922,905, 4,838,268, 4,808,164, and 4,707,670, which are
specifically incorporated herein by reference, and represents a
typical angioplasty-type balloon. As noted above, an occlusion
balloon such as those identified in U.S. Pat. Nos. 5,637,086,
5,222,970, 5,074,869, and 4,130,119, which are also specifically
incorporated herein by reference, may be substituted for the
angioplasty-type balloon.
[0059] In the embodiment shown in FIG. 16 showing the angioplasty
balloon 118, the motion catheter may be activated before, during,
or after, balloon expansion. It is believed that such motion of the
angioplasty balloon is particularly useful in relieving the blood
vessel obstruction. It will be appreciated that the various
elements, shown in FIGS. 12 through 15, may be combined or used
alternatively with the embodiment shown in FIG. 16 within the
spirit and scope of this invention. However, it is not necessary
for the beneficial effects and advantages of the embodiment shown
in FIG. 16 to provide the alternative structures shown and
described in such combinations.
[0060] With respect to FIGS. 17 through 20, there is shown an
alternate embodiment of the motion catheter device 10 having a
distal end 121 and a coaxial filter trap 120. As similarly shown
with respect to the '273 and '236 patents described above, the
filter trap 120 is deployable and expandable as shown in FIGS. 17
through 20.
[0061] In FIG. 17 the filter trap is in its initial stage of
deployment. In FIG. 18 the filter trap has been fully expanded.
Additionally, in FIG. 18 there is shown the filter trap 120 used in
combination with the occluding mechanism 116. Using a combination
of these devices provides the invention with the ability to trap
particulate matter 106, whether it flowed against or with the
arrows 108. It will be readily appreciated that any particulate
matter traveling in the direction opposite of the arrows would be
trapped within the filter trap 120. The filter trap 120 is made of
polymeric mesh and can be expanded to a variety of shapes and
sizes. The device 10 includes activation mechanism (not shown)
which can readily expand or contract the filter trap 120.
[0062] It will be appreciated that the inflatable coaxial structure
described with respect to the '273 and '236 patents can, in fact,
define a filter such as the ones described above. It will also be
appreciated that a combination of the inventions taught by the '236
and '273 patents and the disclosure herein can be combined. In
fact, an occluding element could be distal to the distal end of the
catheter 12 with a filter being in-line in an aspiration device. In
this way, the particulate matter is prevented from flowing down
stream by the occlusion mechanism while the aspiration device is
activated causing the particulate matter to be drawn back into the
inflatable coaxial filters. Thus, the fluid down stream of the
occluding mechanism would be relatively free of particulate matter
while the particulate matter would be substantially trapped within
the coaxial filter.
[0063] Upon activation of the motion catheter, a spinning vortex is
created. Upon the direction of the user, the particulate matter 106
can be directed, either proximally or distally, to be trapped by
the filter system described above. Again, the object of trapping
particulate matter is accomplished. In this way, the spinning
vortex causes additional and further particulate matter to be
trapped in a coaxial filter.
[0064] Additionally, polymeric shapes such as a frusto-conical
shape filter trap alternative embodiment generally indicated by the
numeral 122, may alternatively be employed. The filter trap 122,
shown in cross section FIG. 19, includes an outer member 124 and an
inner member 126. Both filter members are connected at their distal
regions 131 and 134 to the distal region 130 of a shaft 128 which
shaft is housed in hollow tube 129. The proximal regions 132 and
133 of filter trap members 124 and 126 are attached to distal
regions 135 and 136 of tube 129. Upon activation both inner and
outer filter members, 124 and 126, respectively, are deployed or
expanded within the blood vessel. Upon deactivation, both filter
members are contracted and fit snugly along shaft 128. The dual
filter has the purpose of (1) sealing against the vessel wall, (2)
capturing large and small particles and the prevention of
dissemination of such fragments, (3) the centering of the catheter
during motion, (4) capturing and holding particulate matter for
dissolution, and (5) capturing of particulate matter allowing blood
or smaller particles to flow through, whereby, at the end of the
procedure, the filter trap is un-deployed and particulate matter is
removed.
[0065] The filter shaft system, upon trapping the particulate
matter 106, can either remain deployed until the blood flow causes
the particulate matter 106 to be dissolved or can be contracted and
then removing the device 10 from the blood vessel and then removing
the trapped particulate matter 106 will thus remove the particular
matter from the blood system.
[0066] The aforesaid specification taken in connection with the
drawings and the aforementioned experiment sets forth the preferred
embodiments of the present invention. The embodiments of the
invention disclosed herein are the best modes contemplated by the
inventors for carrying out their invention in a commercial
environment, although it should be understood that various
modification can be accomplished within the scope of the
invention.
* * * * *