U.S. patent application number 10/160553 was filed with the patent office on 2003-01-23 for integral vascular filter system with core wire activation.
Invention is credited to Johnson, Kirk, Roth, Noah M., Wiatrowski, Tom, Wilson, David.
Application Number | 20030018354 10/160553 |
Document ID | / |
Family ID | 25424762 |
Filed Date | 2003-01-23 |
United States Patent
Application |
20030018354 |
Kind Code |
A1 |
Roth, Noah M. ; et
al. |
January 23, 2003 |
Integral vascular filter system with core wire activation
Abstract
A integral vascular filter system comprising a multi-filament
guidewire and an integral filter which may be used to capture
embolic particulates during medical procedures, while allowing for
continuous perfusion of blood. Filter activation is achieved via
the use of a central core wire. The vascular filter system
addresses the clinical problem of minimizing profile or diameter,
so as to enable or facilitate the crossing of a lesion or
obstruction in the vessel.
Inventors: |
Roth, Noah M.; (Highland
Park, NJ) ; Johnson, Kirk; (Weston, FL) ;
Wilson, David; (Branchburg, NJ) ; Wiatrowski,
Tom; (Levittown, PA) |
Correspondence
Address: |
AUDLEY A. CIAMPORCERO JR.
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
25424762 |
Appl. No.: |
10/160553 |
Filed: |
May 31, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10160553 |
May 31, 2002 |
|
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|
09907860 |
Jul 18, 2001 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2230/008 20130101;
A61M 25/09 20130101; A61F 2230/0006 20130101; A61M 2025/09191
20130101; A61M 2025/09183 20130101; A61F 2002/016 20130101; A61F
2/01 20130101; A61F 2230/0093 20130101; A61F 2002/018 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
That which is claimed is:
1. A vascular filter system for insertion into a lumen of a vessel,
said vascular filter system comprising: a) a multi-filament
guidewire having an outer diameter and an inner diameter, a distal
end and a proximal end, a distal portion and a proximal portion; b)
a prescribed filter shape in said distal portion of said guidewire,
said prescribed filter shape comprising said multi-filaments of
said distal portion of said guidewire; said prescribed filter shape
having a proximal end, a midpoint and a distal end, a smaller first
diameter for insertion into said lumen of said vessel, and a larger
second diameter for expanding to substantially equal the diameter
of said lumen and to be placed in generally sealing relationship
with said lumen; c) a porous covering having a distal end and a
proximal end, with said distal end of said porous covering attached
near said distal end of said prescribed filter shape, and said
proximal end of said porous covering attached near said midpoint of
said prescribed filter shape, and; d) a generally solid actuating
core wire for causing said prescribed filter shape to move between
said smaller first diameter, and said larger second diameter, said
core wire having a proximal end and a distal end, wherein said
distal end of said prescribed filter shape is attached near said
distal end of said core wire, and said guidewire is coaxially
disposed around said core wire.
2. The vascular filter system according to claim 1, wherein said
guidewire is made from Nickel-titanium alloy.
3. The vascular filter system according to claim 1, wherein said
guidewire is made from stainless steel alloy.
4. The vascular filter system according to claim 1, wherein said
prescribed filter shape achieves said smaller first diameter when
said core wire is pushed distally to prevent said multi-filament
wires from achieving said prescribed filter shape, and wherein said
prescribed filter shape achieves said second larger diameter when
said core wire is pulled proximally to allow said multi-filament
wires to achieve said prescribed filter shape.
5. The vascular filter system according to claim 1, wherein said
guidewire is a twisted multi-filament guidewire.
6. The vascular filter system according to claim 1, wherein a pore
size of said porous covering is from about 20 to about 300
microns.
7. The vascular filter system according to claim 1, wherein said
porous covering comprises regularly-spaced laser-formed pores.
8. The vascular filter system, according to claim 1, wherein said
porous covering is a flexible polymeric material.
9. The vascular filter system according to claim 8, wherein said
flexible polymeric material is chosen from a group consisting of
polyurethane, polyethylene, silicone, nylon, polypropylene, PVC, or
a co-polymer or mixture thereof.
10. The vascular filter system according to claim 8, wherein said
flexible polymeric material is an elastomeric material capable of
stretching to achieve said larger second diameter of said
filter.
11. The vascular filter system according to claim 1, wherein said
porous covering is a flexible metallic material.
12. The vascular filter system according to claim 11, wherein said
flexible metallic material is a thin film Nickel Titanium
material.
13. A method for capturing embolic particulates within the lumen of
a vessel during a medical procedure, while allowing for continuous
perfusion of blood, comprising the steps of: a) providing a
multi-filament guidewire having an outer diameter and an inner
diameter, a distal portion and a proximal portion, with a
prescribed filter shape in said distal portion of said guidewire;
said prescribed filter shape comprising said multi-filaments of
said distal portion of said guidewire, said prescribed filter shape
having a proximal end, a midpoint and a distal end, a smaller first
diameter for insertion into a vessel, and a second larger diameter
for expanding to substantially equal the diameter of said lumen and
to be placed in generally sealing relationship with said lumen; a
porous covering having a distal end and a proximal end, with said
distal end of said porous covering attached near said distal end of
said prescribed filter shape, and said proximal end of said porous
covering attached near said midpoint of said prescribed filter
shape; and a generally solid actuating core wire for causing said
prescribed filter shape to move between said smaller first
diameter, and said larger second diameter; said core wire having a
proximal end and a distal end, wherein said distal end of said
prescribed filter shape is attached near said distal end of said
core wire, and said guidewire is coaxially disposed around said
core wire; b) inserting said guidewire into said lumen of said
vessel until said distal portion of said guidewire is positioned
past an occlusion in said vessel; c) retracting said actuating core
wire to cause said distal portion of said guidewire to achieve said
larger second diameter and said prescribed shape; d) advancing
additional devices over said guidewire, and positioning said
devices at the site of said occlusion in said vessel; e) performing
additional procedures to therapeutically treat said occlusion in
said vessel; f) capturing embolic particulates generated by said
procedures, in said porous covering on said distal portion of said
guidewire; g) removing said additional devices from said guidewire;
h) advancing said actuating core wire to cause said distal portion
of said guidewire to achieve said smaller first diameter; and i)
removing said guidewire from said lumen of said vessel, with said
embolic particulates captured in said porous covering.
14. For use with a guidewire-based vascular filter system, the
improvement comprising: a core wire coaxially disposed within said
guidewire, wherein said core wire is placed in tension to deploy
said vascular filter.
15. A vascular filter system for insertion into a lumen of a
vessel, said vascular filter system comprising: (a) a
multi-filament guidewire having an outer diameter and an inner
diameter, a distal end and a proximal end; (b) a prescribed filter
shape near said distal end of said guidewire, said prescribed
filter shape comprising said multi-filaments of said guidewire;
said prescribed filter shape having a proximal end, and a distal
end, a smaller first diameter for insertion into said lumen of said
vessel, and a larger second diameter for expanding to substantially
equal the diameter of said lumen and to be placed in generally
sealing relationship with said lumen; (c) a porous covering
attached near said distal end of said prescribed filter shape, and;
(d) a generally solid actuating core wire for causing said
prescribed filter shape to move between said smaller first
diameter, and said larger second diameter, wherein said guidewire
is coaxially disposed around said core wire.
16. The vascular filter system according to claim 15, wherein said
guidewire is made from Nickel-titanium alloy.
17. The vascular filter system according to claim 15, wherein said
guidewire is made from stainless steel alloy.
18. The vascular filter system according to claim 15 wherein said
prescribed filter shape achieves said smaller first diameter when
said core wire is pushed distally to prevent said multi-filament
wires from achieving said prescribed filter shape, and wherein said
prescribed filter shape achieves said second larger diameter when
said core wire is pulled proximally to allow said multi-filament
wires to achieve said prescribed filter shape.
19. The vascular filter system according to claim 15, wherein said
guidewire is a twisted multi-filament guidewire.
20. The vascular filter system according to claim 15, wherein a
pore size of said porous covering is from about 20 to about 300
microns.
21. The vascular filter system according to claim 15, wherein said
porous covering comprises regularly-spaced laser-formed pores.
22. The vascular filter system, according to claim 15, wherein said
porous covering is a flexible polymeric material.
23. The vascular filter system according to claim 22, wherein said
flexible polymeric material is chosen from a group consisting of
polyurethane, polyethylene, silicone, nylon, polypropylene, PVC, or
a co-polymer or mixture thereof.
24. The vascular filter system according to claim 22, wherein said
flexible polymeric material is an elastomeric material capable of
stretching to achieve said larger second diameter of said
filter.
25. The vascular filter system according to claim 15, wherein said
porous covering is a flexible metallic material.
26. The vascular filter system according to claim 25, wherein said
flexible metallic material is a thin film Nickel Titanium material.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part application of
Applicant's co-pending application, Ser. No. 09/907860, filed Jul.
18, 2001, entitled Integral Vascular Filter System.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the treatment of vascular
disease, and more particularly to an integral vascular filter
system for use during medical procedures.
[0004] 2. Discussion of Related Art
[0005] Percutaneous transluminal coronary angioplasty (PTCA),
stenting and atherectomy are therapeutic medical procedures used to
increase blood flow through the coronary arteries. These procedures
may often be performed as alternatives to coronary bypass surgery.
PTA (percutaneous transluminal angioplasty) and stenting may often
be performed as alternatives to carotid endarterectomy, and
femoral-popliteal bypass procedures. PTRA (percutaneous
transluminal renal angioplasty) and stenting are procedures used to
increase blood flow through the renal arteries, to address problems
with renal function, and hypertension. In PTCA, PTA or PTRA
procedures, the angioplasty balloon is inflated within the stenosed
vessel, at the location of an occlusion, in order to shear and
disrupt the wall components of the vessel to obtain an enlarged
lumen. In stenting, an endoluminal prosthesis is implanted in the
vessel to maintain patency following the procedure. In atherectomy,
a rotating blade is used to shear plaque from the arterial
wall.
[0006] One of the complications associated with all these
techniques is the accidental dislodgment of plaque, thrombus or
other embolic particulates generated during manipulation of the
vessel, thereby causing occlusion of the narrower vessels
downstream and ischemia or infarct of the organ which the vessel
supplies. Such emboli may be extremely dangerous to the patient,
and may result in myocardial infarction, stroke or limb ischemia.
In 1995, Waksman et al. disclosed that distal embolization is
common after directional atherectomy in coronary arteries and
saphenous vein grafts. See Waksman et al., American Heart Journal
129(3): 430-5 (1995). This study found that distal embolization
occurs in 28% (31 out of 111) of the patients undergoing
atherectomy. In Jan. 1999, Jordan, Jr. et al. disclosed that
treatment of carotid stenosis using percutaneous angioplasty with
stenting procedure is associated with more than eight times the
rate of microemboli seen using carotid endarterectomy. See Jordan,
Jr. et al. Cardiovascular Surgery 7(1): 338 (1999). Microemboli, as
detected by transcranial Doppler monitoring in this study, have
been shown to be a potential cause of stroke. The embolic materials
include calcium, intimal debris, atheromatous plaque, and
thrombi.
[0007] In order to initiate these procedures, one must first
introduce a guidewire into the lumen of the vessel to serve as a
conduit for other interventional devices, such as angioplasty
balloons and stent delivery systems. This guidewire must be
advanced into position past the location of the occlusion.
Guidewires must be capable of traversing tortuous pathways within
the body, consisting of bends, loops and branches. For this reason,
guidewires need to be flexible, but they should also be
sufficiently stiff to serve as a conduit for other devices. In
addition, they must be "torqueable" to facilitate directional
changes as they are guided into position. Guidewires are well known
in the art, and are typically made of stainless steel, tantalum or
other suitable materials, in a variety of different designs. See,
for example, U.S. Pat. Nos. 4,545,390,4,619,274, 5,095,915 and
6,191,365.
[0008] Vascular filters are also well known in the art, especially
vena cava filters, as illustrated in U.S. Pat. Nos. 4,727,873 and
4,688,553. Vascular filters are often used during a postoperative
period, when there is a perceived risk of a patient encountering
pulmonary embolism resulting from clots generated peri-operatively.
Pulmonary embolism is a serious and potentially fatal condition
that occurs when these clots travel to the lungs. The filter is
therefore typically placed in the vena cava to catch and trap clots
before they can reach the lungs.
[0009] Many of the vascular filters in the prior art are intended
to be permanently placed in the venous system of the patient, so
that even after the need for the filter has passed, the filter
remains in place for the life of the patient. U.S. Pat. No.
3,952,747 describes a stainless steel filtering device that is
permanently implanted transvenously within the inferior vena cava.
This device is intended to treat recurrent pulmonary embolism.
Permanent implantation is often deemed medically undesirable, but
it is done because filters are implanted in patients in response to
potentially life-threatening situations.
[0010] To avoid permanent implantation, it is highly desirable to
provide an apparatus and method for preventing embolization
associated with angioplasty, stenting or other procedures. In
particular, it is desirable to provide a device which may be
temporarily placed within the vascular system to collect and
retrieve plaque, thrombus and other embolic particulates which have
been dislodged and/or developed as a result of angioplasty,
stenting or other procedures. Such a device is removed at the end
of the procedure. See, for example, U.S. Pat. Nos. 5,814,064,
5,827,324, 5,910,154,. 6,053,932, 6,179,861 and 6,001,118.
[0011] One concern commonly encountered with all these devices is
that the profile or outer diameter of the wire incorporating the
filter tends to be substantially larger than the wire itself. In
addition, many of the prior art devices require the use of a
constraining sheath over the guidewire / filter assembly, which
also increases the overall profile of the device. This larger
profile may make it difficult to cross the lesion or obstruction in
the vessel. If the guidewire with filter cannot cross the lesion or
obstruction, the procedure must be done without a filter in place.
This may lead to accidental dislodgment of plaque, thrombus or
other embolic particulates generated during manipulation of the
vessel, thereby causing occlusion of the narrower vessels
downstream and ischemia or infarct of the organ which the vessel
supplies. Such emboli may be extremely dangerous to the patient,
and may result in myocardial infarction, stroke or limb
ischemia.
[0012] The prior art makes reference to the use of alloys such as
Nitinol (Ni--Ti alloy), which have shape memory and/or superelastic
characteristics, in medical devices that are designed to be
inserted into a patient's body. The shape memory characteristics
allow the devices to be deformed to facilitate their insertion into
a body lumen or cavity, and then, when heated within the body, to
return to their original shape. Superelastic characteristics, on
the other hand, generally allow the metal to be deformed and
restrained in the deformed condition to facilitate the insertion of
the medical device containing the metal into a patient's body, with
such deformation causing the phase transformation. Once within the
body lumen, the restraint on the superelastic member may be
removed, thereby reducing the stress therein so that the
superelastic member may return to its original un-deformed shape by
the transformation back to the original phase.
[0013] The prior art makes reference to the use of metal alloys
having superelastic characteristics in medical devices which are
intended to be inserted or otherwise used within a patient's body.
See for example, U.S. Pat. No. 4,665,905. Some guidewire designs
have recommended the use of superelastic alloys, for example, U.S.
Pat. Nos. 4,925,445 and 4,984,581.
[0014] However, the prior art has yet to disclose any guidewires,
made from Nitinol or other suitable materials, incorporating
vascular filters, which may be used to address the clinical problem
of minimizing profile or diameter, so as to facilitate the crossing
of a lesion or obstruction in the vessel.
SUMMARY OF THE INVENTION
[0015] The present invention provides for an integral vascular
filter system, which may be used to address the clinical problem of
minimizing profile or diameter to enable or facilitate the crossing
of a lesion or obstruction in the vessel, and which overcomes many
of the deficiencies associated with the prior art devices, as
briefly described above.
[0016] In accordance with one aspect, the present invention is
directed to an integral vascular filter system comprising a
multi-filament guidewire, a prescribed filter shape in the distal
portion of the guidewire, and a porous covering attached to the
prescribed filter shape in the distal portion of the guidewire. The
prescribed filter shape may be formed from the multi-filaments of
the distal portion of the guidewire. The distal portion of the
guidewire has a smaller first diameter for insertion into a vessel,
and a second larger diameter for expanding to substantially equal
the diameter of the lumen of the vessel, and to be placed in
generally sealing relationship with the lumen. The system further
comprises an actuating core wire for causing the distal portion of
the guidewire to move between the smaller first diameter, and the
larger second diameter and prescribed filter shape.
[0017] In accordance with another aspect, the present invention is
directed to an integral vascular filter system comprising a
monofilament guidewire, a prescribed filter shape in the distal
portion of the guidewire, and a porous covering attached to the
prescribed filter shape in the distal portion of the guidewire. The
prescribed filter shape may be formed from slots cut into the
distal portion of the guidewire. The distal portion of the
guidewire has a smaller first diameter for insertion into a vessel,
and a second larger diameter for expanding to substantially equal
the diameter of the lumen of the vessel, and to be placed in
generally sealing relationship with the lumen. The system further
comprises an actuating core wire for causing the distal portion of
the guidewire to move between the smaller first diameter, and the
larger second diameter and prescribed filter shape.
[0018] The integral vascular filter system enables or facilitates
crossing lesions or obstructions in vessels by minimizing the
profile or diameter of the overall system, due to the integral
nature of the filter, and due to the elimination of the need for a
constraining sheath over the guidewire/filter assembly. The filter
is actuated through the use of a core wire, and is then used to
capture embolic particulates released during a medical procedure.
The filter is then collapsed, and the system is removed from the
patient.
[0019] The advantage of the present invention is that the low
profile or minimized diameter of the integral vascular filter
system may enable or facilitate the crossing of lesions or
obstructions in the vessel, which may not be crossable with other
filter devices.
BRIEF DESCRIPTION OF DRAWINGS
[0020] The foregoing and other aspects of the present invention
will best be appreciated with reference to the detailed description
of the invention in conjunction with the accompanying drawings,
wherein:
[0021] FIG. 1 is an simplified, cross-sectional view of an
exemplary embodiment of the integral vascular filter system made
from multi-filament wire, with the filter in the open position, in
accordance with the present invention.
[0022] FIG. 2 is an enlarged, partial cross-sectional view of an
exemplary embodiment of the integral vascular filter system made
from multi-filament wire, in accordance with the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The integral vascular filter system of the present invention
is designed to address the clinical problem of minimizing profile
or diameter to enable or facilitate the crossing of a lesion or
obstruction in the vessel. The device comprises a multi-filament
guidewire having an outer diameter and an inner diameter, a distal
end and a proximal end, a distal portion and a proximal portion,
and a prescribed filter shape in the distal portion of the
guidewire, the distal portion having a proximal end, a midpoint and
a distal end, a smaller first diameter for insertion into the lumen
of a vessel, and a larger second diameter for expanding to
substantially equal the diameter of the lumen and to be placed in
generally sealing relationship with the lumen; a porous covering
having a distal end and a proximal end, with the distal end of the
porous covering attached near the distal end of the prescribed
filter shape, and the proximal end of the porous covering attached
near the midpoint of the proximal filter shape; and an actuating
core wire for causing the distal portion of the guidewire to move
between the smaller first diameter and the larger second diameter
and the prescribed filter shape. The integral vascular filter may
be of sufficiently small profile or diameter to cross the lesion or
occlusion, and may be placed distal to the occlusion to collect
embolic particulates released during the procedure. Thereafter, the
filter may be closed and removed from the patient, with the embolic
particulates trapped within the filter.
[0024] While the present invention may be realized in a number of
exemplary embodiments, for ease of explanation, one exemplary
embodiment will be described in detail. Referring to the figures
wherein like numerals indicate the same element throughout the
views, there is shown in FIG. 1, an integral vascular filter system
10 made in accordance with the present invention. The integral
vascular filter system 10 comprises a guidewire 12, which comprises
a guidewire distal portion 14 with a prescribed filter shape. The
guidewire distal portion 14 comprises a porous covering 16 attached
to the guidewire distal portion 14. The guidewire is coaxially
disposed around an actuating core wire 13. As illustrated in FIG.
1, when the guidewire distal portion 14 achieves its larger second
diameter and prescribed filter shape, the filter is in the open
position. As illustrated in FIG. 2, when the guidewire distal
portion 14 achieves its smaller first diameter, the filter is in
the closed position.
[0025] In accordance with an exemplary embodiment, as illustrated
in FIGS. 1 and 2, the guidewire 12 may be a multi-filament wire. As
illustrated in FIG. 1, the guidewire distal portion 14 has a
prescribed filter shape formed from the filaments 24 of the
multi-filament wire. The guidewire distal portion 14 comprises a
porous covering 16 attached to the guidewire distal portion 14. As
illustrated in FIG. 1, when the guidewire distal portion 14
achieves its larger second diameter and prescribed filter shape,
the filter is in the open position.
[0026] As illustrated in FIGS. 1, and 2, the integral vascular
filter system 10 may be used to cross lesions or obstructions in a
vessel, and may then be used to collect and trap embolic
particulates released during a medical procedure. The guidewire 12
is introduced into the lumen of the vessel, with the distal portion
14 in the closed position. The actuating core wire 13 may be used
to prevent actuation of the filter by advancing it distally, while
the integral vascular filter system 10 is being positioned in the
vessel, with the guidewire distal portion 14 positioned past the
lesion or occlusion. Other actuating means, such as guide catheters
or other procedural devices may also be employed. Once the integral
vascular filter system 10 is in position past the lesion or
occlusion, the core wire 13 may be retracted to allow the guidewire
distal portion 14 to achieve its larger second diameter and
prescribed shape, with the porous covering 16 attached to the
guidewire distal portion 14. At this point, other procedural
devices, such as angioplasty balloons and stent delivery systems,
may be introduced over the guidewire 12, to therapeutically treat
the lesion or occlusion. Any embolic particulates released during
the procedure may be captured in the porous covering 16 on the
guidewire distal portion 14, while the pores in the porous covering
allow distal perfusion of blood. When the therapeutic treatment of
the lesion or occlusion is complete, the procedural devices may be
withdrawn, and the core wire 13 may be advanced to return the
guidewire distal portion 14 to its smaller first diameter. The
guidewire 12 may then be removed from the lumen of the vessel.
[0027] The guidewire 12 may be made from any number of suitable
materials, and is preferably made from stainless steel, and is more
preferably made from a superelastic alloy such as Nitinol. The
guidewire 12 may be a multi-filament wire, and may comprise
straight or, more preferably, twisted multi-filaments. The
guidewire may alternatively be a monofilament guidewire, and the
guidewire distal portion 14 may alternatively comprise any number
or configuration of slots, and may preferably comprise longitudinal
slots. The actuating core wire may be made from any number of
suitable materials, and is preferably made from stainless steel or
Nitinol. The Nitinol actuating core wire may further comprise a
prescribed filter shape of its own formed by slots cut into the
distal portion of the core wire. The porous covering 16 may be made
from any number of suitable materials, and is preferably made from
a flexible polymeric material with elastomeric properties chosen
from a group consisting of polyurethane, polyethylene, silicone,
nylon, polypropylene, PVC, or a co-polymer or mixture thereof. The
porous covering 16 may also be made from a flexible metallic
material, and is preferably made from a thin film Nickel Titanium
material with superelastic and shape memory characteristics. The
porous covering 16 may comprise any number and configuration of
pores and may preferably comprises regularly-spacer laser-formed
holes wherein the pore size is from about 20 to about 300
microns.
[0028] Although shown and described are what are believed to be the
preferred embodiments, it is apparent that departures from specific
designs and methods described and shown will suggest themselves to
those skilled in the art and may be used without departing from the
spirit and scope of the invention. The present invention is not
restricted to the particular constructions described and
illustrated, but should be constructed to include all modifications
that may fall within the scope of the appended claims. strange
indentions in claims
* * * * *