U.S. patent application number 10/096624 was filed with the patent office on 2003-09-18 for everted filter device.
Invention is credited to Anderson, Kent, Berrada, Marwane, Kusleika, Richard.
Application Number | 20030176884 10/096624 |
Document ID | / |
Family ID | 28039044 |
Filed Date | 2003-09-18 |
United States Patent
Application |
20030176884 |
Kind Code |
A1 |
Berrada, Marwane ; et
al. |
September 18, 2003 |
Everted filter device
Abstract
Everting filter devices and methods for using the devices,
including using the devices as intra-vascular filters to filter
thrombus, emboli, and plaque fragments from blood vessels. The
filter devices include a filter body nominally tubular in shape and
having a large proximal opening. The filter body can extend from a
proximal first end region distally over the non-everted exterior
surface of the filter, further extending distally to a distal-most
region, then converging inwardly and extending proximally toward
the filter second end region, forming a distal everted cavity. The
degree of eversion of the filter can be controlled by varying the
distance between the filler first end region near the proximal
opening and the closed second end region. Bringing the filter first
and second end regions closer together can bring filter material
previously on the non-everted filter exterior to occupy the
distal-most region. The everting process can also bring filter
material previously in the distal-most position further into the
distal everted cavity. The filter devices can be used to remove
filtrate from body vessels, with the filtrate eventually occluding
the distal-most region. The filter can then be further everted,
bringing fresh, unoccluded filter material into place to provide
additional filter capacity. Some everting filters have the
capability of switching between occluding and filtering modes of
operation, thereby allowing a treating physician to postpone the
decision to use filtering or occluding devices until well after
insertion of the device into the patient's body.
Inventors: |
Berrada, Marwane; (White
Bear Lake, MN) ; Kusleika, Richard; (Eden Prairie,
MN) ; Anderson, Kent; (Champlin, MN) |
Correspondence
Address: |
Craig F. Taylor
Fredrikson & Byron, P.A
900 Second Avenue South
1100 International Centre
Minneapolis
MN
55402
US
|
Family ID: |
28039044 |
Appl. No.: |
10/096624 |
Filed: |
March 12, 2002 |
Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2230/0069 20130101;
A61F 2/0105 20200501; A61F 2002/018 20130101; A61F 2230/008
20130101; A61F 2230/0006 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A filter device for filtering a body vessel fluid in a patient's
body, the vessel having interior walls, the filter device
comprising: a filter body having an open proximal end region and a
closed, everted distal end region, the filter body being formed of
a porous mesh, the mesh defining a filter body interior and
exterior, wherein the everted distal end region has an exterior
distal everted cavity; a first elongate member having a distal
region operably coupled to the filter body distal end region; and
means for changing the degree of eversion of the filter body by
changing the distance between the filter body proximal and distal
end regions.
2. A filter device as in claim 1, wherein the means for changing
the degree of eversion includes the filter body being biased to
expand radially outward against the vessel interior walls to hold
the filter body in place, wherein the means for changing the degree
of eversion also includes means for moving the first elongate
member and coupled filter body distal end region.
3. A filter device as in claim 2, wherein the first elongate member
is a tether and the means for moving the first elongate member
includes the first elongate member having a proximal region
accessible from outside the patient's body.
4. A filter device as in claim 2, wherein the first elongate member
is a shaft and the means for moving the first elongate member
includes the first elongate member having a proximal region
accessible from outside the patient's body.
5. A filter device as in claim 1, further comprising a second
elongate member operably coupled to the filter body proximal end
region, wherein the means for changing the degree of eversion also
includes means for moving the first and second elongate
members.
6. A filter device as in claim 5, wherein the second elongate
member is a shaft and the means for moving the first and second
elongate members includes the first and second elongate members
each having a proximal region accessible from outside the patient's
body.
7. A filter device as in claim 5, wherein the first and second
elongate members are shafts and the means for moving the first and
second elongate members includes the first and second elongate
members each having a proximal region accessible from outside the
patient's body.
8. A filter device as in claim 5, wherein the second elongate
member is a shaft having a lumen therethrough having the first
elongate member slidably disposed within, and the means for moving
the first and second elongate members includes the first and second
elongate members each having a proximal region accessible from
outside the patient's body.
9. A filter device as in claim 5, wherein the second elongate
member is a tether having a distal region operably coupled to the
filter body proximal end region, wherein the first elongate member
is a shaft having a lumen therethrough having the second elongate
member slidably disposed within, and the means for moving the first
and second elongate members includes the first and second elongate
members each having a proximal region accessible from outside the
patient's body.
10. A filter device as in claim 1, wherein the porous mesh is
self-expanding.
11. An everted filter device comprising: an elongate member having
a proximal portion and a distal portion, the distal portion having
a proximal region a distal region, and an outer surface; and a mesh
filter body having an average pore size, the filter body having a
first end region slidably secured to the elongate member distal
portion proximal region, a filter body second end region opposite
the first end region fixedly secured to the elongate member distal
portion distal region, a filter body intermediate region disposed
between the filter body first and second end regions, and at least
one proximal opening having a size at least five times the average
filter body pore size, wherein the filter body has an everted
distal exterior cavity having a length, wherein the filter body
distal cavity length can be varied by varying the distance between
the filter body first and second end regions.
12. A device as in claim 11, wherein the mesh filter body has at
least two proximal openings having a size at least five times the
average pore size.
13. A device as in claim 11, wherein the filter body has an
exterior surface and an interior surface, wherein the filter body
exterior surface is operably coupled to and faces the elongate
member outer surface.
14. A device as in claim 13, wherein the filter body second end
region exterior surface is directly fixed to the elongate member
distal portion distal region outer surface.
15. A device as in claim 13, wherein the filter body second end
region exterior surface is fixed to the elongate member distal
portion distal region with a distal band.
16. A device as in claim 11, wherein the filter body proximal end
region is slidably secured to the elongate member with a proximal
band fixedly secured to the filter body first end region wherein
the proximal band is slidably disposed over the elongate
member.
17. A device as in claim 11, wherein the filter body distal everted
cavity is formed by the filter body second end region interior
surface being secured to and facing the elongate member distal
portion distal region outer surface, such that a distal cavity
proximal most extent is formed by the filter body exterior surface,
wherein the filter body is biased to assume the everted shape when
unconstrained.
18. A device as in claim 17, wherein the filter body second end
region is secured to the elongate member distal portion distal
region with a distal band disposed over the filter body second end
region.
19. A device as in claim 11, further comprising an atraumatic tip
extending distally from the elongate member.
20. A device as in claim 11, wherein the filter body is biased to
expand radially outward to anchor the filter body to an enclosing
vessel wall.
21. A device as in claim 11, wherein the elongate member is a
shaft.
22. A device as in claim 11, wherein the device has a proximal band
slidably disposed over the elongate member, wherein the band has an
inner surface facing the elongate member, an outer surface forming
the band exterior, and an intermediate region between the inner
surface and outer surface, wherein the filter body first end region
is secured within the proximal band intermediate region.
23. A device as in claim 22, wherein the proximal band is formed of
an inner proximal band and outer proximal band, having the filter
body first end region disposed between the inner and outer proximal
bands.
24. A device as in claim 11, wherein the elongate member is a shaft
having a lumen therethrough.
25. A device as in claim 11, wherein the filter body is heat set to
evert when unconstrained.
26. A device as in claim 11, wherein the filter body is
self-expanding.
27. A method for capturing a filtrate material from a fluid in a
body vessel, the method comprising the steps of providing a filter
device including an elongate member having a proximal portion and a
distal portion, the distal portion having a proximal region, and a
distal region, the filter device further including a mesh filter
body formed of a filter material having an average pore size, the
filter body having a first end region slidably secured to the
elongate member distal portion proximal region, a filter body
second end region opposite the first end region fixedly secured to
the elongate member distal portion distal region, a filter body
intermediate region disposed between the filter body first and
second end regions, the filter body extending distally from the
proximal opening and everting over a distal-most region to converge
radially inwardly and proximally to form an exterior distal everted
cavity, and at least one proximal opening having a size at least
five times the average filter body pore size; advancing the filter
body to a vessel region to be filtered; deploying the filter device
in a first configuration where the filter body has a first
collection region of filter material occupying the distal-most
region; and collecting the filtrate in the filter body first
collection region.
28. A method as in claim 27, further comprising relocating the
first collection region from the distal-most region to a more
proximal region and moving a second collection region to occupy the
distal-most region by changing the degree of eversion of the filter
body by varying the distance between the filter body first and
second regions.
29. A method as in claim 28, wherein the relocating step includes
increasing the distance between the filter body first and second
regions to bring filter material from the distal cavity to occupy
the distal-most region and to bring the first collection region
radially outside of and proximal of the distal cavity.
30. A method as in claim 29, wherein the increasing distance step
includes distally advancing the filter body second end region.
31. A method as in claim 29, wherein the method includes providing
the filter body biased to expand radially against the vessel wall
to anchor the filter body, wherein the increasing distance step
includes distally advancing the filter body second end region
relative to the anchored filter body first end region.
32. A method as in claim 28, wherein the relocating step includes
decreasing the distance between the filter body first and second
regions to bring filter material from proximal of and radially
outside the distal-most region to occupy the distal-most region and
to bring the first collection region into the distal cavity.
33. A method as in claim 32, wherein the decreasing distance step
includes proximally retracting the elongate member.
34. A method as in claim 32, wherein the decreasing distance step
includes proximally retracting the filter body second end
region.
35. A method as in claim 32, wherein the method includes providing
the filter body biased to expand radially against the vessel wall
to anchor the filter body, wherein the decreasing distance step
includes proximally retracting the filter body second end region
relative to the anchored filter body first end region.
36. An everted filter device comprising: a first shaft having a
proximal portion and a distal portion, the distal portion having a
distal region; a second shaft having a proximal portion, a distal
portion, the distal portion having a distal region and a proximal
region; and a filter body formed of a porous mesh material having
an average pore size, a first end region secured to the first shaft
distal portion distal region, the filter body having a second end
region secured to the second shaft distal portion distal region,
the filter body having at least one proximal opening having an
opening size at least five times the filter body average pore size,
wherein the filter body distal region is everted when unconstrained
to form an exterior distal everted cavity.
37. A device as in claim 36, wherein the second shaft is slidably
coupled to the first shaft.
38. A device as in claim 37, wherein the first shaft has a lumen
therethrough having the second shaft slidably disposed within.
39. A device as in claim 37, wherein the second shaft includes a
curved region disposed distally of the first and second shaft
slidable coupling and biased to assume a curved shape when
unconstrained.
40. A device as in claim 37, wherein the second shaft extends
distally and transversely away from the first shaft slidable
coupling to inhibit proximal movement of the second shaft.
41. A device as in claim 37, wherein the second shaft extends
distally and transversely away from the first shaft coupling to
limit proximal movement of the second shaft.
42. A device as in claim 36, wherein the second shaft is slidably
coupled to the first shaft through a frictional lock giving tactile
indication through the second shaft of translational movement of
the second shaft relative to the first shaft.
43. A device as in claim 36, wherein the second shaft is slidably
coupled to the first shaft through a frictional lock limiting
translational movement of the second shaft relative to the first
shaft.
44. A device as in claim 36, wherein the mouth region includes a
loop secured to at least part of the mouth region, wherein the loop
includes a first portion disposed through the body proximal mouth
region and a second portion disposed between the first shaft and
the filter body proximal mouth region, wherein the loop is slidably
disposed within the filter body proximal mouth region, such that
the body proximal opening may be decreased in size by proximally
retracting the loop relative to the body proximal mouth region.
45. A device as in claim 36, wherein the porous mesh is
self-expanding.
46. An everted filter device comprising: a shaft having a proximal
portion, a distal portion, the distal portion having a distal
region; and a porous mesh filter body having a first end region, a
second end region, and an intermediate region disposed between the
first and second end regions, the body having a proximal opening
having a cross sectional area at least about five times the average
pore cross sectional area of the filter body, wherein the opening
is disposed within a proximal mouth region; wherein the shaft is
coupled to the filter body second end region, and the shaft distal
region is coupled to the filter body proximal mouth region with at
least two elongate fastening members.
47. A device as in claim 46, wherein the fastening members are
struts acting to hold the filter body proximal opening in an open
configuration.
48. A device as in claim 46, wherein the fastening members are
tethers and the filter body is biased to hold the filter body
proximal opening in an open configuration.
49. A device as in claim 46, wherein the filter body is biased
remain in the open position through the biasing action of a
proximal loop secured to the body proximal mouth region.
50. A device as in claim 46, wherein the fastening members are
tethers having distal regions and the shaft has a lumen
therethrough, wherein the tethers are operably coupled at the
distal regions to the body proximal mouth region and extend
proximally into the shaft lumen.
51. A device as in claim 50, wherein the tethers extend through the
lumen to the shaft proximal region such that the tethers are
accessible for manipulation from the shaft proximal region.
52. A device as in claim 46, wherein the porous mesh is
self-expanding.
53. An everted occluding/perfusing device comprising: a first shaft
having a proximal portion and a distal portion, the distal portion
having a distal region; a second shaft having a proximal portion, a
distal portion, the distal portion having a distal region and a
proximal region; and a mesh body having an average pore size, a
first end region secured to the first shaft distal portion distal
region, the mesh body having a second end region secured to the
distal shaft distal portion distal region, the mesh body having at
least one proximal opening having an opening size at least five
times the mesh body average pore size, the mesh body having an
interior and a exterior, wherein the mesh body distal region is
everted when unconstrained to form a distal-most region and
converges inwardly and proximally to form an exterior distal
everted cavity, wherein the mesh body has a perfusing portion and
an occluding portion disposed over the mesh body such that changing
the degree of eversion of the mesh body changes the device between
the occluding and perfusing portions being disposed in the
distal-most region of the mesh body.
54. A device as in claim 53, wherein the occluding portion is
disposed near the mesh body second end, wherein the perfusing
portion is disposed between the occluding portion and the mesh body
first end region, such that moving the mesh body second end region
toward the body first end region acts to further evert the mesh
body and cause the occluding region to form the distal cavity wall
while causing the perfusing portion to occupy the distal-most
region of the occluding/perfusing device.
55. A device as in claim 53, wherein the perfusing portion is
disposed nearer the body second end region and the occluding
portion is disposed between the perfusing portion and the body
first end region, such that moving the body second end region
toward the body first end region acts to further evert the mesh
body and cause the perfusing portion to form the distal cavity wall
while causing the occluding portion to occupy the distal-most
region of the occluding/perfusing device.
56. A device as in claim 53, wherein the mesh body perfusing
portion is formed of filter material, the filter material having an
average pore size of less than about 500 microns.
57. A device as in claim 54, further comprising a distal fluid port
disposed in the first shaft for allowing fluid infusion through the
port and into the mesh body interior.
58. A device as in claim 54, further comprising a fluid infusion
lumen disposed along the first shaft and is in fluid communication
with a distal fluid port for allowing fluid infusion through the
port and into the mesh body interior.
59. A device as in claim 58, wherein the fluid infusion lumen is
disposed within the first shaft.
60. A method for filtering filtrate material from a body vessel
fluid, the method comprising the steps of: providing a filter
device including a filter body having a proximal opening disposed
within a proximal mouth region, a closed everted distal region
having a exterior distal everted cavity and a distal-most region,
wherein the filter body has a filtering portion and an occluding
portion oriented so that the filter body can be manipulated between
an occluding mode and a filtering mode by changing the degree of
eversion of the filter body, the filter device further including an
elongate first member having a proximal end region, a proximal
region and a distal region, the elongate first member distal region
being coupled to the filter body closed everted region; advancing
the filtering device filter body to the body vessel region to be
filtered; manipulating the filter body to a first configuration so
that the distal-most region of the filter body is occupied by the
filter body occluding portion to substantially occlude flow of the
vessel fluid; changing the degree of eversion of the filter body so
that the distal-most region of the filtering device is occupied by
the filter body filtering portion to capture the filtrate; and
filtering the body vessel fluid to collect filtrate in the filter
body distal-most region.
61. A method as in claim 60, wherein the filter device further
comprises a second elongate member having a proximal region and a
distal region, wherein the filter body proximal region is coupled
to the second elongate member distal region, wherein the changing
degree of eversion step includes changing the distance between the
first and second elongate member distal regions, to change the
distance between the filter body first and second end regions.
62. A method as in claim 60, wherein the filter body is biased to
expand radially against an enclosing body vessel wall to anchor the
filter body, wherein the changing degree of eversion step includes
changing the distance between the first elongate member distal
region and the filter body proximal mouth region, to change the
distance between the filter body first and second end regions.
63. A method as in claim 62, wherein the changing distance step
includes manipulating the first elongate member from the first
elongate member proximal portion end to urge the elongate member
distal region proximally.
64. A method for delivery an agent to a body vessel interior
region, the method comprising the steps of: providing an infusion
device including a filter body having a proximal opening disposed
within a proximal mouth region, a closed everted distal region
having a distal exterior everted cavity and a distal-most region,
wherein the filter body has a filtering portion and an occluding
portion oriented so that the filter body can be manipulated between
an occluding mode and a filtering mode by changing the degree of
eversion of the filter body, the infusion device further including
an elongate first member having a proximal region and a distal
region, the elongate first member distal region being coupled to
the filter body closed everted region, the infusion device further
including an infusion lumen disposed along the first elongate
member and in fluid communication with a distal port; advancing the
infusion device filter body to the body vessel region to be
treated; manipulating the infusion device to a first configuration
where the filter body has a region of occluding material occupying
the distal-most region to reduce flow through the vessel and
wherein the filter body has a region of filtering material facing
the vessel interior walls to allow agent flow through the filtering
material vessel walls; and infusing the agent through the infusion
lumen into the filter body interior to allow the agent to contact
the vessel walls through the porous material.
65. A method as in claim 64, wherein the infusion lumen is disposed
within the first elongate member and the infusing step includes
infusing the agent through the first elongate member.
66. A method as in claim 65, wherein the infusion device further
comprises a second elongate member having a distal region coupled
to the filter body first end region, wherein the second elongate
member is a tube having the first elongate member slidably disposed
within and wherein the infusion lumen is an annular lumen disposed
within the tube about the first elongate member, wherein the
infusing step includes infusing the agent through the annular
lumen.
67. A filter device comprising: a first shaft having a proximal
portion and a distal portion, the distal portion having a distal
region; a second shaft having a proximal portion and a distal
portion, the distal portion having a distal region and a proximal
region; and a porous filter body having an average pore size, a
first end region secured to the first shaft distal portion distal
region, the filter body having a second end region secured to the
second shaft distal portion distal region, the filter body having
at least one proximal opening having an opening size at least five
times the filter body average pore size, wherein the filter body
distal region is everted when unconstrained to form an exterior
distal everted cavity, wherein at least one of the first or second
shafts has a lumen therethrough in fluid communication with an
inflatable envelope disposed within the filter body, wherein the
inflatable envelope has a distal waist region and a proximal waist
region, wherein the balloon has an inflated configuration for
substantially occluding the filter body interior and a second
configuration substantially less occluding than the first occluding
configuration.
68. A method for occluding and filtering a vessel region, the
method comprising the steps of: providing a filter device
including: a first shaft having a proximal portion and a distal
portion, the distal portion having a distal region; a second shaft
having a proximal portion, a distal portion, the distal portion
having a distal region and a proximal region; and a porous mesh
filter body having an average pore size, a first end region secured
to the first shaft distal portion distal region, the filter body
having a second end region secured to the second shaft distal
portion distal region, the filter body having at least one proximal
opening having an opening size at least five times the filter body
average pore size, wherein the filter body distal region is everted
when unconstrained to form an exterior distal everted cavity,
wherein at least one of the first or second shafts has a lumen
therethrough in fluid communication with an inflatable envelope
disposed within the filter body, wherein the inflatable envelope
has a distal waist region and a proximal waist region, wherein the
balloon has an inflated configuration for substantially occluding
the filter body interior and a second configuration substantially
less occluding than the first occluding configuration; advancing
the filter device to a region to be filtered; inflating the balloon
to substantially occlude the vessel; and uninflating the balloon to
allow greater body fluid passage around the balloon.
69. A method as in claim 68, wherein the occlusion step is
performed after the filtering step.
70. A method for removing blockage material from a vessel, the
method comprising the steps of: providing a filter device
including: a first shaft having a proximal portion and a distal
portion, the distal portion having a distal region, a second shaft
having a proximal portion, a distal portion, the distal portion
having a distal region and a proximal region, and a filter body
having an average pore size, a first end region secured to the
first shaft distal portion distal region, the filter body having a
second end region secured to the second shaft distal portion distal
region, the filter body having at least one proximal opening having
an opening size at least five times the filter body average pore
size, wherein the filter body distal region is everted when
unconstrained to form an exterior distal everted cavity, and a
proximal loop disposed near the filter body proximal mouth region;
deploying the filtering device distally of the blockage material in
a configuration where the proximal loop is in a substantially open
configuration; and proximally retracting the proximal loop over the
blockage material such that the blockage material is at least
partially captured within the filter interior while elongating the
porous mesh filter.
71. A method as in claim 70 further comprising allowing the second
shaft to remain substantially in place while retracting the first
shaft to elongate and increase the length of the filter body during
the blockage material capture method.
72. A method as in claim 70 further comprising providing a capture
tube having a lumen through at least a capture tube distal region,
the method further comprising the step of proximally retracting the
filter body having the blockage material within the capture tube
distal region.
73. A method as in claim 70, wherein the blockage material includes
thrombus and the proximally retracting step includes proximally
retracting the loop over the thrombus.
Description
FIELD OF THE INVENTION
[0001] The present invention is related generally to medical
devices. The present invention includes intravascular filter
devices.
BACKGROUND OF THE INVENTION
[0002] Coronary vessels, partially occluded by plaque, may become
totally occluded by a thrombus or blood clot causing myocardial
infarction, angina and other conditions. A number of medical
procedures have been developed to allow for the removal of plaque
from vessel walls or to clear a channel through the thrombus or
clot to restore blood flow and minimize the risk of myocardial
infarction. Carotid, renal, peripheral, and other blood vessels can
also be blocked and require treatment. For example, atherectomy or
thrombectomy devices can be used to remove atheroma or thrombus.
Alternatively, in percutaneous transluminal coronary angioplasty
(PTCA), a guide wire or guide catheter is inserted into the femoral
artery of a patient near the groin, advanced through the artery,
over the aorta, and into a coronary artery. An inflatable balloon
is then advanced into the coronary artery, across a stenosis or
blockage, and the balloon inflated to dilate the blockage and open
a flow channel through the partially blocked vessel region. While
some stenoses remain in place once dilated, others are more
brittle, and may partially crack and fragment, allowing the
fragments to flow downstream where they may block more distal and
smaller coronary vessels, possibly causing myocardial infarction,
from that site. Consequences of embolization include stroke,
diminished renal function, and impairment of peripheral circulation
possibly leading to pain and amputation.
[0003] Saphenous vein grafts are often used to bypass occluded
coronary vessels in coronary artery bypass surgery. With time, the
grafts can become occluded with grumous. The grumous can also be
dilated with balloons or removed in other ways. The grumous can
present an even more difficult material to remove than thrombus, as
the material is very friable, and likely to break into smaller
fragments during the removal procedure.
[0004] Distal embolic protection devices have been developed to
prevent the downstream travel of materials such as thrombi,
grumous, emboli, and plaque fragments. Devices include occlusive
devices and filters. Occlusive devices, for example distal
inflatable balloon devices, can totally block fluid flow through
the vessel. The material trapped by the inflatable devices can
remain in place until removed using a method such as aspiration.
However, aspiration cannot remove large particles because they
won't fit through the aspiration lumen. Also, aspiration is a weak
acting force and won't remove a particle unless the tip of the
aspirating catheter is very close to the particle to be removed.
During the occlusion, the lack of fluid flow can be deleterious. In
coronary applications, the lack of perfusing blood flow can cause
angina. In carotids, seizure can result from transient blockage of
blood flow. In both coronaries and carotids it is not possible to
predict who will suffer from angina or seizure due to vessel
occlusion. If a procedure is started with an occlusive device, it
may be necessary to remove it and start over with a filter
device.
[0005] Some distal embolic protection devices include filters. The
filters can be advanced downstream of a site to be treated and
expanded to increase the filter area. Filtrate, such as emboli, can
be captured in the filter until the procedure is complete or the
filter is occluded. When the capacity of the filter is reached, the
filter becomes occluded, blocking fluid flow past the filter
device. The filter may then be retracted and replaced or left as
is. If the filter is replaced with a fresh unoccluded filter, extra
wire motions are required along with extra time. While the
replacement is occurring, there is a period of no embolic
protection for the patient and a risk of dislodging emboli during
filter manipulation. If the filter is left in place, the vessel
will be occluded during the remainder of the procedure and the
patient can suffer the consequences of occlusion described earlier.
Both choices are less than optimal.
[0006] Another shortcoming of current filters relates to their use
distal of emboli sources when the emboli sources are located
immediately proximal of a vessel bifurcation or trifurcation.
Multiple filters may be required, one for each vessel branch, which
is cumbersome and may not be done well, if attempted at all.
Further, the use of multiple filters may not be compatible with
other needed equipment such as angioplasty balloons and/or
stents.
[0007] Some physicians prefer to use filters while others prefer to
use occlusive devices. Whether a particular procedure may call for
use of an occlusive device or a filter device may not be known
until midway through the procedure. Occlusive distal protection
devices are generally preferred for use in carotid vessels where
even tiny particles can cause big problems if they happen to lodge
in a very important but small artery. However, occlusive devices
compromise fluoroscopic imaging due to the lack of flow during
radiopaque dye injection.
[0008] What would be desirable are intravascular filters capable of
additional filtering after being occluded with thrombi, without
being removed from the body. What would be advantageous are
intravascular filters which can be manipulated between a filtering
mode and an occluding mode. Filters that can be used in the
vicinity of a bifurcation would be beneficial.
SUMMARY OF THE INVENTION
[0009] The present invention provides everted filter trap devices
and methods for using the everted filters. The devices can be used
in body vessels including the coronary, carotid, renal,
neurological and cerebral blood vessels, as well as ureters, and
the respiratory and biliary tracts. The everted filters can include
a tubular filter body having a large proximal opening and a closed
distal end. The filter body can extend distally from a first end
region near the filter body proximal opening, further extending
over an intermediate, non-everted region, continuing distally and
everting over a distal-most region. The everting causes the filter
body exterior to converge inwardly and proximally to a closed,
filter body second end region. The proximally extending and
inwardly converging exterior surface of the filter body defines a
distal, everted cavity bounded distally by the distal-most extent
of the everting filter. The distal everted cavity has exterior
cavity walls which extend proximally back towards the proximal
opening. The degree of eversion of the filter body may be changed
through controlling the relative positions of the filter body first
and second end regions. When the filter body diameter is held
constant, proximally withdrawing the everted second end region
toward the first end region increases the degree of eversion,
increasing the distal everted cavity volume and length and
increasing the length of filter body exterior surface within the
distal, everted cavity.
[0010] In use, an everting filter device can be advanced to a
target region within a body vessel region to be filtered. Some
everting filter devices can be advanced over a guide wire, while
other devices can be advanced in a constrained state within a
delivery sheath. The everting filter body is preferably biased to
expand radially outward to approach the target region vessel walls.
The everting filter can be initially deployed in a minimally
everted configuration, having a small distal everted cavity volume
and length. With time, the everting filter interior surface near
and around the filter distal-most region may become occluded with
filtrate material. The everting filter may then be further everted,
by bringing the filter body first and second end regions closer
together. This relative movement can bring the occluded body
material previously in the distal-most position to a position
within the distal everted cavity sidewalls. This relative movement
also brings filter material previously on the outside, non-everted
surface region of the filter to the distal-most position, thereby
providing fresh, non-occluded filter material.
[0011] The everting filter can provide fresh, porous, non-occluded
filter material while proximally relocating the occluded filter
material so that the perfusing vessel fluid flow is directed
sideways over the occluded material rather than directly into the
material. When the everting filter capacity is reached or the
filtering is otherwise complete, the filter can be proximally
retracted within a filter capture device, for example, a sheath.
The captured, filtrate containing filter can then be withdrawn from
the patient's body.
[0012] Some everting filter devices have a first, proximal shaft
coupled to the filter body first end region and a second, distal
shaft coupled to the filter body second end region, allowing the
relative and absolute movements of the filter body end regions to
be independently controlled. In some filter bodies, the distal
shaft can be slidably disposed within the proximal shaft. In some
embodiments, the distal shaft has a lumen for passing a guide wire
therethrough. Some everting filter devices have only a single shaft
coupled to the filter body second end region in the distal everted
cavity. Such everting devices can rely on the radially outward
expansion of the filter body against the vessel walls to anchor the
filter body. The relative movement of the single shaft and coupled
everted distal end of the filter body can control the degree of
eversion by moving the single shaft relative to the anchored filter
body.
[0013] Some everting filter devices can operate as
filtering/occluding devices. One group of such devices have a
filter body which includes an occluding portion and a filtering
portion. The device can be operated in filtering mode by bringing
the filtering portion to the distal-most region of the filter. The
occluding mode can be attained by bringing the occluding portion of
the filter body to the distal-most region. Some devices have a
proximal filtering portion followed by a more distal occluding
portion, while other devices have a proximal occluding portion
followed distally by a filtering portion. The degree of eversion
can control whether the filtering portion is disposed about the
outside circumference of the filter body, in the distal-most
region, or within the everting distal cavity to form the side
walls. Such occluding/filtering devices can allow postponing the
decision to use a filtering device or an occluding device past the
time of deploying the device within the patient's vessel.
[0014] Other everting filter devices can be used as thrombectomy
devices. The thrombectomy devices preferably have a large proximal
opening and a proximal hoop or loop disposed near the proximal
opening. The proximal loop can be stiff and attached to the filter
body near the proximal opening. The thrombectomy device can be
deployed distally of a thrombus, then retracted proximally through
the thrombus, with the proximal loop dislodging the thrombus from
the vessel wall. The thrombus can be captured within the filter
body interior, with the filter body elongated during the capture.
One mode of elongation begins with a highly everted filter body and
then decreases the degree of eversion by proximally retracting a
shaft coupled to the filter body proximal end region. The
thrombectomy device carrying the thrombus can later be retracted
within a tubular capture device.
[0015] Filters according to the present invention can be used to
filter vessel regions immediately proximally upstream of a vessel
bifurcation or trifurcation. In one method, the everted filter is
advanced to the region in an elongated, radially reduced state,
then more fully everted, expanding the filter exterior non-everted
walls against the vessel interior walls. The filter can be both
radially expanded and longitudinally shortened to approach and
benignly anchor the filter to the vessel walls, providing coverage
across the vessel proximal of the bifurcation. The filter
effectively covers all the vessel branches distal of the branching,
providing protection. The filter can be located in the region
distal of the trunk but proximal of the branches.
[0016] Everted filters also have the advantage of rendering the
filter relatively independent of the guide wire to prevent unwanted
movement of the filter during motion of the guide wire. In some
methods, the everted filter devices are used primarily to provide
distal embolic protection and are advanced over a guide wire, where
the guide wire can have another device advanced over the guide wire
proximal of the filter. In other methods, the additional proximal
device is used to remove or dilate plaque or thrombus, where the
device is advanced over the filter shaft or tube, which is advanced
over the guide wire. As the proximal device is exchanged over the
guide wire, force is brought to bear on the guide wire, which can
dislodge the guide wire and the filter. The everted filter has the
advantage of rendering the filter comparatively insensitive to
guide wire motion, so that guide wire movements do not as easily
dislodge the filter. In particular, sliding, translational
movements of the guide wire through an everted filter band of the
present invention do not apply significant force on the filter. In
one method, an everted filter is used as the distal end to a guide
wire, where the filter is used primarily as a distal guide wire
anchoring device. In another method, the filter has a tubular
shaft, and the guide wire passes through the tube.
[0017] The everted filters also provide a filter device able to
significantly increase the interior volume of the filter after
positioning the filter in a vessel region. An everted filter can be
advanced to a vessel site in a compressed state, having a small
volume, small profile, and a high strand density due to a small
inter-strand distance and pore size. In place, the filter can be
both elongated and radially expanded to decrease the strand density
and increase the pore size and filter interior volume.
DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of the distal portion of an
everted filter device having a filter body, a shaft, an everted
distal-most region, a fixed distal band, and an axially slidable
proximal band;
[0019] FIG. 2A is a side view of the everting trap of FIG. 1;
[0020] FIG. 2B is a side view of the everting trap of FIG. 1, shown
in an elongated configuration having the proximal band slid
proximally away from the distal band of FIG. 2A;
[0021] FIG. 2C is a side view of the everted filter device of FIG.
2A, shown in axially foreshortened configuration, having the
proximal band slid distally toward the distal band of FIG. 2A;
[0022] FIG. 3A is a fragmentary, longitudinal, cross-sectional view
of an everted filter device everted distal region, having the
filter body interior surface secured to the shaft distal region,
with the filter body biased to evert;
[0023] FIG. 3B is a fragmentary, longitudinal cross-sectional view
of the everted filter device of FIG. 3A, shown in a small profile,
elongated configuration;
[0024] FIG. 3C is a fragmentary, longitudinal, cross-sectional view
of an everted filter device distal region having the filter body
exterior surface mated to the shaft and having a conical shape;
[0025] FIG. 3D is a fragmentary, longitudinal, cross-sectional view
of an everted filter device distal region having the filter body
exterior surface mated to the shaft distal region and having a
separated, diverging everted distal cavity;
[0026] FIG. 3E is a fragmentary, longitudinal, cross-sectional view
of an everted filter device distal region having the filter body
exterior mated to the shaft external surface and having a less
separated, converging everted distal cavity;
[0027] FIG. 3F is a fragmentary, longitudinal, cross-sectional view
of the everted filter device of FIG. 3D, having an atraumatic
tip;
[0028] FIG. 4A is a fragmentary, perspective view of an everted
filter device having a proximal shaft secured to a filter body
proximal region and a distal shaft secured to the filter body
distal region,
[0029] FIG. 4B is a fragmentary, perspective view of an everted
filter device having a proximal shaft coupled to the filter body
proximal region and the distal shaft coupled to the filter body
distal region, with the distal shaft slidably coupled to the
proximal shaft through a collar;
[0030] FIG. 4C is a fragmentary, perspective view of the distal
portion of an everted filter device having a proximal shaft secured
to the filter body proximal region and the distal shaft secured to
the filter body distal region, with the distal shaft slidably
received within a lumen in the proximal shaft;
[0031] FIG. 5A is a fragmentary, perspective view of a filter trap
similar to that of FIG. 4B, but having a curved distal shaft
extending transversely away from the proximal shaft;
[0032] FIG. 5B is a fragmentary, perspective view of an everted
filter device similar to that of FIG. 4C, but having a curved
distal shaft;
[0033] FIG. 5C is a fragmentary, perspective view of an everting
filter similar to that of FIG. 5A, with a doubly curved distal
shaft;
[0034] FIG. 6 is a fragmentary, side view of one frictional lock
device included in some everted filter device devices;
[0035] FIG. 6A is a transverse, cross-sectional view taken through
6A of FIG. 6;
[0036] FIG. 6B is a perspective view of the frictional lock of FIG.
6;
[0037] FIG. 7 is a fragmentary, perspective view of an everted
filter device having a slidable proximal ring and two proximal
filter body openings;
[0038] FIG. 8A is a fragmentary, longitudinal, cross-sectional view
of an everting filter device similar to that of FIG. 4C shown
disposed within a delivery tube prior to use;
[0039] FIG. 8B is a fragmentary, longitudinal, cross-sectional view
of the everting filter device of FIG. 8A after the filter has been
deployed in a vessel and at least partially occluded with filtrate
material;
[0040] FIG. 8C is a fragmentary, longitudinal, cross-sectional view
of the everting filter device of FIG. 8B, after the filter has been
further everted by proximally retracting the distal ring, thereby
distally advancing unoccluded filter material to the distal-most
region of the filter device;
[0041] FIG. 9 is a fragmentary, perspective view of an everting
filter device having a proximal shaft secured to the filter body
mouth region with a filament or string;
[0042] FIG. 10A is a fragmentary, perspective view of an everting
filter device having the filter body everted end coupled to the
shaft and the filter body proximal mouth region coupled to the
shaft through fastening members;
[0043] FIG. 10B is a fragmentary, perspective view of the everting
filter device of FIG. 10A in the fully everted position, where the
fastening members are tethers;
[0044] FIG. 10C is a fragmentary, perspective view of the filter
device of FIG. 10B, shown in a less everted position;
[0045] FIG. 11 is a fragmentary, perspective view of an everting
filter device having a central tube, a proximal filter body mouth
region, and pull strings threaded through the proximal mouth region
and central tube;
[0046] FIG. 12A is a fragmentary, perspective view of an
occluding/filtering device having an occluding distal region, shown
in the occluding position;
[0047] FIG. 12B shows the occluding/filtering device of FIG. 12A in
a more everted, filtering position;
[0048] FIG. 13A is a fragmentary, perspective view of an
occluding/filtering device having a filtering distal region and an
occluding proximal region, shown in the filtering position;
[0049] FIG. 13B is a fragmentary, perspective view of the
occluding/filtering device of FIG. 13A, shown in the more everted,
occluding position;
[0050] FIG. 14 is a fragmentary, perspective view of a drug
delivery catheter sharing some features with the device of FIG.
12A;
[0051] FIG. 15A is a fragmentary, perspective view of an
occluding/filtering device having an inflatable balloon disposed
within a mesh filter body, shown in the inflated, occluding
configuration;
[0052] FIG. 15B is a fragmentary, perspective view of the
occluding/filtering device of FIG. 15, shown in the uninflated,
filtering configuration;
[0053] FIG. 16 is a fragmentary, longitudinal, cross-sectional view
of a thrombectomy device having a proximal tube, a distal shaft
slidably disposed within the proximal tube, a filter mesh filter
body, and a rigid proximal loop, shown disposed distally of a
thrombus;
[0054] FIG. 17 is a fragmentary, longitudinal, cross-sectional view
of the thrombectomy device of FIG. 16, shown after the proximal
loop has dislodged the thrombus and the filter body has captured
the thrombus, with the inner shaft distally extending the filter
body length;
[0055] FIG. 18 is a fragmentary, longitudinal, cross-sectional view
of the thrombectomy device of FIG. 17, after the thrombectomy
device has been partially retracted within a capture tube distal
region;
[0056] FIG. 19 is a fragmentary, longitudinal, cross-sectional view
of the thrombectomy device and capture tube of FIG. 18, after the
thrombectomy device and captured thrombus has been fully retracted
within the capture tube;
[0057] FIG. 20A is a fragmentary, perspective view of an everting
filter device having a bellowed filter body, shown in the compact
configuration;
[0058] FIG. 20B is a fragmentary, perspective view of the everting
filter of FIG. 20A, shown in the extended, elongate configuration;
and
[0059] FIGS. 21A-21F are fragmentary, longitudinal cross-sectional
views of proximal portions of some embodiments of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] The following detailed description should be read with
reference to the drawings, in which like elements in different
drawings are numbered identically. The drawings, which are not
necessarily to scale, depict selected embodiments and are not
intended to limit the scope of the invention. Several forms of
invention have been shown and described, and other forms will now
be apparent to those skilled in art. It will be understood that
embodiments shown in drawings and described above are merely for
illustrative purposes, and are not intended to limit scope of the
invention as defined in the claims which follow.
[0061] FIG. 1 illustrates the distal portion of an everting filter
50. Everting filter 50 may be viewed as having a distal portion 52
and an intermediate portion 54. Distal portion 52 may be further
divided into a distal portion distal region 56 and a distal portion
proximal region 58. The device can extend proximally to a proximal
portion 59.
[0062] Everting filter 50 includes a flexible, mesh, filter body
70. Filter body 70 may be formed of a plurality of wires or strands
which can be used to form the mesh filter body through a variety of
methods, for example, braiding, knitting, weaving, helically
winding, and counterwinding. The mesh can be fused at some or all
of the fiber or strand intersection points. The mesh can also be
electrospun, and formed of sheet or film having holes formed by
laser drilling, punching, dissolving components selectively, and
the like. The strands can be formed of material such as wire, which
can be metallic wire or polymeric wire. The wire may be
substantially circular in cross section or may have any number of
square, rectangular or irregular cross sectional profiles.
[0063] The mesh is preferably self-expanding. The self-expanding
mesh can be formed totally or in part from self-expanding Nitinol,
Elgiloy, titanium, or stainless steel wires and the like, and
combinations thereof. The self-expanding mesh can also be formed of
engineering polymers, for example, liquid crystal polymer, PEEK,
polyimide, polyester, and the like. A preferred mesh is formed of
Nitinol wires, which can be heat set to the desired expanded shape.
The mesh can preferably be heat set to a desired bias shape using
methods such as those disclosed in WO 96/01591, herein incorporated
by reference. Another mesh is highly elastic, and preformed by
mechanical overstress to the desired expanded shape. The mesh is
preferably made radiopaque by means of plating, core wires, tracer
wires, or fillers that have good X-ray absorption characteristics
compared to the human body The mesh may be either partly or totally
radiopaque.
[0064] Filter body 70 may be seen to have a plurality of pores or
openings 74 between the filter body strands or wires. The pores
have an average pore size over the filter body, where the
individual pore sizes may vary depending upon the location over the
filter body. Filter body 70 also has a proximal opening 77 formed
in filter body proximal region 58 using techniques such as those
disclosed in U.S. Pat. No. 6,325,815 (Kusleika et al.), which is
herein incorporated by reference. Filter body 70 may also be
considered to have an interior within the filter body and an
exterior defined outside of the filter body. Filter body 70 further
includes an interior surface 72 and an exterior surface 68. Filter
body 70 may be seen to extend from a first end region 62 to a
second end region 60. Filter body 70 includes an intermediate
region 61 disposed between first end region 62 and second end
region 60. Filter body proximal opening 77 may be seen to have a
proximal opening mouth region 75 forming the circumference of the
opening.
[0065] An elongate shaft 80 may be seen to extend distally from
proximal region 59 and further distally within filter body 70.
Unless otherwise noted, shafts in the present invention may be
considered to be elongate members generally, being tethers, solid
shafts, and tubes in various embodiments. Shaft 80 is a solid shaft
in one embodiment, and can have at least one lumen therethrough,
forming a tube, in other embodiments.
[0066] Shafts can be metallic, and formed of Nitinol, stainless
steel, Elgiloy or other springy materials, mono-filament or
multi-filament, for example, stranded or cable. The shafts can be
tapered or have a uniform diameter over their length. Shafts can
have a circular, flat, or other cross-sectional shape. The shafts
can be single member or multi-member, for example, parallel
independent structures. Shafts can be coiled and polymer coated as
well as tubular and having a slippery coating.
[0067] Some shafts are entirely polymeric, for example, formed of
engineering polymer, PEEK, polyimide, polyester, PTFE, and the
like. Polymeric shafts can be reinforced with metals or stiff
polymers in the form of braids, coils, sheets, ribbons, and the
like. Shafts can be partly or entirely constructed of ceramics.
[0068] Filter body 70 can be slidably coupled to shaft 80, for
example, by a proximal band, ring, bushing or collar 66, typically
formed of metal and preferably radiopaque. In some embodiments, the
slidably mounted bands or rings have a lubricious interior, and can
be formed in part or totally from PTFE. Filter body second end
region 60 can be axially, fixedly attached to shaft 80 with a
distal band, ring, or collar 64. Filter body 70 has an everted
shape. The everting aspect of filter body 70 may be considered to
divide the filter body exterior surface into a non-everted region
76, proceeding to a distal-most region 78, proceeding further over
the surface to an everted surface region 82. The everted shape of
filter 70 defines an everted cavity or concave region 83 bounded by
filter body everted surface region or cavity side walls 82 and the
filter body distal-most extent. It may be seen from inspection of
FIG. 1 that axially translating proximal ring 66 relative to distal
ring 64 while holding the filter body diameter consistent may
change the degree of eversion of filter body 70. The filter
material occupying distal-most region 78 may therefore change with
the degree of eversion of filter 70, with different locations of
filter body 70 being distal-most varying as a function of the
degree of eversion. The length of a distal cavity 83 will increase
with increasing eversion.
[0069] The everting nature of the filter bodies may be further
understood with reference to a common article of clothing, a sock.
A sock may be removed, allowed to hang toe downward, a hand
inserted within the interior, the distal toe region pinched with
fingers from within, and the pinched region pulled upward, forming
an everted toe region which is pulled inside out to form an
exterior distal cavity or dimple near the closed end of the sock.
The open end of the sock has a proximal opening bounded by a
proximal mouth region. The degree of eversion of the sock may be
increased by moving the pinched region upward or the open end
downward, increasing the amount of material within the distal
exterior cavity. The term filter sock may be used interchangeably
with filter body in describing and claiming the present
invention.
[0070] FIG. 2A illustrates everting filter body 70 from the side in
a first configuration. Filter body 70 has a diameter indicated by
D1 and a length L1. Filter body non-everted exterior surface 76,
distal-most exterior surface region 78, and everted surface region
82 is as previously discussed with respect to FIG. 1. The relative
locations of filter body first end region 62 and second end region
60 may be noted.
[0071] FIG. 2B further illustrates filter body 70 in a more
elongated configuration relative to that of FIG. 2A. Filter body 70
has a diameter as indicated at D2 and a length as indicated at L2.
It may be seen from inspection of FIG. 2B that diameter D2 is
smaller than that of FIG. 2A and length L2 is greater than that of
FIG. 2A. The configuration of FIG. 2B illustrates the elongatable
nature of the filter body, which can be used to decrease the
profile. The decreased profile configuration can be used to dispose
the radially reduced filter body within filter delivery devices and
tubes. The radially reduced aspect may also be used to insinuate
the filter into small diameter body vessels, for example, distal
blood vessels.
[0072] FIG. 2C further illustrates filter body 70 in yet another
configuration. In FIG. 2C, filter body 70 has a diameter D3 greater
than that of FIG. 2A, and a length L3, less than that of FIG. 2A.
The configuration of filter body 70 in FIG. 2C illustrates one
configuration which may be used to expand the diameter of the
filter to occupy a body conduit or vessel when the filter body is
to be expanded against the vessel walls to substantially preclude
fluid flow from bypassing the filter. The axial translation of
proximal ring 66 relative to distal ring 64 may be seen to have
varied both the length and diameter of the vessel in FIGS. 2A-2C.
It may be seen from inspection of FIG. 2A that distally translating
proximal ring 66 relative to distal ring 64 can also increase the
degree of eversion of filter body 70, rather than increasing the
diameter. This aspect of the invention will be discussed
further.
[0073] Referring again to FIG. 1, one method forming the everted
filter shape may be further discussed. Everting the filter can
include everting the distal region of the filter body material to
form the everted distal cavity bounded by the filter body exterior
surface, as previously discussed. The filter body exterior surface
may then be disposed around the exterior surface of the shaft
distal end. The filter material exterior surface can then be
operably coupled or mated to the shaft distal end exterior surface.
The coupling of the filter exterior surface to the shaft may be
accomplished by any method suitable for the filter body material.
Various materials may be suitable for fixing using welding,
braising, soldering, solvent welding, adhesives, and crimping. The
filter body may also be fixed to the shaft using a band, for
example, distal band 64 previously discussed. In a preferred
embodiment, distal band 64 and the second end region of the filter
body are fixed with respect to translation and rotation relative to
shaft 80. In one embodiment, distal band 64 is fixed only with
respect to translation, being allowed to rotate about shaft 80.
This can be accomplished, for example, by enlarging the extreme
distal end of shaft 80 to be larger than the inside diameter of
distal ring 64. This method of everting the filter body may be seen
from inspecting FIG. 1.
[0074] Proximal ring 66 may be used in various ways to slidably
couple body first end region 62 to shaft 80. In one embodiment,
proximal ring 66 is used to gather together and bind the extreme
proximal end of a cylindrical tube of filter material, where the
filter material can be fixed or adhered to the ring interior, and
even folded back distally over the ring exterior and secured to the
ring exterior using adhesion or further crimping. In some
embodiments, the filter material itself slides axially over the
shaft, being gathered and held in place by the proximal ring.
[0075] Filter body 70, along with first end region 62, second end
region 82, distal cavity 83, distal-most region 78, non-everted
region 76, and proximal opening 77 is used to refer to parts of the
everting filters generally. The same reference numbers are used to
refer to these locations for different filters, even though the
filters are not identical and the same reference numerals may
reference slightly different physical elements of different
filters. It should also be understood that distal-most region 78 is
used to refer to a region having an area and a length, rather than
a point of tangency. The distal-most region may often refer to an
annular shape having a cross-sectional area at least about half the
cross sectional area of the filter at its widest part.
[0076] Referring again to FIGS. 2A-2C, one use of the everted
filter to protect bifurcated and trifurcated vessel may be
discussed. Filter body 70 has an elongated shape and small profile
in FIG. 2B, which can be used to advantage to advance the filter to
a vessel site through narrowed vessel regions, for example, past a
stenosed vessel region. Once in position, a wide profile to occupy
the entire vessel cross section is desirable, as is a large
interior collection volume for the filter. The filter can be made
to assume a wide profile by bringing the filter first and second
end regions together to shorten the filter length and increase the
filter outer diameter. Such a shape may be seen in FIG. 2C.
[0077] In one use, filter body 70 can be advanced past a treatment
site that is located immediately proximal of a bifurcation or
trifurcation. The filter can be expanded to the bifurcation and
then expanded to both deploy the filter material across all the
branch vessels and to increase the collection volume of the filter,
as in FIG. 2C.
[0078] Filter body 70 in FIG. 2C also illustrates another advantage
of the present invention. A large profile filter body 70 can be
used to anchor the filter against the interior vessel walls to
stabilize the position of the filter. A guide wire can be passed
through a lumen in shaft 80, and may continue distally past distal
cavity 83. Proximal of filter body 70, other devices such as
angioplasty devices, guide catheters, and atherectomy devices may
be removed over the guide wire and replaced with other devices also
passed over the guide wire. This use of the guide wire can act to
dislodge the guide wire, which may have taken significant time and
effort to position correctly. The movement of the guide wire can
also dislodge previous filter devices passing over the guide wire.
The anchoring of filter body 70 against the vessel walls allows a
guide wire to pass through a lumen in the filter device, with the
filter body being able to remain in place and resist movement
caused by the guide wire. Another way to accommodate wire motion is
for the wire motion to cause more or less filter eversion. The
length of non-everted region 76 may vary in response to wire
motion, but the proximal portion of non-everted region 76 will
contact the vessel wall at an unmoving position.
[0079] FIG. 3A illustrates an alternate embodiment in the present
invention for forming an everting filter 90, with the distal region
only being shown. In the embodiment of FIG. 3A, the filter everting
is accomplished by biasing the filter body 70 to assume an everted
shape when unconstrained. The bias to assume the everted shape may
be provided by heat setting the material to assume the everted
shape when unconstrained. In one example, Nitinol wire braid can be
heat set to assume the shape shown in FIG. 3A when not constrained
by a surrounding delivery tube, and to assume the shape shown in
FIG. 3B when constrained by extreme proximal tension put on filter
body 70 from the proximal end. Everting filter 90 may be seen to
share some aspects of the invention previously discussed. Filter
body 70 may be seen to have interior surface 72 and exterior
surface 68. Filter body 70 may be seen to extend from noninverted
region 76, to a distal-most region 78, and further to everted
region 82. Everted region 82 defines an everted cavity or concave
region 83 within, bounded by distal-most region or extent 78. In
FIG. 3A, shaft 80 may be seen to have a distal end region 81 having
a shaft exterior surface 85 thereabout. Filter body 70 may be seen
to have interior surface 72 which is mated about shaft distal end
81, to exterior surface 85. The filter body interior surface can
thus face the shaft exterior surface directly. In the example
illustrated, distal ring 64 is disposed about filter body 70 and
shaft distal end region 81. A proximal-most extent of everted
cavity 83 is indicated in FIG. 3A at 92.
[0080] FIG. 3B illustrates everting filter 90 of FIG. 3A, in a
reduced profile configuration. Filter body 70 has been proximally
retracted from distal ring 64. The configuration of FIG. 3B may be
understood to be a constrained configuration, maintained only by
proximally drawing filter body 70 and preventing filter body 70
from freely assuming the unconstrained configuration illustrated in
FIG. 3A. The location 92, previously the proximal-most extent of
the everted cavity of FIG. 3A may be noted in FIG. 3B. Everting
filter 90, having the alternate everting distal region, has one
advantage which may be apparent from inspection of FIG. 3B. In
particular, everting filter 90 can have a very low profile or
distal outer diameter when in the configuration of FIG. 3B. It is
not necessary for filter body 70 to extend distally from within
distal ring 64, everting, then extending proximally back over shaft
80. The embodiment of FIG. 3B can be useful where an extremely low
profile distal region is required, for example, for traversing
narrow and/or tortuous distal vessel regions.
[0081] FIG. 3C illustrates another embodiment of the invention in
everting filter 94. Filter 94 includes referenced features
previously discussed. Everting filter 94 includes a more conical
shape than that of the embodiments previously discussed. Everting
filter 94 also illustrates the mode of attachment of filter body to
shaft in one preferred embodiment. Filter body 70 includes interior
surface 72 and exterior surface 68, previously discussed. Exterior
surface 72 may be seen facing and mated to shaft exterior surface
85, using methods previously discussed. Distal ring 64 is further
disposed about both filter body 70 and shaft and distal region 81.
The filter body surface non-everted region 76, distal-most region
78, and everted region 82 may be seen. Everted cavity 83 may also
be seen, being very small in FIG. 3C. FIG. 3C illustrates a
constrained configuration of everted filter 94, which would more
fully evert, increasing the volume of everted cavity 83 and length
of everted region 82, should filter 70 be allowed to distally
travel to an unconstrained configuration.
[0082] FIG. 3D illustrates the distal region of another everting
filter 96. Filter 96 includes referenced features previously
discussed. Everted cavity 83 may be seen formed by everted region
82 and distal-most region 78. The shape of everted cavity 83 may be
seen to be widely separated, formed by a funnel shape to the
everted surface walls, where the funnel shape diverges outwardly
over the length of the cavity. In particular, the minimum inside
diameter of everted cavity 83 is indicated at D5. This minimum
inside diameter D5 may be seen to be approximately equal to that of
D4, the outside diameter of shaft 80. In the embodiment
illustrated, the everted cavity minimum inside diameter is not less
than that of the shaft outside diameter, and in some embodiments,
can be much greater than the shaft outside diameter.
[0083] FIG. 3E illustrates yet another embodiment of the invention
in everted filter 98. Filter 98 has a much less separated everted
cavity 83 than that of FIG. 3D. In particular, while the walls of
the everted cavity may he seen to diverge over the cavity length in
FIG. 3D, the embodiment of FIG. 3E shows the walls distally
converging, then diverging. The everted cavity minimum inside
diameter is indicated at D7. D7 may be seen to be significantly
less than outer diameter D4 of shaft 80.
[0084] FIG. 3F illustrates still another embodiment of the
invention in everted filter 99. Everted filter 99 includes
referenced details previously discussed with respect to other
embodiments. Everted filter 99 also includes a distal tip 97,
terminating in an atraumatic and preferably radiopaque safety tip
95. Distal tip 97 may be useful for insinuating the everting filter
into narrow and/or tortuous vessel regions. In particular, distal
tip 97 may be used to at least partially align everting filter 99
with the desired orientation indicated by the at least partially
insinuated distal tip 97.
[0085] Tips can be metallic, and formed of Nitinol, stainless
steel, Elgiloy or other springy materials, mono-filament or
multi-filament, for example, stranded or cable. The tips can be
tapered or have a uniform diameter over their length. Tips can have
a circular, flat, or other cross-sectional shape. The tips can be
single member or multi-member, for example, parallel independent
structures. Tips can be coiled and polymer coated as well as
tubular and having a slippery coating.
[0086] Some tips are entirely polymeric, for example, formed of
engineering polymer, PEEK, polyimide, polyester, PTFE, and the
like. Polymeric tips can be reinforced with metals or stiff
polymers in the form of braids, coils, sheets, ribbons, and the
like. Tips can be partly or entirely constructed of ceramics. The
tips are preferably made radiopaque by means of the metal chosen or
by means of radiopaque additions such as fillers added to polymer
based tips.
[0087] FIG. 4A illustrates an everting filter device 100, including
a filter body 70, previously discussed. Everting filter device 100
includes a first or proximal shaft 102 fixedly attached to filter
body 70 with proximal ring 110. In the embodiment illustrated, a
portion of filter body 70 is secured to proximal ring 110. In one
example, a portion of filter body 70 may be pulled through a
channel in proximal ring 110 and secured within. In another
example, a portion of filter body 70 may be secured to the outside
of proximal ring 110. In yet another example, a portion of filter
body 70 may be disposed within ring 110, between the ring inside
wall and the inserted proximal shaft distal end 106.
[0088] Filter body 70 may be seen to have a proximal mouth region
114 defining proximal opening 112 therein. In some embodiments,
proximal mouth region 114 may be formed of the knitted proximal
extent of filter body 70. FIG. 4A illustrates how a tubular filter
body may be used to form the present invention, by utilizing the
existing proximal filter body opening of the filter body as the
everting filter proximal opening. This may be contrasted with using
the existing filter body proximal opening to secure the filter
first end region about the proximal shaft, thereafter creating the
proximal opening by extremely enlarging at least one of the mesh
pores. Filter body 70 first end region 62 may thus be secured using
a small portion of preexisting proximal mouth region 114.
[0089] In a preferred embodiment, the proximal opening is made by
constraining the ends of a braided tube with bands, then forcing a
pointed mandrel through the wall of the braid near the proximal
band, and heat setting the braid to this configuration. The mandrel
can have a tapered end which forces a pore opening wider as the
mandrel is inserted further. The mandrel can also be worked within
the selected pore to increase the size. Some methods of forming a
proximal opening are described in U.S. Pat. No. 6,325,815, and in
U.S. Published Patent Application No. 2002/0004667, both herein
incorporated by reference.
[0090] A second or distal shaft 104 may also be seen, having a
distal end region 108 secured to filter body second end region 60
using distal ring 64. The relative locations of proximal ring 110
and distal ring 64 to each other can change the size of everted
cavity 83 and the length or amount of everted filter material 82.
Either shaft 102 or 104 may be solid shafts or have lumens
therethrough, depending upon the embodiment. In some embodiments,
both proximal shaft 102 and distal shaft 104 may be slidably
disposed within a tube or otherwise mounted in a side-by-side
slidable relationship to each other. The use of the terms proximal
and distal to refer to shafts 102 and 104 respectively are used for
explanation, and refer to the configuration resulting in the
everted filter, as shown in FIG. 4A. It should be understood that,
in the example of FIG. 4A, distal shaft 104 could be retracted
proximally of proximal shaft 102.
[0091] FIG. 4B illustrates an everting filter device 120, including
many of the referenced elements of FIG. 4A, which may be understood
with reference to the discussion of FIG. 4A. Everting filter 120
includes proximal shaft 102 and distal shaft 104 as previously
discussed. Everting filter device 120 can further include a ring or
collar 122 which, in various embodiments, can be fixedly attached
to either of proximal shaft 102 or distal shaft 104, but not both.
The shaft which is not fixedly attached to collar 122 is preferably
slidably received within collar 122. Collar 122 thus allows one
shaft to be maintained in at least a partially, controlled and
parallel configuration relative to the other shaft. One shaft may
be held stationary while the other shaft is slidably translated
through collar 122. In FIG. 4B, proximal shaft 102 is illustrated
as fixed to collar 122 while distal shaft 104 is illustrated as
being slidably received within collar 122.
[0092] FIG. 4C illustrates an everting filter device 124 including
filter body 70 secured to distal shaft 104 at distal region 108
with distal ring 64. Everted distal cavity 83 may be seen, as
previously discussed. Filter body 70 includes proximal mouth region
114 and proximal opening 112. In everting filter device 124, distal
shaft 104 is disposed within a lumen 128 within proximal shaft 102.
Proximal shaft 102 may be seen to terminate distally at a proximal
ring 126. Proximal ring 126 may be seen to secure filter body 70 to
proximal shaft 102. In filter device 124, the degree of eversion of
filter body 70 may be controlled by slidably translating distal
shaft 104 within proximal shaft 102.
[0093] In some embodiments, as will be further discussed, proximal
mouth region 114 can be reinforced with a proximal loop. The
proximal loop can be threaded through at least one portion of
filter body 70. In some embodiments, filter body 70 may not be
sufficiently strong or biased to expand radially and may rely at
least in part on the self-expanding nature of the proximal loop.
Some suitable proximal loop designs are described in European
Patent Document No. EP 1181900, herein incorporated by
reference.
[0094] FIG. 5A illustrates an everting filter device 130, similar
in some respects to everting filter device 120 of FIG. 4B. Device
130 includes proximal shaft 102, distal shaft 104, collar 122, and
filter body 70, all as previously discussed. Everting filter device
130 differs from device 120 of FIG. 4B in the curved shape of the
distal portion of distal shaft 104. Distal shaft 104 includes an
intermediate region 131 disposed proximal of collar 122.
Intermediate region 131 may be seen to be parallel with proximal
shaft 102 and, in this region, directly in line with the proximal
portion of distal shaft 104. Distal shaft 104 may be seen to
include a first region continuing distally past collar 122,
indicated at 132. This region may be seen to extend distally from
distal shaft region 131. Continuing further distally, a transverse
section 132 continues transversely away from the longitudinal axis
of proximal shaft 102, extending more toward the center of filter
body 70 interior. Continuing distally from transverse region 134, a
distally extending region 136 may be seen, which extends
substantially parallel to proximal shaft 102 and distal shaft
intermediate region 131.
[0095] It may be seen from inspection of FIG. 5A that curved or
transverse region 134 can act as a limit to the proximal travel of
distal shaft 104. Transverse region 134 may be seen to extend at a
first, proximal elbow or transition region 138, and then extend
transversely and distally toward a second, distal elbow or
transition region 140. In some embodiments, transverse region 134
may extend perpendicular to proximal shaft 102 and distal shaft
region 131. In the embodiment illustrated, transverse region 134
extends transversely while extending distally. The transversely
extending or curved distal region shafts of the present invention
can serve to center the filter bodies.
[0096] As distal shaft 104 is withdrawn proximally, elbow 138 will
ultimately be drawn to contact collar or stop 122. At this point,
further proximal travel of distal shaft 104 will be prevented or at
least hindered, depending on the embodiment. In some embodiments,
this serves to limit the proximal travel and limit the degree of
eversion of the filter body. In other embodiments, first elbow 138
can serve to provide the treating physician with tactile feedback
as to the degree of eversion. In some embodiments, transverse
region 134 can be retracted through collar 122, after a threshold
degree of tensile force is applied to distal shaft 104. Transverse
regions such as transverse region 134 can thus serve to control the
degree of filter eversion and can act to prevent the inadvertent
over-eversion, reversing the relative locations of the distal and
proximal regions. In some embodiments, elbows 138 and 140 are
heat-set and biased to assume the shape illustrated in FIG. 5A, but
are sufficiently malleable to allow transverse region 134 to be
fully retracted through collar 122. This aspect can be useful where
a small profile is desired for delivery, followed by the expansion
to the unconstrained configuration illustrated in FIG. 5A.
[0097] FIG. 5B illustrates another everting filter device 140,
which is similar in many respects to everting filter device 124 of
FIG. 4C. Everting filter device 140 shares many of the aspects of
device 124 of FIG. 4C, and uses the same reference numerals to
describe these aspects. Everting filter device 140 includes
proximal shaft 102 having a lumen 128 therethrough which slidably
receives distal shaft 104. Proximal shaft 102 extends distally to
proximal ring 126 which secures filter body 70 to the proximal
shaft. Filter device 140 differs from filter device 124 in having a
curved or transverse region 144 in distal shaft 104. Distal shaft
104 includes a region 141 disposed proximal of proximal ring 126,
extending distally to a first region 142 disposed distally of
proximal ring 126 and in line with distal shaft region 141 and
proximal shaft 102. Continuing distally, distal shaft 104 includes
a transverse region 144 which extends distally and transversely
away from proximal shaft 102. In some embodiments, transverse
region 104 extends perpendicularly and transversely away from
proximal shaft 102. In the embodiment illustrated in FIG. 5B,
transverse region 144 extends distally while extending transversely
more toward the center of the filter body interior.
[0098] Continuing distally, distal shaft 104 has a third region 146
extending distally from transverse region 144 and substantially
parallel to proximal shaft 102 and distal shaft region 141.
Transverse region 144 can serve the same purpose as transverse
region 138 of device 130 in FIG. 5A. Specifically, transverse
region 144 can serve to limit the proximal travel of distal shaft
104, thereby limiting the degree of eversion of filter body 70.
Transverse region 144 can also serve to provide tactile feedback to
the treating physician as to the configuration of the everting
filter body.
[0099] FIG. 5C illustrates yet another embodiment of the invention
in everting filter device 150. Device 150 is similar in many
respects to device 130 of FIG. 5A. Device 150 shares many of the
same aspects of the invention as device 130 and utilizes identical
reference numbers in referencing these aspects. Everting filter
device 150 includes distal shaft 104 having region 132 as discussed
with respect to device 130. Continuing distally, distal shaft 104
passes through an elbow 156 then to a first transverse region 152,
which extends transversely away from proximal shaft 102 while
extends distally away from shaft 102. Distal shaft 104 then passes
through a second elbow 158, then extends distally away from
proximal shaft 102 while extending transversely back toward
proximal shaft 102.
[0100] Distal shaft 104 then continues along a straight region 162,
then joining distal ring 64. Distal shaft 104 may be seen to have a
first transverse region 152 which extends transversally past a
center line of filter body 70 and transversally past a center line
drawn through distal ring 64. Distal shaft 104 then doubles back
and extends back toward the direction from which it came. The
u-shape to the distal shaft region within filter body 70 can serve
to provide tactile feedback and as a limit or restraint on proximal
travel of distal shaft 104 as previously discussed. The extreme
degree of transverse travel of transverse region 152 can also serve
to provide some structural support for filter body 70 in the open
position, and can act to open filter body 70 where the filter body
itself may benefit from assistance in maintaining or re-attaining
the open shape, for example, after being constrained within a
delivery catheter or device.
[0101] FIG. 6 illustrates in more detail one embodiment of a
frictional lock which can be used with the present invention. A
frictional lock 170 is provided, and can be used in place of collar
122 depicted in FIG. 5A. Distal shaft 104 and proximal shaft 102
are illustrated as before. A proximal ring 172 and a distal ring
174 are illustrated disposed of either side of frictional lock 170.
The relative sizes of the proximal and distal rings are not
necessarily to scale. The relative locations of proximal and distal
rings 172 and 174 relative to frictional lock 170 are also not
necessarily to scale.
[0102] In some embodiments, the rings 172 and 174 are disposed
significantly further apart than illustrated in FIG. 6, and can
serve as the distal and proximal limits to travel of distal shaft
104, and therefore the limits to the degree of eversion of filter
70. In other embodiments, rings 172 and 174 may be closer together.
FIG. 6A illustrates frictional lock 170, having distal shaft 104
inserted through a top lumen 176 and filter body shaft 102 inserted
through a bottom lumen 178. In one embodiment, proximal shaft 102
is fixedly secured within bottom lumen 178, and is not free to
slide. Distal shaft 104 is disposed of top lumen 176, being free to
slide actually through the lumen. Distal ring 174 may be seen as
exceeding the diameter of lumen 176 and preventing or inhibiting
travel therethrough. FIG. 6B further illustrates lock 170 in a
prospective view.
[0103] In some embodiments, rings 172 and 174 do not serve to limit
the travel the distal shaft 104, but instead provide resistance to
travel when exceeding either ring travel limit. In particular, the
rings may serve to provide a perceptible bump, giving tactile
feedback to the treating physician that a limit has been exceeded.
In these embodiments, the limit of travel of the rings may be
exceeded prior to deployment of the filter, for example, while the
filter is constrained within the delivery device or sheath. A
frictional lock such as lock 170 may be used on either the distal
or proximal shaft and may also be disposed at the proximal end of
the device in some embodiments. The rings may be replaced in some
embodiments with more gradual bulges or raised regions.
[0104] A lock is formed by the bent wire regions 138/140, and
156/158 in FIGS. 5A and 5C respectively. When the bent wire is
pulled into the collar the wire will resist straightening, and a
frictional force of the wire against the collar will effectively
lock the wire/mesh relative to the collar/other wire.
[0105] FIG. 7 illustrates yet another everting filter device 180
including filter body 70 as previously discussed. Everting filter
device 180 includes both a first proximal opening or port 186 and a
second proximal opening or port 188. The present invention may
include several proximal openings for allowing fluid flow into the
filter body. In one example, the filter body is formed by gathering
together and securing the preexisting proximal mouth region of a
tubular cylinder. Existing pores through the filter body wall may
then be significantly enlarged by inserting ever larger members
through the mesh. The enlarged pores are desirably heat set to
maintain their enlarged shape. In these and other embodiments, it
may be advantageous to form the large cross-sectional area openings
of the present invention by forming 2, 3 or 4 openings through the
proximal region of a filter body to thereby increase the opening
surface area and distribute the openings more symmetrically about
the shaft.
[0106] FIG. 7 also illustrates a proximal ring 199 useful with the
present invention. Ring 199 includes an inner ring 190 which is
slidably disposed over shaft 182 with a lumen 198. Filter body or
mesh material may be seen gathered over inner ring 190 at 192. A
second or outer ring 194 may then be disposed over gathered
material 192 and inner ring 190. Outer ring 194 may then be secured
to filter body material 192 and inner ring 190 through any suitable
method, including crimping, as illustrated in FIG. 7.
[0107] Everting filter device 180 also illustrates shaft 182 having
a distal region 184 which is biased to gradually slope away from
the portion of shaft disposed proximally of ring 199. Shaft distal
region 184 may be described as forming a gradual curved transition
from the proximal ring to the distal ring where the distal ring is
made to be transversally offset from a line drawn through the shaft
proximal of the proximal ring. As may be seen from inspection of
FIG. 7, the biased, distal transition region 184 can act to at
least partially open filter body 70. In some embodiments, biased
transition region 184 can also act to center filter body 70 within
a vessel. Transition region 184 can be biased by heat setting the
shaft material. In one example, shaft 182 and transition region 184
are formed of Nitinol, and are heat set to assume a gradual
transversally sloping shape when unconstrained.
[0108] FIG. 8A illustrates an everting filter device 200, similar
in some respects, to that described with respect to FIG. 4C.
Everting filter device 200 is disposed within a delivery tube or
catheter 202 which is in turn disposed within a lumen 221 of a body
vessel or conduit 222. Delivery tube or catheter 202 can have a
distal region 206 and a lumen 204 therethrough. Everting filter
device has a filter body 70 including a non-inverting exterior
surface region 76, a distal-most region 78, and an everted exterior
surface region 82 defining an everted cavity 83 therein. Filter
body 70 may also be seen to have a first proximal opening 216.
Everting filter device 200 includes a distal shaft 208 slidably
disposed through a proximal shaft 210 which includes a lumen
therethrough. Proximal shaft 210 terminates distally at about
proximal ring 212, which also serves to secure filter body 70 to
proximal shaft 210. Distal shaft 208 is secured to filter body 70
at distal ring 214. In a preferred embodiment, distal ring 214 is
fixedly secured to distal shaft 208 and proximal ring 212 is
fixedly secured to proximal shaft 210, but allows distal shaft 208
to axially slide through proximal ring 212. The degree of eversion
of filter body 70 must thus be controlled by the relative distances
between proximal ring 212 and distal ring 214, by the translating
movement of shaft 208.
[0109] FIG. 8B illustrates everting filter device 200 after thc
device has been distally advanced from delivery catheter 202 and
radially expanded and deployed within vessel 222. Vessel 222 can be
any of the coronary, carotid, renal, peripheral, cerebral,
neurological, and other blood vessels. Everting filter device 200
can find one exemplary and advantageous use in the narrow and
tortuous neurological blood vessels. Delivery catheter 202 may, in
some uses, be proximally retracted entirely from the body. Body
fluid flow, for example, blood flow, may extend through filter body
70, entering through proximal openings 216, continuing through the
filter, and exiting through distal-most region 78. After a period
of time, filtrate material 220 may collect in the distal-most
region of the filter. After sufficient time, the pressure drop
across the device 200 may become too great, even totally occluding
flow through the filter. In prior art devices, at this point in
time, the filter would typically be proximally retracted into a
capture device and removed from the body. The present invention
allows changing the eversion of the filter to provide fresh,
unoccluded surface area to be presented to the body fluid flow,
thereby postponing the need to remove the filter device from the
body, and extending the filter capacity of the device. The length
of everted exterior surface material 82 may be noted in FIG.
8B.
[0110] FIG. 8C illustrates everting filter device 200 after the
filter has been further everted. Distal shaft 208 has been
proximally retracted, thereby decreasing the distance between
proximal ring 212 and distal ring 214. This also decreases the
distance between the first and second ends of filter body 70. The
volume of the everted cavity 83 may be seen to increase from FIG.
8B to FIG. 8C. Filtrate 220 may be adhered to the side walls of
everted cavity 83. This is common in filtrate materials which tend
to stick together, for example, thrombus or grumous. The length of
everted filter material 82 may be seen increased from FIGS. 8B to
8C as well. Distal-most region 78 of everting filter device 200 is
now once again a porous region, permitting fluid flow therethrough.
The present invention thus allows fresh filter media to be
presented to a perfusing bloodstream without requiring the removal
of the filter from the patient's body.
[0111] After a period of time, the distal-most region such as
region 78 of FIG. 8C may also become occluded, and distal ring 214
proximally retracted again, further providing additional unoccluded
filter material to the body fluid being filtered. This process may
be continued as long as desired, or until the filtrate capacity of
everting filter device 200 has been reached. The degree of eversion
of filter body 70 may be either increased or decreased to present
unoccluded filter material to the blood flow, depending on the
device and the initial degree of eversion. At this time, everting
filter device 200 can be proximally retracted into capture device,
for example, into the lumen of the delivery device, such as
delivery tube 202, previously discussed. Alternatively, a separate
recovery catheter (not shown) can be used. In an alternate
embodiment, recovery of filter device 200 is effected by extending
distal shaft 208 relative to proximal shaft 210 so as to extend the
filter and reduce its diameter. In this configuration, filter
device 200 can be withdrawn from the body without use of a capture
device.
[0112] FIG. 9 illustrates another everting filter device 240,
similar in some respects to everting filter device 100 of FIG. 4A.
Everting filter device 240 includes the proximal shaft 102 and
proximal ring 110 previously discussed, as well as distal shaft 104
and distal ring 64. Filter body 70 includes distal everted cavity
83. Device 240 further includes a proximal opening 246 defined
within a proximal mouth region 242. Proximal mouth region 242 may
be seen to include a proximal loop 244 within. Proximal loop 242
may be seen to extend around the circumference of proximal mouth
region 242 and be secured to proximal ring 110. In embodiments
where the proximal mouth region has been formed by piercing the
filter sidewall as previously discussed, the loop can remain
secured in the filter body by simply intertwining the loop in the
filter. In devices where the proximal mouth region has been
produced by cutting the filter such that loose ends of filter
strands are present, it will be desirable to weld, bond, or
otherwise join at least some of the filter body strands so as to
prevent filter unraveling or separation with subsequent
disconnection of the loop from the proximal mouth region.
[0113] In some embodiments, filter body 70 is of sufficient
strength and is sufficiently biased outward so as to not require
any support from proximal loop 244. In this embodiment, loop 244
may be a string, serving as a drawstring though proximal mouth
region 242. In other embodiments, filter body 70 may require, or
benefit from, an outward radial force applied to proximal mouth
region 242. In this embodiment, loop 244 may be formed of a
stronger, wire material. In one example, loop 244 is formed of
Nitinol or another wire biased to assume a substantially circular
cross-sectional profile as illustrated in FIG. 9. Loop 244 may be
entirely separate from the filter body 70, being affixed only to
the proximal band 110, may be intertwined with the mouth of the
filter body over much of the proximal mouth region 242, or may be
looped through a discreet region of the filter body, most desirable
through the region of the filter body diametrically opposed to the
proximal band 110. A loop may be optimally attached to distal band
64 and provide radial expansion to filter body 70. This may be
particularly advantageous when filter device 240 is used near
bifurcations. The loop may be attached to a separate proximal ring
and interwoven through the filter. Loop 244 may serve as both a
proximal mouth region expansion and supporting device, as well as a
closure device should everting filter device 240 be proximally
retracted within a smaller profile capture device. The loop is
preferably partly or entirely radiopaque so as to facilitate
visualization of the proximal mouth region under fluoroscopy.
Proximal loops are discussed in detail in European Patent Document
No. EP 1181900, previously incorporated by reference.
[0114] FIG. 10A illustrates another everting filter device 250.
Everting filter device 250 has only a single shaft 252 terminating
in a ring or collar 254. Filter body 70 includes end region 62
terminating in a proximal mouth region 256. Filter body second end
region 60 may be seen coupled directly to collar 254 and shaft 252.
Proximal mouth region 256 may include a proximal loop or string
within, as previously discussed, in this figure shown intertwined
in the filter body 70 and not attached to collar 254. Everting
filter device 250 further includes fastening members 260 coupling
shaft 252 to filter body 70 via collar 254 and proximal mouth
region 256. In one embodiment, fastening members 260 are struts,
having significant strength in compression, and are coupled to a
proximal loop disposed about mouth region 260. Struts 260 can thus
act to maintain filter body 70 in an open position, thereby
maintaining the patency of the proximal opening 258. In some
embodiments, struts 260 are biased to splay outwardly or to assume
an arcuate position when unconstrained. Support members or struts
260 can thus serve to radially expand filter body 70 when deployed
from a filter delivery device.
[0115] FIG. 10B illustrates everting filter device 250 in a
maximally everted state, where filter body second end region 60 is
proximally retracted and fastening members 260 are proximally
extended. FIG. 10C illustrates everting filter device 250 where
shaft 252 has been maximally distally extended, thereby changing
device 250 to the minimally everted state. Support members 260 may
be seen as taut and maximally distally deployed. Where fastening
members 260 are tethers, device 250 may be deployed in
configurations intermediate those of 10B and 10C, thereby gradually
increasing or decreasing the degree of eversion of filter 70.
Device 250 may find one use where proximal mouth region 250 would
expand radially outward beyond the vessel boundaries, thus fixing
the location of the filter within the vessel and providing support
for maintaining the filter position as filtrate is collected within
the filter interior. In particular, as more filtrate is collected,
device 250 may be gradually switched from the configuration of FIG.
10C to that of FIG. 10B. Device 250 may then be proximally
retracted into a capture device, with fastening members 260
assisting in closure of proximal mouth region 256 as the filter is
retracted and proximal opening 258 is closed. Device 250, as shown
in FIGS. 10B-10C, further illustrates that filter body 70 can
maintain a stable position in a vessel despite large motions of
shaft 252.
[0116] FIG. 11 illustrates an everting filter device 280 having a
shaft 284 terminating distally in a distal ring or band 282 which
secures the second end region of filter body 70 to shaft 284.
Filter body 70 has a proximal mouth region 286 having at least one
drawstring 288 threaded therethrough. In the embodiment
illustrated, drawstring 288 is threaded through proximal mouth
region 286. Shaft 284 has a lumen 290 therethrough. Shaft 284
further includes a port 292 extending from the shaft exterior to
lumen 290. Drawstring 288 extends from proximal mouth region 286
through port 292 and proximally through lumen 290 of shaft 284.
[0117] In use, filter body 70 can be constrained and significantly
radially reduced in profile to fit within a delivery sheath or
other delivery device. In some methods, drawstrings 288 will be
pulled taut and proximal, substantially reducing the profile of
proximal mouth region 286 as well. In one embodiment, filter body
70 is sufficiently outwardly biased and firm so as to not require
the outward biasing force of a loop within proximal mouth region
286. Filter body 70 can be released or distally ejected from the
filter delivery device and allowed to expand radially outward
within the body vessel or conduit to be filtered. In one method,
proximal mouth region is dimensioned to have an unconstrained
diameter greater than the diameter of the vessel region to be
filtered. Filter body 70 preferably has a nominally cylindrical
shape where the majority of the cylinder also has a unconstrained
diameter greater than the diameter of the vessel region to be
filtered. The unconstrained filter body 70 is thus allowed to
expand outwardly against the vessel walls, while still exerting
some force and thereby at least partially anchoring filter to the
vessel walls to the outward expansion force.
[0118] In some filter body embodiments, blood flow is partially or
totally responsible for expanding the filter body against the
vessel wall. As the distal-most region 78 becomes occluded with
filtrate, shaft 284 can be retracted proximally, thereby bringing
previously non-everted exterior filter surface 76 away from the
vessel wall and taking the place of the distal-most region 78. In
this way, unoccluded filter regions can be supplied without
withdrawing the filter device from the patient. When the filter
device has reached its capacity or the procedure is complete,
drawstrings 288 may be used to at least partially close proximal
opening 287. The at least partially closed filter device can be
withdrawn from the patient's body directly or retracted into a
capture device or sheath and then removed from the patient's body.
Alternatively the filter device can be partially retracted into a
capture device or sheath and the combination with partially
unsheathed filter withdrawn from the patients body.
[0119] In another embodiment, drawstrings or tethers 288 are
secured to filter body 70 at different locations about the proximal
mouth region 286. Drawstrings 288 may be disposed at 180 degree,
120 degree, 90 degree, or other substantially equal distant
intervals about proximal mouth region 286. An outwardly biased
stiffening loop may be disposed about proximal mouth region 286 as
well. In some devices, drawstrings 288 are coupled to the proximal
mouth region and/or the proximal loop member. In this embodiment,
another method may be practiced. The same method may be practiced
in other embodiments, not requiring the stiffening proximal
loop.
[0120] In this method, filter body 70 is allowed to expand after
being delivered to a target vessel region to be filtered. The
drawstrings 288 disposed about proximal mouth region 286 can serve
to tether proximal mouth region 286 to shaft 284. The degree of
eversion of filter device 270 can thus be controlled by the
relative movements of drawstrings 288 within lumen 290 and the
position of shaft 284. In one example, to more fully evert filter
device 70 and increase the volume of everted cavity 83, shaft 284
may be proximally retracted while distally advancing drawstrings
288 through lumen 290. In this way, in some methods, the absolute
position of proximal mouth region 286 within the vessel may be
maintained, while proximally retracting distal ring 282 and thereby
increasing the degree of eversion of filter device 70. When the
filtering process is finished, drawstrings 288 may, in some
methods, be used to reduce the proximal profile of proximal opening
287, followed by retracting device 280 from the patient's body. In
some methods, this proximal retraction is carried out by first
retracting device 280 within a filter retrieval device or sheath in
whole or in part. It may be noted that in some devices, such as
those having the drawstrings spaced about the proximal mouth region
and having the proximal mouth region and/or filter body
sufficiently biased to maintain an open shape, it may not be
necessary for the filter body to expand against the enclosing
vessel walls to anchor the filter device to allow control of
everting.
[0121] FIG. 12A illustrates a filtering/occluding device 300.
Device 300 is similar in many respects to device 140 of FIG. 5B and
includes many of the identically numbered elements previously
described. Device 300 includes proximal shaft 102 having a distal
shaft 104 disposed within, where shaft 104 includes a transverse
region 144 which curves distal of proximal ring 126 and extends
transversely away from proximal shaft 102. Transverse region 144 is
included in some embodiments of the filtering/occluding device, but
not others. Filter body 70 includes a filtering portion 304 and an
occluding portion 302. In some devices, occluding portion 302
includes the same mesh materials as filtering region 304, and
further includes an occluding film disposed over or within the
filtering mesh material. In some embodiments, a polymeric film, for
example polyurethane, silicone, latex, polyethylene, and the like
is disposed over or within a wire mesh material forming the
filtering portion 304.
[0122] In device 300, occluding region 302 is disposed distally of
filtering region 304. Occluding region 302 is thus disposed closer
to and approaches filter body second end region 60, while filtering
region 304 is disposed closer to and approaches filter body first
end region 62.
[0123] Filtering/occluding device 300 and most of the other filter
bodies previously discussed may be considered to have a
longitudinal flow channel through the device. A longitudinal flow
channel may be seen entering at proximal opening 112 and continuing
through the filter body interior, exiting through the filtering
region 304. In configurations where the filter body is
substantially completely occupying a vessel interior, flow around
the device, between the device and the vessel walls, may not be
possible. In such situations, the only flow through the device may
be through the interior, with a substantial portion of the flow
being through a proximal opening, such as proximal opening 112 in
device 300. In devices some device configurations filtering region
302 is presented across substantially the entire vessel inside
diameter and across substantially the entire filter device flow
channel. It may be sent that in device 300, by distally extending
shaft 104, occluding region 302 may expand transversely to more
fully occlude a vessel device 300 is inserted within. Device 300
may thus be considered to operate by extending occluding region 302
across a vessel interior to partially, substantially, or totally
occlude the vessel interior.
[0124] FIG. 12B illustrates filtering/occluding device 300, shown
in a filtering configuration rather than an occluding
configuration. Shaft 104, including transverse region 144, has been
proximally retracted relative to the position in FIG. 12A. Filter
body 70 has been more fully everted, bringing filter body material
previously disposed along the side to the distal-most portion and
to the everted cavity interior. The volume of everted cavity 83 may
be seen to be greater, and the length of the cavity greater,
relative to that of FIG. 12A. Occluding region 302 may be seen to
be now lining the interior of everted cavity 83. Distal-most
portion 78 is now occupied by filter material rather than occluding
material. By comparing FIGS. 12A and 12B, it may be sent that
filtering/occluding device 300 may be switched between a filtering
and occluding mode by the advancement and retraction of shaft
104.
[0125] FIG. 13A illustrates another filtering/occluding device 326.
Device 326 is similar in many respects to device 300 of FIGS. 12A
and 12B. In device 326, the relative positions of the occluding
region and filtering region have been changed relative to those of
device 300. In device 320, as illustrated in FIG. 13A, a first
filtering region 324 is disposed near filter body second end region
60, with occluding region 326 disposed between the first filtering
region 324 and filter body first region 62. In the embodiment
illustrated in FIG. 13A, a second filtering region 328 is disposed
between occluding region 326 and filter body first end region 62.
In the configuration shown in FIG. 13A, fluid flow is possible
through proximal opening 112 and continuing through distal-most
region 78, occupied by filtering material in filtering region
324.
[0126] In FIG. 13B shaft 104 and transverse region 144 have been
proximally retracted, thereby more fully everting filter body 70,
and increasing the volume and length of everted cavity 83. It may
be seen that the length of everted cavity 83 is greater in FIG. 13B
than in FIG. 13A. In FIG. 13B, everted surface region 82 is
occupied by filter material in filtering region 324. Distal-most
region 78 is now occupied by occluding material in occluding region
326. By proximally retracting shaft 104, the filtering material
disposed across the vessel cross section has been replaced by the
occluding material disposed across the vessel cross section.
[0127] FIG. 14 illustrates a drug delivery device which can be used
to deliver drugs, therapeutic agents, or diagnostic agents into the
vessel or preferentially to the vessel wall. Agents can include
restenosis inhibitors, thrombolytic agents, growth factors,
biologically active proteins, and the like. Drug delivery device
340 is similar in many respects to the filtering/occluding device
300 of FIG. 12A and includes identical reference numbers for
similarly described elements. In device 340, occluding region 302
may be seen to occupy everted surface region 82. Filtering region
304 may be seen to occupy the non-everted surface region 76 and
distal-most region 78. Filtering region 304 thus faces vessel walls
222. Everted cavity 83 and everted region 82 may be seen to have
been formed, in device 340, using the embodiment discussed with
respect to FIG. 3A. In particular, everted region 82 has been
formed of material heat-set or otherwise biased to form an everted
distal tip when unconstrained. Preferably the everted surface
region 82 will be heat set to be nearly as large as the vessel
inside diameter so as to minimize the blood volume between the
surface region 82 and the surface region 76, thus localizing the
delivered drug in the general vicinity of the vessel wall. In other
embodiments, drug delivery devices similar to device 340 can be
formed not requiring the bias to form an everting distal tip when
unconstrained. Specifically, in some drug delivery devices, the
configuration of FIG. 3B may be more illustrative of the
unconstrained state of the drug delivery distal tip when
unconstrained.
[0128] Infusion of agents through device 340 is indicated in FIG.
14 at 342. In some embodiments a separate drug infusion tube may be
added to infuse the agents. In the embodiment illustrated, an
annular infusion lumen is formed between shaft 104 and shaft or
tube 102, in the lumen between the inner shaft and the outer tube.
Drugs or other agents may thus be injected at a proximal location
in shaft 102, exiting from or near proximal ring 62, but being
substantially blocked by everting region 82 and occluding region
344 from being carried downstream. The agents, however, are free to
contact vessel walls 222 through non-everted surface regions 76
which are occupied by filtering material 304.
[0129] In one method, drug delivery device 340 can be advanced to a
vessel site to be treated, using methods previously described.
These methods can include advancing device 340 over a guide wire
and/or within the distal region of a delivery device or sheath.
Device 340 can be deployed, and allowed to expand radially. In some
methods, device 340 is maintained in a filtering mode until
delivery of the agent is desired. This may be advantageous in the
coronary blood vessels where angina would result from prolonged
maintenance in the occluding mode. Device 340 may be manipulated,
for example, by longitudinally moving shaft 104 to change the
device mode to the occluding mode, as illustrated in FIG. 14. The
agent may then be infused, for example, through shaft 102 and
allowed to contact vessel walls 222. Device 340 may then be
manipulated to assume the filtering mode, allowing blood flow,
followed by repeated occluding.
[0130] The agent delivery step, occluding step, and the filtering
or perfusing step may be repeated as often as necessary. In
coronary applications, this may allow a substantial period of drug
delivery more directly to the vessel walls while allowing
intermittent periods of perfusing blood flow. When agent delivery
is no longer desired, device 340 may be retracted proximally from
the patient's body, for example, by retracting the device into a
recovery catheter or sheath, as previously described.
[0131] FIG. 15A illustrates another filtering/occluding device 360.
Device 360 is similar in some respects to devices 100 and 120
illustrated in FIGS. 4A and 4B. Similar elements are referenced
with reference numerals previously described. Device 360 also
shares some functional and structural aspects with devices 300 and
320 of FIGS. 12A, 12B, 13A, and 13B.
[0132] Filtering/occluding device 360 includes a proximal shaft 102
coupled to the filter body first end region 62. Distal shaft 104 is
coupled to filter body second end region at distal band, bushing,
or ring 64. Filter body 70 may be seen to have an everted distal
cavity 83, a distal-most region 78, and a non-everted surface
region 76, as previously described. Device 360 also includes
proximal opening 112. Device 360 includes an inflatable element,
represented by an inflatable balloon 361. Balloon 361 includes a
balloon envelope 362 extending to a proximal waist 372 and secured
with a securing band or region 365 to shaft 104. Balloon envelope
362 also extends distally to a distal waist 370 for securing or
bonding to distal ring or band 64. Balloon 361 can include an
inflation tube 364 extending through the balloon interior 368 and
having inflation ports 366 therethrough. In some embodiments,
inflation tube 364 is a continuation of shaft 104, where shaft 104
has an inflation lumen therethrough. Balloon envelope 362 can be
formed of balloon envelope material used for inflatable angioplasty
balloons, well known to those skilled in the art. Typical balloon
envelope materials include nylon, polyester, polyethylene, PEBAX,
silicone, polyurethane, latex, and the like and may be oriented,
preferably biaxially, or unoriented.
[0133] In use, device 360 may be advanced to a target site within a
vessel through a delivery sheath or over a guide wire. Shaft 104,
for example, may include a guide wire lumen therethrough. Rapid
exchange embodiments having a separate guide wire tube and lumen
extending over only over a distal region are also within the scope
of the invention. When disposed at the target vessel region,
balloon 362 can be inflated by providing inflation fluid through
shaft 104, through inflation ports 362 and into balloon interior
368. With balloon 362 inflated, the flow channel or path through
the vessel is completely or substantially blocked. In this mode,
particulate flow past balloon 362 is essentially precluded. The
particulate mater or filtrate may be allowed to gather proximal of
inflated balloon 362 and be aspirated, removing most or all of the
matter blocked by inflated balloon 362. When perfusing fluid flow
or blood flow is desired, balloon 362 can be deflated and collapsed
by removing the inflation fluid, and in some methods, pulling a
vacuum on balloon interior on 368 through shaft 104. With balloon
362 collapsed, a perfusing fluid flow through device 360 is once
again established. Particulates or filtrate not removed during an
aspiration step may still be captured by filter body 70. In this
way, some methods may capture much of the filtrate using the
occluding, inflated balloon followed by aspiration, follow by
reliance on the mesh filter material of filter body 70 to capture
material which was not removed during aspiration and/or flows into
filter body 70 after the aspiration step. As filtrate is captured
near the distal-most region 78, filter body 70 may be further
everted by proximally retracting shaft 104, as previously discussed
with respect to other devices. After the filtering step or steps
are complete, device 360 may be removed from the patient's body. In
some methods, device 360 is removing by retracting the device
proximally into a capture sheath or other device. In one method,
shaft 104 may be proximally retracted during or after the filtering
step or steps. Balloon 362 can be partially or fully inflated to
prevent any loss of filtrate through proximal opening 112 during
some or all of the retraction steps.
[0134] Filtering/occluding devices for example devices 300, 320,
and 360, may be used in many applications. The filtering/occluding
device may be advanced distally past thrombosed or stenosed regions
to be treated. The device may be maintained in the filtering mode
during periods in which only a small amount of filtrate material is
expected to be carried downstream to the filtering/occluding
device. When heavier material flow is expected, such as during
stent expansion or balloon predilatation, the device can be
manipulated into the occluding mode, ensuring almost total blockage
of particulate matter from downstream travel. The material may then
be aspirated, and the device manipulated back to the filtering
mode.
[0135] In one use, the filtering/occluding or perfusing/occluding
device may be used in the filtering or perfusing mode during
radiopaque dye injection, and used in an occlusive mode for the
remainder of the procedure. In another use of such
filtering/occluding devices, the devices may be used primarily in
either the occluding or filtering mode, depending on the judgment
of the treating physician. In such use, a single
filtering/occluding device may be provided for both primarily
filtering or occluding uses, and physicians may choose to utilize
the device for primarily the occluding or filtering modes. A single
device may thus be carried which can be put to either filtering or
occluding use, not requiring the stocking of both devices. The
choice of a filtering or occluding device may thus be postponed
well past the point of purchase and even past the point of
insertion into the patient. The choice between an occluding device
or filtering device may thus be made during treatment, after the
filtering/occluding device has been deployed, for example,
downstream of a vessel blockage to be removed.
[0136] FIG. 16 illustrates a thombectomy device 360, similar in
many aspects to filter device 140 illustrated in FIG. 5B.
Thombectomy device 360 includes shaft 102 coupled to filter body 70
and having distal shaft 104 slidably disposed within shaft 102.
Thombectomy device 360 may be further understood by reading the
description of device 140, previously described.
[0137] Thombectomy device 360 has a proximal opening 112 and a
proximal loop 364. Proximal loop 364 is preferably sufficiently
rigid and can be biased to expand radially outward and to maintain
a sufficiently rigid shape when encountering a thrombus such as
thrombus 362. In some embodiments, proximal loop 364 has a
proximally leading edge sufficiently narrow or sharp to cut through
or dislodge thrombus 362. In some embodiments, proximal loop 364 is
formed of Nitinol wire biased to firmly engage vessel wall 222.
Proximal loop 364 may be threaded through filter body 70 at
location 365 indicated near vessel wall 222, opposite shaft 102. In
other embodiments, proximal loop 364 may be threaded through the
proximal mouth region of filter body 70 in numerous locations about
the mouth region. Thombectomy device 360 may be deployed downstream
of thrombus 362 using methods previously discussed, including dye
catheters, and delivery tubes.
[0138] FIG. 17 illustrates thombectomy device 360 after proximal
loop 364 has been pulled through thrombus 362. While shaft 102 has
been proximally retracted, distal shaft 104 has been distally
advanced relative to the retracting proximal shaft 102. The degree
of eversion of filter body 70 may be seen to be greater in FIG. 16
than in FIG. 17. Filter body 70 has been elongated, during the
capture of thrombus 362.
[0139] FIG. 18 illustrates thrombus 362, captured within device
360, with device 360 being retracted proximally into a capture
device or tube 366 having a lumen 368 therethrough. As previously
discussed with respect to other embodiments, proximal loop 364 may
be at least partially closed prior to or during the proximal
retraction step. The proximal mouth can be substantially closed by
retraction into tube 366, and once this occurs thrombus 362 will be
entirely captive within device 360.
[0140] FIG. 19 illustrates thombectomy device 360 after being
proximally retracted within capture device 366. Capture device 366,
thombectomy device 360, and thrombus 362 may be proximally
retracted from the patient.
[0141] FIG. 20A illustrates filter body 70 having a bellows shape.
While filter body 380 may be used in conjunction with any of the
previously discussed embodiments, one preferred use is in forming
the filter body of thombectomy devices, such as thombectomy device
360. The filter body used for thrombectomy devices can be formed of
a polymeric film rather than a porous mesh in some devices, or by a
combination of the mesh with a film. Device 380 may be seen to have
a bellows configuration, having the filter body length
substantially foreshortened during proximal retraction of shaft
104. The excess filter body material which will ultimately be used
to extend the length of the filter may be bunched or folded upon
itself along regions of preferential folding 382. Regions of
preferential folding 382 may be formed by wire hoops, heat set
regions, and any of a number of shape memory materials commonly
known to those skilled in the art. Regions of preferential folding
may also be formed by ribs set into the filter material. Regions of
preferential folding 382 may be seen to form a series of valleys
364 separated by peaks 386. FIG. 20B illustrates device 380 in an
elongated configuration. Device 380 can provide a high ratio
between the elongated length and the shortened length. The bellows
shape can provide a high ratio between filled length and deployed
length.
[0142] Thrombectomy device 380 can be deployed through a small
catheter distal to a thrombus or other blockage material. The
deployed shape is preferably the shortest shape so as to minimize
the length needed for deployment. The device may be delivered
within a catheter in an elongated shape and then deployed out the
end of the catheter by pushing on shaft 102 while only slightly
retracting the catheter so as to deploy the maximally shortened
length immediately distal to the deployment catheter. Typically the
catheter is then removed. Shaft 102 can be used to draw filter body
70 through the thrombus, with a proximal loop dislodging the
thrombus from the vessel wall, and the thrombus entering and
lengthening the filter body. The thrombus filled filter body can be
partially retracted into a recovery catheter to close the proximal
loop and proximal opening. The filter body can be either retracted
further into the catheter or the recovery catheter retracted from
the patient coupled to the partially retracted filter body. In one
embodiment, the thrombectomy device of FIGS. 20A and 20B has an
everted distal region. In another embodiment, the thrombectomy
device of FIGS. 20A and 20B does not have an everted distal
region.
[0143] FIG. 21A illustrates a proximal handle portion 400 including
an outer tube 402 and an inner shaft 408. Proximal handle portion
400 can be used in embodiments having a shaft extending distally
from a tube, such as the example of FIG. 4C. Outer tube 402
includes a proximal region 404 having a proximal port 406 having
shaft 408 extending proximally from the tube. Shaft 408 is
preferably closely fit and slidably disposed within tube 402.
[0144] FIG. 21B illustrates a proximal handle portion 410 which can
be used in devices having tethers or drawstrings, for example the
device illustrated in FIG. 11. Proximal handle portion 410 includes
an outer tube 412 having a proximal region 414 and a lumen 413
within. A handle 416 can be slidably disposed within tube 412 and
have tethers 417 attached to the handle. Handle 416 can have a
proximal region 418 having an outer diameter indicated at 411,
where the outer diameter can be larger than the inside diameter of
the tube, and can be about 0.014 inch or larger in some
embodiments. Handle 416 can also have a stepped down diameter
portion 419 adapted to slidable fit within tube 412. The tethers
can be proximally retracted by proximally retracting handle
416.
[0145] FIG. 21C illustrates a proximal handle portion 420 which can
be used in devices having tethers or drawstrings, for example thc
device illustrated in FIG. 11. Handle portion 420 can have a tube
422 having a round portion 424, a more proximal cut-away portion
425, and a proximal end 423. Tethers or drawstrings 436 can be
disposed within tube 422 and extend proximally from an opening 434
disposed between an insert 426 and tube round portion 424. The
length of opening 434 is indicated at 432, and is preferably long
enough to allow the tethers to easily egress the tube. An insert
426 can be disposed within tube 422, and can be within cutaway
portion 425. Insert 425 can be formed of an elastomeric material,
may be formed within and bonded to the tube, and have a slit 428
formed into the insert. Slit 428 can be used to lock down the
tethers into the slit while allowing the tethers to be pulled free
of the insert and proximally retracted. The outer diameter of tube
422 is indicated at 430 and can be about 0.014 inch in one
embodiment. The small inside diameter and long length, nominally
145 cm, of the tube will substantially reduce or preclude any blood
loss through opening 434.
[0146] FIG. 21D illustrates a proximal handle portion 440 including
a tube 442 which can be used in devices having a drug delivery
lumen or an inflation lumen disposed within the tube. A tee
connector 441 having sidearms 452, a lumen 454, and Tuohy-Borst
fittings 456 and 458 is disposed about tube 442. Tee connector 441
can include an injection port 462 which can be used to inject drugs
into the connector and tube. Tube 442 can have a proximal port 446
having an inner shaft or elongate member 448 extending proximally
from the tube, with the shaft extending further proximally through
proximal fitting or seal 458 through a proximal port 460,
terminating in a shaft proximal region 450. Shaft 448 can thus
slide within tube 442. In some embodiments, port 446 is the
proximal port for an annular lumen formed between tube 442 and
shaft 448.
[0147] FIGS. 21E and 21F illustrate a proximal handle portion 480
including an outer tube 482 and an inner shaft 481. Proximal handle
portion 480 can be used in embodiments having an inflatable
balloon, such as the example of FIGS. 15A and 15B, as well as other
examples of the invention. Outer tube 482 includes a proximal
region 484 having a proximal port 487 with shaft 481 being
proximally accessible for manipulation from outside of the tube. A
handle 485 may be seen to have a large outer diameter portion 486,
a stepped down portion 488 slidably disposed within tube 482, which
is coupled to inner shaft portion 489. Tube 482 can have a port or
microhole 485 in communication with tube lumen 483. In the
configuration of FIG. 21E, microhole 485 is blocked by handle
stepped down portion 488 In the configuration of FIG. 21F,
microhole 485 is not blocked by the handle, which has been
proximally retracted.
[0148] The porous mesh filter bodies of the present invention can
be formed of strands, ribbons, or wire, where the materials forming
the strands, ribbons, or wires can be metallic or polymeric.
Non-limiting examples of such materials include Nitinol, stainless
steel, Elgiloy, spring steel, beryllium copper, nylon, PEEK, PET,
liquid crystals, polyimide, and shape memory alloys and polymers
generally. Elastomeric polymers can be also be used to form the
strands and filter bodies. The elastomeric polymers can be formed,
shaped, or post processed to achieve the desired shape. Examples of
elastomeric polymers include butyl rubber, natural rubber, latex,
and polyurethanes. The strands or wires can have circular, square,
rectangular, or irregular cross-sectional shapes. In one filter,
the strands or wires have an outer diameter between about 0.001
inch and 0.010 inch. The mesh can be any mesh having suitable
porosity for the intended use, for example, for allowing perfusing
blood flow while capturing emboli. Examples meshes include braids,
knits, interlocking rings or polygons, weaves, helically wound
patterns, and nonwoven meshes formed from chopped strand fibers.
The filters can include radiopaque markers, for example, platinum
wires disposed in the mesh or radiopaque coatings applied to the
strands, or the strands can be composites of radiopaque and
radiolucent materials disposed for example in a coaxial
relationship.
[0149] The mesh filter bodies may be made using methods similar to
those described in U.S. Pat. No. 6,325,815 and PCT Publication No.
WO 96/01951, both herein incorporated by reference. In one method,
a one-layer braided Nitinol mesh cylinder is threaded through the
lumen of a forming cylinder, folded over the forming cylinder
rounded nose, folded back on the outside of the forming cylinder,
and heat set. This results in a pre-stressed braid that can easily
recoil in a similar manner to a spring. A dense braid, having a
high number of picks per inch (PPI) is preferred. One filter
embodiment has between about 50 and 400 PPI.
[0150] Some meshes are selected to have an average pore size large
enough to allow perfusing blood flow while small enough to capture
emboli. Various meshes have average pore sizes of at least about
20, 50, and 100 microns. The meshes used for the
perfusing/occluding embodiments of the invention may have larger
average pore size, in embodiments intended for only perfusing and
occluding rather than filtering and occluding. Some embodiments of
the drug infusion device, previously described, can include a large
pore size region intend to provide structure and allow drug passage
rather than providing significant filtration capture capacity for
emboli.
[0151] The curved or transversely extending shaft distal regions
found within some filter bodies can be formed of Nitinol, heat set
to assume a bent, curved, or S-shape when unconstrained. In some
methods, the shaft is formed of Nitinol wire, heat set at about 600
degrees C.
[0152] The dimensions of the various everted filter devices may
vary, depending on the intended application. The dimension ranges
required are well known to those skilled in the art. The device
dimensions may be dictated by the expected vessel inner diameters,
the distance from the point of insertion to the vessel region to be
treated, and the dimensions of other instruments to be used
concurrently in the same vessel. In one example, filters intended
for use in filtering carotid arteries are expected to be larger
than those for coronary artery applications, which are likely
larger than those for use in the cerebral arteries.
[0153] Some everted filter devices have elongate member lengths
ranging from about 50 cm to about 320 cm. In one group of
embodiments, the outer diameter of tethers range from about 0.001
inch to about 0.005 inch, the outer diameter of solid shafts range
from about 0.008 inch to about 0.035 inch, and the outer diameter
of tubes range from about 0.010 inch to about 0.035 inch. In some
filter bodies, in the fully elongated state the length is between
about 10 mm and 50 cm, while the outer diameter is between about 2
mm and 35 mm. In a fully radially expanded and shortened state,
some filter bodies can have a length of between about 2 mm and 10
mm, while the outer diameter can be between about 3 mm and 38 mm.
The proximal opening size may have an average width of between
about 1 mm and 35 mm. In some filters, the average pore size can
increase by about 5000 percent from the most compressed to the most
expanded state. As used herein, the term "pore size" refers to the
diameter of the largest sphere that will fit through the pore. A
pore can become elongated as the mesh is elongated. The elongated
pore may have a very large width and a very small height, therefore
having a very small pore size.
* * * * *