U.S. patent application number 10/113724 was filed with the patent office on 2003-10-02 for endoluminal devices, embolic filters, methods of manufacture and use.
Invention is credited to Cully, Edward H., Vonesh, Michael J..
Application Number | 20030187495 10/113724 |
Document ID | / |
Family ID | 28453667 |
Filed Date | 2003-10-02 |
United States Patent
Application |
20030187495 |
Kind Code |
A1 |
Cully, Edward H. ; et
al. |
October 2, 2003 |
Endoluminal devices, embolic filters, methods of manufacture and
use
Abstract
A seamless, self-expanding implantable device having a low
profile is disclosed along with methods of making and using the
same. The implantable device includes a frame cut out of a single
piece of material that is formed into a three-dimensional shape.
The implantable device may comprise an embolic filter, stent, or
other implantable structure. The present invention also allows
complicated frame structures to be easily formed from planar sheets
of starting material, such as through laser cutting, stamping,
photo-etching, or other cutting techniques.
Inventors: |
Cully, Edward H.;
(Flagstaff, AZ) ; Vonesh, Michael J.; (Flagstaff,
AZ) |
Correspondence
Address: |
David J. Johns
W. L. Gore & Associates, Inc.
551 Paper Mill Road
P.O. Box 9206
Newark
DE
19714-9206
US
|
Family ID: |
28453667 |
Appl. No.: |
10/113724 |
Filed: |
April 1, 2002 |
Current U.S.
Class: |
623/1.15 ;
606/200; 623/1.34 |
Current CPC
Class: |
A61F 2002/016 20130101;
A61F 2230/005 20130101; A61F 2230/0069 20130101; A61F 2/0108
20200501; A61F 2230/0067 20130101; A61F 2230/0093 20130101; A61F
2230/0015 20130101; A61F 2230/008 20130101; A61F 2230/0076
20130101; A61F 2/0105 20200501; A61F 2/91 20130101; A61F 2002/018
20130101; A61F 2/013 20130101; A61F 2230/0091 20130101; A61B
17/12109 20130101; A61F 2230/0006 20130101 |
Class at
Publication: |
623/1.15 ;
623/1.34; 606/200 |
International
Class: |
A61F 002/06; A61M
029/00 |
Claims
What is claimed is:
1. A filter comprising: a seamless frame having a proximal end and
a longitudinal axis, said frame having a seamless support member
circumscribing said axis and distally spaced from said proximal
end, said support member having at least one attachment strut
seamlessly extending therefrom and terminating at said proximal
end, and a filter media having an open, proximal end cooperating
with said support member and a closed end extending distally away
from said open end and defining the end of said filter.
2. The filter according to claim 1 further including at least one
filter strut seamlessly extending distally from support member and
having a mid-point that is distally spaced from said support
member, said at least one filter strut engaging and supporting said
filter media.
3. The filter according to claim 1, wherein said at least one
attachment strut comprises a plurality of attachment struts each
seamlessly extending from said support member and terminating at
said proximal end.
4. The filter according to claim 2, wherein said at least one
filter strut comprises a plurality of filter struts seamlessly
extending distally away from said support member.
5. The filter according to claim 1, further including a plurality
of filter struts seamlessly extending distally away from said
support member.
6. The filter according to claim 2, wherein there are at least two
filter struts.
7. The filter according to claim 2, wherein there are at least
three filter struts.
8. The filter according to claim 3, wherein there are between 4 and
12 filter struts.
9. The filter according to claim 3, wherein there are at least 6
filter struts.
10. The filter according to claim 3, wherein there is between 6 and
18 filter struts.
11. The filter according to claim 1, wherein said at least one
attachment strut and said support member are respectively formed
from different portions of a helically configured frame having
multiple turns, with one turn forming said support member.
12. An endovascular device comprising: a seamless frame having a
proximal end, a distal end and a longitudinal axis extending
therebetween, said frame having a seamless support member
circumscribing said axis and located between said proximal and
distal ends, a first set of struts extending seamlessly from said
support member towards said proximal end and a second set of struts
extending seamlessly from said support member towards said distal
end.
13. The device of claim 12, wherein at least one strut of said
first and second struts sets includes radiopaque markers.
14. The filter according to claim 1, wherein said filter media
includes a plurality of filter media layers.
15. The filter according to claim 14, wherein there are two filter
media layers which are separated from one another.
16. The filter according to claims 1, wherein the filter media
includes a pharmacological agent.
17. The filter according to claim 14, wherein at least one of said
layers includes a pharmacological agent.
18. The filter according to claim 15, wherein a pharmacological
agent is located in a space between the separated filter media
layers.
19. The filter according to claim 14, wherein each of said
plurality of filter media layers possesses different physical or
chemical properties.
20. An endovascular device comprising: a seamless frame having a
proximal end, a seamless circular support member having a
proximally and seamlessly extending attachment strut terminating in
a proximal connecting end, and a biocompatible, open ended tubular
member having a proximal end attached to said support member.
21. The device according to claim 20, wherein said tubular member
has a symmetrically tapered terminal end similar to a windsock.
22. The device according to claim 20, wherein said tubular member
is an endovascular graft.
23. The filter according to claim 1, wherein said filter media is
sombrero shaped.
24. The filter according to claim 1, wherein said filter media is
conically shaped.
25. The filter according to claim 1, where said support member and
said at least one attachment strut is formed from a biocompatible
material.
26. The filter according to claim 25, wherein the biocompatible
material is self-expanding.
27. The filter according to claim 25, wherein the biocompatible
material is a polymer.
28. A method of constructing a uni-body, self-expanding filter
frame comprising: extracting a substantially two-dimensional filter
frame pattern from common planar sheet of precursor material by
cutting; configuring said two-dimensional pattern into a
three-dimensional configuration; and thermally annealing said
three-dimensional configuration.
29. The method according to claim 28, wherein said pattern includes
attachment struts and support struts.
30. The method according to claim 28, wherein said pattern includes
attachment struts, support struts and filter support struts.
31. The method of claim 29, wherein the precursor material is a
shape memory alloy.
32. The method according to claim 28, wherein the two-dimensional
filter frame has at least one closed cell, the at least one cell
including an area that has a circumference defined by a seamlessly
continuous ribbon or strut of the same precursor material.
33. The method according to claim 28, further comprising attaching
a filter media to the filter frame before or after annealing.
34. The method according to claim 33, wherein the filter media
includes a pharmacological agent.
35. The method of claim 28, wherein a portion of said anneal frame
is positioned between two layers or portions thereof of filter
media and the layers assembly laminated together.
36. A method of attaching a biocompatible, permeable filter media
to a three dimensional filter frame comprising: providing a
three-dimensional filter frame; deforming the three-dimensional
frame into a substantially planar, two dimensional configuration;
and adhering at least one layer of filter media on the frame.
37. A method of assembly a filter comprising providing a conical
filter element; providing a three-dimensional seamless filter
frame; and laminating said filter element and frame together.
38. The filter according to claim 3, wherein said plurality of
attachment struts include at least one integral articulation
segment.
39. The filter according to claim 38, wherein said at least one
integral articulation segment includes a geometrically altered
cross-sectional attachment strut section.
40. The filter according to claim 38, wherein said at least one
integral articulation segment includes a zig-zag or undulating
configuration.
41. The filter according to claim 2, wherein at least one filter
strut includes a radiopaque marker.
42. The device according to claim 21, wherein said tubular member
has an asymmetrically tapered terminal end.
43. The filter according to claim 1, wherein said filter media is
asymmetrically cone shaped.
44. A method of constructing a uni-body, frame comprising:
extracting a substantially two-dimensional plastically deformable
frame pattern from a common planar sheet of plastically deformable
material by cutting; configuring said two-dimensional pattern into
a three-dimensional configuration; and thermally treating said
three-dimensional configuration.
45. A method of constructing a uni-body, self-expanding frame
comprising: extracting a substantially two-dimensional frame
pattern from a common planar sheet of a shape-memory alloy,
self-expanding material by cutting; configuring said
two-dimensional pattern into a three-dimensional configuration; and
thermally annealing said three-dimensional configuration.
46. The method according to claim 29, wherein said attachment
struts have at least one articulation region.
47. The method according to claim 30, wherein said filter struts
are adapted to incorporate a radio-opaque marker without adding
thickness.
48. The method according to claim 44, wherein said pattern includes
attachment struts and/or support struts.
49. The method according to claim 44, wherein said pattern includes
attachment struts, and/or support struts and/or filter support
struts.
50. The method according to claim 4-5, wherein said pattern
includes attachment struts and/or support struts.
51. The method according to claim 45, wherein said pattern includes
attachment struts and/or support struts and/or filter support
struts.
52. The method according to claim 49, wherein any of said struts
are adapted to incorporate a radio-opaque marker without adding
thickness.
53. The method according to claim 51, wherein any of said struts
are adapted to incorporate a radio-opaque marker without adding
thickness.
54. The filter according to claim 3, wherein said at least one
attachment strut includes metallurgical articulation segments.
55. The filter according to claim 3, wherein said at least one
attachment strut includes different articulation segments.
56. The filter according to claim 1, wherein said at least one
attachment strut includes at least one seamless and integral
articulation segment.
57. The filter according to claim 56, wherein said at least one
seamless and integral articulation segment includes a geometrically
altered cross-sectional attachment strut section.
58. The filter according to claim 1, wherein said at least one
attachment strut includes at least one seamless and integral
metallurgical articulation segment.
59. A filter comprising: a seamless frame having a proximal end and
a longitudinal axis, said frame having a seamless support member
circumscribing said axis and distally spaced from said proximal
end, said support member having at least one attachment strut
seamlessly extending therefrom and terminating at said proximal
end, and at least one filter media having an open, proximal end
cooperating with said support member and a closed end.
60. A device comprising: a seamless frame having a proximal end, a
distal end and a longitudinal axis extending therebetween, said
frame having at least one seamless support member circumscribing
said axis and located between said proximal and distal ends, at
least one of a first set of struts extending seamlessly from said
support member towards said proximal end and at least one of a
second set of struts extending seamlessly from said support member
towards said distal end.
61. The device according to claim 60, wherein a plurality of
seamless support members circumscribe said axis.
62. The device according to claim 60, wherein at least one of said
struts of said first and second sets of struts and said at least
one support member includes at least one of an integral
articulation member and a radio-opaque marker.
63. The device according to claim 60, further including at least
one seamless and integral articulation segment.
64. The device according to claim 62, further including a plurality
of circumscribing members, and at least one integral articulation
segment, one of which seamlessly interconnects said members.
65. An endovascular device comprising: a seamless frame having open
proximal and distal ends and a plurality of seamless integral
struts formed from a common precursor material, at least some of
said struts being seamlessly interconnected with one another to
define a plurality of closed cells, and at least one of said
plurality of seamless struts optionally having at least one
articulation segment and/or radiopaque marker.
66. The device according to claim 65, wherein same frame is a
tubular stent.
67. The device according to claim 65, wherein said frame includes
integral articulation segments.
68. The device according to claim 65, wherein said frame includes
radiopaque markers.
69. The device according to claim 65, wherein said frame includes
integral articulation segments and radiopaque markers.
70. The filter according to claim 5, wherein said distally
extending filter struts terminate at a common seamless distal
end.
71. The filter according to claim 12, wherein said distally
extending filter struts terminate at a common seamless distal end.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to seamless endoluminal
devices including frame patterns for filters, their manufacture and
use in the filtration and/or removal of embolic matter from fluids
flowing in tubular body lumens including, but not limited to: blood
flow in arteries and veins; airflow within the respiratory tract;
and the flow of urine in the urinary tract. The seamless filter of
the present invention may be self-expanding, is deployable via a
guidewire-based system and has a low profile.
BACKGROUND OF THE INVENTION
[0002] Embolic protection is a concept of growing clinical
importance directed at reducing the risk of embolic complications
associated with interventional (i.e., transcatheter) and surgical
procedures. In therapeutic vascular procedures, liberation of
embolic debris (e.g., thrombus, clot, atheromatous plaque, etc.)
can obstruct perfusion of the downstream vasculature, resulting in
cellular ischemia and/or death. The therapeutic vascular procedures
most commonly associated with adverse embolic complications
include: carotid angioplasty with or without adjunctive stent
placement and revascularization of degenerated saphenous vein
grafts. Additionally, percutaneous transluminal coronary
angioplasty (PTCA) with or without adjunctive stent placement,
surgical coronary artery by-pass grafting, percutaneous renal
artery revascularization, and endovascular aortic aneurysm repair
have also been associated with complications attributable to
atheromatous embolization. Intraoperative capture and removal of
embolic debris, consequently, may improve patient outcomes by
reducing the incidence of embolic complications.
[0003] The treatment of stenoses of the carotid bifurcation
provides a good example of the emerging role of adjuvant embolic
protection. Cerebrovascular stroke is a principle source of
disability among adults, and is typically associated with stenoses
of the carotid bifurcation. The current incidence of
cerebrovascular stroke in Europe and the United States is about 200
per 100,000 population per annum (Bamford, Oxfordshire community
stroke project. Incidence of stroke in Oxfordshire. First year's
experience of a community stroke register. BMJ 287: 713-717, 1983;
Robins, The national survey of stroke: the National Institute of
Neurological and Communicative Disorders and Stroke. Office of
Biometry and Field Studies Report. Chapter 4. Incidence. Stroke 12
(Suppl. 1): 1-57, 1981). Approximately half of the patients
suffering ischemic stroke have carotid artery stenoses (Hankey,
Investigation and imaging strategies in acute stroke and TIAs.
Hospital Update 107-124, 1992). Controlled studies have shown that
the surgical procedure carotid endarterectomy (CEA) can reduce the
incidence of stroke in patients compared to medical therapy with
minimal perioperative complications (<6% for symptomatic
patients with stenoses >70% [NASCET, Beneficial effect of
carotid endarterectomy in symptomatic patients with high grade
stenoses. NEJM 325: 445-453, 1991] and <3% for asymptomatic
patients with 60% stenoses [ACAS, Endarterectomy for asymptomatic
carotid artery stenosis. JAMA 273: 1321-1461, 1995]). These results
provide convincing evidence of the benefit of treating carotid
stenoses. Surgery, however, does have several limitations,
including: increased mortality in patients with significant
coronary disease (18%), restriction to the cervical portion of the
extra-cranial vasculature, a predeliction for cranial palsies
(7.6%-27%), and restenosis (5%-19%; Yadav, Elective stenting of the
extracranial carotid arteries. Circulation 95: 376381, 1997).
[0004] Carotid angioplasty and stenting have been advocated as
potential alternatives to CEA. Percutaneous techniques have the
potential to be less traumatic, less expensive, viable in the
non-cervical extracranial vasculature, and amenable to patients
whom might otherwise be inoperable (Yadav, Elective stenting of the
extracranial carotid arteries. Circulation 95: 376-381, 1997).
Despite the potential benefits of this approach, emboli liberated
during trans-catheter carotid intervention can place the patient at
risk of stroke. Emboli can be generated during initial accessing of
the lesion, balloon pre-dilatation of the stenosis, and/or during
stent deployment. Additionally, prolapse of atheromatous material
through the interstices of the stent can embolize after the
completion of the procedure.
[0005] The fear of dislodging an embolus from an atherosclerotic
plaque has tempered the application of angioplasty and endovascular
stenting to the supraaortic arteries and, particularly, to the
carotid bifurcation (Theron, New triple coaxial catheter system for
carotid angioplasty with cerebral protection. AJNR 11: 869-874,
1990). This concern is warranted due to the significant morbidity
and/or mortality that such an event might produce. While the
incidence of stroke may be at an acceptable level for the highly
skilled practitioner, it is likely to increase as the procedure is
performed by less experienced clinicians.
[0006] Embolic protection devices typically act as an intervening
barrier between the source of the clot or plaque and the downstream
vasculature. In order to address the issue of distal embolization,
numerous apparatus have been developed and numerous methods of
embolic protection have been used adjunctively with percutaneous
interventional procedures. These techniques, although varied, have
a number of desirable features including: intraluminal delivery,
flexibility, trackability, small delivery profile to allow crossing
of stenotic lesions, dimensional compatibility with conventional
interventional implements, ability to minimize flow perturbations,
thromboresistance, conformability of the barrier to the entire
luminal cross-section (even if irregular), and a means of safely
removing the embolic filter and trapped particulates.
[0007] For example, occlusion balloon techniques have been taught
by the prior art and involve devices in which blood flow to the
vasculature distal to the lesion is blocked by the inflation of an
occlusive balloon positioned downstream to the site of
intervention. Following therapy, the intraluminal compartment
between the lesion site and the occlusion balloon is aspirated to
evacuate any thrombus or atheromatous debris that may have been
liberated during the interventional procedure. These techniques are
described in Theron, New triple coaxial catheter system for carotid
angioplasty with cerebral protection. AJNR 11: 869-874, 1990, and
Theron, Carotid artery stenosis: Treatment with protected balloon
angioplasty and stent placement. Radiology 201: 627-636, 1996, and
are commercially embodied in the PercuSurge Guardwire Plus.TM.
Temporary Occlusion and Aspiration System (Medtronic AVE). The
principle drawback of occlusion balloon techniques stem from the
fact that during actuation distal blood flow is completely
inhibited, which can result in ischemic pain, distal is
stasis/thrombosis, and difficulties with fluoroscopic visualization
due to contrast wash-out through the treated vascular segment.
[0008] Another prior system combines a therapeutic catheter (e.g.,
angioplasty balloon) and integral distal embolic filter. By
incorporating a porous filter or embolus barrier at the distal end
of a catheter, such as an angioplasty balloon catheter,
particulates dislodged during an interventional procedure can be
trapped and removed by the same therapeutic device responsible for
the embolization. One known device includes a collapsible filter
device positioned distal to a dilating balloon on the end of the
balloon catheter. The filter comprises a plurality of resilient
ribs secured to the circumference of the catheter that extend
axially toward the dilating balloon. Filter material is secured to
and between the ribs. The filter deploys as a filter balloon is
inflated to form a cup-shaped trap. The filter, however, does not
necessarily seal around the interior vessel wall. Thus, particles
can pass between the filter and the vessel wall. The device also
presents a large profile during positioning and is difficult to
construct.
[0009] The prior art has also provided systems that combine a
guidewire and an embolic filter. The filters are incorporated
directly into the distal end of a guidewire system for
intravascular blood filtration. Given the current trends in both
surgical and interventional practice, these devices are potentially
the most versatile in their potential applications. These systems
are typified by a filter frame that is attached to a guidewire that
mechanically supports a porous filter element. The filter frame may
include radially oriented struts, one or more circular hoops, or a
pre-shaped basket configuration that deploys in the vessel. The
filter element typically includes a polymeric mesh net, which is
attached in whole or in part to the filter frame and/or guidewire.
In operation, blood flowing through the vessel is forced through
the mesh filter element thereby capturing embolic material in the
filter.
[0010] Early devices of this type include a removable intravascular
filter mounted on a hollow guidewire for entrapping and retaining
emboli. The filter is deployable by manipulation of an actuating
wire that extends from the filter into and through the hollow tube
and out the proximal end. During positioning within a vessel, the
filter material is not fully constrained so that, as the device is
positioned through and past a clot, the filter material can
potentially snag clot material creating freely floating emboli,
prior to deployment.
[0011] In another prior art system an emboli capture device is
mounted on the distal end of a guidewire. The filter material is
coupled to a distal portion of the guidewire and is expanded across
the lumen of a vessel by a fluid activated expandable member in
communication with a lumen running the length of the guidewire.
During positioning, as the device is passed through and beyond the
clot, filter material may interact with the clot to produce emboli.
This device may also be difficult to manufacture.
[0012] Another prior art device is adapted for deployment in a body
vessel for collecting floating debris and emboli in a filter that
includes a collapsible proximally tapered frame for operably
supporting the filter between a collapsed insertion profile and an
expanded deployment profile. The tapered collapsible frame includes
a mouth that is sized to extend to the walls of the body vessel in
the expanded deployed profile to seal the filter relative to the
body vessel for collecting debris floating in the body vessel.
[0013] A further example of an embolic filter system involves a
filter material fixed to cables or spines of a central guidewire. A
movable core or fibers inside the guidewire can be utilized to
transition the cables or spines from approximately parallel to the
guidewire to approximately perpendicular to the guidewire. The
filter, however, may not seal around the interior vessel wall.
Thus, particles can pass between the filter and the entire vessel
wall. This umbrella-type device is shallow when deployed so that,
as it is being closed for removal, particles have the potential to
escape.
[0014] Other disadvantages associated with the predicate devices
are that the steerability of the guidewire may be altered as
compared to the conventional guidewires due to the presence and
size of the filter. The guidewire, for example, may bend, kink,
and/or loop around in the vessel, making insertion of the filter
through a complex vascular lesion difficult. Also, delivery of such
devices in a low-profile pre-deployment configuration can be
difficult. Further, some devices include complex and cumbersome
actuation mechanisms. Also, retrieving such capture devices after
they have captured emboli may be difficult. Further, when deployed
in curved segments, the interaction of the guidewire and/or tether
elements can deform the filter frame in such a way as to limit
apposition to the host vessel wall, thereby allowing potential
channels for passage of embolic debris. Also, the filter media of
the prior art maintains a pore diameter of approximately 80 to 120
microns. It is desirable to minimize the pore size without
adversely perturbing blood flow or being prone to clogging.
[0015] Current filter designs suffer from numerous disadvantages
due to their construction. A typical wire filter is formed by
manipulating multiple wires together through welding or some other
form of attachment. After the wire frame is constructed, it is
formed into the desired shape and a filter element is affixed onto
the wire cage. A typical wire frame constructed in this manner is
subject to a limited range of manipulation after the wires are
adhered, since the welds or attachment areas are at an increased
risk of failure due to the physical constraints of the welds
themselves. A wire pair is more inclined to fracture at the weakest
point, typically, a wire frame, composed of numerous wire pairs,
will separate at the weld before separating in the length of the
wire. Additionally, the welding of metal involves the application
of increased heat to join a wire pair and a risk exists of the
mesh, formed by the pairs, dripping or otherwise malforming due to
the proclivity of metal to run before cooling.
[0016] A further disadvantage to a typical wire filter is that the
filter element is difficult to apply to the frame since the filter
is normally applied as a sock, tube, or other such shape. The
typical wire frame is formed by welding and bending into the
desired shape. The filter is then affixed onto the shaped wire
frame by pulling the formed filter over the shaped wire frame. An
additional problem evident in this construction is that the filter
element could be abraded by a protrusion formed by a weld in a wire
pair. Such an abrasion could form a weakness or a tear in the
filter and undermine its desired functionality.
[0017] Simple and safe blood filtering and guidewire systems that
can be temporarily placed in the vasculature to prevent distal
embolization during endovascular procedures, and that can be used
to introduce and/or exchange various instruments to a region of
interest without compromising the position of the filter or
guidewire, are required. Existing guidewire-based embolic filtering
devices are inadequate for these and other purposes. The present
apparatus, in contrast, provides a novel means of providing these
and other functions, and has the further benefit of being easier to
manufacture than the devices of the prior art.
SUMMARY OF THE INVENTION
[0018] The present invention relates to seamless implantable
devices, filters, methods of manufacture, systems for deployment
and methods of use.
[0019] One aspect of the present invention is to provide a low
profile filter formed from a single piece of material.
[0020] Another aspect of the present invention is to provide a
self-expanding filter that is seamless.
[0021] A further aspect of the present invention is to provide an
integral self-expanding filter frame that is seamless.
[0022] A still further object of the present invention is to
provide a seamless, low-profile filter that minimally perturbs
flow.
[0023] A further aspect of the present invention to provide a low
profile, seamless filter that is readily connected to the guidewire
of a endoluminal deployment system.
[0024] A further aspect of the invention is to provide a filter
apparatus, which maintains vessel wall apposition and a maximally
open mouth when deployed in tortuous anatomy.
[0025] A further aspect of the invention is to provide a filter
frame, which can be rendered sufficiently radiopaque.
[0026] A further aspect of the present invention is to provide
filters which have increased capture efficiency and are capable of
providing drug delivery.
[0027] A further aspect according to the present invention includes
providing a seamless frame having a proximal end, a longitudinal
axis, a seamless support member circumscribing the axis and
distally spaced from the proximal end, and at least one attachment
strut, and optionally at least one filter strut seamlessly
extending from the support member.
[0028] Another aspect of the present invention is to provide a
seamless frame having a proximal end, a longitudinal axis, a
seamless support member circumscribing the axis and distally spaced
from the proximal end, and at least one attachment strut,
optionally at least one filter strut seamlessly extending from the
support member, and at least one or more filter media layers.
[0029] Another aspect of the present invention is to provide
implantable devices that may be configured as detachable devices
designed for permanent implantation and/or subsequent retrieval and
are used for: temporary vascular occluders; exclusion of bleeding
varices or aneurysmal vascular segments; a stent, or similar means
of providing structural support to an endoluminal cavity; a
thrombectomy/atherectomy instrument; an implantable prosthetic
vascular conduit wherein the proximal filter frame functions as an
anchoring stent, and the distal filter is configured into an
open-ended, tubular configuration (similar to a windsock) allowing
endoluminal lining of a vascular segment with a biocompatible
liner.
[0030] An aspect of the present invention is to provide seamless
implantable devices formed from a single piece of material.
[0031] Another aspect of the present invention is to provide
seamless implantable devices that have regions of articulation
and/or radiopaque markers.
[0032] A further aspect of the present invention to provide
seamless implantable devices that include radiopaque markers.
[0033] A still further aspect of the present invention is to
provide stents or similar means of providing structural support to
an endoluminal cavity, and which may include regions of
articulation and/or radiopaque markers.
[0034] A further aspect of the present invention to provide a
seamless stent, or similar means of providing structural support to
an endoluminal cavity.
[0035] A still further aspect of the present invention is to
provide a delivery system for the inventive seamless devices,
stents, occluders, filters and its use. These and other features
and aspects of the invention will become more apparent in view of
the following detailed description, non-limiting examples, appended
claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIGS. 1A, 1B and 1C illustrate the steps of constructing a
first two-dimensional frame, whereas FIGS. 1D and 1E illustrate a
resulting three-dimensional shape with a filter media attached
thereto.
[0037] FIGS. 2A, 2B and 2C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0038] FIGS. 3A, 3B and 3C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0039] FIGS. 4A, 4B and 4C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0040] FIGS. 5A, 5B and 5C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0041] FIGS. 6A, 6B and 6C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0042] FIGS. 7A, 7B and 7C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0043] FIG. 7D illustrates an annealed frame pattern having
articulation segments in the attachment struts and FIG. 7E
illustrates a frame pattern having longitudinally spaced support
members interconnected by articulation segments.
[0044] FIGS. 8A, 8B and 8C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0045] FIGS. 9A, 9B and 9C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0046] FIGS. 10A, 10B and 10C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with an integral filter media.
[0047] FIGS. 11A, 11B and 11C respectively illustrate an alternate
configuration of a two-dimensional frame, a resulting
three-dimensional shape after annealing and a depiction of the
frame with a filter media attached.
[0048] FIGS. 12A, 12B, 12C, 12D and 12E respectively illustrate
alternate apex and strut configurations adapted to accept and house
radio-opaque markers.
[0049] FIG. 13 illustrates a three-dimensional frame with an
attached filter media positioned between a guidewire and an
atraumatic tip.
[0050] FIGS. 14A and 14B depict the filtering apparatus as deployed
within a vessel having tortuous anatomy.
[0051] FIG. 15 illustrates an alternate system for assembling an
alternate embolic filter configuration.
[0052] FIG. 16 illustrates a system for assembling a
filter-in-filter device.
[0053] FIG. 17 illustrates the filter-in-filter assembled using the
system of FIG. 16.
[0054] FIGS. 18A, 18B and 18C respectively illustrate a tooling
device, a two-dimensional frame being formed into a
three-dimensional configuration, and the tooling device supporting
the three-dimensional frame for annealing.
[0055] FIGS. 19A, 19B and 19C respectively illustrate the steps for
converting a conical filter into "sombrero" shaped filter
configuration.
[0056] FIG. 19D illustrates a three-dimensional frame supporting a
"sombrero" shaped filter media.
[0057] FIGS. 19E and 19F depict an alternative filter sack
configuration in which the sack resembles an asymmetric cone.
[0058] FIGS. 20A, 20B and 20C respectively illustrate a
filter-in-filter configuration with a pharmacological agent loaded
in the space between the filter media, an alternate filter
configuration with the filter media pre-loaded with the
pharmacological agent, and the elution of the pharmacological agent
in a lumen/vessel of a host.
[0059] FIGS. 21A and 21B respectively illustrate deployment of an
occluder device in a lumen/vessel of a host and the detachment of
the occluder.
[0060] FIGS. 22A and 22B respectively illustrate the deployment of
an obstruction remover and collection of removed lesion debris in a
lumen/vessel of a host.
[0061] FIGS. 23A, 23B and 23C illustrate the use of an anchoring
device for treatment of a lesion in tortuous vessels associated
with renal anatomy.
[0062] FIGS. 24A, 24B, 24C, 24D and 24E respectively illustrate a
two dimensional frame, a three-dimensional resulting shape, an
endovascular device formed from the three-dimensional frame and an
open-ended windsock, the occlusion of a sacular aneurysm in a host
lumen/vessel with the endovascular device and optional use of a
stent lining the device.
[0063] FIG. 25A illustrates a delivery catheter having a guidewire
lumen and guidewire supported filter.
[0064] FIGS. 25B, 25C, 25D and 25E respectively illustrate views of
alternate distal catheter delivery tips.
[0065] FIGS. 25F, 25G and 25H respectively illustrate
three-dimensional top views of catheter tube having a channel
indented in its surface adjacent its distal end, a sleeve covering
the indented channel and a guidewire located in the sleeve
covered-indented channel.
[0066] FIGS. 26A, 26B, 26C 26D and 26E respectively illustrate
steps followed in treating a lesion in a host lumen/vessel.
[0067] FIGS. 27A, 27B and 27C respectively illustrate a view of the
distal tip a delivery catheter with an alternate auxiliary lumen
configuration, a three-dimensional top view of the auxiliary lumen
configuration and an auxiliary lumen mounted guidewire.
[0068] FIG. 28 illustrates a configuration of the present invention
deployed as an implantable vena cava filter.
[0069] FIGS. 29A and 29B respectively illustrate an alternate
two-dimensional planar configuration of the present invention, and
a three-quarter isometric view of this configuration formed into a
three-dimensional shape designed for use as an implantable
stent.
[0070] FIG. 30 is a flat pattern view of a filter frame and
integral tether elements as would be cut from a tube.
[0071] FIG. 31 is a flat pattern view of a filter frame and
integral tether elements after being formed and annealed at a
functional size.
[0072] FIGS. 32A, 32B, 32C, 32D and 32E respectively show
variations in the tether geometry, designed to allow the tethers to
articulate with respect to one another and to the filter frame
itself.
DETAILED DESCRIPTION OF THE INVENTION
[0073] As used herein the following terms are defined as
followed:
[0074] The term "proximal" is defined as the location closest to
the catheter hub and "distal" is the location most distant from the
catheter hub. With respect to the inventive three-dimensional
uni-body frame, the term "proximal" is the frame end attached to
the guidewire or the frame side through which debris enters to be
collected by an associated filter.
[0075] The term "uni-body" refers to a frame pattern formed from a
single piece of material and therefore considered "seamless."
[0076] Terms such as unitary, integral, one-piece are synonymous
with "uni-body" and also refer to a frame pattern that is formed
from a single or common piece of material.
[0077] Filament, wire or ribbon are alternate terms used to
describe the portions/sections of pattern material that remain
after etching a planar precursor frame material and form the
attachment struts, the support struts, the filter/filter support
struts that extend in the longitudinal, circumferential, or any
other direction necessary to define a frame pattern.
[0078] FIGS. 1A-1D schematically show the four method steps that
are followed to manufacture a uni-body, self-expanding filter
device in accordance with the present invention. FIG. 1A shows a
flat sheet material 110, preferably a shape memory alloy material,
e.g., a NiTi alloy, Nitinol, or any other suitable bioacceptable
material, such as a metal, e.g., stainless steel, or bioacceptable
polymer. The flat sheet material 110 is used to form the "uni-body"
frame pattern 115 of FIG. 1C, or other frame patterns described
hereinafter.
[0079] A desired pattern is formed on sheet material 110, as in the
case of FIG. 1B, which shows a radially symmetric filter frame
pattern having six "pie" shaped wedges 120. The wedges 120 are
removed by etching in a chemical photo-etching process, or any
other suitable technique, to form a frame defined by filament sized
material. The frame pattern can also be obtained by using a laser
or any other cutting procedure or process capable of precisely
etching, stamping, or otherwise cutting the flat sheet 110 into the
preferred shape.
[0080] Radial sides 125, 130 and arcuate side 135 circumscribe the
wedges 120. Slits 145 are formed and center section 150 is removed
by any suitable cutting technique. After the slits 145 are formed,
and wedges 120 and center section 150 removed, flashing 140 is
removed (such as by trimming with fine scissors or diagonal
cutters), leaving the desired skeletal two-dimensional filter
frame/pattern 115, shown in FIG. 1C.
[0081] Skeletal frame 115 includes attachment struts 155 with
proximal ends 165 that are to be fixed or attached to proximal
connecting member 170 of FIG. 1 D, adapted to cooperate with a
guidewire (not shown). Attachment struts 155 extend seamlessly from
support struts 156 because they are formed from the same precursor
material. Support struts 156 are seamlessly connected to or
seamlessly interconnected with one another.
[0082] Seamlessly interconnected support struts 156 define a
boundary, perimeter or cell having the configuration of a
six-pointed "star." When frame 115 is converted into a
three-dimensional configuration, the seamlessly
associated/interconnected struts 156 typically form a "closed"
support member 156A that circumscribes the longitudinal axis of the
three-dimensional frame, thereby providing a radial or transverse
dimension to the three-dimensional frame. The boundary, perimeter,
cell or support member 156A can be any geometric configuration so
long as it provides a radial dimension (transverse to the
longitudinal axis) for the frame. The support member circumscribes
the longitudinal axis of the frame and may also be described as
being ring-shaped. In addition to providing the frame with a radial
dimension, as shown in FIG. 1D, the support member 156A is
typically the location for attaching the proximal open end 161 of
the filter 160. Thus the support member also functions to maintain
the proximal end of filter media 160 in the open operative
configuration. Filter media 160 may be formed from any suitable
material, and also includes a closed distal end 162.
[0083] The planar, two-dimensional frame pattern of FIG. 1C is then
annealed, normally by thermal annealing, into a three-dimensional
configuration. The three-dimensional annealed frame configuration
175, may be further processed, as described hereinafter, to include
a filter media resulting in filter 100 which includes the frame 175
and filter media 160, as in FIGS. 1D and 1E. For ease of
consistency and brevity throughout the remainder of the application
and without relinquishing equivalents thereof, Nitinol is used as
the filter frame material in each and every embodiment shown and
described hereinafter. However, as discussed above, other suitable
materials, such as, titanium nickel alloys, shape memory materials,
biocompatible metals, e.g., stainless steel, or plastic may be used
for the uni-body filter frame.
[0084] FIGS. 2A-2C through 11A-11C depict alternate filter frame
patterns that can be formed following the procedures described with
reference to FIGS. 1A-1E. As a result, the various struts are
seamlessly interconnected since they are formed from the same
precursor material.
[0085] FIG. 2A illustrates a plan view of an alternate frame
pattern 215 having hoop shaped struts 256 connected to attachment
struts 255. FIG. 2B illustrates the three dimensional filter frame
275 after annealing with proximal ends of the attachment struts 255
fixed to the proximal connecting member 270 and struts 256
seamlessly connected to one another and forming a closed support
member 256A. As with FIG. 1C, struts 255 seamlessly extend from
support member 256A. FIG. 2C illustrates a filter 200 attached to a
guidewire 280. The filter 200 includes the three-dimensional frame
275 with a filter media 260 having a "butterfly" configuration. The
configuration of filter media 260 can also be described as
substantially parabolic.
[0086] FIG. 3A illustrates an alternate two-dimensional (plan view)
frame pattern 315 having attachment struts 355, attachment strut
proximal ends 365, filter struts 385 which may also support
optional filter media 360 of FIG. 3D. Filter pattern 315 also
includes support struts 356. Support struts 356 and filter struts
385, which are seamlessly associated with one another, cooperate to
define cell 357, which is configured in the shape of a diamond.
Struts 355, 356 and 385 are seamlessly associated with one another
since they are formed from the same precursor material. Struts 356
define a boundary around six cells 357 and form a closed support
member 356A for maintaining the three-dimensional filter of FIG. 3C
in an open, operative configuration. FIG. 3B illustrates
three-dimensional frame 375 that is obtained after the two
dimensional filter frame pattern is annealed, with the proximal
ends 365 of the attachment struts 355 fixed to proximal connecting
member 370. In the embodiment of FIG. 3B, the filter struts 385
allow the device to be used as a filter, without the filter media
shown in FIG. 3C. While the filter pattern of FIG. 3B shows six
filter struts 385, any number of filter struts or support struts
can be used, including, but not limited to 4, 5, 7, 8, 9, 10, 11,
12, etc. In addition, although FIG. 3A depicts the filter frame 315
with diamond shaped cells/openings 357, cells 357 can be of any
geometrical shape or size, so long as the openings are of
sufficient size to permit blood flow and/or filtering. FIG. 3C
illustrates the annealed filter frame pattern of FIG. 3B with
filter media 360 attached to a guidewire 380.
[0087] FIG. 4A illustrates a two-dimensional alternate seamless
frame pattern 415 having attachment struts 455, support struts 456,
and filter/filter media support struts 485. The pattern is seamless
because it is formed from the same precursor material. FIGS. 4B and
4C illustrate three-dimensional views of filter frame pattern 475
after annealing, with the proximal ends of the attachment struts
455 fixed to the proximal connecting member 470, support struts 456
forming support member 456A, and filter media support struts 485
extending in a distal direction. FIG. 4C illustrates the annealed
filter frame pattern 475 of FIG. 4B with filter media 460 attached
to a guidewire 480.
[0088] FIG. 5A illustrates the two-dimensional alternate seamless
filter pattern 515 having attachment struts 555, support struts
556, filter media support members 590, and filter support struts
585. The pattern is seamless because it is formed from the same
precursor material. FIGS. 5B and 5C illustrate three-dimensional
views of the filter frame pattern 515 of FIG. 5A after annealing,
frame 575, with proximal ends of the attachment struts 555 fixed to
the connecting member 570, support struts 556 of FIG. 5A form
closed support member 556A, and filter media support struts 585
extend distally away from the proximal connector 570. FIG. 5C
illustrates the annealed filter frame pattern 575 of FIG. 5B with
filter media 560 attached to a guidewire 580.
[0089] FIG. 6A illustrates the two-dimensional alternate seamless
filter pattern 615 having attachment struts 655, support struts 656
and filter support struts 685. The pattern is seamless because it
is formed from the same precursor material. FIGS. 6B and 6C
illustrate three-dimensional views of filter frame pattern 615 of
FIG. 6A after annealing, with the proximal ends of the attachment
struts 655 fixed to the connecting member 670, support struts 656
of FIG. 6A forming support member 656A and filter media support
struts 685. FIG. 6C illustrates the annealed filter frame pattern
675 of FIG. 6B with filter media 660 attached to a guidewire
680.
[0090] FIG. 7A illustrates a two-dimensional view of a seamless
alternate filter pattern 715 having attachment struts 755 and
support member struts 756. The pattern is seamless because it is
formed from the same precursor material, for supporting the open
end of filter media 760 of FIG. 7C. FIGS. 7B and 7C illustrate side
views of the three-dimensional filter frame 775, after annealing,
with the proximal ends of the attachment struts 755 fixed to the
connecting member 770 and support struts 756 of FIG. 7A forming
support member 756A. FIG. 7C illustrates the annealed filter frame
pattern of FIG. 7B with filter media 760 attached to a guidewire
780. FIG. 7D illustrates the annealed frame pattern having
articulation segments 790 in the attachment struts 755. FIG. 7E
illustrates an alternate design, wherein there are two
longitudinally spaced support members 756A seamlessly
interconnected to one another by articulation segments 790,
described in greater detail hereinafter.
[0091] FIG. 8A illustrates a two-dimensional view of an alternate
spirally configured filter pattern 815. FIGS. 8B and 8C illustrate
three-dimensional views of the filter frame pattern 815 of FIG. 8A
after annealing, frame 875, with a proximal end of the frame 875
fixed to the connecting member 870. FIG. 8C illustrates the
annealed filter frame pattern of FIG. 8B with filter media 860
attached to a guidewire 880. In the filter frame illustrated in
FIG. 8B, one of the turns of the spirally shaped frame, which is
not "closed," forms the support member that provides radial
dimension to the frame.
[0092] FIG. 9A illustrates a two-dimensional view of an alternate
seamless filter pattern 915 having attachment struts 955 and filter
media support struts 985. The pattern is seamless because it is
formed from the same precursor material. FIGS. 9B and 9C illustrate
three-dimensional views of the filter frame pattern after
annealing, frame 975, with the proximal ends of the attachment
struts 955 fixed to the proximal connecting member 970. In this
embodiment the filter media support struts 985 closest to the
proximal connector also function as the closed support member
described herein to provide the transverse dimension of the frame
and support the proximal end of the filter 960. FIG. 9C illustrates
the annealed filter frame pattern 975 of FIG. 9B and filter media
960 attached to a guidewire 980.
[0093] FIG. 10A illustrates a two-dimensional view of an alternate
seamless filter pattern 1015 having attachment struts 1055 and a
central portion of the planar Nitinol precursor material 1010
rendered porous 1090. FIGS. 10B and 10C illustrate
three-dimensional views of the filter frame pattern 1015 of FIG.
10A after annealing, frame 1075, with the proximal ends of the
attachment struts 1055 fixed to the connecting member 1070, and the
porous precursor material 1090 having pleats 1095. FIG. 10C
illustrates the annealed filter frame pattern 1075 of FIG. 10B
attached to a guidewire 1080. A separate filter media is not
necessary in the embodiment illustrated in FIGS. 10A-11C because
the porous precursor portion 1090 serves as the filter media.
[0094] FIG. 11A illustrates a two-dimensional view of an alternate
seamless filter pattern 1115 having attachment and filter strut
1156 which will also function as the closed support member 1156A
shown in FIG. 11B. FIGS. 11B and 11C illustrate three-dimensional
views of the filter frame pattern 1115 of FIG. 11A after annealing,
frame 1175, with the proximal end of the closed support member
1156A fixed to the connecting member 1170. FIG. 11C illustrates the
annealed filter frame pattern 1175 of FIG. 11B with filter media
1160 attached to a guidewire 1180.
[0095] Although the above embodiments show a single support member
156A, 256A, 356A, 456A, 556A, 656A, 756A, 956A, etc., it is clearly
within the scope of the invention to have a plurality of
longitudinally spaced support members, i.e., members that
circumscribe the longitudinal axis of the frame, that are
seamlessly interconnected with one another via struts or
articulation segments, as in FIG. 7E. Similarly other embodiments
described hereinafter may also include a plurality of seamlessly
interconnected support members where the mechanism for
interconnection includes struts, and/or the articulation segments
which are defined hereinafter. In addition, when there are more
than two support members connected to one another, some or all may
be interconnected with struts and some or all may be interconnected
via articulation segments. Thus, there could be a series of two,
three, four or more members, and in the case with at least three
support members that circumscribe the pattern's longitudinal axis,
both struts and articulation segments can be used in an alternating
pattern.
[0096] FIGS. 12A, 12B, 12C, 12D and 12E illustrate alternate
configurations of stent strut, and apex designs which allow for,
accept and house ancillary components. FIG. 12A depicts a housing
1210, which could be machined, stamped, lasered or etched into the
stent frame. Housing 1210 is then filled with a material 1250 such
as gold or platinum-iridium (to provide enhanced radio-opacity) or
with a therapeutic agent such as a drug (to provide a prescribed
biological response). FIG. 12B depicts housing 1210 located along
the side of a strut. FIG. 12C depicts multiple housings 1210 along
a strut. FIG. 12D depicts multiple housings 1210 located within the
strut periphery. FIG. 12E depicts an alternate shape (arrowhead)
housing 1210 (to be used as a radiopaque marker housing) located
within the strut periphery. It should be noted that multiple shapes
and sizes of housings could be configured. The radiopaque markers
could be located in any strut or support member of the frame of the
filter or the stent. Advantages of the application of radio-opaque
markers in the fashions shown are: 1) stent cross section thickness
is not increased (lending to reduction in introductory device
profiles), 2) allows for precise and uniform spacing of markers,
and 3) allows for a multitude of shapes (dots, arrows and other
characters such as letters or words) to be easily incorporated into
the frame. The housings may also provide a cavity in which to
insert and/or attach onboard electronics or sensors.
[0097] FIG. 13 illustrates an embolic filter assembly system 1300
that includes three functionally distinct regions. Section 1300A
includes a support wire that terminates at its distal end in
connecting member 1370. The support wire may be the guidewire 1380
used to deliver a therapeutic device, e.g., a deployment catheter
or angioplasty balloon. Section 1300B is any one of the embolic
filter devices described in FIGS. 1A-1E through 11A-11C described
herein, or another other device described hereinafter. Section
1300C may include an atraumatic tip 1396 or other suitable tip
known to those skilled in the art having a proximal end
fixed/attached/cooperating with distal connecting member.
[0098] FIG. 14A depicts the filter apparatus 1400 as deployed in a
vessel 1420 with tortuous anatomy. As shown, such a condition
results in a non-linear apparatus deployment configuration. In
order for filter frame 1410 to maintain sufficient vessel wall
apposition (which eliminates peri-device channel formations), the
tether elements 1430 must be capable of deforming and/or
articulating.
[0099] FIG. 14B depicts the filter apparatus 1400 as deployed at a
different site within the same vessel 1420 anatomy of FIG. 14A,
once again demonstrating the flexibility required of the deflecting
and articulating tether elements 1430. It is clear in this
depiction that the guidewire 1440 does not necessarily follow the
host vessel centerline. This phenomenon, coupled with anatomical
variances and the requirement of complete vessel wall apposition of
the filter frame 1410 makes the inclusion of articulating tether
elements 1430 a benefit and necessity for safe and confident
embolic protection of downstream vasculature.
[0100] FIG. 15 illustrates an arrangement to attach a filter media
to any of the annealed filter frames described herein. The frame
1515, is sandwiched between filter media portions 1560A and 1560B,
which are respectively sandwiched between cushion elements 1500C
and 1500D, which layered assembly is located between heated top
plate 1500A and heated base plate 1500B. Thus, resulting
three-dimensional lamination of FIG. 15 has a cross-sectional view
that is substantially conical. Application of heat and pressure,
via heated platens 1500A and 1500B, result in the integral bonding
of the filter media 1560A and 1560B, and the interposed frame 1515.
The filter frame configuration via the lamination procedure
depicted in FIG. 15 results in a filter assembly configuration
resembling a "butterfly net."
[0101] FIG. 16 schematically shows an alternate procedure for
attaching filter media to an annealed filter frame. In FIG. 16, an
annealed filter frame 1615 is sandwiched between adjacent laminae
of inner filter media 1 660A and outer filter media 1660B. Heat and
pressure are applied via upper and lower punch and die platens
1600A and 1600B. The application of heat and pressure results in an
integral bonding of the filter media 1660A and 1660B and interposed
frame 1615. During the heating and pressure lamination process, a
vacuum may be applied in the lower platen 1600B thereby bonding the
filter media and skeletal filter frame together. The filter media
shown in FIG. 16 is normally interposed only within the immediate
vicinity of the filter frame 1615. Additionally, the application of
the vacuum can be used to optimize the filter frame geometry. The
method shown in FIG. 16 can produce a filter frame configuration
that resembles a butterfly net, such as the one shown in the device
of FIGS. 7A-7C. This method can also be used to produce a
frame-supported "filter-in-filter," which is shown in further
detail in FIG. 17, described below.
[0102] FIG. 17 shows an alternate embodiment of the present
invention incorporating a two stage "filter-in-filter" design. The
filter-in-filter design will provide improved filtration
efficiencies, such as allowing each filter lamina to have a
different porosity by using an inner filter media 1760A and an
outer filter media 1760B. Alternatively, either filter media 1760A
or 1760B can incorporate an integral Nitinol frame as one of the
filter members. Alternatively still, both the inner and outer
filter media 1760A and 1760B could be an integral Nitinol filter
frame. Use of an uni-body Nitinol frame, such as those described
herein, would provide additional structural benefits in the
completed filter frame apparatus.
[0103] FIGS. 18A, 18B, and 18C schematically illustrate an
annealing method in which a planar, two-dimensional filter frame is
converted into a three-dimensional configuration with the use of an
appropriate fixturing/tooling device, e.g., a mandrel. Mandrel
1800A, shown in FIG. 18A, is used to form the filter frame 1815 of
FIG. 18B into the desired shape. After cutting a flat metal sheet
into the desired two dimensional configuration, such as that
described above, the proximal ends 1865 of attachments struts 1855,
i.e., the endpoints of the two-dimensional filter frame 1815, are
collected at a point along the axis of radial symmetry as shown in
FIG. 18B. As depicted in FIG. 18C, the filter frame 1815 is placed
onto the fixturing device, which, in this case, is the mandrel
1800A of FIG. 18A to impart a defined, three-dimensional
configuration, and the frame 1815 of FIG. 18B is annealed to
preserve the desired configuration. After annealing, the
three-dimensional filter frame 1875 can be elastically deformed
into its original two-dimensional shape where a filter media can be
applied according to any of the methods described and illustrated
herein.
[0104] Following the attachment of the filter media, the
three-dimensional filter configuration is readily obtained.
[0105] FIGS. 19A, 19B, 19C and 19D illustrate an alternate filter
configuration using a "sombrero" shaped filter media 1960B with a
supporting frame. To form the sombrero frame and filter shown in
FIG. 19D, a conical filter 1960, as shown in FIG. 19A, has its
closed distal end 1962 inverted toward the open proximal end 1961
of the conical filter 1960, to form a convex, hat-like base as
shown in FIG. 19B. This inversion shortens the filter length, but
retains the original area of the filter element 1960. Next, the
convexity is increased until the apex 1963 extends beyond the open
end 1961, as shown in FIG. 19C. The filter 1960 thus has been
shortened further, but the effective filter area still remains
identical to the original conical filter area. The sombrero filter
1960B is attached to frame 1975, FIG. 19D. The frame includes
attachment struts that are fixed to a connecting member 1970, which
in turn is cooperatively associated with a guidewire 1955. Compared
to conventional conical filter frame designs, the sombrero filter
frame allows more surface area per unit length, or, alternatively,
reduces filter length without compromising filter surface area and
deflection of the trapped debris away from the vessel centerline.
The desired sombrero filter frame configuration will also increase
the reliable removal of entrapped debris.
[0106] FIGS. 19E and 19F depict an alternate filter sack
configuration, also designed to collect and hold embolic debris
away from the vessel centerline. In this case, an asymmetric cone
shaped filter media sack 1990 is produced and attached to the
filter frame 1960. Collected emboli will tend to collect at the tip
of the sack 1990 and are t held offset in the vessel, thus allowing
relatively unperturbed flow at the vessel centerline.
[0107] As shown in FIGS. 20A, 20B and 20C, a filter in accordance
with the present invention can be used to deliver a pharmaceutical
substance, anti-thrombotic agent, drug, etc., into the blood flow
in a host lumen/vessel by deploying the filter in a lumen/vessel of
interest. In FIG. 20A, a filter device such as that described in
FIG. 17 above, can be loaded with a pharmacological agent in one or
more different areas before delivery into the host. Thus, the drug
can be loaded between layers of the filter media. The drug 2098 may
be retained within the zone/space/area between the inner filter
media 2060A and outer filter media 2060B ready to be delivered to
the host.
[0108] Instead of using the filter-in-filter design of FIG. 17, any
of the other filter configurations described herein can be used by
imbibing the drug into the filter media itself. As shown in FIG.
20B, the drug 2098 can be imbibed into the media 2060 itself.
[0109] FIG. 20C illustrates drug administration in the host by
deploying the drug delivering system of FIGS. 20A or 20B in a host
lumen/vessel so that the blood flows through the filter media to
elute the pharmacological agent, e.g., drugs. This method of
localized drug delivery is effective for eluting a pharmacological
agent contained either between adjacent layers of filter media or
imbibed directly into the filter media. Fluid flow through the
filter device of FIGS. 20A or 20B, or any other filter
configuration described herein containing pharmacological agents
provides a mechanism of mass transfer to downstream perfusion beds.
The pharmacological agent could be pre-loaded into the filter or
injected post deployment perhaps through an extension of the
support/guidewire.
[0110] As shown in FIGS. 21A and 21B, occluding device 2175 can be
formed as a detachable endoluminal filter frame that can be
implanted in the host. The occluding device 2175 thus implanted can
either be permanently implanted or retrieved at a later point in
time, such as is required in vena cava filtering applications. As
shown in FIG. 21A, blood flow through the host can be obstructed by
the implantation of the filter frame apparatus 2100. The filter
frame apparatus 2100, used as an indwelling or implantable
occlusion device is shown in FIG. 21A. As shown in FIG. 21B, a
guidewire or support wire 2180 includes a distal end 2181 that may
be detached from proximal connector 2170 that is connected to the
occluding device 2175 or filter frame apparatus 2100. The support
wire 2180 is used to position or remove occluding device 2175 or
filter frame apparatus 2100 from a lumen in a host. The guidewire
tip 2181 may be of any design for detachment from or reattachment
to proximal connector 2170. Thus, the guidewire 2180 can have any
capture capability, including screw threads, magnetic,
ball-and-socket, male-female attachment, bayonet, or any type of
coupling that will allow the guidewire 2180 to detach or reattach
to the proximal connector 2170 for placement or movement
therein.
[0111] FIGS. 22A and 22B illustrate the use of a filter (similar to
the filters 100 or 700, respectively shown in FIGS. 1D or 7C) to
remove flow obstructions or to function as a thrombectomy device to
remove intraluminal thrombus, for example. FIG. 22A shows an
obstruction at the lumen wall in a blood vessel of the host. Though
commonly the lesion will have formed in a restrictive manner, the
lesion is shown in a cross-sectional area with an upper and a lower
component, that has narrowed the effective diameter of the lumen.
Filter 2200 includes sharpened support members 2285 to enable the
filter to be used as a type of scraper. The frame 2275 shown herein
includes a filter media 2260 as a "catch bag." In FIG. 22B, the
filter 2200 is pulled with sharpened members 2285, effectively
shearing the obstruction/lesion from the vessel wall of the host.
As the lesion is sheared from the wall, sheared lesion parts are
collected in the catch bag or filter media 2260. In this manner,
the present filter frame can be used to remove lesions and collect
the debris dislodged into the blood stream, to lessen the
possibility of clotting downstream of the host vessel. This
approach can likewise be used to capture and remove foreign objects
from bodily passageways.
[0112] FIGS. 23A, 23B and 23C respectively illustrate the use of
the inventive filter as an anchoring guidewire to facilitate the
retention of a guidewire position in tortuous vessels of the renal
circulatory system, and in particular for branch lumens offset at
angles of approximately 90.degree.. Using the inventive filter
frame as an anchor avoids or minimizes damage to the host vessel,
and specifically avoids or minimizes damage to the endothelium of
the host lumen/vessel. FIG. 23A shows a lesion 2300A in a branch
lumen/vessel 2300B associated with the renal anatomy of a host. In
the non-limiting embodiment of FIGS. 23A-23C, the branch lumen
2300B includes an approximate 90.degree. turn toward the existing
anatomy shown. As illustrated in FIG. 23B a filter frame 2375 is
positioned and anchored in a renal circulatory vessel 2300B to fix
the position of the support wire 2380. A slight pressure is imposed
on the support wire 2380 and the approximate 90.degree. turn is
extended to more than 90.degree. without dislodging or altering the
position of the guidewire in relation to the host anatomy as shown
in FIG. 23B.
[0113] As shown in FIG. 23C, a therapeutic catheter 2300C can be
inserted over the support wire 2380 of the filter frame to perform
the intervention. As a result, therapy devices can more easily
negotiate a greater than 900 bend as shown in FIGS. 23B and 23C.
Such therapy devices include, but are not limited to balloons,
stents, etc. A further useful aspect of this embodiment is that,
during its use, a long "exchange length" guidewire is unnecessary.
Since this device is capable of maintaining it's positioning after
deployment, the necessity of "rapid exchange" or "monorail"
catheters are obviated.
[0114] FIGS. 24A, 24B, 24C, 24D and 24E show a further embodiment
of the present filter frame assembly, which is intended to function
as an implantable endoprosthesis 2476. As shown in FIGS. 24A and
24B, the initial seamless filter frame 2475 is formed from a
loop-type frame 2415 from the same precursor material. In FIG. 24C,
the proximal end of an open-ended "windsock" shaped graft component
2477 is attached to the loop of the filter frame 2475 to form an
endoprosthesis 2476. In FIG. 24D, the loop-type frame 2475 with the
attached open-ended windsock is deployed proximal to an aneurysmal
defect, and the windsock shaped graft component 2477 extends
downstream of the frame, effectively excluding the aneurysm 2400A.
Thus, frame and the opened ended sock function as an implantable
prosthetic vascular conduit where the filter frame 2475 functions
as an anchoring stent, and the open-ended sock functions as a
biocompatible liner. This device, shown in FIG. 24E, may then be
optionally lined with a stent 2480. This embodiment finds use as a
stent and graft combination where the stent element would be
deployed proximal to the intended therapy site and the graft
element would be configured to be deployed by blood pressure.
[0115] FIGS. 25A-25H illustrate an exemplary delivery system for
deploying the present filter frame 2575 or filter 2500 of the
present invention. FIG. 25A illustrates a frame 2575 or
frame-filter 2500, such as frame 175 or frame-filter 100 of FIGS.
1D or 1E, frame 375 or frame-filter 300 of FIGS. 3B and 3C, or any
of the other frame or frame--filter assembly herein described,
attached to a support or guidewire 2580 and positioned within a
tubular delivery sheath 2500A of a delivery catheter. FIGS. 25B-25D
illustrates front views taken from sectional plane A-A of FIG. 25A,
but without the frame 2575 or frame-filter 2500. The section A-A1
(FIG. 25B) illustrates a dual lumen extrusion catheter sheath.
Section A-A2 (FIG. 25C) illustrates a single lumen extrusion having
an additional covering formed from a shrink tube. Section A-A3
(FIG. 25D) illustrates a second lumen adhered to the inner diameter
of the tubular delivery sheath 2500A of FIG. 25A.
[0116] FIG. 25E-25H illustrate the perspective detail of external
guidewire 2580 loading of a catheter lumen. FIG. 25E is a front
view of the FIG. 25G. FIG. 25F illustrates the catheter having a
longitudinally extending indented channel, which, as seen in FIG.
25G is circumscribed by a tubular section 2500C. The guidewire 2580
is inserted into the longitudinally extending channel 2500B between
the external wall of the catheter and the tubular section 2500C. In
use, a filter frame or filter-frame construct is pre-loaded into
the distal end of the sheath adjacent to an exterior wire guide
channel. The exterior wire guide is adapted to receive a guidewire
in a rapid exchange configuration, however, unlike the prior art,
the filter frame and guidewire 2580 are completely segregated and
no aperture exists.
[0117] FIGS. 26A, 26B, 26C, 26D and 26E illustrate a method of
using a filter frame assembly 2600 in accordance with the present
invention. In FIG. 26A, a lumen/vessel 2600A of the host has a
lesion 2600B. A guidewire 2680 is deployed into the lumen/vessel
2600A past the target lesion 2600B. Thereafter, guidewire 2680 is
back-loaded into the delivery system 2600C, such as the one
described in FIGS. 25B-25D, 25F-25G, or FIG. 27B. Then the delivery
sheath 2600C is advanced across the target lesion 2600B. The
delivery sheath 2600C is withdrawn, thereby allowing a
self-expanding filter 2600 to deploy. The self-expanding filter
2600 is normally designed to deploy spontaneously after the
delivery sheath 2600C has been withdrawn in this manner. Thus, as
shown in FIG. 26C, the filter 2600 is deployed downstream of the
lesion 2600B. A therapeutic catheter 2600D, such as an angioplasty
balloon, is routed over the support wire 2680 in FIG. 26D to treat
target lesion 2600B. As also shown in FIG. 26D, when the therapy is
performed, the filter 2600 functions to capture any emboli
dislodged or removed by the therapeutic catheter 2600D. Thereafter,
as illustrated in FIG. 26E, the filter 2600 is removed via
insertion of a tubular capturing catheter 2600E over the support
wire and retraction of the filter 2600 into the capture catheter
2600E is performed. This retraction can be performed by pulling the
filter 2600 partially back into the capture catheter lumen 2600E,
effectively trapping the emboli 2600F. In this manner, the lesion
is dissipated through a therapeutic catheter without the result of
any of the dislodged emboli or debris dislodging into the host.
[0118] FIGS. 27A, 27B and 27C illustrate a lumen 2710 having an
auxiliary, internally positioned channel 2720 for receiving a
guidewire 2730. FIG. 27A illustrates the tip of the sheath having
an internally located, peripherally positioned auxiliary channel
2720 formed by "pinching" the end of the tube wall as shown in FIG.
27B. FIG. 27C shows the guidewire 2730 inserted through into the
slit opening in the side of the catheter and exiting the tip.
[0119] FIG. 28 illustrates the use of the inventive filter 2800, as
a vena cava filter. Since the inventive filters described herein
may be readily detachable, the filter 2800 can be readily detached
from a deployment guidewire.
[0120] FIG. 29A illustrates a planar two-dimensional seamless
pattern, formed from metallic material, or any other suitable
biocompatible material. FIG. 29B illustrates a three-dimensional
stent member formed from the planar two-dimensional pattern of FIG.
29A, for use as an intraluminal stent. When extremely thin wall
sections are required, such as in coronary stents, it is
appropriate to fabricate the device from a planar sheet of
material.
[0121] Planar material can be manufactured thinner than tubing due
to the extra requirements of concentricity placed upon tubing
stock. It should be noted that although only one design has been
depicted, a wide variety of patterns and cell geometries may be
produced from planar material. The various cell geometries are
defined by the interconnected struts of the stent. In FIGS. 29A and
29B four interconnected struts 2910 define the four sided cell
2920. This planar material may be metallic or polymeric or a
combination thereof, and in any case, may also be porous. Once the
flat pattern is fabricated, it is formed into a 3-D shape (in the
depicted instance, an open mesh tube). The formed stent may be
either plastically deformable (and thus made from a malleable
starting material) or may be self-expanding, in which case a
super-elastic, pseudo-elastic or shape memory material may be used.
Subsequent processing such as thermal treatment, diametric
reduction, de-burring and polishing may be incurred, depending upon
the specific stent design. It should be understood that multiple
3-D stent "units" could be manufactured in such a way and attached
together to form a much longer device.
[0122] FIG. 30 depicts a view of a flat pattern of filter frame
3010A and integral tether element 3010B geometry as it would be cut
from a tube. This tube may be made of a shape memory alloy such as
Nitinol. Cutting could be accomplished by a variety of methods
including machining, laser cutting, stamping or etching.
[0123] FIG. 31 depicts the flat pattern geometry of FIG. 30
subsequent to forming and annealing at a larger, functional size.
Upon annealing, the filter frame 3010A resiliently maintains this
larger diametrical profile and the at least one tether element
3010B extends seamlessly from it.
[0124] FIGS. 32A-32E depict alternate articulation segments formed
as an integral part of the tether element thereby forming different
tether element geometries, which allow articulation of the tether
elements 3010B in relation to the filter frame 3010A. FIG. 32A
depicts the tether element 3010B with an area of reduced strut
width e.g. reduced cross-sectional area, to allow increased
flexibility. FIG. 32B depicts tether element 3010B with several
individual areas of reduced strut width to allow increased
flexibility. FIG. 32C depicts tether element 3010B with a reduced
width and formed "hinging" area to increase flexibility. FIG. 32D
depicts tether element 3010B with a reduced width and several
formed "hinging" areas to increase flexibility. FIG. 32E depicts
tether element 3010B divided in two for a portion of its length.
This division effectively increases the tether element flexibility
so as to allow articulation. The articulation segment of the tether
element, therefore, is configured to enhance the flexibility of the
filter apparatus (and thus, conformance to the host vessel wall) as
well as to minimize inadvertent trauma translated to the host
vessel wall by movement or manipulation of the guidewire.
[0125] An articulation segment of the tether elements or struts is
a desirable feature in that it allows adequate vessel wall
apposition of the filter frame when the filter device is deployed
in a curved segment of anatomy. In a curved segment, the tether
element articulates and deflects to adjust for a non-linear
deployment situation (See FIG. 14). Thus, the filter frame itself
can maintain an uncompromised and fully deployed condition.
Likewise, because of its ability to attenuate longitudinal
translation, the articulation segment provides a means of
mitigating trauma of the host vessel wall due to guidewire
manipulation. It should also be noted that the required deflection
and articulation of the tether elements could be bought about by
metallurgical means rather than, or in combination with,
geometrical means. For instance, the tether 3010B and frame 3010A
elements of FIGS. 32A-E, although seamless and integral, may be
exposed to different thermal processing parameters (for example:
through the use of fixturing to provide differential heat sink
qualities), thus rendering the tether 3010B ductile and pliable
while the frame 3010A maintains the stiffness required for adequate
vessel wall apposition.
[0126] The articulation segments, though described with respect to
the various frame patterns can be incorporated into any of the
endovascular devices described herein. An articulation segment is a
localized region that provides enhanced longitudinal flexibility. A
localized region may have a cross-sectional area that is the same
as the remaining part a strut, but differs in geometry.
Alternatively, the localized region could have the same geometry
but a different cross-sectional area, or both the cross-sectional
area and geometry of the localized region differ from the remaining
part of the strut. An endovascular stent can have articulation
segments in any of the interconnected struts of FIGS. 29A and
29B.
EXAMPLES OF THE PRESENT INVENTION
Example 1
Nitinol Sheet Filter Frame and integral Tethers
[0127] A radially-symmetric geometrical pattern comprising
interconnected struts forming closed polygonal shaped cells was
chemically etched from a sheet of Nitinol (NiTi) to produce a
skeletal filter frame. The etching, preferably photoetching of
Nitinol (Kemac Technologies, Irwindale, Calif.) is continued to
achieve a desirable material thickness, to optimize the moment of
inertia of the struts and to polish the surface finish.
[0128] This filter frame is then subjected to a thermal treatment
to set the phase transition temperature of the NiTi to
approximately 37.degree. C. by heating the filter frame to a
temperature of about 450.degree. C. for about 10 minutes in an air
convection oven (Carbolite Corporation, Sheffield, England)
followed by a rapid quench in ambient temperature water.
[0129] The NiTi filter frame was then laminated between two (2)
layers of an adhesive-coated porous polymer. The layers were
positioned with the adhesive sides facing toward each other, and
facing toward the NiTi. The adhesive was used to adhere the layers
of film together as well as to the NiTi wire framework. A
sacrificial porous polymer cushion material was used on each side
of the device during this lamination procedure to provide
compliance of the surface during compression. This compliance
allows the earlier mentioned porous polymer membrane to conform to
the wire shape. The composite sub-assembly which included cushion,
porous polymer/adhesive laminate, NiTi, adhesive/porous polymer
laminate, and cushion layers was then compressed in a SST fixture
and heat treated at 320.degree. C. for 45 minutes in an air
convection oven (Grieve Oven, The Grieve Corporation, Round Lake,
Ill.).
[0130] Once the `sandwiched` device was removed from the heat
source and allowed to cool, the sacrificial cushion material was
peeled away from each side of the device and the NiTi wires were
disengaged from the fixture. A circular shape of approximately
0.625" in diameter was trimmed into the porous polymer using a
20-watt carbon dioxide laser. The remainder of porous polymer was
trimmed from the wire frame by hand and discarded-.
[0131] Following the laser trimming operation (which can also be
used to create the necessary pores in the filter media), the
radially-oriented arms (struts) of the device were folded up and
back on themselves to achieve a hollow, three dimensional,
semi-conical shape. To maintain the device in this configuration,
the NiTi struts were inserted into a SST tube. This tube measured
approximately 0.05" in length.times.0.035" outer
diameter.times.0.025" inner diameter. This tube and indwelling NiTi
wires were then crimped to a 0.014" diameter guidewire to provide a
guidewire based endoluminal embolic protection device. The device
resembled a three dimensional "whisk" shape with a pleated porous
polymer filter element attached to it.
[0132] The resulting pleats are designed to increase filter media
surface area over the generally conical shapes found in the prior
art. This increase in surface area also allows for a shorter filter
length which enhances deliverability of the device by a) decreasing
friction in the delivery catheter and b) improving device overall
flexibility.
Example 2
Nitinol Tube Filter Frame and Integral Tethers
[0133] A 1.3 mm Nitinol tube with a wall thickness of approx 0.1 mm
(obtained from Nitinol Devices and Components, Fremenot, Calif.)
was laser cut (Laserage Technologies Inc, Waukegan, Ill.) to a
single, undulating 6 apex ring geometry with integral tethers. This
frame was then lightly grit blasted at 40 psi with 20 micron
silicon carbide media in a grit blasting machine made by Comco Inc,
Burbank, Calif. The ring with integral tethers was then gently
pushed up a tapered mandrel until it achieved a functional size of
approx. 6 mm. The ring, tethers and mandrel were then subjected to
a thermal treatment to set the phase transition temperature of the
NiTi to approximately 37.degree. C. in an air convection oven
(Carbolite Corporation, Sheffield, England) One skilled in the art
will realize that variances in the geometry, metallurgy, thickness
and heat treating of the filter frame can all be varied to create
alternate embodiments with varying desirable properties. The ring
and tethers (now at functional size) were then lightly coated with
an fluorinated ethylene propylene (FEP) powder (FEP 5101 ,
available from Dupont Corp, Wilmington, Del.) by first stirring the
powder in a kitchen blender (Hamilton Beach Blendmaster, Wal-Mart)
after the power was mixed into a "cloud", the frame was hung into
the blender for enough time for FEP to build up onto the surface of
the ring. The frame, now coated with FEP powder was hung in an air
convection oven (Grieve Oven, The Grieve Corporation, Round Lake,
Ill.) set at 320.degree. C. for approx. one minute followed by air
cooling to room temp.
[0134] The NiTi frame was then set atop a filter sack and attached
though the application of localized heat (the heat causing the FEP
coating on the ring to re-melt and flow onto the surface of the
filter sack, thus providing a biocompatible thermoplastic
adhesive). The tether lines were then routed through a gold tube
(Johnson Matthey, San Diego, Calif.) radiopaque marker. The tethers
were pulled until they began to apply tension to the frame. A
guidewire was then inserted into the gold band (from the opposite
direction of the tether lines). The marker band was then crimped to
secure the tethers and guidewire together. A small amount of
instant adhesive (Loctite 401, Loctite Corp, Rocky Hill, Conn.) was
applied to create a smooth transition from the guidewire to the OD
of the gold band. One skilled in the art will realize that
attachment of the filter to the guidewire could be accomplished by
adhesion, welding, soldering, brazing, a combination of these, or a
number of other methods.
[0135] Upon drying, this embodiment of the endoluminal embolic
filter is ready for testing.
[0136] Various illustrative examples of the invention have been
described in detail. In addition, however, many modifications and
changes can be made to these examples without departing from the
nature and spirit of the invention.
* * * * *