U.S. patent application number 16/168639 was filed with the patent office on 2019-05-02 for devices and methods for percutaneous tissue removal.
This patent application is currently assigned to ANGIOWORKS MEDICAL, B.V.. The applicant listed for this patent is ANGIOWORKS MEDICAL, B.V.. Invention is credited to Ben-Ami Avneri, Itzhak Avneri, Shahar Avneri.
Application Number | 20190125396 16/168639 |
Document ID | / |
Family ID | 48044243 |
Filed Date | 2019-05-02 |
![](/patent/app/20190125396/US20190125396A1-20190502-D00000.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00001.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00002.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00003.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00004.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00005.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00006.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00007.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00008.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00009.png)
![](/patent/app/20190125396/US20190125396A1-20190502-D00010.png)
View All Diagrams
United States Patent
Application |
20190125396 |
Kind Code |
A1 |
Avneri; Ben-Ami ; et
al. |
May 2, 2019 |
DEVICES AND METHODS FOR PERCUTANEOUS TISSUE REMOVAL
Abstract
Devices and methods are provided for percutaneously treating
atherosclerotic plaques within blood vessels. Atherosclerotic
plaques cause significant morbidity and mortality by narrowing the
arteries, which adversely affects blood flow, and by acting as a
source for thrombi and emboli thus causing acute organ ischemia.
Current treatments include open surgery with its inherent
drawbacks, and stenting, which is less invasive but leaves the
plaque material in the artery, which promotes restenosis. The
present invention combines the advantages of both approaches. In
general, the invention provides tools that enable percutaneously
dissecting the plaque from the arterial wall and removing it from
the body.
Inventors: |
Avneri; Ben-Ami; (Moshav
Udim, IL) ; Avneri; Shahar; (Herzliya, IL) ;
Avneri; Itzhak; (Tel Aviv-Yafo, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ANGIOWORKS MEDICAL, B.V. |
Amsterdam |
|
NL |
|
|
Assignee: |
ANGIOWORKS MEDICAL, B.V.
AMSTERDAM
NL
|
Family ID: |
48044243 |
Appl. No.: |
16/168639 |
Filed: |
October 23, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14349920 |
Apr 4, 2014 |
10149697 |
|
|
PCT/IB2012/002847 |
Oct 4, 2012 |
|
|
|
16168639 |
|
|
|
|
61542901 |
Oct 4, 2011 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2017/320044
20130101; A61M 2025/0197 20130101; A61B 17/32037 20130101; A61B
2017/2215 20130101; A61B 2017/22052 20130101; A61B 17/320758
20130101; A61B 2017/00778 20130101; A61B 2017/22095 20130101; A61B
2017/2212 20130101; A61B 2017/320766 20130101; A61B 2017/22069
20130101; A61B 2017/320741 20130101; A61B 17/320725 20130101; A61B
2017/22061 20130101 |
International
Class: |
A61B 17/3207 20060101
A61B017/3207; A61B 17/3203 20060101 A61B017/3203 |
Claims
1-47. (canceled)
48. A device for percutaneous endarterectomy comprising: a catheter
having a lumen; one or more guidewires for threading through a
subintimal space of an artery, wherein the guidewires pass through
the lumen of the catheter; and an expandable separator device
comprising a hollow cylinder folded onto an elongated member,
wherein the separator when deployed assumes a cylindrical shape
with an overlap of both ends over a slit.
49. The device of claim 48 wherein the expansion of the separator
device separates a plaque from the arterial wall.
50. The device of claim 48 further comprising a cutting tool.
51. The device of claim 48 further comprising a grinder mounted on
a distal end of the catheter.
52. The device of claim 48 further comprising a grinder deployable
through the lumen of the catheter.
53-58. (canceled)
59. A device for inserting one or more guidewires into a subintimal
space of an artery comprising: a catheter having a lumen, a distal
end and a tip at the distal end; a pushing element at the tip of
said catheter; a balloon proximal to said pushing element; and one
or more guidewire catheters adjacent and parallel to said catheter,
said guidewire catheter passing over balloon and configured to
assume an orientation essentially parallel to longitudinal axis of
distal catheter or up to approximately 5 degrees outward of said
axis.
60. The device of claim 59, wherein said pushing element is a
balloon.
61. The device of claim 60, wherein said balloon is moveable
relative to said catheter.
62. The device of claim 59, wherein pushing element comprises an
expandable metal element.
63. A method for inserting one or more guidewires into subintimal
space, comprising identifying a lesion, bringing the device of 59
proximate to lesion, inflating proximal balloon, applying tension
by the pushing element, pushing guidewire forward into subintimal
space.
64. The method of claim 63 further comprising application of
suction on the area between the proximal and distal balloon prior
to the pushing the guidewire into subintimal space.
65. The method of claim 63 further comprising verification of
guidewire insertion into subintimal space by use of
angiography.
66. A method for removal of a plaque comprising inserting one or
more guidewires using the device of claim 59 and rotating the one
or more guidewires around the plaque, first forward until the one
or more guidewires re-enter the lumen and then backwards to remove
the plaque.
67. The device of claim 48 wherein the expandable separator further
comprises an inflatable balloon constructed of multiple
longitudinal chambers having a trapezoid cross-section and
connected to each other side by side.
68. The device of claim 48 wherein the guidewire is configured to
extend through a lumen of the artery on the proximal side and
distal side of a lesion and is configured to extend through the
subintimal space along the length of the lesion.
69. The device of claim 48 further comprising one or more markers,
the one or more markers configured to ascertain the orientation of
the device.
70. The device of claim 48 wherein the expandable separator further
comprises transverse longitudinal strips, each having a slight
curvature, such that when inflated, the device assumes a flat shape
with only slight radius of curvature.
71. The device of claim 48 wherein the expandable separator further
comprises multiple arched wires stemming off both sides of a
central longitudinal spine, and a sheath covering the arched wires,
wherein the sheath is configured to hold the arched wires flat
adjacent to the spine in an undeployed position.
72. The device of claim 71 wherein the arched wires are formed of
nitinol.
73. A method of percutaneous endarterectomy comprising: (a)
accessing an artery having an atherosclerotic plaque nearby the
plaque with a device comprising: a shaft configured to pass through
the lumen of a catheter, having a distal end, and one or more
expandable fingers having a proximal and distal end with the
proximal end of the one or more fingers attached to the distal end
of the shaft, wherein the fingers are configured to remove an
atherosclerotic plaque by peeling the plaque at the subintimal
space without performing an incision into the subintimal space and
without use of a blade, wherein the distal end of the expandable
fingers when expanded is substantially parallel to the shaft; (b)
peeling the plaque at the subintimal space without performing an
incision into the subintimal space and without use of a blade; (c)
separating the plaque from the arterial wall around its
circumference and along its length; (d) cutting the intima
connecting the distal part of the plaque to the arterial wall; and
(e) locally treating the exposed media after cutting by
instillation of endothelial progenitor cells, stem cells, other
cells or substances.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/349,920 filed on Apr. 4, 2014, which is a U.S. National
Phase Application of International Application No.
PCT/IB2012/002847, which has an international filing date of Oct.
4, 2012, and which claims priority to U.S. Provisional Application
No. 61/542,901, filed Oct. 4, 2011, the disclosures of which are
incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to devices and methods for
percutaneously treating atherosclerotic plaques within blood
vessels.
BACKGROUND OF INVENTION
[0003] The normal human artery is composed of three main layers.
The innermost layer lining the artery, in contact with the blood,
is the intima. This is a single cell layer of endothelial cells,
which among other functions regulates vascular tone, platelet
activation and thrombus formation, monocyte adhesion and
inflammation and vascular remodeling. The media--the middle layer,
consists of several layers of smooth muscle cells and elastic
fibers. The outermost layer is the adventitia, which is mainly
composed of connective tissue containing small blood vessels and
nerves.
[0004] Atherosclerosis is one of the major causes of cardiovascular
cerebrovascular and peripheral vascular morbidity and mortality. It
is a disease of large and medium-sized muscular arteries, which is
characterized by the formation of discrete lesions called
atherosclerotic plaques, or atheromas, thought to be caused by
injury to the endothelium. An atheroma is a buildup of lipids,
cholesterol, calcium, and cellular debris within the intima of the
vessel wall. Atherosclerotic buildup also results in vascular
remodeling, acute and chronic luminal obstruction, abnormalities of
blood flow and diminished oxygen supply to target organs.
[0005] A complex and incompletely understood interaction is
observed between the critical cellular elements of the
atherosclerotic lesion. These cellular elements include endothelial
cells, smooth muscle cells, platelets, and leukocytes.
[0006] The presence of risk factors accelerates the rate of
development of atherosclerosis. The main risk factors for the
development and progression of atherosclerosis include
hyperlipidemia and dyslipidemia, hypertension, cigarette
habituation, air pollution, diabetes mellitus, older age, male sex,
family history of premature CAD, obesity and physical inactivity.
Additional risk factors associated with atherosclerosis include
various metabolic diseases, autoimmune diseases, chronic kidney
disease, and depression.
[0007] Manifestations of atherosclerotic disease depend on the
affected organs and the type of lesions. Chronically narrowed
arteries give rise to symptoms of insufficient blood flow such as
angina pectoris (chest pain during exertion), intermittent
claudication (leg pain during exertion), and chronic leg ulcers.
Acute events can occur as a result as of plaque rupture and
thrombosis, which might totally clog the artery as in most cases of
acute myocardial infarction (heart attack), or as a result of
distal embolization of plaque fragments, as in many cases of
stroke.
[0008] Treatment of atherosclerosis depends on many factors
including the location of symptomatic lesions, the severity of
symptoms, and their dynamics.
[0009] Acute obstruction events usually require acute intervention.
For acute coronary events, treatment is urgent percutaneous
angioplasty (balloon dilation of the obstructed artery) and
stenting. Depending on the time from the beginning of symptoms,
acute ischemic stroke is sometimes treated urgently by percutaneous
mechanical removal of the obstruction or injection of compounds
that lyse it (tPA, streptokinase), but in many such cases treatment
will only focus on the prevention of future events. Acute limb
ischemia is also treated by urgent revascularization, either
percutaneous or surgical.
[0010] The treatment of chronic obstruction is usually a
combination of medical therapy and an interventional procedure.
[0011] Medical treatment may include anti platelet agents such as
Aspirin, anti-coagulants such as Coumadin, Statins, which decrease
cholesterol levels and stabilize plaques, and more.
[0012] Interventional procedures may be surgical or percutaneous
and are aimed at revascularization of the target organs and removal
of a potential source of emboli, if present.
[0013] Surgical treatments include bypass surgery, more commonly
used for coronary and lower limb arteries, and endarterectomy,
which is used for limb and carotid arteries, and involves opening
the artery and removing the plaque along with the intima.
Obviously, the disadvantage of surgery is its highly invasive
nature, the need for anesthesia, and the pain and stress involved
which make it unsuitable for certain patients.
[0014] Percutaneous procedures enable treating the lesions using
long catheters inserted to the arteries at a distant point such as
the groin arteries. The most common of these is placement of a
stent, a metal structure which is inserted to the artery in a
closed state and expanded within the lesion so as to keep the lumen
patent. This can be done with or without balloon angioplasty
(inflation of a balloon in the lesion to enlarge the lumen prior to
or following stent placement). The main disadvantage of angioplasty
and stenting is that the plaque remains in the artery. This has
several deleterious consequences. First--in carotid stenting, many
of the post stenting strokes are caused not during the procedure,
but after it, and are probably related to plaque material squeezing
through the cells of the stent and embolizing to the brain (a
phenomenon known as the "mashed potato effect"). Second--in many
cases the plaque encroaches on the stent and does not enable
attainment of a normal vascular lumen. This in turn affects flow
dynamics and shear stress, which may enhance atherogenesis and
cause restenosis. Third--the plaque material itself contains many
inflammatory and prothrombotic substances. This may be the reason
for the high rate of restenosis experienced after stenting.
[0015] In view of the disadvantages of surgery and of stenting, and
for treating heavily calcified lesions, novel procedures have been
developed that attempt to remove the plaque via a percutaneous
route. This type of procedure is termed percutaneous atherectomy,
and utilizes some form of ablation device that removes plaque from
within the lumen. Examples of such devices based on mechanical
grinding include the SILVERHAWK directional atherectomy device
(Covidien), the ROTABLATOR rotational atherectomy device (Boston
Scientific), the JETSTREAM NAVITUS (Pathway Medical Technologies).
Other systems use different forms of energy for removing plaque
material such as in laser atherectomy.
[0016] The two major drawbacks of these devices are:
(1) It is impossible to know exactly how much plaque to remove--too
much will injure the artery with possible rupture or dissection in
the wall, too little will leave a significant amount of atheroma.
Angiography is not accurate enough for this purpose, ultrasound is
being incorporated in such systems but will never allow as accurate
a result as that achieved with endarterectomy. (2) Its fibrous cap
having been removed, the atheroma with its deleterious contents is
left exposed to the blood flow.
[0017] Two other methods worthy of mention are subintimal
angioplasty and remote endarterectomy. Although good results were
reported with both methods, they require high technical
proficiency, have a long learning curve, and have therefore not
gained much acceptance in the medical community.
[0018] Subintimal angioplasty (also known as the Bolia technique)
is a percutaneous procedure developed for treating chronic total
occlusions (CTOs), in which the obstruction of the lumen is
complete, and the system cannot traverse the lesion. In these
cases, a guidewire is directed into the subintimal space between
the intima and the media of the arterial wall, and passed across
the lesion until it re-enters the lumen beyond it. Angioplasty and
stenting is then performed in this new artificial channel within
the arterial wall. As the atheroma is still adjacent to the stent,
the disadvantages mentioned above for regular stenting apply here
as well.
[0019] Remote endarterectomy is an open vascular procedure
performed on the arteries of the thigh, and mainly used to remove
long, severe plaques. The artery is surgically exposed and cut
open, and the dissection plane between the intima and media is
identified. Special tools for separating the plaque from the
arterial wall are inserted around the "core" which is subsequently
removed. This procedure is by definition a surgical one and the
tools are not appropriate for percutaneous use. Results of this
procedure are very good compared to other treatment modalities, and
advantages include decreased morbidity and shorter hospital stays
compared to surgery, preservation of bypass options, and decreased
incidence of limb-threatening ischemia when a remote endarterectomy
fails.
[0020] It is clear from the above, that percutaneous procedures and
devices enabling subintimal removal of atherosclerotic plaques
could provide great advantages over current practice, by combining
the accuracy of surgical endarterectomy with the benefits of
minimally invasive procedures. The aim of the current invention is
to describe such a solution, which will also be simple, safe, and
effective.
SUMMARY OF INVENTION
[0021] The invention includes various solutions to the removal of
atherosclerotic plaque from arteries. The apparatus and methods
include use of the natural dissection plane between the plaque and
the media of the artery.
[0022] Embodiments of the present invention include devices and
methods removal of atherosclerotic plaque from arteries, in
particular for percutaneous endarterectomy.
[0023] One embodiment of the invention is a device for percutaneous
endarterectomy including: a shaft configured to pass through the
lumen of a catheter, having a distal end; and one or more
expandable fingers having a proximal and distal end with the
proximal end of the one or more fingers attached to the distal end
of the shaft. In that embodiment, the fingers are configured to
remove an atherosclerotic plaque by peeling the plaque at the
subintimal space without performing an incision into the intimal
space and without use of a blade. Furthermore, optionally, the
finger may be configured so that radial force applied by the
fingers decrease going from the proximal to the distal end of the
tip relative to the plaque.
[0024] The device may further include a catheter having a lumen and
a distal end configured so that the shaft passes through the lumen
of the catheter.
[0025] This embodiment of the invention may have various other
features including but not limited to one or more of the following:
a) the one or more fingers are connected to each other by one or
more spokes; b) a distal end of the one or more expandable fingers,
when expanded, are substantially parallel to the shaft; c) the one
or more fingers are self-expanding; d) the one or more fingers
include a plurality of fingers to surround the shaft; e) the one or
more fingers include a substantially cylindrical formation when
expanded; f) the one or more fingers include a substantially
conical formation when expanded; g) the one or more fingers are
elongated and form a ribbon-shaped configuration; h) the one or
more fingers are each connected to a spoke, each spoke is connected
to a rod and the shaft includes a lumen through which the rod may
pass; i) the one or more fingers have a guidewire for passing a
guidewire therethrough; j) the one or more fingers are held in a
position relative to the shaft by a spoke; k) the one or more
fingers are held in a position substantially parallel to the shaft;
l) the one or more fingers are substantially straight; m) the one
or more fingers are substantially curved; n) the one or more
fingers have a bent end; o) the one or more fingers have a
transverse cross-section with a leading end and an trailing end,
wherein the leading end is smaller than the trailing end; p) the
one or more fingers has a longitudinal length and a cross-section
size of the one or more fingers along the longitudinal length
varies; q) the one or more fingers may have the same or different
cross-sectional shapes; r) the one or more fingers include a loop;
s) the one or more fingers are petal-shaped; and/or t) the one or
more fingers include a plurality of fingers surrounding the shaft
and the plurality of fingers, when expanded, are spaced apart from
each other. The fingers may also be rotatable.
[0026] Another embodiment of the invention is a device for
percutaneous endarterectomy including: a rod; a shaft having a
lumen and a distal end for passing over the rod; a catheter having
a lumen and a distal end for passing over the shaft; one or more
expandable and rotatable fingers having a proximal and distal end
with the proximal end of the one or more fingers attached to the
distal end of the shaft, having an exterior surface facing the
artery and an interior surface facing the rod; and one or more
spokes connecting the rod to the one or more expandable fingers on
the interior surface whereby the fingers are controllable by the
rod through the one or more spokes, whereby the fingers are
configured to remove an atherosclerotic plaque by peeling the
plaque at the subintimal space without performing an incision into
the subintimal space and without use of a blade, whereby the distal
end of the expandable fingers when expanded is parallel to the
shaft, and whereby the fingers are configured to be advanced
forwards and/or backwards.
[0027] In one embodiment, the fingers are configured so that radial
force applied by the fingers decrease going from the proximal to
the distal end of the tip relative to the plaque. In another
embodiment, the fingers further include a centerline running
longitudinally from the distal end of the fingers to the proximal
end of the fingers. Optionally, the fingers also further include a
marker at the distal end of the centerline. The fingers may be
radially expandable.
[0028] Two or more rows of spokes may connect the rod to the one or
more fingers. In one embodiment, the two or more rows of spokes are
parallel to each other. In another embodiment, the two or more rows
of spokes create a parallelogram configuration with two sides of
the parallelogram formed by the rows of spokes, one side formed by
the shaft and the other side formed by the one or more fingers.
[0029] In any of these embodiments, the distal tip of the fingers
may be sharp and the distal end of the fingers is sufficient to
find the edge of the plaque without cutting the media or
adventitia. Alternatively, in any of these embodiments, the distal
end of the fingers is blunt and sufficient to find the edge of the
plaque without cutting the media or adventitia.
[0030] The device for percutaneous endarterectomy of the invention
may further include additional components such as e.g. a dissector,
cutting tool and/or rotatably mounted jets.
[0031] The dissector may include expandable loops configured to
separate the plaque from the arterial wall around its circumference
and along its whole length. In one embodiment, the dissector is
configured for passing through the lumen of a catheter. In another
embodiment, a cutting tool located at the tip of the dissector
tool. The dissector tool may also include one or more jets.
[0032] In addition, when jets are included the device includes
monitoring of pressure. Thus, in one embodiment, the fluid pressure
of liquid injected by the one or more jets and the net volume of
liquid injected is monitored. In another embodiment, the pressure
inside the catheter is monitored. In yet another embodiment, the
pressure inside the artery is monitored.
[0033] In one embodiment, the device includes a cutting tool. A
suitable cutting tool is a cutting tool having one or more
deployable angled blades at the tip of the cutting tool. In one
embodiment, the cutting tool is configured so that the deployable
angled blades excise the plaque.
[0034] In addition to the cutting tool, the device may also include
a funnel shaped catheter tip. This funnel shaped catheter tip may
be advanced around the plaque to collect plaque after cutting.
[0035] In another embodiment, the devices also include one or more
rotatably mounted jets. In one embodiment, the jets are configured
to sever the plaque from the vascular walls.
[0036] The devices may also contain a balloon and/or cage
configured to separate the plaque.
[0037] Another embodiment of the invention is a device for
percutaneous endarterectomy including: a shaft; a catheter having a
lumen and a distal end for passing over the shaft; one or more
expandable and rotatable retrograde fingers having a proximal and
distal end with the proximal end of the one or more fingers
attached to the distal end of the shaft wherein the distal end of
the fingers faces the proximal end of the catheter; a slideable
sheath positioned on the distal end of the catheter configured to
cover the one or more rotatable fingers, wherein the fingers are
configured to remove an atherosclerotic plaque by peeling the
plaque at the subintimal space without performing an incision into
the subintimal space and without use of a blade. This device may be
configured so that sliding of the sheath expands the fingers. In
one embodiment, the fingers remove the plaque by a backward
motion.
[0038] The devices of the invention may be used in methods of
percutaneous endarterectomy. Thus, other embodiments of the
invention are method of percutaneous endarterectomy which use of
the devices of the invention, whereby an atherosclerotic plaque is
removed by peeling the plaque at the subintimal space without
performing an incision into the subintimal space and without use of
a blade.
[0039] Another embodiment of the invention is a method of
percutaneous endarterectomy including: accessing an artery having
an atherosclerotic plaque nearby the plaque with a device
including: a shaft configured to pass through the lumen of a
catheter, having a distal end, and one or more expandable fingers
having a proximal and distal end with the proximal end of the one
or more fingers attached to the distal end of the shaft, wherein
the fingers are configured to remove an atherosclerotic plaque by
peeling the plaque at the subintimal space without performing an
incision into the subintimal space and without use of a blade,
wherein the distal end of the expandable fingers when expanded is
substantially parallel to the shaft; peeling the plaque at the
subintimal space without performing an incision into the subintimal
space and without use of a blade; and separating the plaque from
the arterial wall around its circumference and along its
length.
[0040] The method may further include cutting the intima connecting
the distal part of the plaque to the arterial wall and optionally
local treatment of the exposed media after cutting by instillation
of endothelial progenitor cells, stem cells, other cells, or
substances. In one embodiment of the method, the step of cutting
comprises use of a dissection tool having one or more deployable
angled blades. Via use of the angled blades, the step of cutting my
include cutting the intima and excises the plaque without leaving
an intimal flap. The method may further include removal of the cut
plaque (via e.g. use of a funnel shaped catheter tip) and removal
of the device. The step of separating the plaque may include use of
a dissector. The method may optionally include the step of locating
the plaque prior to peeling. In one embodiment, step of locating
includes moving the fingers of the device along the subintimal
space to locate the plaque.
[0041] Another embodiment of the invention is a device for entry
into subintimal space having: a rotatable shaft having a metal
strip attached to the distal tip of the shaft, wherein the distal
end of the metal strip curves; one or more inclined blades attached
to the distal end of the metal strip; a removable sheath for
sliding over the rotatable shaft and for covering the one or more
inclined blades; a catheter having a lumen and a distal end for
passing over the shaft; and one or more balloons disposed towards
the distal end of the catheter; wherein the device is configured so
that rotation of the shaft rotates the blades which in turn cuts
through the intima, wherein the sheath is configured to be
removable during use of the device.
[0042] Yet another embodiment of the invention is a device for
percutaneous endarterectomy including: a catheter having a lumen;
one or more guidewires for threading through the subintimal space,
wherein the guidewires pass through the lumen of the catheter; an
expandable separator device comprising a hollow cylinder folded
onto an elongated member, wherein the separator when deployed
assumes a cylindrical shape with an overlap of both ends over the
slit. In one embodiment, the expansion of the separator device
separates the plaque from the arterial wall. The device may also
further include a cutting tool.
[0043] In certain embodiments, the devices of the invention include
a grinder. The grinder may be mounted on the distal end of the
catheter. Alternatively, the grinder may be deployable through the
lumen of the catheter.
[0044] Yet another embodiment of the invention is a device for
percutaneous endarterectomy including: a catheter having a lumen
and a distal end; one or more guidewires for threading through the
subintimal space, wherein the guidewires pass through the lumen of
the catheter; a shaft having a distal end passing through the
catheter lumen; one or more expandable loop shaped wings having a
distal edge and a distal tip, wherein the loop shaped wings are
attached to the shaft; a removable cap on the distal end of the
catheter, whereby the device is configured so that removal of the
cap causes expansion of the wings. The cap may include a tip and a
shaft, such that the shaft of the cap passes through the catheter
lumen. The device may also include a web covering the one or more
wings. In one embodiment, the web is configured to be an emboli
protection device. Additionally, the device may further include a
cutting tool. In one embodiment, the one or more wings are
configured to anchor the distal intima and to thereby enable
cutting without leaving an intimal flap.
[0045] Yet another embodiment of the invention is a device for
inserting one or more guidewires into a subintimal space of an
artery including: a catheter having a lumen, a distal end and a tip
at the distal end; a pushing element at the tip of said catheter; a
balloon proximal to said pushing element; and one or more guidewire
catheters adjacent and parallel to said catheter, said guidewire
catheter passing over balloon and configured to assume an
orientation essentially parallel to longitudinal axis of distal
catheter or up to approximately 5 degrees outward of said axis. The
pushing element may be a balloon or include an expandable metal
element. In one embodiment, the balloon is moveable relative to
said catheter.
[0046] This device for inserting one or more guidewires into a
subintimal space of an artery may be used in a method for inserting
one or more guidewires into subintimal space including identifying
a lesion, bringing the device proximate to lesion, inflating
proximal balloon, applying tension by the pushing element, and
pushing guidewire forward into subintimal space. The method may
further include one or more of (a) application of suction on the
area between the proximal and distal balloon prior to the pushing
the guidewire into subintimal space and (b) verification of
guidewire insertion into subintimal space by use of
angiography.
[0047] In another embodiment, this device for inserting one or more
guidewires into a subintimal space of an artery may be used in a
method for removal of a plaque including inserting one or more
guidewires using the device and rotating the one or more guidewires
around the plaque, first forward until the one or more guidewires
re-enter the lumen and then backwards to remove the plaque.
[0048] Additional features, advantages, and embodiments of the
invention are set forth or apparent from consideration of the
following detailed description, drawings and claims. Moreover, it
is to be understood that both the foregoing summary of the
invention and the following detailed description are exemplary and
intended to provide further explanation without limiting the scope
of the invention as claimed.
BRIEF DESCRIPTION OF THE FIGURES
[0049] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate preferred
embodiments of the invention and together with the detailed
description serve to explain the principles of the invention. In
the drawings:
[0050] FIGS. 1A-B show two different common structures of the edge
of an atherosclerotic plaque in an artery.
[0051] FIGS. 2A-F show embodiments of edger tools in accordance
with the principles of the invention.
[0052] FIGS. 3A-3E show stages of use of an edger tool in
accordance with the principles of one embodiment of the
invention.
[0053] FIGS. 4A-B show the angiographic appearance of successful
and failed edging.
[0054] FIGS. 5A-C show embodiments of dissector tools in accordance
with the principles of the invention
[0055] FIGS. 6A-B show use of one embodiment dissector tool in
accordance with the principles of the invention.
[0056] FIGS. 7A-E show embodiments of a distal intimal cutting tool
in accordance with the principles of the invention.
[0057] FIG. 8A shows use of one embodiment of a distal intimal
cutting tool in accordance with the principles of the invention.
FIG. 8B shows a detail from FIG. 8A, which shows use of one
embodiment of a distal intimal cutting tool in accordance with the
principles of the invention.
[0058] FIGS. 9A-B show cross-sectional views of two different
embodiments of anchoring balloons for guiding catheter in
accordance with the principles of the invention.
[0059] FIGS. 10AA, 10BB, 10CC and 10A-F show various overall shapes
of a distal end of a fingered shaft (edger) from both side and end
views in accordance with the principles of the invention.
[0060] FIGS. 10G-K show various cross-sectional shapes of a finger
of the fingered shaft (edger) in accordance with the principles of
the invention.
[0061] FIG. 11 shows use of a fingered shaft (edger) in accordance
with the principles of the invention.
[0062] FIG. 12 shows use of a fingered shaft (edger) with saline
jet in accordance with the principles of the invention.
[0063] FIG. 13A-C show cross-sectional view of the finger and
showing a saline jet exiting finger of the fingered shaft in
accordance with the principles of the invention.
[0064] FIG. 14 shows use of edging and dissection tool employing
saline jet and no fingers in accordance with the principles of the
invention.
[0065] FIG. 15 shows an alternative embodiment of an edger tool
finger in accordance with the principles of the invention.
[0066] FIG. 16A-B show an embodiment of a combined edger and
dissector tool in accordance with the principles of the
invention.
[0067] FIG. 17 shows an embodiment of a cutting tool in accordance
with the principles of the invention.
[0068] FIG. 18A-C show an embodiment of a dissector tool in three
dimensional and longitudinal sections.
[0069] FIG. 18D-F show longitudinal sections of alternative
embodiments of dissector tools.
[0070] FIG. 19A-B show alternative embodiments of distal intimal
cutting tools.
[0071] FIG. 20A-D show various embodiments of a distal tip of
dissector tool loops.
[0072] FIG. 21A-B show an embodiment of a medial plaque remover
device.
[0073] FIG. 22A-F shows stages of use of a medial plaque remover
device.
[0074] FIG. 23 shows an embodiment of a medial plaque remover
device in its inflated position.
[0075] FIG. 24 shows a different embodiment of a medial plaque
remover device in its inflated position.
[0076] FIGS. 25A-C show an embodiment of a metal medial plaque
remover device from different views.
[0077] FIG. 26A-C show embodiments of subintimal wire insertion
devices.
[0078] FIG. 27A-C show additional embodiments of subintimal wire
insertion devices.
[0079] FIG. 28 shows an embodiment of a media treatment catheter
device.
[0080] FIG. 29 shows an embodiment of a distal intima cutting
tool.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0081] The invention includes various solutions to the removal of
atherosclerotic plaque from arteries. This invention includes
methods and devices for performing percutaneous endarterectomy
(i.e. removal of atherosclerotic plaques from arteries via a e.g. a
catheter). The devices and methods may release plaque at its edge
and peel away the plaque naturally, preferably, for example, along
the subintimal space. All may be preferably based on the same
principle of utilizing the natural dissection plane, which in the
subintimal space, exists between the plaque and the media of the
artery, for removing the plaque with a percutaneous tool.
[0082] As known to those skilled in the art, the subintimal space
is a potential space where a false lumen could form if blood flow
were to enter it through an intimal tear and cause an arterial
dissection.
[0083] It is the same space used for passing the guidewire and
creating an artificial extraluminal route in subintimal angioplasty
procedures (the Bolia technique), and where the plaque is usually
separated from the arterial wall in open endarterectomy operations.
A recent article reports a case in which an occluded artery was
endarterectomised two months after a subintimal angioplasty was
performed on it, and histological cuts demonstrated that "the
subintimal track had been formed between the internal elastic
lamina and the atherosclerotic plaque at most levels." Scholtes et
al., "Subintimal Angioplasty Track of the Superficial Femoral
Artery: A Histological Analysis", Circ Cardiovasc Interv.; 2012;
5:e6-e.8. It is therefore thought that subintimal angioplasty is
not a random extraluminal revascularization procedure but creates
subintimal passage in the form of a dissection between the
atherosclerotic plaque and the media of the artery." Scholtes et
al.
[0084] In this invention, the plane between the media and intima is
utilized because it may be the pathway of least resistance around
the plaque. As such, the guidewire in subintimal angioplasty
procedures usually finds its way into the subintimal space quite
naturally. The current invention describes additional ways in which
to enter this space.
[0085] FIGS. 1A-B show two different common structures of the edge
of an atherosclerotic plaque in an artery. With reference to FIG.
1A the artery comprises normal media 10 and normal intima 11. The
atherosclerotic plaque 12 in the artery is shown in both FIG. 1A
and FIG. 1B. FIG. 1B also illustrates the atherosclerotic
(thickened) intima 13.
[0086] Two general directions are described, which differ in the
aspect from which the plaque is approached: its edge or the medial
aspect.
[0087] "Plaque's edge," as used herein refers to the border of the
occluding lesion, whether proximal or distal. In some cases, as
shown in FIG. 1A, the lesion may have a distinct, abrupt border
between a normal or essentially normal area and a stenotic area,
wherein an actual "step" in thickness of the intima is present. In
other cases, this border may be less distinct, with a gradual
transition or tapering between the stenotic and patent areas of the
artery (FIG. 1B). In such cases, the "edge" would be a location
initially chosen by the physician, from which the stenosis is
deemed of no clinical significance.
[0088] "Medial aspect" refers to an approach to the plaque
beginning with passage of a device in the subintimal space
throughout the length of the lesion.
[0089] All the described procedures and tools are preferably used
after deployment of an embolic protection device in the artery.
Alternatively, by way of example, the treated area may be isolated
by inflating balloons at one or both of its ends.
[0090] The tools and methods described herein may be used with
slight modifications either in an antegrade or in a retrograde
fashion. Antegrade use refers to advancement around the plaque
while the device is being pushed forward. This has the advantage of
not necessitating traversing of the lesion before initiation of
treatment; hence, it is appropriate for the treatment of CTO
lesions (Chronic Total Occlusions). The disadvantage is that
pushing the device forward may be more difficult technically than
pulling it. Retrograde use refers to advancement around the plaque
while the device is being pulled backward. This requires that the
device be passed through the lesion prior to initiation of
treatment. Only then can it be deployed and pulled back. The main
disadvantage is that the lumen through some lesions may be so
stenotic as to prevent passage of the catheter, in which case this
approach cannot be used. On the other hand, this approach may be
more suitable for lesions at bifurcations.
[0091] After placing the treatment catheter at the vicinity of the
lesion, demonstrating it, optionally placing any of the many
available embolization protection devices, and anchoring the
treatment catheter, treatment may follow these stages:
1. Access into the subintimal space. This entails passage of an
instrument into the subintimal space ("SIS"), and in some cases
initial separation of the plaque, a process herein referred to as
"edging," which may be performed using an "edger" tool. Such
separation is intended to enable further separation of the plaque
from the arterial wall, herein referred to as "dissection." 2.
Dissection of the plaque. This entails separation of the plaque
from the arterial wall around its circumference and along its whole
length. Dissection may be performed using a specialized "dissector"
tool, or in some embodiments with the edger tool. 3. Distal
cutting. After the plaque was separated all around, the intima
connecting the distal part of the plaque to the arterial wall may
be cut. 4. Closure. A device enclosing the plaque is generally
closed so as to contain the plaque and its fragments. 5. Removal.
The device with the plaque in it is removed from the artery. 6.
Medial surface treatment. Optionally, treatment may be applied that
enhances arterial healing and attenuates thrombogenicity and
platelet adhesion to the exposed medial surface. Such treatment may
consist of re-endothelialization therapy by e.g. instillation of
endothelial progenitor cells, stem cells, or other cells or
substances. Typically, such treatment will be applied using a
specially designed balloon catheter system which keeps the
cells/substance in contact with the arterial wall while at the same
time allowing continuous blood flow through the treated area.
[0092] The tools and methods described herein are aimed at removal
of the plaque as a whole, preferably in one piece. For example, the
exemplary devices and methods described herein provide for release
of the plaque, preferably at its edge, and peeling of the plaque. A
different approach is to use a grinder/macerator tool, which can
also be used along with certain aspects and embodiments of the
current invention. However, such a tool adds complexity, cost, and
danger to the system, and in addition, grinding the plaque releases
various deleterious thrombogenic and inflammatory substances into
the blood stream, hence the preference for removal of the plaque
without disintegrating it.
[0093] Most preferred embodiments of the invention are based on the
approach of attacking the plaque from its edge. In particular, the
devices and methods of the invention provide for release of the
plaque, such as through scraping and peeling of the plaque.
Preferably, this is done without making a cut into the intima
and/or media. Without radial cutting, grinding or abrading the
plaque as the primary removal technique, the plaque may be scraped
or edged away from the vessel wall to be peeled away along the
natural dissection plane. In one embodiment, a device, utilizing,
for example, fingers or projections, approaches the plaque from
inside the vessel to contact and/or engage the plaque with a
scraping action, for example, to find the way into the subintimal
space. With the scraping action, the plaque/intima layer separates
because the plaque/intima is naturally peeled away. The methods and
devices of the invention do not rely e.g. on radial cutting,
grinding, or abrasion and as such are much more gentle.
[0094] In a preferred embodiment, an edger tool is provided
including a tubular member from which end extend several elongated
radially expandable "fingers." An example of such tool based on an
umbrella like mechanism is shown in FIG. 2A-2E. FIG. 2A is a
three-dimensional depiction of edger 20 which is passed through
catheter 30. It includes of shaft 24 from which extend fingers 21.
Rod 25 extends through shaft 24 and is connected to each finger 21
by spoke 26. At centerlines 22 of fingers 21 near their edge may be
additionally installed radiopaque marker 23. A longitudinal section
of edger 20 in its open position is shown in FIG. 2B and in its
closed position in 2C. Fingers 21 may be formed of an elastic
material and pre-shaped in the open position, such that when pushed
out of guiding catheter 30 and in the absence of pulling resistance
by rod 25, the edger will open. In such case, release of rod 25
controls the degree of finger 21 radial expansion and open
diameter. Alternatively, finger 21 radial expansion may depend on
pushing rod 25 forward. In any case, following radial expansion,
fingers 21 assume a position essentially parallel to that of shaft
24 longitudinal axis (FIG. 2B).
[0095] A slightly different example of edger tool is shown in FIG.
2D-2F. This tool is similar to edger 20 but has additional spokes
intended to maintain the fingers' parallel position. More
particularly, FIG. 2D is a 3D depiction of edger 40 which is passed
through catheter 30. It includes shaft 44 from which extend fingers
41. Rod 45 extends through shaft 44 and is connected to each finger
41 by inner spoke 46 and a more distal outer spoke 47. Inner spoke
46 and outer spoke 47 are of the same length, and the distances
between their connection points on finger 41 and on rod 45 are also
equal, such that they form a parallelogram. At centerlines 42 of
fingers 41 near their edge may be additionally installed radiopaque
marker 43. A longitudinal section of edger 40 in its open position
is shown in FIG. 2E and in its closed position in 2F. Fingers 41
may be formed of an elastic material and pre-shaped in the open
position, such that when pushed out of guiding catheter 30 and in
the absence of pulling resistance by rod 45, the edger will open.
In such case, release of rod 45 controls the degree of finger 41
radial expansion and open diameter. Alternatively, finger 41 radial
expansion may depend on pushing rod 45 forward. In any case,
following radial expansion, fingers 41 assume a position
essentially parallel to that of shaft 44 longitudinal axis (FIG.
2E), which is maintained at any opening diameter due to the
parallelogram design.
[0096] In one embodiment, the fingers 41 are of the same length.
The fingers are designed so that radial force applied by the
fingers decrease going from the proximal to the distal end of the
tip (relative to the plaque). Thus, in one embodiment, the fingers
deliver more force on the proximal end of the finger and less force
on the distal end. In one embodiment, the tips of fingers are
parallel to the shaft so that they do not cut the artery and so
they are substantially in the direction of the dissection plane.
The fingers are also so configured that they are more rigid towards
the distal end and more flexible to the distal end. Furthermore,
the edges of the fingers may be blunt or rounded. Thus, in one
embodiment, the radius at the end of the fingers is not sharp,
rather it is blunt and sufficient to find the edge of the plaque
without cutting the intima. The fingers, in this configuration, may
be used to remove the plaque in a forward motion. In one
embodiment, the longitudinal sections of the fingers are parallel.
It is thought that less force on the distal end results in a device
that provides for a more gentle removal of the plaque and the
ability to find the natural separation of the plaque. The
embodiments shown and described herein are exemplary. For example,
the force differences can be achieved in a variety of ways
including structurally (via e.g. use of structural features such as
struts and guidewires or a changing cross-section) or functionally
(via e.g. use of a different materials).
[0097] Fingers 41 as shown in FIG. 2A have a thin configuration
that may be flat or curved as desired in accordance with the
principles of the invention. Although other configurations may be
used in accordance with the principles of the invention, for
example, the lateral and transverse cross-sections of finger 41 may
vary, and, further may vary, for example, as discussed in other
embodiments described herein. Finger cross-sections also are shown
in FIGS. 10G-K.
[0098] In another embodiment, the fingers may be sharp and the
fingers are configured to find the edge of the plaque without
radially cutting the intima. In another embodiment, due to the
lateral positioning of the edger relative to the plaque, the
fingers, may be relatively blunt, sharp or otherwise in accordance
with the principles of the invention to accomplish the scraping
and/or edging of the plaque so it may be removed along its natural
dissection line. The fingers of the edger tools in accordance with
the principles of the invention may be caused to probe along the
arterial wall to find the edge and/or natural line/plane of
dissection of the plaque. In one embodiment, the fingers press
gently against the arterial wall and gently scrape the plaque to
find the edge and/or natural separation. FIG. 2A-3E show the stages
of edger 40 use. More particularly FIG. 3A shows longitudinal
section of artery having inner diameter 15 with media 10 and plaque
12 at a distance 14 from tip of catheter 30, which is anchored by
balloon 31. FIG. 3B shows edger 40 in its closed position passed
through catheter 30. FIG. 3C further shows edger 40 in its open
position. FIG. 3D shows the above with edger 40 being advanced
towards plaque 12. FIG. 3E further shows fingers 41 separating
between media 10 and plaque 12. The distal portions of the fingers
may also be substantially parallel to the central axis of the
device e.g. pushing rod
[0099] In use, guiding catheter 30 is brought to the vicinity of
the target lesion 12 which is then demonstrated angiographically.
If possible, an embolization protection device is deployed. The
guiding catheter has a balloon 31 around its tip, which is inflated
to anchor the catheter with its tip at a distance 14 from the
plaque's edge, typically approximately 0.5-1 cm in a large
(approximately 6-8 mm) artery, but possibly as short as
approximately 1-5 mm in a small or medium (approximately 2-6 mm)
artery (FIG. 3A). Arterial diameter 15 at the plaque edge is
measured angiographically and an edger tool is chosen having an
open diameter at least approximately 10% larger than arterial
diameter 15. Edger 40 is deployed through guiding catheter 30 (FIG.
3B) and expanded such that its fingers are slightly pressed against
the arterial wall (FIG. 3C). This can be verified angiographically.
Edger 40 is then rotated along its longitudinal axis and advanced
towards lesion 12 (FIG. 3D). This separates the edge of plaque 12
from media 10, such that fingers 41 are in the SIS (FIG. 3E). The
normal medial layer of the arterial wall has much higher axial
flexibility (ultimate stretch greater than about 1.5) compared with
the normal intimal layer, and these differences are exaggerated
when comparing normal media to atherosclerotic intima in which both
axial and circumferential flexibility are reduced (ultimate axial
stretch of about 1.1-1.2). Calcified plaque elements are
essentially rigid with an ultimate stretch of approximately 1.02
(See Holzapfel A G et al., "Anisotropic Mechanical Properties of
Tissue Components in Human Atherosclerotic Plaques" Journal of
Biomechanical Engineering, 2004, 126; 657-665). These differences
in mechanical properties aid in the process of separation between
the layers by the edger tool, which applies both circumferential
and axial forces on all layers. The different response of each
layer to these forces creates shear forces between the layers,
which lead to their separation.
[0100] Optionally, verification of proper "edging" can be done
angiographically, as seen in FIG. 4A-4B. FIG. 4A shows a schematic
of an angiogram in case of successful edging. Edger 20 is shown
through catheter 30 with radiopaque marker at the tip of finger 21.
Filling defect 33 is seen between contrast material 32 and finger
21. FIG. 4B shows a schematic of an angiogram in case of
unsuccessful edging. Edger 20 is shown through catheter 30 with
radiopaque marker at the tip of finger 21. No filling defect 33 is
seen between contrast material 32 and finger 21. As shown in FIG.
4A, the correctly positioned fingers are demonstrated external to
the edge of the plaque, which is seen as a filling defect, whereas
in FIG. 4B, the fingers are internal to the plaque edge, which
means the edging was not successful.
[0101] At this stage of the procedure, a dissector tool is
introduced over the edger tool through the guiding catheter. An
example of a dissector made of looped metal (such as nitinol) wires
is shown in FIG. 5A-5C. More particularly, FIG. 5A shows dissector
50 made of wire loops 51, which may or may not be connected to each
other by connector 52. The distal most part of each loop is at its
centerline 53. FIG. 5B shows a similar dissector wherein each loop
51 is braided with the adjacent loop 51. FIG. 5C shows a possible
more intricate pattern of braiding in which several loops are
interlaced with each other.
[0102] The number of loops 51 in dissector 50 may vary between 2-8
but is typically 3-5. Loops may be completely separate as in 5A, or
every two adjacent wires may be connected to each other by a
connector 52. The braiding may be a simple one, involving only each
two adjacent wires as in FIG. 5B, or more intricate including
several loops as shown in FIG. 5C. Alternatively, such dissector
may be formed of laser cut metal sheets or tube.
[0103] FIG. 6A-6B show use of dissector 50. More particularly, FIG.
6A is a three dimensional depiction of dissector 50, which is seen
coming out of catheter 30, with its loop centerlines 53 over edger
20 finger centerlines 22. FIG. 6B shows a longitudinal section of
an artery with plaque 12, and catheter 30 anchored by balloon 31.
Dissector 50 is seen coming out of catheter 30 and being inserted
into the SIS over edger fingers 21.
[0104] In use, as the dissector is pushed forward out of the
guiding catheter (FIG. 6A), the user can rotate it to bring the
centers of the loops 53 in line with the edger finger centerlines
21. Thus, the edger serves as a guide for the dissector into the
SIS (FIG. 6B). Once the dissector loops pass the edger fingers, the
edger can be retracted and removed. Optionally, the interior of
guiding catheter 30 may be shaped with grooves that help align the
edger and dissector tools.
[0105] The dissector is then advanced in the SIS under angiographic
monitoring until it reaches the end of the lesion. Advancement of
the dissector is achieved by a combination of forward push and
rotation. The dissector loops will tend to expand as it is pushed
forward, pressing against the flexible media and away from the more
rigid plaque, which aids in the separation process.
[0106] Once dissector 50 passes lesion 12, dissector loop ends 53
might tear through intima 11 and enter the lumen without any action
on behalf of the user. Such automatic re-entry may be enhanced by
pre-shaping the dissector's nitinol loops with a curve towards the
center of the lumen. However, this type of unintended re-entry
carries a high chance of producing an intimal flap, which in turn
might cause an arterial dissection, a dangerous complication of
endarterectomy, which can lead to clogging of the artery,
thrombosis, aneurysm or perforation. If an intimal flap is observed
or suspected, it can be treated by placement of a stent over the
transition area between the endarterctomized artery and untreated
intima. In the current embodiment, in order to prevent the above,
the dissector loops are shaped with an outward curve to reduce
their tendency for re-entry. An intima cutting tool is provided as
part of the dissector To enable smooth re-entry. Such tool 60 is
shown in FIG. 7A-7E.
[0107] More particularly, FIGS. 7A & 7B are three-dimensional
depictions of intimal cutting tool 60 including blade 61 and guard
62, slideably held together by holder 63. FIG. 7A shows the closed
position of cutting tool 60 whereas FIG. 7B shows the open position
of cutting tool 60. FIG. 7C is an end view and FIG. 7D a side view
of cutting tool 60. FIG. 7E shows typical assembly of cutting tool
60 over centerline 53 of loop 51 of dissector 50. FIGS. 8A and 8B
show use of cutting tool 60 in a longitudinal section of an artery
with media 10, plaque 12 separated by dissector 50, with cutting
tool 60 over it, cutting through intima 11. A close-up view of the
re-entry area is shown, with blade 61 sliding over guard 62 and
loop centerline 53 of dissector 50, bending towards the lumen, and
cutting through intima 11, creating an incision in intima 11 having
an angle 64 with longitudinal axis of artery.
[0108] Intimal cutting tool 60 may be include two parallel metal
strips, a blade 61, and a guard 62, held together by holder 63.
Blade 61 has a sharp tip and side, whereas guard 62 has a rounded
tip and blunt sides. Blade 61 is also pre-shaped with an arch, such
that when slid forward over the guard, its sharp area is exposed
and it arches to the direction of the guard. The cutting tool is
typically attached to one of the dissector loop centerlines 53
(FIG. 7E). In use, when the dissector passes the lesion, the blade
61 is deployed (FIG. 8), penetrating through the intima in a sharp
angle 64. The whole dissector is then rotated along its
longitudinal axis such that the intima is cut all around the lumen,
without leaving an intimal flap. The blade is retracted.
[0109] The entire intimal core is now completely separated from the
arterial wall. The dissector is pulled backwards. This causes the
loops to lengthen and the dissector's diameter to decrease,
compressing the intimal core, and holding on to it. This enables
removal of the complete core with the dissector.
[0110] The above was a general description of a preferred
embodiment. Specific modifications of each stage and tool may be
employed to improve performance of the invention. Following are
some such modifications.
[0111] The anchoring balloon of the guiding catheter may be formed
as several separate balloons (FIG. 9A), or having several conduits
through it (FIG. 9B), to allow continuous blood flow across the
treatment area during the procedure. This may be essential when the
procedure is performed in areas that cannot tolerate cessation of
blood flow, for example in case of treating a carotid artery when
contralateral circulation is insufficient. Of course, in such a
case, a distal protection device would be crucial. FIG. 9A shows
catheter 30 surrounded by split balloons 34, and FIG. 9B shows a
balloon having conduits 35 through it.
[0112] In a different embodiment of the edger tool, referring
generally to FIGS. 10AA, 10BB and 10CC, the tool may include an
elongated member from which end at least one "finger" (FIGS. 10AA
& 10BB) but preferably three "fingers" (FIG. 10CC) or more
"fingers" project retrogradely. Radial expansion of these fingers
may be achieved by their being made of a shape memory alloy such as
nitinol, or by other means or ways such as an inflatable balloon.
Limitation of the radial expansion of the fingers for example by a
slideable external sheath enables control over the degree of
contact with the arterial wall and force applied to it. In one
embodiment, the edger tool complete with the sheath is deployed
through the guiding catheter which is anchored by the balloon. The
sheath may function to only open and close the tool. The fingers
are designed so that radial force applied by the fingers decrease
going from the proximal to the distal end (relative to the plaque).
In one embodiment, the fingers are parallel so that they do not cut
the artery and so the fingers extend substantially in the direction
of the dissection plane. The fingers are also so configured that
they are more rigid towards the distal end and more flexible to the
distal end. In another embodiment, the edges of the fingers may be
sharp and the fingers configured to find the edge of the plaque
without radially cutting the intima.
[0113] This "retrograde edger" tool is inserted through the guiding
catheter placed proximal to the lesion. This tool is intended to be
pulled back. It is passed beyond the lesion, deployed, then pulled
back. The guiding catheter is used as a "base station". The guiding
catheter is in place for passing any kind of tool and does not need
to be part of the various devices. The edger is passed through the
lesion until after its distal edge as seen on angiography. The
sheath is withdrawn to allow radial expansion of fingers, which
contact the arterial wall. The guiding catheter is away from the
tool (see FIG. 11)
[0114] More particularly, FIGS. 10AA and 10BB show an "edger" tool
generally shown by reference number 70. Edger tool 70 includes an
elongated member 71 with a distal end 72 terminating in a distal
tip 73. From elongated member 71 extends one finger 74 that extends
retrogradely. For example, as shown, distal tip 73 may extend in
one direction and a finger distal tip 78 may extend in another
direction, preferably, retrogradely relative to a direction of
distal tip 73. The relative positioning and direction of distal
tips 73 and 78 may vary depending upon the positioning of finger 74
radially and/or relative to shaft 71. Finger 74 may move relatively
freely and independently of shaft 71, in the embodiment shown, and
may expand in a generally radial direction. In the illustrated
embodiment, finger 74 is self-expanding. Radial expansion of finger
74 may be controlled by the intrinsic capabilities of the materials
from which it is made and/or by external factors. For example, a
slideable external sheath 75, enables control over the radial
expansion of finger 74 and thereby the degree of contact with the
arterial wall and force applied to it. FIGS. 10AA, 10BB and 10CC
show the edger together with the sheath, which may be part of the
edger device. Sheath 75 is a generally elongated hollow tube with a
lumen passing through it. A distal end of guiding catheter 75 may
include a side opening 76 and an open end 77. When distal end 72 of
edger tool 70 is positioned in the distal end of sheath 75, edger
tool 70 may be positioned as desired relative to sheath 75 to
control positioning and radial expansion of finger 74. For example,
in FIG. 10AA, finger 74 is positioned substantially away from side
opening 76 and thereby is confined by sheath 75 so that finger 74
extends substantially alongside shaft 71. FIG. 10BB shows another
position of edger tool 70 in sheath 75 where finger 74 is
substantially disposed in side opening 76 as such finger 74 may be
free to self-expand radially away from shaft 71. Typically, during
delivery, sheath 75 is positioned relative to edger 70, such that
open end 77 is proximate to finger distal tip 78, holding finger 74
essentially alongside shaft 71--"closed position." Edger 70 can
then be passed through the lesion and deployed distal to it by
sliding sheath 75 distally, bringing open end 77 over distal end
72--"open position". Sliding open end 77 back over finger 74 will
gradually bring it adjacent to shaft 71, thus controlling its angle
of opening.
[0115] As discussed above, edger tool may include one or more
fingers. FIG. 10C shows an exemplary embodiment of an edger tool 79
with 3 fingers 74a, 74b, and 74c. This embodiment operates
similarly to that described with respect to FIGS. 10AA and 10BB.
With three fingers or more, edger tool 79 is kept centered in the
arterial lumen by force of the fingers pressing against the
arterial wall all around edger 79. This is in contrast to one
finger, which may cause edger 70 to be pushed against the arterial
wall opposite finger 75. Two fingers might cause the lumen's
cross-sectional area to decrease as the artery is expanded radially
at only two points on its circumference.
[0116] The fingers in accordance with the principles of the
invention may include different configurations. For example, the
fingers may have an overall shape and cross-section with specific
profiles that enhance their ability to dissect the plaque from the
arterial wall as shown in FIGS. 10A-10F and FIGS. 10G-10K. With
references to FIGS. 10A-K, the fingers are flexible elongated
fingers as shown. The fingers are configured to scrape and peel,
but preferably are not sufficiently sharp to cut the plaque and/or
intima. Furthermore, the distal tips of the fingers point towards
the proximal end of the apparatus. Thus, these fingers are used for
removing the plaque in a backwards motion. The shape, configuration
and/or radius at the finger is not sharp as for cutting, rather it
is blunt or sufficient to find the edge of the plaque through
scraping without cutting the intima. The fingers are designed so
that radial force applied by the fingers decrease going from the
proximal to the distal end of the tip (relative to the plaque).
Thus, in one embodiment, the fingers deliver more force on the
proximal end of the finger and less force on the distal end.
Alternatively, the force may change along the fingers in a
non-linear manner, for example such that it is maximal at a certain
distance along the fingers. In one embodiment, the tips of fingers
are parallel to the shaft, thereby approximately parallel to how it
engages the artery, so that the fingers do not cut the artery. The
fingers preferably extend substantially along or in the direction
of the dissection plane. The fingers are also so configured that
they are more rigid towards the distal end and more flexible to the
proximal end. Furthermore, the edges of the fingers may be
relatively blunt, rounded, and/or curved so at to scrape along the
plaque to find the edge and/or the separation of the plaque/layer.
In one embodiment, the fingers are generally parallel to each other
along their longitudinal sections. Preferably, the distal end
results in a device that provides for a more gentle removal of the
plaque. The embodiments shown are exemplary. As discussed above,
the force differences can be achieved through structure (via e.g.
use of structural features such as struts and guidewires or
changing cross-section) or function (via e.g. use of a different
materials). The device can be used in the methods described herein,
including, being scraped along the plaque to find the edge and/or
the natural separation of the plaque.
[0117] FIGS. 10A-B illustrate a configuration of fingers 80a, where
each finger 80a is generally straight upon radial expansion. This
shape will easily "dig" under plaques on the arterial wall, as its
straight edge is pointed towards them. However, it is more prone to
puncture the arterial wall than are shapes described in FIGS.
10C-F. FIG. 10A shows an end view of a distal end of an embodiment
of an edger tool having three (3) fingers and FIG. 10B shows a side
view of the edger tool in FIG. 10A. Fingers 80a are spaced radially
equal distances apart on a main shaft as shown in FIG. 10A. Fingers
80a, when fully deployed, are at an acute angle relative to a
longitudinal axis of the shaft. Referring now to FIGS. 10C and 10D,
three fingers are positioned on the elongated shaft similar to
fingers 74 in FIGS. 10A-10B, however, fingers 80b have a different
shape, they are configured in a curved shape. Thus, the part
applying the most force on the arterial wall is not the tip but the
curvature of finger 80b. This reduces the risk of arterial injury.
Referring now to FIGS. 10E-10F, three fingers 80c, are positioned
on the elongated shaft similar to fingers 80a, 80b, in FIGS.
10A-10D, however, fingers 80c, are configured in a bent shape. This
combines the benefits of both fingers 80a and 80b: the bend
provides for a slightly sharper tool touching the arterial wall
compared with the curved 80b, thus improving its edging capability,
while at the same time preventing penetration of the tip into the
arterial wall. As discussed above, one or more fingers may be used,
and the placement and configuration of each finger may vary.
Moreover, the placement and configuration of fingers may differ
from each other on the same edger tool.
[0118] FIGS. 10G-10K illustrate alternative embodiments for
cross-sections of a hypothetical finger, embodiments of which are
described herein. The cross-section is taken transversely across a
distal end of a finger on an edger tool, with the direction of
advancement to the left. The cross-section of the finger may vary
along its length. FIGS. 10G, 10H, 10J are symmetrical. They differ
in their profiles.
[0119] The edging action includes dissecting and wedging actions.
"Dissecting" refers to the initial penetration between the layers,
and "wedging" refers to their separation. The wedging action is
mainly dependent upon the tool's wedge angle 82. Increasing this
angle for a given length will increase the forces separating the
plaque from the media. This will also increase the torque required
to rotate the tool, therefore selection of specific tool wedge
angle may be done by the physician during the procedure. FIG. 10G
shows a cross-section of fingers having a small wedge angle, which
will allow for low torque dissecting, but will be limited in the
wedging action. FIG. 10H shows a cross-section of fingers having a
larger wedge angle, which will require higher torque for the
dissecting action, but will apply larger wedging forces. FIG. 10J
depicts a finger cross-sectional shaping that is designed to reduce
the required torque for the edging action. It does so by changing
the wedge angle along the tool, so that a deeper penetration is
achieved before the larger angled part of the finger induces the
separating forces. FIGS. 10I and 10K, both having an asymmetrical
cross-sectional shaping, are examples of possible design solutions
that utilize finger shaping to exert forces on the fingers,
directing them towards the separation plane.
[0120] The retrograde edger tool is rotated around its axis and
simultaneously retracted so that the finger edges perform a spiral
movement on the arterial wall. This movement gradually separates
the plaque edge from the arterial wall (FIG. 11).
[0121] More particularly, FIG. 11 shows retrograde edger tool 70 in
action. Artery with media 10 is seen in longitudinal section,
plaque 12 is shown in 3D for demonstration purposes. Edger 70 has
been deployed by pushing sheath 75 distally, after being passed
through guiding catheter 30 and plaque 12. Edger 70 is in the fully
open position, and is being rotated and pulled back thereby
scraping, pealing and lifting the edge of the plaque. This is done,
preferably, without cutting or damaging the artery.
[0122] As an adjunct to the above, a jet of saline or other
biocompatible fluid may be used to assist in the dissection, shown,
for example, in FIGS. 12-14.
[0123] FIG. 12 shows guiding catheter 30 in artery with media 10
seen in longitudinal section, plaque 12 in three-dimensional. Jet
edger tool 100 deployed with sheath 110 positioned such that
fingers 101 are at fully open position. Open end 111 has nozzle 112
emitting jet 115. Fingers 101 have nozzles 102 emitting jet 105.
Suction tube 120 removes excess fluids. Jets 115 and 105 aid in
edging the plaque while edger 100 is rotated and pulled
proximally.
[0124] Suction of excess fluid out of the blood vessel to prevent
an undesirable increase in pressure may be performed through
suction tube 120 as shown in FIG. 12. Suction may be used in
combination with any of the embodiments described herein. Suction
may be controlled either by keeping the net volume of injected
fluid below a certain threshold, or by keeping the pressure in the
vessel below a certain threshold.
[0125] Such a jet may be directed towards the arterial wall through
the above-mentioned fingers as shown in FIG. 13A.
[0126] The jet may be constant or intermittent, fixed or pulsatile.
The jet may form a cross-sectional shape that is circular,
elliptical or any other shape as shown for example in FIGS. 13A-C.
FIG. 13A shows cross-section through artery and finger, depicting
media 10 and plaque 12 being separated by finger 101, while nozzle
102 emits jet 105. FIG. 13B shows circular nozzle 116a emitting jet
105 having circular cross-section 117a. FIG. 13C shows elliptical
nozzle 116b emitting jet 105 having elliptical cross-section 117b.
A jet with an elliptical cross-section may be more effective in
dissection than a jet with a circular cross-section when directed
at the arterial wall with its longitudinal axis parallel to the
arterial longitudinal axis.
[0127] Such a saline jet can be used instead of the fingers as
shown in FIG. 14. FIG. 14 shows artery with media 10 seen in
longitudinal section, plaque 12 in three dimensions. Guiding
catheter 30 has balloon 31 inflated. Balloon 140 is placed and
inflated distally. Jet edger tool 131 has nozzle 132 emitting jet
135. Suction tube 120 removes excess fluids. Jet 135 edges and
dissects the plaque while edger 100 is rotated. In this embodiment,
both edging and dissection may be performed by jet only, while the
treated area is isolated between the two balloons. Alternatively, a
similar jet edger tool may be used in anterograde fashion, when
passage through the lesion is not possible, for example on a lower
limb. Distal isolation may be achieved by external compression of
the limb. Mixing contrast material with the jet fluid can enable
angiographic visualization of the progression of subintimal
dissection.
[0128] The tools described herein may be used under direct vision
by endoscopy or other visualization method, as can optionally be
done with all the edger and dissection tools described herein.
[0129] An alternative embodiment of the edger tool pertains to the
structure of the fingers. As shown in FIG. 15, the fingers can be
made of looped metal wires, or a laser cut metal tube or sheet.
FIG. 15 shows wire 150 bent at point 151, with both ends returning
to the base 152. Alternatively, the edger fingers can be made of
metal tubes through which are passed metal wires. FIG. 16A shows
such metal tube 160, compressed at its distal tip 161, and metal
wire 162 extending therethrough. 16B is the same finger with wire
loop slightly more distally extended. This structure can enable
combining both edger and dissector into one tool, such that after
edging is performed, the wire loops 162 can be extended into the
SIS from the edges 161 of the fingers 160.
[0130] An alternative approach to entering the SIS is based on an
intentional cut of the intima, proximal to the lesion. This can be
done using a specialized tool with a blade of predetermined depth.
This is shown in FIG. 17: catheter 30 with balloon 31 in artery
with media 10 and normal intima 11 proximal to lesion 12. Proximal
intima cutting tool 170 includes a metal strip having elongated
shaft 171, which curves into a radial part 172 oriented
circumferentially from which a distally inclined blade 173 of
height 174 protrudes radially. Sheath 175, which covers the tool
before deployment, is retracted to enable its expansion and contact
with intima 11. Rotation of proximal intimal cutter 170 several
times cuts a thin incision through the intima. The tool 170 is
covered by sheath 175 and removed. This can later be followed by
deployment of radially expansive dissector tool, which when
expanded radially and advanced distally, find its way into the
incision, and enters the SIS or an adjacent dissection plane within
the media.
[0131] Another aspect of the invention is a dissector tool.
Dissection and advancement of the dissector may be aided by
vibration that may be applied to the tool, and/or saline jet
dissection as previously described.
[0132] An example of a tool intended for separating the rest of the
plaque from the arterial wall is shown in FIGS. 18A and 18B. This
embodiment includes a cylindrical bag, which is rolled up or folded
into a ring. The ring is mounted on an elongated member. The bag
has longitudinal inflatable strips in it that can be inflated
through the external edge of the elongated member. The tool is
placed in the artery via the guiding catheter. The ring is inserted
between the plaque and media of the artery, preferably over the
edger tool. Inflation of the longitudinal strips causes the bag to
open and lengthen while dissecting between the plaque and media.
This and additional similar embodiments are depicted in FIG. 18c in
side view.
[0133] More particularly, in FIGS. 18A-B, dissection tool is shown
generally at 180. FIG. 18A is a three-dimensional view of the
device while FIG. 18B is a longitudinal section through the artery
and device. FIG. 18A shows inflatable dissection tool 180 which has
longitudinal inflatable strips 183 configured in a funnel shape
when inflated. The ends of the strips face inwards. The inflatable
dissection tool further includes longitudinal bag 181 which is
surrounded by the longitudinal inflatable strips 183 and folded bag
182 which is towards the distal end of the tool 189. The folded bag
182 may be integral with longitudinal bag 181. FIG. 18B shows media
10, plaque 12, already slightly separated at edge by edger tool.
With reference FIG. 18B, Inflatable dissection tool 180 is depicted
with its longitudinal bag 181 in the lumen and the folded bag part
182 in the SIS. Once the longitudinal strips are inflated, the
device unfolds while dissecting further between the layers.
[0134] FIGS. 18C-F show alternate embodiments of a distal end of
dissection tools as described above with reference to FIGS. 18A-B.
FIG. 18C shows dissection tool 180 described above. FIG. 18D shows
another aspect of a dissection tool 180a. This device is identical
to 180 except the direction of folds is inwards instead of
outwards. Compared to 180a, tool 180 has the advantage of pushing
the media outwards, whereas tool 180a pushes the intima inwards
towards the plaque, which causes more resistance. FIG. 18E shows
another aspect of a dissection tool 180b. This tool is folded as a
harmonica fashion instead of being rolled. FIG. 18F shows another
aspect of a dissection tool 180c. Both 180b and 180c encounter less
resistance to unfolding than do 180 and 180a, however, the method
of making the folds is simpler in the rolled up devices 180 and
180a. Importantly, devices 180 and 180a can be made of braided
stents instead of a polymer bag. Instead of using inflation, they
can be unfolded for example by pushing the folded ring forward at
several points with wires extending proximally through the guiding
catheter.
[0135] With regard to the distal intimal cutting tool, there are
several additional embodiments. The distal intimal cutting tool 60
previously described may be inserted through a specialized groove
located in the wall of the guiding catheter (FIG. 19A-B). 19A shows
cross-section of multi-lumen guiding catheter 190 with catheter
main lumen 191 and cutting tool groove 192. FIG. 19B shows a
longitudinal section of the artery with cutting tool 60 extending
from groove, inserted between media 10 and dissector tool 50, and
cutting intima 11 at plaque edge. Alternatively, the cutting tool
may be inserted through lumen 191 over or instead of dissector.
[0136] Another approach to cutting the intima at the edge of the
lesion is based on the shape memory properties of the nitinol wires
including dissector 200, shown in FIG. 20A-D. FIG. 20A shows
dissector 200 having one or more dissector tip 201 at the distal
end and loopwires 202, which is identical to dissector 50, apart
from having been thermally treated to assume a thermally dependent
conformation change. At normal body temperature, the dissector has
a slight outward angulation of tip 201. FIG. 20B shows dissector
after being heated/cooled--the angulation changes towards the
interior of the lumen. FIGS. 20C-D show same in arterial
longitudinal section. This change in angulation inwards can cause
re-entry of the loops into the lumen. Alternatively, a needle may
be extended from the edge of one of the loops, and after its entry
into the lumen, a guide wire can be passed through it.
[0137] In some embodiments of the cutting tool, there are multiple
tools on the dissector, each slideably attached to a loop's
centerline. This allows for cutting around the whole intima with
partial rotation of the dissector. After cutting and blade
retraction, the cutting tools can be pushed forward such that they
bend towards the center of the lumen and form a wall that assists
in holding the plaque as it is pulled back and removed.
[0138] Medial aspect: This approach is based on threading a
guidewire through the subintimal space from one end of the plaque
to the other, then using a tool, which expands along this space,
thus peeling the plaque from the arterial wall. This is intended to
peel the plaque, which includes the intima, while leaving the media
and adventitia intact. Sometimes, especially if the plaque involves
the media, some medial layers might be peeled as well. However,
this should not pose a major problem, as it often occurs during
surgical endarterectomy, and does not cause any complications.
[0139] An embodiment of this approach is shown in FIGS. 21-23. A
guidewire is introduced into the subintimal space and advanced
along the lesion and beyond its far end, then back into the lumen.
A separator device such as that shown in FIG. 23 (in its deployed
state) is introduced over the wire (in its folded, non-deployed
state). This tool includes a hollow cylinder with a longitudinal
slit, folded onto an elongated member. When deployed, it assumes
its cylindrical shape with an overlap of both ends over the
slit.
[0140] This can be achieved for example by an inflatable balloon
constructed of multiple longitudinal chambers having a trapezoid
cross-section and connected to each other side by side. As the
balloon is inflated, it dissects around the plaque, separating it
from the arterial wall and encompassing the dissected plaque.
[0141] More particularly, with reference to FIG. 21A, a
three-dimensional view of artery with deployed device 210 is
depicted. Guidewire 211 inside device catheter 212 is seen
intraluminally, then passes via intima 11 into subintimal space
("SIS") 214, and is again seen intraluminally 213 distal to lesion.
FIG. 21B is a cross-section of device 210, folded balloon 215,
catheter 212, and bilateral longitudinal radiopaque markers. The
device may optionally have one or more longitudinal markers
216.
[0142] With reference to FIGS. 22A-F, the stages of this procedure
are depicted. FIGS. 22A and 22B are longitudinal and transverse
views of non-deployed device 210 passed over guidewire 211 in SIS,
traversing lesion 12. FIGS. 22C and 22D are longitudinal and
transverse views of device 210 partially deployed. FIGS. 22E and
22F are longitudinal and transverse views of device 210 at full
deployment, encompassing lesion 12. FIG. 23 is a three-dimensional
view of the deployed device 210 with catheter 212.
[0143] Prior to deployment, angiography can be used to ascertain
the device is at the optimal orientation for deployment. Radiopaque
markers 216 must be demonstrated parallel to each other at the
medial border of the plaque. During deployment, the markers may be
seen moving across the lumen to encompass the lesion.
[0144] After the device is fully deployed, a distal intimal cutting
tool 60 can be used to free the connecting intima. Such tool 60 may
either be integral with the dissector 210, or a separate tool used
in combination with 210.
[0145] Alternatively, a similar device 220 may be formed of
transverse longitudinal strips, each having a slight curvature,
such that when inflated the device assumes a flat shape, with only
slight radius of curvature. This increases the tendency of the
dissector to inflate within the SIS without encroaching on the
arterial lumen. FIG. 24 is a 3D view of the flat device 220 with
catheter 222.
[0146] A different embodiment shown in FIGS. 25A-C is based on a
nitinol device composed of multiple arched wires stemming off both
sides of a central longitudinal spine. A sheath covers those "ribs"
holding them flatly adjacent to the spine. When the sheath is
removed, the ribs dissect around the plaque and form a cage
encircling it.
[0147] More particularly, FIG. 25A shows device 230 at 3D. FIG. 25B
shows a side view of device 230 shown in FIG. 25A. FIG. 25C shows
and end view of device 230 in FIG. 25A. Ribs 232 extend laterally
from spine 231
[0148] The above described devices 210, 220 and 230, which dissect
and contain the plaque, may have a predetermined shape such that
their distal end is closed. This allows for containment of the
dissected plaque inside such structure, which prevents debris from
embolizing. Alternatively, the distal end only or both ends may be
closed for example by a wire traversing that end in a
"purse-string," which wire can be tightened by pulling on such
wire.
[0149] Inflating a balloon or deploying a nitinol web at the open
end are additional ways for closing the aperture.
[0150] Removal of the freed plaque from the body can be achieved in
several ways. If the volume of plaque is not very large, it may be
possible to remove the plaque as is within the containment
structure through the introducing sheath and outside of the artery.
However, in some cases the plaque will be too large for such
removal, and will need to be ground into small pieces.
[0151] Grinding the plaque can be done by a grinder mounted on a
catheter, with a suction catheter as part of the same tool or used
in conjunction with it. If the proximal end of the containment
structure holding the plaque has been closed, it will need to be
penetrated by such catheter to contact the plaque.
[0152] A useful addition to the above is a modification for
preventing clogging of the grinder device.
[0153] In cases where the freed plaque was not contained in a bag
or chamber, balloons should have been inflated on both sides of the
work area to isolate it. Grinding and aspiration of the plaque can
take place in this isolated area, followed by rinsing of the space
with saline to ensure removal of all debris.
[0154] In some embodiments, after plaque removal, the treatment
area is isolated between balloons and flushed with isotonic fluid
in rapidly changing directions and pressure, in order to wash away
any residual loosely adherent plaque, intima, or medial tissue.
Alternatively or in addition, a fogarty catheter may be passed over
the treated in a gentle manner. Other methods of ensuring removal
of residuals include angiography, IVUS, or visual inspection.
[0155] Following completion of the percutaneous atherectomy using
the methods and devices described above, the next stage of
treatment begins. FIG. 28 shows device 400 situated across area 500
where lesion was removed. Device 400 is a multilumen catheter
intended for isolation of the treated area and delivery of medial
layer therapy. Catheter 400 has lumen 401 for blood flow across
isolated area 501. Lumen 402 inflates proximal balloon 412, lumen
403 inflates distal balloon 413. Lumen 404 serves for inflow of
therapy and lumen 405 for outflow.
[0156] In use, proximal balloon 412 and distal balloon 413 are
inflated. Blood passes freely through the blood flow lumen.
Treatment may be delivered according to the specific protocol--e.g.
perfusion with saline or blood, and instillation of the treating
agent--usually endothelial progenitor cells. The treatment
continues for the required duration. The area is flushed with
saline and refilled with the patient's blood, the balloons are
deflated, and catheter 400 removed.
[0157] Another aspect of the current invention includes devices for
insertion of guidewires into the SIS. Such a device intended for
non-CTO lesions is shown in FIGS. 26A-B and includes a multilumen
catheter, proximal and distal balloons, a suction lumen, and a
catheter for passing a guidewire extending across the periphery of
the proximal balloon. FIG. 26A is a longitudinal section through
artery and device 250 showing device catheter 251, proximal balloon
lumen 252, distal balloon lumen 253, suction lumen 254, guidewire
catheter 255, guidewire 256, proximal balloon 257, distal balloon
258. FIG. 26B is a front view of same device. In use, device 250 is
brought proximate to the plaque edge such that distal balloon 253
is within lesion. Proximal balloon 257 is inflated, followed by
distal balloon inflation. Inflation of the balloons produces a
force pushing the plaque distally and normal artery proximally, as
well as an outward force on the arterial wall proximal to the
lesion. These forces apply tension on transition zone 259 between
"normal" intima 10 proximal to the lesion and plaque 12. The
pushing force between the plaque and proximal artery may be
increased by making distal balloon 253 moveable forward relative to
guidewire catheter 255. The guidewire catheter is compressed
against the arterial wall by the proximal balloon, and assumes an
angle up to approximately 5 degrees outwards of the longitudinal
arterial axis, leading the guidewire towards transition zone 259.
Optionally, suction may be applied to the suction lumen, reducing
the pressure in the area between the balloons and pulling the
plaque away from the arterial wall towards the center of the lumen.
The combination of increased tension in transition zone 259, exact
direction of the guidewire towards transition zone 259, and pulling
of plaque 12 away from arterial wall 10, facilitates entry of
guidewire 256 through transition zone 259 into SIS.
[0158] In another embodiment, a similar device 270 is provided for
insertion of multiple guidewire around the lesion. FIG. 26C shows
device 270 having device catheter 271 in front view with four
guidewire catheters 275a-d leading four guidewires 276a-d into the
SIS in the same manner described for device 250.
[0159] For CTO lesion or other lesions where a balloon cannot be
inflated to within the lesion, a similar device is provided which
uses an umbrella-like contraption instead of the distal balloon.
FIG. 27A illustrates this device in an artery's longitudinal
section. With reference to FIG. 27A, device catheter 291 is shown
having proximal balloon lumen 292 and umbrella and suction lumen
293. The umbrella 294 is shown passing through the lumen of the
device catheter 291. Guidewire catheter 295 containing guidewire
296 also passes the lumen of the device catheter 291. Umbrella 294
has umbrella distal end 298 FIG. 27B shows a front view of the
catheter device and 27C a front view of the umbrella device. In
use, device 290 is brought proximate to the plaque edge. Proximal
balloon 297 is inflated, followed by deployment of umbrella 294.
Inflation of the proximal balloon and pushing umbrella 294 forward
produces a force pushing the plaque distally and normal artery
proximally, as well as an outward force on the arterial wall
proximal to the lesion. These forces apply tension on transition
zone 299 between "normal" intima 10 proximal to the lesion and
plaque 12. The guidewire catheter is compressed against the
arterial wall by the proximal balloon, and assumes an angle up to
approximately 5 degrees outwards of the longitudinal arterial axis,
leading the guidewire towards transition zone 299. Optionally,
suction may be applied to the suction lumen, reducing the pressure
in the area between the proximal balloon 297 and plaque and pulling
the plaque away from the arterial wall towards the center of the
lumen. The combination of increased tension in transition zone 299,
exact direction of the guidewire towards transition zone 299, and
pulling of plaque 12 away from arterial wall 10, facilitates entry
of guidewire 296 through transition zone 299 into SIS.
[0160] In yet another embodiment, a device based on the edger tool
20 can be used to deliver guidewires to the SIS. One or more
guidewire catheters are attached to fingers 21 of edger, such that
when edger fingers enter SIS or are proximate to it, pushing
forward the guidewires will result in their entry to the SIS.
Multiple such guidewires in the SIS can be used as a dissection
means for short plaques or as a lead for insertion of a dissector
too.
[0161] Another embodiment of the invention is described in FIG. 29.
This embodiment involves use of an anvil-like tool, which is placed
distal to the lesion in order to assist with the distal intimal
cutting stage. More particularly, FIG. 29 shows a longitudinal
section of artery with media 10, plaque 12, guiding catheter 30
anchored by balloon 31. Anvil 600 is a cylindrical tool including
body 601 continuous with elongated shaft 602, and several wings 603
each with distal tip 604 and distal edge 605. Wings 603 are formed
such that when deployed, wings 603 flare outwards and distal edges
605 form an essentially continuous circumferential line around the
inside of the lumen of the artery. Wings 605 may optionally be
covered by web 606. Also provided is cap 610 including body 611 and
elongated shaft 612. Body 611 is cylindrical and continuous with
elongated shaft 612. Cap 610 can be pulled to cover Anvil 600,
which folding wings 603 towards the elongated shaft 602. Elongated
shaft 612 is threaded through elongated shaft 602, and both parts
are passed through the guiding catheter 30, optionally over
guidewire 620.
[0162] In use, anvil 600 is passed through guiding catheter 30 and
inside lesion 12, and deployed distal to it by pushing cap 610
distally, such that anvil distal edges 605 press against the
arterial wall and cause it to bulge outwards slightly. Web 606 of
anvil 600 may then act as an emboli protection device. Edging or
proximal intimal cutting is then performed in a manner similar to
that described for previous embodiments, and dissection tool 50 is
passed in guiding catheter 30 over elongated shaft 602 and through
SIS until it reaches the distal plaque edge. At this point, pushing
dissection tool 50 forward will cut intima between anvil distal
edges 605 and loop centerlines 53. Cap 610 can then be pulled back
to slightly close anvil 600 and dissector 50 to enable removal of
all instruments together.
[0163] Using the anvil tool enables anchoring of the intima to the
media during distal cutting, thus preventing or reducing the risk
of creation of an intimal flap.
[0164] It is clear to anyone familiar with the art that the above
described devices and methods can be used in any other organ in the
body that has an elongated lumen such as the gastrointestinal
tract, pulmonary system, urinary system etc.
[0165] Potential alternative applications of the above include but
are not limited to biopsies, removal of tumors or pathological
tissues.
[0166] Although the foregoing description is directed to the
preferred embodiments of the invention, it is noted that other
variations and modifications will be apparent to those skilled in
the art, and may be made departing from the spirit or scope of the
invention. Moreover, features described in connection with one
embodiment of the invention may be used in conjunction with other
embodiments, even if not explicitly stated above. The present
invention may be embodied in other specific forms without departing
from its spirit or essential characteristics. The described
embodiments are to be considered in all respects only as
illustrative and not restrictive.
* * * * *