FIELD OF THE INVENTION
[0001] The present invention, in some embodiments thereof, relates to devices and kits for
preventing or reducing non-target microparticles deposition and embolization, in conjunction
with delivering microparticles (e.g., an embolization material) via a blood vessel
to a target bodily part. Some embodiments of the invention relate to devices for entrapping
infiltrated microparticles within the heart right atrium. Document
US2003/130680 discloses a releasable and retrievable vascular filter system, according to the preamble
of claim 1.
BACKGROUND OF THE INVENTION
[0002] The purpose of embolization therapy is to prevent blood flow to an area of the body.
Embolization therapy can effectively shrink a tumor or block an aneurysm, and is commonly
carried using an endovascular catheter. Access to the organ in question is acquired
by means of a guidewire and catheter(s). The position of the correct artery or vein
supplying the pathology in question can be located by digital subtraction angiography
(DSA), producing images are then used as an accessing map to the correct vessel. An
artificial embolus can be formed when using coils, particles, foam, plug, microspheres
or beads, as an embolization material.
[0003] Transarterial embolization therapy, tumor embolization, or transcatheter arterial
embolization (TAE), involves administration of embolization material (which may include
chemotherapeutics or/and radiotherapeutics) directly to a tumor typically associated
with a target bodily part, such as an organ (for example, the liver), via a catheter.
These techniques are usually performed using a microcatheter which targets the tumor,
while attempting to avoid dispersion of embolization material to healthy organs.
[0004] One of the problems associated with embolization therapy is commonly known as "non-target
embolization", where the embolic material travels along small blood vessels, other
than those which directly feed the target tumor or region. Non-target embolization
is partly caused by shunts that are commonly formed in cancers at advanced stages
and that bypass existing capillary bed to integrate the blood circulation.
[0005] For example, embolization liver therapy is a procedure associated with the insertion
of a catheter into the hepatic artery and injection of embolization material. The
embolization material may include chemotherapeutics or radiotherapeutics which may
infiltrate also to sensitive tissues and organs, such as to the lungs, through arteriovenous
shunts. This can damage healthy tissues in these areas, often resulting in serious
complications. Specific serious complications and toxicities are associated with radioembolization.
This technique may be associated with non-target deposition of embolic material comprising
yttrium-90 (
90Y) in tissues such as healthy liver tissue, stomach, bowel, and lungs. Such non-target
deposition may, for example, cause a liver disease when deposition of the embolic
material is within healthy or functional liver, ulceration when deposition of the
embolic material is within the stomach or bowel, and radiation pneumonitis (RP) when
deposition of the embolic material is within the lungs.
[0006] Another problem associated with embolization therapy is reflux or backflow of the
embolic material during the embolization procedure. Reflux is a potential complication
which can result in occlusion of distal vascular beds. The conditions under which
reflux was demonstrated include (1) low flow states, (2) overvigorous flushing, (3)
selective contrast injections, and (4) placement of embolic material too proximally.
[0007] In view of the preceding, and other limitations associated with current embolization
techniques, there is a need for developing and practicing improved or/and new techniques
for delivering embolization material into small blood vessels located in close proximity
to a target body part, while diminishing or preventing non-target embolic material
deposition and embolization.
SUMMARY OF THE INVENTION
[0008] The present invention, in some embodiments thereof, relates to devices and kits for
preventing or reducing non-target microparticles deposition and embolization, in conjunction
with delivering microparticles (e.g., an embolization material) via a blood vessel
to a target bodily part. Some embodiments of the invention relate to devices for entrapping
infiltrated microparticles within the heart right atrium, as disclosed in the appended
set of claims.
[0009] In some embodiments, the present invention provides kits and devices for reducing
or preventing non-target delivery of an embolic material by capturing embolic material
infiltrated to the blood circulation from a body organ outflow. In further embodiments,
the invention relates to embolic material entrapping devices configured for positioning
within a blood vessel, downstream to a target body organ, or within a non-target body
organ, for capturing embolic material infiltrated to a body organ outflow. In yet
further embodiments, the present invention may provide a solution to the problem of
non-target embolization that may be associated, for example, with shunting (e.g.,
pulmonary shunting) phenomena or/and reflux phenomena.
[0010] By providing means to entrap embolic material within a non-target body organ or a
blood vessel, some embodiments of the present invention may provide for a safe embolization
therapy and allow utilizing this technique also within a patient population that has
been otherwise prohibited from embolization therapy or that has been limited to a
reduced therapeutic dosage of embolic material.
[0011] According to an aspect of some embodiments of the present invention there is provided
an entrapping device for preventing or reducing non-target deposition of embolic material
following embolization therapy in a blood vessel feeding a target organ in a subject,
the entrapping device comprising: a filter; and a filter collapsing mechanism, sized
for being positioned in a catheter lumen of a filter delivering catheter, and having
a proximal end actuatable from outside of the subject; wherein the filter is configured
for positioning within a heart right atrium via an inlet opening of the right atrium,
and, for self-expanding and covering the right atrium inlet opening from within the
right atrium, and is sized and configured such that, when expanded, the filter collects
the embolic material delivered to the target organ and infiltrated into an outflow
vessel of the target organ draining to the right atrium; and wherein the filter collapsing
mechanism is configured for collapsing, and for being manipulated into forming a pocket
in the filter, so as to entrap the collected embolic material in the pocket, and for
drawing the filter with the collected embolic material in the pocket, into the catheter
lumen of the filter delivering catheter.
[0012] According to some embodiments of the invention, the filter collapsing mechanism includes:
an elongated tubular body connectable with a distal end to the filter; and a drawstring
extendable from an opened proximal perimeter of the filter to outside of the subject,
wherein the drawstring is passable within the elongated tubular body; wherein the
filter collapsing mechanism is configured for the collapsing and the being manipulated
by pulling the drawstring away from the filter against the elongated tubular body.
[0013] According to some embodiments which are not part of the invention, the filter has
a cap-shape structure sized and configured to seal the inlet opening of the heart
right atrium.
[0014] According to the invention, the entrapping device further comprises a hollow circumferential
sleeve connected about a proximally opened perimeter of the filter and configured
for housing the drawstring at the proximally opened perimeter of the filter.
[0015] According to some embodiments of the invention, the filter delivering catheter is
configured for housing the entrapping device in a collapsed configuration. According
to some embodiments of the invention, the filter comprises a fine mesh having strands
with a thickness of about 200 micrometers or less, or optionally particularly about
100 micrometers or less. According to some embodiments of the invention, the filter
comprises pores configured to block passage therethrough of the embolic material and
to allow passage therethrough of incoming blood flow.
[0016] According to some embodiments of the invention, the embolic material has a diameter
equal to or greater than a predetermined size. According to some embodiments of the
invention, the predetermined size is within a range of between about 20 micrometers
and about 60 micrometers.
[0017] According to some embodiments of the invention, the entrapping device is configured
for collecting the embolic material in a form of: beads, foam, or gel. According to
some embodiments of the invention, the beads are loaded with a radioactive agent or
a chemotherapeutic agent.
[0018] According to an aspect of some aspects which are not part of the invention there
is provided a method of applying multi-layered protection from non-target embolization
or/and non-target deposition of microparticles in a subject, the method comprising:
positioning an entrapping device in a first anatomical location downstream to a target
organ, the entrapping device is configured to filter the microparticles from blood
flow and to entrap the microparticles; placing a distal outlet of a microcatheter
in a second anatomical location upstream to the target organ; delivering an infusion
suspension including the microparticles via the distal outlet in the second anatomical
location upstream to, and towards, the target organ, while allowing a continuous blood
flow downstream towards and away from the target organ, by applying a flow disturbance
mechanism in the second anatomical location, proximally to the microcatheter distal
outlet, thereby creating a local disturbance in blood flow so as to suppress a retrograded
flow of the microparticles flowable upstream to the target organ; and removing the
entrapping device from the subject following a chosen time, after ceasing of the delivering,
sufficient for allowing the entrapping device to entrap infiltrating microparticles
infiltratable upstream through the flow disturbance mechanism or/and downstream to
the target organ.
[0019] According to some embodiments of the invention, the microparticles include, or are
included in, embolic material, and are configured for forming emboli.
[0020] According to some embodiments of the invention, the chosen time is additionally sufficient
for allowing the microparticles to form an embolus in a target blood vessel feeding
the target organ, the embolus is sized for occluding the target blood vessel.
[0021] According to some aspects of the disclosure, which are not part of the invention,
the target organ is a liver in the subject. According to some aspects, which are not
part of the invention the first anatomical location is a non-target vessel connecting
the target organ to a non-target organ and providing blood flow communication therebetween.
According to some aspects, which are not part of the invention the non-target vessel
is an abnormally formed shunt connecting the target organ to a vein carrying deoxygenated
blood towards the subject's heart. According to some aspects, which are not part of
the invention the non-target vessel is an inner portion of the heart, such as the
right atrium, in the subject.
[0022] According to some embodiments of the invention, the second anatomical location is
a target blood vessel feeding the target organ.
[0023] According to some aspects, which are not part of the invention, in the method, placing
the distal outlet is performed concomitantly with, following, or before, positioning
the entrapping device.
[0024] According to some aspects, which are not part of the invention, in the method, positioning
an entrapping device, comprises: providing a filter delivering catheter, the filter
delivering catheter comprises a proximal end, a distal end, and a lumen extending
therebetween the ends, and is configured for housing the entrapping device in a collapsed
configuration; introducing the filter delivering catheter into the first anatomic
location; and deploying the entrapping device to thereby facilitate the positioning.
[0025] According to some embodiments of the invention, the entrapping device comprises a
filter and a filter collapsing mechanism, the filter collapsing mechanism is sized
for being positioned in a catheter lumen of the filter delivering catheter, and has
a proximal end actuatable from outside of the subject, and wherein the deploying the
entrapping device comprises retracting the filter delivering catheter or/and removing
the filter from the catheter lumen using the filter collapsing mechanism.
[0026] According to some aspects, which are not part of the invention, the method further
comprises, prior to introducing the filter delivering catheter, inserting a guidewire
for facilitating access and delivery of the filter delivering catheter within a blood
vessel, downstream to the target organ or within a non-target organ.
[0027] According to some embodiments of the invention, the filter collapsing mechanism includes
an elongated tubular body connected with a distal end to the filter, and a drawstring
extending from an opened perimeter of the filter and continuously threaded within
the elongated tubular body; wherein deploying the entrapping device comprises pushing
the elongated tubular body distally, to thereby deploy in an outwardly direction the
entrapping device, and wherein removing the entrapping device comprises re-collapsing
the entrapping device with entrapped microparticles inwardly within the filter delivering
catheter by proximally pulling the drawstring.
[0028] According to some embodiments of the invention, the microcatheter comprises: a tubular
wall having a proximal wall end, a distal wall end, and a lumen extending between
the wall ends, the lumen is opened to the distal outlet at the distal wall end and
to a plurality of side openings distributed around or/and along a section of the tubular
wall proximally to the distal outlet; the microcatheter is configured to deliver an
infusion suspension including the microparticles suspended in an infusion fluid, via
the lumen to the distal outlet; wherein the distal outlet is shaped or/and sized to
allow passage therethrough of the infusion suspension, and each of the side openings
is shaped or/and sized to allow passage therethrough of the infusion fluid without
the microparticles and to block passage therethrough of the microparticles.
[0029] According to some embodiments of the invention, at least one of the side openings
comprises a slit with a gap having a maximal cross sectional dimension less than a
minimal diameter of the microparticles. According to some embodiments of the invention,
at least one of the side openings comprises a pore having a maximal cross sectional
dimension less than a minimal diameter of the microparticles.
[0030] According to some aspects, which are not part of the invention, in the method, positioning
the entrapping device comprises deploying the entrapping device to thereby cover a
wall of the first anatomical location, downstream to the target organ. According to
some embodiments of the invention, the first anatomical location is a hepatic vein
or a portion of the inferior vena cava, above the hepatic vein. According to some
aspects, which are not part of the invention, the target blood vessel is a small blood
vessel directly feeding cancerous tissue of the target organ.
[0031] According to an aspect of some aspects, which are not part of the invention, there
is provided a method for performing local embolization in a blood vessel feeding a
target organ in a subject, the method comprising: positioning an entrapping device
within a heart right atrium via an inlet opening of the right atrium, the entrapping
device is configured to filter embolic material from blood flow, and to entrap the
embolic material; deploying the entrapping device to thereby cover the inlet opening
of the right atrium from within the right atrium; placing a distal outlet of a microcatheter
in the blood vessel feeding the target organ; delivering the embolic material via
the distal outlet in the blood vessel towards the target organ; and removing the entrapping
device from the subject following a chosen time after ceasing of the delivering, sufficient
for allowing the entrapping device to entrap the embolic material infiltratable in
the heart right atrium.
[0032] According to some aspects, which are not part of the invention, in the method, placing
the distal outlet of the microcatheter in the blood vessel is performed concomitantly
with, following, or before positioning the entrapping device in the blood vessel.
[0033] According to some aspects, which are not part of the invention, in the method, positioning
the entrapping device, comprises: providing a catheter having a proximal end, a distal
end, and a lumen extending therebetween the ends, the catheter is configured for housing
the entrapping device in a collapsed configuration; and inserting the catheter into
the heart right atrium.
[0034] According to some embodiments of the invention, the entrapping devices comprises
a filter and an elongated tubular body connected with a distal end to the filter,
and wherein deploying the entrapping device comprises retracting the catheter proximally
or pushing the elongated tubular body distally, to thereby deploy in an outwardly
direction the entrapping device.
[0035] According to some aspects, which are not part of the invention, the method further
comprises inserting, prior to introducing the catheter, a guidewire for facilitating
access and delivery of the catheter within the blood vessel, downstream to the target
organ or within a non-target organ.
[0036] According to some aspects, which are not part of the invention, the entrapping device
further comprises a drawstring extending from an opened perimeter of the filter and
continuously threaded within the tubular body, and wherein removing the entrapping
device comprises re-collapsing the entrapping device with the entrapped embolic material
inwardly within the catheter by proximally pulling the drawstring.
[0037] According to some embodiments of the invention, the microcatheter comprises: a tubular
wall having a proximal wall end, a distal wall end, and a lumen extending between
the wall ends, the lumen is opened to a distal outlet at the distal wall end and to
a plurality of side openings distributed around or/and along a section of the tubular
wall proximally to the distal outlet; the microcatheter is configured to deliver an
infusion suspension of the embolic material in an infusion fluid, via the lumen to
the distal outlet; wherein the distal outlet is shaped or/and sized to allow passage
therethrough of the infusion suspension, and each of the side openings is shaped or/and
sized to allow passage therethrough of the infusion fluid without the embolic material
and to block passage therethrough of the embolic material.
[0038] According to some embodiments of the invention, at least one of the side openings
comprises a slit with a gap having a maximal cross sectional dimension less than a
minimal diameter of the embolic material. According to some embodiments of the invention,
at least one of the side openings comprises a pore having a maximal cross sectional
dimension less than a minimal diameter of the embolic material.
[0039] According to an aspect of some embodiments of the present invention there is provided
a kit for preventing non-target deposition of embolic material, the kit comprising
an entrapping device configured for capturing the embolic material within a blood
vessel, downstream to a target organ or a non-target organ, and a microcatheter configured
for delivering the embolic material into the blood vessel feeding a bodily organ.
[0040] According to some embodiments of the invention, in the kit, the entrapping device
comprises: a collapsible filter, an elongated tubular body connected with a distal
end to the filter and actuatable with a proximal end thereof from outside the subject
body, and a drawstring extended from an opened proximal perimeter of the filter and
continuously threaded within an inner lumen of the elongated tubular body; the filter
is configured for positioning within a heart right atrium via an inlet opening of
the right atrium, and for self-expanding and covering the right atrium inlet opening
from within the right atrium, and is sized and configured for collecting the embolic
material delivered to the target organ and infiltrated into an outflow vessel of the
target organ draining to the right atrium; the drawstring is configured for re-collapsing
the filter into forming a pocket, by proximally pulling the drawstring, so as to entrap
the collected embolic material in the pocket; and the elongated tubular body is configured
for drawing the filter, with the embolic material in the pocket, into a lumen of a
catheter.
[0041] According to some aspects, which are not part of the invention, in the kit, the filter
has a cap-shape structure configured to seal the inlet opening of the heart right
atrium.
[0042] According to the invention, the kit further comprises a hollow circumferential sleeve
connected about a proximally opened perimeter of the filter and configured for housing
the drawstring at the proximally opened perimeter of the filter. According to some
embodiments of the invention, the catheter is configured for housing the entrapping
device in a collapsed configuration. According to some embodiments of the invention,
the filter comprises a fine mesh having strands with a thickness of no more than 200
micrometers. According to some embodiments of the invention, the filter comprises
pores configured to block passage therethrough of an embolic material and to allow
passage therethrough of incoming blood flow.
[0043] According to some embodiments of the invention, the embolic material is having a
diameter that equals to or greater than a predetermined size. According to some embodiments
of the invention, the predetermined size is within the range of between 20 micrometers
and 60 micrometers.
[0044] According to some embodiments of the invention, the kit is configured for collecting
an embolic material in the form of: beads, foam, and gel. According to some embodiments
of the invention, the catheter is an embolization microcatheter configured to reduce
reflux of the embolic material, during continuous delivery thereof in a subject.
[0045] According to some embodiments of the invention, the embolization microcatheter comprises:
a tubular wall having a proximal wall end, a distal wall end, and a lumen extending
between the wall ends, the lumen is opened to a distal outlet at the distal wall end
and to a plurality of side openings distributed around or/and along a section of the
tubular wall proximally to the distal outlet; the embolization microcatheter is configured
to deliver an infusion suspension of the embolic material in an infusion fluid, via
the lumen to the distal outlet; wherein the distal outlet is shaped or/and sized to
allow passage therethrough of the infusion suspension of the infusion fluid and the
embolic material, and each of the side openings is shaped or/and sized to allow passage
therethrough of the infusion fluid without the embolic material and to block passage
therethrough of the embolic material.
[0046] According to some embodiments of the invention, at least one of the side openings
comprises a slit with a gap having a maximal cross sectional dimension less than a
minimal diameter of the embolic material. According to some embodiments of the invention,
at least one of the side openings comprises a pore having a maximal cross sectional
dimension less than a minimal diameter of the embolic material. According to some
embodiments of the invention, the kit further comprises a vial containing the embolic
material.
[0047] Unless otherwise defined, all technical or/and scientific terms used herein have
the same meaning as commonly understood by one of ordinary skill in the art to which
the invention pertains. Although methods and materials similar or equivalent to those
described herein can be used in the practice or testing of embodiments of the invention,
exemplary methods or/and materials are described below. In case of conflict, the patent
specification, including definitions, will control. In addition, the materials, methods,
and examples are illustrative only and are not intended to be necessarily limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0048] Some embodiments of the invention are herein described, by way of example only, with
reference to the accompanying drawings. With specific reference now to the drawings
in detail, it is stressed that the particulars shown are by way of example and for
purposes of illustrative discussion of embodiments of the invention. In this regard,
the description taken with the drawings makes apparent to those skilled in the art
how embodiments of the invention may be practiced.
[0049] In the drawings:
FIG. 1 is a flow diagram illustrating an exemplary method of performing an embolization
therapy while preventing non-target deposition of embolic material in a non-target
organ, in accordance with some aspects of the present disclosure, which are not part
of the invention,
FIGs. 2A - 2H are schematic side cut views representing possible scenarios of implementing
exemplary embodiments of a method for applying an entrapping device within a right
atrium, in accordance with some aspects of the present disclosure, which are not part
of the invention,
FIGs. 3A - 3G are schematic illustrations showing a microcatheter for delivering embolic
material within a blood vessel of a target organ provided with means for disturbing
a retrograded flow, and an entrapping device for filtering and entrapping microparticles,
infiltrated from the delivered embolic material, deployed from within a non-target
organ, in accordance with some embodiments of the invention;
FIGs. 4A - 4G are schematic illustrations showing a microcatheter for delivering embolic
material within a blood vessel of a target organ provided with means for disturbing
a retrograded flow, and an entrapping device for filtering and entrapping microparticles,
infiltrated from the delivered embolic material, deployed at a non-target vessel downstream
to a target organ, in accordance with some embodiments of the invention;
FIGs. 5A - 5B are schematic side cut views of exemplary embodiments of a microcatheter
during delivery of an embolic material before (FIG. 5A) and after (FIG. 5B) occurrence
of a retrograded flow, in accordance with some embodiments of the invention;
FIG. 6 is a schematic top view of an exemplary embodiment of an embolic material flow
disruption section having openings in form of slits, in accordance with some embodiments
of the invention;
FIGs. 7A - 7B are schematic side cut views of exemplary embodiment of a microcatheter
including a plurality of projections, during delivery of embolic material (e.g., embolization
material or/and contrast enhancing material) before (FIG. 7A) and after (FIG. 7B)
occurrence of a retrograded flow, in accordance with some embodiments of the invention;
and
FIGs. 8A - 8D are schematic partial side cut views of exemplary embodiments of different
exemplary projections of an embolic material flow disruption section, in accordance
with some embodiments of the invention.
DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION
[0050] The present invention, in some embodiments thereof, relates to devices and kits for
preventing non-target microparticles deposition and embolization, in conjunction with
delivering microparticles (e.g., an embolization material) via a blood vessel to a
target bodily part. Some embodiments of the invention relate to devices for entrapping
infiltrated microparticles within the heart right atrium. Some embodiments of the
invention are applicable for: (i) delivering embolization material in a small blood
vessel towards a target bodily part, (ii) performing local embolization in a small
blood vessel feeding a (possibly, cancerous) target bodily part, thereby forming emboli
in small blood vessels; and (iii) capturing infiltrated microparticles within a non-target
body organ or within a blood vessel, downstream to the target organ.
[0051] It is understood that the invention is not limited to the particular methodology,
protocols, and reagents, etc., described herein, as these may vary as the skilled
artisan will recognize. It is also to be understood that the terminology used herein
is used for the purpose of describing particular embodiments only, and is not intended
to limit the scope of the invention. The following exemplary embodiments may be described
in the context of exemplary embolization procedures for ease of description and understanding.
However, the invention is not limited to the specifically described devices and may
be adapted to various clinical applications without departing from the overall scope
of the invention. It is also to be understood that the invention is not necessarily
limited in its application to any particular sequential ordering of method steps or
procedures, or to particular details of construction or/and arrangement of device
or apparatus components set forth in the following illustrative description. The invention
is capable of other embodiments or of being practiced or carried out in various ways.
[0052] Radioembolization is a common technique for treating hepatic neoplasms. Utilizing
the dual hepatic blood supply, a therapeutic radiation dose, greater than 200 Gy may
be delivered to tumors. Nevertheless, serious adverse effects caused by non-target
deposition of radioactive microspheres are associated with current implementations
of radioembolization. Non-target embolization and non-target deposition of radioactive
microparticles within lungs are considered a main concern and are primarily associated
with the creation of arteriovenous shunts that bypass the hepatic capillary bed and
drain into the blood circulation. The phenomenon of increased pulmonary shunting is
most frequently encountered in patients with advanced hepatocellular carcinoma. This
type of patient population will commonly be prohibited from receiving treatment due
to the high lung shunt fraction.
[0053] A further adverse effect associated with embolization therapy relates to retrograded
flow (backflow or reflux) of the embolization material during injection thereof within
a blood vessel. Embolic material backflow may infiltrate and accumulate within adjacent,
upstream non-target organs or/and blood vessel, and cause serious complications.
[0054] Some embodiments of the present invention may provide a solution to phenomena of
non-target deposition of embolic material or/and non-target embolization caused by
either or both reflux and blood vessels shunting.
[0055] An aspect of some embodiments of the present invention relates to entrapping means
or devices configured to entrap an embolic material (e.g., microparticles) and to
methods for using same in preventing or minimizing non-target deposition of embolic
material following an embolization therapy.
[0056] According to some embodiments, the present invention relates to microparticles entrapping
means or devices and methods for using same in preventing or minimizing infiltration
of embolization material from the liver to the lungs.
[0057] A further aspect of some aspects of the present disclosure, which are not part of
the invention, relates to an embolization procedure with two layers of protection
from non-target embolic material deposition that includes: i) positioning microparticles
entrapping device within a non-target body organ or blood vessel; and ii) performing
an embolization therapy with means applied to reduce reflux or backflow of the embolization
material. This approach affords particularly safe embolization therapy aimed to prevent
non-target deposition of microparticles caused by either or both the shunting and
reflux phenomena.
[0058] In view of the above and as will be further described below, some embodiments of
the present invention may provide a solution to the problem of non-target deposition
of microparticles or/and non-target embolization, as well as providing kits, devices,
and methods for performing techniques associated with microparticles administration,
such as radioembolization, in an effort to improve therapeutic efficiency and safety.
[0059] Some aspects of the present disclosure, which are not part of the invention, concern
the use of an embolic material entrapping device configured to be positioned before
or within a non-target body organ or a blood vessel, downstream to a target body organ,
with the use of a microcatheter that is configured to deliver microparticles, such
as in a form of an infusion suspension.
[0060] The disclosure, which is not part of the invention, concerns, in some embodiments,
the use of microparticles entrapping device configured to be positioned within the
right atrium of the heart and a microcatheter configured to deliver a pharmaceutical
composition or an infusion suspension, including microparticles and an infusion fluid.
[0061] According to some embodiments, the terms "pharmaceutical composition including microparticles"
and "infusion suspension including microparticles " are used in conjunction and refer
to an embolic material being provided within a carrier, excipient or an injectable
infusion fluid.
[0062] As used herein, the terms "embolization material" and "embolic material" are used
in conjunction and relate to materials, particles, or microparticles that can occlude
a blood vessel. Embolization material, may present different forms, and may include,
without limitation, beads, foam or glue. Embolization material, may be made from a
material, including, but not limited to, a metal or/and a polymer, or/and a glass.
Exemplary materials for producing embolization materials, include, without limitation
polyvinyl alcohol (PVA), acrylamido polyvinyl alcohol, a hydrogel coated with Polyzene-F,
two monomers that combine to form a copolymer (e.g., Ethylene vinyl alcohol copolymer
(EVOH); Onyx), silicon dioxide (SiO2), sodium oxide (Na2O), sodium carbonate (Na2CO3),
calcium oxide (CaO), silver, gold, palladium, platinum, tantalum (e.g. tantalum oxide),
tungsten, iridium, titanium, magnesium, strontium, zinc, lanthanum, barium (e.g. barium
sulfate), and stainless steel.
[0063] Optionally, certain substances may be added to the microparticles or the embolization
materials, to enhance the therapeutic effect. Examples include, but are not limited
to: pharmaceuticals (e.g., chemotherapeutics), and radioactive agents (e.g., ytrrium90).
[0064] As used herein the term "entrapping device" is interchangeable with the term "entrapping
mean(s)" relates to means that entrap, capture or/and filter embolic material having
a particular diameter within the range of 10 µm and 1,500 µm, 10 µm and 1,000 µm,
10 µm and 500 µm, 10 µm and 100 µm, 20 µm and 80 µm, or 20 µm and 60 µm. Each possibility
represents a separate embodiment of the invention.
[0065] As used herein the term "preventing" refers to total preclusion, as well as to diminishing,
minimizing, reducing, abolishing or abrogating non-target deposition of an embolic
material. In some embodiments, non-target deposition of embolic material is completely
abolished or prevented. In some embodiments, non-target deposition of embolic material
is reduced by at least 10%, at least 20%, at least 30%, at least 40%, at least 50%,
at least 60%, at least 70%, at least 80%, or at least 90%. Each possibility represents
a separate embodiment of the invention.
[0066] As used herein the terms "target organ" or "target bodily organ" relates to any body
organ or tissue that is chosen for treatment or/and is afflicted with a disease or
condition that may be treated by therapy that includes an embolization therapy. The
term specifically refers to body organs afflicted with a disease or condition that
may benefit from an embolization therapy. Exemplary diseases include, without limitation,
cancer, hemorrhage and arteriovenous malformation (AVM). Exemplary body organs include,
without limitation, liver, kidney, uterus, brain, and prostate. In contrary, the terms
"non-target organ" or "non-target bodily organ" will refer herein to organs that may
be prone to embolic material infiltration due to the embolization therapy or/and which
are chosen for particular protection by the medical practitioner.
[0067] In exemplary embodiments, entrapping, capturing or/and filtering may be temporary,
optionally, until end of an embolization therapy procedure, until withdrawal of the
microparticles entrapping device from the non-target body organ or blood vessel, or
following a chosen time, after ceasing of delivering the embolic material. According
to some embodiments, chosen time is sufficient for allowing the entrapping device
to entrap infiltrating embolic material.
[0068] As used herein the term "chosen time" may be any time, following which the practitioner
ceases delivering an embolic material. According to some embodiment, the chosen time
is within the range of 1 minute to 20 minutes, 1 minute to 10 minutes, or 1 minute
to 5 minutes. Each possibility represents a separate embodiment of the invention.
[0069] According to some embodiments, the invention is applicable for filtering or entrapping
microparticles (e.g., of an embolic material) infiltrated, for example, towards or
into the right atrium from any target organ, following treatment of the organ with
embolic material. The entrapping device of the invention is most useful in capturing
embolic material infiltrated to the blood circulation (i.e., the inferior vena cava
or the superior vena cava) from an organ blood outflow, following an embolization
procedure. Exemplary diseases that may be treated with an embolization therapy include,
without limitation, cancer that has spread (metastasized) to the liver from a primary
tumor elsewhere (e.g., colorectal cancer, breast cancer, lung cancer and neuroendocrine
tumors), cancer originating in the liver (such as hepatocellular carcinoma and cholangiocarcinoma),
renal tumors (benign and malignant), tumor within the uterine (e.g., uterine fibroid),
a brain cancer (e.g. meningioma), a prostate cancer and a colorectal cancer.
[0070] An exemplary treatment site may include the liver, where deposition of embolic material
and embolization may occur by embolization material infiltration to the lungs via
arterivenous shunts.
[0071] As used herein the term "a blood vessel, downstream to the target organ" is interchangeable
with the term "non-target blood vessel" and refers to a vessel to which blood drains
from a target body organ or a target body organ outflow blood vessel. A blood vessel,
downstream to the target organ is selected from: an organ outflow blood vessel, an
inlet of a non-target organ, or a junction of two or more organ outflow blood vessels.
[0072] An organ outflow blood vessel may, according to some embodiments, be a hepatic vein
or an inferior vena cava. An inlet of a non-target organ may, according to some embodiments,
be an inlet opening of the right atrium. A junction of two or more organ outflow blood
vessels may, according to some embodiments, be a junction between an inferior vena
cava and a hepatic vein.
[0073] Reference is now made to FIG. 1 of a flow diagram illustrating an exemplary method
of performing an embolization therapy while preventing non-target deposition of embolic
material in a non-target organ. As shown in FIG. 1, in a non-limiting manner, and
in some embodiments, the method includes the following exemplary steps (procedures
/ processes).
[0074] At exemplary step 100, an entrapping device (for example, as illustratively described
below) is inserted and localized within a non-target organ or in a blood vessel, downstream
to a target organ. At exemplary step 102, there is expanding or deploying the entrapping
device or/and a filter included therein to an expanded configuration. At exemplary
step 104, a microcatheter, for delivering embolization material, is inserted into
a blood vessel feeding a target bodily organ. At exemplary step 106, a suspension
including microparticles is injected via the microcatheter towards the body organ
via the blood vessel to thereby facilitate a blood vessel occlusion. In exemplary
embodiments, each or both steps 100 and 102 may occur in conjunction with (prior,
concomitantly or after) each or both steps 104 and 106. At exemplary step 108, microparticles,
if infiltrated from the treated (target) body organ to the blood circulation feeding
the heart, are then filtered, collected, or/and captured by the entrapping device,
optionally in a pocket formed with the filter.
[0075] Upon completion of at least one of: infusing the embolization material to the body
organ (step 106), and retrieval of the microcatheter from the blood vessel out of
the body (step 110), the entrapping device is collapsed and withdrawn back into the
delivery sheath or/and catheter and removed from the body organ or blood vessel, downstream
to a target organ, together with the captured embolic debris (step 112).
[0076] Additional details and features of the method of performing an embolization therapy
while preventing non-target deposition of embolic material in a non-target organ,
are provided hereinbelow following description of exemplary embodiments of an embolic
material (e.g., particles) entrapping device.
[0077] According to an aspect of the invention, which is not part of the invention, there
is provided an entrapping device for entrapping an embolic material infiltrated to
blood flow following delivery thereof into a blood vessel feeding a target organ,
the entrapping device includes a filter configured for filtering and entrapping the
embolic material.
[0078] According to some aspects, which are not part of the invention, the entrapping device
may be positioned within a non-target body organ or blood vessels. The entrapping
device may be positioned to cover an inlet opening of the right atrium. As used herein
the term "inlet opening of the right atrium" may be one of: i) the position where
the inferior vena cava enters the right atrium; and ii) the position where the superior
vena cava enters the right atrium. In accordance with those embodiments, the entrapping
device is configured to cover such inlet opening of the RA.
[0079] According to some aspects, which are not part of the invention, the entrapping device
may be used, positioned and deployed within a blood vessel, downstream to the target
organ.
[0080] FIGs. 2A - 2H shows an entrapping device 300 which includes a filter 308, and a filter
collapsing mechanism 305 sized for positioning in a catheter lumen of a filter delivering
catheter 304. Filter collapsing mechanism 305 is actuatable with a proximal end thereof
from outside the subject body. According to some embodiments, entrapping device 300
may be used, positioned and deployed within the non-target body organ or in a non-target
vessel using a suitable delivery system.
[0081] The delivery system may include at least one of: filter delivery catheter 304, a
delivery sheath 302, and a guidewire 306. The delivery sheath 302 and catheter 304
may include a proximal end, a distal end and a lumen extending therebetween the ends
and opened at proximal and distal ends. The guidewire 306 may be in the form of a
cord. According to some embodiments, at least one of delivery sheath 302 and catheter
304 is configured to house entrapping device 300 when in a compressed or/and collapsed
configuration.
[0082] According to some aspects, which are not part of the invention, the filter collapsing
mechanism 305 includes an elongated body 314 configured for slideably passaging through
and beyond a longitudinal axis of the delivery sheath 302 or catheter 304. Elongated
body 314 may be rod or a tube and may be distally attached to filter 308. According
to some embodiments, the guidewire 306 facilitates access and delivery of the delivery
sheath 302 or/and catheter 304 towards and into the right atrium or the vena cava
or any other non-target blood vessel or body organ.
[0083] According to some embodiments, the filter delivery catheter 304 is about 3 mm or
less in outer diameter, optionally 0.5 mm to 2 mm. According to some embodiments,
the catheter is about 150 cm long.
[0084] According to some embodiments, the entrapping device 300 is collapsible. According
to some the elongated body. In accordance with this embodiment, the entrapping device
300 has compressible or/and collapsible or/and self-expandable geometry. According
to some embodiments, the entrapping device 300 is elastic and flexible generally along
and about a central longitudinal axis of the catheter. According to some embodiments,
the entrapping device 300 is automatically deployable to seal a non-target body organ
or blood vessel (e.g., an interior wall or opening of the right atrium). According
to some embodiments, the entrapping device is configured for intimate contact with
the non-target body organ or blood vessel (e.g., an interior wall or opening of the
right atrium), for the primary purposes of filtration of embolization material, but
allows the passage of blood therethrough.
[0085] According to the invention, filter collapsing mechanism 305 further includes a circumferential
hollow sleeve 310 proximally attached to an opened perimeter of the filter 308. According
to some embodiments, the sleeve 310 may include a drawstring 312 for use in forcibly
collapsing, or elongating, or reducing the shape and profile of the filter subsequent
to deployment and use thereof.
[0086] According to some embodiments, when unrestrained, the filter 308 normally returns
to its original unstressed shape. According to some embodiments, the device is suitable
for self-expansion of the filter 308 when emerging from within a catheter 304 or delivery
sheath 302.
[0087] According to some embodiments, filter 308 is configured for expanding, and additionally
configured for collapsing in response to conformation thereof to outside boundaries
of different sizes.
[0088] According to some embodiments, filter 308 includes one or more mesh or woven filtration
layers. According to some embodiments, the filter includes a fine mesh having strands
with a thickness of no more than 200 micrometers, 150 micrometers, 100 micrometers,
50 micrometers, 25 micrometers, 10 micrometers, or 5 micrometers. Each possibility
represents a separate embodiment of the invention. According to some embodiments,
the filter 308 including pores configured to entrap embolic material having a diameter
that equals to or above a predetermined size. According to some embodiments, the predetermined
size is 20 micrometers or above or 30 micrometers above. Each possibility represents
a separate embodiment of the invention.
[0089] According to some embodiments, the shape of the filter 308 exhibits a half circle,
a cone, a cap shape, or a bowl shape. According to some embodiments, the filter 308
is opened to an umbrella or a parachute like shape. According to some embodiments,
the maximal diameter of the filter 308 when is in the open configuration is 10 mm
to 50 mm. According to some embodiments, the filter includes pores with a pore size
of about 500 micrometers or less, about 400 micrometers or less, about 300 micrometers
or less, about 200 micrometers or less, about 100 micrometers or less, about 80 micrometers
or less, about 70 micrometers or less, about 60 micrometers or less, about 50 micrometers
or less, about 45 micrometers or less, about 40 micrometers or less, about 35 micrometers
or less, or about 30 micrometers or less or about 25 micrometers or less. Each possibility
represents a separate embodiment of the invention. According to some embodiments,
the filter 308 includes pores with a pore size between the range of 10 micrometers
and 500 micrometers, 10 micrometers and 400 micrometers, 10 micrometers and 300 micrometers,
10 micrometers and 200 micrometers, 10 micrometers and 100 micrometers, 15 micrometers
and 80 micrometers, 15 micrometers and 60 micrometers, 15 micrometers and 50 micrometers,
15 micrometers and 40 micrometers, or 15 micrometers and 30 micrometers. Each possibility
represents a separate embodiment of the invention.
[0090] The filter may be formed of a polymeric material including, but not limited to polypropylene
(PP), polyvinylchloride (PVC), polyamide (nylon), polyurethane, polyester, polyethylene
tetraphalate, polyether-ether ketone (PEEK), polyether block amide (PEBA), polytetraflouroethylene
(PTFE), or any mixture, blend or combination thereof. Alternatively, or additionally,
the filter may be formed from a metal or metal alloy including, but not limited to
stainless steel, nickel-titanium alloy (Nitinol), platinum or cobalt chrome.
[0091] Reference is again made to FIG. 1 of a flow diagram illustrating an exemplary method
of performing an embolization therapy while preventing non-target deposition of embolic
material in a non-target organ, which is not part of the invention.
[0092] The method includes exemplary step 100, in which the herein disclosed entrapping
device is inserted and localized within a non-target organ (e.g., in the right atrium)
or in a blood vessel, downstream to a target organ (e.g., within the inferior vena
cava, above the hepatic veins or at a junction between the inferior vena cava and
the hepatic vein). According to exemplary aspects, which are not part of the invention,
the entrapping device is inserted to and localized at the RA. In accordance with those
embodiments, aspects, which are not part of the invention, the entrapping device may
be inserted and localized within the RA when provided with catheter delivery system
being introduced to the jugular vein and then to the superior vena cava and thereafter
localized within the RA. Alternatively, the entrapping device may be introduced to
the RA, when provided within a delivery system that is firstly introduced to the femoral
vein, and then to the inferior vena cava and thereafter localized within the RA. As
will be explained in more details below, delivery system may include at least one
of: a delivery sheath, a guidewire and a catheter for guiding and facilitating safe
and efficient delivery of the entrapping device at the non-target organ or in a blood
vessel, downstream to a target organ. Optionally, or additionally a delivery of contrast
enhancement material is injected within a blood vessel through which the catheter
should be introduced, for example, in order to verify correct anatomy and positioning.
The catheter thereafter follows the guidewire path within the body until localizing
at the appropriate position.
[0093] The method further includes exemplary step 102 of expanding or deploying the entrapping
device or/and a filter included therein to an expanded configuration. The entrapping
device may be deployed after retracting the catheter proximally to reveal the entrapping
device, or may be pushed distally out of the catheter. The entrapping device or/and
the filter is thus automatically or self-deployed in outwardly directed expansion.
Such expansion causes contact of the filter with a non-target organ blood vessel inlet
or a wall of a blood vessel, downstream to a target organ. When the entrapping device
is to be employed within the RA, the filter is positioned to cover an inlet of the
right atrium through the interior of the right atrium. The RA inlet may be an inlet
of the superior vena cava or of the inferior vena cava. When the filter is in the
open configuration, the entrapping device is incorporated in a general filtration
process, whereby embolization materials may be collected if flowing towards or/and
into the RA after infiltrating from target organ.
[0094] The method further includes exemplary step 104 whereupon a microcatheter, for delivering
embolization material, is inserted into a blood vessel feeding a target bodily organ.
Optionally, or additionally, a delivery of contrast enhancing material is injected
in the target blood vessel in order to verify correct anatomy and positioning. According
to some aspects, which are not part of the invention, and when a blood vessel feeding
the liver is to be treated, the microcatheter is inserted in the femoral artery and
through the hepatic artery to a target blood vessel.
[0095] At exemplary step 106, a suspension including microparticles is injected via the
microcatheter towards the body organ via the blood vessel to thereby facilitate a
blood vessel occlusion. It is to be noted that each or both steps 100 and 102 may
occur in conjunction with (prior, concomitantly or after) each or both steps 104 and
106.
[0096] At exemplary step 108, microparticles, if infiltrated from the treated (target) body
organ to the blood circulation feeding the heart are then filtered, collected, or/and
captured by the entrapping device, optionally in a pocket formed with the filter.
[0097] Upon completion of at least one of: infusing the embolization material to the body
organ (step 106), and retrieval of the microcatheter from the blood vessel out of
the body (step 110), the entrapping device is collapsed and withdrawn back into the
delivery sheath or/and catheter and removed from the body organ or blood vessel, downstream
to a target organ, together with the captured embolic debris (step 112). Device collapsing
is made over the entire amount of entrapped microparticles, and is performed either
selectively outside delivery sheath or/and lumen or by forcing it into the delivery
sheath or/and lumen. In accordance with this embodiment, the entrapping device is
reshaped to the original configuration following trapping the embolization material.
It is to be noted that step 110 may be conducted after, concomitantly with or before
step 112.
[0098] Reference is now made to FIGs. 2A - 2H which show schematic side cut views representing
possible scenarios of implementing exemplary embodiments of a method for applying
entrapping means within a right atrium for preventing non-target embolization or/and
deposition of an embolization material. The figures present the use of an entrapping
device 300, and a delivery system including at least one of: a delivery sheath 302,
a catheter 304, and a guidewire 306. The entrapping device 300 includes a filter 308
for entrapping microparticles above a predetermined size, while allowing blood flow
to pass therethrough. The entrapping device may further include a circumferential
hollow sleeve 310 attached to an opened perimeter of filter 308. Circumferential hollow
sleeve 310 is configured for housing at least one drawstring 312, configured for facilitating
at least one of: deployment, closure, or collapsing of the entrapping device 300.
[0099] Optionally, additionally or alternatively, the entrapping device 300 includes an
elongated member 314 distally attached to filter 308 or to circumferential hollow
sleeve 310. Elongated member 314 is configured to house within an inner lumen thereof,
drawstring 312. The entrapping device 300 is self-deployed, following proximal retrieval
of the catheter 304 or/and the delivery sheath 302, or/and following distal pushing
elongated member 314 out of the catheter 304 or/and delivery sheath 302, to employ
expansion and localization thereof within an inlet opening of the RA.
[0100] The entrapping device 300 is sized and shaped to adapt an umbrella, a parachute-like
structure, a cap shape or a cone shape. FIG. 2A shows a step of positioning distal
end of a guidewire 306 within a right atrium RA in a heart, before applying targeted
embolization treatment to a liver. FIG. 2B shows a step of positioning a distal opening
of a delivery sheath 302 in right atrium RA following passing thereof over guidewire
306. Guidewire 306 may then be withdrawn leaving delivery sheath 302 in-place. Catheter
304 may then be introduced within a lumen of delivery sheath 302, and delivery sheath
302 may stay in place or be withdrawn, leaving catheter 304 in place (shown in FIG.
1C).
[0101] Alternatively, entrapping device 300 may be independently inserted within delivery
sheath 302 (not shown). FIG. 1D shows a result of retrieval of the catheter 304 or/and
the delivery sheath 302, or/and distal pushing elongated body 314 through lumen and
distal opening of catheter 304 or/and delivery sheath 302 into right atrium RA, whereby
entrapping device 300 self-expands. FIG. 1E shows a step of deploying entrapping device
300 above right atrium inlet opening, covering it entirely, so that no embolization
bead above a predetermined threshold size could infiltrate through (in accordance
with mesh opening size). In some embodiments, embolization treatment in the liver
may begin once entrapping device 300 is deployed, optionally using any of the microcatheters
or/and any of the methodologies described herein. FIG. 2F shows filtering or entrapping
infiltrated embolization material EM within the RA with entrapping device 300. FIG.
1G shows filter 308 enclosure over entrapped embolic material EM, by proximal pulling
drawstring 312, thereby forming a pocket within which EM is entrapped. Following closure
of filter 308 over microparticles, the entrapping device 300 is forcibly withdrawn
and re-collapsed back into lumen of catheter 304 or/and delivery sheath 302 by proximally
pulling, backward elongated member 314 or/and drawstring 312.
[0102] FIG. 2H shows withdrawal of the catheter 304 or/and delivery sheath 302 with entrapping
device 300 from right atrium RA.
[0103] According to an aspect of the disclosure, which is not part of the invention, there
is provided a method for delivering particles in a blood vessel feeding a target organ
in a body of a subject, the method including at least one of the following steps (not
necessarily in same order):
> positioning an entrapping device in a blood vessel, downstream to the target organ,
the entrapping device is configured to filter embolic material from blood flow, and
to entrap the embolic material;
> placing a distal outlet of a catheter in the blood vessel feeding the target organ;
> delivering the embolic material via the distal outlet in the blood vessel towards
the target organ;
> applying a flow disturbance mechanism in the blood vessel, proximally to the distal
outlet, for creating a local disturbance in blood flow thereby suppressing a retrograded
flow of the particles flowable in a proximal direction; and
> removing the entrapping device from subject body following a chosen time after ceasing
of the delivering, sufficient for allowing the entrapping device to entrap infiltrating
embolic material infiltratable in a blood vessel, downstream to the target organ.
[0104] According to another aspect of the disclosure, which is not part of the invention
there is provided a method of applying a multi-layered protection from non-target
embolization or/and non-target deposition of microparticles in a body of a subject,
the method including at least one of the following steps (not necessarily in same
order):
> positioning an entrapping device in a first anatomical location downstream to a
target organ, the entrapping device is configured to filter the microparticles from
blood flow and to entrap the microparticles;
> placing a distal outlet of a microcatheter in a second anatomical location upstream
to the target organ;
> delivering an infusion suspension including the microparticles via the distal outlet
in the second anatomical location upstream to, and towards, the target organ;
> by allowing a continuous blood flow downstream towards the target organ and away
from the target organ, applying a flow disturbance mechanism in the second anatomical
location, proximally to the distal outlet, thereby creating a local disturbance in
blood flow for suppressing a retrograded flow of the microparticles flowable upstream
to the target organ; and
> removing the entrapping device from the subject body following a chosen time, after
ceasing of the delivering, sufficient for allowing the entrapping device to entrap
infiltrating microparticles infiltratable upstream through the flow disturbance mechanism
or/and downstream to the target organ. FIGs. 3A - 3G and FIGs. 4A - 4G are schematic
illustrations showing possible sequential steps of employing the methods which are
not part of the invention and in particular, a method of applying a multi-layered
protection from non-target embolization or/and non-target deposition of microparticles
in a body of a subject. The embodiments described in FIGs. 3A - 3G are provided with
reference to an entrapping device 350 which is similar or identical in design and
configurations to the previously disclosed entrapping device 300, and is configured
to filter microparticles from blood flow and to entrap these microparticles. FIGs.
3A and 4A schematically illustrate "downstream" and "upstream" blood flow in accordance
with the embodiments of the invention. As used herein the term "downstream" refers
to the accommodation of general/normal blood flow direction, and in some occasions
from a "target organ" to a "non-target organ", and the term "upstream" refers to a
direction against the blood flow. In a particular example, "downstream" in an artery
corresponds to normal flowing direction of oxygenated blood generally towards an organ
receiving oxygen, while "upstream" in same artery means against this natural flow
(i.e. in case of abnormal retrograde flow). In presence of abnormal shunts directly
connecting arterial system with a vein (such as in the case of shunts connecting liver
blood vessels to vena cava), "downstream" can also refer to the direction from the
"target organ" towards a "non-target organ", in a blood flow therebetween, and "upstream"
shall mean the opposite from that. The FIGs. further illustrates "a target organ",
being an organ to which embolization therapy should be applied to and the term "non-target
organ", being any other organ amenable to non-target deposition of embolic material.
[0105] FIG. 3B shows: (a) positioning entrapping device 350 in a first anatomical location
(in this example, the right atrium) downstream to a target organ (in this example,
a liver), in conjunction (before, during or/and after) with (b) placing a distal outlet
131 of a microcathter 130 in a second anatomic location (in this example, a (blood)
feeding vessel, located upstream to a target organ). Entrapping device 350 has a cap-like
shape, as shown when expanded within the non-target organ (heart, right atrium), downstream
of the target organ. FIG. 4B shows introduction of a microcathter 140 within a blood
vessel, upstream to a target organ and an entrapping device 400 within a blood vessel,
downstream to the target organ. According to some embodiments, and as will be explained
hereinbelow, each of microcatheters 130 and 140 includes a flow disturbance mechanism
in a form of side openings (132 and 142, respectively), which is configured to reduce
or prevent reflux (backflow) by creating a local disturbance in blood flow thereby
suppressing a retrograded flow of embolic material flowable in a proximal direction.
FIGs. 3C and 4C show introduction of embolic material via microcatheters 130 and 140
(respectively) into a blood vessel feeding the target organ. FIGs. 3D and 4D present
blood flow disturbance (134 and 144, respectively) caused by fluid flowing out of
side openings 104 of microcatheter 100, in view of emerging of a retrograded flow
of the microparticles. FIGs. 3E and 4E show emboli within a blood vessel feeding a
target organ following embolization procedure and embolic material infiltrated via
blood vessel shunts. FIG. 3F and 4F show entrapping of infiltrated embolic material
within a non-target organ (FIG. 3F) or within a blood vessel, downstream to a target
organ (FIG. 4F). The entrapping device 300 with the entrapped embolic material is
then withdrawn from the body (FIGs. 3H and 4H).
[0106] As detailed and describes herein the method, which is not part of the invention,
assumes the use of a microcatheter for delivering an embolization material.
[0107] According to some aspects, which are not part of the invention, the microcatheter
used is configured to reduce or minimize non-target microparticles deposition caused
by reflux or backflow, of the embolization material or by shunts.
[0108] According to some embodiments, the microcatheter includes: a tubular wall including
a proximal wall end, a distal wall end, and a lumen extending between the wall ends,
the lumen is opened to a distal outlet at the distal wall end and to a plurality of
side openings distributed around or/and along a section of the tubular wall proximally
to the distal outlet;
the embolization microcatheter is configured to deliver an infusion suspension of
particles in an infusion fluid, via the lumen to the distal outlet;
wherein the distal outlet is shaped or/and sized to allow passage there through of
the infusion suspension of the infusion fluid and the particles, and each the side
opening is shaped or/and sized to allow passage there through of the infusion fluid
and to block passage there through of the particles.
[0109] FIGs. 5A - 5B schematically illustrate side cut views of exemplary embodiments of
an exemplary microcatheter 30 during delivery of embolic material 31 before (FIG.
5A) and after (FIG. 5B) occurrence of a retrograded flow. Microcatheter 30 is sized
and configured for delivering embolic material 31 in a small blood vessel towards
a target bodily part 32. Microcatheter 30 includes a single lumen 33 surrounded by
a tubular wall 34 having an outer diameter and opened at both ends. In some embodiments,
tubular wall 34 is sized for unhindered insertion into a small blood vessel, such
as a celiac or hepatic artery. In some embodiments, outer diameter of microcatheter
30 is equal to or less than about 2 mm, or equal to or less than about 1 mm. In some
embodiments, microcatheter 30 has an external diameter equal to the diameter of a
commercially available microcatheter, such as a 2.1 French catheter, or a 2.7 French
catheter, or a 2.9 French catheter.
[0110] A proximal portion of tubular wall 34 is connectable to a pressure source and to
a reservoir configured for containing an infusion suspension of an embolic material
31.
[0111] A distal portion of tubular wall ends with a tip 35, enclosing a distal outlet 36.
Tubular wall 34 distal portion includes an embolic material flow disruption section
37 configured to disrupt passage of an incoming retrograded (in a general distal direction)
flow 38 of the embolic material around tubular wall 34, during continuous delivery
of the embolic material 31 from the reservoir to tip 35 and out through distal outlet
36. As shown in FIG. 5B, flow disruption section 37 is configured to diminish, or
block, incoming retrograded flow 38 of the embolic material 31, for example, thereby
increasing local pressure thereabout or/and creating local turbulence or vortex. In
some embodiments, the turbulence or vortex is created by infusion fluid injected or
otherwise expelled from the microcatheter, for example, wherein the embolic material
31 is partially or fully filtered from the infusion fluid.
[0112] Flow disruption section 37 includes a plurality of openings 39 distributed around
or/and along it, each opening is shaped or/and sized to effect passage therethrough
of an infusion fluid (such as a viscous fluid) 40, and to block passage therethrough
of the embolic material 31. In exemplary embodiments, infusion fluid 40 includes a
contrast enhancing material (agent), for example, diluted to a certain degree such
as with saline.
[0113] One or more opening 39 includes a pore having a cross sectional dimension less than
minimal diameter of the embolic material, for example, embolization material (e.g.,
bead diameter). Such cross sectional dimension is, for example, less than about 500
microns (µm), or, equal to or less than about 100 microns (µm), or, equal to or less
than about 40 microns (µm). In exemplary embodiments, the cross section dimension
is in a range of between about 20 microns (µm) and about 30 microns (µm), for example,
about 28 microns (µm). For example, as shown, each pore is located at end of a channel
being angled (wherein the angle is an exemplary range of between about 0 degrees and
about 90 degrees) relative to a long axis of lumen 33 or/and relative to a radial
axis thereof at a cross section adjacent thereto. In exemplary embodiments, at least
two pores are angularly located in different directions such that a first stream of
the infusion suspension in immediate vicinity of a first pore at least partially intersects
a second stream of the infusion suspension in immediate vicinity of a second pore.
Openings 39 or pores may be in any possible form, for example, with circular or rectangular
cross section, or as a burst slit (i.e., opened only under chosen pressure or force),
or a constantly opened slit. In such exemplary embodiments, the openings 39 or pores
have a minimal cross sectional dimension being less than the minimal diameter of the
embolic material (e.g., embolization material, (for example, in the form of beads).
[0114] In some embodiments, lumen 33 is configured to deliver a suspension of infusion fluid
40 and embolic material 31, for example, in a form of beads. In some embodiments,
distal outlet 36 is shaped or/and sized to effect passage therethrough of the infusion
suspension of infusion fluid 40 and the embolic material (beads) 31, and at least
one side opening 39 is shaped or/and sized to effect passage therethrough of infusion
fluid 40, and to block passage therethrough of embolic material (beads) 31, for example,
if a cross sectional dimension of the pore in each opening is less than a minimal
diameter of the embolic material (beads).
[0115] In some embodiments, at least one side opening 39 is shaped or/and sized to effect
passage therethrough of infusion fluid 40, and to block passage therethrough of embolic
material (beads) 31, during flow of the infusion suspension through distal outlet
36. In some other embodiments, at least one side opening 39 is shaped or/and sized
to effect passage therethrough of infusion fluid 40, and to block passage therethrough
of embolic material (beads) 31, during conditions when the infusion suspension is
blocked or interrupted from flowing through distal outlet 36.
[0116] In some embodiments, a total opened cross section of all openings 39 is equal to
or greater than a smallest cross section of lumen 33 and distal outlet 36.
[0117] In some embodiments, a farthest distal side opening 39 is located within a range
of between about 0 mm and about 20 mm, or within a range of between about 0 mm and
about 10 mm, or within a range of between about 0 mm and about 5 mm, proximally to
distal outlet 36.
[0118] FIG. 6 schematically illustrates a top view of an exemplary embodiment of an embolic
material flow disruption section 55 (included in an exemplary microcatheter 50) having
openings in form of slits. Microcatheter 50 is sized and configured for delivering
embolic material, for example, including embolization material (e.g., in a form of
beads) in a small blood vessel, towards a target bodily part. Microcatheter 50 includes
a tubular wall 52 having a distal portion which ends with a tip 53, enclosing a distal
outlet 54. Tubular wall 52 distal portion includes an embolic material flow disruption
section 55 configured to disrupt passage therethrough of an incoming retrograded flow
of the embolic material, for example, during continuous delivery of the embolic material
through distal outlet 54. Flow disruption section 55 is configured to block, or/and
cause turbulence in, incoming retrograded flow of the embolic material, thereby increasing
local pressure thereabout.
[0119] Flow disruption section 55 includes a plurality of openings 56 distributed around
or/and along it, each opening includes a slit with a gap having a cross sectional
dimension (e.g., width) less than minimal diameter of the embolic material. In exemplary
embodiments, another cross sectional dimension of this gap (e.g., length) is substantially
greater than the minimal diameter of the embolic material. In some embodiments, each
opening is shaped or/and sized to effect passage therethrough of an infusion fluid,
and to block passage therethrough of the embolic material.
[0120] In some embodiments, flow disruption section 55 includes material being firmer than
material of other sections of tubular wall 52 distal portion. In exemplary embodiments,
flow disruption section 55 is made of a metallic material, a hard polymeric material,
or a combination thereof. In exemplary embodiments, flow disruption section 55 is
coated with a radiopaque material such as with hydrophilic coating. In exemplary embodiments,
flow disruption section 55 is structured with a metal coil, for example, impregnated
with solid structure or/and attached to a layer of solid structure.
[0121] FIGs. 7A - 7B schematically illustrate side cut views of exemplary embodiments of
a microcatheter 60 including a plurality of projections, during delivery of embolic
material (e.g., embolization material) before (FIG. 7A) and after (FIG. 7B) occurrence
of a retrograded flow. Microcatheter 60 is sized and configured for delivering the
embolic material, for example, embolization material (e.g., in a form of beads) in
a small blood vessel, towards a target bodily part. Microcatheter 60 includes a tubular
wall 61 having a distal portion which ends with a tip 62, enclosing a distal outlet
63. In some embodiments, tubular wall 61 is sized for unhindered insertion into a
small blood vessel, such as a celiac or hepatic artery.
[0122] Tubular wall 61 distal portion includes an embolic material flow disruption section
64 configured to disrupt passage of an incoming retrograded flow of the embolic material,
during continuous delivery of the embolic material through distal outlet 63. Flow
disruption section 64 is configured to diminish, block, or/and cause turbulence or
vortex in, incoming retrograded flow of the embolic material in a distal direction
around Tubular wall 61 distal portion adjacent thereto, and optionally increase local
pressure thereabout.
[0123] Flow disruption section 64 includes a plurality of projections 65 branching out from
and distributed around or/and along it. In exemplary embodiments, projections 65 are
flexible or/and configured to bend proximally into a straight form along tubular wall
61 distal portion when flow disruption section 64 is passed distally within a closely
fitting outer tube. In exemplary embodiments, projections 65 are curled distally towards
tip 62 when in a relaxed configuration such as in absence of retrograded flow.
[0124] FIGs. 8A - 8D schematically illustrate partial side cut views of exemplary embodiments
of different exemplary projections of an embolic material flow disruption section.
FIG. 8A shows projections 66 in a form of threads angled distally at least when in
relaxed configuration, FIG. 8B shows projections 67 in a form of threads angled proximally
at least when in relaxed configuration, FIG. 8C shows projections 68 in a form of
prongs, and FIG. 8D shows projections 69 in a form of bulges, for example, as a result
of a coil wounded over the low disruption section.
[0125] Each of the following terms written in singular grammatical form: 'a', 'an', and
'the', as used herein, means 'at least one', or 'one or more'. Use of the phrase 'one
or more' herein does not alter this intended meaning of 'a', 'an', or 'the'. Accordingly,
the terms 'a', 'an', and 'the', as used herein, may also refer to, and encompass,
a plurality of the stated entity or object,
unless otherwise specifically defined or stated herein, or,
unless the context clearly dictates otherwise. For example, the phrases: 'a unit', 'a device', 'an assembly', 'a mechanism', 'a
component', 'an element', and 'a step or procedure', as used herein, may also refer
to, and encompass, a plurality of units, a plurality of devices, a plurality of assemblies,
a plurality of mechanisms, a plurality of components, a plurality of elements, and,
a plurality of steps or procedures, respectively.
[0126] Each of the following terms: 'includes', 'including', 'has', 'having', 'comprises',
and 'comprising', and, their linguistic / grammatical variants, derivatives, or/and
conjugates, as used herein, means 'including, but not limited to', and is to be taken
as specifying the stated component(s), feature(s), characteristic(s), parameter(s),
integer(s), or step(s), and does not preclude addition of one or more additional component(s),
feature(s), characteristic(s), parameter(s), integer(s), step(s), or groups thereof.
Each of these terms is considered equivalent in meaning to the phrase 'consisting
essentially of.
[0127] Each of the phrases 'consisting of' and 'consists of, as used herein, means 'including
and limited to'.
[0128] The phrase 'consisting essentially of, as used herein, means that the stated entity
or item (system, system unit, system sub-unit, device, assembly, sub-assembly, mechanism,
structure, component, element, or, peripheral equipment, utility, accessory, or material,
method or process, step or procedure, sub-step or sub-procedure), which is an entirety
or part of an exemplary embodiment of the disclosed invention, or/and which is used
for implementing an exemplary embodiment of the disclosed invention, may include at
least one additional 'feature or characteristic' being a system unit, system sub-unit,
device, assembly, sub-assembly, mechanism, structure, component, or element, or, peripheral
equipment, utility, accessory, or material, step or procedure, sub-step or sub-procedure),
but only if each such additional 'feature or characteristic' does not materially alter
the basic novel and inventive characteristics or special technical features, of the
claimed entity or item.
[0129] The term 'method', as used herein, refers to steps, procedures, manners, means, or/and
techniques, for accomplishing a given task including, but not limited to, those steps,
procedures, manners, means, or/and techniques, either known to, or readily developed
from known steps, procedures, manners, means, or/and techniques, by practitioners
in the relevant field(s) of the disclosed disclosure, which is not part of the invention.
[0130] Throughout this disclosure, a numerical value of a parameter, feature, characteristic,
object, or dimension, may be stated or described in terms of a numerical range format.
Such a numerical range format, as used herein, illustrates implementation of some
exemplary embodiments of the invention, and does not inflexibly limit the scope of
the exemplary embodiments of the invention. Accordingly, a stated or described numerical
range also refers to, and encompasses, all possible sub-ranges and individual numerical
values (where a numerical value may be expressed as a whole, integral, or fractional
number) within that stated or described numerical range. For example, a stated or
described numerical range 'from 1 to 6' also refers to, and encompasses, all possible
sub-ranges, such as 'from 1 to 3', 'from 1 to 4', 'from 1 to 5', 'from 2 to 4', 'from
2 to 6', 'from 3 to 6', etc., and individual numerical values, such as '1', '1.3',
'2', '2.8', '3', '3.5', '4', '4.6', '5', '5.2', and '6', within the stated or described
numerical range of 'from 1 to 6'. This applies regardless of the numerical breadth,
extent, or size, of the stated or described numerical range.
[0131] Moreover, for stating or describing a numerical range, the phrase 'in a range of
between about a first numerical value
and about a second numerical value', is considered equivalent to, and meaning the same
as, the phrase 'in a range of
from about a first numerical value to about a second numerical value', and, thus, the
two equivalently meaning phrases may be used interchangeably.
[0132] The term 'about', as used herein, refers to ± 10 % of the stated numerical value.
[0133] It is to be fully understood that certain aspects, characteristics, and features,
of the invention, which are, for clarity, illustratively described and presented in
the context or format of a plurality of separate embodiments, may also be illustratively
described and presented in any suitable combination or sub-combination in the context
or format of a single embodiment. Conversely, various aspects, characteristics, and
features, of the invention which are illustratively described and presented in combination
or subcombination- in the context or format of a single embodiment, may also be illustratively
described and presented in the context or format of a plurality of separate embodiments.
[0134] Although the invention has been described in conjunction with specific embodiments
thereof, it is evident that many alternatives, modifications and variations will be
apparent to those skilled in the art. Accordingly, it is intended to embrace all such
alternatives, modifications and variations that fall within the scope of the appended
claims.