U.S. patent application number 10/943121 was filed with the patent office on 2005-02-10 for tissue separation method.
This patent application is currently assigned to Artemis Medical, Inc.. Invention is credited to Dubrul, William Richard, Fulton, Richard E..
Application Number | 20050033172 10/943121 |
Document ID | / |
Family ID | 27491103 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050033172 |
Kind Code |
A1 |
Dubrul, William Richard ; et
al. |
February 10, 2005 |
Tissue separation method
Abstract
A method for separating a soft tissue section from a body. An
elongate shaft, which has a lumen that carries a tubular braid, is
inserted into tissue adjacent a target tissue section. The tubular
braid has a radially compressed state and a radially expanded
state. The tubular braid is advanced from the shaft. As the tubular
braid advances beyond the distal end of the shaft, it expands to a
radially expanded state. The target tissue section is then
separated
Inventors: |
Dubrul, William Richard;
(Redwood City, CA) ; Fulton, Richard E.; (Grand
Junction, CO) |
Correspondence
Address: |
O'MELVENY & MEYERS
114 PACIFICA, SUITE 100
IRVINE
CA
92618
US
|
Assignee: |
Artemis Medical, Inc.
Hayward
CA
94545-1301
|
Family ID: |
27491103 |
Appl. No.: |
10/943121 |
Filed: |
September 15, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10943121 |
Sep 15, 2004 |
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10458406 |
Jun 10, 2003 |
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10458406 |
Jun 10, 2003 |
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09792917 |
Feb 26, 2001 |
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6602265 |
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09792917 |
Feb 26, 2001 |
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09699081 |
Oct 27, 2000 |
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6695858 |
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09699081 |
Oct 27, 2000 |
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09248088 |
Feb 9, 1999 |
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6221006 |
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60074199 |
Feb 10, 1998 |
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60105284 |
Oct 22, 1998 |
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Current U.S.
Class: |
600/439 |
Current CPC
Class: |
A61B 17/221 20130101;
A61B 2017/2215 20130101; A61B 2017/2212 20130101 |
Class at
Publication: |
600/439 |
International
Class: |
A61B 008/00 |
Claims
What is claimed is:
1. A method for separating a soft tissue section from a body
comprising: inserting an elongate shaft into tissue adjacent a
target tissue section, the elongate shaft having a lumen that
carries a tubular braid, wherein the tubular braid has a radially
compressed state and a radially expanded state; advancing the
tubular braid from the shaft, wherein the tubular braid expands to
a radially expanded state as it advances beyond a distal end of the
elongate shaft; and separating the target tissue section.
2. The method of claim 1, wherein the step of separating the target
tissue section is accomplished by activating a cutting device
associated with a distal end of the tubular braid.
3. The method of claim 1, wherein the step of separating the target
tissue section is accomplished by inserting expandable blades into
the tissue adjacent a target tissue section.
4. The method of claim 3, wherein the expandable blades separate
the target tissue section mechanically.
5. The method of claim 3, wherein the expandable blades separate
the target tissue section using thermal energy.
6. The method of claim 3, wherein the expandable blades separate
the target tissue section using vibrational energy.
7. The method of claim 3, wherein the expandable blades separate
the target tissue section using laser energy.
8. The method of claim 3, wherein the expandable blades separate
the target tissue section using electrical energy.
9. The method of claim 3, wherein the expandable blades separate
the target tissue section using radio frequency.
10. The method of claim 1, wherein the cutting device is a sharp
distal end of the tubular member, and wherein the target tissue is
separated by rotating the tubular member.
11. The method of claim 1, wherein the step of separating the
target tissue is accomplished using electrosurgery.
12. The method of claim 1, wherein the step of separating the
target tissue is accomplished using radio frequency.
13. The method of claim 1, wherein the step of separating the
target tissue is accomplished using thermal energy.
14. The method of claim 1, wherein the step of separating the
target tissue is accomplished using laser surgery.
15. The method of claim 1, wherein the step of separating the
target tissue is accomplished using electrical energy.
16. The method of claim 1, wherein the step of separating the
target tissue is accomplished using vibrational energy.
17. The method of claim 1, wherein the step of separating the
target tissue is accomplished using ultrasound energy.
18. The method of claim 1, further comprising the step of
contracting the tubular braid.
19. The method of claim 18, wherein the step of contracting the
tubular braid causes further severing of the target tissue
section.
20. The method of claim 18, further comprising the step of removing
the target tissue section from the body.
21. The method of claim 1, further comprising the step of closing
the distal end of the tubular braid.
22. The method of claim 21, further comprising the step of removing
the target tissue section from the body.
23. The method of claim 21, wherein the step of closing the distal
end of the tubular braid causes further severing of the target
tissue section.
24. The method of claim 21, wherein the tubular braid is closed
with a snare.
25. The method of claim 21, wherein the tubular braid is closed
with a drawstring.
Description
[0001] This application is a division of U.S. application Ser. No.
10/458,406, filed Jun. 10, 2003, which is a divisional of U.S.
application Ser. No. 09/792,917, filed Feb. 26, 2001, now U.S. Pat.
No. 6,602,265, which is a continuation of U.S. application Ser. No.
09/699,081, filed Oct. 27, 2000, now. U.S. Pat. No. 6,695,858,
which is a continuation of U.S. application Ser. No. 09/248,088,
filed Feb. 9, 1999, now. U.S. Pat. No. 6,221,006, which claims the
benefit of (a) Provisional Patent Application No. 60/074,199, filed
Feb. 10, 1998, and (b) Provisional Patent Application No.
60/105,284, filed Oct. 22, 1998. All of the above-mentioned patents
and applications are herein expressly incorporated by reference in
their entirety.
FIELD OF THE INVENTION
[0002] In general, this invention relates to medical devices and
methods. In particular, the instant invention relates to an
improved device for the removal of tissue or foreign bodies from
the body. One particular use of this improved device is removal of
obstructions from the tubular channels of the body. These
obstructions are usually blood clots (thrombi) or other byproducts
of occlusive vascular disease (e.g., plaque) or even
instruments/implants lost by the physician during an intervention
including but not limited to wires, stents, staples, components,
embolic coils, etc. Further, the removal of matter from
non-vascular channels is disclosed. Even further, the instant
invention can be used for the removal of tissue including but not
limited to tissue biopsies, cancerous, necrotic, infected, or other
diseased tissue from solid or semi-solid tissue.
BACKGROUND
[0003] Occlusive vascular disease is a common ailment in people
resulting in enormous costs to the health care system. Blood clots
are the most common type of occlusion. Removal of clots from the
body has been studied for several years and many techniques
(devices and methods) have been studied and practiced. One of the
more common techniques is one referred to as embolectomy.
Embolectomy is a treatment whereby the clot is removed from the
body as opposed to being dissolved and then reabsorbed. Another
alternative is thrombolysis. As the name indicates, this is lysing
(eating) of the thrombus (blood clot). Usually this requires a
significant amount of potentially dangerous and always expensive
drug that is injected into the vasculature. The drug delivery is
sometimes aided with special catheters, which may increase
efficacy, but certainly increase cost. The deposit of sinuous
plaque (arteriosclerosis) to the inner wall of arteries usually
precedes clot formation. Several expensive devices (dilatation
balloons, stents, mechanical cutters, etc.) have been introduced to
fight this vascular occlusive disease, but none of which has proven
to be the `magic bullet` to treat this ubiquitous disease. Because
of the various problems with all of the techniques and approaches
to solving this medical condition, there exists no particular
method or device that is considered the most accepted mode of
treatment.
[0004] Unfortunately, cancer too is a common ailment resulting in
over 1,500 deaths every day in the U.S. (550,000every year).
Therapy modalities for cancer are plentiful and continued to be
researched with vigor. Still, the preferred treatment continues to
be physical removal of the cancer. When applicable, surgical
removal is preferred (breast, colon, brain, lung, kidney, etc.).
Surgical removal is often extremely invasive and efforts to remove
cancerous tissue in a less invasive way continue, but have not yet
been perfected. The only cure for cancer continues to be early
diagnosis and subsequent early treatment. As cancer therapies
continue at an earlier stage of diagnosis, the cancerous tissue is
smaller and smaller. Early removal of these smaller cancers demand
new techniques for removal and obliteration that are less invasive.
The instant invention describes new devices for less invasive
cancer therapy. There are many techniques and devices known in the
art for removing blockages in the vascular system and other
passageways of the human body as well as removing other diseased
tissue.
[0005] There is a continuing need for improved devices to meet at
least the following objectives.
[0006] The first objective is to reduce cost. This is particularly
important in recent years where it is clear for safety and sanitary
reasons that these will be single use devices. A device, even
though it performs a function in some improved manner, will not be
widely used if it is considerably more costly than the alternatives
available.
[0007] A second objective is to provide a device that is simple to
use and in a very real sense simple to understand. This will
encourage its adoption and use by medical personnel. It will also
tend to keep cost low.
[0008] The third objective is to provide a device that entails a
procedure with which the medical profession is familiar so that the
skills that have been learned from previous experience will
continue to have applicability.
[0009] A fourth objective relates to the effectiveness and
thoroughness with which the biological tissue or foreign body is
removed. With regard to biological tissue removal, it is important
that an optimum amount of the mater be removed; recognizing that no
device is likely to provide one hundred percent optimization.
[0010] A fifth objective concerns safety; a matter which is often
so critical as to trump the other considerations. It is important
to avoid unnecessary tissue trauma. In the case of using the
present invention or its similar inventions in the tubular channels
of the body, it is critically important to avoid breaking up matter
in a fashion that leads to flushing elements of the blockage
throughout the body involved. The same may be true for removal of
diseased tissue removal, certainly in the case of removal of
cancerous tissue.
[0011] There are trade-offs in design considerations to achieve the
above five interrelated objectives. Extreme simplicity and a very
simple procedure might overly compromise safety. Addressing all of
these considerations calls for some trade-off between the
objectives.
[0012] Accordingly, a major object of this invention is to provide
an improved removal device that achieves the objectives of reduced
cost, enhanced simplicity, a standard procedure, high effectiveness
and a high degree of safety. Most particularly, it is an object of
this invention to achieve these objectives with an enhanced
trade-off value for the combined objectives.
[0013] For these reasons, it is desirable to provide an improved
device that may circumvent some of the problems associated with
previous techniques. This improved medical device provides a new
configuration that will eliminate some of those problems and
methods for their use, which facilitate removal of vascular
obstructions in the operating room or interventional suite.
BRIEF DESCRIPTION
[0014] In brief, one embodiment of this invention is particularly
adapted to the removal of blockages in vascular channels (biologic
or synthetic) of the body. That embodiment combines an expanding
channel catheter and a support wire having an occlusion-engaging
element.
[0015] The support wire may extend through the expandable channel
device or catheter, through or around the occlusion and at its
distal end has an annular braided element attached thereto. The
support wire is a dual element support wire having a core and an
annular shell that slides on the core. The distal end of the core
is attached to the distal end of the annular braided element and
the distal end of the shell is attached to the proximal end of the
annular braided element. Thus movement of the core and shell
relative to one another moves the braided element from a radially
retracted position which is useful for insertion through the
catheter to a radially expanded position which expands it to the
sidewall of the channel. When the annular braided element is in its
radially compressed (smaller diameter) state, it can be passed
through or around the occlusion together with the rest of the wire
to reside on the distal end of the occlusion. When the braided
element is expanded and moved proximally (that is, in a retrograde
fashion), it will engage the occlusion and force the occlusion into
the catheter. Alternatively, no motion of the engaging element may
be required if aspiration is applied. In this case, the engaging
expandable channel device acts as a seal to prevent the suction
from aspiration to remove much material beyond its point of
deployment in the channel. Further, no motion of the distal
engaging element is required if the expandable engaging element is
moved distally toward the occlusion and thusly engulfs the
obstruction by its forward motion and expandability.
[0016] The distal end of the catheter is proximal of the occlusion
and contains an expandable blocking mechanism that extends radially
from the distal end of the catheter to the wall of the graft or
body passageway. This catheter expandable blocking element also has
a radially retracted insertion state and a radially expanded
blocking state. The expandable blocking element is similar in
construction to the distal engaging element in that it is a tubular
braid, which may or may not be covered by or integrated with a thin
film or membrane.
[0017] This distal tubular braid of expandable channel device is
usually bonded to the distal end of the catheter or an integral
part of the catheter. Pushing the assembly forward where it will
meet resistance to the obstruction actuates the expandable
characteristic of the expandable engaging element. Alternatively,
there may be a mandril or drawstring that may cause the tubular
braid to expand. In this case, the distal blocking element is
expanded in a similar fashion. In this radially expanded state, the
expandable engaging element and its film (if desired) blocks the
annulus around the catheter so that the occluded blood or other
obstruction which is being removed is forced into the catheter
where it is aspirated, obliterated or otherwise removed.
[0018] The instant invention also describes another use of the same
device of the instant invention with minor changes. In this case,
the expandable tubular braid may be used as a tissue removal device
as opposed to an obstruction removal device. In other words, the
instant invention could be used for harvesting vein grafts, removal
of plaque from arteries taking biopsy samples, or removal of
diseased tissue (i.e., cancerous or other disease) from solid or
semi-solid tissue. In this case, the present invention would be
pushed forward and when it reached an expanded diameter (either by
design of the tubular braid, design of the entire expandable
assembly or by tissue constraints) it would separate tissue via the
wall of the expanded tubular device. This separation of tissue may
be aided by other energy sources such as, but not limited to
mechanical (cutting), thermal, electrical energies, etc. Once the
desired amount of tissue is removed, the expandable tubular braid
(with tissue remaining within its inner diameter) may be removed
from the body. This removal may include pulling the expanded
tubular braid element and thus putting it into a tensile
configuration, where the tubular braided element will have a
tendency to be elongated and consequently the diameter of the
expanded device may be decreased depending upon the matter
contained within as well as the physical constraints put on the
device by its particular environment within the body.
SUMMARY OF THE INVENTION
[0019] The instant invention provides an improved device of the
type having a shaft with a proximal end and a distal end. The
improvement comprises configuring at least a distal portion of the
shaft so that it can assume a shape(s) along its shaft (proximally,
mid-section or distally) that will act as a TRAP or dragger. In the
case of body channels or cavities, this trap mechanism(s) is moved
along the lumen (artery, vein, intestine, stent, graft, or other
hollow vessel or organ) and then past the obstruction or tissue
(clot, plaque, or other obstruction). Once it is past the
obstruction the user (physician/technician) can actuate the trap
mechanism(s) so that it is enlarged beyond its original
size/diameter and aid in removing the obstruction using another
novel, elongate expandable channel. This novel, expandable channel
has the ability to start small but is easily enlarged when the
obstruction or tissue meets the distal end of the device. Once the
material located in at least the distal end of this expandable
channel (and possibly farther into it) the expandable channel that
is distal to the material may shrink down to the original diameter
or close to it. In other words, this new channel acts like a snake
swallowing a large piece of food that originally is larger than the
snake's throat or intestines. For that reason, this new channel
will be referred to as PYTHON. This technique may be aided with
other aids such as the addition of lytic agents, monoclonal
antibodies. vibration, irrigation, aspiration, therapeutic
ultrasound or other energies such as mechanical, electrical,
magnetic, etc. or pharmaceutical therapy(s) that will aid with
removal or obliteration of the material. MIS (Minimally Invasive
Surgery) or LIS (Least Invasive Surgery) devices described herein
such as catheters and guide wires, for example are the most common
tools used by least invasive interventionalists today. These
devices are available in a variety of shapes and sizes from
0.008-0.500" diameters and from 6.0-80.0" in length. In other
respects, the catheters and guide wires or other device(s) of the
instant invention will have the geometries, characteristics, and
dimensions of those commonly employed for the intended purpose
(e.g., introduction to a blood vessel (LIS) or surgical tissue
removal (MIS). MIS and LIS are often interchanged in their usage.
Usually LIS refers to catheters, guide wires, (and the like) that
are used within the body, often within the channels of the body.
MIS typically refers to videoscopic surgery where miniature cameras
are used to accomplish surgery. However, because of the large
crossover of the use of these terms, the inventors do not wish to
limit the scope of the devices described herein when these terms
are used.
DESCRIPTION OF THE BACKGROUND ART
[0020] The intellectual property regarding vascular obstruction
removal is extensive. Some of the pertinent embolectomy and
atherectomy descriptions are set forth in a number of issued U.S.
patents, including U.S. Pat. Nos. 5,498,236, 5,380,273 and
5,713,848 by the inventor of the instant invention (Dubrul) as well
as U.S. Pat. Nos. 4,762,130, 5,827,729, 5,476,450, 4,998,919,
5,772,674, 5,370,653, 5,733,294, 4,762,130, 5,443,454, 5,419,774,
5,112,347, 4,030,503, 5,653,684, and 3,978,863.
[0021] U.S. Pat. Nos. 5,498,236, 5,380,273, and 5,713,848 by the
inventor of the instant invention (Dubrul) describe a Motion
Catheter that is used for `the removal and dissolution of
obstructions within the lumens of the body.` In these issued
patents, Dubrul et al. additionally discloses a filter/occluder
that is similar to the TRAP mechanism disclosed heretofore.
However, Dubrul describes the filter occluder specially to keep
particulate (e.g., emboli) from traveling downstream and causing
deleterious effects on the patient (e.g., stroke). U.S. Pat. No.
4,762,130 by Fogarty describes a spiral balloon for the removal of
blood clots (thrombus). U.S. Pat. No. 5,653,684 describes a device
that uses and expandable tubular braid on the distal end of a
catheter, but with this device the inventor uses the device to
crack atheromous plaque using radio frequency energy.
[0022] The intellectual property regarding cancer therapies and
removal is extensive as well. Some of the pertinent cancer therapy
descriptions are set forth in a number of issued U.S. patents,
including U.S. Pat. Nos. 5,368,597, 5,769,794, 5,647,372, 5,465,731
and 5,443,472.
[0023] U.S. Pat. No. 5,368,597 describes a reclosable pouch
retaining tissue. U.S. Pat. No. 5,769,794 discloses a bag for
cancerous tissue removal. U.S. Pat. No. 5,647,372 describes a
specimen retrieval pouch. U.S. Pat. No. 5,465,731 discloses a
method and device for specimen retrieval. U.S. Pat. No. 5,443,472
describes a morcellator system for diseased tissue.
[0024] Further, the pending patent application by the inventor
(Dubrul et al.) of the instant invention, Ser. No. 60/074,183, is
pertinent to the instant invention with regard to using the distal
TRAP mechanisms as an Anchor and Tensioner as well as a Detachable
Vessel Occluder.
[0025] Further U.S. Pat. No. 5,827,729 by Auth describes an
aspiration thrombectomy catheter with an angled distal end to allow
aspiration of blood clot into the catheter. Ruggio, in U.S. Pat.
No. 5,476,450, discloses an apparatus for aspirating substances
into a catheter also. U.S. Pat. No. 4,998,919 describes a catheter
designed to infuse a lytic agent and aspirate the residual clot
through a larger lumen. U.S. Pat. No. 5,772,674 describes a
thrombectomy device, which includes a delivery and receiving
catheter having balloons at their distal ends. In addition, Cragg,
in U.S. Pat. No. 5,370,653, describes a thrombectomy device with
rotating brushes.
BRIEF DESCRIPTION OF THE FIGURES
[0026] FIG. 1 is a cross sectional view of a preferred embodiment
of the instant invention, being an inflatable balloon with a
roughened surface or covering. This is one preferred embodiment of
the TRAP as disclosed herein.
[0027] FIG. 2A is a schematic view of the preferred embodiment of
the instant invention and an alternative design of the TRAP
described herein.
[0028] FIG. 2B shows a malecot type TRAP with a roughened
surface.
[0029] FIG. 2C is a cross sectional view of the malecot style TRAP
of the instant invention in its un-deployed state. Not illustrated
in FIGS. 2A, 2B and 2C is a covering, membrane, or film that could
be used over or within the ribs or wings of the malecot style TRAP.
Further, other mechanisms to change the rigidity of the mechanism
are not illustrated.
[0030] FIG. 3 is a schematic illustration of the instant invention
and yet a third alternative design of the TRAP described herein.
FIG. 3 illustrates the TRAP of the instant invention where tubular
braid is used. Not illustrated is a covering that may be over or
within the expandable TRAP.
[0031] FIG. 4 illustrates the tubular braid of the instant
invention. This expandable component is pertinent to the design of
the expandable channel illustrated in FIGS. 5, 6, 7, 8 and 9 as
well as the TRAP illustrated in FIG. 3. Not illustrated is a
covering that may be over or within the expandable channel.
[0032] FIG. 5 illustrates the expandable channel referred to as the
PYTHON in place in a tubular channel of the body in its partially
deployed condition. Not illustrated is a covering that may be over
or within the expandable channel.
[0033] FIG. 6 illustrates the PYTHON expandable channel of the
instant invention. Here the PYTHON is in its deployed condition and
has engulfed material in the vessel. Not illustrated is a covering
that may be over or within the expandable channel.
[0034] FIG. 7A illustrates the expanding channel of the instant
invention in its un-deployed state as it is entering a breast for
tissue removal. FIG. 7A shows a treatment mechanism of the instant
invention as well.
[0035] FIG. 7B illustrates the expandable channel. PYTHON, of the
instant invention whereby it is deployed and has engulfed the
tissue as well as the therapeutic mechanism. Not illustrated is a
covering that may be over or within the expandable channel.
[0036] FIG. 8A illustrates the PYTHON expandable channel of the
instant invention as it enters the breast. In FIG. 8A the PYTHON is
in its un-deployed state.
[0037] FIG. 8B illustrates the PYTHON expandable channel of the
instant invention whereby the PYTHON is deployed and has engulfed
the target tissue of the breast to be removed. Not illustrated is a
covering that may be over or within the expandable channel.
[0038] FIG. 9A illustrates the expandable channel PYTHON of the
instant invention in its un-deployed state in a tubular channel of
the body where it is about to be deployed and engulf an obstruction
within the vessel.
[0039] FIG. 9B illustrates the expandable channel. PYTHON, of the
instant invention, as it is being deployed and beginning to engulf
the obstruction.
[0040] FIG. 9C illustrates the PYTHON expandable channel of the
instant invention in its deployed state with the obstruction
engulfed within the expanded/deployed channel. Not illustrated is a
covering that may be over or within the expandable channel.
[0041] FIGS. 10A and 10B illustrate an expandable channel used to
remove a section of a vessel for harvesting purposes.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0042] FIG. 1 is a cross sectional drawing showing the device of
this invention fully deployed in an occluded channel 2. The FIG. 1
drawing shows the TRAP element at the distal end of the catheter in
its radially expanded state. It is important to note that the TRAP
element may take a variety of shapes as would be required for the
particular application. The preferred shape is likely to be an
ovoid shape. FIG. 1 is an illustration of the TRAP device using an
inflatable balloon 1. FIG. 1 shows the balloon in its deployed or
inflated condition while in position in a tubular channel 2 that is
occluded with a thrombus 4. Hence FIG. 1 is an artery or vein 2 and
the obstruction 4 is a blood clot. However, the obstruction could
be different from a blood clot as described earlier and the tubular
channel could be different from a vein or artery. The balloon
catheter/TRAP 6 has been inserted into the vessel 2 via a guidewire
3. The balloon is inflated with balloon inflation line 5. Not
illustrated in FIG. 1 is the expandable channel of the present
invention that is illustrated in FIGS. 4, 5, 6, 7, 8 arid 9. In
FIG. 1, the balloon has a roughened surface or covering to aid with
removal of the clot 4 (or other material) from its adhesion to the
wall of the vessel 2.
[0043] Turning now to FIGS. 2A-2C, a preferred embodiment of the
Entrapping Device. FIG. 2A is a schematic illustration of the TRAP
12 device with a malecot type mechanism 6 on the distal portion
where the malecot has a roughened surface. The malecot is in its
deployed condition. The malecot mechanism could have a covering
over or within the ribs or wings, but is not illustrated in the
figure. This covering could be elastic or inelastic material.
Further, a membrane could be located within the malecot it self. In
this case, the ribs or wings 7 of the malecot would have a membrane
attached to the wings. This attachment could be the material that
the wings are made of or an added material. The material used in
construction of the malecot style TRAP 12 vary from a polymer to
metals. If metal is used, the covering or attachment between the
ribs or wings 7 would need to be a polymer such as but not limited
to polyurethanes, silicone rubber, latex, polyethylenes, PET,
MYLAR, PEBAX etc. FIG. 2B is a cross sectional view of the malecot
mechanism in its undeployed state. Longitudinal slits 8 located on
the TRAP 12 allow the ribs or wings 7 to be deployed outward. There
are at least two slits 8, but often four or six may be used. The
slits are usually in pairs (but not necessarily) in that they are
symmetrically placed around the circumference of the shaft 10. An
inner mandril or tube 9 is used to deploy or un-deploy the malecot.
The malecot could be programmed to be in the deployed condition in
its relaxed state. In this case, the inner mandril or tube 9 would
be pushed distally with respect to the shaft 10 to un-deploy the
malecot. Alternatively, the mandril or tube 9 could be pulled
proximally with respect to the shaft 10 when the malecot is
un-deployed in its relaxed condition. The inner mandril or tube 9
would be a tube when a guide wire is used to place the TRAP 12 into
position. In this case, there would be a lumen through-the entire
TRAP catheter 12 and an exit hole in the tip 11 of the device. The
guide wire and through lumen is not illustrated here. FIG. 2C is a
cross sectional illustration of the TRAP 12 with the wings 7
expanded.
[0044] Turning now to FIG. 3, is a preferred embodiment of the
Entrapping Device, the TRAP 12. Where the radially expanding
mechanism is accomplished using an expanded tubular braid on the
distal portion of the device although with all of the TRAP designs
disclosed herein, the location of the TRAP along the device may
vary proximally and distally as required for the particular
application. This braid may or may not have a covering over it
within it or under it. It is important to note that the TRAP
element may take a variety of shapes as would be required for the
particular application. FIG. 3 is a longitudinal view of the distal
portion of a support tube 14 with a braided occlusion-TRAP element
13 in its radially expanded state. This is the state where the
support tube 14 and TRAP element 13 has been inserted through or
around the occluding material that is to be removed. An inner wire
or tube 15 is used for actuation of the braided element. The
braided TRAP 13 could be expanded in its relaxed state or
conversely could be in its smaller diameter, un-deployed (not
shown) in its relaxed state. The tubular braid can be programmed to
be expanded in its relaxed state. In this case, the inner wire or
tube 15 is pushed in a distal direction to force the braided TRAP
13 into a smaller diameter and in-deployed state. The inner wire or
tube 15 may be a tube when a guide wire is used. In this case, the
inner tube 15 would have a lumen extending through the entire
device with an exit hole 16 in the distal tip 17. In the case where
the tubular braid is un-deployed and in a small diameter in its
relaxed state, the inner wire or tube 15 is pulled with respect to
the outer shaft 14 to actuate the TRAP 13 and radially expand
it.
[0045] Turning now to FIGS. 4A and 4B, there is illustrated the
tubular braid that is used in the TRAP 13 of FIG. 3 as well as the
expandable channel. PYTHON, in FIGS. 5-9. FIG. 4A illustrates the
tubular braid 18 in its smaller diameter. FIG. 4B illustrates the
tubular braid 19 in its expanded state. Shortening the tubular
braid 18 causes the expansion. This is also referred to as putting
it into compression longitudinally. Significant description of this
tubular braid is described later in the patent.
[0046] FIG. 5 is an illustration of the PYTHON expandable channel
20 as it is beginning to open and engulf the thrombus 4 inside a
vessel 2. Again FIG. 5 illustrates vascular usage for clot removal,
but the instant invention described can be used in other tubular
channels within the body for removal of visceral tissue as well as
synthetic matter. The TRAP 12 is in its deployed and radially
expanded condition distal to the material to be removed. It has
been passed through or around the material in a smaller and
un-deployed condition. The shaft 14 of the TRAP 12 is located
inside the PYTHON 20. Usually, the TRAP 12 has been put into
position and the PYTHON 21 is inserted over it in its smaller
condition. In this drawing both the PYTHON 20 and 21 as well as the
TRAP 13 are constructed using multi-stranded braid. The braid
material can be plastic, fabric, metallic, etc.
[0047] Alternatively, although not illustrated in FIG. 5, the
PYTHON 21 could be inserted into breast, liver, brain (or other
solid or solid-like tissue) for removal of matter there. This is
usually done via a percutaneous (LIS (Least Invasive Surgery) or
MIS (Minimally Invasive Surgery)) access site. This preferred
embodiment is illustrated in FIGS. 7 and 8.
[0048] In FIG. 5, the TRAP 12 illustrated is of the braided type,
but could also be any variety of TRAPS. In all figures, there may
be structures (not illustrated) in the figures that increase or
decrease the strength of the TRAP mechanism(s).
[0049] Turning now to FIG. 6 a preferred embodiment is illustrated
where the material to be removed (blood clot) 4 is fully
encapsulated inside the PYTHON expandable channel 22 and ready for
removal, dissolution or other obliteration. In FIG. 6, there is no
TRAP. This is illustrated to show that potentially the system may
be used without a TRAP as described earlier. Alternatively, the
TRAP could be removed after entrapping the matter, but prior to its
removal from the body. In this case, the TRAP 12 would be
un-deployed to its smaller diameter. This smaller diameter is near
to the diameter of the TRAP shaft 14. In its smaller diameter, it
could be withdrawn first prior to removal of the PYTHON with
entrapped matter if preferred. However, it is likely that the
PYTHON with entrapped matter would be withdrawn first, leaving the
TRAP in place should it be desired to return to the same location
again. The TRAP 12 in this instance could be used as an anchor or
tensioner so that a device (i.e., catheter) could be easily placed
over the shaft 14 of the TRAP 12. This is an exemplary embodiment
of the instant invention and could be used without an Entrapping
Device. For example it could be used anywhere a guide wire is used.
Often times the guide wire has a tendency to move after it has been
placed exactly where the interventionalist has placed it. Often the
time and effort to place the guide wire is the most critical of the
interventional procedure and assuring that this placement is
retained is very valuable. Further, a preferred embodiment of this
anchoring is the fact that the physician can also apply tension to
the guide wire shaft 14 from outside the body. This is valuable
because often disease in tubular channels within the body occur
significant distances from the entry point accomplished by the
physician. Further, the guide wire is often passed through tortuous
paths along the tubular channel. These tortuous paths are difficult
with a guide wire, but can be even more difficult when trying to
pass another device such as, but not limited to a catheter or
endoscope. By applying tension to the shaft 14 of the TRAP 12,
these tortuous paths are much less difficult to cross than without
said tension or anchoring applied. This is accomplished because the
TRAP. 12 can be made very small commensurate to conventional guide
wires.
[0050] Referring now to FIGS. 7A and 7B, the preferred embodiment
of the instant invention is illustrated for removing diseased
tissue from the breast 23. FIG. 7A illustrates a therapeutic
instrument 24 for obliteration of diseased tissue including but not
limited to cancer, fibroids, etc. The instrument is placed
percutaneously into the breast 23 (or other tissue including, but
not limited to liver, brain, pancreas, lungs, etc.). The
therapeutic instrument 24 is located in the area of the diseased
tissue and activated. This therapy or activation can be a variety
of therapies including but not limited to cryosurgery,
electrosurgery, radio frequency, thermal energy, laser surgery,
cutting, etc. The ribs or blades 25 are shown here in an expanded
condition. They are first inserted into the breast 23 (or other
tissue) in an unexpanded condition not illustrated. When they are
inserted in the unexpanded condition, they approximate the smaller
diameter of the shaft 26. This is readily accomplished in several
ways commonly known to anyone normally skilled in the art. One such
mechanism would be similar to the mechanism used to expand the TRAP
described in the instant invention where an inner member is moved
with respect to the shaft 26. In this case the ribs would move from
a smaller diameter and flattened condition to an expanded condition
as illustrated in FIGS. 7A and 7B. The expansion could also be
varied by the physician in that the more relative motion of the
inner member to the shaft 26, the greater the expansion of the ribs
or blades. This is important because the physician can then control
the amount of tissue to be treated and/or removed. The ribs or
blades 25 could be one or more in number. This rib design is
commonly used in expanding baskets for stone or other obstruction
removal.
[0051] In the case of cutting, other energies or therapies as
describe above may not be needed. In this case, the ribs or blades
may be sharp so that a twisting or turning of the device 24 would
accomplish severance of the tissue along the shape of the expanded
blades or ribs 25. If there is one blade or rib 25, the device
would be revolved 360 degrees. If two ribs or blades, 180 degrees
and so on, depending upon the number of ribs or blades 25. This
turning or revolving can be accomplished by the physician him or
her self or could be incorporated into the device itself with the
addition of a variety of different energy sources. Further, the
cutting could be aided with a variety of other energy sources
described above.
[0052] Once the tissue is treated by any of the above means, the
ribs may help in providing a scaffold for advancing the PYTHON 20.
However, the ribs or blades 25 may not be required in the situation
where the PYTHON is used as a tissue removal alone without the aid
of the therapeutic characteristic described herein. This is further
described below in regard to FIGS. 8A and 8B.
[0053] Referring now to FIG. 7B, the PYTHON 20 has been moved
forward and expanded around the treated tissue. In this case, the
expanded channel 22 of the PYTHON has entrapped the distal end of
the therapeutic device 24 including the ribs or blades 25 and the
treated tissue within. Once entrapment is assured, the PYTHON may
be aided with closing the distal end 30 utilizing a variety of
mechanisms only one of which may be a snare or drawstring 30A
attached around the distal end of the PYTHON 30. The separated
tissue within PYTHON 20 has a radially-expanding and then
radially-contracting profile which can be described as generally
ovaloid, elipsoid or spheroid such as shown in FIG. 7B. Further,
the PYTHON expandable channel may be covered or coated within the
filaments or both with an elastic or inelastic membrane. This may
be important for a number of reasons the least of which is that
upon removal of the treated tissue, it may be desirable to prevent
any particulate contamination of the diseased tissue from passing
through the tubular braid. Without this membrane protection,
diseased tissue could be left in the tract used for insertion of
the system while the system is removed from the body. Certainly,
this is critical when the diseased tissue is cancer and the only
therapy used is that of removing it from the body as opposed to
chemotherapy, cryo therapy, thermal therapy, etc. Even with these
other therapies, it may be desirous to not allow the tissue being
removed from the body to pass through the porous tubular braid.
Upon removal, the physician usually pulls the PYTHON. This pulling
puts the PYTHON expanding channel into a tensile mode which allows
the PYTHON to be reduced in diameter and in some cases back to its
original smaller diameter 21.
[0054] Turning now to FIGS. 8A and 8B, another preferred embodiment
is described. FIG. 8A illustrates a cross sectional view of the
Entrapping Device 31 inserted into the breast 23. The Entrapping
Device 31 is aimed at diseased tissue 29 located in the breast. The
location of this diseased tissue 29 can be determined by a number
of different diagnostic tools including, but not limited to MRI,
x-ray, ultrasound, palpation, mammography, etc. In FIG. 8A, the
un-deployed and smaller PYTHON expandable channel is constrained by
an outer tube 27. This outer tube 27 has before been neither
delineated nor illustrated in the figures in the aforementioned
embodiments; however, it is likely that it will be used in all of
them. Once the device 31 is in the appropriate position as is
illustrated in FIG. 8A, the PYTHON expandable channel 21 is pushed
forward. Upon pushing the PYTHON forward, it expands due to
resistance felt by the tissue in front of it or other mechanism.
The amount of expansion can be controlled by the design of the
tubular braid, surrounding tissue characteristics or in the design
of the device itself as previously described.
[0055] Turning now to FIG. 8B, the PYTHON expandable channel 22 has
entrapped the diseased tissue. This entrapment may be aided by
adding energies including, but not limited to thermal, electrical,
radio frequency, etc. or with the aid of a cutting edge on the most
distal end 32 of the PYTHON expandable channel. Further, although
not illustrated here, the distal end of the PYTHON expandable
channel 32 may have a mechanism that will close the expanded
channel prior to removal. This mechanism may include a mechanism
for severing the tissue that is not severed during the pushing
forward of the PYTHON as well.
[0056] Referring now to FIG. 9A-9C, the preferred embodiment of the
instant invention is illustrated. FIG. 9A is a cross sectional view
of an artery 2 that is diseased with an obstruction 33 which is
usually plaque that is deposited onto the inner wall of the vessel.
In FIG. 9A, the PYTHON 35 has been advanced into the artery 2 and
is just proximal to the occlusion 33. At this point, the PYTHON 21
moved forward relative to the occlusion 33 and shaft 27 and begins
to expand 20 in FIG. 9C. Again, the amount of expansion is easily
controlled as previous discussed.
[0057] As the PYTHON 20 is moved forward, it can separate the
obstruction 33 from the wall of the artery 2 because there is a
natural plane 36 that exists here between the plaque 33 and wall of
the artery 2. This separation of the plane is not illustrated in
FIG. 9. Instead, the PYTHON 20 separates the obstruction 33 from
itself and provides a larger flow lumen in the artery. FIGS. 10A
and 10B illustrate the PYTHON being used in a similar fashion as is
illustrated in FIG. 9 except that the PYTHON is used externally to
the vessel for harvesting. This is most common for vein harvesting
for the physician (vascular surgeon) to use the harvested vein as a
graft to replace diseased arteries. The most common harvested vein
is the saphenous vein. FIG. 9C illustrates the PYTHON with some of
the occlusion entrapped within the PYTHON.
[0058] These illustrations show only some potential configurations
of the instant invention. Other parametric changes of the instant
invention can occur such as location of the trapping element on the
distal portion of the device as well as the actual type of
mechanism(s) or trapping element used. Additionally, the location
of these mechanisms may vary from the proximal to the distal end
although all figures illustrate a distal location. Removal of
tumors or other diseased tissue from otherwise healthier tissue,
removal of foreign objects from channels, cavities or tissue in the
body, etc. is also disclosed.
[0059] The device of the instant invention is used for intervention
into the tubular channels (arteries, veins, biliary tract,
urological tract, gastrointestinal tract, stents, grafts, sinuses,
nasopharynx, heart, ears, etc.) or hollow cavities (stomach, gall
bladder, urinary bladder, peritoneum, etc.) of the body.
Additionally the instant invention may be used in solid or
semi-solid tissue including, but not limited to breast, liver,
brain, pancreas, lungs etc. It is particularly convenient to use in
an operating room, surgical suite, interventional suite, Emergency
Room, patient's bedside, etc. environment. One preferred embodiment
of this device is that the flexible shaft is inserted into the
tissue, tubular channel or hollow cavity of the body usually
through percutaneous access or via a surgical incision. In the case
of lumens that enter and exit the body naturally, the device may
enter through one of those entry or exit paths (i.e., rectal
opening, mouth, ear, etc.). The TRAP pulls the matter proximally
toward the PYTHON or holds the matter from moving distally in the
case when the PYTHON is moved forward. If used, the TRAP(s)
mechanism(s) is deployed (usually actuated by the physician outside
the body) so that the umbrella(s)/trap(s) configuration on the
device opens/deploys. As the TRAP is pulling the obstruction toward
the PYTHON channel, the PYTHON channel begins to open due to the
PYTHON channel being put into compression. Alternatively, the
PYTHON can be put into compression by moving it forward which
expands the PYTHON around the material. This opening of the PYTHON
channel may be aided by creating a slight flare at the most distal
end of the PYTHON channel. As the matter enters the PYTHON channel
and is enclosed within the PYTHON channel, the distal end of the
PYTHON channel may close. Other mechanisms commonly known to anyone
normally skilled in the art could be used to enhance the closure of
the distal end of the PYTHON if so desired. One such mechanism may
be a snare, which is located on the distal end of the PYTHON. In
this case the physician might pull on a string or wire that
actuates the snare and pulls the PYTHON closed. Further, other
mechanisms using electrical, magnetic, mechanical, etc. energies
could be used. This closing or compression of the PYTHON channel
can be aided by pulling on the PYTHON channel and hence putting it
into a tensile mode. The TRAP and the PYTHON channel described
herein are usually inserted into the patient in an un-deployed
fashion. It may arrive in the package in a deployed or un-deployed
state.
[0060] Once the device is in the desired position within the body,
the umbrella(s)/TRAP(s) like mechanism(s), if used, is deployed. At
this point, the user will pull the device in a retrograde fashion
into the PYTHON channel and then remove (or dissolve or otherwise
obliterate) the matter from the hollow structure. Alternatively as
previously stated, if used, the TRAP may be used to keep the matter
from moving distally while the PYTHON is moved forward. Sometimes
this removal is assisted with suction/aspiration applied to the
obstruction proximally (with the TRAP(s) deployed distally).
Alternatively, the obstruction could be engulfed inside the PYTHON
channel using aspiration/suction. Even further, the obstruction
could be engulfed inside the PYTHON channel by merely pushing the
PYTHON channel forward toward the obstruction with or without the
aid of a TRAP, irrigation, aspiration, suction etc. This forward
pushing causes the PYTHON channel to be put into compression which
in turn causes the PYTHON channel to open up to the largest
diameter. This largest diameter is available either by the design
of the PYTHON channel or by the size of the channel/lumen where the
matter is located or other tissue constraints. In the case of solid
or semi-solid tissue containing diseased tissue or other matter
that is desirable to be removed, additional instruments may be
used. As one example, the removal of a tumor from the breast may be
aided with an obliterating device (mechanical cutting, electrical,
sonic, thermal, etc.). In this case, the physician would locate the
tumor to be resected or otherwise obliterated usually with the aid
of image intensification (x-ray, palpation, mammography,
stereotactic x-ray, ultrasound imaging, endoscopes, etc.). An
elongate obliterating device may be inserted into the breast to the
tumor site where expandable `blades` would be deployed to a degree
equal to the amount of tissue to be removed. Such obliterating
blades have been used for removal of tumors in other solid or
semi-solid tissue. The blades may be mechanically cutting blades or
alternatively, other energy sources may be used to affect the
cutting of the tissue. In this case of cutting, once the tissue is
severed using the cutter, the PYTHON would be pushed forward toward
the severed tissue. The blades would help in expanding the PYTHON
around the severed tissue. In this instance it is likely that the
PYTHON would be coated with a covering that would not allow the
severed, diseased tissue from being in contact with other healthier
tissue while it is being removed. This covering may be elastic or
inelastic material. Such materials may include but are not limited
to silicone rubber, polyurethanes, PET, MYLAR, polyethylenes, etc.
This covering may be advantageous for other applications of the
PYTHON where the material being removed is desired to be fully
encapsulated within the PYTHON tubular braid channel without
allowing for any fragmented components to pass through the porous
filaments of the braid. Additionally, other techniques may be used
for removal assistance such as the use of lytic agents, laser
energy, dissolving agents, hydraulic assistance, mechanical
agitation, vibration, ultrasonic energy or any other variety of
assistance that will aid in the removal. Image intensification
(Ultrasound, fluoroscopy, MRI, etc.) may be used as well to help
with assuring the technique/removal is successful. Additionally,
direct visualization using cameras or endoscopes may be used as
well.
[0061] Possible configurations of the distal TRAP(s) mechanism(s)
are varied. One such mechanism(s) is a balloon that is inflated
distally to the obstruction. This technique has been used for
several years and has its place. However, because of the usual
smoothness that is realized with balloons, the balloon can deform
and slide past the obstruction or just not be effective enough to
remove enough of the obstruction. Hence, one preferred embodiment
of the instant invention uses a texturing on the balloon to help
with removal. This texturing can be done by actually creating a
rough surface on the outside of the balloon material that is part
of the wall of the balloon itself. Usually the balloon material is
made of elastic material such as silicone, latex, rubber, urethane,
etc. Alternatively it could be formulated with just a flexible, but
somewhat inelastic material such as PET, Mylar, Polyester, or any
number of other inelastic, but flexible materials. Further, the
material could be of some hybrid elastic/inelastic material or
compliant material. Even further, the balloon may be aided with
some other mechanical substructure that aids in the outward radial
force that is created by the balloon. All of these configurations
may or may not have a roughened texture on the exterior surface
that will aid in the removal of the obstruction. Alternatively, all
of the above mentioned configurations could have a separate or
additional material applied over the inflatable membrane which may
or may not be roughened. The roughened surface on the balloon,
malecot, covering or film within the malecot and braided devices is
easily accomplished in the manufacturing environment. One such way
is to create bubbles in a liquid slurry of the polymer prior to its
solid curing. Another might be the addition of dissolvable crystals
to the surface of the liquid polymer prior to its cure. These
dissolvable crystals could then be removed (washed off) after
curing of the polymer.
[0062] Another configuration that could be used for the TRAP is a
mechanism(s) known as a malecot. This malecot is a common
configuration used in catheters for holding them in place (in the
case of feeding tubes in the intestines or stomach). It is usually
a polymeric tube that has more than one, but usually two or more
slits symmetrically opposed. When the distal tip of the malecot is
put into compression (usually by pulling an inner wire or mandrel
or tube), the sides of the polymer are pushed outward to create a
larger diameter on the distal tip. This larger diameter is larger
than the body/shaft of the device. In the case of a malecot type
configuration (as with the inflatable mechanism(s) mentioned
above), the surface of the malecot could be roughened or a separate
membrane (attached or not) could be put over or under the malecot
so that it is roughened or strengthened. Further, a membrane that
connects the ribs or wings of a malecot is easily fabricated to
increase the surface area of the malecot ribs or wings alone.
[0063] Yet, another alternative design of the TRAP is one that has
similarities to the malecot, but uses a multi-stranded braid on the
distal end. When the braid is put into compression, the braid is
pulled together and it flares out to create a larger diameter on
the distal end. Alternatively, either the braid or the malecot can
have a permanent set put into in so that it is normally open with
the larger diameter. In this case, when it is put into tension
(usually from some inner (or outer) core wire or mandrel), it
collapses down to the diameter of the shaft of the device.
[0064] Alternatively, too much abrasive action on the surface
of-the mechanism(s) may be deleterious to the patient as well. In
the case of the braided configuration, some smoothener may be
required so that-just the appropriate amount of friction is
realized for effective obstruction removal. Further, the realized
rigidity of any of the type of mechanism(s)s must be optimized for
this removal in the particular application.
[0065] The PYTHON channel can also be fabricated from several
materials and configurations. One preferred configuration is
similar to one of the TRAP designs; that being a multi-stranded
braided device. The strands can be made of any material that would
be useful for a particular application (polymers like polyester,
nylon, Mylar, etc.) or, metal (stainless steel, nickel titanium
allow (Nitinol), platinum, etc.). Certainly, the materials of the
instant invention are not constrained to those materials listed
Additionally, the PYTHON channel may be coated or encased in an
elastomeric or other covering. Further, the PYTHON channel may be
fabricated of a material that will enlarge due to different forces
than that of the braid mentioned previously. One other such force
derived mechanism could be a material that swells/enlarges when put
into a moist environment. Another such forced derived mechanism is
one that swells/enlarges when thermal energy is applied such as Two
Way Shaped Memory Alloy (TWSMA) such as a Nickel-Titanium alloy.
Yet, another may be one that occurs from an electrical, magnetic or
other mechanical configuration/design/force.
[0066] The Tubular Braid Elements
[0067] The TRAP apparatus includes an elongate tube; an elongate
mandril inside the tube and an expandable tubular braid. The
elongate mandril extends from the proximal end of the device to the
distal end. The elongate tube usually extends from close to the
proximal end of the device to close to the distal end. The distal
end of the tubular braid is bonded to the distal end of the inner
elongate mandril. The mandril may extend beyond the tubular braid.
The proximal end of the tubular braid is bonded to the distal end
of the elongate tube.
[0068] The braid may be open, but may be laminated or covered with
a coating of elastic, generally inelastic, plastic or plastically
deformable material, such as silicone rubber, latex, polyethylene,
thermoplastic elastomers (such as C-Flex, commercially available
from Consolidated Polymer Technology), polyurethane and the like.
The assembly of tube, mandril and braid is introduced
percutaneously in its radially compressed state. In this state, the
outside diameter of the braid is close to the outside diameter of
the elongate tube. This diameter is in the range of 10 to 500 mils,
and usually 25 to 250 mils (i.e., thousandth of an inch). After
insertion, moving the mandril proximally with respect to the tube
expands the tubular braid.
[0069] The tubular braid is preferably formed as a mesh of
individual non-elastic filaments (called "yarns" in the braiding
industry). However, it can have some elastic filaments interwoven
to create certain characteristics. The non-elastic yarns can be
materials such as polyester, PET, polypropylene, polyamide fiber
(Kevlar, DuPont), composite filament wound polymer, extruded
polymer tubing (such as Nylon II or Ultem, commercially available
from General Electric), stainless steel, Nickel Titanium (Nitinol),
or the like so that axial shortening causes radial expansion of the
braid. These materials have sufficient strength so that the TRAP
element will retain its expanded condition in the lumen of the body
while removing the matter therefrom. Further, all expandable
mechanisms described heretofore, can be manufactured using shape
memory materials so that they are self expanding or even expandable
when certain temperatures or thermal energies are delivered to the
mechanisms. Such material characteristics can be accomplished with
different programming methods such as, but not limited to Two Way
Shape Memory (TWSM) alloys.
[0070] The braid may be of conventional construction, comprising
round filaments, flat or ribbon filaments, square filaments, or the
like. Non-round filaments may be advantageous to decrease the axial
force required for expansion to create a preferred surface area
configuration or to decrease the wall thickness of the tubular
braid. The filament width or diameter will typically be from about
0.5 to 50 mils, usually being from about 5 to 20 mils. Suitable
braids are commercially available from a variety of commercial
suppliers.
[0071] The tubular braids are typically formed by a "Maypole" dance
of yarn carriers. The braid consists of two systems of yarns
alternately passing over and under each other causing a zigzag
pattern on the surface. One system of yarns moves helically
clockwise with respect to the fabric axis while the other moves
helically counter-clockwise. The resulting fabric is a tubular
braid. Common applications of tubular braids are lacings,
electrical cable covers (i.e., insulation and shielding), "Chinese
hand-cuffs" and reinforcements for composites. To form a balanced,
torque-free fabric (tubular braid), the structure must contain the
same number of yarns in each helical direction. The tubular braid
may also be pressed flat to form a double thickness fabric strip.
The braid weave used in the tubular braid of the present invention
will preferably be of the construction known as "two dimensional,
tubular, diamond braid" that has a 1/1 intersection pattern of the
yarns which is referred to as the "intersection repeat."
Alternatively, a Regular braid with a 2/2 intersection repeat and a
Hercules braid with an intersection repeat of 3/3 may be used. In
all instances, the helix angle (that being the angle between the
axis of the tubular braid and the yarn) will increase as the braid
is expanded. Even further, Longitudinal Lay-Ins can be added within
the braid yarns and parallel to the axis to aid with stability,
improve tensile and compressive properties and modulus of the
fabric. When these longitudinal "Lay-In" yarns are elastic in
nature, the tubular braid is known as an elastic braid. When the
longitudinal yarns are stiff, the fabric is called a rigid braid.
Biaxially braided fabrics such as those of the present invention
are not dimensionally stable. This is why the braid can be placed
into an expanded state from a relaxed state (in the case of putting
it into the compressive mode). Alternatively this could be a
decreased/reduced (braid diameter decreases) state when put into
tension from the relaxed state. When put into tension (or
compression for that matter) the braid eventually reaches a state
wherein the diameter will decrease no more. This is called the
"Jammed State." On a stress strain curve, this corresponds to
increase modulus. Much of the engineering analyses concerning
braids are calculated using the "Jammed State" of the
structure/braid. These calculations help one skilled in the art to
design a braid with particular desired characteristics. Further,
material characteristics are tensile strength, stiffness and
Young's modulus. In most instances, varying the material
characteristics will vary the force with which the expanded
condition of the tubular can exert radially. Even further, the
friction between the individual yarns has an effect on the force
required to compress and un-compress the tubular braid. For the
present invention, friction should be relatively low for a chosen
yarn so that the user will have little trouble deploying the
engaging element. This is particularly important when the engaging
element is located a significant distance from the user. Such is
the case when the percutaneous entry is the groin (Femoral Artery
for vascular interventions) and the point of engaging the engaging
element is some distance away (i.e., the Carotid Artery in the
neck). Similarly, this is true for long distances that are not
vascular or percutaneous applications.
[0072] Other Comments
[0073] An important consideration of the invention described herein
is that the support wire with its expanding element can be
fabricated with a very small diameter. This is important because it
allows an optimally large annular space between the wire and the
inside of the PYTHON for maximum obstruction removal. Previous
engaging elements have been used that use a balloon for the
engaging element. This balloon design requires a larger shaft
diameter than that of the present invention. Hence, in these
previous devices the annular space is not maximized as in the
present invention. The term wire is used to refer to the support
portion of the removal TRAP device. The material of the wire need
not necessarily be metal. Further, it may be desirable to use a
`double` engaging element (i.e., two braided or malecot expanding
elements separated a distance appropriate to entrap the occlusion)
in the case for example where the occlusion is desired to be
trapped in the vessel. The term wire is used herein to refer to a
dual element device having a shell component and a core or mandril
component which are longitudinally moveable relative to one another
so as to be able to place the braided TRAP element into its small
diameter insertion state and its large diameter occlusion removal
state.
[0074] Additionally, other instruments/mechanisms may be used to
help orient the obstruction or tissue into the PYTHON channel. This
may be of particular importance when the PYTHON is used in a hollow
cavity such as the stomach or peritoneal cavity. In such an
instance, a variety of devices (or no devices) may be used to aid
with arranging the obstruction, tissue, organ, etc. into the
PYTHON.
[0075] Device Testing
[0076] Prototypes of the PYTHON were fabricated from the materials
disclosed heretofore and of the dimensions commensurate with this
disclosure. Congealed matter such as blood and gels were installed
in graft material (Expanded PTFE) and other polymeric tubular
channels (with and without TRAP mechanisms). The PYTHON easily
removed more than 95% of the enclosed matter from the graft.
Further, metallic tubular braid severed semi-solid material by
forcing in into the semi-solid material. This severing of material
was accomplished even without the aid of other energies disclosed
heretofore.
[0077] An exemplary device has the following characteristics:
[0078] Working Length
[0079] 10-500 cm
[0080] Working Diameter
[0081] The wire of the TRAP has an outer diameter that ranges from
0.006" to 0.150", but can extend to smaller and larger sizes as
technology and procedures require. The TRAP of the instant
invention would be small in its un-deployed state (similar to that
of the wire mentioned above), but would be expandable to diameters
of 10 mils to 500 mils or even larger. The PYTHON channel will
usually have two diameters as well, a smaller diameter for
insertion into the body which would in the range of 20 to 100 mils
or even larger.
[0082] Physical Configuration
[0083] The device of the instant invention may have conventional
lubricious coatings to enhance nitroduction into the target body
lumen, e.g., hyaluronic or other equivalent coatings. Further the
technician may apply a lubricious coating just before surgery. As
an advantage of the instant invention, the device will be less
difficult to feed it to the desired location in the body due to its
decreased size. Another advantage of the instant invention would be
the ease with which matter can be entrapped for removal or
obliteration. This decreased difficulty will decrease cost due to
time in the Operating Room (Operating Room costs are estimated in
excess of $90 per minute in the U.S.). Additionally, there will be
realized a decrease in difficulty for removal of the matter and
will aid in patient care/recovery and the potential in deleterious
effects due to the inability to remove the matter (part or all)
from the patient.
[0084] An exemplary device having an umbrella(s)/TRAP(s)
mechanism(s) located on its distal tip is illustrated in figures.
This TRAP(s) mechanism(s) may be at the tip or somewhere else in
the distal portion of the device or even in the middle of the
device. Additionally, this mechanism(s) may be any of a number of
mechanisms that will help aid in removing the matter.
[0085] The pushability of the PYTHON channel or sheath may be
limiting and advancement may be problematic. If this should occur,
an outer sleeve may be added to the PYTHON channel to aid with
positioning of the device in the preferred location (usually
adjacent to the obstruction). Once the PYTHON channel is the
position, the sleeve could be removed so that additional push or
compression will allow the PYTHON channel to expand, open, and
hence entrap the obstruction. Alternatively or in addition to the
outer containing sleeve of the PYTHON, an inner mandrel wire might
be used to pull the PYTHON into the desired position in the
body.
[0086] Although the foregoing invention has been described in some
detail by way of illustration and example, for purposes of clarity
of understanding, it will be obvious that certain changes and
modifications may be practiced within the scope of the appended
claims.
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