U.S. patent application number 11/924369 was filed with the patent office on 2008-10-30 for intracorporeal grasping device.
This patent application is currently assigned to Chestnut Medical Technologies, Inc.. Invention is credited to Aaron Lee Berez, Bart Bojanowski, Adrian Garcia, Alec Piplani, Quang Q. Tran, Ting Tina Ye.
Application Number | 20080269774 11/924369 |
Document ID | / |
Family ID | 39887887 |
Filed Date | 2008-10-30 |
United States Patent
Application |
20080269774 |
Kind Code |
A1 |
Garcia; Adrian ; et
al. |
October 30, 2008 |
Intracorporeal Grasping Device
Abstract
An intracorporeal grasping device includes a tubular member for
entering a lumen of a human body and the tube member having a
distal end portion. An elongated core member is disposed with the
interior cavity of the tubular member for rotational or slidably
movement within the tubular member and the elongated core member
having a proximal end portion and a distal end portion. The
elongated core member comprises a uniform diameter tube having some
flexibility at the proximal end portion and greater flexibility
while along a longitudinal axis in a direction towards the distal
end portion; and a grasping configuration is provided for capturing
an object (e.g., clot or debris) therein and the assembly may have
a proximal end secured to the distal end of the elongated core
member. The configuration has an expanded and contracted
configuration, and distal sections configured to grasp an object.
The grasping configuration may be formed by at least one movable
jaw attached to the distal end portion of the elongated core member
and a length portion of the distal end portion of the tube member.
The grasping configuration may include unitarily formed plurality
of movable jaws attached to the distal end portion of the elongated
core member. Further, the grasping configuration may be formed by a
plurality of loop members attached to the distal end portion of the
elongated core member. Further, the grasping configuration may be
formed by at least one spiral member having a distal tip for
penetrating an object to be removed from a human body lumen. The
device has the spiral member provided at the distal end portion of
the elongated core member. The grasping configuration can be formed
by at least one web member for retaining an object to be removed
from a human body lumen, the web member being provided at the
distal end portion of the elongated core member.
Inventors: |
Garcia; Adrian; (Los Gatos,
CA) ; Ye; Ting Tina; (San Jose, CA) ; Tran;
Quang Q.; (Redwood City, CA) ; Bojanowski; Bart;
(San Jose, CA) ; Piplani; Alec; (San Jose, CA)
; Berez; Aaron Lee; (Menlo Park, CA) |
Correspondence
Address: |
BANNER & WITCOFF, LTD.
1100 13th STREET, N.W., SUITE 1200
WASHINGTON
DC
20005-4051
US
|
Assignee: |
Chestnut Medical Technologies,
Inc.
Menlo Park
CA
|
Family ID: |
39887887 |
Appl. No.: |
11/924369 |
Filed: |
October 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60854439 |
Oct 26, 2006 |
|
|
|
Current U.S.
Class: |
606/127 |
Current CPC
Class: |
A61B 2017/22034
20130101; A61B 2017/2212 20130101; A61B 17/221 20130101; A61B
2017/2215 20130101 |
Class at
Publication: |
606/127 |
International
Class: |
A61B 17/221 20060101
A61B017/221 |
Claims
1. An intracorporeal grasping device having a longitudinal axis,
comprising: an elongated core member having a proximal end portion
and a distal end portion, the elongated core member comprising a
generally uniform diameter tube having variable flexibility along a
length from the proximal end portion to the distal end portion; and
a grasping assembly attached to the distal end portion of the
elongated core member.
2. The intracorporeal grasping device of claim 1, wherein the
distal portion of the core member is at least in part 10%-25% more
flexible than the proximal portion of the core member.
3. The intracorporeal grasping device of claim 1, wherein the
wherein the distal portion of the core member is at least in part
35%-50% more flexible than the proximal portion of the core
member.
4. The intracorporeal grasping device of claim 1, wherein the tube
further comprises a series of spaced circumferential slots at the
distal end portion to provide variability flexibility of the
tube.
5. The intracorporeal grasping device of claim 1, wherein the
wherein an intermediate portion of the core member is defined
between the distal end portion and the proximal end portion, the
intermediate portion having greater flexibility than the proximal
end portion of the core member, and the intermediate portion having
less flexibility than the distal end portion of the core
member.
6. The intracorporeal grasping device of claim 5, wherein the tube
comprises a series of circumferential slots providing the distal
end portion with greater flexibility than the intermediate
portion.
7. The intracorporeal grasping device of claim 5, wherein the tube
further comprises a series of circumferential slots, wherein a
density of the slots is higher at the distal end portion than a
density of slots at the proximal end portion.
8. The intracorporeal grasping device of claim 7, wherein there is
a continuous transition along the length of the tube from higher
density of slots to lower the density of slots.
9. The intracorporeal grasping device of claim 1, further
comprising a uniform diameter core centered within the tube and
spanning the length of the tube.
10. The intracorporeal grasping device of claim 9, wherein at least
the ends of the core are radially attached to the tube.
11. The intracorporeal grasping device of claim 10, wherein the
core is radially attached to the tube by at least one of soldering,
welding or brazing.
12. An intracorporeal grasping device having a longitudinal axis,
comprising: a movable elongated core having a proximal end and a
distal end, the elongated core comprising a plurality of flexion
regions having different flexions along a length from the proximal
end to the distal end portion; and a grasping assembly attached to
the distal end of the elongated core.
13. The intracorporeal grasping device of claim 12, wherein at
least one flexion region of the core member is 10%-25% more
flexible than another flexion region the core member.
14. The intracorporeal grasping device of claim 12, wherein the
wherein at least one flexion region of the core member is 35%-50%
more flexible than another flexion region. of the core member.
15. The intracorporeal grasping device of claim 12, wherein the
flexion regions include plurality circumferential slots of
different densities.
16. An intracorporeal grasping device, comprising: a tubular member
for entering a lumen of a human body and the tubular member having
a distal end portion; an elongated core member being disposed with
the tubular member and the elongated core member having a proximal
end portion and a distal end portion; and a grasping configuration
for capturing an object therein, in which the grasping
configuration is formed by at least one spiral member having a
distal tip for penetrating an object to be removed from a human
body lumen, the spiral member being provided at the distal end
portion of the elongated core member.
17. The grasping device according to claim 16, wherein the spiral
member is configured to rotate by an axis to penetrate the object
to be removed.
18. The grasping device according to claim 16, wherein the grasping
configuration includes a moveable jaw type member.
19. The grasping device according to claim 18, wherein the grasping
configuration is formed with tubing having at least one perforation
for releasing a fluid from within the tubing.
20. The grasping device according to claim 16, wherein the
elongated core member has variable flexibility along a length from
the proximal end portion to the distal end portion.
21. The grasping device according to claim 16, wherein the tube
further comprises a series of spaced circumferential slots at the
distal end portion to provide variability flexibility of the
tube.
22. The grasping device according to claim 16, wherein the wherein
an intermediate portion of the core member is defined between the
distal end portion and the proximal end portion, the intermediate
portion having greater flexibility than the proximal end portion of
the core member, and the intermediate portion having less
flexibility than the distal end portion of the core member.
23. An intracorporeal grasping device, comprising: a tubular member
for entering a lumen of a human body and the tubular member having
a distal end portion; an elongated core member being disposed with
the tubular member and the elongated core member having a proximal
end portion and a distal end portion; and a grasping configuration
for capturing an object therein, in which the grasping
configuration is formed by at least one web member retaining an
object to be removed from a human body lumen, the web member being
provided at the distal end portion of the elongated core
member.
24. The grasping device according to claim 23, wherein the grasping
configuration includes a moveable jaw type member attached to the
web member.
25. The grasping device according to claim 24, wherein the grasping
configuration is formed with tubing having a wall with at least one
perforation for releasing a fluid from within the tubing.
26. The grasping device according to claim 25, wherein the jaws
includes an engaging surface and an opposing surface, the engaging
surface including a plurality of engaging elements provided along a
longitudinal length thereof.
27. The grasping device according to claim 26, wherein the engaging
elements are formed as ribs inwardly extending thereof.
28. The grasping device according to claim 23, wherein the
elongated core member has variable flexibility along a length from
the proximal end portion to the distal end portion.
29. An intracorporeal grasping device, comprising: a tubular member
for entering a lumen of a human body and the tubular member having
a distal end portion; an elongated core member being disposed with
the tubular member and the elongated core member having a proximal
end portion and a distal end portion; and a grasping configuration
for capturing an object therein, in which the grasping
configuration is formed by at least one spiral member having a
distal tip for penetrating an object to be removed from a human
body lumen, the spiral member being provided at the distal end
portion of the elongated core member.
30. The grasping device according to claim 29, wherein the spiral
member is configured to rotate by an axis to penetrate the object
to be removed.
31. The grasping device according to claim 29, wherein the grasping
configuration includes a moveable jaw type member.
32. The grasping device according to claim 29, wherein the grasping
configuration is formed with tubing having at least one perforation
for releasing a fluid from within the tubing.
33. The grasping device according to claim 29, wherein the
elongated core member has variable flexibility along a length from
the proximal end portion to the distal end portion.
34. The grasping device according to claim 29, wherein the tube
further comprises a series of spaced circumferential slots at the
distal end portion to provide variability flexibility of the
tube.
35. The grasping device according to claim 29, wherein the wherein
an intermediate portion of the core member is defined between the
distal end portion and the proximal end portion, the intermediate
portion having greater flexibility than the proximal end portion of
the core member, and the intermediate portion having less
flexibility than the distal end portion of the core member.
36. An intracorporeal grasping device, comprising: a tubular member
for entering a lumen of a human body and the tubular member having
a distal end portion; an elongated core member being disposed with
the tubular member and the elongated core member having a proximal
end portion and a distal end portion; and a grasping configuration
for capturing an object therein, in which the grasping
configuration is formed by at least one web member retaining an
object to be removed from a human body lumen, the web member being
provided at the distal end portion of the elongated core
member.
37. The grasping device according to claim 36, wherein the grasping
configuration includes a moveable jaw type member attached to the
web member.
38. The grasping device according to claim 37, wherein the grasping
configuration is formed with tubing having a wall with at least one
perforation for releasing a fluid from within the tubing.
39. The grasping device according to claim 38, wherein the jaws
includes an engaging surface and an opposing surface, the engaging
surface including a plurality of engaging elements provided along a
longitudinal length thereof.
40. The grasping device according to claim 39, wherein the engaging
elements are formed as ribs inwardly extending thereof.
41. The grasping device according to claim 36, wherein the
elongated core member has variable flexibility along a length from
the proximal end portion to the distal end portion.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority to
Provisional Application 60/854,439 filed in the U.S. Patent and
Trademark Office on Oct. 26, 2006. The content of the noted
application is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention pertains to an intracorporeal device and
method for grasping objects within a patient's body and withdrawing
the grasped objects from the patient's body. More specifically, the
intracorporeal device is a grasping device having an internal shaft
for removing an object, such as from a patient's vasculature.
BACKGROUND OF THE INVENTION
[0003] Developments in medical technology and associated treatments
have been focused on clearing or removing thromboembolisms or
"blood clots" from the cervical and cerebral vasculature in order
to treat thromboembolic stroke victims. Thromboembolic stroke is a
life threatening condition that consists of arrested blood flow to
a region of the brain due to a thromboembolism blocking a blood
vessel feeding that region. Such thrombi often originate in the
left heart chambers, break free into the aorta and flow downstream
into the cervical neck arteries e.g. carotid arteries, and then
ultimately lodge into a narrowed vessel somewhere down the
narrowing vascular tree of the cerebral arteries associated with
the brain in the head. Once lodged, the thrombus occludes flow
along the vessel downstream of the blockage, thus arresting blood
flow to the downstream blood vessel and causing the stroke.
[0004] Several grasping device assemblies and methods have been
disclosed specifically for removing thrombi from the cervical and
cerebral vessels in order to treat thromboembolic stroke. However,
many of these devices have grasping assemblies that are not well
adopted for delivery to distal regions of the cerebral vessels
where many thromboembolisms are known to cause a debilitating
stroke.
[0005] U.S. Pat. No. 6,679,893 describes a grasping device for
removing thrombi from the cervical and cerebral vessels in order to
treat thromboembolic stroke. This patent describes several grasping
assemblies that may be utilized in its device. However, it is
desired to have more flexibility in the selection of grasping
assemblies depending on the type and location of the thrombi.
[0006] When retrieving a neurovascular clot or foreign body, a
device having a distal grasping end with greater flexibility is
desired. It is also desired to have a distal grasping end that is
easily manufactured based on the desired flexibility.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention pertains to an intracorporeal device and
method for grasping objects within lumen of a human body and
withdrawing the grasped objects from the human body.
[0008] In one aspect, an intracorporeal grasping device includes an
elongated core having a proximal end portion and a distal end
portion. The elongated core includes a tube having a variable
flexibility along a length from the proximal end portion to the
distal end portion. A grasping configuration is disposed to the
distal end portion of the elongated core member for grasping an
object from a human body.
[0009] In another aspect, an intracorporeal grasping device
includes a movable elongated core having a proximal end and a
distal end. The elongated core includes a plurality of flexion
regions having different flexions along a length from the proximal
end to the distal end portion. A grasping configuration is provided
at the distal end of the elongated core for retaining and capturing
objects.
[0010] In yet another aspect, an intracorporeal grasping device
includes a tubular member for entering a lumen of a human body and
the tube member having a distal end portion. An elongated core
member is disposed with the interior cavity of the tubular member
for rotational or slidably movement within the tubular member and
the elongated core member having a proximal end portion and a
distal end portion. A grasping configuration is provided for
capturing an object (e.g., clot or debris) therein in which the
grasping configuration is formed by at least one movable jaw
attached to the distal end portion of the elongated core member and
a length portion of the distal end portion of the tube member.
[0011] In another aspect, an intracorporeal grasping device
includes a tubular member for entering a lumen of a human body and
the tubular member having a distal end portion. An elongated core
member is disposed with the tubular member and the elongated core
member has a proximal end portion and a distal end portion. A
grasping configuration captures an object in which the grasping
configuration includes unitarily formed plurality of movable jaws
attached to the distal end portion of the elongated core
member.
[0012] In another aspect, an intracorporeal grasping device
includes a tubular member for entering a lumen of a human body and
the tubular member has a distal end portion. An elongated core
member being disposed with the tubular member and the elongated
core member has a proximal end portion and a distal end portion.
The device includes a grasping configuration for capturing an
object therein, in which the grasping configuration is formed by a
plurality of loop members attached to the distal end portion of the
elongated core member.
[0013] In one aspect, an intracorporeal grasping device includes a
tubular member for entering a lumen of a human body and the tubular
member having a distal end portion. An elongated core member being
disposed with the tubular member and the elongated core member
having a proximal end portion and a distal end portion. A grasping
configuration is provided for capturing an object therein, in which
the grasping configuration is formed by at least one spiral member
having a distal tip for penetrating an object to be removed from a
human body lumen. In the device has the spiral member provided at
the distal end portion of the elongated core member.
[0014] An intracorporeal grasping device includes a tubular member
for entering a lumen of a human body and the tubular member having
a distal end portion. An elongated core member is disposed with the
tubular member and the elongated core member has a proximal end
portion and a distal end portion. A grasping configuration captures
an object therein, in which the grasping configuration is formed by
at least one web member for retaining an object to be removed from
a human body lumen, the web member being provided at the distal end
portion of the elongated core member.
[0015] In various other aspects, at least one of the jaws may
include an engaging surface and an opposing surface, the engaging
surface including a plurality of engaging elements provided along a
longitudinal length thereof and the engaging elements. In another
aspect, wherein the engaging elements are provided as ribs inwardly
extending for capturing an object. In another aspect, at least one
of the jaws is perforated at the location of the ribs.
[0016] In another aspect, at least one of the jaws has a distal end
with an aperture and the jaw includes a lumen along a length
enabling a fluid communications pathway to a distal end of the
jaw.
[0017] The above and other aspects, features and advantages of the
present invention will be readily apparent and fully understood
from the following detailed description illustrative embodiments in
conjunction with the accompanying drawings, which are included by
way of example, and not by way of limitation with regard to the
claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of schematic representation of
an intracorporeal grasping system according to the teaching of
present invention.
[0019] FIG. 2 is an elevational view of the grasping device shown
in FIG. 1.
[0020] FIG. 3 is an enlarged section view of an elongated core
member taken along the line 3-3 of FIG. 2.
[0021] FIG. 4 shows a side elevational view, partially in section,
of the grasping device shown in FIG. 2 in a closed configuration
within the inner lumen of the delivery catheter.
[0022] FIG. 5 depicts the grasping device disposed within the
delivery catheter with the grasping assembly of the device
extending out the port in the distal end of a delivery catheter
into a body lumen adjacent to a thrombus and being in an expanded
configuration therein.
[0023] FIG. 6 illustrates an elevational view of the grasping
device within a delivery catheter having the grasping assembly on
the distal end of the device being in a partially contracted
configuration about a thromboembolism.
[0024] FIG. 7 is a schematic illustration of the grasping system
shown in FIG. 1 operatively disposed in a left side internal
carotid artery location in position to perform an exemplary
thrombectomy procedure within the middle cerebral artery.
[0025] FIGS. 8A-8C illustrate an alternative embodiment of a
grasping system according to the teaching of the present
invention.
[0026] FIGS. 9A-9C illustrate an alternative embodiment of a
grasping system according to the teaching of the present
invention.
[0027] FIGS. 10A-10F illustrate an alternative embodiments of
grasping device components according to the teaching of the present
invention.
[0028] FIG. 11 illustrates an alternative embodiment of a grasping
device component according to the teaching of the present
invention.
[0029] FIGS. 12A-12E illustrate alternative embodiments of grasping
device components according to the teaching of the present
invention.
[0030] FIGS. 13A-13F illustrate another embodiment of a grasping
system according to the teaching of the present invention.
[0031] FIGS. 14A-14D illustrate an alternative embodiment of a
grasping system according to the teaching of the present
invention.
[0032] FIGS. 15A-15B illustrate an alternative embodiment of a
grasping system according to the teaching of the present
invention.
[0033] FIGS. 16A-16C illustrate an alternative embodiment of a
grasping device according to the teaching of the present
invention.
[0034] FIGS. 17A-17D illustrate an alternative embodiment of a
grasping device according to the teaching of the present invention.
FIG. 17A is an elevational view of the grasping device; FIG. 17B is
a front axial view of the grasping device; and FIG. 17C is a
sectional view taken along line 17C-17C in FIG. 17A.
DETAILED DESCRIPTION
[0035] The following embodiments and aspects thereof are described
and illustrated in systems and methods which are meant to exemplary
and illustrative and non-limiting in scope.
[0036] FIGS. 1-6 schematically illustrate an intracorporeal
grasping system 10. In one embodiment by way of example, the
grasping system 10 includes a grasping device 11, a delivery
catheter 12 and a guide catheter 13. In some instances only the
grasping device 11 and either the delivery catheter 12 or the guide
catheter 13 are used, but not both.
[0037] As shown in FIG. 1 and in greater detail in FIG. 2, the
grasping device 11 includes an elongated core member 14 having a
proximal end 15 and a distal end 16. The grasping device 11 further
includes a grasping configuration 17 attached to the distal end of
the core member 14. The core member 14 can have a number of
arrangements. In one embodiment by way of example, core member 14
is provided with variable bending flexibility along a predetermined
length. Hence, this configuration of the core member 14 allows for
improved transluminal manipulation of the grasping device 11 in a
human body. In one construction, core member 14 is flexible in
nature so as to traverse the potentially tortuous and/or angled
geometry of the cervical vascular tree.
[0038] With reference to FIG. 3, elongated core member 14 includes
a cylindrical tube 25 having a generally uniform diameter. A
generally solid cylindrical core wire 26 is concentrically disposed
within the cylindrical tube 25. A circumferential gap between the
tube 25 and wire 26 may be filled with solder, for example. The
solid cylindrical core wire prevents uniform cylindrical tube 25
from excessive longitudinal elongating along its length.
[0039] In one embodiment by way of example, the flexibility of the
uniform cylindrical tube 25 can be provided by a plurality of
spaced circumferential slots 70 extending through the wall
thickness (See FIG. 2). For ease of explanation, the term "density"
with reference to cuts or slots of the core member, generally
refers to the number of slots or cuts per a unit of length or area.
Non limiting examples of a unit of length are a centimeter, an inch
or smaller linear units. Likewise, a unit of area may be square
inches or square centimeters and the like.
[0040] In accordance with an embodiment of the grasping device, the
amount or magnitude of flexibility is proportional to the number of
slots per unit of measure. For example, a high density of slots
provides higher flexibility, than a lower density of slots. By
changing the density and/or pattern of the circumferential slots,
the flexibility of the elongated core member 14 can be changed.
[0041] Core member 14 may have a multi-flexion configuration that
has separate regions of different flexions that each correspond to
the flexibility, or lack thereof, for improved transluminal
manipulation. This multi-flexion regional configuration provides
adaptability for a practitioner to reduce steps for accessing or
grasping an object or customize the access in body lumens to
increase patient comfort. In one exemplary construction, the core
member 14 may have three flex regions to accommodate to
transluminal access. A first flexion region 29 may extend from the
distal end 16 to a first intermediate position 29a along the length
of the elongated core member 14. The first flexion region 29 is
substantially flexible for improved comfort, for example. An
adjacent second flexion region 28 may extend to another
intermediate position 28a away from first intermediate position 29a
along the length of the elongated core member 14. The second
flexion region 28 may be less flexible than a first flex region 29
so as to allow the elongated core member 14 to traverse the
vascular geometry in an improved fashion. A third flex region 27
may be provided adjacent to the second flexion region 28. The third
flexion region 27 may be less flexible than the second flexion
region and the first flexion region.
[0042] Referencing FIG. 2, in one construction, the uniform
diameter tube 25 has a distal section 29, middle section 28 and
proximal section 27 generally corresponding to the multi-flexion
configuration in which each section has a different flexibility
with respect to each other. For example, the distal section 29 may
have a high flexibility, the middle section 28 may have a medium
flexibility, and the proximal section 27 has a low or minimal
flexibility. Hence, distal section 29 has the greatest flexibility
of the sections 28, 27. These sections are all part of the same
uniform cylindrical tube 25 having three distinct stiffness or
flexion sections. In one embodiment, the distal section 29 of the
core member 14 can be at least in part 10%-25% more flexible than
the proximal section 27 of the core member 14. The middle section
28 can be at least in part 5%-20% more flexible than the proximal
section 27. The distal section 29 can be 5%-20% more flexible than
the middle section 28. In alternative embodiment, the distal
section 29 of the core member can be at least in part 35%-50% more
flexible than the proximal section 27 of the core member. The
middle section 28 can be at least in part 30%-45% more flexible
than the proximal section 27. The distal section 29 can be 30%-45%
more flexible than the middle section 28. Nevertheless, other
flexibility relative values are possible.
[0043] Any suitable number of stiffness/flexible sections could be
used on the core member 14. In a specific non-limiting example, the
dimensions of the first flexion region maybe 3.0 cm from the distal
end; second flexion region may have a length of 5.0 to 15.0 cm; and
the third flexion region may have a length of 20.0 to 40.0 cm.
Nevertheless, the length of the regions maybe configured as desired
by the practitioner. In an alternative embodiment, the density of
the slots can be increased uniformly for a continuous transition
from proximal low flexibility to distal high flexibility for the
core member 14.
[0044] The solid cylindrical core wire 26 spans the length of the
uniform cylindrical tube 25 and is affixed to the tube by any
suitable method by soldering e.g. with silver or gold solder.
brazing, welding, adhesives, mechanical connections or other
suitable techniques. The solid cylindrical core wire 26 is
preferably attached to the tube at least at both ends of the core
wire.
[0045] The circumferential slots or cuts can be made by any
suitable manufacturing technique, such as, for example, computer
numerically controlled (CNC) microsawing, EDM wire cutting, or
laser cutting.
[0046] The uniform cylindrical tube 25 is generally formed of a
high strength material such as stainless steel, superelastic
nickel-titanium alloy, cobalt-chromium-molybdenum alloys such as
MP35N and Elgiloy or other material having suitable strength,
stiffness, and other attributes for allowing percutaneous
transluminal manipulation of the grasping device 11 as described
herein. Suitable materials include but are not limited to 304SS or
NITINOL.
[0047] As used herein, the term "superelastic shape memory
material" refers to a class of metal alloys that have a
stress-induced phase change from austenite to martensite and upon
stress release, the material springs back to this original phase
and shape. The material structure of a superelastic shape memory
material regarding austenite and martensite is well-known to one of
ordinary skill in the metallurgy art. A NiTi material or NiTi alloy
may be used as an alloy material for the flex control member 21. As
used herein, a NiTi superelastic shape memory material refers to an
alloy that is an intermetallic compound of nickel and titanium
having nearly equal mixtures as measured by weight. One composition
of a NiTi superelastic shape memory material generally has a
greater percentage of nickel by weight than titanium, such as
51%-56% of nickel, and preferably 54-55% nickel. The specific
percentages of nickel and titanium can be adjusted by one of
ordinary skill in the art. It should be recognized that additional
metals, such as copper, iron, chromium, and cobalt, can be added to
fine tune various properties of a NiTi superelastic shape set
material.
[0048] One embodiment, core member 14 is preferably constructed
from a superelastic shape set material commonly called NITINOL.RTM.
depending upon the alloy composition. NITINOL.RTM. is a brand name
which refers to Nickel Titanium Naval Ordinance Laboratory, a
commercially available family of nickel titanium alloys. Among the
suppliers, NITINOL.RTM. material can be obtained from NDC of
Fremont, Calif. Nevertheless, there are numerous other suppliers of
NiTi materials and NiTi superelastic shape set materials.
[0049] The outer diameter of cylindrical tube 25 should be selected
for slidable advancement within the inner lumen 36 of the delivery
catheter (See FIGS. 1 and 4). Generally, outer diameter of
cylindrical tube 25 is about 0.015 inch to about 0.040 inch, and
preferably about 0.010 to about 0.038 inch. An outer lubricous
coating (not shown) may be provided on the exterior of the
cylindrical tube 25 at least along distal portion 27. Suitable
coatings include fluoropolymers such as polytetrafluoroethylene
(TEFLON) or hydrophilic materials.
[0050] The inner diameter of cylindrical tube 25 is provided in
suitable diameter to enclose solid cylindrical core wire 26
therein. Generally, inner diameter of cylindrical tube 25 is about
0.005 inch to about 0.036 inch. A typical dimension of uniform
cylindrical tube 25 is 0.016''OD.times.0.009''ID. Nevertheless,
other dimensions may be used.
[0051] The grasping assembly 17 may be any suitable grasping
assembly. As depicted in FIGS. 1 and 2, the grasping assembly 17
has a plurality of arms 20 disposed about the longitudinal axis 21
of the device 11 with proximal arm sections 22 secured to the
distal end 16 of the core member 14 and distal arm sections 23
which extend essentially parallel to the longitudinal axis 21 e.g.
not more than 5.degree. from a line parallel to longitudinal axis
when the grasping assembly 17 is in an expanded configuration as
shown. The distal arm sections 23 have inwardly extending, object
engaging elements 24 at their distal ends. The bluntness of the
object engaging element 17 provides a non-traumatic feature to the
distal end of the arms 20. The proximal portion 25 of the grasping
device 11 is usually of uniform outer diameter and is of sufficient
length so that the proximal end 15 extends out of the delivery
catheter 12 when the grasping assembly 17 extends out the distal
end of the delivery catheter.
[0052] As shown in FIG. 1 the delivery catheter 12 has a tubular
body 30 with an adapter 31 on the proximal end 32, a port 33 in the
adapter 31, a distal end 34, a port 35 in the distal end and an
inner lumen 36 extending between and in fluid communication with
proximal port 33 in the adapter 31 and the distal port 35. A
radiopaque marker 37 is provided on the distal end 34 to facilitate
fluoroscopic observation of the distal end of the delivery catheter
12 during a procedure within a patient's body, such as a
thrombectomy. The inner lumen 36 is configured to slidably receive
the grasping device 11 with the grasping assembly 17 in the
contracted configuration as shown in FIG. 4. The adapter 31 is
preferably provided with a hemostatic valve (not shown).
[0053] Delivery catheter 12 is generally constructed to track over
a conventional guidewire beyond the guide catheter 13 in the
cervical anatomy and into the cerebral vessels associated with the
brain and may also be chosen according to several standard,
"microcatheter" designs that are generally available. Accordingly,
delivery catheter 12 has a length that is at least 125 cm long, and
more particularly may be between about 125 cm and about 175 cm
long. Typically, the delivery catheter 12 is about 155 cm long. The
inner lumen 36 of the delivery catheter generally has an inner
diameter between about 0.01 inch and about 0.08 inch (0.25-2.03
mm). Commercially available microcatheters are generally suitable
for use as delivery catheters.
[0054] Also shown in FIG. 1 is guide catheter 13 has a tubular body
40, a proximal end 41, a distal end 42, and an inner lumen 43
extending between a proximal port 44 in the proximal end and a
distal port 45 in the distal end of the guide catheter. The
proximal end 41 of guide catheter 13 may be provided with an
adapter (not shown) having a hemostatic valve. Guide catheter 13 is
generally constructed to bridge between a femoral artery access
site and a cervical region of the carotid or vertebral artery and
may be chosen according to several standard designs that are
generally available.
[0055] Accordingly, guide catheter 13 is generally at least 85 cm
long, and more particularly may be between about 95 cm and about
105 cm long. Further to conventional and available designs, the
inner lumen 43 of guide catheter 13 generally has an inner diameter
that is between about 0.038 inch and 0.090 inch (0.88-2.29 mm), and
more particularly may be between about 0.052 inch and about 0.065
inch (1.32-1.65 mm).
[0056] Grasping device 11 is configured to slidably fit within the
inner lumen 36 of delivery catheter 12. For procedures involving
distal locations of thromboembolic neurovascular occlusions, the
grasping device 11 is configured to be delivered through the inner
lumen 36 of the delivery catheter 12 with a diameter that is equal
to or less than about 0.042 inches (1.07 mm), preferably less than
about 0.022 inches (0.559 mm). In the case of use in a more distal,
tortuous, and smaller vessel anatomy, configuration for delivery
through a delivery catheter inner lumen less than 0.018 inch (0.457
mm) diameter may be used. For most neurovascular occlusions, the
grasping device 11 is about 135 cm to about 300 cm long, and more
particularly may be about 150 cm to about 200 cm long. Generally,
the grasping device 11 is about 175 cm long and is adapted to be
used in a delivery catheter 12 that is about 150 cm long.
Nevertheless, other values for diameters and lengths are
possible.
[0057] The device as described does not include a tapered core
mandrel as disclosed in U.S. Pat. No. 6,679,893. Instead, the
grasping elements are attached to the distal end of a generally
uniform cylindrical tube in one embodiment.
[0058] Grasping assembly 17 is adjustable between different
configurations, namely, a completely contracted configuration or
nearly contracted configuration as generally shown in FIG. 4 to
facilitate disposition within the inner lumen 36 of delivery
catheter 12. In another arrangement grasping assembly has a
completely expanded configuration or nearly expanded configuration
as generally shown in FIGS. 1, 2 and to facilitate advancement of
the expanded grasping assembly 17 within the body lumen about the
object to be captured. In yet another arrangement, assembly 17 has
a partially contracted configuration to hold onto or capture the
object as generally shown in FIG. 7. Grasping assembly 17 is shown
in FIGS. 1, 2 and 5 in the expanded configuration which is
generally defined by each of the arms 20 in a completely expanded
position and the distal arm sections 23 being generally parallel or
nearly parallel to longitudinal axis 21, which in a preferred
embodiment is the relaxed memory state for the arms 20.
[0059] Grasping assembly 17 is adjustable from the expanded
configuration as generally shown in FIG. 5 to the contracted or
partially contracted configuration by the application of force
against the inclined proximal arm sections 22 by advancing the
distal end 35 of the delivery catheter 12 as shown by the arrow 38
in FIG. 6 against the inclined proximal arm sections.
[0060] Arms 20 may be constructed of various materials having
suitable strength, elasticity and memory for use in engaging and
removing an object such as thrombus from a body lumen, particularly
a cerebral vessel. However, arms 20 are generally constructed from
a metal which may be for example platinum (or alloys thereof),
stainless steel, superelastic shape memory material, or high
strength cobalt-chromium-molybdenum alloys. Platinum or alloys
thereof are preferred because they provide a particular beneficial
combination of a non-traumatic distal tip for the arms 20 and
radiopacity for fluoroscopic observation of the arms in an
intracorporeal procedure.
[0061] There are any number of alternative arrangement for
practicing techniques and aspects of the grasping device 11. More
specific features of the use of the device and system in capturing
and removing, for example, thromboembolic occlusions from the
distal cerebral vessels are described in the foregoing.
Nevertheless, the inventive aspects of the grasping device 11 can
be used for any number of alternative arrangements. Hence, the
following example is illustrative of a method of using the grasping
device 11.
[0062] First, an access site is prepared as either a puncture wound
(i.e. Seldinger technique) or as a surgical cut-down, typically in
the femoral artery although in rare circumstances vascular access
may be made at other peripheral vessels such as a brachial artery.
An introducer (not shown) may be used to provide hemostatic access
at the access site via an incorporated hemostatic valve. Guide
catheter 13 is than advanced through the introducer until distal
end 42 is positioned with distal port 45 at a region of a cervical
vessel 50, thereby providing transluminal access to the cervical
vascular tree as shown in FIG. 7. Delivery catheter 12 is advanced
through the inner lumen 43 of guide catheter 13 and out the distal
port 45 thereof until the distal end 34 of the delivery catheter is
positioned adjacent to the thromboembolism 50 located in the middle
cerebral artery 51.
[0063] In the case where the distal location of the thromboembolism
is beyond a bifurcated vessel or otherwise tortuous cerebral
vessels, the delivery catheter 12 may be advanced over a
conventional guide wire (not shown). Once the delivery catheter 12
is positioned adjacent to the thromboembolism 50, the guide wire is
removed from the patient and is then replaced with grasping device
11. Grasping device 11 is advanced through the inner lumen 36 of
the delivery catheter in the contracted configuration as shown in
FIG. 5, until it exits through distal port 35 into the blood vessel
51 where the grasping assembly 17 self-adjusts to the expanded
configuration with arms 20 in a radially expanded position.
Grasping assembly 17 is then advanced, as indicated by the arrow
52, in the expanded configuration distally so that arms 20 advance
around the thromboembolism 50 as shown in FIG. 5. Then, delivery
catheter 12 is advanced distally to press against proximal arm
sections 22 to force distal arm sections 23 to rotate radially
inwardly to a partially contracted configuration so that the object
engaging members 24 engage the thromboembolism 50 as shown in FIG.
7. Thereafter, the grasping device 11, delivery catheter 12, and
thromboembolism 50 may be removed from the location and further
from the body, either through guide catheter 13 or together in
combination with guide catheter.
[0064] FIGS. 8A-8C schematically illustrate an alternative
intracorporeal grasping system 610. Intracorporeal grasping system
610 includes at least one jaw 70 and a scoop 71 used to extract the
object to be captured between the jaw 70 and scoop 71. The scoop
may be a rigid member 72 that extends from tube 30 as shown in FIG.
8A, or a catheter scoop 73 formed by cutting away the tip of tube
30 to form a scoop as shown in FIG. 8B and FIG. 8C. A single jaw is
depicted in these figures; however, more than one jaw may be used.
The cutting operation to form the scoop 73 can be a suitable method
such as laser cutting.
[0065] The jaw 70 is generally disposed along the longitudinal axis
74 and has a proximal arm section 75 secured to the distal end 16
of the elongate core member 14. The proximal arm section 75 is
inclined from the distal end 16 of the elongate core member 14. The
inclined proximal arm section 75 functions to aid in placing the
jaw 70 of the grasping assembly 17 into a contracted or partially
contracted configuration about the longitudinal axis 74 by the
force applied to the inclined section by advancement of the distal
end of the delivery catheter 12 and has a length selected to
provide the desired radial spacing between the distal arm section
76 and the scoop 71. An inwardly extending object engaging element
77 is disposed at the distal end of jaw 70. The jaw 70 typically
extends beyond the length of the scoop as shown in FIG. 8A.
[0066] In one operation, the scoop 71 is forced, wedged, or placed
under the object to be captured. The jaw 70 extends beyond the
length of the scoop and is retracted by moving the elongate core
member 14 inward distally. As the jaw 70 is being retracted, it is
forced to bite down on the object towards the longitudinal axis 74.
When jaw 70 engages the object it then pulls the object along the
length of the scoop 71 into tubular body 30 for removal.
[0067] Jaw 70 may be constructed from a flat ribbon or wire. Jaw 70
may be constructed of various materials having suitable strength,
elasticity and memory for use in engaging and removing an object
such as thrombus from a body lumen, particularly a cerebral vessel.
In one embodiment, jaw 70 may be generally constructed from a metal
which may be for example platinum (or alloys thereof), stainless
steel, super-elastic nickel-titanium alloy, or high strength
cobalt-chromium-molybdenum alloys.
[0068] Rigid member 72 may be constructed of various materials
having suitable strength and is generally constructed from a metal
which may be for example platinum (or alloys thereof), stainless
steel, super-elastic nickel-titanium alloy, or high strength
cobalt-chromium-molybdenum alloys.
[0069] FIGS. 9A-9C schematically illustrate an alternative
intracorporeal grasping system 210. A grasping configuration 217 is
provided for capturing an object (e.g., clot or debris) therein, in
which the grasping configuration comprises unitarily formed
plurality of movable jaws 90 attached to the distal end portion of
the elongated core member 214. It is noted that core member 214 can
have the construction of core member 14 as well as other
constructions.
[0070] In another embodiment, jaws 90 are formed from thin tubing
96 which is cut, e.g. with a laser, to form narrow jaws 90. (See
FIG. 9A). Each jaw 90 has a proximal arm section 91 extending from
tubing 96. As shown in FIG. 9B, the proximal arm section 91 is
inclined from the tubing 96. The inclined proximal arm section 92
functions to aid in placing the jaws 90 of the grasping
configuration 217 into a contracted or partially contracted
configuration about the longitudinal axis 94 by the force applied
to the inclined section by advancement of the distal end of the
delivery catheter 12 (FIGS. 1-2) and has a length selected to
provide the desired radial spacing between the distal arm sections
92. Inwardly extending object engaging elements 93 are disposed at
the distal end of jaws 90.
[0071] Tube 96 is disposed onto the distal end of the elongate core
member 214, as shown in FIG. 9B and adhered into place or fastened
or otherwise attached thereto. In operation, the jaws 90 extend
along a length of the object to be removed and are retracted by
retracting elongate core member 14. As the jaws are being
retracted, they are forced to bite down on the object and then pull
the object into tubular body 30.
[0072] As with various jaws disclosed herein, jaws 90 may be
constructed of various materials having suitable strength,
elasticity and memory for use in engaging and removing an object
such as thrombus from a body lumen, particularly a cerebral vessel.
However, jaws 90 are generally constructed from a metal which may
be for example platinum (or alloys thereof), stainless steel,
super-elastic nickel-titanium alloy, or high strength
cobalt-chromium-molybdenum alloys.
[0073] It is noted that jaw assemblies generally have an inwardly
extending object engaging elements disposed at the distal end of
jaws. This is shown in the embodiments of FIGS. 8-9 above, for
example. In further embodiments, the jaws may contain engaging
elements. The jaws may be suitable jaws as any embodiments
described herein. FIGS. 10A-10F illustrates alternative arrangement
of jaws with various engaging elements for removing a thrombus, for
example.
[0074] Engaging elements allow the jaw to grip the object to be
removed. In addition to engaging elements 24 in FIG. 10A, a
plurality of engaging elements can be applied to arm segment 22
and/or arm segment 23 (e.g., FIGS. 1-4). The engaging elements 101
extend towards the object to be removed and may be applied as a
separate member for the arm segments, such as by soldering as shown
in FIG. 10A. Alternatively, the engaging elements may be formed by
cutting tabs 102 in the arm segments and bending inward as shown in
FIG. 10B, or by pressing grooves or ribs 103 onto the inside
surface of the ribbon forming a jaw as shown in FIG. 10C.
[0075] In one arrangement, the arm segment 23 with engaging
elements may include a distal blunt edge 105 as shown in FIG. 10D
or arm segment 23' with a distal sharp edge or distal "bladed" edge
107 as shown in FIGS. 10E-F. A distal blunt edge 105 is useful for
grabbing the debris and pulling into the tubular member 30. As
shown in FIG. 10D, the distal portion can be angled inward more
than 90 degrees from the horizontal as denoted by angle "A". For
example, the angle may be 91-97 degrees or 93-95 degrees.
Additionally, the distal sharp edge 107 is useful for grabbing the
debris and pulling into the tubular member 13, but also useful for
cutting or biting off chunks of the debris (clot), for example, if
the debris is too large to remove in as a single unit.
[0076] As shown in FIG. 1, jaws can be formed of a unitary piece of
ribbon or wire, such as platinum ribbon or wire, which is bent into
a U or V shape. Nevertheless, other shapes are possible. The two
edges of the ribbon or wire form two jaws which include two arm
segments 22, 23 and two engaging elements 24. The ribbon or wire is
attached to elongate core member 14 such as via coil 19.
[0077] FIGS. 12A-12E schematically illustrate an alternative
embodiment for a grasping assembly component. As shown in FIGS.
12A-12E, the jaws 300 may be formed from tubing having a desired
cross-section, such as a circular 301, rectangular 303, triangular
305, oval 310 or other shape to provide benefits of grasping
objects in a human body or surgical benefits. The hollow interior
of the tube forms a lumen 307 which can be used to inject or
deliver fluidic substances or medicament to the object to be
removed at the distal end 309. In one embodiment, the distal end
309 of the jaws 300 has an aperture for delivering fluids. In one
example, a substance might be injected though the jaws 300 in order
to soften the object to be removed. Nevertheless, different type of
substances can be provided. Alternatively, a vacuum may be applied
to the tube to remove fluids or to provide a negative pressure
region at the distal end 309 of the jaws 300 to remove portions of
the object designated for removal or other debris.
[0078] FIGS. 13A-13E illustrate an alternative intracorporeal
grasping system 400. At least one jaw member collectively defines a
loop configuration 405 to advantageously increase the
coverage/grasping area of the objects to be grabbed and removed
from the human body. Further, the loops retains the object
specifically between the contact other loops. Hence, the grasping
element 17 can be formed from a plurality of loops 405 (such as two
loops) which engaged each to capture or clamp objects therein.
[0079] While the loop configuration is preferably a circle, it
could be in the form of a myriad of different closed loops
including without limitation ovals, squares and irregular shapes.
Nevertheless, other shapes can be used. The loop should simply
define a substantially closed configuration to retain the object
therein. The loops can be of different shapes and forms and various
cross-sections as is suitable for the particular type and shape of
object to be removed. For example the loops may have a spatula
shape as shown in FIG. 13A or a spoon shape as shown in FIG.
13B.
[0080] The loops are attached to the elongate core member 14 such
as a core wire or, as shown in FIG. 13D, coil 19. The outer tubular
member 30 moves forward to bring the loops together and apart as
shown in FIG. 13C. The grasping assembly can also combine loops
with jaws as shown in FIG. 13C. The loop would encircle a larger
surface area of the object to be removed whereas the jaws would
clamp onto the object to be removed. The arrangement of loops and
jaws provides an increase of total surface area than jaws alone,
but allows the object to be grabbed into and held. It should be
noted that the embodiment of FIGS. 13A-D may be constructed with
tubing having a wall with perforations for releasing a fluid within
the tubing as disclosed in the embodiments of FIGS. 12A-12E.
[0081] Loops 405 may be formed from ribbon or wire. Loops 405 may
be constructed of various materials having suitable strength,
elasticity and memory for use in engaging and removing an object
such as thrombus from a body lumen, particularly a cerebral vessel.
However, loops are generally constructed from a metal which may be
for example platinum (or alloys thereof), stainless steel,
super-elastic nickel-titanium alloy, or high strength
cobalt-chromium-molybdenum alloys.
[0082] FIGS. 14A-14D illustrate an alternative intracorporeal
grasping system 500. A grasping assembly 501 may be formed in a web
configuration such with webbed jaws. Webbed jaws provide stronger
and increased coverage or encapsulation of the object to be removed
than jaws without webs. The web may be constructed by attaching
fiber or welding metallic strands to the individual grasping
mechanism.
[0083] The webs may be formed from ribbon as shown in FIGS. 14A-14C
or wire as shown in FIG. 14D. The webs connect between jaws in a
concave or convex manner as shown in FIG. 14B or 14C as are
flexible to bend or stretch based on the movement of elongate
member 14 into and out of tube 30.
[0084] Webs 110 can be attached during jaw formation, or they can
be formed from the same piece of the jaws. The jaws can be made in
a manner similar to a laser cut stent, so webs and jaws are one
piece (cut tubing). Webs 110 may be constructed of various
materials having suitable strength, elasticity and memory for use
in engaging and removing an object such as thrombus from a body
lumen, particularly a cerebral vessel. However, loops are generally
constructed from a metal which may be for example platinum (or
alloys thereof), stainless steel, super-elastic nickel-titanium
alloy, or high strength cobalt-chromium-molybdenum alloys.
[0085] FIGS. 15A-15B illustrate an alternative intracorporeal
grasping system 100. The proximal arm sections and distal arm
sections may have different lengths and can be offset for different
specific intended procedures. As shown in FIG. 15A, opposing pairs
of jaws 111 comprising proximal arm 115 section and distal arm
section 116 having a longer longitudinal length (as measured from
the distal end 16 of core member 14) than the longitudinal length
opposing pairs of jaws 112 comprising proximal arm 117 section and
distal arm section 118. Hence, the jaws 111 and 112 are offset from
each other a longitudinal distance denoted as "delta X" or simply
"X". The jaws 111 and 112 are offset from each other such that when
tube 30 slidably engages the periphery of the jaws, the longer jaws
111 will contract before the shorter jaws 112. The offsetting
feature of the jaws enables the jaws 111, 112 to clamp down at
different times during longitudinal movement of the lumen 30
towards to the jaws 111, 112. Each jaw may be offset relative to
the other jaws or pairs of jaws may be offset relative to other
pairs of jaws. Nevertheless, other configurations are possible for
the grasping system 100.
[0086] FIGS. 16A-16C illustrate an alternative intracorporeal
grasping system. Elongate core member 14 comprises an elongate tube
120 positioned within tube 30. Jaws 121 are attached to or formed
at the distal end of elongate tube 120 as shown in FIG. 16A such
that when core member 14 is withdrawn into tube 30, the jaws clamp
down on an object to be removed. Referring to FIG. 16C, the
elongated tube 120 may have a multi-flexion configuration that has
separate regions of different flexions that each correspond to the
flexibility, or lack thereof, for improved transluminal
manipulation. This multi-flexion regional configuration provides
adaptability for a practitioner to reduce steps for accessing or
grasping an object or customize the access in body lumens to
increase patient comfort. This feature incorporates the features of
grasping system 10 as discussed in the foregoing.
[0087] Generally concentrically located within elongate tube 120 is
elongate cylindrical member 123 having a spiral-shaped member 122
(e.g., corkscrew-like member) attached to a distal end thereof. The
elongate cylindrical tube 120 may be tapered in one embodiment. The
member 123 may have various dimensional characteristics. In one
example, the outer diameter ("OD") at the distal end of the
cylindrical member 123 may be 0.012 inches. The spiral-shaped
member 122 may be formed with a wire having an OD about may be
0.008 inches to 0.010 inches. Nevertheless, other configurations
and dimensions are possible within the scope of the invention. The
spiral shaped member 122 may be formed integrally with the distal
end of the cylindrical member 123.
[0088] The spiral-shaped member 122 engages into an object to be
removed (e.g., clot 50) via rotational movement about a
longitudinal axis 125. The distal end 127 of the spiral-shaped
member 122 includes sharpen tip for penetrating into the interior
of the clot during the rotational movement. Once the clot is
engaged by member 122, then the elongate tube 120 is withdrawn into
tube 30. Elongate tube 120 is preferably flexible. The jaws 121 may
be attached to the inside or outside of the tube 120 or may be
formed from the tube itself as disclosed in alternative embodiment
herein (e.g., FIGS. 8A-8C, and 9A-9C). Nevertheless, other
configurations and arrangements are possible.
[0089] FIGS. 17A-17D illustrate an alternative embodiment of a
grasping device according to the teaching of the present invention.
Jaws 20 are made of wire having a generally circular cross-section.
It was discovered that the circular cross-section of the jaws
allows the jaws to be easily inserted and aligned evenly in coil 19
(See FIG. 17A) or other concentric tube or guidewire. The jaws are
more flexible than conventional jaws, which allow a better grip on
the object to be removed.
[0090] At least six, preferably eight to twelve, wire jaws 20 are
integrally secured to the distal end 16 of the elongate core member
14 and disposed about the longitudinal axis 21. Outer tubular body
30 (see FIG. 1) surrounds the jaws 20 and coil 19.
[0091] Each jaw 20 has a proximal arm section 22 secured to the
distal end 16 of the elongate core member 14. The proximal arm
section 22 is inclined from the distal end 16 of the core member
14. The inclined proximal arm section 22 functions to aid in
placing the jaws 20 of the grasping assembly 17 into a contracted
or partially contracted configuration about the longitudinal axis
21 by the force applied to the inclined section by advancement of
the distal end of the delivery catheter 12 and has a length
selected to provide the desired radial spacing between the distal
arm sections 23.
[0092] In operation, the jaws 20 extend along a length of the
object to be removed and are retracted by retracting elongate core
member 14. As the jaws are being retracted, they are forced to bite
down on the object and then pull the object into tubular body
30.
[0093] Jaws 20 may be constructed of various materials having
suitable strength, elasticity and memory for use in engaging and
removing an object such as thrombus from a body lumen, particularly
a cerebral vessel. However, jaws 20 are generally constructed from
a metal which may be for example platinum (or alloys thereof),
stainless steel, super-elastic nickel-titanium alloy, or high
strength cobalt-chromium-molybdenum alloys.
[0094] While the arrangements and various embodiments described are
believed to be well suited for engaging and removing various
objects from various body spaces, the primary basis underlying many
of the beneficial features herein described are for the purpose of
accessing distal, tortuous cerebral vessels for removal of
thromboembolism in the treatment of strokes, as previously
described above. Nevertheless, other purposes of devices can be
advantageously applied to other biological organisms.
[0095] There are any number of alternative arrangement for
practicing techniques and aspects herein. For example, an
intracorporeal grasping device may include a tubular member for
entering a lumen of a human body and the tube member having a
distal end portion. An elongated core member is disposed with the
interior cavity of the tubular member for rotational or slidably
movement within the tubular member and the elongated core member
having a proximal end portion and a distal end portion. A grasping
configuration is provided for capturing an object (e.g., clot or
debris) therein in which the grasping configuration is formed by at
least one movable jaw attached to the distal end portion of the
elongated core member and a length portion of the distal end
portion of the tube member. The grasping configuration may include
unitarily formed plurality of movable jaws attached to the distal
end portion of the elongated core member. Further, the grasping
configuration may be formed by a plurality of loop members attached
to the distal end portion of the elongated core member.
[0096] In another example, an intracorporeal grasping device
includes a tubular member for entering a lumen of a human body and
the tubular member having a distal end portion. An elongated core
member being disposed with the tubular member and the elongated
core member having a proximal end portion and a distal end portion.
A grasping configuration is provided for capturing an object
therein, in which the grasping configuration is formed by at least
one spiral member having a distal tip for penetrating an object to
be removed from a human body lumen. The device has the spiral
member provided at the distal end portion of the elongated core
member. The grasping configuration can be formed by at least one
web member for retaining an object to be removed from a human body
lumen, the web member being provided at the distal end portion of
the elongated core member.
[0097] There are any number of alternative combinations for
defining the invention, which incorporate one or more elements from
the specification, including the description, and drawings and
claims, in various combinations or sub combinations. It will be
apparent to those skilled in the relevant technology, in light of
the present specification, that alternate combinations of aspects
of the invention, either alone or in combination with one or more
elements or steps defined herein, may be utilized as modifications
or alterations of the invention or as part of the invention. It may
be intended that the written description of the invention contained
herein covers all such modifications and alterations.
* * * * *