U.S. patent application number 12/320371 was filed with the patent office on 2009-08-06 for medical retrieval devices.
This patent application is currently assigned to Scimed Life Systems, Inc.. Invention is credited to Dave Ziegler.
Application Number | 20090198249 12/320371 |
Document ID | / |
Family ID | 34969490 |
Filed Date | 2009-08-06 |
United States Patent
Application |
20090198249 |
Kind Code |
A1 |
Ziegler; Dave |
August 6, 2009 |
Medical retrieval devices
Abstract
A medical retrieval device includes a retrieval assembly
comprising a plurality of filaments knotted together at a distal
end of the retrieval assembly. The knotted distal end provides the
device with an atraumatic distal tip. Various knotting arrangements
can be used at the knotted distal end. The retrieval assembly can
be collapsed when restrained and expanded when unrestrained.
Inventors: |
Ziegler; Dave; (Bedford,
IN) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Scimed Life Systems, Inc.
|
Family ID: |
34969490 |
Appl. No.: |
12/320371 |
Filed: |
January 23, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10853052 |
May 25, 2004 |
7491211 |
|
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12320371 |
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Current U.S.
Class: |
606/127 |
Current CPC
Class: |
A61B 2017/2212 20130101;
A61B 17/221 20130101 |
Class at
Publication: |
606/127 |
International
Class: |
A61B 17/22 20060101
A61B017/22 |
Claims
1-26. (canceled)
27. A medical retrieval device, comprising: a sheath; and a
retrieval assembly comprising a plurality of filaments knotted
together in a barrel knot to form a knotted distal end of the
retrieval assembly, the retrieval assembly being collapsed when
restrained by the sheath and expanded when unrestrained by the
sheath.
28. The medical device of claim 27, wherein the barrel knot
comprises: (a) the plurality of filaments coiled to form a first
set of at least two concentric loops, each loop defining a lumen;
and (b) a first overhand knot tied with the plurality of parallel
filaments through the lumens of the first set of at least two
concentric loops to form the barrel knot at the knotted distal end
of the retrieval assembly.
29. The medical device of claim 27, wherein the barrel knot
comprises: (a) the plurality of filaments grouped together and bent
to form a loop defining a lumen wherein an end of the filaments
crosses a portion of the filaments; and (b) the end of the
filaments wound around the grouped filaments and through the lumen
of the loop two or more times to form the barrel knot at the
knotted distal end of the retrieval assembly.
30. The medical retrieval device of claim 27, wherein the knotted
distal end does not include an adhesive.
31. The medical retrieval device of claim 27, wherein the knotted
distal end includes an adhesive.
32. The medical retrieval device of claim 27, wherein at least one
filament forms two legs of the retrieval assembly.
33. A retrieval assembly, comprising: a barrel knot, comprising (a)
a plurality of filaments; (b) the plurality of filaments coiled to
form a first set of at least two concentric loops, each loop
defining a lumen; and (c) a first overhand knot tied with the
plurality of parallel filaments through the lumens of the first set
of at least concentric two loops to form the barrel knot at the
knotted distal end of the retrieval assembly.
34. The retrieval assembly of claim 33, further comprising a second
set of at least two concentric loops formed by coiling the
plurality of parallel filaments, and a second overhand knot tied
with the plurality of filaments through the lumens of the second
set of at least two concentric loops.
35. The retrieval assembly of claim 33, wherein the knotted distal
end does not include an adhesive.
36. The retrieval assembly of claim 33, wherein the knotted distal
end includes an adhesive.
37. The retrieval assembly of claim 33, wherein at least one
filament forms two legs of the retrieval assembly.
38. The retrieval assembly of claim 33, wherein the number of
concentric loops is the same as the number of filaments.
39. The retrieval assembly of claim 33, wherein the number of
concentric loops is less than the number of filaments.
40. The retrieval assembly of claim 33, wherein the number of
concentric loops is greater than the number of filaments.
41. A retrieval assembly, comprising: a barrel knot including (a) a
plurality of filaments grouped together; (b) the grouped filaments
bent to form a loop defining a lumen wherein an end of the
filaments crosses a portion of the filaments; and (c) the end of
the filaments wound around the grouped filaments and through the
lumen of the loop two or more times to form the barrel knot at a
knotted distal end of the retrieval assembly.
42. The retrieval assembly of claim 41, wherein the knotted distal
end does not include an adhesive.
43. The retrieval assembly of claim 41, wherein the knotted distal
end includes an adhesive.
44. The retrieval assembly of claim 41, wherein at least one
filament forms two legs of the retrieval assembly.
45. The retrieval assembly of claim 41, wherein the number of times
the ends of the filaments are wound around the grouped filaments
and through the lumen is the same as the number of filaments.
46. The retrieval assembly of claim 41, wherein the number of times
the ends of the filaments are wound around the grouped filaments
and through the lumen is less than the number of filaments.
47. The retrieval assembly of claim 41, wherein the number of times
the ends of the filaments are wound around the grouped filaments
and through the lumen is greater than the number of filaments.
Description
TECHNICAL FIELD
[0001] The invention generally relates to medical retrieval devices
such as those with retrieval assemblies for retrieving material
from the body of a mammal.
BACKGROUND INFORMATION
[0002] Certain medical procedures and treatments involve the use of
retrieval devices with retrieval assemblies for capturing material
from within bodies of patients, such as kidney stones and/or other
materials. Commonly, these retrieval assemblies, such as, for
example, basket assemblies, are constructed using multiple
filaments such that a basket having a plurality of legs is
formed.
SUMMARY OF THE INVENTION
[0003] The ends of a retrieval assembly may be formed by twisting
or knotting filaments together at the distal end of the retrieval
assembly. Certain knots can be difficult to make at least in part
because they are difficult to tie. Certain knots also may fail to
fix the radial position of the filaments, resulting in "play"
and/or unintended angles between the filaments. As a result, damage
to the filaments and operator fatigue during manufacture of the
retrieval assembly wastes materials and increases manufacturing
time.
[0004] The invention generally relates to various types of knots at
the distal end of a medical device retrieval assembly, such as a
basket assembly. The basket assembly has an atraumatic tip, in that
the tip does not have any significant distal protrusion or outward
projection that can poke tissue, pierce tissue, otherwise cause
trauma to tissue, or inhibit or hinder capturing of material from
within the body of a patient. The knots at the distal end of the
basket assembly generally fix the position of the filaments that
are tied together to form the knots, and the knots help to prevent
unintended angles from forming between the filaments. The knots
also allow for retrieval assemblies to have an odd or even number
of legs.
[0005] In one aspect, the invention generally involves a medical
retrieval device comprising a sheath and a retrieval assembly. The
retrieval assembly includes a plurality of filaments knotted
together in a flipped double overhand knot to form a knotted distal
end of the retrieval assembly. The retrieval assembly is collapsed
when restrained by the sheath and expanded when unrestrained by the
sheath.
[0006] In a related aspect, the invention generally involves a
method of making a flipped double overhand knot at the distal end
of a retrieval assembly. The method includes providing a first
filament comprising a first end and a second end, and providing a
second filament comprising a first end and a second end. The second
filament is laid across and substantially perpendicular to the
first filament. The second end of the first filament is placed
across the first end of the first filament and a first overhand
knot is tied with the first filament around the second filament.
The second end of the second filament is placed across the first
end of the second filament and a second overhand knot is tied with
the second filament around the first filament to form the flipped
double overhand knot at the distal end of the retrieval assembly.
The invention comprises a retrieval device including such a
retrieval assembly.
[0007] In another aspect, the invention generally involves a
medical retrieval device comprising a sheath and a retrieval
assembly. The retrieval assembly includes a plurality of filaments
knotted together in a carrick bend knot to form a knotted distal
end of the retrieval assembly. The retrieval assembly is collapsed
when restrained by the sheath and expanded when unrestrained by the
sheath.
[0008] In a related aspect, the invention generally features a
method of making a carrick bend knot at the distal end of a
retrieval assembly. The method comprises providing a first filament
comprising a first end and a second end, and providing a second
filament comprising a first end and a second end. The first
filament is bent wherein the second end of the first filament
crosses the first end of the first filament to form a first loop
defining a lumen. The first loop is placed on top of the second
filament. The second filament is bent wherein the first end of the
second filament crosses the second end of the first filament and is
placed under the first end of the first filament to form a second
loop. The first end of the second filament is placed through the
lumen of the first loop and under the second filament, and the
first end of the second filament is pulled through the lumen of the
first loop to form the carrick bend knot at the distal end of the
retrieval assembly.
[0009] Another aspect of the invention generally relates to a
medical retrieval device comprising a sheath and a retrieval
assembly. The retrieval assembly includes a plurality of filaments
knotted together in a water/webbing knot to form a knotted distal
end of the retrieval assembly. The retrieval assembly is collapsed
when restrained by the sheath and expanded when unrestrained by the
sheath.
[0010] In a related aspect, the invention generally involves a
method of making the water/webbing knot at the knotted distal end
of the retrieval assembly. The method comprises providing three or
more parallel filaments grouped together. An overhand knot is tied
with the three or more parallel filaments to form the water/webbing
knot at the knotted distal end of the retrieval assembly.
[0011] A further aspect of the invention generally features a
medical retrieval device comprising a sheath and a retrieval
assembly. The retrieval assembly comprises a plurality of filaments
knotted together in a barrel knot to form a knotted distal end of
the retrieval assembly. The retrieval assembly is collapsed when
restrained by the sheath and expanded when unrestrained by the
sheath.
[0012] A related aspect of the invention generally features a
method of making the barrel knot at the knotted distal end of the
retrieval assembly. The method includes providing a plurality of
parallel filaments. The plurality of parallel filaments are coiled
to form a first set of at least two loops, each loop defining a
lumen. A first overhand knot is tied with the plurality of parallel
filaments through the lumens of the first set of at least two loops
to form the barrel knot at the knotted distal end of the retrieval
assembly. In one embodiment, the plurality of parallel filaments
are coiled to form a second set of at least two loops, each loop
defining a lumen, and a second overhand knot is tied with the
plurality of parallel filaments through the lumens of the second
set of at least two loops.
[0013] In another related aspect, the invention generally involves
a method of making the barrel knot at the knotted distal end of the
retrieval assembly. The method includes providing a plurality of
filaments grouped together. The grouped filaments are bent to form
a loop defining a lumen wherein an end of the filaments crosses a
portion of the filaments, and the end of the filaments are wound
around the grouped filaments and through the lumen of the loop two
or more times to form the barrel knot at the knotted distal end of
the retrieval assembly.
[0014] In another aspect, the invention generally features a
medical retrieval device comprising a sheath and a retrieval
assembly. The retrieval assembly includes a plurality of filaments
knotted together in a fisherman's knot to form a knotted distal end
of the retrieval assembly. The retrieval assembly is collapsed when
restrained by the sheath and expanded when unrestrained by the
sheath.
[0015] In a related aspect, the invention generally involves a
method of making the fisherman's knot at the knotted distal end of
the retrieval assembly. In one embodiment, the method includes
providing a first filament comprising a first end and a second end,
and providing a second filament comprising a first end and a second
end. A first overhand knot is tied around the second filament with
the first end of the first filament. A second overhand knot is tied
around the first filament with the second end of the second
filament to form the fisherman's knot at the knotted distal end of
the retrieval assembly. In another embodiment the method includes
providing a plurality of filaments grouped together. The grouped
filaments are bent to form a loop defining a lumen wherein an end
of the filaments crosses a portion of the filaments. The end of the
filaments are wound around the grouped filaments and through the
lumen of the loop two or more times to form the barrel knot at the
knotted distal end of the retrieval assembly.
[0016] In yet another aspect, the invention generally relates to a
medical retrieval device comprising a sheath and a retrieval
assembly. The retrieval assembly includes a plurality of filaments
knotted together in a surgeon's knot to form a knotted distal end
of the retrieval assembly. The retrieval assembly is collapsed when
restrained by the sheath and expanded when unrestrained by the
sheath.
[0017] A related aspect of the invention generally involves a
method of making the surgeon's knot at the knotted distal end of
the retrieval assembly. The method includes providing a first
filament comprising a first end and a second end, and providing a
second filament comprising a first end and a second end. The first
filament is bent to form a first loop defining a lumen, wherein the
first end of the first filament is substantially parallel to the
second end of the first filament. The first loop is laid on top of
and substantially perpendicular to the second filament. The first
end of the second filament and the second end of the second
filament are placed through the lumen of the first loop to form a
second loop around the first filament. The second loop defines a
lumen. The first end of the second filament is wound through the
lumen of the first loop and around the first filament at least one
time. The second end of the first filament is wound through the
lumen of the second loop and around the second filament at least
one time to form the surgeon's knot at the knotted distal end of
the retrieval assembly.
[0018] In another related aspect, the invention generally features
a method of making the surgeon's knot at the knotted distal end of
the retrieval assembly by providing first and second filaments
wherein the first filament is bent to form a first loop defining a
lumen with a first end of the first filament being substantially
parallel to a second end of the first filament. The first loop is
laid on top of and substantially perpendicular to the second
filament. A first end of the second filament and a second end of
the second filament are placed through the lumen of the first loop
to form a second loop around the first filament. The second loop
defines a lumen. The second end of the second filament is wound
through the lumen of the first loop and around the first filament
at least one time. The first end of the first filament is wound
through the lumen of the second loop and around the second filament
at least one time to form the surgeon's knot at the knotted distal
end of the retrieval assembly.
[0019] In another related aspect, the invention generally involves
a method of making the surgeon's knot at the knotted distal end of
the retrieval assembly by winding the first filament around the
second filament at least three times and tying an overhand knot
with the first end of the second filament and the second end of the
first filament to form the surgeon's knot at the knotted distal end
of the retrieval assembly.
[0020] In another aspect, the invention generally features a
retrieval assembly comprising a flipped double overhand knot. The
flipped double overhand knot includes a first filament comprising a
first end and a second end and a second filament comprising a first
end and a second end. The second filament is placed across and
substantially perpendicular to the first filament. The second end
of the first filament is placed across the first end of the first
filament and a first overhand knot is tied with the first filament
around the second filament. The second end of the second filament
is placed across the first end of the second filament and a second
overhand knot tied with the second filament around the first
filament to form the flipped double overhand knot at the knotted
distal end of the retrieval assembly.
[0021] A further aspect of the invention generally involves a
retrieval assembly comprising a carrick bend knot. The carrick bend
knot includes a first filament comprising a first end and a second
end and a second filament comprising a first end and a second end.
The first filament is bent wherein the second end of the first
filament crosses the first end of the first filament to form a
first loop defining a lumen. The first loop is placed on top of the
second filament, and the second filament is bent wherein the first
end of the second filament crosses the second end of the first
filament and is placed under the first end of the first filament to
form a second loop. The first end of the second filament is placed
through the lumen of the first loop and under the second filament,
and the first end of the second filament is pulled through the
lumen of the first loop to form the carrick bend knot at the
knotted distal end of the retrieval assembly.
[0022] In yet another aspect, the invention generally relates to a
retrieval assembly comprising a water/webbing knot. The
water/webbing knot includes three or more parallel filaments
grouped together and an overhand knot is tied with the three or
more parallel filaments to form the water/webbing knot at the
knotted distal end of the retrieval assembly.
[0023] Another aspect of the invention generally features a
retrieval assembly comprising a barrel knot. The barrel knot
includes a plurality of parallel filaments, and the plurality of
parallel filaments are coiled to form a first set of at least two
loops, with each loop defining a lumen. A first overhand knot is
tied with the plurality of parallel filaments through the lumens of
the first set of at least two loops to form the barrel knot at the
knotted distal end of the retrieval assembly.
[0024] In one embodiment, the barrel knot further comprises the
plurality of parallel filaments coiled to form a second set of at
least two loops, each loop defining a lumen, and a second overhand
knot tied with the plurality of parallel filaments through the
lumens of the second set of at least two loops.
[0025] In another aspect, the invention generally relates to a
retrieval assembly comprising a barrel knot including a plurality
of filaments grouped together, and the grouped filaments are bent
to form a loop defining a lumen wherein an end of the filaments
crosses a portion of the filaments. The end of the filaments is
wound around the grouped filaments and through the lumen of the
loop two or more times to form the barrel knot at the knotted
distal end of the retrieval assembly.
[0026] Another aspect of the invention generally involves a
retrieval assembly comprising a fisherman's knot. The fisherman's
knot includes a first filament having a first end and a second end,
and a second filament having a first end and a second end. A first
overhand knot is tied around the second filament with the first end
of the first filament and a second overhand knot is tied around the
first filament with the second end of the second filament to form
the fisherman's knot at the knotted distal end of the retrieval
assembly.
[0027] In yet another aspect, the invention generally features a
retrieval assembly comprising a surgeon's knot. The surgeon's knot
includes a first filament comprising a first end and a second end,
and a second filament comprising a first end and a second end. The
first filament is bent to form a first loop defining a lumen,
wherein the first end of the first filament is substantially
parallel to the second end of the first filament. The first loop is
laid on top of and substantially perpendicular to the second
filament, and the first end of the second filament and the second
end of the second filament is placed through the lumen of the first
loop to form a second loop around the first filament, the second
loop defining a lumen. The first end of the second filament is
wound through the lumen of the first loop and around the first
filament at least one time, and the second end of the first
filament is wound through the lumen of the second loop and around
the second filament at least one time to form the surgeon's knot at
the knotted distal end of the retrieval assembly.
[0028] In another aspect, the invention generally relates to a
retrieval assembly comprising a surgeon's knot having a first
filament comprising a first end and a second end, and a second
filament comprising a first end and a second end. The first
filament is bent to form a first loop defining a lumen, wherein the
first end of the first filament is substantially parallel to the
second end of the first filament. The first loop is laid on top of
and substantially perpendicular to the second filament, and the
first end of the second filament and the second end of the second
filament is placed through the lumen of the first loop to form a
second loop around the first filament the second loop defining a
lumen. The second end of the second filament is wound through the
lumen of the first loop and around the first filament at least one
time, and the first end of the first filament is wound through the
lumen of the second loop and around the second filament at least
one time to form the surgeon's knot at the knotted distal end of
the retrieval assembly.
[0029] In yet another aspect, the invention generally involves a
retrieval assembly comprising a surgeon's knot including a first
filament comprising a first end and a second end and a second
filament comprising a first end and a second end. The first
filament is wound around the second filament at least three times,
and an overhand knot is tied with the first end of the second
filament and the second end of the first filament to form the
surgeon's knot at the knotted distal end of the retrieval
assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In the drawings, like reference characters generally refer
to the same parts throughout the different illustrations. The
drawings are not necessarily to scale, emphasis instead generally
being placed upon illustrating the principles of the invention.
[0031] FIG. 1 is a side plan view of a medical retrieval device
with a medical retrieval assembly in a fully-extended or open
position according to an illustrative embodiment of the
invention.
[0032] FIG. 2 is a side plan view of the device depicted in FIG. 1
with the retrieval assembly in a collapsed/retracted position
according to an illustrative embodiment of the invention.
[0033] FIG. 3 depicts a four-leg basket according to an
illustrative embodiment of the invention.
[0034] FIG. 4 depicts a three-leg basket according to an
illustrative embodiment of the invention.
[0035] FIG. 5 depicts a four-leg basket according to another
illustrative embodiment of the invention.
[0036] FIGS. 6A-6B depict the steps in constructing an embodiment
of an illustrative overhand knot according to an illustrative
embodiment of the invention.
[0037] FIGS. 7A-7B depict the steps in winding a first filament
around a second filament according to an illustrative embodiment of
the invention.
[0038] FIG. 8 depicts an end-view of a flipped double overhand knot
at the distal end of a medical retrieval assembly according to an
illustrative embodiment of the invention.
[0039] FIGS. 9A-9D depict the steps of making the flipped double
overhand knot illustrated in FIG. 8 according to an illustrative
embodiment of the invention.
[0040] FIG. 10 depicts an end-view of a carrick bend knot at the
distal end of a medical retrieval assembly according to an
illustrative embodiment of the invention.
[0041] FIGS. 11A-11C depict the steps in making the carrick bend
knot illustrated in FIG. 10 according to an illustrative embodiment
of the invention.
[0042] FIG. 12 depicts an end-view of another embodiment of a
carrick bend knot according to an illustrative embodiment of the
invention.
[0043] FIG. 13 depicts a side-view of a water/webbing knot at the
distal end of a medical retrieval assembly according to an
illustrative embodiment of the invention.
[0044] FIGS. 14A-14C depict the steps in making the water/webbing
knot illustrated in FIG. 13 according to an illustrative embodiment
of the invention.
[0045] FIGS. 15A-15B depict an end-view of the water/webbing knots
in which three filaments are joined together at the distal end of a
medical retrieval assembly according to an illustrative embodiment
of the invention.
[0046] FIG. 16 depicts a barrel knot at the distal end of a medical
retrieval assembly according to an illustrative embodiment of the
invention.
[0047] FIGS. 17A-17C depict one series of steps in making the
barrel knot illustrated in FIG. 16 according to an illustrative
embodiment of the invention.
[0048] FIGS. 18A-18C depict another series of steps in making the
barrel knot illustrated in FIG. 16 according to an illustrative
embodiment of the invention.
[0049] FIG. 19 depicts another barrel knot at the distal end of a
medical retrieval assembly according to an illustrative embodiment
of the invention.
[0050] FIG. 20 depicts another barrel knot at the distal end of a
medical retrieval assembly according to an illustrative embodiment
of the invention.
[0051] FIG. 21 depicts a fisherman's knot at the distal end of a
medical retrieval assembly according to an illustrative embodiment
of the invention.
[0052] FIGS. 22A-22B depict one series of steps in making the
fisherman's knot in FIG. 20 according to an illustrative embodiment
of the invention.
[0053] FIG. 23 depicts a fisherman's knot at the distal end of a
medical retrieval assembly according to another illustrative
embodiment of the invention.
[0054] FIG. 24 depicts a fisherman's knot at the distal end of a
medical retrieval assembly according to still another illustrative
embodiment of the invention.
[0055] FIG. 25 depicts a fisherman's knot at the distal end of a
medical retrieval assembly according to yet another illustrative
embodiment of the invention.
[0056] FIG. 26 depicts a surgeon's knot at the distal end of a
medical retrieval assembly according to an illustrative embodiment
of the invention.
[0057] FIGS. 27A-27C depict one series of steps in making the
surgeon's knot in FIG. 25 according to an illustrative embodiment
of the invention.
[0058] FIG. 28 depicts another series of steps in making the
surgeon's knot illustrated in FIG. 25 according to another
illustrative embodiment of the invention.
[0059] FIGS. 29A-29B depict the surgeon's knot at the distal end of
a medical retrieval assembly according to other illustrative
embodiments of the invention.
DESCRIPTION
[0060] The invention is generally related to various types of knots
and methods of making the knots that join filaments together at the
distal end of a medical retrieval device, such as a medical
retrieval basket. Any number of filaments may be used to form the
knots, and additional filaments may be tied in or inserted through
each of the knots. For example, a medical retrieval device
according to the invention includes a retrieval assembly with
filaments knotted together at their distal end. In one embodiment,
the filaments also form legs of the retrieval assembly.
Alternatively, the filaments form the distal end of the retrieval
assembly and the legs are joined to the filaments. The knots
generally fix the position of the filaments at the distal end of
the retrieval assembly and prevent unintended angles from forming
between the legs of the retrieval assembly. The medical retrieval
devices, including the medical retrieval assemblies, have
atraumatic tips, in that the tip does not have any significant
distal protrusion or outward projection that can poke tissue,
pierce tissue, or otherwise cause trauma to tissue or inhibit or
hinder capturing of material from within the body of a patient.
[0061] The following are illustrative embodiments of the invention
in which a medical retrieval device includes a substantially
atraumatic retrieval assembly, for example, a retrieval basket,
including a plurality of legs. The distal end of the retrieval
assembly is formed by knotting together filaments.
[0062] FIG. 1 is a side plan view of a medical retrieval device 7
with a medical retrieval assembly 2 in a fully-extended or open
position according to an illustrative embodiment of the invention.
One feature of this embodiment of the retrieval device 7 for
removing material from a body includes a handle 16, a sheath 14,
and a retrieval assembly, such as basket 2. The handle 16, the
sheath 14, and the retrieval assembly 2 are not shown in their
correct size or proportion to each other. The sheath 14 typically
is much longer than the handle 16 or the retrieval assembly 2 to
allow insertion into a body cavity, canal, or tract. The retrieval
assembly 2 can be made of resilient material, such as metal wires,
forming three or more legs 12.
[0063] With continued reference to FIG. 1, the basket, or retrieval
assembly 2 is the type that is collapsed within the sheath 14 for
entry into the body. The sheath 14 has at least one lumen 15
therein, and it extends from the handle 16 to a distal sheath end
26. An elongated member 18 such as a cable, coil, shaft, guidewire,
hollow tube, or mandril wire 18 extends within the lumen 15 from an
actuating mechanism 4 in the handle 16 to a base 13 of the basket
where the elongated member 18 joins to the basket base 13.
Operation of the actuating mechanism 4 by an operator causes the
basket 2 to move relative to the sheath 14 between a collapsed
position within the sheath 14 as illustrated in FIG. 2, to an
extended position outside of the sheath 14 where the basket 2 is
open and extending beyond the distal end of the sheath 26 as shown
in FIG. 1. When a hollow tube, for example, is the elongated member
used within the sheath, other instruments, such as optical fibers
and/or laser fibers, can be inserted into and extend through a
lumen of the hollow tube for use in conjunction with the retrieval
device.
[0064] Alternatively, the actuating mechanism 4 is operatively
joined to the sheath 14. Thus, the actuating mechanism 4 causes
movement of the sheath 14 to advance the sheath 14 over the
stationary basket 2 and cable 18 combination, to thereby collapse
the basket 2 within the sheath 14, and the actuating mechanism 4
slides the movable sheath 14 back to expose the stationary basket 2
and allow it to open/expand. Alternatively, a second actuating
mechanism (not shown) is joined to the elongated member 18 and the
sheath 14 and the basket 2 are actuated simultaneously. In general,
these types of basket/sheath movement configurations and related
handle mechanisms are known, and are seen in existing product
designs available from, for example, Boston Scientific Corporation
(Natick, Mass.).
[0065] FIG. 2 is a side plan view of the device 7 depicted in FIG.
1 with the retrieval assembly 2 in a collapsed/retracted position
according to an illustrative embodiment of the invention. With the
basket 2 restrained and collapsed within the sheath 14 as shown in
FIG. 2, the sheath 14 is inserted into the body by an operator to a
site in the body where the material to be retrieved is located
(e.g., a stone in the ureter). By placing the retrieval assembly 2
in its unrestrained open/expanded position, as illustrated in FIG.
1, the basket 2 dilates the body tract in which it has been placed
and can be manipulated by the operator to entrap or capture
material within the basket 2. The basket 2 and/or the sheath 14 can
then be moved to cause the legs 12 of the basket 2 to close around
the material and capture it. According to one embodiment, the
captured material may be fragmented by a lithotripsy (not shown) or
crushed by the basket. Alternatively, the captured material is
withdrawn from the body along with the sheath 14 and the basket 2
that is holding the material without fragmenting or crushing the
captured material.
[0066] With continued reference to FIG. 1, in the illustrative
embodiment, the basket 2 features a proximal end portion 24, a
distal end portion 22, and an atraumatic tip 6. The tip 6, in
accordance with the invention, is devoid of protrusions, fasteners,
or outward projections. There is no adhesive necessary at the
basket tip 6 to hold the basket legs 12 together as at least the
basket tip 6 is formed by knotting filaments 100 and 102 together.
However, in another embodiment, the filaments 100, 102 knotted
together at the basket tip 6 are fixed by the application of an
adhesive to the knot.
[0067] FIGS. 3 and 4 depict different embodiments of a retrieval
assembly 2 including a plurality of legs 12. In the illustrated
embodiments, the legs 12 of the retrieval assembly 2 are formed
from the portions of the filaments 100, 102 extending from the knot
at the tip 6. Alternatively, the legs 12 of the retrieval assembly
2 are joined to the filaments 100, 102. The distal end portion 22
of the retrieval assembly 2, thereby, is substantially atraumatic
in that the tip 6 is devoid of outward projections or protrusions
that might cause injury or trauma to tissue and/or that presents an
impediment to contacting the tip 6 of the retrieval assembly 2
directly and intimately with tissue. In one embodiment, heat
treatment, cold-forming, or other shaping processes using a
ball-shaped die, for example, may be performed to shape the legs
into a basket shape.
[0068] All of the following aspects and embodiments further have in
common at least a first filament 100 and a second filament 102
which are knotted together to form the distal tip 6 of the medical
retrieval assembly 2. In one embodiment according to the invention,
referring now to FIG. 3, the filaments 100 and 102 are knotted at
the distal tip 6 of the medical retrieval assembly 2, each filament
100 and 102 forming two legs 12 of the medical retrieval assembly
2. Retrieval assemblies 2 with a different number of odd (i.e.,
three) or even (i.e., four) number of legs 12 may also be
constructed with the filaments 100, 102. A three leg retrieval
assembly 2, for example, illustrated in FIG. 4, can be formed. In
the illustrative embodiment, the three leg retrieval assembly 2 is
formed by trimming away one of the two legs 12 formed by either
filament 100, 102 at the distal tip 6. Alternatively, a three leg
retrieval assembly can be formed by combining two legs together to
form one leg (e.g., by twisting or braiding two or more legs
together) (not shown).
[0069] FIG. 5 depicts a four-leg retrieval assembly 2 including leg
portions 12 formed from the filaments 100, 102 according to an
illustrative embodiment of the invention. In the illustrative
embodiment of the retrieval assembly 2, the first filament 100
includes a first end 104 and a second end 106, and the second
filament 102 includes a first end 108 and a second end 110. As
shown in FIG. 5, in a particular embodiment, the legs 12 of the
retrieval assembly 2 include portions of the filaments 100 and 102
that are secured at their ends 104 and 106, and 102 and 108,
respectively, to the ends of wires 12', 12'', 12''', and 12''''.
The unsecured ends of the wires 12', 12'', 12'', and 12'' '' are
gathered together at the base 13 of the retrieval assembly 2.
[0070] In the illustrative aspects and embodiments for making the
retrieval assembly 2 including a knot at the distal tip 6 according
to the invention herein, the first filament 100 and the second
filament 102 are initially positioned such that the first end 104
of the first filament 100 and the first end 108 of the second
filament 102 correspond to a person's right hand side, and the
second end 106 of the first filament 100 and the second end 110 of
the second filament 102 correspond to a person's left hand side.
This relative positioning is for illustrative purposes only, and
alternate relative positions may be used to form each of the knots.
The knots can be hand tied, as illustrated in the following
embodiments, tied by any automated process, such as a machine, or
tied by a combination of an automated and a manual process.
[0071] According to one embodiment, the filaments 100, 102 can be
made of any biocompatible material, and any combination of
biocompatible materials, including, for example, metals or metal
alloys, such as stainless steel, nickel, and titanium, or cobalt
and chromium alloys. In other embodiments, the filaments 100, 102
can comprise polymers such as, for example, polyester, Nomex.RTM.,
Capton.RTM., and PTFE (Teflon.RTM.). In a particular embodiment,
the filaments 100, 102 are made of a shape memory material, such as
nitinol. The filaments can be round or non-round, flexible,
twisted, braided, roped or solid, and may comprise wires, extruded
polymers, cords, or rope, and single layers, with sheathed multiple
layers, and/or painted filaments.
[0072] FIGS. 6A-6B depict the steps in constructing an embodiment
of an illustrative overhand knot 8 according to an illustrative
embodiment of the invention. According to the illustrative
embodiment, the steps as shown in FIG. 6A include placing the
second end 106 of the first filament 100 across the first end 104
of the first filament 100 to form a loop defining a lumen 101. As
depicted in FIG. 6A, the second end 106 of the first filament 100
is wrapped around the first filament 100 in the direction of the
arrow 109a and passed through the lumen 101 of the loop to exit the
lumen 101 and form the overhand knot 8 illustrated in FIG. 6B.
[0073] Alternatively, the steps of forming an overhand knot 8
include placing the first end 104 of the first filament 100 across
the second end 106 of the first filament 100, winding the second
end 106 and pulling the first end 104 through the lumen 101 of the
loop to exit the overhand knot 8 (not shown). These exemplary
methods for forming an overhand knot 8 are for illustrative
purposes only, and alternate methods of forming the overhand knot 8
may be used for the following embodiments of the invention.
[0074] FIGS. 7A-7B depict exemplary steps in winding one filament
around another filament according to an illustrative embodiment of
the invention. For example, in the illustrative embodiment, the
first filament 100 is placed across the second filament 102. The
second end 106 of the first filament 100, depicted in FIGS. 7A and
7B, is wrapped around the second filament 102 in the direction of
arrow 109a, such that the first filament 100 is wound around the
second filament 102, illustrated in FIG. 7B. This exemplary method
of winding the first filament 100 around the second filament 102 is
for illustration only, and any alternate method of winding one
filament around another filament or around another part of the same
filament may also be used for the following embodiments of the
invention.
[0075] FIG. 8 depicts an end-view of a flipped double overhand knot
10 forming the distal tip 6 of a retrieval assembly 2 according to
an illustrative embodiment of the invention. In the illustrative
embodiment, the filaments 100, 102 of the retrieval assembly 2 exit
the flipped double overhand knot 10 in a substantially symmetric
pattern. However, the filaments 100, 102 may exit the knot in an
asymmetrical pattern (not shown).
[0076] FIGS. 9A-9D depict an exemplary series of steps or stages in
making the flipped double overhand knot 10 illustrated in FIG. 8 at
the distal tip 6 of the retrieval assembly 2 according to an
illustrative embodiment of the invention. In the exemplary
embodiment depicted in FIG. 9A, the first step of the flipped
double overhand method of forming the distal tip 6 of the retrieval
assembly 2 includes laying the second filament 102 across and
substantially perpendicular to the first filament 100. In the next
step, shown in FIG. 9B, the second end 106 of the first filament
100 is placed across the first end 104 of the first filament 100
and a first single overhand knot 8' is tied in the first filament
100. The second filament 102 is secured thereby to the first
filament 100. FIG. 9C depicts the next step of the flipped double
overhand method, in which the second end 110 of the second filament
102 is placed across the first end 108 of the second filament 102
and a second single overhand knot 8'' is tied in the second
filament 102. The first single overhand knot 8' is thereby captured
or linked to the second single overhand knot 8'' to form the distal
tip 6 of the retrieval assembly 2. The first end 108 and second end
110 of the second filament 102 can be pulled in the direction of
the arrows 109a, 109b, and the first end 104 and second 106 of the
first filament 100 can be pulled in the direction of the arrows
109c and 109d, indicated FIG. 9D, such that the first end 108 of
the second filament 102 is substantially perpendicular to the first
end 104 of the first filament 100, and the second end 110 of the
second filament 102 is substantially perpendicular to the second
end 106 of the first filament 100. In a particular embodiment of
the retrieval assembly 2, an end of filaments 100 and 102 extending
from the distal tip 6 can form at least a portion of a leg 12 as
shown in FIG. 5.
[0077] Alternative methods (not shown) may also be used to form the
distal tip 6 including the flipped double overhand knot 10. For
example, the flipped double overhand knot 10 can be formed by
laying the second filament 102 across and substantially
perpendicular to the first filament 100. The first end 104 of the
first filament 100 is then placed across the second end 106 of the
first filament 100 and a first overhand knot 8' is tied around the
second filament 102. The filaments 100, 102 are initially
positioned such that the portion of the first overhand knot 8' in
which the first end 104 of the first filament 100 crosses the
second end 106 of the first filament 100 is facing upward from a
flat planar surface. The filaments 100 and 102 can then be turned
over and positioned such that the portion of the first overhand
knot 8' in which the first end 104 of the first filament 100
crosses the second end 106 of the first filament 100 is facing
downward toward the flat planar surface. The second end 110 of the
second filament 102 is then placed across the first end 108 of the
second filament 102 and a second overhand knot 8'' is tied around
the first filament 100. The first single overhand knot 8' is
thereby captured or linked to the second single overhand knot 8''
to form the distal tip 6 of the retrieval assembly 2.
[0078] FIG. 10 depicts an end-view of a carrick bend knot at the
distal end of a medical retrieval assembly according to an
illustrative embodiment of the invention. In the illustrative
embodiment, the ends 104, 106, 108 and 110 of the filaments 100,
102 are arranged in a symmetric, radial pattern. Alternatively, the
filaments 100, 102 are arranged in an asymmetric pattern, or in
some other symmetric pattern (not shown). FIGS. 11A-11C illustrate
an exemplary series of steps or stages of the method used to form
the carrick bend knot 20 at the distal tip 6 of the retrieval
assembly 2.
[0079] FIGS. 11A-11C depict the steps in making the carrick bend
knot illustrated in FIG. 10 according to an illustrative embodiment
of the invention. As shown in the illustrative embodiment in FIG.
11A, the first filament 100 is bent in the first step of the method
such that the second end 106 of the first filament 100 crosses the
first end 104 of the first filament 100 to form a first loop 200
defining a lumen 201. Next, the first loop 200 is placed on top of
the second filament 102. The second filament 102 is then bent in
the direction indicated by the arrow 109a such that the first end
108 of the second filament 102 crosses the second end 106 of the
first filament 100 and is placed under the first end 104 of the
first filament 100 to form a second loop 202. In the illustrative
embodiment depicted in FIG. 11B, the first end 108 of the second
filament 102 is passed over the first filament 100, through the
lumen 201 of the first loop 200, under the second filament 102, and
then back through the lumen 201 of the first loop 200 as indicated
by arrow 109a to exit the lumen 201 and form the carrick bend knot
20 of the distal tip 6 of the retrieval assembly 2, as depicted in
FIG. 11C. Pulling the ends 104 and 106 of the first filament 100
and the ends 108 and 110 of the second filament 102 in the
directions indicated by the arrows 109a, 109b, 109c, and 109d
positions the first loop 200 substantially adjacent to the second
loop 202 and secures the first filament 100 to the second filament
102. In a particular embodiment of the retrieval assembly, an end
of filaments 100 and 102 extending from the knot 20 at the distal
tip 6 can form at least a portion of a basket leg 12 as shown in
FIG. 5.
[0080] FIG. 12 depicts a carrick bend knot 20 at the distal end 6
of the retrieval assembly 2 according to an illustrative embodiment
of the invention. A flat radial configuration carrick bend knot 20
can be made when the carrick bend knot 20 is tightened by pulling
each of the first end 104 of the first filament 100 and the first
end 108 of the second filament 102, and pulling the second end 106
of the first filament 100 and the second end 110 of the second
filament 102 until adjacent legs 12 exit the carrick bend knot 20
in substantially perpendicular paths.
[0081] FIG. 13 depicts a knot known as a water or webbing knot 30,
herein referred to as the "water/webbing" knot 30, at the distal
end 6 of the retrieval assembly 2 according to an illustrative
embodiment of the invention. FIGS. 14A-14C depict an exemplary
series of steps of a method of making a water/webbing knot 30 to
form the distal tip 6 of the medical retrieval assembly 2.
Referring to FIG. 14A, the first step in forming the water/webbing
knot 30 at the distal end 6 of the retrieval assembly 2 includes
grouping in parallel at least a first filament 100 and a second
filament 102. As shown in FIG. 14B, a single overhand knot 8 is
tied in the filaments 100 and 102 to form the distal tip 6 of the
retrieval assembly 2. The knot 30, depicted in FIG. 14C, can be
tightened by pulling the first end 104 of the first filament 100
and the first end 108 of the second filament 102 in the direction
indicated by arrow 109a, and the second end 106 of the first
filament 100 and the second end 110 of the second filament 102 in
the direction indicated by arrow 109b. In a particular embodiment
of the retrieval assembly 2, an end of the filaments 100 and 102
extending from the knot 30 of distal tip 6 can form at least a
portion of a basket leg 12 as shown in FIG. 5.
[0082] In other embodiments of the distal tip 6 of the retrieval
assembly 2, more than two filaments are used to construct the
atraumatic distal tip 6 including the water/webbing knot 30. In the
illustrative embodiment of FIG. 15A, the water/webbing knot 30 is
tied with three filaments 100, 102 and 103. The ends of the three
filaments 100, 102 and 103 that extend from the water/webbing knot
30 at the distal tip 6 can be used to form all or a portion of the
legs 12 of a retrieval assembly 2, including six legs 12 in a
manner similar to the legs 12 of the retrieval assembly 2 including
four legs 12, illustrated in FIG. 5. Alternatively, as depicted in
the illustrative embodiment in FIG. 15B, additional filaments 103
can be inserted through the water/webbing knot 30 to form one or
more additional legs 12', 12'' of the medical retrieval assembly
2.
[0083] FIG. 16 depicts a barrel knot 40 at the distal tip 6 of a
medical retrieval assembly 2 according to an illustrative
embodiment of the invention. FIGS. 17A-17C illustrate one exemplary
series of steps or stages of the method for forming the barrel knot
40 of the distal tip 6 of the retrieval assembly 2. As shown in
FIG. 17A, a first filament 100 is laid parallel to and grouped with
a second filament 102. As depicted in FIG. 17B, the filaments 100
and 102 are coiled together as indicated by the arrow 109a. The
coiled filaments 100, 102 form two concentric loops 105 and 107
depicted in FIG. 17C. Each loop 105 and 107 defines a lumen 105a,
107a, respectively. An overhand knot, illustrated in FIG. 17C, is
tied through the lumens 105a, 107a of the loops 105 and 107,
respectively, in the direction indicated by the arrow 109a to
secure the filaments 100 and 102 in the knot 40 and form the distal
tip 6 of the retrieval assembly 2. In a particular embodiment of
the retrieval assembly 2, an end of the filaments 100 and 102
extending from the barrel knot 40 at the distal tip 6 can form at
least a portion of a leg 12 as shown in FIG. 5.
[0084] FIGS. 18A-18C illustrate an alternate exemplary series of
steps or stages of the method for forming the barrel knot 40 of the
distal tip 6 of the retrieval assembly 2. Referring to FIG. 18A,
the first step in forming the barrel knot 40 at the distal end 6 of
the retrieval assembly 2 includes grouping in parallel at least a
first filament 100 and a second filament 102. As shown in FIG. 18B,
the filaments 100 and 102 are bent to form a loop 209 defining a
lumen 210 and the ends of the filaments 106 and 110 cross over and
are wound around a portion of the grouped filaments 100 and 102 and
through the lumen 210 of the loop 209 two or more times. As shown
in FIG. 18C, the barrel knot 40 formed by this method can be
tightened by pulling the ends of the filaments 108 and 104 in the
direction indicated by arrow 109a and/or by pulling the ends of the
filaments 106 and 110 in the direction indicated by arrow 109b.
[0085] In an alternative embodiment of the distal tip 6 of the
retrieval assembly 2, more than two filaments are used to form the
barrel knot 40. For example, FIG. 19 illustrates three filaments
knotted in a barrel knot 40 to form the distal tip 6 of the medical
retrieval assembly 2. According to the illustrative embodiment,
three filaments 100, 102 and 103 are grouped together. The barrel
knot 40 is tied with the three filaments 100, 102 and 103 at the
distal tip 6 of the retrieval assembly 2. This embodiment of the
barrel knot 40 features six legs 12 extending from the distal tip
6. In yet other embodiments, such as that illustrated in FIG. 20,
the distal tip 6 of the medical retrieval assembly 2 is constructed
by coiling the filaments 100 and 102 to form more than two loops,
for example three loops, each loop defining a lumen. An overhand
knot is tied with the filaments 100 and 102 through the lumens of
the three loops to form the three-loop barrel knot 40 illustrated
in FIG. 20.
[0086] FIG. 21 depicts a fisherman's knot 50 at the distal end 6 of
a retrieval assembly 2 according to an illustrative embodiment of
the invention. FIGS. 22A and 22B illustrate an exemplary series of
steps or stages of the method to form the fisherman's knot 50 at
the distal tip of the retrieval assembly 2. As shown in the
illustrative embodiment of FIG. 22A, a first overhand knot 8' is
tied in the first filament 100 onto a first position 802 of the
second filament 102. The first position 802 is located anywhere
along the length of the second filament 102. As shown in the
illustrative embodiment of FIG. 22B, a second overhand knot 8'' is
tied in the second filament 102 onto a second position 804 of the
first filament 100 to form the distal tip 6 of the retrieval
assembly 2. The second position 804 is located at a position on the
first filament 100 that is not knotted. The fisherman's knot 50 can
be tightened by pulling the first end 104 of the first filament
100, the first end 108 of the second filament 102, the second end
106 of the first filament 100, and the second end 110 of the second
filament 102, in the directions indicated by the arrows 109a, 109b,
109c, 109d, respectively. In a particular embodiment of the
retrieval assembly 2, an end of the filaments 100 and 102 extending
from the fisherman's knot 50 at the distal tip 6 can form at least
a portion of a leg 12 as shown in FIG. 5.
[0087] FIG. 23 depicts a modified fisherman's knot 50 at the distal
tip 6 of a retrieval assembly 2 according to an illustrative
embodiment of the invention. According to an exemplary embodiment
of the invention, the modified fisherman's knot 50 at the distal
tip 6 of the medical retrieval assembly 2 is constructed by the
barrel knot method, described above and shown in FIGS. 18A-18C. For
example, to make the modified fisherman's knot 50 depicted in FIG.
23, the barrel knot method is repeated at least twice with the
filaments 100, 102 to create at least two independent barrel knots
40 along the filaments 100 and 102.
[0088] In the illustrative embodiment shown in FIG. 23, the
individual barrel knots 40 are spaced apart, for example, by a
center portion 800 of the fisherman's knot 50.
[0089] FIG. 24 depicts a fisherman's knot 50 according to another
illustrative embodiment of the invention. In the illustrative
embodiment, the fisherman's knot 50 includes additional legs 12',
12'', which are constructed by inserting one or more filaments 103
through the center portion 800. Alternatively, in the illustrative
embodiment shown in FIG. 25, the distal tip 6 features a
fisherman's knot 50 in which the independent barrel knots 40 are
placed adjacent to each other.
[0090] In further embodiments, the distal tip 6 includes a
fisherman's knot 50 formed from more than two filaments. For
example, three filaments may be used to form the fisherman's knot
50 by adding a third overhand knot in the third filament in a
manner similar to the first and second overhand knots 8', 8''
described above with respect to the fisherman's knot 50. In this
embodiment, the two ends of each of the three filaments may form
six retrieval assembly legs (not shown).
[0091] FIG. 26 depicts a surgeon's knot 60 at the distal tip 6 of
the retrieval assembly 2 according to an illustrative embodiment of
the invention. FIGS. 27A-27C illustrate an exemplary series of
stages or steps of the first method of forming the surgeon's knot
60 at the distal tip 6 of the retrieval assembly 2. As shown in the
illustrative embodiment of FIG. 27A, the first filament 100 is bent
to form a first loop 200 defining a lumen 205. The first loop 200
is laid on top of and substantially perpendicular to the second
filament 102. The first end 108 and the second end 110 of the
second filament 102 are placed through the lumen 205 of the first
loop 200 in the direction indicated by the arrows 109a, 109b in
FIG. 27A to form a second loop 202 defining a lumen 207, depicted
in FIG. 27B. The first end 106 of the second filament 102 is wound
through the lumen 205 of the first loop 200 and around the first
filament 102 in the direction as indicated by arrow 109a. The
second end 106 of the first filament 100 is wound through the lumen
207 of the second loop 202 and around the second filament 102 in
the direction indicated by arrow 109b.
[0092] FIG. 27C depicts a surgeon's knot 60 at the distal tip 6 of
a retrieval assembly 2 according to another illustrative embodiment
of the invention. In the illustrative embodiment, the first
surgeon's knot method includes winding the first end 108 of the
second filament 102 through the lumen 205 of the first loop 200 and
around the first filament 100, and winding the second end 106 of
the first filament 100 through the lumen 207 of the second loop 202
and around the second filament 102, in the directions indicated by
the arrows 109a, 109b in FIG. 27C. In a particular embodiment
according to the invention, an end of the filaments 100 and 102
extending from the surgeon's knot 60 at the distal tip 6 can form
at least a portion of a leg 12 as shown in FIG. 5.
[0093] FIG. 28 depicts a surgeon's knot 60 at the distal tip 6 of a
medical retrieval assembly 2 according to an illustrative
embodiment of the invention. The surgeon's knot 60 is constructed
by the steps set forth in FIG. 28, herein referred to as the second
surgeon's knot method. The second surgeon's knot method includes
winding a first filament 100 around a second filament 102 at least
three times and tying an overhand knot using the first end 108 of
the second filament 102 and the second end 106 of the first
filament 100, in the direction indicated by the arrows 109a, 109b
in FIG. 28.
[0094] Regardless of whether the first sutgeon's knot method or the
second surgeon's knot method is used to construct the distal tip 6
of the medical retrieval assembly 2, the first filament 100 and the
second filament 102 can be wound around each other more than three
times, for example, four times as illustrated in FIG. 29A, and six
times as illustrated in FIG. 29B.
[0095] In other embodiments, a medical retrieval device 7 can have
a retrieval assembly 2 constructed from the same or a combination
of knots according to the invention. Alternatively, the knots and
methods of the invention can be utilized for any device which
requires the joining of filaments.
[0096] In another aspect, the invention relates to a method for
retrieving material from a body, such as a body tract or body
canal. Material (e.g., biological or foreign) can be retrieved from
a body by using a retrieval assembly 2 according to the invention
with an atraumatic tip that is formed by knotting together
filaments 100, 102 at the distal end 6 of the retrieval assembly 2.
The retrieval assembly 2 has a distal tip 6 that is atraumatic,
thus allowing the capture of material that is located in pockets
such as the renal calyx or other difficult-to-access areas within
the body. Because the distal tip 6 is atraumatic, the retrieval
assembly 2 can make intimate contact with the surface of tissue,
even the walls or lining of a pocket-type area, and allow the
retrieval of stones or other materials that are unrecoverable with
conventional tipped retrieval assemblies that can cause tissue
trauma and are limited in how close the retrieval assembly can get
to the tissue because of the existence of the protruding tip.
[0097] A method for retrieving material from a body includes
inserting a retrieval device 7 according to the invention into the
body, moving the retrieval assembly 2 into the unrestrained
position by withdrawing the sheath 14 from the retrieval assembly 2
with the retrieval assembly 2 in a stationary position, or by
extending the retrieval assembly 2 outside the sheath 14 with the
sheath 14 in a stationary position. The retrieval assembly 2 is
maneuvered via the actuator 4 on the handle 16 (which is located
outside of the body) of the retrieval device 7 until the material
(e.g., stone) is entrapped within the three-dimensional retrieval
assembly 2, and the material is captured within the retrieval
assembly 2 by moving the retrieval assembly 2 relative to the
sheath 14 by any of the above disclosed mechanisms to close the
legs 12 of the retrieval assembly 2 around the material. With the
material held by the retrieval assembly 2, the medical retrieval
device 7, including the retrieval assembly 2, can be withdrawn from
the body to remove the material from the body. In one embodiment of
the method, before the retrieval assembly 2 is withdrawn from the
body with the captured material, the material can be broken apart
by, for example, laser energy or mechanical lithotripsy. Mechanisms
for breaking up the material before its removal from the body can
be part of the retrieval device 7 or can be separate tools/devices
that are also inserted into the body and utilized at the
appropriate time to break apart the material. The materials that
can be captured with retrieval assemblies 2 according to the
invention include tumors, for example, a polyp, or a stone, such as
a kidney stone, a ureteral stone, a urinary bladder stone, a gall
bladder stone, or a stone within the biliary tree.
[0098] Variations, modifications, and other implementations of what
is described herein will occur to those of ordinary skill without
departing from the spirit and the scope of the invention.
Accordingly, the invention is not to be limited only to the
preceding illustrative description.
* * * * *