U.S. patent application number 10/171425 was filed with the patent office on 2002-10-17 for wire connector structures for tubular grafts.
Invention is credited to Berg, Todd A., Hindrichs, Paul J..
Application Number | 20020151913 10/171425 |
Document ID | / |
Family ID | 25484921 |
Filed Date | 2002-10-17 |
United States Patent
Application |
20020151913 |
Kind Code |
A1 |
Berg, Todd A. ; et
al. |
October 17, 2002 |
Wire connector structures for tubular grafts
Abstract
Connector structures are provided for attaching elongated
flexible tubular grafts to the body organ tubing of a patient. The
connector structures are formed from wire. A first set of connector
wires may be disposed around the periphery of one end of an
elongated flexible tubular graft. A second set can be disposed
around the periphery of the elongated flexible tubular graft spaced
sufficiently from the first set of connector wires to define a gap.
The portion of body organ tubing to which the elongated flexible
tubular graft is to be attached is received in the gap and engaged
by the first and second sets of connector wires. The wires may be
formed in the shape of loops. If desired, hooks may be provided on
the ends of the wires. The wires may be curved to accommodate
attachment of the graft to tubular body organ tubing. The wires may
also be formed in annular shapes. The connector structures may be
formed as stand-alone ring-shaped connectors. Obliquely-angled
connections between grafts and body organ tubing may be made using
the connector structures.
Inventors: |
Berg, Todd A.; (Plymouth,
MN) ; Hindrichs, Paul J.; (Plymouth, MN) |
Correspondence
Address: |
FISH & NEAVE
1251 AVENUE OF THE AMERICAS
50TH FLOOR
NEW YORK
NY
10020-1105
US
|
Family ID: |
25484921 |
Appl. No.: |
10/171425 |
Filed: |
June 12, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10171425 |
Jun 12, 2002 |
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09505540 |
Feb 17, 2000 |
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09505540 |
Feb 17, 2000 |
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08946742 |
Oct 9, 1997 |
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6074416 |
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Current U.S.
Class: |
606/153 ;
623/1.36 |
Current CPC
Class: |
A61F 2220/0016 20130101;
A61F 2002/075 20130101; A61F 2220/005 20130101; A61F 2220/0075
20130101; A61F 2/90 20130101; A61F 2/07 20130101; A61F 2/064
20130101; A61F 2220/0008 20130101; A61F 2/848 20130101; A61F
2220/0058 20130101 |
Class at
Publication: |
606/153 ;
623/1.36 |
International
Class: |
A61B 017/08 |
Claims
The invention claimed is:
1. A method of forming spike tips of an anastomotic connector, into
hooks for engaging blood vessels, comprising: providing an
anastomosis connector having a plurality of straight spikes having
tips; first bending said tips at a first angle, using a first
mandrel; and second bending a furtherly distal portion of said tips
using a second mandrel, to form a hook shape of said tips.
2. A method according to claim 1, comprising mounting a graft on
said spikes of said connector prior to said first bending.
3. A method of heat-treating an anastomosis connector, comprising:
fitting a cut connector into a mold; fixing said mold to bend both
forward and backwards spikes of said connector into a desired
configuration; and heat-treating said fixed connector, thereby
training it to said configuration.
4. A connector adapter to be distorted for oblique connections,
comprising: a plurality of interconnected segments, at least some
of said segments including a forward spike or a backward spike; and
a plurality of distortable portions defined between said segments,
wherein said portions are adapted to support a distortion from a
straight anastomosis to an oblique anastomosis.
5. A connector according to claim 4, wherein said distortable
portions comprise at least one ring.
6. A connector according to claim 4, wherein said distortable
portions are designated in a ring that interconnects said
segments.
7. A connector according to claim 4, wherein said distortable
portions are annealed.
8. A connector according to claim 4, wherein said spikes are self
extending.
9. A connector according to claim 4, wherein said distortable
portions are plastically deformable.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/505,540, filed Feb. 17, 2000, which is a
continuation of U.S. patent application Ser. No. 08/946,742, filed
Oct. 9, 1997 (now U.S. Pat. No. 6,074,416). Both of these prior
applications are hereby incorporated by reference herein in their
entireties.
BACKGROUND OF THE INVENTION
[0002] This invention relates to tubular graft structures for
replacing or supplementing a patient's natural body organ tubing.
More particularly, the invention relates to structures for
connecting the ends of such tubular graft structures to body organ
tubing.
[0003] A patient's weakened or diseased body organ tubing can often
be repaired by replacing or supplementing the patient's existing
natural body organ tubing with an artificial graft structure. One
suitable type of artificial graft structure uses a tubular nitinol
mesh frame covered with a silicone coating, as described in
Goldsteen et al. U.S. Pat. No. 5,976,178. Such grafts are highly
flexible, so they recover their shape after being stretched.
Accordingly, a graft of this type may be stretched axially to
reduce its radial dimension and then installed in a patient
intraluminally (e.g., through an existing vein or artery). Once
delivered to the proper location within the patient, the axially
stretched graft may be released, whereupon it expands to regain its
original shape.
[0004] In addition, flexible artificial grafts may be made
distensible like natural body organ tubing to help reduce clot
formation when used in vascular applications. Flexible artificial
grafts may also be made biocompatible by adjusting their porosity
and the composition of their coatings.
[0005] Various connector structures may be used to attach flexible
artificial grafts to a patient's body organ tubing. For example, a
graft may be surgically attached to a patient's body organ tubing
with sutures. To install a graft intraluminally, a pronged ring may
be expanded from within the end of the graft, thereby piercing the
graft and attaching it to surrounding body organ tubing. Barbed
flaps and wire hooks may also be used to attach grafts to body
organ tubing. Connector structures of these types and other
suitable connector structures are described in the above-mentioned
Goldsteen et al. U.S. Pat. No. 5,976,178 and in Bachinski et al.
U.S. Pat. No. 6,036,702.
[0006] Although connector structures of these types have various
useful features, it would be desirable if connector structures with
other features were available.
[0007] It is therefore an object of the present invention to
provide improved connector structures for attaching grafts to a
patient's body organ tubing.
SUMMARY OF THE INVENTION
[0008] This and other objects of the invention are accomplished in
accordance with the principles of the present invention by
providing connectors for attaching flexible graft structures to
body organ tubing. The connectors may be entirely or nearly
entirely from wire. The flexibility of the wire allows the
connectors to be radially contracted during intraluminal insertion
into a patient and subsequently radially expanded at the
installation site. In addition, the flexibility of the structures
makes it possible to match the compliance or flexibility
characteristics of the connector with the compliance of the body
organ tubing and artificial graft structures at the attachment
site.
[0009] To form a secure connection between the graft and the body
organ tubing, the wire for the connectors can be arranged in two
opposing groups of wires near the end of the graft. The wires in
the first of the two groups are arranged about the periphery of the
end of the graft. The wires in the second group are spaced by a gap
from the wires in the first group along the longitudinal axis of
the graft. The body organ tubing is held in the gap by the two
opposing groups of wires.
[0010] The wires in the connectors may be loops or may be
individual wires. The wires may also be curved to accommodate
connections between grafts and natural body organ tubing that is
tubular in shape.
[0011] If desired, the connectors may be used to form
non-right-angle connections between grafts and body organ
tubing.
[0012] The connectors may also be annular in shape. Such annular
connectors may be formed by molding a heat-sensitive wire mesh over
an appropriate mandrel and heat treating the wire.
[0013] Further features of the invention, its nature and various
advantages will be more apparent from the accompanying drawings and
the following detailed description of the preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a partially cut-away perspective view of an
artificial graft structure attached to two sections of body organ
tubing with illustrative connectors in accordance with the present
invention.
[0015] FIG. 2 is a partly-sectional side view of an illustrative
graft having wire connectors that are engaging a portion of body
organ tubing in accordance with the present invention.
[0016] FIG. 3 is a side view of an illustrative graft with wire
connectors in accordance with the present invention.
[0017] FIGS. 4a and 4b are side views of portions of illustrative
grafts having wire connectors that are interwoven and attached to
the wire mesh of a graft in accordance with the present
invention.
[0018] FIG. 5 is a side view of a portion of an illustrative graft
having a wire connector attached at points of the mesh other than
the wire intersection points of the mesh in accordance with the
present invention.
[0019] FIGS. 6a, 6b, and 6c are perspective views of illustrative
hook structures for use with the connectors of the present
invention.
[0020] FIG. 7a is a perspective view of an illustrative flattened
portion of a wire connector in accordance with the present
invention.
[0021] FIG. 7b is a perspective view of an illustrative flattened
and hooked portion of a wire connector in accordance with the
present invention.
[0022] FIG. 8 is a perspective view of an illustrative webbed wire
connector structure in accordance with the present invention.
[0023] FIG. 9 is a side view of an illustrative graft with looped
wire connectors in accordance with the present invention.
[0024] FIGS. 10a, 10b, and 10c are side views of a graft with
illustrative connector structures in accordance with the present
invention in which the use of a sheath to attach the graft to a
portion of body organ tubing is shown.
[0025] FIG. 11 is an end sectional view of an illustrative
connector arrangement in accordance with the present invention in
which the connector wires are curved to accommodate the curvature
of the tubular body organ tubing to which the graft is
connected.
[0026] FIG. 12 is a sectional view taken along the line 12-12 in
FIG. 11.
[0027] FIG. 13 is an end sectional view of another illustrative
connector arrangement in accordance with the present invention in
which the connector wires are curved to accommodate the curvature
of the tubular body organ tubing to which the graft is
connected.
[0028] FIG. 14 is a sectional view taken along the line 14-14 in
FIG. 13.
[0029] FIG. 15 is an end sectional view of still another
illustrative connector arrangement in accordance with the present
invention in which the connector wires are curved to accommodate
the curvature of the tubular body organ tubing to which the graft
is connected.
[0030] FIG. 16 is a sectional view taken along the line 16-16 in
FIG. 15.
[0031] FIGS. 17a and 17b are side views of illustrative
annularly-shaped wire connectors in accordance with the present
invention.
[0032] FIGS. 18a and 18b are side views of illustrative steps
involved in installing wire connector structures such as the
connector structures of FIGS. 17a and 17b.
[0033] FIGS. 19a and 19b are side and top views, respectively, of
an illustrative right-angle connection between a graft and a length
of body organ tubing in accordance with the present invention.
[0034] FIGS. 20a and 20b are side and top views, respectively, of
an illustrative non-right-angle connection between a graft and a
length of body organ tubing in accordance with the present
invention.
[0035] FIG. 21 is a perspective view of a non-right-angled end of a
graft having illustrative connectors in accordance with the present
invention.
[0036] FIG. 22 is a perspective view of the graft of FIG. 21
connected to a length of body organ tubing.
[0037] FIG. 23 is a perspective view of a length of natural body
tubing to which two illustrative ring-shaped wire connector
structures have been attached in accordance with the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] A flexible artificial graft 30 connected to body organ
tubing 32 with illustrative wire connectors 34 in accordance with
the present invention is shown in FIG. 1. Graft 30 may be a
structure formed from a flexible coating 36 covering a frame 38.
The preferred materials for forming frame 38 of graft 30 are
metals, although polymeric materials may also be used. The
presently most preferred material is a braid of nitinol wire. Wire
connectors 34 are preferably formed from the same type of flexible
material as frame 38 (e.g., nitinol wire). Nitinol wire is heat
sensitive, so connectors 34 of various shapes may be formed by
bending the wire of a given connector into a desired shape and
applying a heat treatment to set the wire in that shape.
[0039] Coating 36 is preferably an elastic biocompatible material
such as silicone, which fills the apertures formed by the wires in
frame 38. Other materials that may be used for coating 36 include
polymeric materials such as stretchable urethane, stretchable
polytetrafluoroethylene (PTFE), natural rubber, and the like.
[0040] If desired, coating 36 can be formed with microscopic pores
to help improve biocompatibility. A preferred method of providing a
desired porosity is to make coating 36 from an elastic material
that is mixed with particles of a material that can be removed
(e.g., by vaporization) after coating 36 has been applied to frame
38. When the particles are removed, voids are left in coating 36
that give it porosity.
[0041] Graft 30 may be provided with additional coatings such as
medicated coatings, hydrophilic coatings, smoothing coatings,
collagen coatings, human cell seeding coatings, etc., as described
in the above-mentioned Goldsteen et al. U.S. Pat. No. 5,976,178,
which is hereby incorporated by reference herein in its entirety.
The above-described preferred porosity of coating 36 may help graft
30 to retain these coatings.
[0042] In the illustrative example of FIG. 1, graft 30 has been
used to form a connection between two sections of body organ tubing
32. Graft 30 may be used to connect portions of body organ tubing
of any suitable shape. As defined herein, the term "body organ
tubing" generally refers to elongated fluid-containing body organ
tissues such as blood vessels and the like and to similar but less
elongated body organ tissue structures such as portions of the
heart wall. Body organ tubing 32 may be vascular tubing or any
other type of body organ tubing.
[0043] In accordance with the present invention, connector
structures such as wire connectors 34 are used to attach the ends
of graft 30 to body organ tubing 32. The illustrative connectors 34
of FIG. 1 are relatively short pieces of protruding wire that are
welded to frame 38.
[0044] As shown in FIG. 2, portions of the wire forming connectors
34 protrude on both sides of the body organ tubing 32 to which
graft 30 is attached. In particular, connector wires 40 protrude on
one side of body organ tubing wall 42 (inside tubing 32) and
connector wires 44 protrude on the other side of body organ tubing
wall 42 (outside tubing 32). This arrangement holds graft 30 firmly
in place at the attachment site.
[0045] Graft 30 is depicted as a bare metal mesh in FIG. 2 and many
of the other FIGS. to show the details of construction of the
connector structures. However, graft 30 preferably has a coating
such as coating 36 of FIG. 1.
[0046] As shown in FIG. 2, wires 40 and 44 in each connector
structure 34 are preferably the bent ends of a single piece of
wire. If desired, however, connector wires 40 and 44 may be formed
from individual wire segments.
[0047] Wires 40 and 44 may be approximately 0.10.125 inches in
length and may be axially spaced to form a gap approximately 0.1
inches wide. For example, wire 40 may be approximately 0.1 inches
in length and wire 44 may be approximately 0.125 inches in length.
Connectors 34 may be formed from 0.005-0.010 inch diameter round
nitinol wire. These dimensions are merely illustrative. Wire of any
suitable length and diameter may be used. If desired, the wire in
connectors 34 may be coated with a polymeric coating such as
polytetrafluoroethylene (PTFE), to reduce abrasion of body organ
tubing 32.
[0048] As shown in FIG. 3, connectors 34 are formed around the
entire periphery of end 46 of graft 30. The number of connectors 34
that are used depends on the type of graft connection being formed,
the difficulty and expense of providing additional connectors 34,
and the particular type of connectors 34 that are used. Although
connectors 34 are shown at the end of a portion of a graft 30 in
FIGS. 1-3, connectors 34 may be placed at an intermediate location
along the length of graft 30 if desired. When connectors 34 are
used to attach graft 30 to body organ tubing, a portion of the body
organ tubing is engaged in gap 33 by connectors 34.
[0049] Connectors 34 may be attached to graft 30 using any suitable
mounting technique. For example, each connector structure 34 may be
interwoven with the pattern of mesh 38 and welded at pic points or
wire intersections 48, as shown in FIG. 4a. In the illustrative
interweaving pattern shown in FIG. 4a, the wire of connector 34 is
first placed under the wires at a wire intersection 48 of frame 38,
then over an adjacent wire intersection 48, then under the next
adjacent wire intersection 48, then over the next adjacent wire
intersection 48.
[0050] Another illustrative interweaving pattern and mounting
technique is shown in FIG. 4b. In FIG. 4b, each connector 34 is
glued to frame 38 at a wire intersection 48. The wire of connector
34 is first placed under a wire intersection 48, then under an
adjacent wire intersection 48, then over the next adjacent wire
intersection 48, then over the next wire intersection 48. Any
suitable number of interweaving points and attachment points may be
used. The number of times the wire of connector 34 is interwoven
with the wire of frame 38 is partly determined by the pic count of
frame 38 (i.e., the number of wire intersection points in the mesh
of frame 38 per unit length along a straight axial line). The wire
of each connector 34 is attached to frame 38 sufficiently often to
ensure that connectors 34 are firmly attached to graft 30. Only a
few interweaving and attachment points are shown in FIGS. 4a and 4b
to avoid overcomplicating the drawings.
[0051] As shown in FIG. 5, connectors 34 may be attached (e.g.,
welded, glued, or otherwise suitably fastened) at attachment points
50 that do not coincide with wire intersections 48.
[0052] FIG. 5 also shows how the ends of wires 40 and 44 of each
connector 34 may have hooks 52 that permit connectors 34 to grip
body organ tubing 32 (FIG. 1). By gripping body organ tubing 32,
hooks 52 facilitate the formation of a firm connection between
graft 30 and body organ tubing 32.
[0053] Hooks 52 may be formed by bending the ends of connectors 34,
by attaching separate hook members or by any other suitable
technique. A hook 52a formed by bending the end of a connector 34
is shown in FIG. 6a. A hook 52b formed by attaching a length of
wire to the end of a connector 34 is shown in FIG. 6b. FIG. 6c
shows a hook 52c formed by attaching a triangular point to the end
of a connector 34. Any portion of a connector that should penetrate
body tissue may be barbed so that the connector resists removal
from tissue that it has penetrated.
[0054] In order to reduce tissue abrasion due to the wires of
connectors 34 rubbing against body organ tubing 32 (FIG. 1), at
least the ends of the wires 40 and 44 of connectors 34 can be
flattened rather than being perfectly round, as shown in FIG. 7a.
If initially round, wires 40 and 44 (shown as wire 40/44 in FIG.
7a) may be flattened at their ends using any suitable
technique.
[0055] As shown in FIG. 7b, flattened wire 40/44 of connector 34
may be provided with a hook 52d by bending the tip of wire
40/44.
[0056] As shown in FIG. 8, wires 40 and 44 of connectors 34 may be
provided with webs of elastic material (e.g., silicone), such as
webs 54 and 56. Webs 54 and 56 help to shield body organ tubing 32
(FIG. 1) from the potentially abrasive effects of contact with
wires 40 and 44 and help to hold graft 30 to the body organ tubing
32 engaged in gap 33.
[0057] If desired, connectors 34 may be formed from wire loops,
such as wire loops 58 and 60 shown in FIG. 9. Wire loops 58 and 60
may be formed by bending over extended integrally-formed portions
of the wire mesh of graft 30, as illustrated by loop 58a.
Alternatively, wire loops 58 and 60 may be formed by attaching wire
segments to frame 38 (e.g., by welding, gluing, or other suitable
attachment technique) at attachment points 62. If frame 38 is
formed from a braided wire having, e.g., 64 strands, particularly
suitable configurations for the connector structures of graft 30
may have 32, 16, 8, or 4 loops 58 and 60. When graft 30 of FIG. 9
is connected to body organ tubing, a portion of body organ tubing
is engaged in gap 33.
[0058] One suitable technique for installing a graft 30 with
connectors 34 is shown in FIGS. 10a, 10b, and loc. Prior to
installation, graft 30 is loaded into sheath 68, thereby radially
compressing wires 40 and 44, as shown in FIG. 10a. If desired,
graft 30 may be delivered to an installation site in a patient
intraluminally. At the installation site, graft 30 is inserted into
a hole 64 that has been formed in body organ tubing wall 66, as
shown in FIG. 10a. During insertion, sheath 68 holds wires 40 and
44 of connectors 34 radially inward and out of the way, so that
graft 30 may be advanced through hole 64 in direction 70.
[0059] As shown in FIG. 10b, once the distal end of graft 30 is
advanced through hole 64 in body organ tubing wall 66, sheath 68
can be drawn backward in direction 72. Drawing sheath 68 backward
releases wires 40, which assume their normal configuration by
radially expanding as shown by arrows 74.
[0060] As shown in FIG. 10c, sheath 68 is then drawn further
backward in direction 72, until wires 44 are released. Wires 44
then assume their normal configuration by radially expanding as
shown by arrows 76. Once wires 40 and 44 have assumed their
expanded configurations, graft 30 is held in place. Sheath 68 can
therefore be removed.
[0061] If the other end of graft 30 has connectors 34, the same
attachment process may be performed at that end of graft 30 by
inserting the preloaded sheath 68 through another hole in the body
organ tubing and removing sheath 68 through that hole (rather than
moving sheath 68 away from that hole as shown in FIGS.
[0062] Another aspect of the invention is shown in FIGS. 11 and 12.
As shown in FIG. 11, graft 30a may be provided with connectors 34a
having curved wires 40a and 44a. Wires 40a and 44a are curved to
varying degrees to match the curvatures encountered in making a
graft connection with a tubular portion of body organ tubing 32a.
The end view of FIG. 11 shows how wires 40a and 44a of the
connectors 34a that run along the curved portion of tubular body
organ tubing 32a are highly curved. The side view of FIG. 12 shows
how wires 40a and 44a of the connectors 34a that run along the
interior and exterior surfaces of tubular body organ tubing 32a
parallel to the longitudinal axis of tubular body organ tubing 32a
are not curved. Other connectors 34a that lie in planes not shown
in FIGS. 11 and 12 preferably have wires 40a and 44a that are less
curved than the wires 40a and 44a of FIG. 11 and that are more
curved than the wires 40a and 44a of FIG. 12. Body organ tubing 32a
is engaged in the gap 33a between wires 40a and 44a.
[0063] As shown in FIGS. 13 and 14, graft 30b may use connectors
34b with wires 40b that extend sufficiently into the interior of
tubular body organ tubing 32b that wires like wires 44a of FIG. 11
are not required on the exterior surface of body organ tubing 32b.
In particular, because wires 40b run down along the interior
surface of tubular body organ tubing 32 past bisecting plane 78, a
single set of wires 40b can hold graft 30b in place. The end view
of FIG. 13 shows how wires 40b that run along the curved portion of
tubular body organ tubing 32b are highly curved. The side view of
FIG. 14 shows how wires 40b of the connectors 34b that run along
the interior surface of tubular body organ tubing 32b in the axial
direction are not curved. Other connectors 34b that lie in planes
not shown in FIGS. 13 and 14 may have wires 40b that are less
curved than the wires 40b of FIG. 13 and that are more curved than
the wires 40b of FIG. 14 if desired.
[0064] Another connector arrangement is shown in FIGS. 15 and 16.
As shown in FIG. 15, graft 30c may use connectors 34c having some
wires 40c that extend completely around the interior of tubular
body organ tubing 32c, so that wires such as wires 44a of FIG. 11
are not required on the exterior surface of body organ tubing 32c.
In particular, wires 40c in the plane of the end view of FIG. 15
run completely around the interior surface of tubular body organ
tubing 32c, so that a single set of wires 40c holds graft 30c in
place. The side view of FIG. 16 shows how wires 40c of the
connectors 34c that run along the interior surface of tubular body
organ tubing 32c parallel to the longitudinal axis of tubular body
organ tubing 32c are not curved. Other connectors 34c that lie in
planes not shown in FIGS. 15 and 16 may be less curved than the
connectors 34c of FIG. 15 and more curved than the connectors 34c
of FIG. 16.
[0065] The connectors 34a, 34b, and 34c of FIGS. 1116 may be
installed using the installation procedure shown in FIGS. 10a, 10b,
and 10c.
[0066] Another type of wire connector structure that may be used is
shown in FIG. 17a. The wires 79 of wire connector 80 are preferably
integrally formed from a portion of frame 38 of graft 30. Wire
connector 80 has an upper annular portion 82 and a lower annular
portion 84. Portions 82 and 84 perform the connecting functions of
wires 40 and 44 of connectors such as connectors 34 of FIG. 2.
Graft 30 is connected to body organ tubing by engaging a portion of
body organ tubing in gap 33 between portions 82 and 84.
[0067] One suitable approach for fabricating connector structures
such as wire connector 80 is to form frame 38 over a mandrel and
then to heat treat frame 38 in a furnace. This technique causes
heat sensitive metals such as nitinol to retain the shape of the
mandrel after the heat treatment has been completed and the frame
38 has been removed from the mandrel. Similar deformation and heat
treatment steps can be used to form connectors 34 of FIGS.
1-16.
[0068] If desired, reinforcing wires 86 may be provided to line the
inner surface of connector structure 80 as shown in FIG. 17b.
Reinforcing wires 86 may be attached to frame 38 by any suitable
attachment technique, such as by welding or gluing.
[0069] One suitable technique for installing a graft 30 with a
connector 80 is shown in FIGS. 18a and 18b. As shown in FIG. 18a,
graft 30 is inserted into a hole 88 in body organ tubing wall 90
using sheath 92. Before insertion, graft 30 is preloaded into
sheath 92, thereby holding portions 82 and 84 of connector 80
radially inward and out of the way, so that graft 30 may be
inserted through hole 88. To insert graft 30 in hole 88 of body
organ tubing wall 90, sheath 92 and graft 30 are advanced in
direction 94.
[0070] As shown in FIG. 18b, once the distal end of graft 30 is
advanced through hole 88 in body organ tubing wall 90, sheath 92
can be drawn backward in direction 96. Drawing sheath 92 backward
releases portions 82 and 84 of wire connector 80, so that connector
80 assumes its normal radially-expanded configuration and holds
graft 30 in place. Sheath 92 can therefore be removed.
[0071] If the other end of graft 30 has a connector 80, the same
attachment process may be performed at that end of graft 30 by
inserting the preloaded sheath 92 through a hole in the body organ
tubing near that end and removing sheath 92 through that hole
(rather than moving sheath 92 away from the hole as shown in FIGS.
18a and 18b).
[0072] It is sometimes desirable to make connections between a
graft and a portion of body organ tubing at a non-right angle,
sometimes referred to herein as an oblique angle. The wire and
frame-based connectors of the present invention are suitable for
forming such connections.
[0073] A typical right-angle connection between a graft 30 and a
portion of body organ tubing 32 is shown in FIG. 19a. As shown in
FIG. 19b, such a right-angle connection creates a circular hole 98
in body organ tubing 32.
[0074] An oblique-angle connection between graft 30 and a portion
of body organ tubing 32 is shown in FIG. 20a. Making an
oblique-angle connection typically forms a hole 100 in body organ
tubing 32 that has a larger perimeter than the circular hole 98 of
FIG. 19b. The large perimeter of hole 100 provides a larger contact
area over which to form a firm connection between graft 30 and body
organ tubing 32. In addition, during some installation procedures
it may not be convenient or practical to use a right-angle
arrangement.
[0075] Any of connectors 32 or 80 may be used to form an
oblique-angle connection between a graft 30 and a portion of body
organ tubing 32. FIG. 21 shows how the obliquely-angled distal tip
102 of graft 30 may have connectors 34 formed from wires 40 and 44
around its periphery. When installed, wires 44 grip the outer
surface of body organ tubing 32, as shown in FIG. 22. Wires 40 (not
shown in FIG. 22) grip the corresponding inner surface of the body
organ tubing 32 of FIG. 22.
[0076] The oblique-angle connection between graft 30 and body organ
tubing 32 of FIG. 22 uses connectors 34 formed from wires 40 and
44. If desired, similar oblique-angle connections may be formed
using the webbed connector arrangement of FIG. 8, the looped
connector arrangement of FIG. 9, the curved connector wire
arrangements of FIGS. 11-16, or the integral frame connector
arrangement of FIGS. 17a and 17b. When used for oblique-angle graft
attachment procedures, sheaths such as sheath 68 of FIG. 10 and
sheath 92 of FIG. 18a preferably have obliquely-angled ends.
[0077] Wire connectors 32 and 80 may be provided as stand-alone
connectors if desired. For example, connectors such as connectors
34 of FIG. 2 may be attached to suitable ring structures 104, as
shown in FIG. 23. Ring structures 104, which are preferably formed
from a suitable elastomeric material, may be attached to a length
of natural graft 106 by sutures 108. The resulting natural graft
with artificial connectors may be used whenever a natural graft is
appropriate but the ease of installation provided by connectors 34
is desired. Similar ring-like standalone structures may be provided
using the webbed connector arrangement of FIG. 8, the looped
connector arrangement of FIG. 9, the curved connector wire
arrangements of FIGS. 11-16, or the integral frame connector
arrangement of FIGS. 17a and 17b.
[0078] It will be understood that the foregoing is only
illustrative of the principles of the invention, and that various
modifications can be made by those skilled in the art without
departing from the scope and spirit of the invention.
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