U.S. patent application number 10/411550 was filed with the patent office on 2003-10-16 for medical grafting methods & apparatus.
This patent application is currently assigned to St. Jude Medical ATG, Inc.. Invention is credited to Berg, Todd A., Boldenow, Gregory A., Bonilla, Luis, Cornelius, Rick, Galdonik, Jason A., Hindrichs, Paul J., Swanson, William J..
Application Number | 20030195535 10/411550 |
Document ID | / |
Family ID | 26863884 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030195535 |
Kind Code |
A1 |
Swanson, William J. ; et
al. |
October 16, 2003 |
Medical grafting methods & apparatus
Abstract
Methods and apparatus for making an anastomotic connection
between a first conduit and a second conduit. A connector structure
having a first end portion and a second end portion is positioned
about a balloon catheter, which when pressurized, expands to a
significant extent at the distal end thereof. The balloon enlarges
the connector structure when positioned at the distal end portion
of the balloon to create the anastomosis, and at the same time
reduces the axial length of the connector, thereby compressing the
first conduit to the second conduit, creating a hemodynamic seal
and a firm attachment of the two conduits. After enlargement, the
connector structure remains in place and adds structure to the
anastomosis. During introduction, the second end portion of the
connector is covered by a nosecone assembly to prevent trauma to
the second conduit while the apparatus is being introduced. The
nosecone assembly has a flexible structure which may change
configuration to expose the second set of members after insertion
into the second conduit and to allow removal of the nosecone after
deployment.
Inventors: |
Swanson, William J.; (St.
Paul, MN) ; Galdonik, Jason A.; (St. Louis Park,
MN) ; Hindrichs, Paul J.; (Plymouth, MN) ;
Boldenow, Gregory A.; (St. Michaels, MN) ; Berg, Todd
A.; (Stillwater, MN) ; Cornelius, Rick;
(Wayzata, MN) ; Bonilla, Luis; (Eden Prairie,
MN) |
Correspondence
Address: |
FISH & NEAVE
1251 AVENUE OF THE AMERICAS
50TH FLOOR
NEW YORK
NY
10020-1105
US
|
Assignee: |
St. Jude Medical ATG, Inc.
|
Family ID: |
26863884 |
Appl. No.: |
10/411550 |
Filed: |
April 9, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10411550 |
Apr 9, 2003 |
|
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|
09693578 |
Oct 20, 2000 |
|
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6602263 |
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60168200 |
Nov 30, 1999 |
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Current U.S.
Class: |
606/153 |
Current CPC
Class: |
A61B 17/11 20130101;
A61B 2017/0641 20130101; A61B 2017/00557 20130101; A61B 17/115
20130101; A61B 2090/0801 20160201; A61B 17/0644 20130101; A61B
46/17 20160201 |
Class at
Publication: |
606/153 |
International
Class: |
A61B 017/08 |
Claims
What is claimed is:
1. Introducing apparatus associated with a first vessel for
introduction of a portion of the first vessel into an opening of a
second vessel for making an anastomotic connection between the
first vessel and the second vessel with a connector structure,
comprising: a distal tapered portion; a intermediate portion
extending from the distal tapered portion and flexible between a
compacted configuration and an un-compacted configuration; and an
elongated tubular portion extending from the intermediate portion
and configured for positioning within an internal lumen of the
first vessel; wherein the moving the intermediate portion from the
compacted configuration to the uncompacted configuration advances
the distal tapered portion distally with respect to the elongated
tubular portion.
2. Introducing apparatus defined in claim 1, wherein the distal
tapered portion, the intermediate portion and the elongated tubular
portion define a common internal space in fluid communication.
3. Introducing apparatus defined in claim 1, wherein the
intermediate portion is configured to flexibly move between the
compacted configuration and the un-compacted configuration upon
introduction of fluid into the common internal space.
4. Introducing apparatus defined in claim 2, wherein the distal
tapered portion and the intermediate portion in the tapered
configuration define a substantially rigid structure in proportion
to the pressure of the expansion fluid in the common internal
space.
5. Introducing apparatus defined in claim 1, wherein the
intermediate portion, the distal tapered portion and the elongated
tubular portion are flexible between a substantially straight
configuration and a substantially curved configuration defining an
angle of between about 0 degrees and about 90 degrees.
6. Introducing assembly defined in claim 1, wherein the
intermediate portion in the compacted configuration defines an
annular recess for receiving a portion of the connector
structure.
7. Introducing apparatus associated with a first vessel for
introduction of a portion of the first vessel into an opening of a
second vessel for making an anastomotic connection between the
first vessel and the second vessel with a connector structure,
comprising: an elongated tubular portion configured for positioning
within an internal lumen of the first vessel and defining a distal
tip; and a plurality of tabs flexibly attached to the distal tip of
the elongated tubular portion, movable between a first
configuration extending proximally and radially outward from the
distal tip to define a substantially conical configuration and a
second configuration extending distally from the distal tip.
8. Introducing apparatus associated with a first vessel for
introduction of a portion of the first vessel into an opening of a
second vessel for making an anastomotic connection between the
first vessel and the second vessel with a connector structure,
comprising: an elongated tubular portion configured for positioning
within an internal lumen of the first vessel and defining a distal
tip; and an expandable balloon structure attached to the distal tip
of the elongated tubular portion, expandable between a first
unexpanded configuration and a second configuration defining a
substantially conical shape.
9. Introducing apparatus associated with a first vessel for
introduction of a portion of the first vessel into an opening of a
second vessel for making an anastomotic connection between the
first vessel and the second vessel with a connector structure,
comprising: an elongated tubular portion configured for positioning
within an internal lumen of the first vessel and defining an
internal lumen; and an expandable structure defining a first
collapsed configuration when positioned within the internal lumen
of the elongated tubular portion and a second configuration
expandable to conical configuration when released from the internal
lumen of the elongated tubular configuration.
10. Apparatus for use with a connector structure for making an
anastomotic connection between the first vessel and the second
vessel, the connector structure expandable between a first size and
a second size to attach the first vessel and the second vessel, the
apparatus comprising: a support structure; an expandable balloon
comprising a proximal portion attached to the support structure and
a distal portion attached to the support structure in an inverted
manner, such that the expandable balloon defines a maximum diameter
at a position substantially adjacent the distal end portion of the
expandable balloon.
11. Apparatus defined in claim 10, wherein the expandable balloon
defines the maximum diameter at a distance of about 2.5 mm from the
distal end portion of the expandable balloon.
12. Apparatus defined in claim 10, wherein the support structure
comprises an inner tubular shaft and an outer tubular shaft, and
wherein the proximal portion of the expandable balloon is attached
to the outer tubular shaft and the distal portion of the balloon is
attached to inner tubular shaft in the inverted manner.
13. Apparatus defined in claim 12, wherein the outer tubular shaft
and the inner tubular shaft are attached at a location adjacent to
the location of attachment of the proximal portion of the balloon
to the outer tubular shaft.
14. Apparatus defined in claim 10, wherein the expandable balloon
comprises a shoulder portion adjacent the distal end portion to
retain the connector structure in position about the expandable
balloon.
15. Apparatus defined in claim 10, wherein the support structure
and the expandable balloon are each provided with a junction to
allow the support structure and the expandable balloon to be
separated and reconnected.
16. Apparatus for inserting a distal portion of a hollow annular
anastomotic connector into an aperture in a side wall of a body
tissue conduit in a patient comprising: a structure comprising a
selectively inflatable and deflatable balloon, the structure having
an exterior surface that is reconfigurable, in use, from an early
configuration to a subsequent configuration, the early
configuration having annular periphery that gradually increases
from a first relatively small value at a distal end of the early
configuration to a second relatively large value at a more proximal
portion of the early configuration, and the subsequent
configuration having annular periphery that is substantially free
of abrupt increases in annular periphery in the distal direction,
the structure inside the more proximal portion of the early
configuration defining an annular hollow that is open in the
proximal direction for substantially concentrically receiving the
distal portion of the connector.
17. The apparatus defined in claim 16 wherein the structure is
further configured so that in the subsequent configuration the
distal portion of the connector is no longer disposed in an annular
hollow.
18. The apparatus defined in claim 16 wherein the structure is
further configured so that in the subsequent configuration the
structure can be withdrawn from the patient by pulling it
proximally through the connector.
19. The apparatus defined in claim 16 wherein the structure is
further configured to convert from the early configuration to the
subsequent configuration while inside the lumen of the body tissue
conduit and without injuriously deforming the body tissue
conduit.
20. The apparatus defined in claim 16 wherein the structure
comprises a member of flexible polymeric material.
21. The apparatus defined in claim 16 wherein the balloon has a
proximal annular portion that initially defines the annular hollow
when the balloon is not inflated.
22. The apparatus defined in claim 21 wherein the balloon is
configured so that inflation of the balloon substantially
eliminates the hollow and thereby exposes the distal portion of the
connector.
23. The apparatus defined in claim 16 wherein the balloon has a
proximal annular portion that initially defines the annular hollow
when the balloon is inflated.
24. The apparatus defined in claim 23 wherein the balloon is
configured so that deflation of the balloon substantially
eliminates the hollow and thereby exposes the distal portion of the
connector.
25. The apparatus defined in claim 16 wherein a proximal portion of
the balloon is initially folded in the proximal direction over the
distal portion of the connector.
26. The apparatus defined in claim 25 wherein the balloon is
configured to unfold when inflated and to thereby uncover the
distal portion of the connector.
27. The apparatus defined in claim 16 wherein a wire is attached to
the distal end of the structure such that the wire runs out of the
structure and connector in the proximal direction.
28. The apparatus defined in claim 27 wherein the wire is
substantially rigid and capable of altering the structure from the
early configuration to the subsequent configuration by advancing
the wire in the distal direction.
29. The apparatus defined in claim 27 wherein the wire is utilized
to indicate when the transformation from the early configuration to
the subsequent configuration is complete.
30. Apparatus for inserting a distal portion of a hollow annular
anastomotic connector into an aperture in a side wall of a body
tissue conduit in a patient comprising: a structure having an
exterior surface that is reconfigurable, in use, from an early
configuration to a subsequent configuration, the early
configuration having annular periphery that gradually increases
from a first relatively small value at a distal end of the early
configuration to a second relatively large value at a more proximal
portion of the early configuration, and the subsequent
configuration having annular periphery that is substantially free
of abrupt increases in annular periphery in the distal direction,
the structure inside the more proximal portion of the early
configuration defining an annular hollow that is open in the
proximal direction for substantially concentrically receiving the
distal portion of the connector; and annularly enlargeable
componentry disposed substantially concentrically inside the
connector and configured to selectively annularly enlarge the
connector.
31. The apparatus defined in claim 30 wherein the componentry is
additionally configured to selectively return to a less enlarged
state after annularly enlarging the connector.
32. The apparatus defined in claim 31 wherein the componentry is
configured, in its less enlarged state, for proximal removal from
the annularly enlarged connector.
33. The apparatus defined in claim 30 wherein the componentry
comprises: a selectively inflatable and deflatable balloon.
34. The apparatus defined in claim 30 wherein the structure and the
componentry are separately controllable for substantially
independent operation.
35. The apparatus defined in claim 30 wherein the componentry has a
hollow annular configuration disposed substantially concentrically
inside the connector, and wherein the structure is at least partly
supported relative to the componentry by support elements that pass
concentrically through the hollow annular configuration.
36. The apparatus defined in claim 30 wherein the componentry is
further configured to annularly enlarge the connector into
engagement with the side wall of the body tissue conduit.
Description
[0001] This application is a division of U.S. patent application
Ser. No. 09/693,578, filed Oct. 20, 2000, which is a nonprovisional
of U.S. provisional patent application No. 60/168,200, filed Nov.
30, 1999. All of these prior applications are hereby incorporated
by reference herein in their entireties.
BACKGROUND OF THE INVENTION
[0002] This invention relates to medical apparatus, and more
particularly to apparatus for use in making anastomotic connections
between tubular body fluid conduits in a patient.
[0003] There are many medical procedures in which it is necessary
to make an anastomotic connection between two tubular body fluid
conduits in a patient. An anastomotic connection (or anastomosis)
is a connection which allows body fluid flow between the lumen of
the two conduits that are connected, preferably without allowing
body fluid to leak out of the conduits at the location of the
connection. As just one example of a procedure in which an
anastomosis is needed, in order to bypass an obstruction in a
patient's coronary artery, a tubular graft supplied with aortic
blood may be connected via an anastomosis to the coronary artery
downstream from the obstruction. The anastomosis may be between the
end of the graft and an aperture in the side wall of the coronary
artery (a so-called end-to-side anastomosis), or the anastomosis
may be between an aperture in the side wall of the graft and an
aperture in the side wall of the coronary artery (a so-called
side-to-side anastomosis (e.g., as in published Patent Cooperation
Treaty ("PCT") patent application WO 98/16161, which is hereby
incorporated by reference herein in its entirety)). The graft may
be natural conduit, artificial conduit, or a combination of natural
and artificial conduits. If natural conduit is used, it may be
wholly or partly relocated from elsewhere in the patient (e.g.,
wholly relocated saphenous vein or partly relocated internal
mammary artery). Alternatively, no relocation of the graft may be
needed (e.g., as in above-mentioned application WO 98/16161 in
which a length of vein on the heart becomes a "graft" around an
obstruction in an immediately adjacent coronary artery). More than
one anastomosis may be needed. For example, a second anastomosis
may be needed between an upstream portion of the graft conduit and
the aorta or the coronary artery upstream from the obstruction in
that artery. Again, this second anastomosis may be either an
end-to-side anastomosis or (as shown, for example, in
above-mentioned application WO 98/16161) a side-to-side
anastomosis. Alternatively, no second, upstream anastomosis may be
required at all (e.g., if the graft is an only-partly-relocated
internal mammary artery).
[0004] The currently most common technique for making an
anastomosis is to manually suture the two tubular body fluid
conduits together around an opening between them. Manual suturing
is difficult and time-consuming, and the quality of the anastomosis
that results is highly dependent on the skill of the person doing
the suturing. In the case of coronary artery bypass procedures, one
source of difficulty for suturing of an anastomosis may be motion
of the heart. There is also increasing interest in procedures which
are less invasive or even minimally invasive. Such procedures have
potentially important advantages for patients, but they may
increase the difficulty of performing manual suturing of an
anastomosis by reducing or limiting access to the site within the
patient at which the anastomosis must be made. Various examples of
such less invasive or minimally invasive procedures are shown in
above-mentioned application WO 98/16161, Goldsteen et al. U.S. Pat.
No. 5,976,178, Sullivan et al. U.S. Pat. No. 6,120,432, Sullivan et
al. published PCT patent application WO 98/55027, and Berg et al.
U.S. Pat. No. 6,475,222, all of which are hereby incorporated by
reference herein in their entireties.
[0005] In the case of making a conventional end-to-side anastomosis
between a vein graft and the coronary artery, there are additional
difficulties which may arise. First, the relative sizes of the
coronary artery and the vein graft are different. For example, the
coronary artery may typically have an inner diameter of about 1.0
to 3.0 mm, whereas a vein graft, such as the saphenous vein, may
typically have an inner diameter of about 4 to 8 mm. This
discrepancy between vessel diameters, i.e., a "caliber mismatch,"
may present a challenge to the physician to match the end of the
relatively larger vein graft to an aperture in the side wall of the
relatively smaller coronary artery. The resulting quality and
amount of flow between the vein graft and the coronary artery,
along with the provision of an effective hemodynamic seal between
the two conduits, is often dependent upon the physician's skill in
making an effective junction between the two conduits.
[0006] Second, conventional end-to-side anastomosis typically joins
the graft conduit to the coronary artery at an angle with respect
to the lumen of the coronary artery, thus forming a junction at the
wall of the coronary artery. Further away from this junction, the
vein graft tends to lie against the heart structure, or
substantially parallel to the lumen of the coronary artery. The
transition of the vein graft from a substantially perpendicular
juncture to the coronary artery to a substantially parallel
position with respect to the coronary artery wall often occurs
abruptly, which may result in kinking of the vein graft, with
possibly reduced blood flow.
[0007] Third, joining vessels having relatively small diameters
(e.g., 1-4 mm) presents the additional consideration of keeping the
vessels open after the anastomosis has been made. It is therefore
helpful to provide the anastomosis with a diameter equal to or
larger than the diameter of the smaller vessel being joined. The
larger anastomosis is performed in order to minimize the risk of
closing off the flow due to the natural healing response. However,
it is a challenge to provide a delivery system which is compatible
with the dimensions of the anastomosis.
[0008] In view of the foregoing, it is an object of this invention
to provide apparatus that can be used to make anastomotic
connections in lieu of manual suturing.
[0009] It is another object of the invention to provide apparatus
that can be used to make anastomotic connections even though access
to the site of the anastomosis may be limited or even only indirect
or remote.
[0010] It is still another object of the invention to provide
apparatus that can be used to make anastomotic connections without
the need for a high degree of manual suturing skill.
[0011] It is yet another object of the invention to provide
apparatus for making anastomotic connections that is less adversely
affected than manual suturing by adjacent or nearby body motion
(e.g., motion of the patient's heart).
[0012] It is a further object of this invention to provide
apparatus for facilitating the making of higher quality anastomotic
connections more rapidly and with more consistent results than is
possible with prior art methods and apparatus such as manual
suturing.
[0013] It is another object of the invention to provide apparatus
for making a high quality anastomotic connection when joining two
conduits having different relative diameters.
[0014] It is another object of the invention to provide apparatus
for making a high quality anastomotic connection when joining two
conduits having relatively small diameters.
[0015] It is another object of the invention to provide apparatus
for making high quality anastomosis which allows the conduits to be
positioned in a substantially flat configuration with respect to
one another and which prevents kinking of the conduits.
SUMMARY OF THE INVENTION
[0016] An apparatus including a connector is provided to create an
anastomosis between two conduits. A particular application of this
invention is to join a saphenous vein graft (SVG) to a coronary
artery in a side-to-side anastomosis. The connector structure has a
first set of members that are used to secure the first conduit,
typically the SVG, and a second set of members that engage the
second conduit, typically the coronary artery.
[0017] The connector structure is mounted on a balloon catheter,
which when pressurized, expands to a significant extent at the
distal end thereof. The balloon enlarges the connector structure
when positioned at the distal end portion of the balloon to create
the anastomosis, and at the same time reduces the axial length of
the connector, thereby compressing the first conduit to the second
conduit, creating a hemodynamic seal and a firm attachment of the
two conduits. After enlargement, the connector structure remains in
place and adds structure to the anastomosis.
[0018] The second set of members is covered by a nosecone assembly
to prevent trauma to the second conduit while the apparatus is
being introduced. The nosecone assembly has a flexible structure
which may change configuration to expose the second set of members
after insertion into the second conduit and to allow removal of the
nosecone after deployment.
[0019] The method for creating the anastomosis may comprise
providing a connector and a delivery apparatus including an
expansion balloon and a nosecone assembly. A next step may include
making an aperture in the wall of the first conduit proximal to the
distal end of the first conduit. The first conduit is then attached
to the connector structure. More particularly, the first set of
members of the connector structure may then pierce the wall of the
first conduit. A locating ring, which may be colored with titanium
dioxide, is placed about the first conduit adjacent the first set
of members to provide an indication to the physician during
delivery.
[0020] At the operative site, a second aperture is made in the
second conduit wall. According to one embodiment, the second
conduit may be cut and then dilated. The delivery system and the
connector is introduced into the aperture in the second conduit.
More particularly, the nosecone, in an introduction configuration,
is inserted into the second conduit substantially axially to the
lumen of the second conduit. The locating ring provides an
indication that the first aperture in the first conduit is
positioned adjacent the second aperture in the second conduit. The
locating ring may provide a visual indication or a tactile
indication when the locating ring is in contact with the wall of
the second conduit.
[0021] The nosecone may then be changed to the removal
configuration to uncover the second set of members. In an
embodiment, the nosecone is a balloon structure which is inflated
to uncover the second set of members. The nosecone assembly may be
flexible, such that further advancement of the nosecone allows the
nosecone to be positioned substantially parallel to the lumen of
the second conduit. The delivery system may then be turned from a
substantially axial position to a position at 90 degrees with
respect to the lumen and the wall of the second conduit.
[0022] The balloon catheter is designed to allow significant
expansion at its distal end portion. The connector, which has been
positioned adjacent this distal end portion, may then be enlarged
by expanding the balloon to make the anastomosis between the first
and second conduits. More particularly, the connector structure
enlarges radially and may shorten axially to approximate the first
and second set of members of the connector, and thereby approximate
the tissue of the first and second conduits to provide a seal,
which is hemodynamic and has sufficient mechanical integrity and
strength to provide durability. Once the connector structure is
enlarged, the balloon and/or nosecone is deflated, and the delivery
system may be removed and the first conduit may be ligated distal
to the anastomosis without compromising the first conduit
lumen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a simplified sectional view of the apparatus and a
first conduit in accordance with the invention.
[0024] FIG. 2 is a planarized projection of a component apparatus
of FIG. 1 in accordance with the invention.
[0025] FIG. 3 is a perspective view of the component apparatus of
FIG. 2 in accordance with the invention.
[0026] FIG. 4 is a planarized projection of the component apparatus
of FIG. 2 in another configuration in accordance with the
invention.
[0027] FIG. 5 is a perspective view similar to FIG. 3 of the
component apparatus of FIG. 2 in another configuration in
accordance with the invention.
[0028] FIG. 6 is a planarized projection of another embodiment of
the component of FIG. 2 in accordance with the invention.
[0029] FIG. 7 is a sectional view of the component of FIG. 6 in
another configuration in accordance with the invention.
[0030] FIG. 8 is a sectional view of another component apparatus of
FIG. 1 in accordance with the invention.
[0031] FIG. 9 is a sectional view of a prior art apparatus.
[0032] FIG. 10 is a simplified view of the component apparatus of
FIGS. 2-5 and the component apparatus of FIG. 8 in accordance with
the invention.
[0033] FIG. 11 is a sectional view taken along line 11-11 of FIG.
10 in accordance with the invention.
[0034] FIG. 12 is a sectional view of the component apparatus shown
in FIG. 8 and the component apparatus of FIGS. 2-5 in another
configuration in accordance with the invention.
[0035] FIG. 13 is a sectional view of a component apparatus of FIG.
1 in a first condition in accordance with the invention.
[0036] FIG. 14 is a sectional view of the component apparatus of
FIG. 13 in a second condition in accordance with the invention.
[0037] FIG. 15 is perspective view of additional apparatus in
accordance with the invention.
[0038] FIG. 16 is a sectional view of the apparatus of FIG. 15,
illustrated with the first conduit, in accordance with the
invention.
[0039] FIG. 17 is a sectional view similar to FIG. 16, illustrating
the apparatus of FIG. 1 in an earlier stage of the procedure in
accordance with the invention.
[0040] FIG. 18 is a sectional view similar to FIG. 17, illustrating
additional apparatus in accordance with the invention.
[0041] FIG. 19 is an elevation view of a component apparatus of
FIG. 1 in accordance with the invention.
[0042] FIG. 20 is a side view of the component apparatus of FIG.
19, taken from direction 20 of FIG. 19 in accordance with the
invention.
[0043] FIG. 21 is a view in partial section of the apparatus of
FIG. 1 in an early stage of a procedure in accordance with the
invention.
[0044] FIG. 22 is a view similar to FIG. 21 illustrating a further
stage of a procedure in accordance with the invention.
[0045] FIG. 23 is a view similar to FIG. 22 illustrating a later
stage of a procedure in accordance with the invention.
[0046] FIG. 24 is a view similar to FIG. 23 illustrating a still
later stage of a procedure in accordance with the invention.
[0047] FIG. 25 is a view similar to FIG. 24 illustrating yet
another stage of a procedure in accordance with the invention.
[0048] FIG. 26 is a sectional view taken along lines 26-26 of FIG.
25 in accordance with the invention.
[0049] FIG. 27 is an elevational view in accordance with the
invention.
[0050] FIG. 28 is a sectional view similar to FIG. 21, illustrating
another procedure in accordance with the invention.
[0051] FIG. 29 is a sectional view similar to FIG. 21, illustrating
yet another procedure in accordance with the invention.
[0052] FIG. 30 is a sectional view similar to FIG. 1, illustrating
another procedure in accordance with the invention.
[0053] FIG. 31 is a perspective view of component apparatus similar
to that illustrated in FIG. 18, according to another embodiment, in
accordance with the invention.
[0054] FIG. 32 is a perspective view of the component apparatus of
FIG. 31 in another configuration, in accordance with the
invention.
[0055] FIG. 33 is a sectional view similar to FIG. 22, illustrating
the component apparatus of FIGS. 31-32 in an early stage of the
procedure in accordance with the invention.
[0056] FIG. 34 is a sectional view similar to FIG. 33, illustrating
a later stage of the procedure in accordance with the
invention.
[0057] FIG. 35 is a sectional view similar to FIG. 34, illustrating
a still later stage of the procedure in accordance with the
invention.
[0058] FIG. 36 is a sectional view of component apparatus similar
to that illustrated in FIG. 18, according to another embodiment, in
accordance with the invention.
[0059] FIG. 37 is a perspective view of the component apparatus of
FIG. 36 in another configuration, in accordance with the
invention.
[0060] FIG. 38 is a sectional view similar to FIG. 22, illustrating
the component apparatus of FIGS. 36-37 in an early stage of the
procedure in accordance with the invention.
[0061] FIG. 39 is a sectional view similar to FIG. 38, illustrating
a later stage of the procedure in accordance with the
invention.
[0062] FIG. 40 is a sectional view of component apparatus similar
to that illustrated in FIG. 18, according to still another
embodiment, in accordance with the invention.
[0063] FIG. 41 is a perspective view of the component apparatus of
FIG. 40 in another configuration, in accordance with the
invention.
[0064] FIG. 42 is a sectional view similar to FIG. 22, illustrating
the component apparatus of FIGS. 40-41 in an early stage of the
procedure in accordance with the invention.
[0065] FIG. 43 is a sectional view similar to FIG. 42, illustrating
a later stage of the procedure in accordance with the
invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0066] Although the invention has other possible uses, the
invention will be fully understood from the following explanation
of its use in providing a bypass around an obstruction in a
patient's vascular system.
[0067] FIG. 1 illustrates the apparatus 100 in accordance with the
invention, which is illustrated along with a connector structure
200, and a first conduit 10, which is typically a graft conduit and
may be a natural conduit, such as a saphenous vein graft (SVG) or
similar, or an artificial conduit. Apparatus l00 comprises a number
of component elements for delivery and deploying the connector
apparatus 200 and the first conduit 10 to the operative site to
make an anastomotic connection between first conduit 10 and a
second conduit, which is typically a patient's natural body conduit
(see, e.g., FIG. 21). An apparatus for deploying the connector
structure 200, such as balloon catheter 300, is useful for
enlarging the connector structure 200 to join the two conduits. A
nosecone apparatus 400 is useful to assist insertion of apparatus
100 into an aperture in the second conduit and to shield the
connector structure 200 from damaging the second conduit during
such insertion into the second conduit. A location ring 500 is
positioned about an aperture 12 in the first conduit 10 and about
the connector structure 200. The location ring 500 may be helpful
to indicate the position of the first conduit 10 and the connector
structure 200 during the anastomosis procedure.
[0068] Apparatus 100 and connector structure 200 are particularly
useful in making a side-to-side anastomosis between the first and
second conduits. This procedure accommodates the connector
structure 200 to different sizes of conduits, provides an
anastomosis size approximately equivalent to the second conduit
diameter, and provides an optimal takeoff angle for the first
conduit to prevent kinking. Apparatus 100 and connector structure
200 are also useful in making an end-to-side anastomosis.
[0069] FIG. 1 illustrates that the aperture 12 has been made in the
first conduit 10 adjacent to the distal end portion 14 of the first
conduit 10. This configuration, as will be described in greater
detail below, permits a side-to-side anastomotic connection to be
made with the second conduit. More particularly, a fluid tight
connection is made through the side wall of first conduit 10 and
through the side wall of the second conduit. Moreover, the
apparatus 100 may be inserted through the end portion 14, such that
the opposite end portion of first conduit 10 (not shown) is free.
This configuration allows the side-to-side anastomosis to be made
after a first anastomosis, e.g., at the aorta of the patient.
Alternatively, the apparatus 10 may be used to make an end-to-side
anastomosis, when the end portion 14 of the first conduit 10 is
attached to the connector structure 200, and which is described in
greater detail herein with respect to FIG. 30.
Connector Structure
[0070] FIGS. 2 and 3 illustrate an embodiment of the connector
structure 200. FIG. 2 shows a planar development of what is
actually an integral, one-piece (unitary), annular structure.
(Additional features of the connector structure and apparatus for
applying the connectors are disclosed in Berg et al. published PCT
patent application WO 99/38454; Swanson et al. U.S. Pat. No.
6,113,612; and Grudem et al. published PCT patent application WO
00/53104, each of which is incorporated by reference in their
entirety herein.) In particular, the left and right edges of the
structure shown in FIG. 2 are actually joined to and integral with
one another. Thus, the actual structure is as shown in FIG. 3,
although FIG. 2 is useful to more clearly reveal the details of
various features of the structure.
[0071] An illustrative material for connector structure 200 is 316
stainless steel. Other examples of suitable materials include
tantalum, tungsten, platinum, other steels, and nitinol. Connector
structure 200 may be advantageously produced by starting with a
single, unitary metal tube, such as a hypotube, and removing
selected material until only the structure shown in FIG. 3 remains.
For example, laser cutting may be used to remove material from the
starting tube in order to produce connector structure 200. Although
connector structures 200 can be made in various sizes for various
uses, a typical connector structure has an inner diameter in the
range from about 0.025 to about 0.100 inches. For example, an
embodiment may have an initial inside diameter of about 0.042
inches, an outside diameter of about 0.05 inches, a material
thickness of about 0.004 inches, and an initial length of about
0.075 to about 0.085 inches.
[0072] Connector structure 200 may be described as including
axially spaced first and second cell portions 202 and 204,
respectively. According to one embodiment, the connector structure
200 comprises six repeating first cell portions 202 and six
repeating second cell portions 204. The connector structure 200 may
have fewer or more than six each of first cell portions 202 and
second cell portions 204, depending on the diameter of the tube
used to manufacture the connector structure 200 and the resulting
enlarged diameter desired. Alternatively, the connector structure
200 may have different configurations of cells and geometries.
[0073] The width 210 of the members which make up the first and
second cell portions 202 and 204 is typically in the range of about
0.003 to about 0.0035 inches. The dimensions 212, 214, and 216 are
each about 0.021 inches in the preferred embodiment. The segment of
the connector structure associated with dimension 212 defines a
distal portion 206 of the connector structure 200. The segment
associated with dimension 214 defines a medial portion 207, and the
segment associated with dimension 216 defines a proximal portion
208. These dimensions 212/214/216 may be varied from these examples
to suit the dimensions of the conduit and the aperture of the
proposed anastomosis.
[0074] First cell portion 202 includes annularly spaced, but
adjacent, longitudinal members 230a and 230b. The ends of these
members are connected to one another at 232a, 234b, and 236b.
Annularly adjacent ones of these cells are connected to one another
at 234b. As will be described below, annular expansion of cells 202
permits annular enlargement of connector structure 200. A pair of
members 230a, along with the portion 232a joining adjacent members
230a together, may comprise one of a second plurality of fingers
233 for engaging the second conduit 20, as will be described
herein. The embodiment shown in FIGS. 2-5 are illustrated with six
of the second plurality of fingers 233, for example.
[0075] Some of the first cell portions 202 may include an annularly
spaced distal member 218 that in this case has a free end portion
220, that is sharply pointed and that points toward proximal
portion 208. Member 218 may be about 0.004 to about 0.020 inches in
length for thin-walled conduits. The dimensions may be altered
according to the thickness of the conduits to be joined. Each of
members 218 is deflectable radially outwardly from the remainder of
connector structure 200 as shown, for example, in FIG. 3. Distal
members 218 may be deflected radially outward or angled backward
towards the proximal end portion 208 of the connector structure
200. This outward deflection is preferably at least partly
plastic.
[0076] First cell portion 202 may also include an annularly spaced
proximal member 222 that in this case has a free end portion 224
that is sharply pointed and that points toward distal portion 206.
Proximal members 222 are about 0.008 to about 0.120 inches in
length, wherein a length of about 0.030 inches is preferable for
the aorta. Each of proximal members 222 is deflectable radially out
from the remainder of connector structure 200 as shown, for
example, in FIG. 3. Again, this outward deflection is preferably at
least partly plastic.
[0077] The above-mentioned outward deflection of distal members 218
and proximal members 222 may be produced by putting the connector
structure on a mandrel and prying members 218 and 222 radially
outward. Following deflection of members 218 and 222, an initial
axial spacing 250 of about 0.050 inches is defined therebetween.
This dimension is appropriate for thin-walled vessels. The
dimension may be changed depending on the thickness of the first
and second conduits to be joined.
[0078] Second cell portions 204 may include annularly adjacent
longitudinal members 230b, and 230c, the axially spaced ends of
which are connected at 234b, 236b, and 238c. (It should be noted
that members 230b are in common with cells 202 and 204.) Annularly
adjacent cells of this kind are connected to one another at
locations like 236b. As will be described below, annular expansion
of second cell portions 204 permits annular enlargement of
connector structure 200. A pair of members 230c, along with the
portion 238c joining adjacent members 230c together, may comprise
one of a first plurality of fingers 235 for engaging the first
conduit 10. The embodiment shown in FIGS. 2-5 are illustrated with
six of the first plurality of fingers 235, for example.
[0079] The connector structure 200 is preferably annealed. The
connector structure 200 may also be used in the full hard or
partially hard state. The connector structure 200 will also
typically require other processing appropriate for an implantable
device such as, for example, polishing, passivation, and
cleaning.
[0080] FIGS. 4 and 5 illustrate the enlarged condition of connector
structure 200. A design consideration for connector structure 200
is that its enlarged diameter should be similar to the inner
diameter of the smaller of the two conduits being joined. Connector
structure 200 is formed in such a way that it is annularly
enlargeable (e.g., by inflation of a balloon that is temporarily
disposed inside the connector structure, such as balloon catheter
300, as will be described in greater detail herein). An embodiment
of the connector structure 200, enlarged with a balloon of 3.5 mm
in diameter, will typically enlarge to an internal diameter of
about 0.115 inches if unconstrained and to about 0.09 to about 0.11
inches when connecting two conduits, such as an SVG and a coronary
artery. (Such difference is due to the constricting effect of the
conduits, as will be described in greater detail herein.)
[0081] A planar development of the annularly enlarged condition of
connector structure 200 is shown in FIG. 4. The annular
enlargeability of connector structure 200 is provided by annularly
expanding cell portions, such as first and second cell portions,
described above. In this way connector structure 200 is annularly
enlargeable by annularly enlarging each of the above-mentioned
first cell portions 202. In addition to the cells that are
described above, connector structure 200 includes other, similarly
annularly expandable cell portions 204 that are axially and
annularly offset from the first-described cell portions 202. Thus
again the connector structure 200 is annularly enlargeable by
annularly enlarging these cell portions 204.
[0082] It will be appreciated that as connector structure 200
annularly enlarges, it generally axially shortens. In other words,
as cell portions 202 and 204 widen in the annular direction, they
shorten in the axial direction. As the connector structure 200 is
enlarged in position to join the two conduits together, it is
desirable for the distal portions 206 and the proximal portions 208
to deflect radially outward to greater diameter (distal diameter
240 and proximal diameter 242, respectively) than the medial
diameter 244 associated with the medial portion 207. (See, e.g.,
FIGS. 5 and 12.) The overall annular enlargement of connector
structure 200 along with the relatively greater enlargement of
distal portion 206 and proximal portion 208 together decrease the
axial spacing between cell portions 202 and 204, and more
particularly decrease the axial spacing between distal members 218,
and proximal members 224 to a reduced axial spacing 250 (FIG. 5).
The approximation of members 218 and 222 also helps to draw the
edges of the two conduits together to create a good seal
therebetween (See, FIGS. 24-25).
[0083] Another embodiment of the connector structure is connector
structure 270, which is illustrated in FIGS. 6-7. Connector
structure 270 is substantially identical to connector 200, with the
differences noted herein. As shown in FIG. 6, a plurality of spacer
members 272 are added between pairs of members 230a and pairs of
members 230b. Each spacer member 272 is an integral portion of
connector structure 270, and it may have a length of about 0.010
inches. The spacer members 272 extend the dimension 214' associated
with the medial portion 207' of the connector structure 270.
[0084] The spacer members 272 extend the overall length of the
connector structure 270, without substantially changing the
diameters of the enlarged connector structure. This is helpful
where the thickness of the vessel walls increases, but the
anastomosis diameter remains constant. More particularly, when the
connector 270 is enlarged, the end portions 206 and 208 are
deflected to diameters 240 and 242, respectively, which is
substantially the same extent as for a connector 200 not having a
spacer member. In addition, the diameter 244 associated with the
medial portion 207' remains substantially constant as well.
However, the axial distance 250 between members 218 and 222 is
increased, preferably to accommodate an increased thickness of the
conduit walls.
[0085] Another embodiment of connector structure is contemplated
which is substantially identical to connector structure 200
described above, with the following distinctions. This connector
structure also has a third set of members located between members
218 and 222 described above. The third set of members are located
on the connector structure distal to the point of the connector
structure's minimum enlarged diameter, as described above. The
third set of members are used such that the perimeter of the hole
made in the first conduit is pressed down against them. This
configuration assists in drawing the perimeter of the hole in the
first conduit through and into the hole in the second conduit
before the connector structure is enlarged. The embodiment of the
connector structure with three sets of prongs is useful for either
a side-to-side anastomosis or an end-to-side anastomosis.
[0086] A typical use of connector structure 200 is in a coronary
artery bypass procedure, to provide an anastomosis between an
aperture in a first conduit, such as a tubular graft conduit, and
an aperture in a side wall of a second conduit, such as a coronary
artery.
Balloon Catheter
[0087] A balloon catheter 300 in accordance with the invention is
illustrated in FIG. 8. The balloon catheter 300 may be comprised of
the balloon 302, an outer tubular shaft 304, an inner tubular shaft
306, and a hub 308. The hub 308 has a port 310 which allows access
to the lumen 312 of the inner tubular shaft 306, and another port
314 which allows access to the lumen 316 defined between the inner
tubular shaft 306 and the outer tubular shaft 304. The lumen 316 is
in communication with the interior of the balloon 302 and
introduces fluid to inflate the balloon 302. The balloon 302 may
comprise a substantially constant diameter barrel portion 318, a
tapered distal portion 320, and a tapered proximal portion 322.
[0088] A balloon catheter 30 known in the art is shown in FIG. 9,
and may include a balloon 32 and a tubular structure 34. A port 36
is typically defined in the tubular structure 34 to supply the
fluid to the balloon 32. The balloon 32 may include a constant
diameter barrel portion 38, a distal tapered portion 40, and a
proximal tapered portion 42. The tapered portions 40 and 42 are
attached to the tubular structure 34 in an "un-inverted manner."
The term "un-inverted," as used herein, shall refer to the
condition of an end portion of the balloon which gradually tapers
from one axial end to another. For example, the tapered portions 40
and 42 of balloon 32 are mounted to the tubular shaft 34 in an
un-inverted manner, i.e., the tapered portions 40 and 42 gradually
are reduced in size from the barrel portion 38 to the end portions
attached to the tubular shaft. Similarly, the proximal end portion
322 of balloon 302 (as shown in FIG. 8) is un-inverted. A
characteristic of the un-inverted configuration is that the portion
of the balloon having the largest diameter is typically a
proportionally long distance from the attachment point of the
balloon.
[0089] Conversely, the term "inverted" shall refer to the condition
of the balloon wherein an inflated portion of the balloon extends
beyond the distal bond 352. Thus, the tapered portion of the
balloon does not taper gradually, but may "double-back" on itself.
With continued reference to FIG. 8, the distal portion 320 of the
balloon 302 may be attached to the inner tubular shaft 306 in an
inverted manner. An advantage of an inverted configuration is that
the distalmost portion of the balloon 302 may achieve a relatively
large diameter at a shorter distance from the distal end portion of
the balloon. As will be described in greater detail herein, the
inverted attachment configuration of distal tapered portion 320
permits the connector structure 200 to be positioned close to the
distal end portion of the balloon 302, and still be sufficiently
enlarged by the balloon 302 when the balloon 302 is expanded to
install the connector structure 200.
[0090] The connector structure 200 may be placed annularly about
the balloon 302 of balloon catheter 300, as illustrated in FIGS. 10
and 11. The connector structure 200 is typically installed when
balloon 302 is disposed in its unexpanded configuration. As
illustrated in FIG. 11, the unexpanded configuration of balloon 302
may define a plurality of folded portions 330 that are expanded
upon introduction of fluid into the balloon 302.
[0091] With continued reference to FIG. 10, the connector structure
200 is oriented such that distal members 218 are positioned
adjacent to the distal end portion of the balloon 302. As will be
described in greater detail herein, the design of balloon 302
allows the connector structure 200 to be positioned as close as
possible to the distal end portion of the balloon 302. Certain
features may be useful to hold the connector structure 200 in place
on the balloon 302. Particularly when the connector is mounted
adjacent the distal end of the balloon 302 as described above, it
is important to prevent the connector from slipping forward, where
it may not be enlarged as fully as desired because it is positioned
over a smaller diameter region of the balloon 302. In one
embodiment, the connector structure 200 is mounted over the balloon
302, which is "pre-inflated," or inflated to a low pressure to hold
the balloon 302 in place without enlarging the connector structure
200. According to another embodiment, a larger diameter may be heat
set in the balloon 302 just distal of the distal portion of the
connector structure 200 to prevent the connector from sliding
forward. According to yet another embodiment, the balloon 302 may
be covered with a material having a high coefficient of friction to
create higher frictional forces between the balloon and the
connector. A material such as, for example, urethane in the 30D-60D
durometer range may be useful for this purpose. This material may
be provided with a separate sleeve or with a co-extrusion of the
softer material and the base balloon material at the time of
extruding the balloon blank. According to yet another embodiment,
nosecone 400 (described in greater detail herein) may be positioned
distal to the connector structure 200 to hold the connector
structure 200 in position on the balloon 302 at least until the
nosecone 400 is deployed to permit connector enlargement.
[0092] As illustrated in FIG. 12, there are several design
considerations with regard to the construction of the balloon
302.
[0093] First, the configuration of the balloon 302 should allow the
distal end of the connector structure 200 (approximately adjacent
the free end portion 220 of member 218) to be positioned at a
reduced distance 340 from the distal end of the balloon 302.
Distance 340 is advantageously as small as possible because the
anastomosis is made by inserting the distal end of the balloon 302
and the connector structure 200 into an aperture in the second
conduit to be joined. More particularly, this distance 340 should
fit within the conduit to be joined when the delivery apparatus 100
is at 90 degrees with respect to the conduit prior to deploying the
connector structure 200 (see, FIG. 23). Therefore, the balloon 302
should be designed to avoid contacting the opposite inner wall of
the second conduit, or dilating the inner lumen of the second
conduit.
[0094] Second, the balloon 302 should expand sufficiently at
distance 340 in order to adequately enlarge the connector structure
200. Consequently, the balloon 302 must achieve a minimum required
dimension 342 (radius of the balloon 302 is shown in FIG. 12) which
is sufficient to enlarge the connector structure 200 to the
required dimension. Moreover, since the end portions 206 and 208 of
the connector are designed to expand to a greater extent than the
medial portion 207, balloon 302 should be designed to expand to a
dimension larger than the enlarged dimension of the connector
structure.
[0095] Third, the balloon 302 should be configured to expand to a
dimension at least as large as the diameter of the lumen of the
second connector to be joined.
[0096] To meet these design objectives, the balloon 302 is
configured to expand to a minimum required dimension 342 as close
to the distal end of the balloon 302 as possible. In other words,
balloon 302 is designed to achieve a substantially large diameter
adjacent the distal end portion. This configuration may be achieved
by maintaining the inverted configuration of balloon 302 and by
minimizing the average radius of curvature 344 of the distal end
portion of the balloon. As the radius of curvature 344 decreases,
the distance 346 from the distal end of the balloon 302 to minimum
required dimension 342 also decreases.
[0097] With reference to FIGS. 8 and 12, several features of the
balloon catheter 300 are helpful to maintain the inverted
configuration and to minimize the radius of curvature 344. First,
the balloon catheter 300 may be designed to prevent relative
movement between tubular shafts 304 and 306. This feature may help
to prevent the distal end portion 320 of the balloon 302 from
un-inverting when the balloon 302 is pressurized. If the distal end
320 of the balloon 302 is permitted to become partially
un-inverted, the distance 346 from the end of the balloon 302 to
the minimum required dimension 342 may increase. For example, the
proximal balloon bond 350 may also provide an attachment of the
inner tubular shaft 306 to the outer tubular shaft 304. This bond
may be an adhesive bond, a thermal weld, or by using a single
extrusion having several lumens instead of the inner tubular shaft
304 and outer tubular shaft 306. (It is understood that the
connection of inner tubular shaft 306 to outer tubular shaft 304
permits fluid flow into balloon 302 and does not completely block
lumen 316.)
[0098] Another feature which may maintain the inverted
configuration and reduce the radius of curvature 344 of the balloon
302 is the strength of the inner tubular shaft 306 which resists
elongation when under tension generated by the inflation of the
balloon 302. Elongation of the inner tubular shaft 306 may also
allow the distal portion 320 of the balloon 302 to partially
un-invert. Therefore, the portion of the inner tubular shaft 306
between the location 350 where the inner tubular shaft 306 and the
outer tubular shaft 304 are bonded together and the distal balloon
bond 352 should have relatively high tensile strength. According to
a preferred embodiment, this may be accomplished by using a polymer
encased stainless steel braid tubing for the inner tubular member
306. This tubing may have a PTFE inner layer for lubricity for
introducing additional apparatus, such as nosecone 400, as will be
described in greater detail herein; a stainless steel middle layer;
and a nylon outer layer which is bonded to the balloon 302 and the
outer tubular shaft 304. Alternative configurations for achieving
adequate tensile strength and stiffness for this segment of the
inner tubular shaft 306 may include reinforcing the tubing with
straight wires, sheathing this region with a stiffer tubing
material, or by using thicker wall dimensions or stiffer
materials.
[0099] A further feature which may maintain the inverted
configuration and reduce the radius of curvature 344 of the balloon
302 concerns which portions of the balloon 302 are inverted. The
balloon configuration may include inversion of the distal tapered
portion 320 of the balloon 302 as well as inversion of a portion of
the constant diameter barrel 318. Typically, inverting only the
distal tapered portion 320 of the balloon 302 may result in a
larger radius of curvature 344 than inverting the distal tapered
portion 320 along with a portion of the constant diameter barrel
318.
[0100] Yet another feature that maintains the inverted
configuration and a reduced radius of curvature 344 of the balloon
302 is providing resistance to bending of the balloon 302. If the
balloon 302 is permitted to bend, this may increase the radius of
curvature 344 of the balloon 302 as well. Resistance to bending may
be promoted by providing uniform wall thickness of the balloon 302
and by providing resistance against balloon elongation. Providing
uniform wall thickness is largely a function of providing uniform
wall thickness in the extruded balloon blanks. Other procedures
known in the art promote uniform wall thickness. For example,
balloon elongation may be minimized by reducing the overall length
of the balloon and by forming the balloon from relatively
inelastic, highly oriented materials. In a preferred embodiment,
the balloon 302 may have a length of about 0.5 to about 1 cm. The
balloon 302 may be manufactured from a material, such as for
example, a polyamide, such as Nylon 12. Other preferred materials
may include PET, polyamide copolymers, polyimide, or other
materials known in the art.
[0101] In use, the balloon may be subject to stresses, such as
longitudinal forces during insertion into the opening in the second
conduit. As a result of these stresses, the balloon 302 may "roll,"
or shift proximally with respect to tubular shafts 304 and 306.
This proximal rolling may cause the distal end portion of the
balloon 302 to become partially un-inverted. Another feature may be
provided to inhibit the expanded balloon 302 from rolling. As
illustrated in FIG. 8, an outer sleeve 376 may be positioned about
the periphery of the proximal end portion 322 of the balloon 302,
and spaced apart from the proximal bond 350. The outer sleeve 376
provides additional stability to the balloon against rolling, by
contacting the proximal portion 322 and maintaining the inverted
configuration illustrated in FIG. 8.
[0102] The combination of any or all of these design features are
useful in providing a balloon structure having a preferred distance
340 of 2.0 mm or less (FIG. 12). This reduced distance 340 is very
valuable when the balloon 302 is to be used to enlarge a connector
structure 200 in conduits smaller than 4 mm. For distances 340
greater than about 2 mm, then the connector structure 200 may be
mounted on a portion of the balloon that is tapered distally (i.e.,
it is in a portion that has yet reached the minimum required
dimension 342) or the connector structure 200 may not be seated
properly with respect to the conduit, if the tip of the balloon 302
is in contact with the back wall of the second conduit when the
system is rotated to its perpendicular configuration.
[0103] In addition to minimizing the elongation of the balloon,
there are yet other design factors which are important in selecting
the balloon material. One factor is the pressure requirements of
the balloon. To properly enlarge the connector, the balloon should
be able to withstand a balloon inflation pressure of about 18
atmospheres for a 3.5 mm diameter balloon. Another factor is the
ability to produce a predictable diameter when inflated to high
pressures. The same materials described above which have low
elongation as balloons are useful to meet the high pressure
requirements and also have a predictable diameter at high
pressure.
[0104] In order to create the greater deflection of the ends of the
connector structure 200 as described above with respect to FIG. 12,
a balloon 302 having a diameter larger than the connector structure
200 may be used to enlarge the connector structure. The size of the
balloon 302 in its expanded state and the required pressure of the
balloon to enlarge the connector structure along with the conduit
are related. For example, a connector structure being enlarged by a
balloon 302 which is 0.5 mm larger than the connector structure's
enlarged diameter may require 18 atm of pressure to reach full
enlargement, while a balloon having a diameter 1 mm larger than the
connector's enlarged diameter may require 14 atm of pressure to
reach full enlargement. The design of the connector, when
positioned around the balloon, may affect the expansion
characteristics of the balloon.
[0105] As described above, several design considerations with
respect to the balloon and connector sizing are (1) the
configuration of the balloon should allow the connector to be
placed close to the distal end of the balloon so that the balloon
does not dilate the inner lumen of the second conduit; (2) the
diameter of the expanded balloon should be larger than the enlarged
diameter of the connector to allow the end portions to enlarge to a
greater degree than the medial portion; and (3) the diameter of the
enlarged connector should be similar to the diameter of the smaller
of the two conduits. An additional design consideration is that the
diameter of the expanded balloon should be smaller than the inner
diameter of the first conduit to avoid dilating the first conduit.
Taking these design considerations into account, it is desirable to
use a balloon with an expanded diameter that is about 0.5 mm to
about 1.25 mm larger than the enlarged diameter of the connector.
If the connector is mounted adjacent the distal end portion of the
balloons constant diameter barrel portion 318, and the expanded
diameter of the balloon 302 is 0.5 mm or more greater than the
diameter of the expanded connector, then the connector structure
200 may constrain the expansion of the balloon distal to the
connector by anywhere from 0.25 mm to about 0.5 mm depending on how
close to the end of the barrel portion 318 the connector structure
200 is located. This is illustrated by the difference in the
unconstrained diameter of balloon 302 (FIG. 8) and the constrained
diameter (FIG. 12). This constraint of balloon 302 by connector 200
is useful to reduce the diameter of the balloon 302 inside the
second conduit thereby reducing the risk of dilating the second
conduit with the balloon while simultaneously expanding the
connector.
[0106] Continuing with the present example, the connector may be
mounted 1.5 mm from the end of a 3.5 mm balloon wrapped (as
illustrated in FIG. 11) to a profile of 0.038. This system is
useful to join a larger first conduit 10 to a smaller second
conduit of about 2.5 mm in diameter with a resulting anastomosis
diameter of 2.25 mm to about 2.5 mm. When the balloon 302 is
pressurized to deploy this connector structure 200, the portion of
the balloon extending beyond the connector will typically have a
diameter of about 3.0 mm and a length of about 1.5 mm. In this
case, the short length of the distal end portion of the balloon
allows it to be inflated inside the 2.5 mm conduit, such that the
conduit takes on an oval shape over the 3.0 mm by 1.5 mm balloon
portion without being dilated or stretched by it.
[0107] As will be described herein, the system is introduced in a
substantially axial direction into the second conduit (see, FIG.
21), and subsequently rotated to a radial direction with respect to
the second conduit (see, FIG. 23). For this type of installation,
the diameter of the connector structure 200 and the distance from
the distal members 218 to the end of the balloon should both be
shorter than the diameter of the second conduit. The distal members
218 are less likely to snag the back wall of the second conduit if
the diameter of the connector structure at the distal members 218
is at least 0.01 inches smaller than the diameter of the
pressurized second conduit. The diameter of the connector structure
at the distal members 218 depends, in part, on the length of the
distal members 218 and on the diameter of the balloon 302 under the
connector. The length of the distal members 218 necessary to have
them engage the tissue of the second conduit results in them adding
about 0.5 mm to the diameter of the balloon distal end.
Consequently, the wrapped balloon 302 may have a diameter at least
0.5 mm less than the inner diameter of the second conduit, and
preferably 1-1.5 mm less. The distal members 218 are also less
likely to be pushed out of the aperture 22 in the second conduit
when the system is rotated to an orientation perpendicular to the
second conduit if the distance from the distal members 218 to the
distal end portion of the balloon 302 is less than the diameter of
the second conduit.
[0108] It is contemplated that the balloon 302 may be configured
for removal and reattachment with respect to the shaft portion
304/306 (see, FIG. 8). According to one embodiment, the catheter
shafts 304 may include a junction 370 in a region just proximal to
the balloon 302 which would allow the shaft portions proximal to
the junction 370 and the shaft portions distal to the junction 370
to be separated and reconnected, repeatedly, as required.
Similarly, the catheter shaft 306 may include a junction 372 in a
region just proximal to the balloon 302 which would allow the shaft
portions proximal to the junction 372 and the shaft portions distal
to the junction 372 to be separated and reconnected. These
junctions 370/372 may be achieved by a pair of luer fittings to
connect the two lumens 312 and 316 of the shafts 304/306. A benefit
of this construction when providing an anastomosis between a first
and second conduit is to reduce the size and weight of the
apparatus attached to the first conduit prior to performing the
connection to the second conduit. This arrangement may be
beneficial in cases where a connector is being used on each end of
a conduit so that the connection apparatus for use at the first end
is not in the way of the connection apparatus at the second end
while the anastomosis at the first end is being made. This
arrangement may also be beneficial in loading the first conduit
onto the connector structure.
The Nosecone Assembly
[0109] The nosecone assembly 400 is illustrated in FIGS. 13-14, and
may comprise an elongated tubular shaft 402, a nosecone balloon
404, and an indicator wire 406. The tubular shaft 402 may be made
of nitinol, a composite braid tubing, a metal hypotube (e.g.,
steel), or of a polymer extrusion such as nylon. According to one
embodiment, the tubular shaft 402 has an outer diameter of
approximately 0.014 inches and an inner diameter of approximately
0.010 inches. The nosecone balloon 404 may be fabricated of a
number of materials such as, e.g., polyethylene, polyolefin
copolymers, ethylene vinyl acetate, urethane, or other materials
suitable for manufacturing an inflatable balloon. It is preferable
that a relatively soft material be used (such as those described
above) for the requirements of the application described herein.
The nosecone balloon 404 may comprise a distal tapered portion 408
and a proximal portion 410. The proximal portion 410 may be
attached to the tubular shaft 402. The internal cavities of the
distal tapered portion 408, the proximal portion 410, and the lumen
412 of the tubular shaft 402 are preferably in fluid communication.
An indicator wire 406 is attached to the distal tip 414 of the
nosecone balloon 404, and extends proximally through the tubular
shaft 402. In a preferred embodiment, the wire 406 is set in place
by means of an adhesive 407. The nosecone assembly 400 is flexible,
and capable of bending to an angle of about 100 degrees or more
with respect to the longitudinal axis thereof (see, e.g., FIG.
23).
[0110] The nosecone balloon 404 is illustrated in its "introduction
configuration" or folded configuration in FIG. 14. FIG. 13
illustrates the nosecone balloon 404 in its "removal configuration"
or unfolded configuration. In the introduction configuration, the
proximal portion 410 is folded back in a concave manner, and
defines an annular recess 420 for receiving the connector structure
200 or the like, as will be described in greater detail herein.
Expanding the nosecone balloon 404 is typically achieved by
introducing fluid into the nosecone balloon 404 from the tubular
shaft 402, thereby changing the configuration of the nosecone
balloon 404 from the introduction configuration to the removal
configuration, i.e., from the folded configuration of proximal
portion 410 depicted in FIG. 14 to the unfolded condition depicted
in FIG. 13. When the balloon moves from the introduction
configuration of FIG. 14 to the removal configuration of FIG. 13,
the nosecone balloon 404 defines a smaller outer dimension. and
smooth proximal surface to facilitate removal of the nosecone
balloon 404 from the second conduit and the connector structure
200, as will be described in greater detail herein.
[0111] The indicator wire 406 moves within the tubular shaft 402
with the distal tip portion 414. Consequently, a proximal length of
the indicator wire 406 may extend out of the shaft a short length
406a when the nosecone balloon 404 is folded (FIG. 14). When the
nosecone balloon 404 is expanded (unfolded), distal tip 414 and the
distal tapered portion 408 advance distally with respect to the
tubular shaft 402 (see also, FIGS. 21-22). When the distal tip
portion 414 advances distally, the proximal length 406a of wire 406
is drawn into the tubular shaft 402 (FIG. 13). In this manner, the
indicator wire 406 provides a visual indication that the nosecone
balloon 404 has unfolded. During the distal advancement of distal
tapered portion 408, the tubular shaft 402 remains stationary.
Alternatively, the nosecone could be advanced mechanically, e.g.,
by advancing a substantially rigid indicator wire. According to
another embodiment, the nosecone assembly may be manufactured
without an indicator wire.
[0112] The dimensions of the nosecone balloon 414, i.e., the
diameter and length, are selected in order to cover the distal
members 218 of the connector structure 200 during introduction of
the apparatus into the second conduit.
[0113] While filled with expansion fluid in the unfolded condition
of FIG. 13, the nosecone balloon 404 may define a degree of
rigidity. Typically, the rigidity is proportional to the pressure
of the expansion fluid; the balloon 404 becomes more flexible as
more fluid is drained from the balloon 404.
[0114] The tubular shaft 402 is configured to be axially received
in the lumen 312 of balloon catheter 300. FIG. 1 illustrates the
nosecone assembly 400 positioned with respect to balloon catheter
300. The nosecone balloon 404 is folded about the expansion balloon
302 and the connector structure 200. In the folded condition, the
distal members 218 of the connector structure 200 are covered, so
that the periphery of the aperture in the second conduit does not
snag on these members as the connector is inserted into this
aperture, as will be described in greater detail herein.
[0115] According to another embodiment of the invention, the
nosecone balloon 404 may be substituted by a solid cap, which
covers the distal members during insertion into the aperture of the
second conduit. Additional details of the nosecone structure are
described in Swanson et al. U.S. Pat. No. 6,113,612, incorporated
by reference in its entirety herein. Additional embodiments of the
nosecone assembly are described herein with respect to FIGS.
31-43.
[0116] The first conduit 10 is subsequently mounted to the
connector structure 200 about an aperture 12 made in the first
conduit 10. The first conduit 10 may be natural body tissue (e.g.,
a length of the patient's saphenous vein harvested for use as a
graft, a partly severed internal mammary artery, etc.), an
artificial graft (e.g., as shown in Goldsteen et al. U.S. Pat. No.
5,976,178, or published PCT patent application WO 98/19632, both of
which are hereby incorporated by reference herein in their
entireties), or a combination of natural and artificial conduits
(e.g., a length of natural conduit disposed substantially
concentrically inside a length of artificial conduit).
[0117] An opening 12 may be made in the first conduit 10 at a
location spaced from the end portion 14 of the conduit 10. The size
of the opening 12 in the first conduit 10 is an important
consideration. (It is understood that the description concerning
opening 12 is applicable to the opening 22 in second conduit 20.)
If the opening is too large, then a satisfactory hemodynamic seal
may not be created between the two conduits. Conversely, if the
opening is too small, one or more of the following undesirable
effects may occur: the conduit wall may tear excessively when the
connector 200 is enlarged, or the conduit may constrict enlargement
of the connector. (When making the opening in the second conduit,
the opening may not permit the nosecone 400 to be inserted
therethrough if it is too small.) Which of these above effects
occurs is determined in part by tissue quality, the dimensions of
the apparatus being used, and the inflation pressure of the
balloon.
[0118] The opening in the conduit should preferably be sized such
that enlargement of the connector structure 200 does not cause
significant additional tearing of the wall to expand the periphery
of the opening. Rather, it is generally desirable that the
expansion of the opening to accommodate the enlarged connector is
achieved within the elastic expansion range of the conduit wall.
The elastic expansion is important since the distal members 218
engage the conduit wall as the connector structure expands. If the
conduit wall tears a significant amount, e.g., at the locations of
engagement with the distal members 218 (rather than elastically
expanding), it is possible that the desired tension created in the
wall between the distal members 218 would be relieved, which may
prevent the creation of a seal between the conduits being joined.
As an example, the diameter of the aperture in the conduit should
be between about 0.25 to about 1.0 mm smaller than the expanded
diameter of the connector. This will preferably allow the
elasticity of the conduit tissue to assist in creating a seal
between the conduits as they are stretched to the diameter of the
expanded connector.
[0119] The openings in the conduits can be made by cutting,
mechanical dilation, or by a combination of both. According to a
preferred embodiment, the initial opening is made by cutting the
conduit with a 20 gauge needle and then dilating the opening using
a dilator between 2.0 and 2.5 mm to prepare an opening for a 2.25
mm connector. The size of the initial cut and the size of the
dilator may be selected based upon the elastic characteristics of
the conduits being used. In this case, the opening may recoil back
to a range of about 1.5 to 2.0 mm after the dilator is withdrawn.
An advantage of the cutting and dilating procedure is that the
physician is able to effectively reduce the influence of the
possible variations in conduit wall elasticity by dilating to a
diameter similar to the connector size. Thus the amount of recoil,
as a function of the elasticity of the conduit wall, is irrelevant
to sizing the opening.
[0120] According to another embodiment, an initial opening is made
by piercing the conduit with a 20 gauge needle, and then dilating
the opening by inserting and then expanding a 2.0 to 2.5 mm
balloon. This embodiment provides the advantage of applying uniform
dilating force from both the inside and the outside of the conduit.
The use of balloon expansion reduces the risk of dissecting the
layers of the conduit since a minimum of radial force is applied.
This is particularly helpful in the case of diseased conduits,
where the inner layer is typically harder than the outer layer. The
harder inner layer may resist the application of radial force more
strongly than the outer layer, which may result in the inner layer
peeling away from the outer layer. A balloon may minimize this
undesirable effect since the balloon is first introduced into the
initial opening with a reduced profile, and then is expanded. Due
to the resistance of the conduit wall, the balloon tends to expand
on both the inside and outside of the conduit, and counteracts any
unbalanced radial force that might separate the layers of the
conduit.
[0121] The opening in the conduit may also be created without a
dilation step. This may be particularly useful where the conduit is
diseased, and it is desired to reduce the risk of dissecting tissue
layers. In the absence of a dilation step, the elasticity of the
conduit wall may be reasonably estimated in order to cut an opening
of the proper size to receive the connector therethrough. According
to another embodiment, the opening in the conduit may be created by
a cutting instrument. In this case, the deflated conduit is
advanced a known distance into a scissors or semicircular cutter,
and then the conduit is cut to yield a hole of known diameter and
length.
[0122] According to yet another embodiment, a coring cutter
apparatus may be used to core an opening of known diameter in the
conduit wall. The coring apparatus is useful if the conduit is
stretched over the end of a loading sheath, or can be used with a
pressurized conduit, or with a vacuum port in the bore of the
cutter to support the wall of the conduit to be cut.
Transfer Sheath
[0123] A transfer sheath 600 and rod 603, illustrated in FIG. 15,
may assist in the mounting of the first conduit 10 onto the
apparatus 100, without compromising the delicate intima of the
first conduit 10. The transfer sheath 600 and rod 603 may be
fabricated from a low friction, biocompatible polymer such as,
e.g., polyethylene or polytetrafluoroethylene, or similar material.
The transfer sheath 600 may alternatively be made of metal, such
as, e.g., stainless steel. The rod 603 may be rigid or expandable,
as described below. The transfer sheath 600 may have an elongated
body portion 602 with a distal end portion 601 and an internal
lumen 606. A rod 603, having a tapered end portion 604, is sized to
be coaxially positioned within lumen 606 such that the tapered end
604 extends beyond the end of the lumen 606 of transfer sheath 600.
The tapered end portion 604 may be rigid or it may be configured to
expand and contract. For example, the tapered end portion 604 may
be configured to expand as large as the outer diameter of the
transfer sheath 600 for a smooth transition from the tapered end
portion 604 to the sheath body 602, and then be configured to
collapse to a smaller dimension to be retracted through internal
lumen 606. This allows the first conduit 10 to be loaded over the
transfer sheath 600, in the direction indicated by arrow A.
[0124] The transfer sheath 600 assists the physician by serving as
a sizing instrument. The outer diameter of the body portion 602 is
selected to accommodate the first conduit 10, such as a graft,
having a diameter which is compatible with the connector structure
200. For example, a first conduit that is too narrow will not be
able to receive the sheath 600 therethrough. Moreover, the internal
diameter of the first conduit should be sufficiently large to allow
for expansion of balloon 302 and connector structure 200 without
dilating the first conduit 10 during such expansion. Therefore,
body portion 602 of transfer sheath 600 has a diameter of about 3.5
mm, according to a preferred embodiment. The diameter of body
portion 602 may be fabricated with a different diameter, and
corresponding connector size, depending upon the specific clinical
indication of the graft size and desired anastomosis size.
[0125] Once the first conduit 10 is harvested, it is positioned
over transfer sheath 600. As illustrated in FIG. 16, the distal end
portion 14 of conduit 10 is positioned over the transfer sheath
600. Entry through the distal end portion 14 allows the remainder
of the conduit 10 to be free, which is useful, for example, when
the proximal end of the first conduit 10 is to be attached to
another vessel, such as the aorta of the patient. As illustrated in
FIG. 16, the tapered end portion 604 of rod 603 extends distally
from transfer sheath 600 to provide a smooth transition as transfer
sheath 600 and rod 603 are advanced within the lumen of first
conduit 10 in direction indicated by arrow B.
[0126] When the transfer sheath is positioned at the location 11
where opening 12 is to be made in first conduit 10, rod 603 is
withdrawn proximally, while transfer sheath 600 remains in
position. The wall of the first conduit 10 is held taut over the
distal end 601 of the transfer sheath 600. Opening 12 is made in
the wall of first conduit 10. This opening 12 can be created by a
combined cutting and dilating procedure as described herein.
[0127] As illustrated in FIG. 17, the balloon catheter 300,
nosecone assembly 400, and connector structure 200 are advanced
through the internal lumen 606 of transfer sheath 600 to the
opening 12.
[0128] FIG. 18 illustrates that nosecone assembly 400 is advanced
until connector structure 200 partially protrudes through the
opening 12. Subsequently, the first conduit 10 is retained in
position (e.g., with an atraumatic grasping instrument), and the
sheath 600 is removed by passing the transfer sheath 600 coaxially
over the balloon catheter 300.
[0129] With continued reference to FIG. 18, the periphery of an
opening 12 in first conduit 10 is placed about the connector
structure 200. More particularly, conduit 10 is positioned so that
proximal members 222 penetrate and pass through the side wall of
the graft conduit 10 (e.g., as a result of compressing the graft
against the fingers by tool 440 such as the vein piercing tool
described in Logan et al. U.S. patent application Ser. No.
09/587,112, filed Jun. 2, 2000, and incorporated by reference in
its entirety herein, thereby forcing the fingers to pierce through
the graft wall). The sharpened free ends 224 of members 222
facilitate penetration of conduit 10 by members 222. The blunt rear
surfaces of enlarged free end portions 224 resist withdrawal of
members 222 from conduit 10 after members 222 have penetrated the
conduit. The graft may be additionally or alternatively directly
sutured to the connector body. If the alternative of suturing graft
10 to the connector structure 200 is used, then the second cell
portion 204 of the connector may not need radially outwardly
deflectable members 222 for engagement of the graft conduit.
Alternatively, the first conduit 10 may be secured to the connector
structure 200 with glues, clips, or other connector elements.
[0130] As an alternative to securing first conduit 10 to connector
structure 200 after balloon catheter 300 has been associated with
the connector, balloon catheter 300 may be installed in connector
structure 200 after the first conduit 10 has been secured to the
connector structure.
The Locating Ring
[0131] A later step in preparing the first conduit 10 for
anastomosis may be to place a locating ring 500 about the periphery
of the opening, as illustrated in FIG. 1. Further details of the
locating ring 500 are illustrated in FIGS. 19-20. Locating ring 500
may be fabricated in a toroidal or serpentine ring configuration
from silicone with high elastic strength. The locating ring 500 may
also be provided with apertures 502 extending radially through the
material for receiving proximal members 222 therein once the
locating ring 500 has been placed about the periphery of the
aperture 12 in the first conduit 10 as illustrated in FIG. 1. Use
of the locating ring 500 is optional, and may be omitted from the
procedure as determined by the physician.
[0132] The locating ring 500 provides benefits to the procedure in
accordance with the invention. The locating ring 500 provides a
visual indication of the edge of the aperture 12 of the first
conduit 10. This assists the physician when delivering the first
conduit 10 to the anastomosis site, in order to properly align the
apertures in the first and second conduits prior to deploying the
connector. The locating ring 500 also provides some protection to
the second conduit by shielding the tissue of the second conduit
from the proximal members 222 when the apparatus is being
introduced into the second conduit. In addition, the locating ring
500 provides an abutment surface or a stop to inhibit the proximal
members 222 from being axially introduced into the second conduit
when the tip of the balloon catheter 302 and the distal end of the
connector structure 200 are being introduced in the second
conduit.
[0133] Another embodiment of the locator ring is a structure which
surrounds the periphery of the aperture in the first conduit 10
about the proximal members 222 as locator ring 500 described
hereinabove, and is also removable from the first conduit 10 prior
to completion of the procedure. This embodiment of the locator ring
may have a clip structure (or "C"-shaped structure) having an
opening in the circumference to allow removal from the conduit.
According to another embodiment, the locator ring structure may be
substituted with a plurality of individual components which may be
attached one or more members 222. According to yet another
embodiment, the locator ring may be substituted by applying a color
marking to the periphery of the aperture to provide a visual
indication useful to the physician in aligning the first and second
conduits.
Operation of the Apparatus
[0134] FIGS. 21-24 illustrate a typical use of apparatus 100 to
deliver first conduit 10 for connection to an aperture 22 in a side
wall of second conduit 20, typically the patient's tubular body
conduit (e.g., a coronary artery requiring a bypass graft).
[0135] Aperture 22 is typically made in second conduit 20 in a
manner described herein above with respect to making the aperture
12 in the first conduit 10. The aperture 22 is typically made
downstream from an occlusion or lesion 30 in the second conduit 20.
As illustrated in FIG. 21, the nosecone balloon 404 of nosecone
assembly 400 may be gradually forced into the aperture 22 in a
direction substantially coaxial with the lumen 24 of the second
conduit 20. As the nosecone balloon 404 passes through the aperture
22, the annular space 420 defined by the inverted proximal tapered
portion 410 may shield the distal members 218 from snagging on the
tissue of the second conduit 20. As long as nosecone balloon 404
remains in the introduction configuration, a distal portion 406a of
indicator wire 406 may extend partially beyond the proximal end
portion of tubular shaft 402. Locating ring 500 may provide a
visual indication that aperture 12 of first conduit 10 and aperture
22 of second conduit 20 are approximated. Locating ring 500 may
also inhibit proximal members 222 from passing through the aperture
22 of second conduit 20.
[0136] The physician may determine if the connector structure 200
has been properly positioned with respect to the apertures 12 and
22. As shown in FIG. 22, the next step in the use of apparatus 100
may be to inflate nosecone balloon 404 by introducing fluid into
tubular shaft 402 and balloon 404. As the nosecone balloon 404
expands (i.e., moves from the introduction to the removal
configuration), the distal tip 414 moves distally into the lumen 24
of the second conduit 20, and the proximal tapered portion 410
returns to an unfolded condition similar to that shown in FIG. 19.
In the unfolded condition, the distal members 218 of connector
structure 200 are exposed within the lumen 24 of the second
conduit. The distal advancement of distal tip portion 414 also
advances the indicator wire 406 into the tubular shaft 402. The
position of the indicator wire 406 with respect to the tubular
shaft 402 thus provides a visual indication that the nosecone
balloon 414 has successfully moved to the removal
configuration.
[0137] A next step in the use of apparatus 100 is to drain the
expansion fluid from the nosecone balloon 404, as shown in FIG. 23.
The nosecone balloon 404 is flexible, which allows the portion of
the apparatus 100 comprising balloon catheter 300, connector
apparatus 200, and a proximal portion of nosecone assembly 400 to
be turned to a position at approximately a 90 degree angle with
respect to the lumen 24 of the second conduit 20. As described
above, the axial distance 250 between the distal members 218 and
the proximal members 222 when the connector structure 200 is in the
unenlarged condition is sufficient to prevent the distal members
218 from being moved out of the aperture 22 of the second conduit
20 during rotation to the perpendicular orientation. As described
hereinabove, the distance between the connector apparatus 200 and
the distal end of the balloon 302 is minimized to prevent dilating
the inner lumen 24 of the second conduit 20 when the balloon 302 is
inflated.
[0138] A next step in the use of apparatus 100 is to inflate
balloon 302 as shown in FIG. 24. In order to create the greater
deflection of the ends of the connector structure 200 as described
above with respect to FIGS. 5 and 10, balloon 302 has an inflated
diameter larger than the connector structure 200 to enlarge the
connector structure 200. Inflation of balloon 302 causes the
connector structure 200 to annularly enlarge by enlarging cells 202
(defined by members 230a/230b) and 204 (defined by members
230b/230c) in the annular direction. In addition, the proximal
portion 208 and distal portion 206 of connector structure 200 are
deflected radially outwardly beyond the medial portion 207 of
connector structure 200. These two actions, i.e., overall annular
enlargement of connector structure 200 and relatively greater
enlargement of portions 206 and 208, decrease the axial spacing
between portions 202 and 204, and more particularly decreases the
axial spacing 250 between distal members 218, on the one hand, and
proximal members 222, on the other hand (FIG. 5). The free ends 220
of distal members 218 preferably penetrate the side wall of second
conduit 20 to help ensure that first conduit 10 is securely
attached to the second conduit 20 and remains open where it
connects to second conduit 20. Consequently members 218 and 222 are
positioned to better engage the tissue of the conduits at the
perimeter of the aperture 22 in the second conduit 20 being joined.
The approximation of members 218 and 222 also helps to draw the
edges of the two conduits together to create a good seal
therebetween. With this connector structure, the seal between the
conduits is typically a lap joint between the two sets of prongs,
wherein the edge of the hole in one of the conduits sits under the
edge of the hole in the other conduit as the connector structure is
expanded; or alternatively a butt joint may be formed between the
two vessels.
[0139] Assuming that the connector structure 200 is approximately
properly positioned relative to the side wall of second conduit 20
prior to inflation of balloon 303, the connector structure 200 is
effectively self-centering on the second conduit side wall as the
balloon 302 is inflated. Moreover, since the connector structure
200 is positioned adjacent the distal end portion of balloon 302,
it is possible to position the connector structure 200 about the
wall of the second conduit 20 without dilating or damaging the
opposite wall of the second conduit 200 with the balloon 302.
[0140] A next step in the use of apparatus 100 is to deflate
balloon 302 and withdraw all of the elements 300 and 400 (e.g., by
pulling them proximally out of the first conduit 10). Subsequently,
the distal end portion 14 of the first conduit 10 may be tied off
with a ligature 50, to direct flow from the first conduit 10 into
the second conduit 20. This leaves the side wall of first conduit
10 connected to the side wall of second conduit 20 by enlarged
connector structure 200 as shown in FIGS. 25-27. In particular, in
this example connector structure 200 provides a side-to-side
anastomosis between a first conduit 10 and a second conduit 20.
Body fluid from first conduit 10 is able to flow into second
conduit 20 via this connection. Connector 200 presses the aperture
12 through the side wall of the first conduit 10 radially outward
against the aperture 22 through the side wall of second conduit 20
all the way around the apertures 12/22, thereby preventing body
fluid from leaking out of conduits 10 and 20. Connector structure
200 also prevents first conduit 10 from pulling away from the side
wall of second conduit 20.
[0141] According to another embodiment of the invention, the
apparatus described herein may be useful in connection with
creating an anastomosis between two body conduits in-situ. As
illustrated in FIG. 28, the physician may wish to form an
anastomosis between first conduit 10 and second conduit 20, wherein
both conduits are relatively adjacent to one another, and it is not
necessary to move either conduit a great distance to perform the
anastomosis. Under these circumstances, the apparatus 100 may be
introduced into first conduit 10, in the manner described above
with respect to FIGS. 16-18. More particularly, transfer sheath 600
may be introduced percutaneously into the patient's vascular system
and advanced to the anastomosis site, and an opening 12 is made at
the anastomosis site. The nosecone assembly 400, connector
structure 200, and balloon catheter 300 are subsequently introduced
to the anastomosis site within the lumen of the transfer sheath
600. Once the nosecone assembly 400 protrudes from the opening 12
in the first conduit 10, the free ends 222 of connector structure
200 are secured about the periphery of opening 12. A locating ring
500 may be used. An opening 22 is made in the second conduit 20 as
described above. The anastomosis is performed substantially as
described above with respect to FIGS. 21-25.
[0142] According to another embodiment, the apparatus described
herein may be useful for creating a series of anastomoses along the
length of a single conduit or between two conduits. As illustrated
in FIG. 29, the procedure described herein may be performed at a
first anastomosis site 700. After the connector structure 200 is
deployed, the nosecone assembly 400 and the balloon catheter 300
are withdrawn; however, the first conduit 10 remains open and is
not tied off as described above with respect to FIG. 25. According
to this embodiment, a second connector structure 200, along with
the balloon catheter 300 and nosecone assembly 400 are positioned
within the first conduit 10 at a second anastomosis location 702.
The second anastomosis is performed substantially as described
herein.
[0143] According to yet another embodiment, the apparatus described
herein also be useful for making an end-to-side anastomosis. As
illustrated in FIG. 30, the connector structure 200 is attached to
the end portion 15 of the first conduit 10, rather than about the
periphery of an opening 12 made in the side wall of the first
conduit 10. The connector structure 200, the balloon catheter 300,
and the nosecone assembly 400 are loaded onto the first conduit
substantially as described above with respect to FIGS. 16-18, with
the following differences described herein. The transfer sheath 600
is advanced within the lumen of the first conduit 10 until it
protrudes slightly from the end portion 15. The connector structure
200, balloon catheter 300, and the nosecone assembly 400 are
subsequently advanced within the lumen 606 of the transfer sheath
600 until members 222 protrude from the end portion 15 of the first
conduit 10. (Transfer sheath 600 may then be removed.) The free end
portions 224 are used to pierce the wall of the first conduit 10
about the end portion 15. A locating ring 500 may be used. The
anastomosis procedure is performed substantially as described
herein with respect to the side-to-side anastomosis procedure.
[0144] According to still another embodiment, the apparatus
described herein may also be useful in making an anastomosis
between a first vessel, such as a graft conduit, e.g., SVG, and the
aorta or other arterial blood source.
[0145] Another embodiment of the nosecone assembly is illustrated
in FIGS. 31-35, and is generally denoted by reference number 450.
Nosecone assembly 450 may comprise an elongated tubular shaft 452,
and a nosecone 454. The tubular shaft 452 may be substantially
similar to tubular shaft 402, described hereinabove. However,
tubular shaft 452 may be a solid member. The nosecone 454 may
comprise a distal tip portion 456, which is attached to the tubular
shaft 452. A plurality of cone sections 458 extend from the tip
portion 456, and are each individually, flexibly attached to the
distal tip portion 456.
[0146] FIG. 31 illustrates the nosecone 454 in its introduction
configuration, which facilitates the introduction of the nosecone
assembly 450 and the connector structure 200 into the second
conduit 20. In this configuration, the cone sections 458 extend
both proximally and radially outward from distal tip portion 456.
The cone sections 458 define an annular space 459 for receiving the
connector structure 200. FIG. 32 illustrates the nosecone 454 in
the compacted, removal configuration, which facilitates the removal
of the nosecone assembly from the second conduit 20. In the removal
configuration, the cone sections 458 extend distally from the tip
portion 456. Preferably, the cone sections 458 may be positioned
closer together in the removal configuration to define a lower
profile. The dimensions of the nosecone 454, i.e., the diameter and
length, are selected in order to cover the distal members 218 of
the connector structure 200 during introduction of the apparatus
into the second conduit.
[0147] FIGS. 33-35 illustrate a typical use of the nosecone
assembly 450. As illustrated in FIG. 33 (which corresponds to FIG.
21, above), the nosecone 454 is used to introduce the connector
structure 200 and the balloon catheter 300 into the opening 22 in
the second conduit. Nosecone 454 is in the introduction
configuration, and shields the first members 218 (not visible in
FIG. 33). As illustrated in FIG. 34 (which corresponds to FIG. 22,
above), nosecone 454 is advanced into the lumen 24 of second
conduit 20, thereby exposing the first members 218. Such
advancement may be achieved by remotely advancing tubular member
452. FIG. 35 illustrates the condition in the procedure after
balloon 302 has been expanded to enlarge connector structure 200
and attach first conduit 10 (illustrated with dashed lines) to
second conduit 20. Nosecone 454 may be removed from the operative
site by proximally withdrawing tubular shaft 452. When the cone
sections 458 comes in contact with the balloon 302, they are
deflected distally to the removal configuration shown in FIG.
32.
[0148] Yet another embodiment of the nosecone assembly is
illustrated in FIGS. 36-39, and is generally denoted by reference
number 460. Nosecone assembly 460 may comprise an elongated tubular
shaft 462, and a nosecone 464. The tubular shaft 462 may be
substantially similar to tubular shaft 402, described hereinabove.
The nosecone 464 may comprise a collapsible cone portion 466, a
flexible distal tip portion 465, and a proximal portion 467. The
proximal portion 467 is configured for longitudinal movement within
the lumen of tubular shaft 462. The distal tip portion 465 may be
biased to define a bend, or "knee" portion between the proximal
portion 467 and the cone portion 466.
[0149] FIG. 36 illustrates the nosecone 464 in its introduction
configuration, which facilitates the introduction of the nosecone
assembly 460 and the connector structure 200 into the second
conduit 20. In this configuration, the cone portion 466 extends
both proximally and radially outward from distal tip portion 465.
The cone portion 466 defines an annular space 469 for receiving the
connector structure 200. FIG. 37 illustrates the nosecone 464 in
the compacted, removal configuration, which facilitates the removal
of the nosecone assembly from the second conduit 20. In the removal
configuration, the proximal portion 467 is withdrawn proximally,
and the distal tip portion 465 bends against its bias towards
parallelism with the lumen of the tubular shaft 462. The cone
portion 466 is collapsed and also withdrawn into the tubular shaft
462.
[0150] FIGS. 38-39 illustrate a typical use of the nosecone
assembly 460. As illustrated in FIG. 38 (which corresponds to FIG.
21, above), the nosecone 464 is used to introduce the connector
structure 200 and the balloon catheter 300 into the opening 22 in
the second conduit. Nosecone 464 is in the introduction
configuration, and shields the first members 218 (not visible in
FIG. 38). Nosecone 464 may be advanced into the lumen 24 of second
conduit 20, as illustrated in FIG. 34, above. FIG. 39 illustrates
the condition in the procedure after balloon 302 has been expanded
to enlarge connector structure 200 and attach first conduit 10
(illustrated with dashed lines) to second conduit 20. Nosecone 464
may be removed from the operative site by proximally withdrawing
proximal portions 467 into tubular shaft 462. The distal tip
portion 465 will straighten as it is withdrawn into tubular shaft
462, which in turn will cause the cone portion 466 to collapse to a
size which can also be removed into tubular shaft 462.
[0151] Still another embodiment of the nosecone assembly is
illustrated in FIGS. 40-43, and is generally denoted by reference
number 470. Nosecone assembly 470 may comprise an elongated tubular
shaft 472, and a nosecone 474. The tubular shaft 472 may be
substantially similar to tubular shaft 402, described hereinabove.
The nosecone 474 is fabricated from a highly elastic material that
may be expanded from a substantially narrow cylindrical
configuration to substantially tapered configuration upon the
introduction of expansion fluid. Upon draining the expansion fluid,
nosecone 474 returns to the narrow initial configuration.
[0152] FIG. 40 illustrates nosecone 474 in its introduction
configuration, which facilitates the introduction of nosecone
assembly 470 and connector structure 200 into second conduit 20. In
this configuration, a distal portion 475 extends both proximally
and radially outward from distal tip portion 476. In this
configuration, nosecone 474 defines an annular space 479 for
receiving the connector structure 200. A central longitudinal
member 477 may be optionally provided for additional stability. A
lumen 478 allows expansion fluid to be introduced into nosecone 474
to expand it to the configuration shown in FIG. 40. FIG. 41
illustrates nosecone 474 in the compacted, removal configuration,
which facilitates the removal of the nosecone assembly from second
conduit 20. In the removal configuration, nosecone 474 elastically
returns to a narrow configuration having approximately the same
profile as tubular shaft 472.
[0153] FIGS. 42-43 illustrate a typical use of nosecone assembly
470. As illustrated in FIG. 42 (which corresponds to FIG. 21,
above), nosecone 474 is used to introduce connector structure 200
and balloon catheter 300 into opening 22 in the second conduit.
Nosecone 474 is in the introduction configuration, and shields
first members 218 (not visible in FIG. 42). Nosecone 474 may be
advanced into the lumen 24 of second conduit 20, as illustrated in
FIG. 34, above. FIG. 43 illustrates the condition in the procedure
after balloon 302 has been expanded to enlarge connector structure
200 and attach first conduit 10 (illustrated with dashed lines) to
second conduit 20. Nosecone 474 may be removed from the operative
site by draining the expansion fluid and allowing nosecone 474 to
return to the configuration of FIG. 41, and by subsequently
withdrawing tubular shaft 472 and nosecone 474.
[0154] It will be understood that the foregoing is only
illustrative of the principles of this invention, and that various
modifications can be made by those skilled in the art without
departing from the scope and spirit of the invention. For example,
the number and shape of the annularly enlargeable connector cells
can be different from what is shown in the drawings herein. The
number of axially adjacent rows of annularly enlargeable cells can
be different from the numbers of such rows that are shown herein
(i.e., two rows of cells in the case of connectors 200). For
example, a connector may have one, two, three, four, or more rows
of cells. The cells may have any of many forms, depending on the
desired degree of expansion and final radial strength. The number
of cells, the number of rows of cells, the size of the cells, and
the geometry of the cells can all be selected to control the
expansion, strength, and sizing of the finished connector. The
number and shape of the radially outwardly deflectable connector
members can also differ from what is shown herein.
[0155] Although considerable variation in the connectors of this
invention is thus possible and contemplated, in general such
connectors comprise a unitary structure disposed annularly about a
longitudinal axis. It will be appreciated that, in general, the
structure of the connectors of this invention is such that radial
enlargement of the connector reduces the axial spacing between the
above-mentioned first and second members. This helps the connector
draw together in a fluid-tight way the two body fluid conduits that
are to be connected by the connector. In the embodiment shown in
FIGS. 2-5, for example, annular enlargement of cells defined by
members 230a/230b/232a/236b and 230b/230c/234b/238c causes a
decrease in the axial spacing between members 218, on the one hand,
and members 222, on the other hand. The above-described axial
shortening of the connector advantageously applies compressive
forces (for sealing) to the body fluid conduits being
connected.
[0156] In general, most of the deformation of the connectors of
this invention is preferably plastic strain and therefore
permanent. The deformation thus referred to includes both the
above-described radially outward deflection of members like 218 and
222, etc., and the above-described radial enlargement of the
connector.
[0157] The radially outwardly deflectable members or portions of
the connector may also include barbs, hooks, spikes, loops, clips,
or suture rings.
[0158] The connectors of this invention may be constructed so that
different portions of the connector annularly enlarge in response
to different amounts of applied annular enlargement force. For
example, in the embodiment shown in FIGS. 2-5, the portions of the
structure associated with lengths 212 and 216 in FIG. 2 may be made
so that they are less resistant to inflation of a balloon 302
inside the connector 200 than portions of the structure associated
with length 214. In an application of the type shown in FIGS. 2-5
this causes these less resistant portions to annularly enlarge by
deflecting radially out inside second conduit 20 before the
remainder of the connector begins to significantly annularly
enlarge. This early response of the less resistant portions inside
second conduit 20 may help to ensure that the connector does not
slip out of engagement with second conduit 20 during annular
enlargement of the connector 200. This technique of making
different portions of the connector with different strengths can be
used to provide any sequence or phasing of annular enlargement of
various portions of the connector. Alternatively or additionally,
the connector can be shaped, molded, or phased in any desired way
by providing a balloon structure 302 which is shaped, molded, or
phased in that way. For example, balloon structure 302 may comprise
two or more separately inflatable balloons of the same or different
inflated circumferential size. Two such balloons may be axially
displaced from one another inside the connector so that axially
different portions of the connector can be annularly enlarged at
different times and/or by different amounts.
[0159] Radiologically (e.g., x-ray) viewable markers can be used
anywhere on the connectors 200 and/or delivery apparatus (e.g., 300
or 400) or locating ring 500 of this invention to facilitate
radiologic observation of the proper placement and deployment of a
connector in a patient if the connector-utilizing procedure is such
that more direct visual observation is not possible or sufficient.
One way to enhance the radiologic viewability of connectors in
accordance with this invention is to make them from clad tubing.
Clad tubing has two (or more) substantially concentric layers of
metal, each with a desired property. For example, clad tubing may
have a tantalum layer over a stainless steel layer. The tantalum
layer provides radiodensity, thereby making a connector 200 that is
cut from this material radiologically viewable. The stainless steel
layer provides rigidity to the connector. The medial section can be
ground to reduce the thickness ratio to favor the tantalum. This
improves the ability for balloon expansion. Although connector 200
may thus be made of two or more layers of different materials, the
tube and the connector are still accurately described as unitary,
one-piece, or integral. As an alternative to using clad tubing, the
connector may be plated with a radiologic material to give it a
desired radiodensity. Another example of a material suitable for
radiologic layer is platinum.
[0160] The connectors of this invention may also be made of a
super-elastic material such as nickel-titanium ("nitinol"), which
would allow a similar geometry as stainless steel to self-deploy or
actuate in-vivo.
[0161] It will be appreciated that the fact that the connectors of
this invention can be initially relatively small in circumference,
and that they can be remotely controlled to position them in the
patient and to then annularly expand them for final deployment,
facilitates use of these connectors and associated apparatus at
remote and/or inaccessible locations in a patient. For example, a
connector of this invention may be delivered into and installed in
a patient (using apparatus 300, 400) through relatively small
instrumentation such as laparoscopic apparatus, a cannula, or an
intraluminal catheter. Thus a connector and associated apparatus
(e.g., apparatus 300, 400) of this invention can be used in any of
the procedures mentioned earlier in this specification, and in
particular in procedures and with other elements shown in any of
above-mentioned references WO 98/16161, U.S. Pat. No. 5,976,178,
U.S. Pat. No. 6,120,432, WO 98/55027, and U.S. Pat. No. 6,475,222.
Alternatively, the connector and/or apparatus (e.g., apparatus 300,
400) of this invention can be used in more traditional or
conventional surgical procedures or in other, known, less invasive
or minimally invasive procedures. As just some examples of possible
uses of the connectors and apparatus of this invention, they can be
used to perform an anastomosis to a beating or still heart without
the use of sutures or direct access.
[0162] Among the advantages of the invention are that it eliminates
suturing and reduces the time required to produce an anastomosis.
In major circulatory system repair procedures such as cardiac
bypass procedures, this can reduce cardiopulmonary pump time, which
is of great benefit to the patient. The invention provides improved
flow dynamics, e.g., from a graft to the coronary artery. The blood
entrance angle can be engineered into the connector geometry rather
than relying on suture skill or technique. The invention eliminates
possible suture injury to conduits. At the high stress site of an
anastomosis sutures are eliminated. The connector and a graft can
be delivered percutaneously, e.g., as in several of the references
that are mentioned above. Direct access required for suturing is
eliminated. An anastomotic connection can be made to a beating
heart.
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