U.S. patent application number 10/205288 was filed with the patent office on 2002-12-12 for minimally invasive revascularization apparatus and methods.
This patent application is currently assigned to St. Jude Medical ATG, Inc.. Invention is credited to Baker, Matthew W., Berg, Todd A., Boldenow, Gregory A., Galdonik, Jason A., Hindrichs, Paul J., Peterson, Alex A., Prigge, Christopher M., St. Germain, Jon Patrick, Sullivan, Daniel J., Swanson, William J., Thome, Scott P., Wahlberg, Mark D..
Application Number | 20020188302 10/205288 |
Document ID | / |
Family ID | 22688678 |
Filed Date | 2002-12-12 |
United States Patent
Application |
20020188302 |
Kind Code |
A1 |
Berg, Todd A. ; et
al. |
December 12, 2002 |
Minimally invasive revascularization apparatus and methods
Abstract
A bypass graft conduit is installed in the circulatory system of
a patient using apparatus which facilitates performing most or all
of the necessary work intraluminally (i.e., via lumens of the
patient's circulatory system). A guide structure such as a wire is
installed in the patient via circulatory system lumens so that a
portion of the guide structure extends along the desired path of
the bypass conduit, which bypass conduit path is outside the
circulatory system as it exists prior to installation of the bypass
graft. The bypass graft is then introduced into the patient along
the guide structure and connected at each of its ends to the
circulatory system using connectors that form fluid-tight annular
openings from the bypass graft lumen into the adjacent circulatory
system lumens. The guide structure is then pulled out of the
patient.
Inventors: |
Berg, Todd A.; (Plymouth,
MN) ; Sullivan, Daniel J.; (Medina, MN) ;
Baker, Matthew W.; (Minneapolis, MN) ; Hindrichs,
Paul J.; (Plymounth, MN) ; Boldenow, Gregory A.;
(St. Michaels, MN) ; Galdonik, Jason A.; (St.
Louis Park, MN) ; Wahlberg, Mark D.; (St. Paul,
MN) ; Prigge, Christopher M.; (Minnetonka, MN)
; Peterson, Alex A.; (Maple Grove, MN) ; St.
Germain, Jon Patrick; (Elk River, MN) ; Swanson,
William J.; (St. Paul, MN) ; Thome, Scott P.;
(St. Cloud, MN) |
Correspondence
Address: |
Robert R. Jackson
FISH & NEAVE
1251 Avenue of the Americas
New York
NY
10020
US
|
Assignee: |
St. Jude Medical ATG, Inc.
Maple Grove
MN
|
Family ID: |
22688678 |
Appl. No.: |
10/205288 |
Filed: |
July 23, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10205288 |
Jul 23, 2002 |
|
|
|
09187364 |
Nov 6, 1998 |
|
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Current U.S.
Class: |
606/108 |
Current CPC
Class: |
A61M 25/0082 20130101;
A61B 17/32053 20130101; A61M 25/0068 20130101; A61M 25/0074
20130101; A61B 17/221 20130101; A61B 2017/22038 20130101; A61B
2017/2217 20130101; A61B 17/3207 20130101; A61B 2017/1107 20130101;
A61M 25/10 20130101; A61B 17/0644 20130101; A61B 2017/22077
20130101; A61B 90/39 20160201; A61M 2025/1079 20130101; A61B
2017/1135 20130101; A61M 25/0108 20130101; A61B 2017/00252
20130101; A61F 2/064 20130101; A61B 2017/2212 20130101; A61M
2025/0081 20130101; A61B 17/11 20130101; A61B 17/122 20130101; A61B
17/3478 20130101 |
Class at
Publication: |
606/108 |
International
Class: |
A61F 011/00 |
Claims
The invention claimed is
1. A guided punch, comprising: a sharp, extendible guide wire; and
a hollow punch mechanism adapted to ride on the guide wire, wherein
said guide wire is adapted to extend from said punch, and wherein
said punch comprises a hollow tube adapted to fit between said
punch mechanism and said guide wire.
2. A rotating punch, comprising: a sharp, central guide wire; a
rotating outer tube having a vascular cutting edge defined by a lip
of said tube; and a hollow tube adapted to be brought over said
guide wire and within said rotating outer tube.
3. An anastomotic connector, comprising: a cylinder-like body; and
at least one set of spikes, coupled to said body by twisting
joints, wherein said spikes are adapted not to penetrate tissue
which the spikes contact.
4. An anastomotic connector, comprising: a cylinder-like body; and
at least one set of spikes, coupled to said body by twisting
joints, wherein said set of spikes are bent at two different
locations along the spikes.
5. A method of performing an anastomosis, comprising: engaging at
least one of the vessels of a two vessel anastomosis, using a
plurality of retractable spikes; and retracting said plurality of
retractable spikes, to cause at least a partial eversion of said
vessel.
6. A method according to claim 5, comprising, completing said
anastomosis.
7. An anastomosis delivery system for delivering a connector having
at least one backwards spike having a bent tip, comprising: a
hollow guide sheath; a cylindrical capsule having one open end and
one closed end; and an anastomosis connector held in said
capsule.
8. A system according to claim 7, comprising a stopper arranged
between a plurality of said backwards spikes and urging said spikes
towards said capsule.
9. An anastomotic connector, comprising: a cylinder-like body; and
at least one set of spikes, coupled to said body by twisting
joints, wherein each spike comprises two arms that meet at a tip of
the spike and are each attached to a different part of said
connector.
10. A vascular attachment device for sealing an opening between two
blood conduit lips, comprising: a ring element; a plurality of
fingers mounted on said ring element and adapted to seal at least a
portion of an opening between two blood conduit lips by compressing
said at least two lips between a finger and at least one of said
finger and said ring; and at least one puller spike adapted for
pulling, inside the body, at least one of said lips to a space
defined between said finger and said ring.
11. A device according to claim 10, wherein said fingers are
restrained back from a resting position in which they engage said
lip in said space.
12. A device according to claim 10, wherein each puller has a sharp
tip adapted for insertion through a graft wall.
13. A device according to claim 10, wherein said ring has the shape
of an ellipse.
14. A device according to claim 10, wherein said fingers do not
penetrate any of said lips.
15. A vascular attachment device for sealing an opening between two
blood conduit lips, comprising a plurality of bendable clips, said
clips being adapted for gripping two lips between them and for
sealing said opening by forcing said lips towards each other,
wherein said clip elements are blunt and do not penetrate said
blood conduit walls.
16. A device according to claim 15, wherein said clips are arranged
on a ring.
17. A connector delivery system for delivering a ring connector
having a plurality of fingers, said fingers defining an open
configuration and a closed configuration mounted thereon,
comprising: a retractor; a tube integral with a plurality of puller
spikes and coupled to said retractor for retraction thereby; and an
outer tube adapted to close a plurality of said fingers, when said
puller spikes are retracted into said ring connector.
18. A system according to claim 17, wherein said fingers close
plastically.
19. A system according to claim 18, wherein said outer tube has an
inner lip with an inner diameter smaller than an outer diameter of
said connector, such that when said outer tube is moved relative to
said connector, said fingers are pushed inwards by the inner lip
towards said ring.
20. A system according to claim 17, wherein said fingers close to
said closed configuration by said fingers being released.
21. A system according to claim 20, wherein said outer tube defines
an inner lip, against which said fingers are held away from said
ring, such that when said outer tube is retracted, said fingers are
released from said lip and close.
22. A system according to claim 17, comprising a stationary tube
for maintaining said connector in place relative to said integral
tube.
23. A method of mounting a graft on a spiked connector, in which
the tips of the spikes define a periphery, comprising: placing the
graft, in said-periphery, between tips of said spikes and a
piercable element; impaling said piercable element on said spikes,
such that the graft is also impaled on said spikes; and removing
said piercable element from said spikes.
24. A method according to claim 23, comprising, pulling back
impaled parts of said graft to a side of the spikes opposite said
tips.
25. A method according to claim 23, wherein said impaling comprises
advancing said spike tips towards said graft.
26. A method according to claim 23, comprising bending said spike
tips into hooks after said impaling.
27. A method according to claim 23, comprising forming said spike
tips into hooks before said impaling.
28. A method of mounting a graft on a spiked connector, comprising:
placing the graft between tips of said spikes and an element having
a general outer perimeter; advancing said spikes relative to said
element such that said spikes penetrate said graft and penetrate
said perimeter; and removing said element.
29. A method according to claim 28, wherein said element is formed
of a hard material and includes a plurality of depressions to
receive said spikes.
30. A method according to claim 28, wherein said element is
piercable by said spikes.
31. A method according to claim 28, wherein said element is
non-expandable.
32. A method according to any of claims 28-31, wherein advancing
said spikes comprises advancing spikes that are adapted for
engaging a target vessel of the anastomosis.
33. A method of mounting a graft on a connector having a plurality
of spikes arranged around a central opening, said spikes having
radially outward pointing hooks, comprising: folding said spikes
such that said hooks point inward into said central opening and
define a periphery between them; inserting a graft into said
periphery; advancing said hooks relative to said graft, to
penetrate said graft; and repositioning said hooks to point
outward.
34. A method according to claim 33, wherein advancing said hooks
comprises moving said spikes.
35. A method according to claim 33, wherein advancing said hooks
relative to said graft comprises radially expanding said graft
towards said hooks.
36. A method according to claim 33, comprising, inserting a contra
mandrel in said graft, to limit an advance of said hooks.
37. A method according to any of claims 33-36, wherein
repositioning said hooks comprises unfolding said spikes.
38. A method of mounting a graft on a connector having a plurality
of spikes arranged around a central opening, said spikes having
radially outward pointing hooks, comprising: inserting a graft into
a periphery defined by forward ends of said spikes, in a first
direction; folding back a tip of said graft to cover said hooks;
and pulling back said graft, in a direction opposite said first
direction, such that said hooks engage said folded part of said
graft.
39. A method according to claim 38, comprising advancing said
engaged part of said graft towards a base of said spikes, in said
opposite direction.
40. An anastomotic connector, comprising: a base ring; a plurality
of target spikes, adapted to engage a target vessel, which target
spikes pass through said ring; and a plurality of retractable
pulling spikes, having tips adapted to engage a graft placed in the
lumen of said ring, and being adapted to at least partially evert a
lip of said graft when said pulling spikes are retracted.
41. A connector according to claim 40, wherein said target spikes
are hooked.
42. A connector according to claim 40, wherein said target spikes
are inclined towards an axis of said connector.
43. A connector according to claim 40, wherein said puller spikes
are provided through said base ring.
44. A method of partially everting a graft on a connector,
comprising: inserting a graft into a ring shaped anastomosis
connector having a plurality of spikes; and pulling an end of said
graft radially out, so that said end abuts said spikes adjacent the
spikes and extends radially out of said spikes between said
spikes.
45. A method according to claim 44, wherein said pulling comprises
pulling using retractable spikes.
46. A graft everting method, comprising: mounting at least an end
of said graft on an expandable tube; expanding said tube to engage
and expand said graft; and rolling back at least a portion of said
end over itself.
47. A method according to claim 46, comprising, providing a tube
over said graft, so said rolling back is on to said tube.
48. A tool for compressing a tip of a graft, comprising: an outer
mandrel mounted over the graft and reaching to about an opening in
the graft; an inner mandrel mounted inside the graft and reaching
to about said opening; and a base, wherein said base and said two
mandrel define a space for said graft to extend into when the
mandrels are brought together.
49. A tool according to claim 48, wherein said inner mandrel is
mounted on said base.
50. A tool according to claim 48, wherein said inner mandrel is
adapted to engage at least a portion of said graft.
51. A tool according to claim 48, wherein said outer mandrel is
adapted to engage at least a portion of said graft.
52. A tool for forming an oblique eversion for a graft, comprising:
a tube; and at least one axial extension of said tube, such that a
spiked connector disposed in said tube can project at least one of
its spikes near a base of said projection.
53. A tool according to claim 52, wherein said at least one
projection comprises at least two projections defining a slot
between them, with said spike extending through said slot.
54. A tool for forming an oblique eversion for a graft, comprising:
a tube adapted for having a graft and a connector mounted therein;
and an over-tube which radially restrains at least one spike of
said connector, wherein said connector can be moved relative to
said over-tube.
55. A tool according to claim 54, wherein said over tube is slotted
and wherein said motion is rotation.
56. A tool according to claim 54, wherein said motion comprises
axial motion of said connector relative to said over-tube.
57. A tool according to claim 56, wherein said tube is a same
element as said over tube.
58. A vascular attachment device for sealing an opening between two
blood conduit lips, comprising: at least one clip element adapted
for sealing at least a portion of an opening between two blood
conduit lips; and at least one puller adapted for pulling, inside
the body, at least one of said lips into said clip element, wherein
said puller is adapted to not penetrate said lip.
59. A vascular attachment device for sealing an opening between two
blood conduit lips, comprising: at least one clip element adapted
for sealing at least a portion of an opening between two blood
conduit lips; and at least one puller adapted for pulling, inside
the body, at least one of said lips into said clip element, wherein
said puller is adapted to be distorted by said clip.
60. A vascular attachment device for sealing an opening between two
blood conduit lips, comprising: at least one clip element adapted
for sealing at least a portion of an opening between two blood
conduit lips; and at least one puller adapted for pulling, inside
the body, at least one of said lips into said clip element, wherein
said clip comprises a slot, for engaging said lips.
61. A method of simulating eversion of a graft, comprising:
compressing an end of said graft into a form to provide a
thickening of said end; and transfixing said thickening with at
least one spike of an anastomosis connector.
62. A method according to claim 61, wherein said graft comprises a
mammary artery.
63. A method according to claim 61, wherein said transfixing
comprises transfixing along an axis of said graft.
64. A method according to claim 61, wherein said form comprises an
inner mandrel.
65. A method according to claim 61, wherein said form defines, on
said graft, a flat end surface for said thickening.
66. A method according to claim 61, wherein said form defines, on
said graft, an oblique end surface for said thickening.
67. A method according to claim 61, wherein said form defines, on
said graft, a nonplanar end surface for said thickening.
68. A method of transfixing a connector on a graft, comprising:
widening a radius of an end of the graft; advancing at least one
spike of said connector, parallel to said graft, such that it
transfixes said widened area; and bending at least an end of said
spike to form a hook.
69. An anastomosis connector, comprising: a plurality of ring
segments, together defining a radially expandable ring-like shape
having a lumen; at least one pivot bar coupled to at least one of
said ring segments; and at least one spike mounted on said pivot
bar and rotatable around said pivot bar, wherein radial deformation
of said ring-like shape does not substantially directly affect said
spike rotational position.
70. A connector according to claim 69, wherein said at least one
spike is pointed towards said ring-like shape.
71. A connector according to claim 69, wherein said at least one
spike is pointed away from said ring-like shape.
72. A connector according to claim 69, wherein said at least one
spike comprises at least two spikes, each mounted on a separate
pivot bar, wherein said spikes point in opposite directions along
an axis of said connector.
73. A connector according to claim 69, wherein said connector is
designed such that said at least one spike remains outside of a
side vessel in an end-to-side anastomosis.
74. A connector according to claim 69, wherein said connector is
designed such that said at least one spike enters a side vessel in
an end-to-side anastomosis.
75. A connector according to claim 69, wherein said pivot bar is
comprised in a spike element.
76. A connector according to claim 75, wherein said spike element
is attached to only a single ring element.
77. A connector according to claim 69, wherein said at least one
spike has a tip adapted to penetrate a blood vessel.
78. A connector according to claim 69, wherein said at least one
spike has a tip adapted to lay against a blood vessel without
penetrating it.
79. A connector according to claim 69, wherein said connector is
heat-treated to have said at least one spike perpendicular to said
ring.
80. A connector according to claim 69, wherein said connector is
heat-treated to have said at least one spike parallel to said
ring.
81. A connector according to claim 69, wherein said connector is
heat-treated to have said at least one spike bend.
82. A connector according to claim 69, wherein said connector is
heat-treated such that said at least one spike does not bend.
83. A connector according to claim 69, wherein said pivot bar is
within an axial extent of said ring-like shape.
84. A connector according to claim 83, wherein said pivot bar is
substantially centered relative to said ring like shape.
85. A connector according to claim 69, wherein said pivot bar is
outside an axial extent of said ring-like shape.
86. A connector according to claim 69, wherein said pivot bar is
straight.
87. A connector according to claim 69, wherein said pivot bar is
piece-wise straight.
88. A connector according to claim 69, wherein said at least one
spike is cut out of an opposing spike of said connector.
89. A connector according to claim 69, wherein at least one of said
ring segments comprises a plurality of axially spaced elements.
90. A connector according to claim 89, wherein said plurality of
elements comprises at least three elements.
91. A connector according to claim 89, wherein said plurality of
elements comprises at least four elements.
92. A connector according to claim 89, wherein said plurality of
elements comprises at least five elements.
93. A connector according to claim 89, wherein at least two of said
plurality of elements have mirrored geometries.
94. A connector according to claim 89, wherein at least one of said
plurality of elements has a single curve geometry.
95. A connector according to claim 89, wherein at least one of said
plurality of elements has a dual curve geometry.
96. A connector according to claim 89, wherein at least one of said
plurality of elements has at least three curves defined
thereby.
97. A connector according to claim 89, wherein at least one of said
plurality of elements has a varying width.
98. A connector according to claim 89, wherein all of said
plurality of elements have a constant width.
99. An anastomosis connector comprising: a ring shaped base having
an axis; at least one plurality of spikes on one side of said ring;
and at least one trans-axial thickening in at least one of said
spikes, distanced from said ring.
100. A connector according to claim 99, comprising a second
plurality of spikes pointing in an opposite direction from said
first set of spikes.
101. A rotating punch, comprising: a sharp, central guide wire; and
a rotating outer tube having a vascular cutting edge defined by a
lip of said tube.
102. A punch according to claim 101, wherein said outer tube
advances as it is rotated.
103. A punch according to claim 101, wherein said cutting edge is
smooth.
104. A punch according to claim 101, wherein said cutting edge is
serrated.
105. A punch according to claim 101, wherein said guide wire is
smooth.
106. A punch according to claim 101, wherein said guide wire is
adapted to engage vascular tissue it is inserted into.
107. A punch according to any of claims 101-106, wherein said outer
tube is bent at a right angle, such that positioning perpendicular
to a vessel wall is assisted.
108. A punch according to any of claims 101-106, comprising a
balloon distal from said cutting edge, said balloon, when inflated,
having an outer diameter slightly greater than a diameter of said
outer tube and about the inner diameter of a sheath associated with
said punch.
109. An advancing rotating punch, comprising: a sharp, central
guide wire; and a rotating outer tube adapted to cut a target
vessel which advances relative to said wire when it rotates.
110. A hole puncher, adapted for punching a hole in a blood vessel,
comprising: an outer tube having distal portion, which distal
portion has a lip; and a punch element having a sharp tip and
defining a depression distal from the tip, wherein said depression
is of a size adapted to receive a blood vessel, wherein said distal
portion of said outer tube has an outer diameter which is
substantially the same as an outer diameter of said punch element
and wherein said punch element fits snugly in said distal portion
such that said lip can sever blood vessel tissue contained in said
depression from tissue outside said depression.
111. A hole puncher according to claim 110, wherein said depression
is distanced from said tip so that said distance is at least the
thickness of the blood vessel.
112. A puncher according to claim 110, wherein said puncher is
flexible enough to be provided through a blood vessel in which a
hole is to be punched.
113. A puncher according to claim 110, comprising a handle.
114. A puncher according to claim 113, comprising means for
advancing said outer tube relative to said handle and relative to
said punch element.
115. A puncher according to claim 113, comprising means for
retracting said punch element relative to said handle and relative
to said outer tube.
116. A puncher according to any of claims 110-115, comprising means
for advancing a graft into said hole formed by said punch.
117. A puncher according to any of claims 110-115, wherein said
distal end is radially expandable from a first, small diameter to a
second, working diameter.
118. A method of punching a hole in a blood vessel, comprising:
providing a hole puncher to a location in a vascular system, which
location has blood flowing therethrough; transfixing a wall of said
vascular system at said location; removing a portion of said wall
using said hole puncher, while said hole-puncher remains
transfixing said wall; and transporting a tool across said wall
through a lumen of said hole puncher.
119. A method according to claim 118, wherein said removing
comprises partially retracting a portion of said hole puncher.
120. A method according to claim 118, wherein said removing
comprises partially advancing a portion of said hole puncher.
121. A method according to any of claims 118-120, wherein said
providing is from inside of said vascular system.
122. A method according to any of claims 118-120, wherein said
providing is from outside of said vascular system.
Description
[0001] This application is a division of U.S. patent application
Ser. No. 09/187,364, filed Nov. 6, 1998, which is hereby
incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to medical apparatus and methods, and
more particularly to apparatus and methods for installing a tubular
graft in a patient for such purposes as bypassing an occlusion in
the patient's tubular body conduit structure.
[0003] Goldsteen et al. U.S. Pat. No. 5,976,178, which is hereby
incorporated by reference herein in its entirety, shows, among
other things, apparatus and methods for installing a graft conduit
in a patient, with most or all of the work being done
intraluminally through the patient's existing body conduit
structure. Testing and further development work have suggested that
it would be advantageous to improve and/or augment some aspects of
apparatus and/or methods of the kind shown in the above-mentioned
Goldsteen et al. reference.
[0004] In view of the foregoing, it is an object of this invention
to improve and simplify various aspects of apparatus and methods of
the general type shown in the above-mentioned Goldsteen et al.
reference.
[0005] It is another object of this invention to provide additional
and/or alternative apparatus and/or methods for certain aspects of
technology of the general type shown in the Goldsteen et al.
reference.
SUMMARY OF THE INVENTION
[0006] These and other objects of the invention are accomplished in
accordance with the principles of the invention by providing
improved apparatus and methods for installing a guide structure in
a patient between two locations along the patient's circulatory
system that are to be connected by a bypass graft. The guide
structure extends between those two locations outside the
circulatory system (albeit within the patient) and is used to guide
the bypass graft into place between those two locations. The guide
structure is preferably installed in the patient intraluminally
(i.e., via lumens of the patient's circulatory system), although
there is a portion of the guide structure which ultimately extends
outside the circulatory system as mentioned above. A portion of the
guide structure may be re-routable in the circulatory system to
improve the alignment of the guide structure for purposes of
optimal guidance of the bypass graft into place. For example, the
guide structure may be re-routed so that, whereas both ends of the
guide structure initially extend out of the patient, only one end
of the re-routed guide structure extends out of the patient, while
the other end of the guide structure dead-ends in the patient.
Again, the new routing of the guide structure may improve its
ability to guide the bypass graft into a desired alignment in the
patient.
[0007] Improved apparatus and methods for delivering a bypass graft
conduit into the patient along the guide structure are also
provided. For example, the graft delivery structure may include a
very gradually tapered distal nose portion to facilitate entry of
the apparatus into the patient's circulatory system at one end of
the graft installation site. Improved connectors for attaching one
or both ends of the graft conduit to the patient's circulatory
system may also be used.
[0008] Further features of the invention, its nature and various
advantages will be more apparent from the accompanying drawings and
the following detailed description of the preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a simplified sectional view showing an early stage
in use of illustrative apparatus and methods in accordance with
this invention.
[0010] FIG. 2 is a view similar to FIG. 1 showing a later stage in
use of illustrative apparatus and methods in accordance with the
invention.
[0011] FIG. 3 is a simplified enlargement of a portion of FIG.
2.
[0012] FIG. 4 is a view similar to FIG. 2 showing a still later
stage in use of illustrative apparatus and methods in accordance
with the invention.
[0013] FIG. 5 is a simplified enlargement of a portion of FIG.
4.
[0014] FIG. 5a is another view similar to FIG. 5 showing an
alternative embodiment of the FIG. 5 apparatus.
[0015] FIG. 6 is a simplified cross sectional view of an
illustrative embodiment of a portion of the FIG. 5 apparatus in
accordance with the invention.
[0016] FIG. 7 is another view similar to FIG. 4 showing an even
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0017] FIG. 8 is a simplified enlargement of a portion of FIG. 7,
but with additional parts shown in section.
[0018] FIG. 9 is another view similar to FIG. 8 showing a later
stage in use of illustrative apparatus and methods in accordance
with the invention.
[0019] FIG. 9a is another view similar to FIG. 9 showing an
alternative embodiment in accordance with the invention.
[0020] FIG. 10 is another view similar to FIG. 9 showing a still
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0021] FIG. 11 is another view similar to FIG. 10 showing an even
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0022] FIG. 12 is another view similar to FIG. 11 showing a still
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0023] FIG. 13 is another view similar to FIG. 12 showing an even
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0024] FIG. 14 is another view similar to FIG. 7 showing a still
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0025] FIGS. 15a-e are simplified elevational views of components
of an illustrative embodiment of a portion of the apparatus shown
in FIG. 14.
[0026] FIG. 15f is a simplified elevational view taken along the
line 15f-15f in FIG. 15a.
[0027] FIG. 15g is a simplified sectional view taken along either
of the lines 15g-15g in FIG. 15c.
[0028] FIG. 15h is a simplified sectional view taken along either
of the lines 15h-15h in FIG. 15c.
[0029] FIG. 15i is a simplified sectional view taken along either
of the lines 15i-15i in FIG. 15e.
[0030] FIG. 15j is a simplified view, partly in section, of
additional components of an illustrative embodiment of a portion of
the apparatus shown in FIG. 14.
[0031] FIG. 15k is another view similar to FIG. 15f showing the
possible inclusion of additional components in accordance with the
invention.
[0032] FIG. 16 is a simplified view similar to a portion of FIG. 14
showing a later stage in use of illustrative apparatus and methods
in accordance with the invention.
[0033] FIG. 17 is a more detailed view similar to a portion of FIG.
16.
[0034] FIG. 18 is a simplified elevational view, partly in section,
of an illustrative embodiment of a portion of the apparatus shown,
for example, in FIG. 17 in accordance with the invention.
[0035] FIG. 19a is a simplified elevational view of a component of
another illustrative embodiment of a portion of the apparatus
shown, for example, in FIG. 17 in accordance with the
invention.
[0036] FIG. 19b is a simplified elevational view, partly in
section, showing an intermediate stage in processing the component
of FIG. 19a in accordance with the invention.
[0037] FIG. 19c is a simplified elevational view, partly in
section, showing a final condition of the component of FIG. 19a in
accordance with the invention.
[0038] FIG. 20a is a simplified elevational view illustrating
another possible feature of a portion of the apparatus shown, for
example, in FIG. 17 in accordance with the invention.
[0039] FIG. 20b is another view similar to FIG. 17 showing use of
the FIG. 20a feature in accordance with the invention.
[0040] FIG. 21a is another view similar to FIG. 20a illustrating an
alternative possible feature of a portion of the apparatus shown,
for example, in FIG. 17 in accordance with the invention.
[0041] FIG. 21b is another view similar to FIG. 21a showing another
operating condition of the FIG. 21a apparatus.
[0042] FIG. 21c is another view similar to FIG. 17 showing use of
the FIG. 21a-b feature in accordance with the invention.
[0043] FIG. 22 is another view similar to FIG. 17 showing a later
stage in use of illustrative apparatus and methods in accordance
with the invention.
[0044] FIG. 23 is another view similar to FIG. 22 showing a still
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0045] FIG. 24 is another view similar to FIG. 14 showing an even
later stage in use of illustrative apparatus and methods in
accordance with the invention.
[0046] FIG. 25 is another view similar to FIG. 24 showing a
possible additional feature of illustrative apparatus and methods
in accordance with the invention.
[0047] FIG. 26 is a simplified elevational view, partly in section,
of an illustrative embodiment of a portion of the FIG. 25 apparatus
in accordance with the invention.
[0048] FIG. 27 is a view similar to a portion of FIG. 25 showing
another illustrative embodiment of apparatus and methods in
accordance with the invention.
[0049] FIG. 28 is a view similar to FIG. 27 showing a later stage
in use of the FIG. 27 apparatus.
[0050] FIG. 29 is a view similar to FIG. 28 showing a still later
stage in use of the FIG. 27 apparatus.
[0051] FIGS. 30a and 30b collectively comprise a simplified
sectional view of an illustrative embodiment of further apparatus
in accordance with the invention. FIGS. 30a and 30b are sometimes
referred to collectively as FIG. 30.
[0052] FIG. 31 is a view similar to FIG. 25, but for the
alternative shown in FIG. 29, showing use of the apparatus of FIG.
30.
[0053] FIG. 32 is a view similar to a portion of FIG. 31 showing a
later stage in use of the FIG. 30 apparatus.
[0054] FIG. 33 is a view similar to FIG. 32 showing a still later
stage in use of the FIG. 30 apparatus.
[0055] FIG. 34 is a view similar to another portion of FIG. 31
showing a stage in use of the FIG. 30 apparatus comparable to the
stage shown in FIG. 33.
[0056] FIG. 35 is a view similar to FIG. 34 showing an even later
stage in use of the FIG. 30 apparatus.
[0057] FIG. 36 is a view similar to FIG. 35 showing a still later
stage in use of the FIG. 30 apparatus.
[0058] FIG. 37 is a view similar to FIG. 36 showing an even later
stage in use of the FIG. 30 apparatus.
[0059] FIG. 38 is a view similar to FIG. 31 showing an illustrative
end result of use of the apparatus and methods of this
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] 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.
[0061] As shown in FIG. 1, an early stage in an illustrative
coronary artery bypass procedure in accordance with the invention
includes introducing a longitudinal guide member 100 (typically a
guide wire, and therefore sometimes referred to as such herein)
into the patient's circulatory system across the coronary artery
occlusion 22 to be bypassed. For example, guide wire 100 may be
introduced into the patient via a femoral (leg) artery (not shown).
From the femoral artery, guide wire 100 may be pushed
intraluminally into the patient's aorta 30, and from the aorta into
the coronary artery 20 that has occlusion 22. Advancement of guide
wire 100 may be stopped at any desired point after the distal
portion of the guide wire has passed through occlusion 22.
[0062] After guide wire 100 is across occlusion 22 as shown in FIG.
1, a catheter or catheter-like structure 200 is introduced into the
patient along guide wire 100 as shown in FIG. 2. A more detailed
view of a distal portion of catheter 200 is shown in FIG. 3,
wherein it can be seen that the catheter has an axially extending
lumen 210 for containing guide wire 100 as the catheter is advanced
along the guide wire. Guide wire 100 facilitates passage of the
distal portion of catheter 200 through occlusion 22 as shown in
FIG. 2.
[0063] After the distal portion of catheter 200 has passed through
occlusion 22 as shown in FIG. 2, guide wire 100 is pulled
proximally out of the catheter and out of the patient.
[0064] A medial portion 220 of catheter 200 is preferably
constructed to form a laterally extending arch as shown in FIGS. 4
and 5 when guide wire 100 is withdrawn from the catheter. For
example, catheter 200 may be made so that it resiliently tends to
form an arch of a predetermined lateral extent when it is freed
from the straightening effect of guide wire 100. The arch height H
may be specifically designed to complement various artery sizes
(e.g., 3.0 mm, 3.5 mm, 4.0 mm, etc., diameter vessels). For
example, the arch height may be selected to be approximately the
same as or slightly greater than the inside diameter of the artery
20 into which the catheter will be inserted. In this way the bases
of the arch (in contact with one side of the interior of the artery
wall at axially spaced locations 20a and 20b) will push the apex of
the arch against the diametrically opposite side of the artery wall
(at location 20c, which is axially medial locations 20a and
20b).
[0065] The lumen 210 in catheter 200 has a side branch 210a which
exits from the side wall of the catheter at or near the apex of the
above-described arch in the catheter. Catheter portion 220, which
forms the above-described arch, is preferably loaded with
conventional radio-opaque filler (e.g., as indicated by the small
plus signs in FIG. 17) to help the physician using the apparatus to
radiologically locate and properly orient catheter portion 220 in
the patient's artery. Portions of catheter 200 which are distal and
proximal of portion 220 may be less radio-opaque to help highlight
portion 220. The objective is to position lumen branch 210a at the
approximate location along artery 20 at which it is desired to
connect one end of a bypass graft to the artery. Radiologic
observation may be further aided by providing a radiologically
viewable (e.g., radio-opaque) marker band around the exit from
lumen branch 210a (e.g., as shown at 224 in FIG. 17). (As a general
matter, the term "radiologic" is frequently used herein as a
generic term for any kind of radiologically viewable (e.g.,
radio-opaque) material or structure.)
[0066] Additional details of preferred constructional features of
catheter 200 are shown in the typical cross sectional view of FIG.
6. As shown in FIG. 6 the catheter tube preferably has an inner
liner 230 of polytetrafluoroethylene to minimize internal friction.
A reinforcing layer such as a braid of wires 250 may be included to
enable the catheter to transmit torque and to provide kink
resistance. Polymer layer 240 (e.g., Pebax or nylon) provides
support and curve retention. Internal lumen 210 preferably extends
along the entire length of the catheter and is used to allow the
catheter to track over guide wire 100 as described above, and to
subsequently guide a longitudinal piercing structure to the point
on the wall of artery 20 where it is desired to connect one end of
a bypass graft. (The piercing structure and its use will be
described in more detail shortly.) The distal tip portion of
catheter 200 may be made especially soft and/or the external
surface of the catheter may be coated with polytetrafluoroethylene
to enhance the ability of the catheter to pass through an occlusion
like occlusion 22. A soft tip also helps make catheter 200
atraumatic. The distal tip portion of the catheter may be tapered
in the distal direction for similar reasons. Overall, the
transverse dimensions of catheter 200 are preferably made small
(e.g., less than 3 French or 1.0 mm) to facilitate introduction of
the catheter into the patient, especially a relatively small
coronary artery and the even smaller passageway through the
occlusion 22 in that artery. Although polytetrafluoroethylene has
been mentioned for low friction layers or coatings, other materials
such as silicone and hydrophilic substances can be used instead of
polytetrafluoroethylene if desired. Arched section 220 is made
stiff enough to provide backup support for piercing the coronary
artery wall as described below, as well as stability of the
catheter in the coronary artery. Proximal sections of catheter 200
are constructed to provide appropriate pushability and trackability
of the catheter along guide wire 100. For example, catheter 200 may
have differing flexibility at different locations along its
length.
[0067] As an alternative to having a medial portion 220 of catheter
200 arch as shown in FIGS. 4 and 5 when guide wire 100 is withdrawn
from the catheter, a distal portion 220' of the catheter may be
configured to deflect or curve to the side when guide wire 100 is
withdrawn as shown in FIG. 5a. Catheter 200 in FIG. 5a is
positioned in coronary artery 20 so that after portion 220' curves
to the side, the distal end of lumen 210 points to a location on
the inside of the side wall of the artery similar to the location
of the apex of the arch 220 in FIG. 5 (i.e., the location on the
coronary artery side wall at which it is desired for a piercing
structure exiting from the distal end of lumen 210 to pierce the
side wall of the coronary artery as referred to above and as
described in more detail below). Thus in the embodiment shown in
FIG. 5a, lumen 210 does not need a separate, additional side exit
210a for the piercing structure because the distal end of lumen 210
can be used as the exit for the piercing structure. In other
respects, embodiments of the type shown in FIG. 5a can be
constructed and operated similarly to embodiments of the type shown
in FIG. 5 and described above. The deflection of portion 220' is
preferably such that after deflection one side of catheter 200
bears on the inside of one side of the coronary artery side wall at
location 20d in order to maintain the distal end of the catheter
close to or in contact with the other side of the coronary artery
side wall at axially spaced location 20e. Further depiction and
explanation of the invention will be made with reference to
embodiments of the FIG. 5 type, but it will be understood that
embodiments of the FIG. 5a type can be used instead if desired.
[0068] While it is not necessary to perform the above-described
coronary artery access steps of the invention first, it may be
preferable to do so to make sure that catheter 200 can be passed
through occlusion 22 before committing to the other steps that will
now be described.
[0069] A further step in accordance with the invention relates to
accessing the aortic end of the desired bypass around occlusion 22.
(See also Berg et al. U.S. patent application Ser. No. 09/014,759,
filed Jan. 28, 1998 and hereby incorporated by reference herein in
its entirety, for additional and/or alternative apparatus and/or
methods usable in the aortic access that will now be described.)
Another catheter or catheter-like structure 300 is introduced
intraluminally into the aorta as shown in FIG. 7. Like guide wire
100 and catheter 200, catheter 300 is preferably introduced into
the patient at a location remote from the coronary area. For
example, catheter 300 may be introduced into the patient via a
femoral artery. Also like guide wire 100 and catheter 200, the
distal portions of catheter 300 are preferably remotely controlled
from proximal portions of the apparatus which remain outside the
patient at all times.
[0070] A preferred construction of catheter 300 is shown in more
detail in FIG. 8. (See also Berg et al. U.S. Pat. No. 6,013,190,
hereby incorporated by reference herein in its entirety, for
possible additional and/or alternative features for catheter 300.)
There it will be seen that catheter 300 preferably includes pilot
wire 310 disposed substantially concentrically inside hollow
tubular needle catheter 320. Needle catheter 320 is disposed
substantially concentrically inside hollow tubular cutter catheter
330, which in turn is disposed substantially concentrically inside
hollow tubular aortic access catheter 340.
[0071] Catheter 300 is pushed into the patient until its distal
portion is adjacent the inside surface of the wall of the aorta
where it is desired to connect the aortic end of the bypass graft
around occlusion 22 (see FIGS. 7 and 8).
[0072] Needle catheter 320 is then pushed distally so that its
sharpened distal end portion passes through the wall of aorta 30 as
shown in FIG. 9. Note that, as FIG. 9 shows, needle catheter 320
preferably does not reach the pericardial membrane 40. The distal
portion of needle catheter 320 may be barbed as shown at 322 in
FIG. 9a to help prevent the needle catheter from being
inadvertently pulled back through the wall of aorta 30 and for
other purposes that will be mentioned below.
[0073] The next step is to push the distal portion of pilot wire
310 out of the distal end of needle catheter 320 and into the space
between aorta 30 and pericardial membrane 40 as shown in FIG. 10.
Wire 310 is preferably too flexible where not supported by needle
catheter 320 to pierce pericardial membrane 40. A quantity of wire
310 therefore deposits itself in the space between aorta 30 and
membrane 40 as shown in FIG. 10.
[0074] The next step is to push cutter catheter 330 in the distal
direction so that a sharpened distal end of catheter 330 makes an
annular cut through the wall of aorta 30 as shown in FIG. 11. If
provided as shown in FIG. 9a, barbs 322 on needle catheter 320 help
hold the toroidal "doughnut" 30a of aorta wall tissue that is cut
away by cutter catheter 330 on the distal portion of catheter 320.
Cutter catheter 330 may be rotated about its central longitudinal
axis to help it cut through the aorta wall tissue. After passing
through the aorta wall as shown in FIG. 11, the distal portion of
cutter catheter 330 tends to follow pilot wire 310 in the space
between aorta 30 and pericardial membrane 40. This helps prevent
cutter catheter 330 from inadvertently cutting through membrane 40.
A typical diameter for cutter catheter 330 is approximately 3 mm.
The cutter catheter shaft functions as a plug through the aperture
in the aorta wall that the cutter catheter has formed. This
prevents blood flow from the aorta into the pericardial space.
[0075] The next step is to push the distal portion of aortic access
catheter 340 through the aperture in the aorta wall that the cutter
catheter has formed as shown in FIG. 12. To do this, aortic access
catheter 340 uses the shaft of cutter catheter 330 as a guide.
Assuming that the diameter of the cutter catheter is approximately
3 mm, the diameter of aortic access catheter 340 may be
approximately 5 mm. The resulting expansion of the aortic opening
from 3 mm to 5 mm makes use of the elastic recoil of the aorta to
help seal the aortic opening around catheter 340, thereby ensuring
no blood leakage into the pericardial space while catheter 340 is
positioned through the aorta wall. The outer surface of catheter
340 may be coated with a hydrophilic material to facilitate
advancement through the aorta wall. If the aorta wall does not
provide sufficient elastic recoil, selectively inflatable annular
sealing balloons 340a and/or 340b can be added to catheter 340 to
provide sealing (see, for example, Berg et al. U.S. Pat. No.
6,013,190, which is hereby incorporated by reference herein in its
entirety). When inflated, balloons 340a and 340b bear resiliently
on the respective inner and outer surfaces of the aorta wall
annularly around the aperture through that wall. Balloons 340a
and/or 340b may also be desirable to help anchor the distal end of
catheter 340 through the aperture in the aorta wall. In particular,
balloon 340a (which is only inflated after catheter 340 has been
pushed through the aorta wall aperture) helps prevent catheter 340
from being inadvertently pulled back out of the aorta wall
aperture. Balloon 340b helps prevent catheter 340 from being pushed
too far through the aorta wall aperture.
[0076] The next step, shown in FIG. 13, is to pull all of
components 310, 320, and 330 proximally out of catheter 340. The
aorta wall tissue portion 30a cut away by cutter catheter 330 comes
out of the patient with components 310, 320, and 330. Barbs 322
(FIG. 9a) on needle catheter 320 help ensure that tissue portion
30a is thus removed from the patient.
[0077] A further step is shown in FIG. 14 and involves insertion of
snare structure 400 axially through the lumen of aortic access
catheter 300, starting from the proximal portion of the catheter,
until a distal portion of structure 400 extends from the distal end
of catheter 300 into the space between artery 20 and pericardial
membrane 40. Structure 400 is preferably steerable (at least in its
distal portion), and may include optical or video components to
help the physician guide the distal portion of structure 400 to the
vicinity of the distal portion 220 of catheter 200. The snare loop
412 on the distal end of wire 410 may not be extended from the
surrounding snare sleeve 420 as shown in FIG. 14 until after the
distal-most portion of sleeve 420 has reached the vicinity of
catheter portion 220.
[0078] Although structure 400 may be constructed in other ways,
particularly preferred constructions of some of the components of
that structure are shown in FIGS. 15a-j. In FIGS. 15a-e
horizontally aligned portions are superimposed on one another when
these various components are assembled in structure 400. Component
510 includes stranded pull wire 512 securely attached at its distal
end to metal bullet nose member 514. (In the assembled apparatus,
member 514 forms the distal end of structure 400 (not including the
possible further distal extension of snare loop 412 as shown in
FIG. 14).) Component 520 includes hypotube portion 522 secured at
its distal end to flat wire coil portion 524. Component 530 is a
multilumen polymer tube. Portion 532 is preferably a relatively
soft durometer polymer. Portions 534, 538, and 540 are preferably a
relatively hard durometer polymer. Portion 536 is preferably an
intermediate durometer polymer. Component 550 is a hollow tubular
braid of high tensile strength wires configured to fit
concentrically around the outside surface of portions 536 and 538
of component 530. For example, component 550 may be formed by
braiding several wires tightly around the outer surface of the
appropriate portions of component 530. Component 560 is a hollow
polymer tube adapted to fit concentrically around the outside of
component 550. For example, component 560 may be formed by
extruding suitable polymer material around the outside of component
550 on component 530 so that the material of component 560 bonds to
component 530 through interstices in component 550. Portion 562 is
preferably an intermediate durometer polymer (e.g., like portion
536). Portion 564 is preferably a relatively hard durometer polymer
(e.g., like portions 534, 538, and 540).
[0079] As can be seen in FIG. 15f, bullet nose 514 has a relatively
small axial bore 514a for receiving and attaching the distal end of
pull wire 512. Bullet nose 514 also has two relatively large bores
514b and 514c. In the assembled structure, bore 514a is axially
aligned with lumen 530a/530a' (or the similar diametrically
opposite lumen) in component 530 (see FIGS. 15g and 15h).
Similarly, in the assembled structure, bores 514b and 514c are
aligned with lumens 530b and 530c in component 530.
[0080] Component 530, initially without portion 540, may be formed
on several mandrels, each of which is subsequently pulled out the
proximal end of component 530 to leave a respective one of the
lumens in that component. Component 520 may then be inserted into
lumen 530a' from the proximal end of component 530. Component 510
may then be added from the distal end of component 530 so that pull
wire 512 passes through lumen 530a and component 520. Portion 540
may then be attached as shown in more detail in FIG. 15j.
[0081] An illustrative proximal handle and control portion of
structure 400 is shown in FIG. 15j. An enlarged handle member 570
is secured around portion 540 of component 530. Handle member 570
has an axial slot 572 in which slide block 580 is captive in the
radial direction of member 570 but slidable in the axial direction
of member 570. A thumb screw 582 is threaded into block 580 to act
as a handle for sliding block 580 axially relative to member 570
when the thumb screw is sufficiently loosely threaded into block
580, and to act as a releasable lock for locking block 580 in any
desired axial position along slot 572 when thumb screw 582 is
threaded more tightly into block 580 and therefore against the
outer surface of handle member 570.
[0082] A side region of portion 540 is notched at 542 to allow the
proximal portion of pull wire 512 to come out of the side of
portion 540 for looping through block 580. The loop in pull wire
512 is fixed by a crimp 516 around the wire at the base of the
loop. Accordingly wire 512 can be pulled proximally by various
amounts relative to the remainder of structure 400 by sliding block
580 proximally relative to handle member 570. Pulling wire 512
proximally causes the relatively soft distal portion 532 of
component 530 to curve in the direction of the side of component
530 that wire 512 is closest to. Relaxing wire 512 allows portion
532 to straighten out again. The above-described curving is largely
confined to distal portion 532 because that portion is made of the
softest material and because component 520 substantially reduces
any tendency of other axial portions of the apparatus to curve in
response to tension in wire 512. All axial portions of structure
400 are, however, sufficiently flexible to pass along the patient's
tubular body structure through aortic access catheter 300.
[0083] Component 550 helps structure 400 transmit torque from its
proximal handle 570 to its distal end. The physician can use the
combination of such torque and the ability to curve the distal
portion 532 of structure 400 to maneuver the distal portion of that
structure from the distal end of catheter 300 to a location
adjacent catheter portion 220, all preferably inside pericardial
membrane 400. Radiologic markers may be provided on structure 400
to help the physician determine when the distal portion of that
structure is properly located. One (or more) of the lumens through
component 530 (and bullet nose 514) may be used to enable structure
400 to also function as an endoscope to aide in maneuvering the
distal portion of structure 400 adjacent to catheter portion 220.
As shown in FIG. 15k, for example, optical fibers 502 extending
along a lumen of component 530 may be used to convey light from
outside the patient to illuminate the interior of the patient just
beyond bullet nose 514. Other parallel optical fibers 504 may be
used to convey the resulting illuminated scene back to an eyepiece
or other optical or video viewing apparatus outside the
patient.
[0084] A luer 590 may be attached to the proximal end of portion
540 as shown in FIG. 15j, if desired, so that the luer conduit 592
communicates with one (or more) of the lumens through components
530 (and bullet nose 514). This may provide the passage via which
the above-mentioned optical fibers 502/504 exit from the remainder
of the apparatus. It may also form a passageway for introducing
fluids into or draining fluids from the patient adjacent bullet
nose 514.
[0085] Another of the lumens through component 530 (and bullet nose
514) is opened outside the patient via the notch 544 (FIG. 15j) in
a proximal part of portion 540. Notch 544 provides the entrance
point for snare loop 412 and wire 410. The portion of structure 400
around this lumen therefore forms what is referred to as the snare
sleeve 420 in the earlier discussion of FIG. 14.
[0086] It will be understood that any number of passageways like
514b-c/530b-c can be provided through elements 514 and 530.
[0087] Components 410 and 412 can take any of many forms, some
alternatives being specifically illustrated and described later in
this specification. For present purposes, however, it will be
sufficient to assume that component 412 is a loop of wire which is
secured to the distal-end-of wire 410 and which is-resiliently
biased to spring open when extended distally from the distal end of
a lumen in sleeve 420 as shown in FIG. 14. Also as shown in FIG.
14, the distal portion of sleeve 420 is preferably positioned in
the patient so that when loop 412 is extended distally from sleeve
420, loop 412 will receive a pierce structure passed out of
coronary artery 20 via catheter portion 220 as will now be
described.
[0088] A further step is illustrated by FIG. 16 and involves
inserting an elongated piercing structure 600 (e.g., primarily a
metal wire or wire-like structure) into catheter 200 along the
lumen 210 formerly used for guide wire 100. Because catheter
portion 220 is now arched as shown in FIG. 16, the distal end of
piercing structure 600 tends to follow lumen branch 210a out of
catheter 200 and into contact with the interior surface of the side
wall of coronary artery 20. The distal tip of piercing structure
600 is sufficiently sharp and structure 600 is sufficiently stiff
that the distal tip of structure 600 can be pushed out through the
coronary artery wall tissue (see also FIG. 17). Continued distal
pushing of structure causes the portion outside coronary artery 20
to pass through snare loop 412. The distal portion of piercing
structure 600 is, however, preferably not strong enough, when
outside coronary artery 20 and therefore unsupported by catheter
lumen 210, to pierce or otherwise damage pericardial membrane 40.
The main component of structure 600 may be metal (e.g., nitinol)
wire. Radiologically visible marker bands 610 may be provided on
the distal portion of piercing structure 600 to help the physician
monitor the progress and position of that portion of structure 600.
Alternatively, structure 600 may be made of a radiologic (e.g.,
radio-opaque) material such as tungsten wire.
[0089] An illustrative construction of the distal portion of
structure 600 is shown in more detail in FIG. 18. There it will be
seen that this part of structure 600 has a sharpened distal tip
portion 620, which may be approximately 0.1 inches in length.
Behind the distal tip is a relatively slender elongated portion
630. For example, portion 630 may have a diameter of approximately
0.006 inches and a length of approximately 1.575 inches. A hollow
frusto-conical dilator 640 may be provided a short distance in from
the distal end of portion 630. Just proximal of dilator 640 portion
630 may be wound with a radiologically viewable wire 650. For
example, wire 650 may be gold or platinum wire. Dilator 640 helps
provide a gradual transition from the smaller diameter of portion
630 distal of wire 650 to the larger diameter produced by the
addition of coil 650. Proximal of portion 630, structure 600
transitions gradually to relatively large diameter portion 660. For
example, the diameter of portion 660 may be approximately 0.01
inches.
[0090] Distal portions 620 and 630 are stiff enough, when supported
by lumen 210, to pierce the wall of coronary artery 20. At a
greater distance from the support of lumen 210, however, portions
620 and 630 are preferably not stiff enough to pierce or otherwise
damage pericardial membrane 40. In addition, distal portions 620
and 630 are not stiff enough to straighten out arched catheter
portion 220 when portions 620 and 630 are inside catheter portion
220. The relatively slender distal portions 620 and 630 of
structure 600 engage and pierce the wall of coronary artery 20
before the larger proximal portion 660 enters the curved portion
220 of catheter 200. Proximal portion 660 is made somewhat larger
and therefore stiffer to help transmit the pushing force required
to enable distal portions 620 and 630 to pierce the coronary artery
wall.
[0091] Another illustrative way to provide marker bands 610 on
piercing structure 600 is shown in FIGS. 19a-c. In this embodiment
the distal portion 630 of structure 600 is provided with several
diametrically enlarged portions 632 axially spaced along portion
630. The distal portion of structure 600 is inserted into the lumen
of a heat shrinkable tube 670 which initially has an inner diameter
which is slightly greater than the outer diameter of enlarged
portions 632. A radiologically viewable adhesive 634 is then
injected into tube 670 so that the adhesive flows around the
outside of distal portion 630. Tube 670 is then heat shrunk to more
closely conform to the outer diameter of portion 630, and adhesive
634 is then cured. Tube 670 is then removed, and the extreme
proximal and distal regions of adhesive 634 are tapered down to the
diameter of portion 630. The resulting bands of adhesive 634
adjacent to or between portions 632 provide radiologically viewable
markers 610 on structure 600.
[0092] A highly desirable feature of structure 600 no matter how it
is constructed (e.g., as in FIG. 18, FIGS. 19a-c, or in any other
way) is that it has a substantially transitionless external profile
to ensure continual passage through the arterial wall. Any slight
edges may snag on the artery wall and prevent structure 600 from
exiting the coronary artery. Thus radio-opacity (e.g., 610, 634,
650) is preferably provided in structure 600 without adding abrupt
transitions. Such radio-opacity allows efficient snaring of the
distal end of structure 600 inside the pericardial sac.
Radio-opaque markers 610 can be plated, bands, or coils. Suitable
marker materials include gold, tungsten, and platinum. Radio-opaque
markers having predetermined spacing may also be provided along the
length of structure 600 to make it possible to use structure 600 to
measure the length of graft needed between aorta 30 and coronary
artery 20. This possible use of radiologic markers on structure 600
will become clearer as the description proceeds. The basic material
of structure 600 is preferably super-elastic nickel titanium
(nitinol), but other possible materials include stainless steel,
tantalum, and suitable polymers.
[0093] As has been mentioned, structure 600 may be made of a
radiologically viewable material such as tungsten to eliminate the
need for the above-described radiologic markers 610/650/634.
[0094] FIGS. 20a and 20b illustrate a feature that piercing
structure 600 may be provided with to help ensure that the piercing
structure does not inadvertently pierce pericardial membrane 40
after exiting from artery 20. A distal portion of piercing
structure 600 may be resiliently biased to deform into a serpentine
shape 680 when it is no longer constrained to remain substantially
straight by being inside catheter lumen 210. Thus, as the distal
portion of piercing structure 600 exits from coronary artery 20 as
shown in FIG. 20b, it takes on the above-described serpentine
shape. When thus shaped, it is practically impossible to push the
distal portion of piercing structure 600 through pericardial
membrane 40. The serpentine shape of the distal portion of piercing
structure 600 also helps ensure that at least some of that
structure stands off outside coronary artery 20, thereby
facilitating snaring of that portion of structure 600 by snare loop
412.
[0095] Another possible construction of the distal portion of
structure 600 is shown illustratively in FIG. 21a-c. In this
embodiment an axially medial portion of structure 600 close to the
sharpened distal tip is cut through axially as indicated at 690 in
FIG. 21a. In addition, the two lateral halves of the cut portion of
structure 600 may be resiliently biased to spring apart as shown in
FIG. 2b when unconstrained by lumen 210. While in lumen 210, the
two lateral halves of cut structure 600 remain together, and with
the support of lumen 210 the structure has sufficient column
stiffness to pierce the wall of artery 20. Shortly after emerging
from artery 20, however, the two lateral halves of structure 600
can separate as shown in FIG. 2c, and structure 600 loses its
ability to pierce any further tissue such as pericardial membrane
40. The loop 692 that forms in the distal-most portion of structure
600 outside artery 20 provides an alternative means by which snare
structure 400 can engage structure 600. In particular, a hook 412a
can be used to hook onto loop 692 as shown in FIG. 21c.
[0096] As an alternative or addition to snaring the distal portion
of piercing structure 600 with a snare loop 412 or hook 412a, other
technologies may be used to make or help make a connection between
structures 410 and 600. For example, the distal portion of
structure 600 may be or may include a ferromagnetic material, and
structure 410 may include a distal magnet for attracting and
holding that ferromagnetic material. As another example, the distal
portion of structure 410 may include a pliers-like gripper for
closing on and gripping the distal portion of structure 600. As an
alternative or addition to using fiber optics or the like in
structure 400 to allow what might be called direct visual
observation of the snaring of structure 600 by structure 410, both
of these structures may be made of radiologic materials such as
tungsten to permit radiologic observation of the snaring
maneuvers.
[0097] After a suitable connection or interengagement has been
established between structures 410 and 600, a further step includes
pulling structure 410 back proximally in order to pull structure
600 into structure 400. (In cases in which structure 600 is snared
by a loop 412, the immediately above-mentioned step may be preceded
by operating or manipulating structure 400 to close loop 412 on
structure 600, and preferably also to deflect structure 600 around
a portion of loop 412. For example, FIG. 22 shows shifting
structure 400 distally relative to loop 412 to cause the loop to
close and to deform structure 600 into what is effectively a hook
through the closed loop. This provides a very secure link between
structures 410 and 600.) As structure 410 is pulled back proximally
relative to structure 400, structure 600 is pulled into structure
400. To help reduce the pulling stress on elements 410 and 600,
additional length of structure 600 may be pushed into the patient
at approximately the same rate that structure 410 is being pulled
out of the patient. Eventually, structure 410 may be pulled
completely out of the patient, and structure 600 may extend
continuously through the patient from its initial entry point to
the initial entry point of structure 410. The condition of the
portions of the patient and apparatus shown in FIG. 22 may now be
as shown in FIG. 23.
[0098] A further step is to withdraw structure 400 from the
patient. Structure 200 may also be withdrawn from the patient or is
at least proximally retracted somewhat. The condition of the
relevant portion of the patient and the apparatus after these
operations may be as shown in FIG. 24. (FIG. 24 illustrates the
case in which structure 200 is proximally retracted rather than
being fully withdrawn from the patient at this stage.)
[0099] To help provide a graft which connects to coronary artery 20
with an acute angle between the graft and the upstream portion of
the coronary artery, it may be desirable to construct structure 600
so that a portion of that structure can be made to extend down into
the downstream portion of the coronary artery beyond the point at
which structure 600 passes through the side wall of the artery. An
example of this type of structure 600 is shown in FIGS. 25 and 26.
(FIG. 25 also illustrates a case in which structure 200 is
completely withdrawn from the patient after structure 600 has been
fully placed in the patient.)
[0100] For operation as shown in FIG. 25, structure 600 may be
constructed as shown in FIG. 26 with an axially medial portion 662
having significantly greater flexibility than the axially adjacent
portions of that structure. For example, structure 600 may have
reduced diameter in region 662 to increase its flexibility in that
area. Portion 662 may be provided with a radio-logic marker 664
(e.g., a wire of radio-opaque material wrapped around that portion
of structure 600) to facilitate proper placement and other
observation of portion 662 in the patient. Marker 664 preferably
does not interfere with the increased flexibility of portion
662.
[0101] Continuing with the illustrative embodiment shown in FIGS.
25 and 26, after structure 600 has been established through the
patient (e.g., as shown in FIG. 24), structure 600 is shifted
axially in the patient until portion 662 is inside coronary artery
20 adjacent the point at which structure 600 passes through the
side wall of the artery. This can be determined by radiologic
observation of marker 664. Then both end portions of structure 600
can be pushed into the patient to cause structure 600 to
essentially fold or prolapse at portion 662 and to push folded
portion 662 down into the downstream portion of artery 20 as shown
in FIG. 25. This causes the portion of structure 600 which is
outside the upstream portion of artery 20 to form an acute angle A
with the upstream artery portion. Such an acute angle A may be a
preferable angle of approach for the bypass graft which is to be
installed along structure 600 as described elsewhere in this
specification.
[0102] Another alternative (apparatus and method) for re-routing
structure 600 in the patient (e.g., to achieve an acute angle
approach of structure 600 to the outer surface of coronary artery
20) is shown in FIGS. 27-29. In this alternative the proximal end
of the portion of structure 600 that extends up and out of the
patient via coronary artery 20 is preferably provided with an
atraumatic end 602. In the illustrative embodiment shown in FIGS.
27-29 atraumatic end 602 is a ball which covers what might
otherwise be a relatively sharp end of structure 600. When it is
desired to reroute structure 600 in the patient, structure 600 is
pulled axially relative to the patient in the direction indicated
by arrow 604a. This pulls atraumatic end 602 into the patient and
ultimately into coronary artery 20 as shown first in FIG. 27 and
then still farther as shown in FIG. 28.
[0103] When atraumatic end 602 reaches the condition shown in FIG.
28 where it is adjacent to the aperture in the side wall of
coronary artery 20 through which structure 600 passes, the
resilience of structure 600 (which, as has been said, may be a
metal wire) causes what remains of structure 600 in the vicinity of
the coronary artery side wall aperture to straighten. This causes
the end 602 of structure 600 to move in the downstream direction
along coronary artery 20 as shown in FIG. 28. The next step is to
begin to push structure 600 back into the patient as shown by arrow
604b in FIG. 29. This causes end 602 to move in the downstream
direction along the coronary artery lumen as is also shown in FIG.
29, thereby ultimately giving structure 600 a new routing
immediately outside coronary artery 20 like the routing of the
corresponding portion of structure 600 in FIG. 25.
[0104] It will be apparent from consideration of FIGS. 27-29 that
at least the depicted portion of structure 600 is sufficiently
laterally flexible to enable a distal part of that structure to
extend inside the lumen in the upper portion of coronary artery 20,
while a proximal part of structure 600 extends axially along a path
606 that is outside the upper portion of the coronary artery and
that forms an acute angle C with a line 608 parallel to the upper
portion of the artery. In other words, path 606 extends back along
the outside of the upper portion of artery 20. At least the
depicted portion of structure 600 is also sufficiently resilient so
that when the part of structure 600 that remains in the lumen in
the upper portion of coronary artery 20 becomes too short to
continue to be constrained or guided by that artery portion, the
part of structure 600 that remains in the artery switches
resiliently into the lower portion of the artery as shown in FIG.
28. This switching happens automatically as a result of structure
600 resiliently tending to straighten when it is not otherwise
deflected or constrained by its contact with the interior surfaces
of artery 20. At least the depicted portion of structure 600 is
also sufficiently laterally stiff that the distal part can be
pushed down into the lower portion of artery 20 when the proximal
part is pushed in the distal direction as indicated by arrow 604b
in FIG. 29. In addition to providing an atraumatic end to structure
600, the fact that end 602 is radially enlarged relative to the
axially adjacent portion of structure 600 helps prevent end 602
from being inadvertently pulled proximally out of artery 20 when
the structure approaches the condition shown in FIG. 28 and before
structure 600 begins to be pushed into the artery again as shown in
FIG. 29.
[0105] The procedure illustrated in FIGS. 27-29 may be facilitated
by radiologic observation of radiologic markers provided at any
desired location or locations on structure 600. For example,
atraumatic end 602 may itself be made of a radiologic material such
as gold, platinum, silver, tungsten, or any other suitable
substance.
[0106] When the condition of the patient is as shown in FIG. 24,
25, or 29, depending on the apparatus and procedural options
selected, the patient is ready for installation of a tubular bypass
graft along structure 600 between the distal end of structure 300
and the point at which structure 600 passes through the side wall
of coronary artery 20.
[0107] An illustrative embodiment of a tubular graft 42 and
structure 800 for delivering and installing the graft along
structure 600 is shown in FIG. 30 (which comprises FIGS. 30a and
30b connected between the right in FIG. 30a and the left in FIG.
30b). It should be understood that the portion of structure 800
that is shown in FIG. 30b remains outside the patient at all times,
and that structure 800 may have any desired length between the
distal portion shown in FIG. 30a and the proximal portion shown in
FIG. 30b. Graft 42 is shown in FIG. 30 with a connector 50 at its
proximal end for use in connecting the graft to the side wall of
the patient's aorta 30. Connector 50 may be of a type shown in
Peterson et al. U.S. Pat. No. 6,152,937, which is hereby
incorporated by reference herein in its entirety. Graft 42 is also
shown in FIG. 30 with a connector 60 at its distal end for use in
connecting the graft to the patient's coronary artery 20. Connector
60 may be of a type shown in Galdonik et al. U.S. patent
application Ser. No. 09/187,361, filed Nov. 6, 1998, which is
hereby incorporated by reference herein in its entirety.
[0108] Graft 42 is assumed to be a length of the patient's
saphenous vein which has been harvested for use in the coronary
artery bypass procedure being described. It will be understood
however, that other natural body conduit can be used for graft 42,
or that graft 42 can be a synthetic graft or a combination of
natural and synthetic materials. It will also be understood that
the particular connectors 50 and 60 shown in FIG. 30 are only
illustrative and that other connectors can be used instead if
desired. For example, connectors of the type shown in Swanson et
al. U.S. Pat. No. 6,113,612, which is hereby incorporated by
reference herein in its entirety, can be used for distal (coronary
artery) connector 60. Connectors of the type shown in the
above-mentioned Peterson et al. reference can also be used for
distal connector 60.
[0109] Tube 810 is configured for disposition substantially
concentrically around structure 600 and for sliding axially along
that structure. Tube 810 may be made of stainless steel hypotube so
that it can bend laterally to follow whatever straight or curved
path structure 600 has in the patient. Tube 810 is axially strong
enough to transmit pushing or pulling force between proximal
actuator structure 812 and distal tip structure 820, both of which
are secured to tube 810 at respective opposite ends thereof. Distal
tip structure 820 has a substantially conical distal-most outer
surface portion 822 and a more proximal, substantially cylindrical
surface portion 824. The cone angle B of conical surface portion
822 is preferably relatively small (e.g., in the range from about
5.degree. to about 15.degree., more preferably in the range from
about 5.degree. to about 10.degree.). This helps structure 820 to
gradually enlarge the aperture through the epicardial membrane and
the side wall of coronary artery 20 and thereby enter the artery
without the artery collapsing as a result of too much force being
applied to the exterior. Angle B is sometimes referred to herein as
the "cone angle." Tip structure 820 includes an annular recess 826
in its proximal portion for receiving the distal-most portions of
structure 830/832 (described below), connector 60, and graft
conduit 42.
[0110] Tube 830 is disposed substantially concentrically around
tube 810 and is slidable axially relative to tube 810. Annular
balloon 832 is secured to a distal portion of tube 830. Actuator
structure 834 and luer connector 836 are secured to a proximal
portion of tube 830. The side wall of tube 830 preferably includes
a lumen (not shown) which extends from connection 836 to the
interior of balloon 832 so that the balloon can be inflated or
deflated by appropriately directed fluid flow through that lumen.
Balloon 832 is shown deflated in FIG. 30.
[0111] Tube 830 is again sufficiently laterally flexible to allow
structure 800 to follow whatever path structure 600 has in the
patient. Tube 830 is also axially strong enough to transmit pushing
or pulling force axially between balloon 832 and actuator structure
834, although the axial force tube 830 is required to transmit is
typically less than the axial force tube 810 must transmit.
Examples of suitable materials for tube 830 include polymers such
as nylon, Teflon, and polyethylene.
[0112] Connector 60 is disposed annularly around balloon 832. In
FIG. 30 connector 60 has its initial, relatively small,
circumferential size. Fingers 62 extend radially out from the main
portion of connector 60 in order to pass through the distal end
portion of graft conduit 42 and thereby secure the graft to the
connector. Other graft-to-connector securing means such a sutures
may be used instead of or in addition to fingers 62. Connector 60
can be plastically circumferentially enlarged by inflation of
balloon 832 as described below when tip structure 820 is shifted
distally relative to balloon 832 to fully expose elements 832 and
60 and the distal end portion of graft conduit 42. In the condition
shown in FIG. 30, however, tip structure 820 shields and protects
elements 832, 60, and 42 and provides a smooth profile for
facilitating entry of these elements into the patient's coronary
artery through an aperture in the side wall of that artery (see the
following discussion of use of apparatus 800). Additional details
regarding suitable constructions of connector 60 will be found in
the above-mentioned Galdonik et al. reference.
[0113] The components of structure 800 that have thus far been
described are particularly associated with positioning and control
of distal connector 60. The further components of structure 800
that will now be described are particularly associated with
positioning and control of proximal connector 50.
[0114] Tube 840 is disposed substantially concentrically around
tube 830. Tube 840 is slidable axially along tube 830-by proximal
actuator 842, but preferably includes a proximal structure 844
(e.g., a collet-type structure) for allowing tube 840 to be
releasably locked to tube 830 at various axial locations along tube
830. In this way tubes 830 and 840 can be shifted axially relative
to one another to accommodate any desired length of graft conduit
42. When structure 800 is thus adjusted for a particular length of
graft conduit, structure 844 can be operated to lock tubes 830 and
840 relative to one another for that length of graft.
[0115] Annular connector 50 is shown in FIG. 30 in its initially
relatively small circumferential size. Connector 50 is resiliently
biased to circumferentially enlarge to a larger final
circumferential size, but is prevented from doing so by the
surrounding distal cone portion 846 of tube 840. Most of connector
50 is disposed annularly around tube 840, but distal portions 52a
of the connector enter a proximal-facing annular recess in cone
portion 846 which helps to maintain the initial small
circumferential size of the connector.
[0116] Proximal of portions 52a connector 50 includes radially
outwardly extending graft retention fingers 52b that pass through
the proximal end portion of graft conduit 42 to secure the
connector to the graft conduit. Other graft-to-connector securing
means such as sutures can be used instead of or in addition to
fingers 52b.
[0117] Still more proximal of fingers 52b connector 50 includes
"inside" fingers 52c and "outside" fingers 52d. Inside fingers 52c
are resiliently biased to spring radially out, but are initially
held relatively parallel to the longitudinal axis of structure 800
by being confined inside a distal end portion of tube 850. Outside
fingers 52d are also resiliently biased to spring radially out, but
are initially held relatively parallel to the longitudinal axis of
structure 800 by being confined inside catheter 300 (which is
already in place in the patient as shown, for example, in FIG. 25).
Tube 850 is disposed substantially concentrically around tube 840
and is axially slidable relative thereto by proximal actuator 852.
Tube 860 is disposed substantially concentrically around tube 850
and is axially slidable relative thereto by proximal actuator 862.
The distal end of tube 860 is axially aligned with proximal
portions of fingers 52d. Each of tubes 840, 850 and 860 is
sufficiently laterally flexible so as not to interfere with the
ability of structure 800 to follow any path that structures 300 and
600 have in the patient. Each of tubes 840, 850, and 860 is also
axially strong enough to transmit necessary forces axially along
the tube between the associated proximal actuator 842, 852, or 862
and the operative distal end portion of the tube. As has been
mentioned, additional details of suitable constructions for
connector 50 can be found in the above-mentioned Peterson et al.
reference.
[0118] Structure 800, with a suitable length of graft 42 and
associated connectors 50 and 60 mounted thereon as shown in FIG.
30, is inserted axially into the patient along structure 600 and
inside catheter 300 as shown in FIG. 31. At the distal end of
catheter 300, the distal portion of structure 800 emerges from the
catheter and therefore from the patient's aorta 30 and continues to
follow structure 600 toward the side wall of the-patient's coronary
artery 20.
[0119] Continued distal pushing of structure 800 axially along
structure 600 causes the conical distal tip 820 of structure 800 to
begin to penetrate the side wall of the coronary artery as shown in
FIG. 32, thereby gradually enlarging the aperture in the coronary
artery side wall previously occupied solely by structure 600.
Structure 800 continues to be pushed distally until distal tip
structure 820 is entirely inside the coronary artery, as is
connector 60 and the distal portion of graft 42. Then tube 830 is
held stationary while tube 810 continues to be pushed distally.
This causes distal tip structure 820 to separate from connector 60
and the associated distal portions of graft 42 and structure
830/832 (see FIG. 33).
[0120] Balloon 832 is then inflated to circumferentially
plastically enlarge connector 60 as shown in FIG. 33. Connector 60
thereby presses the surrounding distal portion of graft 42 radially
out against the inner surface of the coronary artery wall, which
both holds the distal end of the graft inside the coronary artery
and provides a hemodynamic seal between the graft and the coronary
artery. If desired, connector 60 can be long enough to extend
upstream inside graft 42 and out the aperture in the coronary
artery side wall to help hold open the graft where it passes
through that aperture and to help the graft seal the aperture.
After connector 60 has been thus radially enlarged, balloon 832 can
be deflated again.
[0121] FIG. 34 illustrates the condition of the portion of
structure 800 in the vicinity of connector 50 when the distal
portion of the apparatus is as shown in FIG. 33. In particular,
outside fingers 52d of connector 50 are preferably just outside the
side wall of aorta 30.
[0122] The next step is to proximally retract catheter 300 while
holding tubes 840, 850, and 860 stationary. This releases outside
fingers 52d to spring radially out as shown in FIG. 35. Tube 840
can then be pulled proximally back somewhat to snug fingers 52d up
against the wall of aorta 30 as is also shown in FIG. 35.
[0123] The next step is to proximally retract tube 850. This allows
inside fingers 52 to spring radially out inside the side wall of
the aorta 30 as shown in FIG. 36.
[0124] The next step is to shift tube 840 distally, which releases
connector 50 from the circumferential restraint of the distal
portion 846 of that tube. This allows connector 50 to resiliently
fully enlarge to its final, relatively large circumference as shown
in FIG. 37.
[0125] All of structures 300, 600, and 800 can then be withdrawn
proximally from the patient. This leaves the final condition of the
patient as shown in FIG. 38, i.e., with connector 50 providing an
anastomotic connection between the side wall of aorta 30 and the
proximal end of graft conduit 42, and with connector 60 providing
an anastomotic connection between the distal end of graft conduit
42 and the inside of coronary artery 20 downstream from occlusion
22. The downstream portion of coronary artery 20 is thereby
supplied with aortic blood via bypass graft conduit 42. As much as
possible of the work of installing graft 42 has been performed in a
minimally invasive way, and in particular via lumens of the
patient's circulatory system.
[0126] A desirable feature of structure 800 is the fact that the
proximal and distal connector delivery components are independent
of one another in terms of deployment controls. The distal
connector delivery and deployment components are coaxially inside
the proximal connector delivery and deployment components. After
graft 42 has been attached to connectors 50 and 60, the space
between the respectively associated portions of structure 800 can
be adjusted to add or remove graft length between the connectors as
needed. Structure 844 can then be used to fix this distance once
the required space between the connectors is set.
[0127] Radiologic markers on structure 800 and/or on connectors 50
and 60 can be used to help the physician properly position these
components relative to circulatory system conduits 20 and 30 during
the operational steps described above.
[0128] It will be noted that the present invention is suitable for
adding a new length of graft conduit to a patient's circulatory
system between two points on that system that can be quite widely
spaced from one another (as in the case of the aorta, on the one
hand, and a coronary artery beyond an occlusion, on the other
hand). The graft is installed outside the patient's existing
circulatory system through the space in the patient between the
above-mentioned two endpoints. The graft is installed along a path
initially defined by structure 600. The invention does not rely on
tunneling through tissue masses in the patient to provide a path
for the graft.
[0129] It will be understood that the foregoing is only
illustrative of the principles of the invention and that various
modifications can be made by those skilled in the art without
departing from the scope and spirit of the invention. For example,
the invention can be used to add a graft to the patient's
circulatory system elsewhere than between the aorta and a coronary
artery as has been specifically shown and described above.
Similarly, although particular examples of connector types have
been shown herein, many other forms of connectors can be used
instead if desired.
* * * * *