U.S. patent application number 12/179943 was filed with the patent office on 2009-01-01 for methods and devices for placing a conduit in fluid communication with a target vessel.
Invention is credited to Wally S. Buch, Darin C. Gittings, Alan R. Rapacki, Adam Sharkawy.
Application Number | 20090005852 12/179943 |
Document ID | / |
Family ID | 32303705 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090005852 |
Kind Code |
A1 |
Gittings; Darin C. ; et
al. |
January 1, 2009 |
Methods and Devices for Placing a Conduit in Fluid Communication
with a Target Vessel
Abstract
Methods and devices for placing a conduit in fluid communication
with a target vessel and a source of blood, such as the aorta or a
heart chamber. The device may be actuated using one hand to place
the conduit. The invention allows air in the conduit to be removed
prior to placement of the conduit. The invention deploys the
conduit in the target vessel by moving a sheath in a distal
direction and then in a proximal direction. A conduit is provided
with a reinforcing member to prevent kinking of the conduit, and a
structure for preventing blockage of the conduit by tissue. A
vessel coupling may be used to secure a conduit to a target vessel
so as to preserve native blood flow through the vessel, and the
conduit may be placed in fluid communication with a target vessel
via a laparoscopic or endoscopic procedure.
Inventors: |
Gittings; Darin C.;
(Sunnyvale, CA) ; Rapacki; Alan R.; (Redwood City,
CA) ; Sharkawy; Adam; (Redwood City, CA) ;
Buch; Wally S.; (Atherton, CA) |
Correspondence
Address: |
MEDTRONIC, INC.
710 MEDTRONIC PARKWAY NE
MINNEAPOLIS
MN
55432-9924
US
|
Family ID: |
32303705 |
Appl. No.: |
12/179943 |
Filed: |
July 25, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10441256 |
May 19, 2003 |
|
|
|
12179943 |
|
|
|
|
09850883 |
May 7, 2001 |
7025773 |
|
|
10441256 |
|
|
|
|
09304140 |
May 3, 1999 |
|
|
|
09850883 |
|
|
|
|
09232103 |
Jan 15, 1999 |
|
|
|
09304140 |
|
|
|
|
09232062 |
Jan 15, 1999 |
|
|
|
09232103 |
|
|
|
|
Current U.S.
Class: |
623/1.11 ; 604/8;
623/1.14 |
Current CPC
Class: |
A61F 2002/91525
20130101; A61B 2017/1107 20130101; A61F 2002/91541 20130101; A61F
2/07 20130101; A61F 2230/0054 20130101; A61F 2/86 20130101; A61F
2/064 20130101; A61B 2017/00252 20130101; A61B 2017/00867 20130101;
A61F 2002/91508 20130101; A61B 2017/1205 20130101; A61F 2/95
20130101; A61F 2/91 20130101; A61B 2017/2923 20130101; A61F 2/9517
20200501; A61B 2017/00243 20130101; A61F 2220/0008 20130101; A61F
2220/005 20130101; A61F 2002/91516 20130101; A61F 2002/91558
20130101; A61F 2/915 20130101; A61F 2220/0075 20130101; A61B 17/11
20130101; A61B 2017/1135 20130101; A61F 2220/0058 20130101 |
Class at
Publication: |
623/1.11 ; 604/8;
623/1.14 |
International
Class: |
A61F 2/84 20060101
A61F002/84; A61M 1/00 20060101 A61M001/00; A61F 2/06 20060101
A61F002/06 |
Claims
1-59. (canceled)
60. A method for performing bypass on a vessel by placing the
vessel in fluid communication with a heart chamber containing
blood, the method comprising steps of: (a) providing a first vessel
having a lumen, the first vessel being sized and configured for
being joined to a second vessel having a lumen that is at least
partially obstructed; (b) placing at least a portion of the first
vessel adjacent the lumen of the second vessel downstream of the
obstruction so as to place the lumens of the first and second
vessels in fluid communication; (c) fixing the first vessel in
position with respect to the lumen of the second vessel without
using suture to form a substantially suture-free anastomosis
between the first and second vessels; and; (d) placing the first
vessel in fluid communication with a heart chamber containing blood
so as to deliver blood from the heart chamber to the lumen of the
second vessel.
61. The method of claim 60, further comprising a vessel coupling
secured to the first vessel and configured to be anastomosed to the
second vessel without suture.
62. The method of claim 61, wherein the vessel coupling is an
expandable conduit that is placed at least partially into the lumen
of the second vessel and expanded to engage the second vessel and
form the anastomosis.
63. The method of claim 62, wherein the expandable conduit is a
stent secured to the first vessel by suture and step (c) is carried
out without using any suture.
64. The method of claim 63, wherein the first vessel comprises a
combination of autologous tissue and synthetic graft material
adapted to be anastomosed to a coronary artery.
65. The method of claim 64, wherein the heart chamber is the left
ventricle.
66. The method of claim 65, wherein the first vessel communicates
with the left ventricle via a flow path passing through the
myocardium.
67. The method of claim 65, wherein the anastomosis is formed to
permit native blood flow through the coronary artery to flow past
the site of anastomosis.
68. A method for bypassing an obstruction in a coronary artery by
placing the coronary artery in fluid communication with a heart
chamber containing blood, the method comprising steps of: (a)
providing a stent-graft assembly including a stent movable between
expanded and non-expanded orientations and a graft vessel attached
to the stent, wherein the graft vessel has a lumen in fluid
communication with the stent; (b) forming an opening in the wall of
the coronary artery that is sized to allow at least a portion of
the stent to be positioned in the lumen of the coronary artery when
the stent is in the non-expanded orientation; (c) positioning at
least a portion of the stent in the lumen of the coronary artery
and expanding the stent into contact with the coronary artery to
form a substantially suture-free anastomosis between the graft
vessel and the coronary artery; and (d) placing the graft vessel in
communication with a heart chamber containing blood.
69. The method of claim 68, wherein the stent is loaded on a
balloon in the non-expanded orientation and the balloon is expanded
during step (c).
70. The method of claim 68, wherein the stent-graft assembly is
secured to the coronary artery without completely occluding the
lumen of the coronary artery so as to allow blood flowing in the
coronary artery to flow past the site of the anastomosis.
71. A device for forming an anastomosis between a graft vessel and
a target vessel during a bypass procedure in which the target
vessel is placed in fluid communication with a heart chamber
containing blood, the device comprising: a vessel coupling
configured to secure a graft vessel to a target vessel, the vessel
coupling having a lumen and being movable between expanded and
non-expanded orientations; a graft vessel secured to the vessel
coupling with the lumens of the graft vessel and the vessel
coupling in fluid communication, a portion of the graft vessel
being adapted to be placed in fluid communication with a heart
chamber containing blood; wherein the vessel coupling is sized and
configured to fit at least partially within the lumen of a coronary
artery in said non-expanded orientation and to engage the coronary
artery in said expanded orientation.
72. The device of claim 71, further comprising a support member
supporting the vessel coupling and the graft vessel, the support
member adapted to be at least partially placed in the lumen of the
target vessel.
73. The device of claim 72, wherein the expansion mechanism
comprises a balloon carried by the support member, and further
comprising means for coupling the balloon to a source of
pressurized fluid for expanding the vessel coupling to the expanded
orientation.
74. The device of claim 73, wherein the vessel coupling is a stent
and the graft vessel comprises a combination of autologous tissue
and synthetic graft material.
75. The device of claim 74, further comprising a sheath overlying
the vessel coupling and the graft vessel, the sheath comprising a
peel-away sheath that is torn and removed to selectively expose the
vessel coupling and the graft vessel.
76. The device of claim 71, wherein the vessel coupling is
configured with a plurality of open areas to permit blood flowing
through the target vessel to flow past the vessel coupling after
forming the anastomosis.
77. A device for performing a bypass procedure in which a
suture-free anastomosis is formed between a graft vessel and a
coronary artery, and wherein the graft vessel is placed in
communication with a heart chamber containing blood to deliver
blood from the heart chamber to the coronary artery, the device
comprising: a stent-graft assembly including a stent movable
between collapsed and expanded orientations and a graft vessel
having a lumen, wherein the stent is secured to the graft vessel
with the lumen of the graft vessel is in fluid communication with
the stent; and an expansion mechanism for expanding the stent to
the expanded orientation once the stent has been at least partially
positioned in the lumen of a coronary artery; wherein the stent and
graft vessel are sized and configured to be collapsed for placement
in the lumen of the coronary artery and then expanded to cause the
stent to engage the wall of the coronary artery to anasotmose the
stent-graft assembly to the coronary artery without suture.
78. The device of claim 77, wherein the stent-graft assembly is
configured to permit blood flowing through the coronary artery from
the aorta to move past the site of the anastomosis.
79. A method for placing a target vessel in fluid communication
with a heart chamber containing blood while preserving native blood
flow through the target vessel, the method comprising steps of: (a)
providing a graft vessel selected from the group consisting of
tissue grafts, synthetic grafts, and grafts formed of both tissue
and synthetic material, wherein the graft vessel has a lumen and is
adapted to be secured to a target vessel having a lumen; (b) fixing
at least a portion of the graft vessel to the target vessel without
using suture to form a substantially suture-free anastomosis
between the graft and target vessels that is distal to the
obstruction in the target vessel; (c) placing the graft vessel in
fluid communication with a heart chamber containing blood; and (d)
allowing any native blood flow in the target vessel to move past
the site of the anastomosis.
80. The method of claim 79, further comprising securing a vessel
coupling to the graft vessel and anastomosing the vessel coupling
to the second vessel without using suture.
81. The method of claim 80, wherein the graft vessel comprises a
synthetic portion in communication with the target vessel and a
tissue portion in communication with the heart chamber.
82. The method of claim 80, wherein the tissue portion of the graft
vessel comprises a section of saphenous vein while the synthetic
portion of the graft vessel comprises a section of ePTFE.
83. The method of claim 79, wherein the vessel coupling comprises
an expandable conduit disposed over an expansion mechanism, and
step (b) is carried out by expanding the expansion mechanism to
force the expandable conduit against the target vessel.
84. The method of claim 79, wherein the vessel coupling comprises a
frame configured to be retained within the lumen of the target
vessel while not blocking blood flow in the target vessel, and the
frame is collapsed for insertion into the target vessel and then
expanded against the wall of the target vessel.
85. The method of claim 79, wherein step (b) is carried out without
suturing the graft vessel to the target vessel.
86. The method of claim 79, further comprising coupling an end of
the graft vessel to a tubular element adapted to communicate with
the heart chamber, and fixing the tubular element to the myocardium
so as to extend into the heart chamber and place the graft vessel
in fluid communication with the heart chamber.
87. A device for performing a bypass procedure in which a target
vessel is place din communication with a heart chamber containing
blood and an anastomosis is formed between a graft vessel and the
target vessel that allows native blood flow through the target
vessel, the device comprising: a graft vessel adapted to be
anastomosed to a target vessel and placed in communication with a
heart chamber containing blood; a vessel coupling secured to the
graft vessel, wherein the vessel coupling has a lumen and is
configured to be anastomosed to the target vessel to place the
graft and target vessels in fluid communication; and wherein the
vessel coupling is secured to the graft vessel so as to allow blood
flow through the target vessel to move past the site of the
anastomosis.
88. The device of claim 87, wherein the vessel coupling comprises a
first portion secured to the graft vessel and a second portion
sized and configured to engage the interior of the wall of the
target vessel to fix the vessel coupling in place.
89. The device of claim 88, wherein the first portion of the vessel
coupling comprises a stent and the second portion of the vessel
coupling comprises a plurality of coils that engage the lumen of
the target vessel.
90. The device of claim 87, further comprising a support member
supporting the vessel coupling and the graft vessel, wherein the
support member is adapted to be at least partially placed in the
lumen of the target vessel.
91. The device of claim 87, further comprising a removable sheath
overlying the vessel coupling and the graft vessel.
92. The device of claim 87, wherein the vessel coupling is
configured to be fixed to the target vessel without suture to form
a suture-free anastomosis.
93. A device for use in performing a bypass procedure in which a
first vessel is placed in fluid communication with a heart chamber
containing blood and anastomosed to a second vessel with a lumen
containing an obstruction, the device comprising: a vessel coupling
including first and second portions for forming an anastomosis
between a first vessel and a second vessel; wherein the first
portion of the vessel coupling is configured to be coupled to a
first vessel that is in fluid communication with a heart chamber
containing blood so that blood flows from the heart chamber and
through the coupling; and wherein the second portion of the vessel
coupling is configured to be secured to a second vessel without
using suture to form a substantially suture-free anastomosis that
allows native blood flow through the second vessel to move past the
site of the anastomosis.
94. The device of claim 93, wherein at least the second portion of
the vessel coupling is formed of a shape memory allow and is
collapsed for introduction into the second vessel and then expanded
to engage the wall of the second vessel to form the anastomosis.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/850,883, filed May 7, 2001, which is a
continuation of U.S. patent application Ser. No. 09/304,149, filed
May 3, 1999, which is a continuation-in-part of application Ser.
No. 09/232,103, filed on Jan. 15, 1999 and entitled "Methods and
Devices for Forming Vascular Anastomoses," the entire subject
matter of which is incorporated herein by reference. This
application is also a continuation-in-part of application Ser. No.
09/232,062, filed on Jan. 15, 1999 and entitled "Methods and
Devices For Bypassing an Obstructed Target Vessel by Placing the
Vessel in Communication with a Heart Chamber Containing Blood," the
entire subject matter of which is also incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to methods and devices for placing a
conduit in fluid communication with a lumen of a target vessel, and
more particularly methods and devices for placing such a conduit in
fluid communication with a target vessel and a source of blood.
[0004] 2. Description of the Related Art
[0005] Despite the considerable advances that have been realized in
cardiology and cardiovascular surgery, heart disease remains the
leading cause of death throughout much of the world. Coronary
artery disease, or arteriosclerosis, is the single leading cause of
death in the United States today. As a result, those in the
cardiovascular field continue to search for new and improved
treatments.
[0006] Coronary artery disease is currently treated by
interventional procedures such as percutaneous transluminal
coronary angioplasty (PTCA), atherectomy and coronary stenting, as
well as surgical procedures including coronary artery bypass
grafting (CABG). The goal of these procedures is to reestablish or
improve blood flow through occluded (or partially occluded)
coronary arteries, and is accomplished, for example, by enlarging
the blood flow lumen of the artery or forming a bypass that allows
blood to circumvent the occlusion. What procedure(s) is used
typically depends on the severity and location of the blockages.
When successful, these procedures restore blood flow to myocardial
tissue that had not been sufficiently perfused due to the
occlusion.
[0007] Another treatment that has been recently proposed places the
target vessel in fluid communication with a heart chamber, for
example, the left ventricle. The target vessel and the heart
chamber may be communicated by a conduit passing through the
myocardium. Some of the challenges associated with such procedures
include proper positioning of the conduit in the myocardium as well
as correct placement of the conduit in a coronary artery.
[0008] As shown by these and other attempts to develop new and
improved treatments that may be used to deliver blood to myocardial
tissue, there remains a need in the art for methods and devices
that may be used to place a conduit in fluid communication with a
target vessel and a source of blood.
SUMMARY OF THE INVENTION
[0009] According to one embodiment of the invention, methods and
devices are provided for placing a conduit in fluid communication
with a target vessel. One preferred method includes steps of
providing a conduit having a first end, a second end and a lumen,
the conduit being supported by a conduit delivery device. A portion
of the device is positioned adjacent a target vessel in a patient's
vascular system, one of the first and second ends of the conduit is
placed in fluid communication with the target vessel, and the
conduit is removed from the delivery device. The steps of
positioning the portion of the conduit delivery device adjacent the
target vessel and placing one of the first and second ends of the
conduit in fluid communication with the target vessel are performed
using one hand.
[0010] One preferred device includes a conduit having a first end,
a second end and a lumen, wherein the conduit is movable between
deployed and non-deployed positions and one end of the conduit is
adapted to be placed in fluid communication with a target vessel. A
sheath overlies at least a portion of the conduit and holds the
portion in the non-deployed position. A first actuator imparts
relative movement to the conduit and the sheath in order to allow
the portion of the conduit to move to the deployed position. A
sheath removal mechanism is provided for removing the sheath after
the conduit has moved to the deployed position. The first actuator
and the sheath removal mechanism are operable using one hand to
place the conduit in fluid communication with the target vessel and
remove the sheath from the target vessel.
[0011] According to another embodiment of the invention, methods
and devices are provided for placing a conduit in fluid
communication with a target vessel and a source of blood. One
preferred method includes steps of providing a conduit having a
first end, a second end and a lumen, placing the first end of the
conduit in fluid communication with the source of blood, allowing
blood to flow into the lumen of the conduit to force substantially
all air from the conduit, and placing the second end of the conduit
in fluid communication with the target vessel.
[0012] One preferred device includes a conduit having a first end,
a second end and a lumen, wherein the first end of the conduit is
adapted to be placed in fluid communication with a target vessel
and the second end of the conduit is adapted to be placed in
communication with a source of blood. A support shaft has a section
that is removably coupled to the first end of the conduit for
placing the first end of the conduit in fluid communication with
the target vessel, but de-coupled from the second end of the
conduit to allow the second end of the conduit to be placed in
communication with the source of blood prior to placing the first
end of the conduit in fluid communication with the target
vessel.
[0013] According to another embodiment of the invention, methods
and devices are provided for establishing a conduit to place a
coronary vessel in fluid communication with a heart chamber
containing oxygenated blood. One preferred method includes steps of
placing a conduit in fluid communication with a heart chamber
containing oxygenated blood, wherein at least a major portion of
the length of the conduit is disposed exterior to the heart wall.
The conduit is also placed in fluid communication with a lumen of a
coronary vessel, and is secured to the coronary vessel by a sutured
anastomosis so as to place the coronary vessel in fluid
communication with the heart chamber.
[0014] According to another embodiment of the invention, methods
and devices are provided for deploying a conduit in a target
vessel. One preferred method includes steps of providing a conduit
having a first end, a second end and a lumen, wherein the conduit
is movable between deployed and non-deployed positions and at least
a portion of the conduit is held in the non-deployed position by a
retention member. At least the non-deployed portion of the conduit
is placed in a lumen of a target vessel, and the retention member
is moved in a first direction with respect to the conduit to move
the non-deployed portion of the conduit to the deployed position.
The retention member is moved in a second direction that is
substantially opposite the first direction to remove the retention
member from the target vessel.
[0015] One preferred device includes a conduit having a first end,
a second end and a lumen, wherein the conduit is movable between
deployed and non-deployed positions and one end of the conduit is
adapted to be placed in fluid communication with a target vessel. A
retention member overlies at least a portion of the conduit to hold
the portion in the non-deployed position. An actuator is coupled to
the retention member and is moved in a first direction to move the
retention member and allow the portion of the conduit to move to
the deployed position. The actuator is then moved in a second
direction to remove the retention member from the target vessel,
the second direction being transverse to the first direction.
[0016] According to another embodiment of the invention, methods
and devices are provided for placing a conduit in fluid
communication with a target vessel while preserving native blood
flow through the target vessel. One preferred method includes steps
of providing a vessel coupling and a conduit, wherein the vessel
coupling has a first portion configured to secure the conduit to a
target vessel so that the conduit is in fluid communication with
the target vessel. The vessel coupling is moved generally along a
first direction to place the first portion of the vessel coupling
at least partially within the lumen of the target vessel, and the
first portion of the vessel coupling is then moved generally along
a second direction within the lumen of the target vessel to deploy
the vessel coupling and secure the conduit to the target vessel,
wherein the second direction is transverse to the first
direction.
[0017] One preferred device includes a vessel coupling including a
first portion joined to a second portion, wherein the first portion
of the vessel coupling is sized and configured to be attached to a
target vessel while allowing native blood flow through the target
vessel to move past the site of attachment. The second portion of
the vessel coupling is sized and configured to be coupled to a
conduit that is adapted to form a flow path between the target
vessel and a source of blood. The first portion of the vessel
coupling includes a plurality of support members sized and
configured to engage a wall of the target vessel, each support
member including a plurality of generally straight support
struts.
[0018] According to another embodiment of the invention, methods
and devices are provided for forming a blood flow path through
tissue. One preferred device includes a tubular member having a
first end, a second end and a lumen, wherein the tubular member is
configured to be placed in tissue and the lumen of the tubular
member is sized and configured to receive a conduit adapted to form
a blood flow path through the tissue. At least one of the first and
second ends of the tubular member is configured to extend through
the tissue so as to place the conduit in fluid communication with a
hollow body structure containing blood, and a structure is coupled
to the one end of the tubular member for maintaining the one end
substantially open. The structure includes at least one opening
through which blood from the hollow body structure may enter the
conduit.
[0019] According to another embodiment of the invention, methods
and devices are provided for placing a conduit in fluid
communication with a target vessel in a patient's vascular system
by passing a device through a port located between adjacent ribs.
One preferred method includes steps of providing a conduit having a
first end, a second end and a lumen, wherein the conduit is
supported by a conduit delivery device having a portion that is
sized and configured to be passed through a port located between
adjacent ribs in a patient's body, and passing the portion of the
conduit delivery device through the port to a location adjacent the
target vessel. One of the first and second ends of the conduit is
placed in fluid communication with a lumen of the target vessel,
the conduit is removed from the conduit delivery device, and the
conduit delivery device is removed from the port.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0020] Various other aspects, features, benefits and advantages of
the invention will be better understood from the following detailed
description of preferred embodiments thereof, taken in conjunction
with the accompanying drawing figures, wherein:
[0021] FIG. 1 is a perspective view of a device constructed
according to one embodiment of the invention for placing a conduit
in fluid communication with a target vessel;
[0022] FIG. 2 is an exploded perspective view of the device shown
in FIG. 1;
[0023] FIG. 3 is a longitudinal sectional view of the device shown
in FIG. 1;
[0024] FIGS. 3A and 3B are transverse sectional views taken,
respectively, along lines A-A and B-B in FIG. 3;
[0025] FIG. 4 is an enlarged, fragmentary longitudinal sectional
view of the device shown in FIGS. 1 and 3;
[0026] FIGS. 5A-5D are sectional views sequentially illustrating an
exemplary use of the device shown in FIG. 3;
[0027] FIG. 6 is a perspective view of a conduit that has been
placed in fluid communication with a target vessel as shown in
FIGS. 5A-5D, the conduit including a vessel coupling disposed on
the exterior of the conduit;
[0028] FIG. 6A is a perspective view of the conduit shown in FIG.
6, wherein the vessel coupling is shown disposed within the
conduit;
[0029] FIG. 7 is a perspective view of a conduit that has been
placed in fluid communication with a target vessel and a source of
blood according to another embodiment of the invention, wherein the
source of blood is the aorta;
[0030] FIG. 8 is a perspective view of a conduit that has been
placed in fluid communication with a target vessel and a source of
blood according to another embodiment of the invention, wherein the
source of blood is the left ventricle and the conduit has an end
configured to be placed in the myocardium;
[0031] FIG. 9 is an enlarged perspective view of an end of the
conduit that is shown placed in the left ventricle in FIG. 8;
[0032] FIG. 10 is a perspective view of a fitting mounted to the
end of the conduit shown in FIG. 9;
[0033] FIG. 11 is a sectional view illustrating the end of the
conduit shown in FIG. 9 placed in the myocardium;
[0034] FIG. 12 is a sectional view of a portion of a conduit
constructed according to another embodiment of the invention,
wherein the end of the conduit is configured for placement in the
myocardium;
[0035] FIG. 12A is an enlarged view of the portion encircled in
FIG. 12;
[0036] FIG. 13 is a perspective view of a device constructed
according to another embodiment of the invention, wherein the
device includes the conduit shown in FIG. 9;
[0037] FIG. 14 is a perspective view of a device constructed
according to another embodiment of the invention for placing a
conduit in fluid communication with a target vessel and a source of
blood, wherein the device allows placement of either end of the
conduit first;
[0038] FIG. 15 is a perspective view of a device constructed
according to yet another embodiment of the invention for placing a
conduit in fluid communication with a target vessel, wherein the
device is sized and configured for use in a laparoscopic or
endoscopic procedure;
[0039] FIG. 16 is a perspective view illustrating the device shown
in FIG. 15 being used in a minimally invasive procedure.
[0040] FIG. 17 is a perspective view of a conduit that has been
placed in fluid communication with a target vessel according to
another embodiment of the invention, wherein native flow through
the target vessel is substantially preserved;
[0041] FIG. 18 is a perspective view of a conduit including a stent
constructed according to another embodiment of the invention,
wherein the stent places the conduit in fluid communication with a
target vessel so as to substantially preserve native flow through
the target vessel;
[0042] FIG. 19 is a flat pattern elevation view showing one end of
the stent shown in FIG. 15;
[0043] FIG. 20 is a perspective view of a conduit including a stent
constructed according to another embodiment of the invention,
wherein the stent places the conduit in fluid communication with a
target vessel so as to substantially preserve native flow through
the target vessel; and
[0044] FIG. 21 is a flat pattern elevation view showing one end of
the stent shown in FIG. 20.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0045] Referring to FIGS. 1-4, a device constructed according to
one preferred embodiment of the invention is indicated generally by
the reference numeral 10. The device 10 is used to place a conduit
in fluid communication with a target vessel, the conduit also
preferably being placed in fluid communication with a source of
blood. As used herein, source of blood refers to any structure
containing blood, although a structure containing oxygenated blood,
i.e., blood containing some level of oxygen, is preferred. For
example, the source of blood may be a heart chamber while the
target vessel may be a coronary artery or vein or another
vessel.
[0046] The device 10 comprises a handle 12, a shaft assembly 14 and
an actuator assembly 16 (FIGS. 2-4). The shaft assembly 14 may be
relatively flexible to permit it to bend during use, or it may be
substantially rigid. The degree of flexibility imparted to the
shaft assembly 14 of the device 10, as well as the dimensions and
shape of the device 10, may vary depending on the particular
application and user preference.
[0047] The device 10 could be formed with a shaft assembly 14 that
is curved, malleable or bendable to a selected configuration, or
articulated with a movable portion that may be controlled or
steered by known mechanisms, for example, mechanisms used to steer
catheters or guide wires. As an example, the device could have a
curved shaft assembly constructed according to the teachings in
co-pending, commonly-owned application Ser. No. 09/304,141
(attorney docket no. 008), filed on May 3, 1999 and entitled
"Methods and Devices for Forming a Conduit Between a Target Vessel
and a Blood Source," the entire subject matter of which is hereby
incorporated by reference.
[0048] The application of the invention illustrated in the Figures
places a conduit in fluid communication with a target vessel and a
source of blood. The term conduit refers to a flow path established
between the target vessel and the blood source and includes
structure that defines (either partially or completely) the flow
path. A conduit constructed according to the invention may comprise
one or more sections, each of which sections may comprise various
materials. It will be appreciated that the specific conduit
configurations illustrated in connection with preferred embodiments
described herein is for sake of example and is not intended to
limit the scope or application of the invention.
[0049] The illustrated conduit 18 includes a proximal end 20, a
distal end 22 and a lumen 24. The conduit 18 is deployed in a
target vessel and preferably includes a vessel coupling that is
configured to be secured to the target vessel. It should be
understood, however, that the invention may be practiced without
using a vessel coupling, for example, by securing the conduit to
the target vessel with a sutured anastomosis created by hand or an
automated suturing device, biologically compatible adhesives,
fasteners, etc. A vessel coupling is preferred, however, to
facilitate relatively easy and rapid attachment of the conduit to
the target vessel as compared to creating a hand-sewn anastomosis.
Also, the conduit may comprise tissue, synthetic vascular graft
material, or a combination of tissue and synthetic vascular graft
material. Thus, in a basic embodiment, the invention could comprise
a tissue or synthetic conduit that is placed in communication with
a source of blood such as the left ventricle, and hand-sutured to a
target vessel such as a coronary artery.
[0050] In the illustrated embodiments, the conduit 18 comprises a
length of synthetic vascular graft material, such as ePTFE, PTFE or
Dacron, or another material that may be used to form a conduit that
conveys blood, for example, silicone, PVA or polyurethane. The
proximal end 20 of the conduit 18 is adapted to be placed in fluid
communication with a source of blood (not shown in FIGS. 1-4) and
for that purpose may include means for securing the conduit in
place with respect to the blood source, such as a device configured
to be implanted and fixed in tissue located adjacent the blood
source. Alternatively, the proximal end 20 of the conduit 18 could
be secured to tissue by other means, for example, any of the
aforementioned means for securing the distal end of the conduit 18
to the target vessel.
[0051] In the most preferred embodiment, the conduit is secured to
the target vessel by a substantially suture-free attachment, which
means that the attachment is not a conventional hand-sewn
anastomosis created by suturing the members together. As such,
although some suture may be used in the preferred embodiment, the
vessel coupling is attached to the target vessel by means other
than a typical, hand-sewn sutured connection. The invention,
however, may be practiced using suture as the means for attaching a
conduit comprising tissue or synthetic vascular graft material to a
target vessel.
[0052] The conduit 18 includes a vessel coupling that attaches the
conduit to the target vessel, the vessel coupling preferably being
expandable so that it may be collapsed for introduction into the
vessel and then expanded against the vessel wall. It will be
understood, however, that the invention may be practiced with a
non-expandable vessel coupling, such as a rigid tubular member
securely engaged with the wall of the target vessel, for example,
by first dilating the vessel wall to place the element and then
allowing the vessel wall to move back and snugly engage the
exterior of the element.
[0053] The expandable vessel coupling moves between collapsed and
expanded orientations and in the preferred embodiment comprises a
stent 26. The stent 26 could be formed of various materials
including nitinol, stainless steel, tantalum or titanium. As an
example, the stent 26 may be a self-expanding nitinol stent joined
to a liner or layer 28 of teflon (PTFE) or expanded teflon (ePTFE)
to form the conduit 18. The stent 26 preferably includes a
plurality of struts that permit the stent to collapse and expand,
although other stent constructions may be used; for example, the
stent could be wire-formed or could comprise a flat sheet of
material that is unrolled to an expanded orientation.
[0054] As an example, the stent may be formed by subjecting a tube
of suitable material to any of various procedures such as laser
cutting, EDM (electrical discharge machining), photochemical
etching, etc. The stent/tube material is preferably nitinol, but
may be titanium, tantalum, etc. It may be desirable to further
process or finish the cut stent to remove burrs or surface
irregularities, for example, by acid etching, electropolishing, or
abrasive blasting. The stent may then be placed in its collapsed
orientation by cooling (e.g., with liquid nitrogen), coupled to a
liner and loaded onto a delivery device, and then deployed in a
target vessel. The liner of the conduit, for example, may comprise
ePTFE having an inner diameter within the range of from about 1 mm
to about 5 mm, and more preferably about 2 mm to about 4 mm, a wall
thickness of about 0.2 mm, and an internodal distance or pore size
in the range of from about 20 .mu.s to about 100 .mu.s.
[0055] The liner 28 is secured to the stent 26 by any suitable
means, for example, one or more lengths of suture (not shown) that
pass through the liner wall and the wall of the stent. Other
suitable means for securing the two components include biologically
compatible adhesives, ultrasonic welding, clips or fasteners,
weaving the liner through the stent elements, tying the liner to
the stent elements, etc. As shown in FIG. 2, the stent 26 is
preferably aligned so as to extend a desired amount along part of
the distal end 22 of the conduit 18. This relative position is
preferred as it allows part of the stent 26 to extend through the
wall of the target vessel when the conduit 18 has been deployed,
this portion of the stent serving to hold the junction open to
maintain fluid communication. However, it will be appreciated that
the stent 26 and liner 28 could overlap to a lesser or greater
extent than that shown in the Figures, and the stent may or may not
extend through the target vessel wall.
[0056] For example, the stent 26 could extend along substantially
the entire length of the conduit 18, along only the two end
portions of the conduit, or the conduit could include discrete
sections that comprise only stent or liner material. In the
exemplary embodiment shown in FIGS. 1-4, the conduit 18 has a
distal section defined by stent and liner material while the
remaining length of the conduit 18 is defined by liner material
alone (as seen from FIGS. 3A-3B). Also, while the stent 26 is shown
disposed outside the liner 28 in FIGS. 1-4, it will be recognized
that the stent may be disposed within the liner. Finally, while the
illustrated conduit 18 includes only the stent 26 and a single
liner 28, an additional layer(s) of material, such as another layer
of PTFE or ePTFE, a layer of silicone, or another stent, may be
included as well.
[0057] Referring to FIG. 2, the conduit 18 is supported by the
shaft assembly 14, and more particularly by a support member 30
which forms part of the shaft assembly 14. The support member 30
may be a rod or shaft that is sized and configured to mount the
conduit 18, and more specifically the stent 26 and liner 28. FIG. 2
shows (in phantom) the conduit 18 mounted on the support member 30
in its collapsed orientation. The support member 30 has a proximal
end 32 and a distal end 34, the proximal end 32 being fixed to the
handle 12 (as shown in FIGS. 3-4). The distal end 34 is preferably
provided with a stop for maintaining the conduit 18 in position.
The stop may be in the form of a piston 36 carried by the support
member 30 and sized to generally correspond to the collapsed
diameter of the conduit 18. The illustrated support member 30 also
includes a bore 38 extending through the length of the member (FIG.
2).
[0058] In the illustrated embodiment, the bore 38 in the support
member 30 receives a shaft 40 provided with a retention mechanism
for retaining all or a portion of the conduit 18 (and in particular
the stent 26) in its collapsed orientation during introduction into
the lumen of the target vessel. A preferred retention mechanism
comprises a sheath 42 sized and configured to be placed over a
collapsed portion of the conduit 18. A nose cone dilator having one
or more tapered surfaces for introducing the device into the lumen
of a target vessel is preferably disposed on the shaft 40 distal to
the sheath 42. The nose cone dilator may comprise any suitable
material, a soft, floppy atraumatic material being preferred. It
should be noted that alternative or additional means for dilating
the vessel may be used or the dilator may be omitted altogether,
although some form of dilator is preferably used. The sheath 42 is
preferably fixed to the shaft 40 but could instead be removably
supported by the shaft. The sheath 42 may be formed of any suitable
thin-walled, flexible material, e.g., polyolefin, nylon, polyimide,
PEEK, or Hytrel.
[0059] It will be appreciated that the sheath could be constructed
so as to be removable in a manner the same as or similar to that
disclosed in co-pending, commonly-owned application Ser. No.
09/232,103, filed on Jan. 15, 1999 and entitled "Methods and
Devices for Forming Vascular Anastomoses," or co-pending,
commonly-owned application Ser. No. 09/232,062, filed on Jan. 15,
1999 and entitled "Methods and Devices For Bypassing an Obstructed
Target Vessel by Placing the Vessel in Communication with a Heart
Chamber Containing Blood," the subject matter of which applications
has been incorporated herein by reference.
[0060] Additionally, the sheath could be constructed according to
the disclosure in co-pending, commonly-application Ser. No.
09/304,141 (attorney docket no. 008), filed on May 3, 1999 and
entitled "Methods and Devices for Forming a Conduit Between a
Target Vessel and a Blood Source," the entire subject matter of
which application is incorporated herein by reference.
[0061] As shown in FIG. 2, the proximal portion of the shaft 40 is
in the form of a rack 44 which forms part of the actuator assembly
16. The actuator assembly 16 is used to impart relative movement to
the conduit 18 and sheath 42 in order to deploy the conduit 18 in
the target vessel. The rack 44 has teeth for engaging the teeth of
a pinion 46 carried by an actuator 48. In the illustrated
embodiment, the actuator 48 is a lever pivotally coupled to the
handle 12 by a pivot pin 50. The actuator 48 is pivoted with
respect to the handle 12 and transmits motion to the shaft 40 via
the mating gear teeth on the rack 44 and pinion 46. The actuator
assembly 16 is constructed so that pivoting the actuator 48 moves
the shaft 40 and sheath 42 a desired amount in a desired direction
to deploy the conduit, which according to the preferred embodiment
may be done using one hand, as described more fully below. Other
methods of actuation may of course be used, such as those using
cable systems, alternative lever assemblies, etc. The device 10
also preferably includes a locking mechanism which may be in the
form of a safety pin 52 movably disposed in a bore 54 in the handle
12. The safety pin 52 can be moved into or out of a mating bore 56
formed in the actuator 48 to either lock or unlock the actuator 48
with respect to the handle 12.
[0062] The device 10 also includes a mechanism that aids in
removing the device, and in particular the sheath 42, from the
target vessel. A preferred mechanism is indicated generally by the
reference numeral 58 in FIG. 2 and comprises a tubular body 60
having a bore 62 sized to be slid over the support member 30. The
body 60 has a proximal end 64 and a distal end 66, the latter being
provided with a member 68 that is configured to be coupled to the
sheath 42. The member 68 preferably has a tapered contour that
allows the member 68 to be slid into the open end of the sheath 42.
The member 68 may have a groove 70 or other portion that engages
the edge of the sheath 42 to provide a smooth outer profile for
withdrawing the sheath from the lumen of the target vessel.
[0063] The proximal end 64 of the tubular body 62 is provided with
an actuating portion 72 for moving the body 62 and member 68 with
respect to the shaft 40. The actuating portion 72 may be connected
to the tubular body 62 by a stem 74 which extends through a slot 76
formed in the handle 12. The body 62 may be movable in one or more
directions; in the illustrated embodiment, the tubular body 62 is
moved distally (to the left in FIG. 3) along the longitudinal axis
of the device to engage the member 68 and the sheath 42. The entire
device is then moved proximally with the sheath 42 passing through
the conduit 18.
[0064] As can be seen from FIG. 1, the relative position of the
actuator 48 of assembly 16 and the actuating portion 72 of sheath
removal mechanism 58 allows them to be operated using one hand.
Accordingly, a surgeon may place the conduit 18 in fluid
communication with the target vessel, remove the sheath 42 (or
other retention mechanism) from the conduit, and remove the device
10 from the vessel using only one hand. This aspect of the
invention provides the user with a free hand unlike an instrument
requiring two-handed operation, and thus adds flexibility to enable
relatively quick and easy conduit deployment. It will be recognized
that the invention encompasses other device configurations that
allow the conduit to be deployed and/or the device to be removed by
one-handed operation, the particular device shown in the Figures
being merely exemplary.
[0065] FIGS. 3-4 show in more detail the internal construction of
the illustrated device 10. FIG. 3 shows the handle 12 and actuator
assembly 16, while FIGS. 3A, 3B and 4 show details of the shaft
assembly 14. The handle 12 preferably includes a chamber 80 that
receives the rack 44 and pinion 46 of actuator assembly 16 and
allows them to move upon actuation of the device. The rack 44 or
pinion 46 may be constrained by a track or guide so as to move
along a certain path or they may simply be disposed in the chamber
80 in a free-floating manner.
[0066] It should be noted that the device 10 may be introduced into
a target vessel in various ways. For example, in the illustrated
embodiment, the handle 12 of the device 10 is provided with a bore
82 that may receive an incising element (not shown) having a
sharpened tip for penetrating the wall of the target vessel. See
FIG. 3. The bore 82 opens into the chamber 80 and is aligned with a
bore 84 provided in the shaft 40 (or another component of the shaft
assembly 14). The incising element could be a separate component
that is passed through the bores 82, 84; alternatively, the
incising element could be formed as an integral part of the device.
The invention could be used with other incising elements or
components, for instance, the incising assembly disclosed in
application Ser. No. 09/232,103 and application Ser. No.
09/232,062, the entire subject matter of which applications has
been incorporated by reference herein.
[0067] Providing the shaft assembly 14 of the device with the bore
84 allows the incising element to be extended and retracted and
also protects the conduit 18 by limiting or preventing its contact
with other components of the device. Additionally, either or both
of the bores 82, 84 may be configured to act as a flashback lumen
that indicates when the device has entered a lumen containing
blood, for example, a coronary artery or heart chamber. The bores
82, 84 may be disposed to provide blood flash irrespective of
whether the bores receive an incising element or an additional
member(s), for example, means for introducing the device into the
target vessel such as a guide wire or guide catheter. In addition,
it will be appreciated that the device may be used without an
incising element, for example, by placing the shaft assembly
through a surgical incision in the target vessel wall.
[0068] Turning again to FIGS. 3-4, the device 10 is depicted in a
first position (also shown in FIG. 1) wherein the conduit 18 has
not yet been deployed in a target vessel. In this position the
sheath 42 overlies a selected portion of the conduit 18 and holds
the stent 26 and liner 28 in a collapsed orientation. The remaining
portions of the stent 26 and the liner 28 extend outside of the
sheath 42 and assume their expanded orientation. As seen in FIG.
3A, the sheath 42 contacts the outer surface of the portion of the
stent 26 to maintain that portion collapsed. In the illustrated
embodiment, the liner 28 is disposed within stent 26, although, as
noted above this is only one possible construction. Also, the
portion of the liner 28 within the sheath 42 is preferably folded
or otherwise collapsed to a lower profile (although for sake of
clarity FIG. 3A does not show the liner 28 folded to such a
profile).
[0069] The shaft 40 extends through the bore 82 in the handle 12
and is disposed, preferably coaxially, within the bore 38 in the
support member 30. The conduit 18 is loaded on the support member
30 and the desired portion of the conduit is collapsed to a low
profile orientation, the piston 36 abutting the distal end 22 of
the conduit 18. The sheath 42 is placed over the collapsed portion
of the conduit 18 as shown in FIG. 1. The actuator 48 is moved
toward the handle 12 which rotates the pinion 46 and drives the
rack 44 distally (to the left in FIGS. 3-4). This moves the sheath
42 to uncover the stent 26 and deploy the conduit 18. Moving the
sheath 42 in this direction will tend to move the conduit 18 in the
same direction due to friction between the stent 26 and the sheath
42. The piston 36, however, prevents the stent 26 from moving with
the sheath 42 (as the piston is fixed to the handle 12). As a
result, the sheath 42 is moved while the conduit 18, including the
stent 26, remains substantially stationary (and preferably
stationary) with respect to the handle 12.
[0070] In the illustrated embodiment the actuator 48 is pivoted
toward the handle 12; however, the device could be constructed so
that the actuator 48 is moved in a different manner or direction to
deploy the conduit. For example, the actuator assembly 16 could
comprise a trigger-like member that is slideable with respect to
the handle 12, or a pair of scissors-like members that are moved
together (or apart) to actuate the device. An actuator that is
operable using one hand is preferred, although not necessary to
practicing various aspects of the invention. At any rate, the
actuator assembly 16 is preferably coupled to the shaft assembly 14
so as to produce motion that is generally along the longitudinal
axis of the device, thereby providing the device with a small
profile, although a non-longitudinal actuator motion could also be
used.
[0071] FIGS. 5A-5D illustrate an exemplary application of the
device 10 wherein a conduit is placed in fluid communication with a
target vessel TV. FIG. 5A shows the distal portion of the shaft
assembly 14 inserted through an opening in the target vessel wall W
and into the lumen of the target vessel. Although not shown, an
incising component may be used to form the opening in the wall W.
The device 10 is preferably introduced into the lumen by dilating
the opening in the wall W and cannulating the target vessel TV.
[0072] FIG. 5B shows the device after the sheath 42 has been moved
distally to expose the portion of the conduit 18 that is covered by
the sheath in FIG. 5A. The actuator 48 is moved relative to the
handle 12 from the position shown in FIG. 1 to move the sheath 42
and allow the stent 26 to assume its expanded orientation. The
piston 36 prevents the stent 26 from moving distally with the
sheath 42. This step is preferably carried out so as to prevent or
minimize trauma to the target vessel TV, so the nose cone dilator
is formed of a relatively soft and flexible material and has an
atraumatic shape, although stiff or rigid materials may be used as
well. In the position shown in FIG. 5B, the stent 26 is fully
expanded and secures the deployed conduit 18 to the target vessel
TV in fluid communication therewith, preferably via a sealed
connection between the two structures.
[0073] As can be seen from FIG. 5B, the piston 36 is disposed in
(or near) the proximal end of the sheath 42 after the stent 26 has
been deployed in the target vessel TV. As such, the piston 36 may
block the open end of the sheath 42 and interfere with engagement
between the sheath removal mechanism 58 and the sheath 42.
Accordingly, it may be necessary to first impart relative movement
to the piston 36 and the sheath 42 in order to present an open
proximal end of the sheath to the removal mechanism 58. This may be
achieved in various ways. For example, in the illustrated
embodiment the piston 36 is fixed to the handle 12 via support
member 30. The actuator 48 thus may be moved away from the handle
12 to move the sheath 42 proximally with respect to the handle and
the piston 36. Alternatively, the piston 36 could be coupled to the
handle so as to be movable with respect thereto, e.g., by a
separate actuator. In either case the piston 36 is moved relative
to the sheath 42, an exemplary result of such movement being shown
in FIG. 5C.
[0074] It will be recognized that other constructions may of course
be used. For example, rather than imparting relative movement to
the piston 36 and the sheath 42, the sheath removal mechanism 58
could be configured to engage the edge of the sheath 42 without
moving the piston. Also, the mechanism 58 could be configured to
engage the piston 36 directly and provide a smooth outer profile to
the distal portion of the shaft assembly 14.
[0075] FIG. 5C shows the sheath removal mechanism 58 after it has
been moved in the direction of the arrow into engagement with the
open end of the sheath 42 to form a smooth atraumatic profile that
prevents or minimizes damage to the vessel or the conduit 18. In
the illustrated embodiment the edge of the sheath 42 rests in the
groove 70 and transitions into the proximal portion of the member
68. The next step, as shown in FIG. 5D, is to move the shaft
assembly 14 proximally in the direction of the arrow to remove the
device and deploy the conduit 18 in the target vessel TV. The
removal mechanism 58 prevents the sheath from catching on the stent
struts. Removing the device results in a preferably fluid-tight
attachment that communicates the lumen of the conduit 18 with the
lumen of the target vessel TV.
[0076] FIG. 6 is a perspective view of the exterior of the target
vessel TV and the conduit 18. The distal end 22 of the conduit 18
is positioned in the lumen of the target vessel TV with the stent
26 expanded against the vessel wall W. The liner 28 is secured to
the stent 26 and thus is held open by the expanded stent to provide
a fluid path for blood flowing in the direction of the arrows. The
amount of the conduit 18 that is positioned in the lumen of the
target vessel TV may vary from that shown but is preferably
sufficient to ensure a secure attachment between the conduit and
the vessel. Similarly, the amount of the stent 26 that extends
outside the target vessel TV may vary from that shown in FIG. 6.
However, as noted above it may be desirable to allow a sufficient
portion of the stent 26 to extend through the opening in the target
vessel wall to prevent the vessel wall from collapsing the conduit
18.
[0077] FIG. 6A shows an alternative embodiment wherein the stent 26
is disposed on the interior of the conduit 18, and specifically
within the interior of the liner 28. In this arrangement the liner
28 is forced open by the expanded stent to provide an open fluid
path for blood flowing in the direction of the arrows. It should be
noted that in this embodiment the liner 28 may be secured to the
stent 26 less vigorously as the stent presses the liner against the
target vessel wall, as opposed to the stent pulling the liner
toward the wall (as in the embodiment of FIG. 6). It will be
appreciated that other constructions and configurations may be used
as well.
[0078] FIG. 7 is an anterior view of a heart H showing the left
ventricle LV, right atrium RA, aorta A, pulmonary trunk PT and
pulmonary veins PV. The left coronary artery, including the
circumflex branch and the left anterior descending branch LAD, is
visible in this view, as is the right coronary artery RCA. The
coronary arteries run along the heart wall and deliver oxygenated
blood to the myocardial tissue. An occlusion or blockage O
partially (or completely) obstructs the lumen of the LAD, which
results in inadequate or no blood flow to the heart wall tissue fed
by the portion of the LAD that is downstream of the occlusion
O.
[0079] The distal end 22 of the conduit 18 has one end secured to
the LAD (distal to the occlusion O) by the stent 26 as described
above. The proximal end 20 of the conduit 18 is secured to a source
of blood, which in this case is the aorta A. The proximal end 20
may be attached to the aorta A via a sutured anastomosis P created
by an instrument or in a hand-sewn manner. Other means for
attaching the end of the conduit 18 include a vessel coupling such
as a stent, other fasteners, biologically compatible adhesives,
etc. Also, as an example, the length of the conduit extending
between the aorta and the coronary vessel may be in the range of
from about 5 cm to about 8 cm (including the portion of the conduit
disposed in the vessel).
[0080] It will be appreciated that the particular target vessel and
source of blood shown in FIG. 7 is only exemplary as there will be
numerous applications for the methods and devices disclosed herein.
For example, FIG. 8 illustrates a heart wherein the invention has
been used to place a target vessel in fluid communication with an
alternative source of blood. The distal end 22 of the conduit 18 is
secured to the LAD as in FIG. 7; however, the proximal end 20 of
the conduit is placed in fluid communication with a heart chamber
containing blood, which in this embodiment is the left ventricle
LV. As a result, blood flows from the left ventricle LV into the
conduit 18 and into the target vessel distal to the occlusion O. As
an example of one possible configuration, the length of the conduit
extending between the heart chamber and the coronary vessel may be
in the range of from about 3.5 cm to about 5 cm (including the
portion of the conduit disposed in the myocardium).
[0081] FIG. 8 also illustrates a device for securing an end of the
conduit to tissue located adjacent the source of blood. The device
is indicated generally by the reference numeral 90 and is shown in
detail in FIGS. 9-11. FIG. 9 is an enlarged view of the distal end
22 of the conduit 18 coupled to the device 90 as shown in FIG. 8.
FIG. 10 is an enlarged view of a fitting 92 which forms part of the
device 90. FIG. 11 is an enlarged view of a tissue section T
showing one preferred placement of the device 90 so as to
communicate with a source of blood S.
[0082] The fitting 92 preferably comprises a tubular member with
opposite ends opening into a hollow interior. The fitting 92 may be
formed of any suitable material having sufficient strength to
remain open against compressive forces exerted by the tissue.
Suitable materials include stainless steel, titanium, tantalum,
polymers, etc. The dimensions of the fitting 92 may be varied
depending on the particular application and the material(s) used.
As an example, for use in the application illustrated in FIG. 8,
the fitting 92 may be formed from 6 or 8-gauge thin wall 304
stainless steel hypo tube stock with a length of approximately 23
mm and an OD of approximately 5 mm.
[0083] The fitting 92 may be provided with one or more openings 94
for securing the liner 28 to the fitting or better fixing the
position of the fitting in tissue. The fitting 92 also may be
provided with a flange 96 at an end thereof for engaging tissue and
further securing the device 90 in position. As shown in FIG. 10,
another end of the fitting 92 is provided with one or more grooves
98 for use in securing the conduit 18 to the fitting. FIG. 9
illustrates the conduit 18 passed through the interior of the
fitting 92 with the distal end 22 of the conduit everted over the
end of the fitting. In the illustrated embodiment, one or more
lengths of suture extend around the everted distal end 22 of the
conduit 18 and lie in the grooves 98 so as to secure the conduit to
the fitting 92. It will be appreciated that the lengths of suture
may be omitted or replaced by alternative fastening means, for
example, biologically compatible adhesives, clips, bands, wire,
etc.
[0084] The preferred embodiment of the conduit also includes a
component for preventing blockage of the end of the device that is
placed in communication with the source of blood. The component
includes sufficient structure to prevent blockage and at least one
opening through which blood from the source may enter the conduit.
As an example, when placing a conduit in communication with a heart
chamber, such as the left ventricle, an end of the conduit is
positioned in and extends through the myocardium. The conduit end
will move relative to the myocardial tissue, and particularly the
endocardium, which may result in tissue overlying all or a portion
of the open end of the conduit. The end of the conduit that is in
the ventricle will also be located near tissue such as the chordae
tendineae, papillary muscle or other myocardial tissue, thereby
increasing the risk of such tissue blocking blood flow into the
conduit.
[0085] One preferred component for preventing blockage of the
conduit is indicated by the reference numeral 100 in FIGS. 9 and 11
and is provided on the device 90. The component 100 is in the form
of a structure comprising a plurality of struts 102 defining open
areas 104 through which blood may flow. Each strut 102 has one end
106 secured to the fitting 92 while the other ends of the struts
meet at a junction 108. The struts 102 may be formed of various
materials, for example, stainless steel wire or any of the
materials used to form the fitting, and the ends 106 may be secured
to the fitting 92 by any suitable means, e.g., brazing, welding,
adhesives, etc. As an example, the struts 124 may be formed from
304 full hard stainless steel wire with a length of approximately
18 mm and an outer diameter of approximately 0.375 mm. If
constructed as in the illustrated embodiment, the length of the
portion of each strut 124 extending beyond the proximal end 120 of
the vessel 112 may be approximately 8 mm.
[0086] While the illustrated mechanism includes three curved struts
104, fewer or more struts may be used, and the struts may be
straight, curved, or otherwise shaped, and may be rigid or
flexible. Further, it will be readily appreciated that alternative
mechanisms for preventing blockage of the end of the conduit that
communicates with the heart chamber (or other blood source) may be
used in lieu of that illustrated in the Figures. For example,
rather than a plurality of individual struts, the mechanism could
comprise a grid or mesh that allows blood to flow into the
conduit.
[0087] FIG. 11 schematically illustrates one possible orientation
of the device 90 in tissue wherein the flange 96 engages an
exterior surface of the tissue and aids in fixing the device in
position. The openings 94 may be provided in order to enhance
fixation of the device 90 in the tissue. For example, the openings
94 in the flange 96 may receive suture (not shown) that secures the
fitting to tissue. In addition, the openings 94 in the flange 96
may be filled with a penetrable material, such as silicone, for
holding various devices or instruments, e.g., needles, forceps,
etc. For instance, a surgeon may use the material as a needle
holder while performing a suturing procedure.
[0088] The component 100 is positioned so as to be partially
disposed within the tissue T with a portion extending into the
blood source S. The distal end 22 of the conduit 18 is positioned
so as to extend slightly into the blood source S. The portion of
the component 100 disposed in the blood source S acts as a barrier
while allowing blood to enter the conduit 18. For instance, the end
of the conduit that is placed in the ventricle will be located near
tissue such as the chordae tendineae, papillary muscle or
myocardial tissue, thereby creating a risk of such tissue blocking
the flow of blood into the conduit. The struts 102 located in the
blood source S will prevent (or minimize) obstruction of the distal
end of the conduit 18 by such tissue, it being appreciated that the
length of the struts and the extent to which they extend into the
blood source may vary from that shown. In addition, the component
100 will prevent or minimize tissue being forced into the fitting
92 during placement of the fitting in the myocardium.
[0089] The embodiment of FIGS. 9-11 may rely on blood flow through
the conduit 18 to maintain the liner 28 fully (or substantially
fully) open within the interior of the fitting 92. However, it may
be desirable in some instances to positively secure the liner 28 to
the fitting 92 so as to ensure that the conduit 18 remains open
under varying conditions, e.g., pressure differences occurring
during the systolic and diastolic phases of the heart cycle. FIGS.
12 and 12A illustrate one embodiment in which the liner 28 is
positively secured to the fitting 92, the means for securing the
liner 28 comprising a layer 110 of silicone disposed along all or a
portion of the device 90.
[0090] The layer 100 of silicone fills the space between the
exterior of the liner 28 and the interior of the fitting 92, the
silicone acting as a biologically compatible adhesive that
maintains the liner against the wall of the fitting. The silicone
flows into the openings 94 in the fitting 92 which enhances
attachment of the liner 28. In the illustrated embodiment the
openings 94 have a flared end 112 opposite the liner 28. The ends
112 receive the silicone so that each opening 94 forms a rivet-like
plug of silicone that securely holds the liner 28 to the fitting
92. See FIG. 12A. Also, as shown in phantom in FIG. 12A, silicone
(or another material) may be placed on the exterior of the
rivet-like plug to provide a more secure connection.
[0091] In addition, the device 90 preferably includes another layer
114 of silicone disposed over the proximal end of the fitting 92 as
well as over a portion of the struts 102 of the component 100. The
layer 114 may be used to provide a smooth coating that covers the
edges of the struts 102 and the fitting 92 to avoid or minimize
trauma to tissue.
[0092] The device 90 may also be provided with means for preventing
the conduit 18 (and in particular the liner 28) from collapsing
during use. One suitable means is a strain relief element 116 that
surrounds the liner 28, as shown in FIG. 12. The strain relief
element 116 may be a helical wire, such as stainless steel or
nitinol, that is wrapped around the liner 28. The strain relief
element may extend over all or a portion of the length of the
conduit. If a layer of silicone is used as in the illustrated
embodiment, the element 116 may be bonded to or embedded in the
silicone.
[0093] Other means for preventing the liner 28 from collapsing
include placing an internal support member in the liner, such as a
stent (as shown in FIG. 6A), that maintains the conduit open.
Alternatively, the conduit, e.g., the liner 28, may be constructed
in a preformed shape that will resist kinking or collapsing; for
example, the conduit may be coated with a material that provides a
desired amount of rigidity, such as silicone, polyurethane, PTFE,
or other polymers. The coating is preferably on the exterior of the
liner 28 to maintain the ePTFE-blood interface. The liner 28 may be
provided with additional coatings selected to provide particular
qualities, such as heparin coatings. As another alternative, which
may be used in addition to or in lieu of providing the conduit with
a strain relief element to prevent kinking, the portion of the
conduit extending through the myocardium, such as the fitting 92 in
FIGS. 8-12, could be specifically formed to prevent kinking. For
instance, the fitting 92 could be L-shaped with a bend to prevent
kinking at the junction of the fitting and the remainder of the
conduit, the conduit including straight or tapered walls. Other
configurations may of course be used as well.
[0094] FIG. 13 is a perspective view of another embodiment of the
invention comprising a device (which may have the same construction
as the device 10 shown in FIG. 1) provided with a conduit 118
specifically configured to be placed in communication with a heart
chamber. The conduit 118 is loaded on the shaft assembly 14 and has
a distal end constructed as described above and a proximal end
provided with the device 90 shown in FIG. 9. The device 90 is
adapted to be placed in fluid communication with a source of blood
such as the left ventricle. The fitting 92 is placed in the tissue
of the myocardium so that the component 100 and the distal end of
the fitting 92 project slightly into the heart chamber, as shown in
FIG. 11.
[0095] FIG. 14 is a perspective view of still another embodiment of
the invention comprising a device (which also may have the same
construction as the device 10 shown in FIG. 1) provided with a
conduit 120. The conduit 120 is loaded on the shaft assembly 14 and
preferably has a distal end constructed as in the previous
embodiments. The conduit 120 also has a proximal end including a
device 90 (and component 100) that is adapted to be placed in fluid
communication with a heart chamber and is preferably constructed as
in the previous embodiments. It should be understood, though, that
this embodiment may be practiced with a conduit that is adapted to
be placed in communication with another blood source, such as the
aorta.
[0096] This embodiment of the invention allows a conduit to be
placed in fluid communication first with a source of blood and then
with a target vessel, or vice-versa. Placing the conduit in
communication with the blood source first may be useful to de-air
the conduit, i.e., force air from the conduit interior, prior to
securing the conduit to the target vessel. FIG. 14 shows one
construction wherein the conduit 120 has an opening 122 through
which the a portion of the shaft assembly 14 passes. The proximal
end of the conduit 120 including the device 90 may be positioned in
the myocardial tissue, for example, through an incision made in the
myocardium. The positive pressure in the heart chamber (especially
the high pressures present in the left ventricle during systole)
forces air through the conduit 120 and out the distal end adjacent
the sheath 42. The opening 122 may be substantially sealed against
the shaft assembly 14 of the device to force air toward the distal
end of the conduit 120.
[0097] The embodiment exemplified in FIG. 14 permits either end of
the conduit 120 to be placed first, which may be used to de-air the
conduit as described above. This feature of the invention also
provides flexibility so that in a given procedure the user has the
option to first secure the conduit to either the blood source or
the target vessel, which may be beneficial, for example, in a
multi-vessel bypass procedure where access to different areas of
the heart is obtained by temporarily moving or retracting all or a
portion of the heart.
[0098] The opening 122 in the conduit 120 is preferably formed to
allow its closure during the procedure. For instance, the conduit
120 could be clamped proximal to the opening 122 after the proximal
end of the conduit has been placed in communication with the blood
source and the conduit de-aired. The distal end of the conduit 120
could then be deployed in the target vessel and the shaft assembly
removed through the opening 122. Air would be forced out of the
conduit and the opening 122 then sealed by a patch formed of tissue
or synthetic vascular graft material such as ePTFE. The patch (not
shown) could by fixed to the conduit by various means, e.g.,
suture, clips, biologically compatible adhesives, etc.
Alternatively, the conduit 120 could include a collapsible,
foldable or crimpable member which is sealed closed after the shaft
assembly 14 has been removed from the conduit. It will be
recognized that an opening into the conduit could be formed at any
location along the length of the conduit and in any component
forming part of the conduit, for example, in the fitting 92 of
device 90.
[0099] The illustrated conduit 120 also is provided with means for
preventing the conduit from collapsing or kinking. The proximal end
122 of the conduit (or more of the conduit, if desired) is provided
with an internal support 124 to maintain the lumen of the conduit
120 open. The support 124 may be in the form of a self-expanding
stent formed of a suitable material such as nitinol, titanium or
tantalum. The support 124 preferably includes an articulated
portion 126 that supports a curved section of the conduit 120 (and
in particular the liner 128). The conduit is preferably rigid
enough to remain open while being somewhat flexible. The conduit
may be preformed to assume a desired orientation that provides an
optimum blood flow path or achieves particular flow
characteristics. Also, while the support 124 is shown disposed
within the conduit 120 it may instead surround the exterior of the
conduit.
[0100] The device of the invention may be sized and configured
differently from that specifically illustrated in the Figures. As
an example of a range of possible constructions, the device may be
relatively short with the shaft assembly substantially rigid for
use in an open-chest procedure. The device may be configured for
use in either a minimally invasive or endosvascular procedure,
wherein the actuators for controlling the device components are
located adjacent the proximal end of the device to allow remote
deployment of the conduit.
[0101] FIG. 15 is a perspective view of such a device constructed
according to another embodiment of the invention. The device 130 is
designed for use in a minimally invasive (e.g., laparoscopic,
thoracoscopic or endoscopic) procedure. The device 130 has a
similar construction to the device 10 described above and includes
a handle 132, a shaft assembly 134 and an actuator assembly 136.
The shaft assembly 134 supports a conduit 138 having a proximal end
140 and a distal end 142. A tubular access device 144 may be
provided so as to be moveable over the shaft assembly 134 and is
adapted to be passed through an opening in the patient's body. For
example, the opening could be a thoracotomy passing through the
chest wall for performing a thoracoscopic procedure (as shown in
FIG. 16), or it could be laparotomy passing into the abdominal
cavity to allow the chest cavity to be accessed through the
diaphragm. The device 144 may have a flange or other portion to
grip and manipulate the device with respect to the conduit 138
during use.
[0102] The conduit 138 is similar to the conduit 18 shown in FIG.
13 and comprises a vessel coupling in the form of a stent 146
coupled to a liner 148. A sheath 150 is disposed over the distal
end 148 of the conduit 138 and holds the end in a collapsed
orientation as explained above with respect to previous
embodiments. The shaft assembly 134 preferably includes a sheath
removal mechanism the body 152 of which is visible in FIG. 15. The
actuator assembly 136 includes a first actuator 154 for controlling
the sheath removal mechanism (which operates as described above),
and a second actuator 156 for controlling the position of the
sheath 150 with respect to the conduit 138. As in the previous
embodiment, the actuators 154, 156 are preferably arranged to
permit the conduit 138 to be deployed in the target vessel via a
one-handed operation, with the actuator 156 moving the sheath 150
to deploy the conduit and the actuator 154 removing the sheath 150
from the conduit 138.
[0103] FIG. 16 shows schematically one possible application for the
device 130 wherein a port P has been formed between a patient's
ribs to access the chest cavity and the heart (not shown). A trocar
sleeve or like structure 158 may be used to form the port P and one
or more retractors (not shown) may be used as well. The device 130
is shown positioned through the trocar sleeve 158 with a distal
portion of the shaft assembly 134 including the conduit 138
extending into the chest cavity. The actuator assembly is
preferably located at or near the proximal end of the device 130
which allows easy actuation to deploy the conduit 138 in the target
vessel. Additional ports P may be provided to introduce additional
instruments into the chest cavity. For example, the device 130
could be used to deploy the conduit 138 in the target vessel, the
device 130 removed, and one or more instruments passed through
other ports to place the conduit in communication with a source of
blood such as the aorta, a coronary vessel, or a heart chamber
containing blood. Alternatively, the conduit could be placed in
communication with the blood source prior to the target vessel.
[0104] The conduit may be placed in communication with the target
vessel in any of several manners according to the invention. In the
embodiment shown in FIGS. 6 and 6A, the lumen of the target vessel
may be partially or completely occluded by the conduit (and in
particular the liner) once the conduit section has expanded to its
final position. As a result, native blood flow from a proximal
source may be hindered or prevented from moving distally past the
attachment site between the conduit and the target vessel. In the
case of a coronary artery, the conduit could limit or block native
blood flow through the artery, i.e., blood flowing through the
artery from a proximal source, e.g., the aorta. Many patients
undergoing a CABG procedure will have some native blood flow in one
or more obstructed arteries. It therefore would be desirable to
place a conduit in fluid communication with the target vessel in a
manner that preserves such native blood flow in the target
vessel.
[0105] According to another embodiment of the invention a conduit
is placed in fluid communication with a target vessel while
preserving native blood flow through the target vessel. That is,
blood flowing through the target vessel prior to placing the
conduit is free to flow past the site of the attachment. One way of
achieving this is by constructing the conduit to include a portion
that is placed in the target vessel and allows flow past the
attachment site. Another way to preserve native flow is by forming
an opening in a solid wall of a conduit placed in the target vessel
lumen.
[0106] FIG. 17 shows a conduit 160 constructed in a manner that
preserves native blood flow in the target vessel. The conduit 160
comprises a stent 162 coupled to a liner 164 in a manner described
above with respect to previous embodiments. The stent 162 includes
a frame portion 166 with one or more members 168 that engage the
wall of the target vessel TV to secures the conduit 160 to the
vessel. The liner 164 preferably surrounds (either partially or
completely) the frame portion 166 but does not obstruct the lumen
of the target vessel TV. The conduit 160, and in particular the
stent 162 and frame portion 166, may be constructed and deployed in
a target vessel according to the teachings in the aforementioned
application Ser. No. 09/232,103, filed on Jan. 15, 1999 and
entitled "Methods and Devices for Forming Vascular Anastomoses,"
the entire subject matter of which has been incorporated herein by
reference.
[0107] An alternative conduit embodiment that preserves native flow
through the target vessel is designated by reference numeral 170 in
FIG. 18 and comprises a stent 172 coupled to a liner 174,
preferably in the manner described above with respect to previous
embodiments. The stent 172 includes a frame portion 176 that
includes a pair of frame members 178 which engage the wall of the
target vessel TV to secure the conduit 170 to the vessel. The liner
174 preferably surrounds the frame portion 176 as described in
connection with FIG. 17; however, for sake of clarity, the liner
174 is shown terminating at the junction of the conduit 170 and the
target vessel TV.
[0108] FIG. 19 is a flat pattern (two-dimensional) illustration of
a tube 180 that has been cut to form the stent 172 of FIG. 18. The
tube is cut to form first and second sections 182, 184
corresponding to the respective frame members 178. The sections
182, 184 have a diamond-pattern construction and are joined to the
body 186 by at least one, and preferably multiple attachment points
188. FIG. 19 shows the stent 172 in an expanded form but with the
frame portions 176 disposed along a first axis which, in the
illustrated embodiment, corresponds to the longitudinal axis of the
stent body 186. The frame members 178 preferably move to the
position shown in FIG. 18 in which they are disposed along a second
axis which is generally transverse to the first axis. In the
illustrated embodiment, the second axis is substantially
perpendicular to the first axis, although other configurations may
be used. Upon deployment of the conduit 170 in the target vessel
the frame members 178 preferably move along a curved path from the
first axis to the second axis.
[0109] Another alternative conduit embodiment that preserves native
flow through the target vessel is designated by reference numeral
190 in FIG. 20 and comprises a stent 192 coupled to a liner 194.
The stent 192 and liner 194 may be coupled in the manner described
above. The stent 192 includes a frame portion 196 which includes a
pair of frame members 198 for engaging the wall of the target
vessel TV, thereby securing the conduit 190 to the vessel as shown
in FIG. 20. As in the embodiment of FIG. 18, the liner 194
preferably surrounds the frame portion 176 but, for sake of
clarity, is shown ending at the junction of the conduit 170 and the
target vessel TV.
[0110] FIG. 20 is a flat pattern (two-dimensional) illustration of
a tube 200 that has been cut to form the stent 192 shown in FIG.
19. The tube is cut to form first and second sections 202, 204
corresponding to the respective frame members 198 which, in the
illustrated embodiment, have a zigzag configuration. The sections
202 and 204 are joined to the stent body 206 by at least one, and
preferably multiple attachment struts 208. FIG. 21 is similar to
FIG. 19 in that it shows the stent 192 in an expanded form but with
frame sections 198 disposed along the longitudinal axis of the
stent body 186 instead of transverse to the body, which is the
position the frame members 178 move to upon deployment of the
conduit 190 in a target vessel.
[0111] The conduits depicted in FIGS. 17-21, and in particular the
stents that form the vessel couplings of such conduits, may have
various configurations and may be formed according to the process
described above with respect to previous embodiments. That is, the
stents 162, 172 and 192 may be cut or formed from a suitable
material subjected to a procedure such as laser cutting, EDM
(electrical discharge machining), photochemical etching, etc. The
cut stent may be further processed or finished to remove burrs or
surface irregularities, for example, by acid etching,
electropolishing, or abrasive blasting. Next, the frame sections
that engage the wall of the target vessel are shape-set to their
expanded orientation. This may be done by placing the frame
sections in that orientation and applying sufficient heat to
produce a structure that will assume the desired configuration
above a certain temperature, e.g., 5.degree. below body
temperature. The stent may then be placed in its collapsed
orientation by cooling (e.g., with liquid nitrogen), coupled to a
liner and loaded onto a delivery device, and then deployed in a
target vessel.
[0112] The embodiments of the invention shown in FIGS. 17, 18 and
20 preserve native blood flow through the target vessel and have a
construction that does not cover a major portion of the inner or
posterior wall of the target vessel. As shown, the frame structure
that is placed in the target vessel contacts the inner wall of the
vessel to secure the conduit but leaves the majority of the vessel
wall uncovered. This allows blood flowing through the target vessel
to feed septal perforators (not shown but extending downward as
viewed in FIG. 17) so as to perfuse the myocardial tissue. This
feature thus prevents the myocardial tissue perfused by the septal
perforators from becoming ischemic due to the conduit located in
the target vessel. It should be appreciated that while it is
preferred to leave the majority of the vessel wall unexposed to
perfuse as many septal perforators as possible, the invention may
be practiced with a conduit that covers more or less of the vessel
wall than that shown.
[0113] The illustrated devices utilize a self-expanding stent and,
as such, the device is not provided with an expansion mechanism for
deploying the stent. It will be recognized, however, that either a
self-expanding stent or a stent expanded by suitable means, e.g., a
balloon or a non-inflatable expansion mechanism, may be used. For
example, the device may be constructed the same as or similar to
the device disclosed in application Ser. No. 09/232,102, filed on
Jan. 15, 1999, and entitled "Methods and Devices for Forming
Vascular Anastomoses," the entire subject matter of which has been
incorporated herein by reference. The device could be provided with
a separate inflation lumen for inflating the balloon to expand the
stent, or the design in the aforementioned application may be used
with seals such as O-rings or the like.
[0114] The invention also may use a conduit provided with a valve
or other means for controlling or regulating blood flow. A valve
could take the form, for example, of any of the valves disclosed in
application Ser. No. 09/023,492, filed on Feb. 13, 1998, and
entitled "Methods and Devices Providing Transmyocardial Blood Flow
to the Arterial Vascular System of the Heart," the entire subject
matter of which has been incorporated herein by reference.
[0115] Similarly, it will be appreciated that a conduit or vessel
coupling configured to preserve native blood flow in a target
vessel may be constructed differently than that shown in FIGS.
17-21. For example, the portion of the vessel coupling that is
disposed in the target vessel could take the form of a single
section of a coronary stent joined to the main body of the stent.
Further, if desired the portion of the vessel coupling that permits
native flow through the target vessel could control or meter the
flow. Other variations may be used as well.
[0116] It will be appreciated that the features of the various
preferred embodiments described herein may be used together or
separately, while the illustrated methods and devices may be
modified or combined in whole or in part. As an example, the
attachment formed between the conduit and the target vessel may be
suture-free while allowing or blocking native flow through the
target vessel; alternatively, the attachment may be formed to allow
native flow through the target vessel but be created using, in
whole or in part, conventional suturing techniques.
[0117] It should be appreciated that a device constructed according
to the invention could be operated with one or two hands (and by
one or more users), although a one-hand operable embodiment is
specifically illustrated. Also, the device of the invention may
include removable or detachable components, or could be constructed
as a one-piece instrument with no separable components. The device
may be formed as a disposable instrument, a reusable instrument
capable of being sterilized, or a combination of disposable and
reusable components.
[0118] Further, it will be understood that the embodiments may be
used in various types of procedures, for example, an open surgical
procedure including a median sternotomy, a minimally invasive
procedure utilizing one or more relatively small access openings or
ports, or an endovascular procedure using peripheral access sites.
Also, endoscopes or thoracoscopes may be used for visualization if
the procedure is performed through very small ports. The different
embodiments may be used in beating heart procedures, stopped-heart
procedures utilizing cardiopulmonary bypass (CPB), or procedures
during which the heart is intermittently stopped and started.
Finally, any suitable delivery device, instrument or catheter may
be used in conjunction with the invention.
[0119] It also will be recognized that the invention is not limited
to the illustrated applications, namely, placing a coronary vessel
in fluid communication with a source of blood. For example, the
invention may find application in treating peripheral arterial
disease in the distal abdominal aorta including the infrarenal
aorta and aortoiliac segment, aortofemoral, or carotid, and to
treat disease in the iliac and renal artery lesions.
[0120] The preferred embodiments of the invention are described
above in detail for the purpose of setting forth a complete
disclosure and for sake of explanation and clarity. It will be
readily understood that the scope of the invention defined by the
appended claims will encompass numerous changes and
modifications.
* * * * *