U.S. patent application number 11/594464 was filed with the patent office on 2007-03-08 for devices and methods for use in performing transmyocardial coronary bypass.
Invention is credited to Darin C. Gittings, Gilbert S. Laroya, Alan R. Rapacki, A. Adam Sharkawy.
Application Number | 20070055344 11/594464 |
Document ID | / |
Family ID | 21815415 |
Filed Date | 2007-03-08 |
United States Patent
Application |
20070055344 |
Kind Code |
A1 |
Gittings; Darin C. ; et
al. |
March 8, 2007 |
Devices and methods for use in performing transmyocardial coronary
bypass
Abstract
Devices and methods utilized in performing transmyocardial
coronary bypass include retractors used to engage and support
myocardial tissue, and mechanisms for supporting coronary vessels
so as to allow precise entry into a vessel lumen. In addition,
various conduits are provided having a configuration that permits
their positioning in a heart wall to place a coronary vessel in
communication with a heart chamber.
Inventors: |
Gittings; Darin C.;
(Sunnyvale, CA) ; Sharkawy; A. Adam; (Redwood
City, CA) ; Rapacki; Alan R.; (Redwood city, CA)
; Laroya; Gilbert S.; (Santa Clara, CA) |
Correspondence
Address: |
Katharine A. Jackson Huebsch;Medtronic, Inc.
710 Medtronic Parkway
Minneapolis
MN
55432
US
|
Family ID: |
21815415 |
Appl. No.: |
11/594464 |
Filed: |
November 8, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10011630 |
Oct 22, 2001 |
7137962 |
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11594464 |
Nov 8, 2006 |
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09023492 |
Feb 13, 1998 |
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10011630 |
Oct 22, 2001 |
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Current U.S.
Class: |
623/1.12 ; 604/8;
606/108; 606/198; 623/1.15; 623/1.36 |
Current CPC
Class: |
A61F 2250/0007 20130101;
A61F 2/82 20130101; A61F 2/94 20130101; A61B 2017/00247 20130101;
A61F 2210/009 20130101; A61F 2230/005 20130101; A61F 2/2493
20130101; A61B 2017/00252 20130101; A61F 2220/0016 20130101; A61B
2018/00392 20130101; A61F 2230/0091 20130101 |
Class at
Publication: |
623/001.12 ;
606/198; 623/001.36; 606/108; 604/008; 623/001.15 |
International
Class: |
A61F 2/84 20060101
A61F002/84; A61F 2/90 20060101 A61F002/90 |
Claims
1. A device for engaging tissue of a coronary vessel or heart wall
during a cardiovascular procedure, the device comprising: a first
member; a second member coupled to the first member so as to permit
relative movement of the first and second members; and a tissue
engaging mechanism coupled to the first and second members so as to
be movable between a first position and a second, actuated
position, the tissue engaging mechanism including at least one
tissue engaging member configured to engage body tissue when the
tissue engaging mechanism is in the second actuated position;
wherein relative movement of the fist and second members moves the
tissue engaging mechanism between the collapsed and expanded
orientations to selectively place the tissue engaging member in
engagement with body tissue.
2. The device of claim 1, wherein the first and second members are
first and second coaxial shafts with the tissue engaging mechanism
extending therebetween, and relative axial movement of the first
and second shafts moves the tissue engaging mechanism between a
collapsed orientation and an expanded orientation.
3. The device of claim 2, wherein each of the first and second
shafts has a proximal end and a distal end, and the tissue engaging
mechanism is disposed adjacent the distal ends of the shafts.
4. The device of claim 3, wherein at least one of the first and
second shafts has a portion configured to be passed through and
dilate an opening in tissue, wherein the tissue engaging mechanism
may be positioned adjacent tissue and then expanded to engage the
tissue.
5. The device of claim 1, further comprising an actuator coupled to
the first and second members for imparting relative movement
thereto in order to move the tissue engaging mechanism between the
collapsed and expanded orientations.
6. The device of claim 5, wherein the actuator comprises a handle
coupled to one of the first and second members for moving the one
member relative to the other member.
7. The device of claim 1, wherein the tissue engaging mechanism
includes a non-inflatable structure that is moved between the
collapsed and expanded orientations.
8. The device of claim 1, wherein the tissue engaging mechanism
includes a plurality of tissue engaging members each of which has
opposite ends coupled, respectively, to the first and second
members, wherein relative movement of the first and second members
imparts relative movement to the ends of the tissue engaging
members to move the tissue engaging mechanism between the collapsed
and expanded orientations.
9. The device of claim 1, wherein the tissue engaging mechanism
includes a balloon that is inflated by pressurized fluid to engage
the tissue.
10. The device of claim 1, wherein the tissue engaging mechanism
includes an expandable mesh that is moved between the collapsed and
expanded orientations in response to relative movement of the first
and second members.
11. The device of claim 1, wherein first and second tissue engaging
mechanisms are coupled to the first and second members so that each
mechanism is movable between a collapsed orientation and an
expanded orientation, the first and second tissue engaging
mechanisms being spaced from each other to permit body tissue to be
captured therebetween with the first and second tissue engaging
mechanisms engaging opposite surfaces of the body tissue.
12. A method for supporting heart tissue during a medical
procedure, the method comprising steps of: providing a tissue
support device having a tissue engaging mechanism configured to
assume an expanded, tissue supporting orientation; positioning the
tissue support device through the wall of a patient's heart and
locating the tissue engaging mechanism adjacent heart tissue; and
placing the tissue engaging mechanism in the expanded, tissue
supporting orientation in engagement with the heart tissue.
13. The method of claim 12, further comprising positioning a
conduit in the wall of the heart to place a coronary vessel in
communication with a heart chamber.
14. A device for supporting a wall of a vascular structure, the
device comprising: a support structure adapted to be removably
positioned in the lumen of a vascular structure, the support
structure comprising a plurality of support elements coupled
together so as to be movable relative to each other, wherein moving
the support elements relative to each other moves the support
structure from a collapsed orientation to an expanded orientation
in order to support a wall of a vascular structure; and wherein the
support elements are sized and configured for positioning in the
interior of the vascular structure such that when the support
structure is in the expanded orientation the support elements
engage the wall of the vascular structure to prevent the wall from
collapsing.
15. The device of claim 14, wherein the support elements comprise a
plurality of flexible struts each of which has a free end, wherein
the free ends of the struts are moved apart to place the support
structure in the expanded orientation.
16. The device of claim 15, further comprising a sheath coupled to
the flexible struts so that movement of the sheath relative to the
struts moves the free ends of the struts apart to place the support
structure in the expanded orientation.
17. The device of claim 14, wherein the support elements comprise a
plurality of flexible struts each of which has first and second
ends and a central portion between the ends, wherein the first ends
of the struts are fixed to each other and the second ends of the
struts are fixed to each other such that the central portions of
the struts move away from each other as the support structure moves
to the expanded orientation.
18. The device of claim 16, further comprising a sheath slidable
over the flexible struts, wherein the sheath is placed over at
least a portion of the struts to move the support structure to the
collapsed orientation and is removed from the said portion of the
struts to move the support structure in the expanded
orientation.
19. A device for supporting a vascular structure, the device
comprising: an introducer having a hollow interior; an elongated
support member configured to be generally coiled when in an
unbiased orientation and generally straight when in a biased
orientation; wherein the interior of the introducer is sized and
configured to receive the elongated support member and hold the
support member in the generally straight, biased orientation; and
wherein the elongated support member is moved from the straight,
biased orientation within the interior of the introducer to the
coiled, unbiased orientation upon entering the interior of the
vascular structure to support the vascular structure.
20. The device of claim 19, wherein the elongated support member is
a superelastic wire that is generally straight when in the biased
orientation and generally helical when in the unbiased
orientation.
21. The device of claim 20, wherein an end of the elongated support
member is sharpened for forming an opening in the wall of the
vascular structure to pass the support member into the interior of
the vascular structure.
22. The device of claim 19, wherein the elongated support member is
adapted to be removed from the vascular structure via the opening
through which the support member is passed into the vascular
structure.
23. A method for internally supporting a wall of a vascular
structure, the method comprising steps of: (a) positioning a
support within an interior of a vascular structure such that the
support contacts and supports a wall of the vascular structure; and
(b) introducing a medical device into the interior of the vascular
structure by passing the device through the wall of the vascular
structure and through the support.
24. The method of claim 23, wherein the support is an elongated
member configured in a generally straight orientation prior to
being positioned in the interior of the vascular structure and
assumes a generally coiled orientation once positioned in the
interior of the vascular structure, the medical device being
introduced between coils of the support into the vascular
structure.
25. The method of claim 23, wherein the support is movable between
collapsed and expanded orientations, and step (a) is carried out by
introducing the support into the vascular structure in said
collapsed orientation and then moving the support to said expanded
orientation.
26. The method of claim 23, wherein the support comprises a sleeve
having at least one opening formed therein through which the
medical device is introduced.
27. The method of claim 23, wherein the vascular structure is a
coronary artery and the medical device is a conduit delivery device
that is passed through the coronary artery to position a conduit in
the wall of the heart to communicate the coronary artery with a
heart chamber.
28. The method of claim 23, further comprising the step of removing
the medical device and the support from the vascular structure.
29. A method for supporting a wall of a vascular structure at an
area adjacent an incision in the wall of the vascular structure,
the method comprising steps of: inserting a support through the
incision in the wall of the vascular structure while the support is
in a low profile orientation; positioning at least a portion of the
support within the interior of the vascular structure; and moving
the support from the low profile orientation into an expanded
orientation so as to contact and support the wall of the vascular
structure.
30. The method of claim 29, further comprising introducing a
medical device into the interior of the vascular structure by
passing the device through the support.
31. The method of claim 30, wherein the vascular structure is a
coronary artery and the medical device is a conduit delivery device
that is passed through the coronary artery to position a conduit in
the wall of the heart to communicate the coronary artery with a
heart chamber.
32. A device for stabilizing an area of a patient's heart adjacent
a coronary vessel, the device comprising: a base configured to be
positioned adjacent a coronary vessel of a patient's heart, the
base having at least one opening for accessing the coronary vessel;
at least one tissue engaging element coupled to the base so as to
be movable with respect to the base, the tissue engaging element
having a portion configured to securely engage the wall of a
patient's heart in order to stabilize the wall of the heart upon
moving the tissue engaging element with respect to the base; and an
actuator for imparting relative movement to the base and the tissue
engaging element in order to stabilize the heart while accessing
the coronary vessel through the opening in the base.
33. The device of claim 32, wherein the base has a single opening
for accessing the coronary vessel and a plurality of tissue
engaging elements are coupled to the base.
34. The device of claim 33, wherein the tissue engaging elements
comprise legs each of which has one end pivotally attached to the
base and another end provided with a member configured to at least
partially penetrate the wall of the heart.
35. The device of claim 34, wherein the base has a plurality of
recesses each of which pivotally mounts the one end of one of the
legs, each recess having a cam surface that moves the leg with
respect to the base when the base is rotated.
36. The device of claim 32, wherein the tissue engaging elements
include a sharpened end configured to partially penetrate the wall
of the heart.
37. The device of claim 36, wherein each tissue engaging element
has an end provided with an expandable member, the expandable
member configured to be passed through the wall of the heart to a
location adjacent a surface of the wall opposite the coronary
vessel and then expanded to engage said surface of the wall.
38. A conduit for placing a coronary vessel of a patient's heart in
communication with a heart chamber, the conduit comprising: a
tubular element including first and second portions having
different cross-sectional sizes, the tubular element having a bore
defining a blood flow path; wherein the cross-section of the first
portion of the tubular element is larger than the cross-section of
the second portion of the tubular element such that the tubular
element is generally funnel-shaped; and wherein the first and
second portions of the tubular element are generally aligned and
the bore defines a generally straight blood flow path.
39. A conduit for communicating a chamber of a patient's heart with
a coronary vessel, the conduit comprising: an expandable stent
including first and second ends and a length defined between the
ends, the length of the stent including first and second portions
having different cross-sectional sizes when the stent is expanded;
wherein each of the first and second portions of the stent includes
strut members disposed along a first direction when the stent is
unexpanded and along a second direction when the stent is expanded,
the second direction being transverse to the first direction; and
wherein the strut members of the first portion are longer than the
strut members of the second portion and the stent is generally
funnel-shaped when expanded.
40. A device for use in a coronary vessel of a patient's heart, the
device comprising: an expandable stent including a bore defining a
blood flow path and first and second portions, the first and second
portions having different cross-sectional sizes when the stent is
expanded; wherein the first portion has a larger cross-sectional
dimension than the second portion when the stent is expanded such
that the stent is generally funnel-shaped when expanded; and
wherein the first and second portions of the stent are constructed
to provide the stent with maximum radial strength when
expanded.
41. The device of claim 40, wherein the stent is configured to be
positioned and retained in a heart wall to place a coronary vessel
in communication with a heart chamber.
42. The device of claim 40, wherein the stent has a plurality of
openings along the length of the stent through which blood may
flow.
43. (canceled)
44. A conduit for placing a coronary vessel of a patient's heart in
communication with a heart chamber, the conduit comprising: a
tubular element configured to positioned in the wall of a patient's
heart, the tubular element including first and second ends and a
bore defining a blood flow path; and a vessel supporting mechanism
carried by the tubular element, the vessel supporting mechanism
being positioned on the conduit so as to contact and support the
wall of a coronary vessel when the conduit is positioned in the
heart wall.
45. The conduit of claim 44, wherein the tubular element is a
rigid, solid walled structure.
46. The conduit of claim 44, wherein the tubular element is an
expandable stent including a plurality of struts, and the vessel
supporting mechanism comprises some of the struts.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 09/023,492, filed 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
application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to treating heart disease, and more
particularly systems, devices and methods for reestablishing or
improving blood flow to the myocardium.
[0004] 2. Description of 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 the 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 intracoronary
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, which is accomplished, for example, by
enlarging the blood flow lumen of the artery or by 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] Technological and procedural advances have improved the
results obtained by the medical procedures now used to treat heart
disease, and in particular coronary artery disease. There is,
however, still much room for improvement. For that reason there
remains a need in the art for new and improved systems, devices and
methods for treating heart disease such as arteriosclerosis.
SUMMARY OF THE INVENTION
[0008] In one embodiment, the invention provides a device and
method for engaging tissue of a coronary vessel or heart wall
during a cardiovascular procedure. A device constructed according
to this embodiment includes first and second members coupled
together so as to permit relative movement. A tissue engaging
mechanism is coupled to the first and second members and moves
between first and second positions. In the preferred embodiment,
the first and second positions are collapsed and expanded
orientations. The tissue engaging mechanism includes at least one
tissue engaging member that contacts engage body tissue when in the
expanded orientation.
[0009] A method carried out according to this embodiment includes
steps of providing a tissue support device having a tissue engaging
mechanism configured to assume an expanded, tissue supporting
orientation, positioning the tissue support device through the wall
of a patient's heart and locating the tissue engaging mechanism
adjacent tissue, and placing the tissue engaging mechanism in the
expanded, tissue supporting orientation in engagement with the
tissue.
[0010] In another embodiment, the invention provides a device and
method for supporting a wall of a vascular structure in order to
access the lumen of the vascular structure. A device constructed
according to this embodiment includes a support structure adapted
to be positioned in the lumen of a vascular structure, the support
structure comprising a plurality of support elements coupled
together so as to be movable relative to each other. The support
elements move relative to each other to move the support structure
from a collapsed orientation to an expanded orientation in order to
support a wall of a vascular structure, and are sized and
configured so that when the support structure is in the expanded
orientation the support elements engage the wall of the vascular
structure to prevent the wall from collapsing.
[0011] Another device constructed according to this embodiment
includes an introducer having a hollow interior and an elongated
support member configured to be generally coiled when in an
unbiased orientation and generally straight when in a biased
orientation. The interior of the introducer is sized and configured
to receive the elongated support member and hold the support member
in the generally straight, biased orientation. The elongated
support member is moved from the straight, biased orientation
within the interior of the introducer to the coiled, unbiased
orientation upon entering the interior of the vascular structure to
support the vascular structure.
[0012] A method carried out according to this embodiment includes
steps of positioning a support within an interior of a vascular
structure such that the support contacts and supports a wall of the
vascular structure, and introducing a medical device into the
interior of the vascular structure by passing the device through
the wall of the vascular structure and through the support.
[0013] In another embodiment, the invention provides a device and
method for stabilizing an area of a patient's heart adjacent a
coronary vessel. A device constructed according to this embodiment
includes a base configured to be positioned adjacent a coronary
vessel of a patient's heart, the base having at least one opening
for accessing the coronary vessel. At least one tissue engaging
element is coupled to the base so as to be movable with respect to
the base, the tissue engaging element having a portion configured
to securely engage the wall of a patient's heart in order to
stabilize the wall of the heart upon moving the tissue engaging
element with respect to the base. An actuator is provided for
imparting relative movement to the base and the tissue engaging
element in order to stabilize the heart while accessing the
coronary vessel through the opening in the base.
[0014] In yet another embodiment, the invention provides a conduit
for placing a coronary vessel of a patient's heart in communication
with a heart chamber. The conduit is in the form of a tubular
element including first and second portions having different
cross-sectional sizes and a bore defining a blood flow path. The
cross-section of the first portion of the tubular element is larger
than the cross-section of the second portion such that the tubular
element is generally funnel-shaped, and the first and second
portions of the tubular element are generally aligned so that the
bore defines a generally straight blood flow path.
[0015] In still another embodiment, the invention provides a
conduit for communicating a chamber of a patient's heart with a
coronary vessel. The conduit is in the form of an expandable stent
including first and second portions having different
cross-sectional sizes when the stent is expanded. Each of the first
and second portions of the stent includes strut members disposed
along a first direction when the stent is unexpanded and along a
second direction when the stent is expanded, the second direction
being transverse to the first direction. The strut members of the
first portion are longer than the strut members of the second
portion so that the stent is generally funnel-shaped when
expanded.
[0016] In another embodiment, the invention provides a conduit is
in the form of an expandable tubular element having first and
second portions with different cross-sectional sizes. This tubular
element is preferably a coronary stent constructed so that the
first and second portions are disposed in an orientation that
provides the stent with maximum radial strength when expanded.
[0017] In a final embodiment, the invention provides a conduit for
placing a coronary vessel in communication with a heart chamber,
the conduit including a vessel support mechanism configured to
contact and support the vessel wall when the conduit is positioned
in the heart wall.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention will be better understood from the following
detailed description of preferred embodiments thereof, taken in
conjunction with the accompanying drawing figures, wherein:
[0019] FIG. 1 is a schematic view of a patient prepared to undergo
a cardiovascular surgical procedure, the patient's heart being
exposed via a retractor positioned in a thoracotomy formed in the
patient's chest;
[0020] FIG. 2 is a perspective view of the heart shown in FIG. 1,
wherein a portion of the heart wall is broken away for clarity;
[0021] FIG. 2A is an enlarged view of a portion of FIG. 2;
[0022] FIGS. 3A-3B are perspective views showing a tissue engaging
device constructed according to one embodiment of the invention,
the device being shown in collapsed and expanded orientations,
respectively;
[0023] FIGS. 4A-4B are elevation views, in section, illustrating
one preferred construction of a tissue engaging device according to
the embodiment of FIGS. 3A-3B, wherein the device is shown being
used to engage the heart wall shown in FIGS. 2-2A;
[0024] FIGS. 5A-5B are elevation views, in section, illustrating
another preferred construction of a tissue engaging device
according to the embodiment of FIGS. 3A-3B, wherein the device is
shown being used to engage the heart wall shown in FIGS. 2-2A;
[0025] FIGS. 6A-6C are elevation views, in section, sequentially
illustrating a vessel support device constructed according to
another embodiment of the invention being used to support the wall
of a vascular structure;
[0026] FIG. 7 is a perspective view of a vessel support device
constructed according to an alternative embodiment of the
invention, the device being shown positioned in the interior of a
vascular structure;
[0027] FIGS. 8A-8B are elevation views, in section, sequentially
illustrating the device shown in FIG. 7 being used to support a
coronary artery of the heart shown in FIGS. 2-2A;
[0028] FIG. 9 is a perspective view of a vessel support device
constructed according to another alternative embodiment of the
invention, the device being shown positioned in the interior of a
vascular structure;
[0029] FIGS. 10A-10B are elevation views, in section, sequentially
illustrating the device shown in FIG. 9 being used to support a
coronary artery of the heart shown in FIGS. 2-2A;
[0030] FIGS. 11A-11B are plan views of a tissue engaging device
constructed according to another embodiment of the invention,
wherein the device is shown engaging the wall of the heart shown in
FIGS. 2-2A in non-retracting and retracting orientations,
respectively;
[0031] FIGS. 12A-12B are elevation views, in section, taken along
lines A-A in FIGS. 1A-1B;
[0032] FIG. 13 is an elevation view, in section, of an alternative
tissue engaging device constructed according to the embodiment
shown in FIGS. 12A-12B;
[0033] FIGS. 14A-14B are elevation views of a tapered balloon
forming part of another embodiment of the invention, wherein the
balloon is shown in its collapsed and expanded orientations,
respectively;
[0034] FIGS. 15A-15B are elevation views of an expandable conduit
mounted on the tapered balloon shown in FIGS. 14A-14B, the conduit
being shown in its collapsed and expanded orientations,
respectively;
[0035] FIG. 16 is an elevation view, in section, of a portion of a
heart wall and coronary vessel in which the conduit shown in FIG.
15A-15B has been positioned;
[0036] FIGS. 17A-17B are elevation views showing a conduit
constructed according to still another embodiment of the invention,
wherein the conduit has a cross-sectional size that varies over its
length;
[0037] FIG. 18 is a perspective view of another embodiment of the
invention providing a conduit for placing a coronary vessel in
communication with a heart chamber while internally supporting the
interior of the vessel;
[0038] FIGS. 19A-19C are schematic representations of a preferred
application for the conduit shown in FIG. 18;
[0039] FIG. 20 is a perspective view of an alternative embodiment
of a conduit for placing a coronary vessel in communication with a
heart chamber while internally supporting the interior of the
vessel;
[0040] FIG. 21 is a perspective view of another alternative
embodiment of a conduit for placing a coronary vessel in
communication with a heart chamber while internally supporting the
interior of the vessel; and
[0041] FIG. 22 is a perspective view of yet another alternative
embodiment of a conduit for placing a coronary vessel in
communication with a heart chamber while internally supporting the
interior of the vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] FIG. 1 schematically depicts a patient who has been prepared
to undergo a cardiovascular surgical procedure. A thoracotomy T
formed in the patient's chest by making an incision between two
ribs (not shown) provides access to the thoracic cavity. A
retractor, such as the rib retractor R shown in FIG. 1, may be used
to spread the ribs and increase access to the heart H and great
vessels. The retractor is preferably of a type that in addition to
spreading the sides of the incision along a first plane, also
raises one side of the incision with respect to the other side to
increase the working space around the heart. Any suitable retractor
may be used, for example, one of the commercially available rib
retractors currently used in minimally invasive cardiac surgery. As
shown in FIG. 1, the retractor R provides considerable access to
the surfaces of the heart H and great vessels including the aorta
A. The left side of the heart as well as the left coronary artery
LCA is easily accessible via the thoracotomy T (FIG. 1).
[0043] FIG. 2 is an anterior view of a heart 10 showing the left
ventricle 12, right ventricle 14, right atrium 16, aorta 18,
pulmonary trunk 20 and pulmonary veins 22. In FIG. 2 the heart 10
is in diastole, or the relaxed phase of the heart cycle, so the
aortic valve 24 is shown closed. The left coronary artery 26,
including the circumflex branch 28 and the left anterior descending
branch (LAD) 30, is visible in this view, as is the right coronary
artery 32. The coronary arteries 26, 28, 30, 32 run along the heart
wall 34 and deliver oxygenated blood to the tissue comprising the
heart wall (epicardium, myocardium and endocardium) while the
coronary veins run alongside the arteries and return blood to the
coronary sinus (not shown).
[0044] A blockage or occlusion 36 is shown in the LAD 30 and
results in partial or complete obstruction of the artery lumen 42,
a condition often referred to as narrowing of the arteries. This
results in inadequate or no blood flow to the heart wall tissue fed
by the portion of the LAD 30 that is downstream of the occlusion
36. FIGS. 2-2A show a portion of the heart wall 34 disposed between
the left ventricle 12 and the LAD 30, as well as the inner and
outer walls 38, 40 of the LAD 30. The devices and methods of the
different embodiments of the invention are illustrated and
described in connection with their use on the portion of the heart
10 shown in FIG. 2A. It will be understood, however, that such
description is for explanatory purposes and exemplifies only one
application for the invention.
[0045] FIGS. 3A-3B illustrate a first embodiment of the invention
that provides a device and method for engaging tissue of a coronary
vessel or heart wall during a cardiovascular procedure. A preferred
device is indicated generally by the reference numeral 100 and
includes first and second relatively movable members and a tissue
engaging mechanism coupled to the members. In the illustrated
embodiment the members comprise first and second coaxial shafts
102, 104 coupled to a tissue engaging mechanism 106. Specifically,
the tissue engaging mechanism 106 is coupled to the shafts 102, 104
so that relative movement imparted to the shafts results in the
mechanism 106 moving between a collapsed orientation (FIG. 3A) and
an expanded, tissue engaging orientation (FIG. 3B).
[0046] The first shaft 102 has a distal end 108 which is secured to
a distal end 110 of the shaft 104. The tissue engaging mechanism
106 is disposed adjacent the distal ends 108, 110 of the shafts
102, 104 and comprises one or more tissue engaging members 112
which move radially outward when the mechanism is in the expanded
orientation. Each tissue engaging member 112 has one end 114 fixed
to the distal end 108 of shaft 102 at 116, and another end 118
fixed to the shaft 104 at 120. FIG. 3A shows the tissue engaging
mechanism 106 in its collapsed orientation with the members 112
generally straight. FIG. 3B shows the tissue engaging mechanism 106
in its expanded orientation in which the members 112 extend outward
in a radial direction. The components of the device 100 may be
formed of any suitable material.
[0047] The orientation of the tissue engaging mechanism 106 is
controlled by imparting relative movement to the shafts 102, 104.
The device 100 is preferably introduced into a coronary vessel or
heart wall with the tissue engaging mechanism 106 in the low
profile orientation shown in FIG. 3A. The device 100 may have a
sharpened tip as shown, or it may have a dilating portion that
dilates a previously-formed incision. Once passed through the
tissue to a desired position, the tissue engaging mechanism 106 is
moved to the expanded orientation shown in FIG. 3B in order to
engage tissue. This may be achieved by moving the inner shaft 102
in the direction of the arrows with respect to the outer shaft 104,
which moves the ends 114, 118 of the tissue engaging members 112
toward each other to expand the mechanism 106. In the orientation
shown in FIG. 3B, the device 100 may be used to perform any of
various functions, for example, to support, retract or stabilize
tissue during a cardiovascular procedure.
[0048] FIGS. 4A-4B show one application of the device 100, namely,
to engage the tissue of the wall of a patient's heart. As shown in
FIG. 4A, the device 100 is inserted through a coronary vessel such
as LAD 30 and the heart wall 34 with the tissue engaging mechanism
106 in its collapsed orientation. Upon moving the tissue engaging
mechanism 106 out of the heart wall 34 and into a heart chamber
such as left ventricle 12, the shafts 102, 104 are moved with
respect to each other to expand the tissue engaging mechanism 106
to the position shown in FIG. 4A. The expanded tissue engaging
mechanism 106 may then be used to engage and support the heart wall
34 to facilitate carrying out a cardiovascular procedure, for
example, placing a conduit (not shown) in the heart wall to place
the coronary vessel in communication with the heart chamber, or
forming a channel in the heart wall to place the coronary vessel in
communication with the heart chamber.
[0049] FIGS. 5A-5B show another application of the device 100,
namely, to engage the tissue of the wall of a coronary vessel. As
above, the device 100 is introduced with the tissue engaging
mechanism 106 in its collapsed orientation, the device being passed
through the heart wall 34 and then the inner wall 38 of the LAD 30.
Once the tissue engaging mechanism 106 has moved into the lumen 42
of the LAD 30, the shafts 102, 104 are moved with respect to each
other to expand the tissue engaging mechanism 106 to the
orientation shown in FIG. 5A. The tissue engaging mechanism 106 may
then be used to engage and support the wall 38 of the LAD and the
heart wall 34 to facilitate carrying out a cardiovascular
procedure. Examples of such procedures include placing a conduit
(not shown) in the heart wall to place the coronary vessel in
communication with the heart chamber, and forming a channel in the
heart wall to place the coronary vessel in communication with the
heart chamber.
[0050] As shown in FIGS. 3A-3B, the device 100 may have a second
tissue engaging mechanism 106A so that a body of tissue may be
sandwiched between the two mechanisms 106, 106A for added
stability.
[0051] FIGS. 6A-6C depict another embodiment of the invention that
provides a device and method for supporting a wall of a vascular
structure in order to access the lumen of the vascular structure.
One device constructed according to this embodiment is designated
generally by the reference numeral 130 and includes an elongated
support member 132 and an introducer 134. The introducer has a bore
136 that is configured to receive the support member 132, as shown
in FIG. 6A and preferably has a small diameter in order to minimize
the size of the opening in the vascular structure, which in the
illustrated embodiment is a coronary vessel and, in particular, LAD
30.
[0052] The elongated support member 132 is preferably constructed
so as to expand when in an unbiased orientation, i.e., when it is
not constrained by the introducer 134. In the preferred embodiment,
the support member 132 is constructed to assume a coiled shape when
in the unbiased orientation, for example, the helical configuration
shown in FIG. 6B. When disposed in the introducer 134, however, the
support member 132 is in a biased orientation and assumes a
generally straight shape within the bore 136 of the introducer.
[0053] An exemplary application for the device 130 will be
explained with reference to FIGS. 6A-6C. Initially, as shown in
FIG. 6A, an end 138 of the introducer 134 is positioned against the
exterior of the wall 40 of the LAD with the elongated support
member 132 disposed within the introducer 134. Alternatively, as
shown in phantom in FIG. 6A, the end 138 of the introducer 134 may
be passed through the wall 40 into the lumen 42 of the LAD 30. If
used in this manner, the support member 132 does not need to pierce
the tissue of the vascular structure; if used as shown in solid
lines in FIG. 6A, an end 140 of the support member 132 is
preferably sharpened to pierce through the wall of the vascular
structure.
[0054] The elongated support member 132 is fed through the
introducer 134 into the lumen 42 of the LAD 30. The support member
132 forms a coil 142 as it exits the introducer 134, as shown in
FIG. 6B. The support member is constructed so that the coil 142 has
a size that contacts and distends slightly the LAD 30, thereby
providing support to the LAD to allow precise entry into the lumen
42 of the LAD. A medical device may then be inserted through the
wall of the vascular structure and the support member. For example,
FIG. 6C shows a medical device 144 inserted through the wall 40 of
the LAD 30 and through the coil 142. The device 144 is then removed
upon completing the procedure; the elongated support member 132 may
then be removed from the LAD 30 by retracting the member back into
the bore 136 of the introducer 134.
[0055] The elongated support member 132 may be formed of any
suitable material having sufficient memory to assume an expanded
configuration when unbiased, such as spring wire or nitinol. As an
example, the support member 132 could be formed of a length of
nitinol wire having an approximate diameter of 0.007 inch that has
been wrapped on a suitable mandrel (not shown), such as a stainless
steel rod having an approximate diameter of 0.060 inch. The mandrel
and wire are then heated to set the shape in the wire which, per
se, is known in the art. The mandrel may have two apertures that
receive the ends of the nitinol wire and a relief section that
causes the end 140 of the support member to roll inward toward the
interior of the coil 142, which minimizes the risk of the end 140
damaging tissue.
[0056] It will be recognized that the device 130 may be used to
support a vascular structure independently of carrying out a
medical procedure. As an example, the device 130 could be used to
introduce the support member 132 into a coronary artery in order to
stent the artery, the coil 142 remaining in place in the same
manner as a conventional coronary stent. In this embodiment, it may
be desirable to form the other end 146 of the support member 132 so
that it too moves toward the interior of the coil 142 upon exiting
the introducer 134 to avoid tissue damage.
[0057] FIGS. 7 and 8A-8B depict an alternative embodiment of a
device and method for supporting a wall of a vascular structure in
order to access the lumen of the vascular structure. The device is
indicated generally by the reference numeral 160 and is configured
to be placed in a collapsed orientation for introduction into a
vascular structure and then expanded to contact and support the
wall of the structure. The device 160 comprises a support structure
162 removably retained in an introducer 164. The illustrated
support structure 162 comprises a plurality of struts 166 that form
a basket-like member when moved out of the introducer 164. For
example, the struts 166 may be in the form of resilient wires that
move away from each other as the support structure 162 exits the
introducer 164, the wires extending between proximal and distal
portions 168, 170 of the support structure. The introducer 164 may
be a sheath or sleeve sized and configured to at least partially
surround the support structure 162 and hold the struts 166
together. The respective components may be formed of suitable
materials, such as spring wire and a polymer sleeve.
[0058] FIG. 7 shows one preferred use of the device 160 wherein the
device is inserted through an opening in a vascular structure, such
as incision 44 in LAD 30. It will be noted, though, that the device
may be passed through a peripheral vessel to a desired location
within a vascular structure, and then expanded within the vascular
structure by moving the support structure out of the introducer. As
shown in FIG. 8A, the device is passed through the incision 44 and
into the lumen 42 of the LAD 30. The introducer 164 is then
retracted over the proximal portion 168 of the support structure
which results in the struts 166 moving away from each other to
contact and support the wall of LAD 30. As explained above with
respect to the previous embodiment, various medical devices may
then be introduced through the wall of the vascular structure and
through the support structure 162. Upon completion of the
procedure, the introducer 164 is slid back over the struts 166 to
collapse the support structure 162, which allows the device 160 to
be removed through the incision 44.
[0059] FIGS. 9 and 10A-10B illustrate another alternative
embodiment of a device and method for supporting a wall of a
vascular structure in order to access the lumen of the vascular
structure. The device has a construction somewhat similar to the
device 160 in FIGS. 7 and 8A-8B. The device is indicated generally
by the reference numeral 180 in FIG. 9 and is configured to be
placed in a collapsed orientation for introduction into a vascular
structure and then expanded to contact and support the wall of the
structure. The device 180 comprises a support structure 182
removably retained in an introducer 184. The illustrated support
structure 182 includes a plurality of struts 186 which may be in
the form of resilient wires that move away from each other as the
support structure exits the introducer 184. The struts 186 may be
joined at their proximal ends 188 and preferably have distal ends
190 with a non-traumatic configuration to prevent tissue damage. As
in the previous embodiment, the introducer 164 may be a sheath or
sleeve sized and configured to at least partially surround the
support structure 162 to hold the struts 186 together. The
materials used in the embodiment of FIG. 7 may be used in this
embodiment.
[0060] As shown in FIG. 10A, the device 180 is passed through the
incision 44 and into the lumen 42 of the LAD 30, and the introducer
184 is then retracted to allow the struts 186 to move away from
each other. This results in the support structure 182 assuming the
expanded orientation shown in Fig. 10B wherein the struts 186
contact and support the wall of LAD 30. As with the previous
embodiments, various medical devices may then be introduced through
the wall of the vascular structure and through the support
structure 162.
[0061] It will be appreciated that the vascular support devices and
methods illustrated in the drawings are only preferred embodiments
of the invention. This aspect of the invention encompasses
supporting the wall of a vascular structure in order to allow
precise entry into the lumen, which may be relatively difficult if
the wall of the vascular structure is collapsed. Accordingly, many
variations of the disclosed devices and methods will be apparent to
those skilled in the art. For example, an alternative design
utilizes an expandable support that may be in the form of a stent
having one or more openings to allow passage of medical devices
into the lumen of the vascular structure. The stent could have any
desired coverage area with openings provided between adjacent stent
elements or formed by removing portions of the stent elements.
[0062] Another alternative design comprises a device in the form of
a member configured to rest on the exterior of the vascular
structure to provide access into the lumen of the structure. The
device may have a distal portion shaped somewhat complementarily to
the vascular structure to closely engage same. For example, the
distal portion could include a concave recess that receives the
vascular structure when the device is rested on surrounding tissue.
The device preferably has a bore that opens into the recess so that
a medical device inserted into the bore passes through the wall of
the vascular structure.
[0063] Additionally, while the vessel support devices are shown
introduced into the vessel through the wall close to or at the area
of the vessel that is supported. The support devices could be
positioned in an alternative manner, for example, by passing the
device through the artery lumen from a location downstream of the
area that is supported.
[0064] FIGS. 11A-11B and 12A-12B show another embodiment of the
invention that provides devices and methods for stabilizing an area
of a patient's heart adjacent a coronary vessel. The illustrated
device is indicated generally by the reference numeral 200 and
comprises a base 202 configured to be positioned adjacent a
coronary vessel of a patient's heart. The base 202 has at least one
opening 204 which provides access to the coronary vessel, which, in
the illustrated embodiment, is the LAD 30. The device 200 also
includes at least one, and preferably a plurality, of tissue
engaging elements 206 coupled to the base 202 so as to be movable
with respect thereto. Each tissue engaging element 206 has an end
208 configured to securely engage the tissue of a patient's heart
in order to stabilize the heart, and an end 210 coupled to the base
202. Each end 210 is pivotally attached to the base 202 by a pivot
pin 212.
[0065] The base 202 has a plurality of recesses 214 each of which
mounts an end 210 of a tissue engaging element 206. Each of the
recesses 214 has a cam surface 216 that engages the end 210 of a
tissue engaging element 206 upon actuating the device in order to
retract the cardiac tissue and stabilize the heart. To that end,
the device 200 has an actuator to drive the tissue engaging
elements 206 and retract tissue. The actuator may comprise rotating
the base 202 so as to drive the cam surfaces 216 of recesses 214
against the ends 210 of the tissue engaging elements 206. FIG. 11A
shows the device 200 before actuation; FIG. 11B shows the device
after the base 202 has been rotated. Each tissue engaging element
206 is preferably biased to the position of FIGS. 11 A and 12A by
suitable means, such as tension springs extending between the base
202 and the tissue engaging elements 206. The components of the
device 200 may be made from any suitable materials; for example,
the base may comprise a polymer while the elements 206 are
metal.
[0066] FIGS. 11A-11B and 12A-12B show one possible application for
the device 200, retracting the wall of a heart adjacent a coronary
vessel to stabilize vessel. The device 200 is positioned on the
heart wall 34 so that the opening 204 overlies the LAD 30. The ends
208 of the tissue engaging elements 206 are engaged with the tissue
of the heart wall 34 by any suitable means. As shown in FIGS.
12A-12B, the ends 208 may simply have sharp tips which are passed
into the tissue to engage the elements with the heart wall.
[0067] Alternatively, as shown in FIG. 13, the ends 208 of the
tissue engaging elements 206 may have a mechanism for more securely
engaging the tissue, such as expandable members 218. The expandable
members 218 may be constructed as described above with respect to
the embodiment of FIGS. 3A-3B, thereby allowing the ends 208 to be
collapsed, for passage through the heart wall and then expanded
once through the wall in order to positively secure the device 200
to the tissue. The members 218 may be expanded by moving one shaft
relative to another as described above.
[0068] Once the ends of the tissue engaging elements have been
secured to the tissue, as shown in FIGS. 11A and 12A, the base 202
is rotated as described above,. which drives the tissue engaging
elements relative to the base and the tissue. This action tensions
the tissue of the heart wall 34 to retract the wall and stabilize
the heart in the area of the coronary vessel, as shown in FIGS. 11B
and 12B. As a result, the coronary vessel, which is the LAD 30 in
the Figures, is stabilized so that subsequent procedures may be
carried out on a relatively stable site. As an example, the device
200 may be used to stabilize the heart while passing a conduit
delivery device through the vessel and the heart wall in order to
place the vessel in communication with a heart chamber.
[0069] According to another embodiment of the invention, a conduit
is provided for placing a coronary vessel of a patient's heart in
communication with a heart chamber. The conduit comprises a tubular
element including first and second portions having different
cross-sectional sizes, and a bore defining a blood flow path. The
cross-section of the first portion of the tubular element is larger
than the cross-section of the second portion of the tubular
element. In one preferred embodiment the different cross-sectional
configurations are selected to produce a tubular element that is
generally funnel-shaped.
[0070] According to one aspect of this embodiment, the first and
second portions of the tubular element are generally aligned and
the bore defines a generally straight blood flow path. According to
another aspect of this embodiment, the tubular element is an
expandable stent including a bore defining a blood flow path and
first and second portions, the first and second portions having
different cross-sectional sizes when the stent is expanded. The
first and second portions of the stent are preferably constructed
to provide the stent with maximum radial strength when
expanded.
[0071] FIGS. 14A-14B and 15A-15B show one preferred system for
placing a funnel-shaped conduit in a patient's heart wall to
communicate a coronary vessel with a heart chamber. The system
includes a balloon 220 and a conduit 222. The balloon 220 is
generally straight over its length when unexpanded (FIG. 14A);
however, when expanded the balloon 220 assumes a tapered
orientation with a large end 224 and a small end 226 (FIG. 14B).
The conduit 222 is also preferably straight over its length when
supported by the balloon 220 in a collapsed orientation (FIG. 15A)
and funnel shaped when expanded by the balloon (FIG. 15B). It
should be understood that a tapered balloon is not necessary to
expand a tapered or funnel-shaped stent. For example, a straight
balloon could be used to expand a stent constructed to assume a
funnel-shaped configuration, with the inflated size of the balloon
preferably being sufficient to fully expand the large end of the
stent.
[0072] FIG. 16 depicts an exemplary application of the conduit 202
shown in FIGS. 15A-15B. The conduit 202 is shown positioned in a
heart wall 34 with a large diameter end 228 located in a heart
chamber such as the left ventricle 12 and a small diameter end 230
located in a coronary vessel such as LAD 30. It will be appreciated
that the shape, size and orientation of the conduit 202 in the
heart wall and coronary vessel may be varied from that shown in
FIG. 16. For example, the taper of the conduit wall may be
non-continuous or more gradual or severe than that shown in the
Figures, or either end of the conduit may be flush or within the
heart wall. Also, the conduit may be a rigid or expandable tubular
element.
[0073] FIGS. 17A-17B show one preferred funnel-shaped stent 240
that includes a plurality of stent elements in the form of struts
242 that move relative to each other as the stent moves to its
expanded orientation. The struts 242 are joined at nodes 244 which
move along with the struts as the stent 240 moves to its expanded
orientation. A plurality of open areas are defined between the
struts 242 through which blood may flow.
[0074] FIG. 17A shows the stent 240 in its collapsed orientation.
As shown, the stent 240 comprises a first portion 246, a second
portion 248 and a third portion 250. These three portions 246, 248,
250 are designed so that upon expansion they have different
diameters or cross-sectional dimensions. This may be achieved by
using different length struts 242 for the respective portions 246,
248, 250. The relative dimensions of the struts (and thus the
relative size of the expanded portions formed by the struts) may be
varied to achieve different sizes and shapes. Referring to FIG.
17B, the illustrated stent 240 is constructed so that the first
portion 246 expands to the smallest diameter while the third
portion 250 expands to the largest diameter. The second portion 248
expands to a middle diameter that tapers between the portions 246,
250. The struts 242 of the stent 240 preferably assume a maximum
load supporting position when fully expanded.
[0075] The stent 240 may be used in various applications, including
forming a blood flow path between a coronary vessel and a heart
chamber. The stent 240 (or another conduit constructed according to
this embodiment of the invention) may be used as a coronary stent
to improve blood flow through a coronary artery. In this
application, the stent 240 would be introduced into a peripheral
vessel and guided to the desired artery by conventional means.
[0076] FIGS. 18 and 19A-19C show another embodiment of the
invention providing a conduit for placing a coronary vessel in
communication with a heart chamber, the conduit including a
mechanism for internally supporting the interior of the vessel.
FIG. 18 shows a conduit 260 in the form of a rigid, tubular element
having a first end 262 and a second end 264. The conduit 260 has a
bore 266 passing therethrough that defines a blood flow path. A
mechanism 268 is provided to support the wall of a coronary vessel
with which the conduit 260 communicates. The mechanism 268 includes
a pair of support arms 270 preferably in the form of flexible
members made from any suitable material, such as stainless steel,
nitinol, polymers, etc. A pair of support arms 270 is shown;
however, any desired number of arms may be used. Each support arm
270 is secured to the conduit 260 at 272, for example, by welding,
brazing or adhesive. Alternatively, the support arms 270 may be
integrally formed as part of the conduit 260. The support arms 270
are provided with vessel supporting portions 274 which may be
formed by rounded lengths of wire 276, as shown.
[0077] Referring to FIG. 19A, which schematically illustrates one
preferred application of the conduit 260, the support arms 270 may
be folded against the wall of the conduit 260 so that the conduit
assumes a relatively low profile position. The conduit 260 is then
passed through an opening in the wall of a coronary vessel such as
the LAD 30 (FIG. 19A). The support arms 270 may be constrained
against the conduit 260 manually, with an instrument, or with a
removable sheath or cover. The conduit 260 is delivered into the
lumen 42 of the LAD and the heart wall 34 an amount sufficient to
place all (or substantially all) of the support arms 270 inside the
outer wall 40 of LAD 30 (FIG. 19B). At this point the support arms
270 spring out to the position shown in FIG. 18, which results in
the vessel supporting portions 274 of the arms contacting the walls
of the LAD 30 (FIG. 19C). The conduit is preferably configured so
that when the support arms are in this position the conduit end 262
extends into the left ventricle 12 while the conduit end 264
extends into the LAD 30.
[0078] FIG. 20 shows an another embodiment of a conduit with a
vessel supporting mechanism. The conduit is designated 280 and
preferably is a rigid tubular element as in the previous
embodiment. The conduit 280 has a mechanism 282 that supports the
wall of a coronary vessel in which the conduit is placed. The
support mechanism 282 includes three support arms 284 in the form
of hoops made from any suitable material, as discussed above. The
support arms 284 are also preferably flexible and secured to the
conduit 280 by welding, brazing or adhesive. The support arms 284
have vessel supporting portions 286 that contact and may slightly
distend the vessel wall. While three arms 284 are shown, any
desired number may of course be used.
[0079] FIG. 21 shows still another embodiment of a conduit with a
vessel supporting mechanism. The conduit is designated 290 and
preferably is a rigid tubular element as in the previous
embodiments. The conduit 290 is provided with a mechanism 292 for
supporting the wall of a coronary vessel. The vessel support
mechanism 292 includes a first pair of support arms 294 and a
second pair of support arms 296 in the form of tabs made from any
suitable material, as discussed above. The support arms 294 extend
generally along the longitudinal axis of the conduit 290 and are
adapted to contact the outer wall of a coronary vessel, while the
support arms 296 extend radially from the conduit 290 and are
adapted to contact the inner wall of the vessel. The support arms
294, 296 are preferably integrally formed with the conduit 290 and
are flexible to assume a low profile position. It will be noted
that the support arms 294, 296 could be separate members secured to
the conduit by suitable means such as welding, brazing or adhesive.
Also, although three arms 284 are shown, any desired number may be
used.
[0080] FIG. 22 shows yet another embodiment of a conduit with a
vessel supporting mechanism. The conduit is designated 300 and,
instead of being a rigid tubular element as in the previous
embodiments, is an expandable tubular element, for example, a
coronary stent. The conduit 300 has stent elements in the form of
struts 302 joined at nodes 304. The conduit 300 may be formed
substantially in the same manner as the stent 240 in FIGS. 17A-17B.
The conduit 300, however, is provided with a mechanism 306 for
supporting the wall of a coronary vessel. The vessel support
mechanism 306 in this embodiment includes a pair of extensions 308
that are preferably formed as an integral part of the stent struts
302. The extensions 308 extend generally along the longitudinal
axis of the conduit 290 so as to contact the outer wall of a
coronary vessel, thereby supporting the wall in the manner
discussed above. The ends 310 of the extensions 308 may be
unattached, as shown, or attached.
[0081] The conduit 300 may be mounted on a balloon or other
expandable member (not shown) in a collapsed orientation for
introduction into the coronary vessel and the heart wall. The
extensions 308 can be loaded on the balloon with the remaining
portion of the conduit 300. Once properly positioned in the heart
wall, the balloon is inflated to expand the conduit 300 to the
orientation shown in FIG. 22. It should be recognized that this
embodiment of the invention may be carried out using any expandable
conduit, the particular stent shown in FIG. 22 representing only
one possible construction. Also, the extensions 308 could be
separate members secured to the conduit 300 by suitable means such
as welding, brazing or adhesive. Finally, although two extensions
308 are provided on the illustrated conduit, any number of
extensions may be used.
[0082] It should be noted that, as used herein, the term conduit
refers to any structure that is capable of conveying fluid from one
point to another, for example, a tubular element with two or more
open ends. In view of the fact that various characteristics of the
conduit, for example, size, shape and surface configuration, may
vary depending on the application, it will be recognized that the
conduits in the illustrated embodiments are merely exemplary. For
instance, the conduit could be a rigid, flexible or expandable
tubular element formed of metal, polymers or composite materials
having solid or perforated walls. The conduit could be straight
over its length with the ends aligned or the ends could be offset,
the exterior surface of the conduit may be treated to enhance
fixation of the conduit in the heart wall, and the conduit may or
may not include a valve or other flow controlling mechanism.
Further, a conduit constructed according to the invention may be
used to deliver various pharmaceutical substances, such as
angiogenic growth factors or other substances that aid in the
perfusion of surrounding myocardial tissue.
[0083] It will be understood that the LAD 30 illustrated in the
Figures is but one example of a possible vessel which may be placed
in communication with a heart chamber.
[0084] Similarly, in the preferred embodiments the LAD 30 is placed
in communication with a heart chamber that contains blood, which,
in the illustrated embodiments, is the left ventricle 12. It will
be understood, however, that the invention may be used to place a
conduit in communication with any source of blood (arterial or
venous), for example, another heart chamber such as the left
atrium, or the aorta, pulmonary veins, etc.
[0085] It also will be appreciated that the various devices of the
invention incorporated in the illustrated embodiments may be used
together or separately, and the methods may be modified, carried
out by combining particular steps, or varying the sequence of
steps. Further, it will be understood that the embodiments may be
used in various types of procedures, for example, the surgical
approach depicted in FIG. 1, an open surgical procedure including a
median sternotomy, or a minimally invasive procedure utilizing one
or more relatively small access openings or ports. Endoscopes or
thoracoscopes may be used for visualization if the procedure is
truly minimally invasive. Additionally, rather than forming one or
more incisions in the patient's chest wall, an endovascular
approach may be used to guide various inventive devices to the
heart through the patient's vascular system to the heart, for
example, by introducing the devices into a peripheral vessel such
as the femoral artery. Similarly, 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.
[0086] 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.
* * * * *