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Claims  |
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What is claimed is:
1. An assembly for stabilizing the epicardium of the heart and occluding a
section of an artery, comprising:
a platform having a top surface and a bottom surface, at least a portion of
the bottom surface configured for contacting the epicardium of the heart;
at least one occluding member configured for adjustable movement relative
to the longitudinal axis of the platform;
means for removeably attaching the platform to the epicardium;
whereby the epicardium is stabilized by the platform being temporarily
attached to the epicardium; and
whereby a section of an artery is occluded by positioning the at least one
occluding member into engagement with the artery or epicardium above the
artery, thereby temporarily occluding the artery.
2. The assembly of claim 1, wherein the platform includes a plurality of
grooves for receiving suture threads for temporarily attaching the
platform to the epicardium using the suture threads.
3. The assembly of claim 2, wherein the suture threads extend into the
epicardium and attach to the platform thereby tensioning an operational
field defined by the platform.
4. The assembly of claim 1, wherein the platform has a substantially
U-shaped configuration for defining an operational field.
5. The assembly of claim 1, wherein the platform is formed of a rigid
biocompatible material taken from the group of materials including metal
alloys, stainless steel, and rigid polymers.
6. The assembly of claim 1, wherein the platform is formed from a flexible
biocompatible material.
7. The assembly of claim 6, wherein the flexible material includes a
flexible polymer material.
8. The assembly of claim 1, wherein the platform includes a first leg and a
second leg, the first and second legs being substantially parallel and
spaced apart, and a connecting member attached to the first leg and the
second leg.
9. The assembly of claim 8, wherein the connecting member further includes
a length defining the distance between the first leg and the second leg.
10. The assembly of claim 9, wherein the connecting member length is
adjustable so that the distance between the first leg and the second leg
can be adjusted.
11. The assembly of claim 8, wherein the connecting member is flexible so
that the first and second legs can pivot toward or away from each other
and can pivot in multiple planes.
12. The assembly of claim 8, wherein the first leg includes a first slot
for receiving a first occluding member, the first occluding member
configured for removable locking engagement with the first slot.
13. The assembly of claim 8, wherein the second leg includes a second slot
for receiving a second occluding member, the second occluding member
configured for removable locking engagement with the second slot.
14. The assembly of claim 13, wherein the first and the second occluding
members include a first end for contacting the artery or the epicardium
above the artery, a second end configured for grasping with forceps or
fingers, and an elongated body extending between the first and the second
ends.
15. The assembly of claim 14, wherein-the first and the second occluding
members include a rigid elongate core and a body portion covering at least
a portion of the rigid elongate core.
16. The assembly of claim 8, wherein the connecting member is malleable so
that the first leg and the second leg can be moved in any direction and
can be twisted to conform to the contour of the epicardium of the heart.
17. The assembly of claim 1, wherein the platform includes a plurality of
hooks for engagement with the epicardium to temporarily attach the
platform to the epicardium.
18. The assembly of claim 1, wherein at least a portion of the bottom
surface of the platform includes a concave portion so that when the
platform is pressed onto the epicardium it does not occlude an artery.
19. The assembly of claim 18, wherein the first and the second legs each
have a top surface and a bottom surface, at least a portion of the bottom
surface includes the concave portion so that when the legs are positioned
over an artery the concave portion does not occlude the artery.
20. The assembly of claim 1, wherein means are provided for attaching the
platform to the epicardium so that the epicardium can be tensioned and
stabilized within the platform.
21. An assembly for stabilizing the epicardium of the heart and occluding a
section of an artery, comprising:
a platform having a top surface and a bottom surface, at least a portion of
the bottom surface configured for contacting the epicardium of the heart;
at least one occluding member configured for adjustable movement relative
to the platform; and
an adjustable arm having a first end for removable attachment to the top
surface of the platform longitudinal axis of the and a second end for
removable attachment to a support that is stationary relative to the
platform, the adjustable arm having a first flexible configuration for
adjusting the distance between the platform and the support, and a second
rigid configuration for fixing the platform relative to the support;
whereby the epicardium is stabilized by applying compressive force to the
platform, the distance between the platform and the support defined by the
adjustable arm to increase or decrease the compressive force on the
epicardium by adjusting the distance between the platform and the support;
and
whereby a section of an artery can be occluded by positioning at least one
occluding member into engagement with the artery or the epicardium above
the artery, thereby temporarily occluding the artery.
22. The assembly of claim 21, wherein the platform includes a first slot
and a second slot, and wherein a first occluding member and a second
occluding member are retained respectively in the first slot and the
second slot.
23. The assembly of claim 22, wherein the first and the second occluding
members are configured for slidable and vertical movement in the first and
the second slots respectively, and upon twisting the members, for
releasable locking engagement in the first slot and the second slot
respectively.
24. The assembly of claim 22, wherein the platform includes a first leg and
a second leg, the first and second legs being substantially parallel and
spaced apart, and a connecting member attached to the first leg and the
second leg.
25. The assembly of claim 24, wherein the connecting member further
includes a length defining the distance between the first leg and the
second leg.
26. The assembly of claim 25, wherein the connecting member length is
adjustable so that the distance between the first leg and the second leg
can be adjusted.
27. The assembly of claim 24, wherein the connecting member is flexible so
that the first and second legs can pivot toward or away from each other
and can pivot in multiple planes.
28. The assembly of claim 24, wherein the first leg includes the first slot
for receiving the first occluding member.
29. The assembly of claim 24, wherein the second leg includes the second
slot for receiving the second occluding member.
30. The assembly of claim 24, wherein the connecting member is malleable so
that the first leg and the second leg can be moved in any direction and
can be twisted to conform to the contour of the epicardium of the heart.
31. The assembly of claim 24, wherein the first and the second legs each
have a top surface and a bottom surface, at least a portion of the bottom
surface having a concave portion so that when the legs are positioned over
an artery the concave portion does not occlude the artery.
32. The assembly of claim 21, wherein the platform includes a plurality of
grooves for receiving suture threads for attaching the platform to the
epicardium.
33. The assembly of claim 32, wherein the suture threads extend into the
epicardium and attach to the platform thereby tensioning an operational
field defined by the platform.
34. The assembly of claim 21, wherein the platform has a substantially
U-shaped configuration for defining an operational field.
35. The assembly of claim 21, wherein the platform is formed of a rigid
biocompatible material taken from the group of materials including
metallics, stainless steel, and rigid polymers.
36. The assembly of claim 21, wherein at least a portion of the platform is
formed from a flexible biocompatible material.
37. The assembly of claim 36, wherein the flexible material includes a
flexible polymer material.
38. The assembly of claim 21, wherein the first and the second occluding
members include a first end for contacting the artery, a second end
configured for grasping with forceps or fingers, and an elongated core
extending between the first and the second ends.
39. The assembly of claim 38, wherein the first and the second occluding
members include a rigid elongate core and a body portion covering at least
a portion of the rigid elongate core.
40. The assembly of claim 39, wherein the first end of the resilient body
is configured to provide atraumatic contact to occlude the artery.
41. The assembly of claim 21, wherein the adjustable arm includes a locking
mechanism allowing the arm to be flexible when the mechanism is in an
unlocked position, and rigid when the mechanism is in a locked position.
42. The assembly of claim 21, wherein at least a portion of the bottom
surface of the platform includes a concave portion so that when the
platform is pressed onto the epicardium it does not occlude an artery.
43. The assembly of claim 21, wherein a clamp is associated with the second
end of the adjustable arm, the clamp being configured for removable
attachment to the stationary support.
44. The assembly of claim 21, wherein means are provided for attaching the
platform to the epicardium so that the epicardium can be tensioned and
stabilized within the platform.
45. An assembly for stabilizing the epicardium of the heart and occluding a
section of an artery, comprising:
a platform having a top surface and a bottom surface, at least a portion of
the bottom surface configured for contacting the epicardium of the heart;
a first slot and a second slot disposed in the platform;
a first occluding member and a second occluding member retained
respectively in the first slot and the second slot, the first and the
second occluding members configured for adjustable movement relative to
the platform; and
an adjustable arm having a first end for removable attachment to the top
surface of the platform and a second end for removable attachment to a
support that is stationary relative to the platform, the adjustable arm
having a first flexible configuration for adjusting the distance between
the platform and the support, and a second rigid configuration for fixing
the platform relative to the support;
whereby the epicardium is stabilized by applying compressive force to the
platform, the distance between the platform and the support defined by the
adjustable arm which will increase or decrease the compressive force on
the epicardium by adjusting the distance between the platform and the
support; and
whereby a section of an artery can be occluded by positioning the first and
the second occluding members into engagement with the artery or the
epicardium above the artery, thereby temporarily occluding the artery.
46. The assembly of claim 45, wherein the platform includes a plurality of
grooves for receiving suture threads for attaching the platform to the
epicardium.
47. The assembly of claim 49, wherein the first and the second legs each
have a top surface and a bottom surface, at least a portion of the bottom
surface being recessed so that when the legs are positioned over an artery
the recessed portion does not occlude the artery.
48. The assembly of claim 46, wherein the suture threads extend into the
epicardium and attach to the platform thereby tensioning an operational
field defined by the platform.
49. The assembly of claim 45, wherein the platform includes a first leg and
a second leg, the first and second legs being substantially parallel and
spaced apart, and a connecting member attached to the first leg and the
second leg.
50. The assembly of claim 49, wherein the connecting member further
includes a length defining the distance between the first leg and the
second leg.
51. The assembly of claim 50, wherein the connecting member length is
adjustable so that the distance between the first leg and the second leg
can be adjusted.
52. The assembly of claim 51, wherein the connecting member is flexible so
that the first and second legs can pivot toward or away from each and can
pivot in multiple planes.
53. The assembly of claim 49, wherein the first leg includes the first slot
for receiving the first occluding member and the second leg includes the
second slot for receiving the second occluding member.
54. The assembly of claim 49, wherein the connecting member is formed from
a malleable material so that the first leg and the second leg can be moved
in any direction and can be twisted to conform to the contour of the
epicardium of the heart.
55. The assembly of claim 45, wherein the first and the second occluding
members are configured for slidable movement in the first and the second
slots respectively, and upon twisting the members, for releasable locking
engagement in the first slot and the second slot respectively.
56. The assembly of claim 45, wherein a clamp is associated with the second
end of the adjustable arm, the clamp being configured for removable
attachment to the stationary support.
57. The assembly of claim 45, wherein at least a portion of the bottom
surface of the platform is recessed so that when the platform is pressed
onto the epicardium it does not occlude an artery.
58. The assembly of claim 45, wherein means are provided for attaching the
platform to the epicardium so that the epicardium can be tensioned and
stabilized within the platform.
59. A method for stabilizing the heart and occluding an artery, the method
steps comprising:
providing a platform having a top surface and a bottom surface, at least a
portion of the bottom surface configured for contacting the epicardium of
the heart, a first occluding member and a second occluding member
configured for slidable and vertical movement within the platform;
positioning the platform on the epicardium;
positioning the first and the second occluding members over a section of
artery;
temporarily occluding the section of artery with the occluding members;
performing a medical procedure;
releasing the occluding members and detaching the platform from the
epicardium; and
removing the tool from the patient.
60. The method of claim 59, wherein the platform is removably attached to
the epicardium by suturing threads connected to the platform and to a
portion of the epicardium.
61. The method of claim 59, wherein the step of providing a platform
includes providing a platform having a substantially U-shape, a first leg
and a second leg connected by a connector, and a first slot in the first
leg and a second slot in the second leg for slidably receiving the first
and second occluding members respectively.
62. The method of claim 61, wherein the step of positioning the occluding
members includes sliding the first and the second occluding members in the
first and the second slots respectively for positioning the occluders over
the section of an artery.
63. The method of claim 62, wherein the first and the second occluding
members are temporarily locked in the first and the second slots, the
occluding members occluding the section of artery.
64. The method of claim 61, wherein the first leg is moveable relative to
the second leg, the further method step including adjusting the first leg
relative to the second leg to position the first occluding member and the
second occluding member over a section of artery.
65. The method of claim 59, wherein the step of providing the platform
further includes providing an adjustable arm having a first end for
removable attachment to a top surface of the platform and a second end for
removable attachment for a support that is stationary relative to the
platform, the adjustable arm having a first flexible configuration for
adjusting the distance between the platform and the support, and a second
rigid configuration for fixing the platform relative to the stationary
support.
66. The method of claim 65, wherein after the step of positioning the
platform on the epicardium, the method steps for stabilizing the
epicardium include:
clamping the adjustable arm to the stationary support;
adjusting the distance between the stationary support and the epicardium by
pressing the platform on the epicardium and locking the adjustable arm in
the second rigid configuration thereby fixing the platform relative to the
support and the epicardium providing a stable surface on the epicardium.
67. The method of claim 66, wherein after the step of performing the
medical procedure, the adjustable arm is unclamped from the stationary
support and the platform is removed from the epicardium. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
The invention relates generally to a system and method of stabilizing a
patient's beating heart during a medical procedure, such as coronary
artery bypass grafting (CABG). More specifically, the invention relates to
an apparatus and method for stabilizing the epicardium and occluding the
section of the artery to receive a graft vessel.
In a typical CABG procedure on a stopped heart, the patient undergoes a
median sternotomy to provide access to the heart area and is put on
cardiopulmonary bypass equipment (CPB) to oxygenate the blood and allow
the heart to be stopped. These procedures are well known, are safe and are
widely accepted for a wide range of medical procedures performed on the
heart. A more thorough discussion of a typical CABG procedure can be found
in Manual of Cardiac Surgery, Second Edition, by Bradley J. Harlan, MD,
Albert Starr, MD and Fredric M. Harwin, BFA, MS, 1995, and a discussion of
open heart procedures can be found in Textbook of Interventional
Cardiology, Eric J. Topol, 1990, chapters 43-44, pages 831-867,
incorporated herein by reference.
It should be understood that while the foregoing CABG procedures are
generally regarded as safe and widely accepted, they are not without
risks. As is known, when the patient is put on cardiopulmonary bypass
equipment, the blood is continuously pumped extracorporeally where it is
oxygenated and then returned to the body. Any time the blood is removed
from the body there is the risk of infection such as sepsis or other
infections that can be serious if not detected and treated. During the
oxygenation process, micro-emboli are introduced that are believed to be a
major cause of neurological damage which can be temporary or permanent.
While the heart and lungs are being bypassed, the heart is infused with
cardioplegic fluid to stop the heart from beating and limit damage to the
muscle cells due to lack of blood. However, the lungs are not perfused
with blood for many hours and this can cause many problems. Also, there is
a need to prime the CPB pump with about one liter of fluid. This fluid is
pumped into the patient's body in the first few seconds of CPB resulting
in a hemodilution of about 20%. As the blood is transported through many
feet of tubing and various oxygenators, heat exchangers, and pumps, it is
in contact with foreign materials. This contact induces compliment
activation which can lead to pulmonary dysfunction, renal dysfunction and
further embolic complications. Further, the equipment needed to perform
cardiopulmonary bypass is expensive and requires specialized medical
personnel to operate and monitor.
During coronary artery bypass procedures using the beating heart approach,
the region of the heart which receives the graft vessel must be stabilized
so that the graft and suturing procedure can be performed on a
substantially stationary epicardium. Presently, this is often performed by
threading two sutures through the myocardium with curved needles, on
either side of the recipient coronary artery at the site of the
anastomosis. The sutures are tensioned to lift the heart and to hold the
coronary artery stationary. Suture threads with curved needles swaged on
one end are available for this use. Also, suture threads may be used to
loop around and tighten the section of artery to be grafted, thereby
occluding the artery during the procedure. Again, with the heart beating,
placing these suture loops around the artery is difficult due to the
movement of the heart and the epicardium surrounding the artery.
Placement of the suture loops may be somewhat difficult, as the heart is
beating. The tip of the needle must be placed on the heart, and rotation
of the surgeon's wrists must be performed to insert the needle through the
myocardium or epicardium. Unpredictable motion of the epicardial surface
during needle placement may cause laceration of the heart, puncture of the
wall into the ventricle, or puncture of a coronary artery. It is therefore
useful to stabilize the anastomotic area during the surgical procedure.
There are devices and methods that facilitate the performance of cardiac
procedures such as heart valve repair and replacement, coronary artery
bypass grafting, and the like, using minimally invasive techniques to
eliminate the need for a gross thoracotomy. For example, U.S. Pat. No.
5,425,705 to Evard et al. discloses an apparatus and method for
thoracoscopically arresting the heart and establishing cardiopulmonary
bypass, thus facilitating a variety of less-invasive surgical procedures
on and within the heart and great vessels of the thorax. In one
embodiment, Evard provides a thoracoscopic system for arresting a
patient's heart including a clamp configured for introduction into the
patient's thoracic cavity through a percutaneous intercostal penetration
in the patient's chest. The clamp is positionable about the patient's
ascending aorta between the coronary arteries and the brachiocephalic
artery. The clamp is coupled to the distal end of an elongated handle for
manipulating the clamp from a location outside of the patient's thoracic
cavity.
It is known to use surgical clips or clamps for the purpose of clamping
vessels or manipulating tissue. Typically, such clamps have a pair of
movable jaws biased by a spring into a closed position, allowing the clamp
to be placed on a vessel or portion of tissue and be firmly retained
thereon. Examples of such clamps can be found in U.S. Pat. No. 4,932,955
to Merz et al.; U.S. Pat. No. 4,605,990 to Wilder et al.; U.S. Pat. No.
5,074,870 to Von Zeppelin; U.S. Pat. No. 3,809,094 to Cook; U.S. Pat. No.
4,404,677 to Springer; U.S. Pat. No. 4,051,844 to Chiulli; and U.S. Pat.
No. 4,988,355 to Leveen et al.
Outside of the field of cardiac surgery, U.S. Pat. No. 5,415,666 to Gourlay
et al. discloses a tethered clamp retractor used for tissue manipulation.
The tissue manipulation system includes a tethered clamp, a clamp
applicator for positioning the clamp through a trocar sleeve and applying
the clamp to a tissue location in the abdominal cavity, and a rigid
positioning shaft for engaging the clamp and/or tether to manipulate the
clamp.
In view of the shortcomings of the prior art devices, there is a specific
need for an apparatus and method for locally stabilizing an anastomotic
site during a beating heart coronary artery grafting procedure. What has
been needed and heretofore not available is a method of stabilizing the
beating heart during a medical procedure without having to perform CPB and
subjecting the patient to the attendant risks and complications. The
present invention solves the problems of the prior art methods without the
resulting risks.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method of use for
locally stabilizing an anastomotic site of a beating heart during a
cardiac surgical procedure, and occluding a section of artery to receive a
bypass graft. More specifically, an apparatus is provided to stabilize the
epicardium in an area referred to herein as the operational field, which
includes the area where a section of a coronary artery receives a bypass
graft. The invention further includes means for occluding the artery
during the bypass grafting procedure.
The invention includes a platform having a top surface and a bottom
surface, with at least a portion of the bottom surface configured for
contacting the epicardium of the heart. A pair of occluding members are
configured for slidable and vertical movement within the platform for
positioning over and occluding a section of artery. The platform can be
sutured or otherwise attached to the epicardium thereby defining an
operation field within the platform on the epicardium, and stabilizing the
epicardium within the operational field. By temporarily attaching the
platform to the epicardium, a slight tensioning or stretching of the
epicardium occurs which results in a stabilizing effect around the
platform. The occluding members are positioned over and into contact with
the epicardium surface over the artery, and temporarily locked in place
thereby temporarily occluding a section of artery in the operational
field.
In one embodiment, the platform has a substantially U-shaped configuration
for defining the operational field. The platform includes a pair of legs
connected by a connecting member, with the legs each having a slot in
which the occluding member is retained for slidable movement. The
connecting member can be adjustable so that the distance between the legs
can be adjusted, thereby adjusting the size of the operational field that
is stabilized during the grafting procedure. Alternatively, the connecting
member can be malleable thereby permitting the legs to be pivoted, thereby
adjusting the distance and angle between the legs so that they can be more
easily positioned over the artery to be occluded.
One advantage of the present invention is to provide occluding members that
are slidably adjustable within the slots of the legs in the platform. The
occluding members can be adjusted so that they can be positioned over the
section of artery to be grafted and then temporarily locked in place by
twisting the members into locking engagement with the slots.
In one embodiment, to assist in further stabilizing the operational field,
an adjustable arm having a first end for removable attachment to the top
surface of the platform is provided. The adjustable arm has a second end
for removable attachment to a support that is stationary relative to the
platform. Typically, the stationary support can include a rib retractor on
which the second end of the adjustable arm is clamped.
In the preferred method of stabilizing the epicardium and occluding the
section of artery to be grafted, the platform is positioned over the
artery to be grafted. The platform can be sutured in place or attached by
other means, generally if the adjustable arm is not attached. Once the
platform is attached to the epicardium, the area becomes stabilized so
that the occluding members can be positioned over the artery and locked
into engagement in the slots, thereby occluding the artery. The medical
procedure is then performed, wherein a vessel is grafted in an end-to-side
grafting procedure which is known in the art. After the medical procedure
is performed, the platform is removed from the epicardium.
In an alternative method, the platform with the adjustable arm attached is
positioned on the epicardium and the second end of the adjustable arm is
temporarily attached to the stationary support. The adjustable arm, since
it is flexible, can be used to position the platform and slightly compress
the platform onto the epicardium, whereby the adjustable arm is then
locked so that it is rigid. In the locked position, the adjustable arm is
substantially rigid and applies slight compressive force to the platform,
thereby stabilizing the epicardium. Alternatively, the adjustable arm can
be used to pull the platform, which is attached to the epicardium,
upwardly thereby tensioning and stabilizing the operational field.
Thereafter, the occluding members are positioned over the artery and
locked into place in the slots in order to occlude the artery during the
grafting procedure. After the grafting procedure is completed, the
adjustable arm is unlocked, thereby returning the arm to flexibility, and
the device is removed from the patient.
Other features and advantages of the invention will become apparent from
the following detailed description, taken in conjunction with the
accompanying drawings which illustrate, by way of example, the features of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of the platform used to stabilize the epicardium.
FIG. 2 is a side elevational view depicting the platform of FIG. 1 used to
stabilize the epicardium.
FIG. 3 is a top view depicting the platform wherein the connecting member
for the legs is adjustable.
FIG. 4 is a top view of the platform wherein the connecting member is
malleable so that the legs can be adjusted.
FIG. 5 is an elevational view depicting the platform wherein the occluding
member is positioned over an artery.
FIG. 6 is an elevational view of the platform positioned on the epicardium
with the occluding member in contact with and occluding the artery.
FIG. 7 is an elevational view of the platform depicting the occluding
members at an angle to provide easier access to the operational field.
FIG. 8 is a front elevational view of the elongate body which forms part of
the occluding member.
FIG. 9 is a side elevational view of the elongate body of FIG. 8 turned
90.degree..
FIG. 10 is cross-sectional view depicting a body portion for receiving the
elongate member thereby forming the occluding member.
FIG. 11 is an elevational view of the body portion of FIG. 10.
FIG. 12 is a front elevational view of the body portion depicting the
occluding end which contacts the. artery.
FIG. 13 is a cross-sectional view of the body portion of FIG. 12, depicting
the recess for receiving the elongate body of FIGS. 8 and 9.
FIG. 14 is an elevational view of an alternative embodiment of the rigid
elongate core.
FIG. 15 is a front elevational view of an alternative embodiment depicting
the body portion of the occluding member, further depicting the more
circular occluding end for contacting the coronary artery.
FIG. 16 is a top elevational view of the platform depicting angulated
slots.
FIG. 17 is a front elevational view depicting the platform of FIG. 16, in
which the angulation of the slots are more clearly depicted.
FIG. 18 is an elevational view of an adjustable arm for use in conjunction
with the platform.
FIG. 19 is a cross-sectional view of a link associated with the adjustable
arm.
FIG. 20 is a top elevational view of the adjustable arm connected to a rib
retractor.
FIG. 21 is a top elevational view of the platform positioned on the
epicardium of the heart and further depicting the occluding members in
contact with a section of the artery to receive a bypass graft vessel.
FIG. 22 is a top elevational view depicting the platform being connected to
the adjustable arm.
FIG. 23 is a top elevational view depicting the platform attached to the
adjustable arm, further depicting the platform being positioned on the
epicardium and the occluding members occluding a section of an artery.
FIG. 24 is an elevational view of a wire retractor for use with the
platform stabilizing invention.
FIG. 25 is a perspective view of the platform positioned on the epicardium
depicting the retractor of FIG. 24 used to pull back the epicardium to
expose the arteriotomy site.
FIG. 26 is a perspective view of the platform positioned on the epicardium,
depicting the retractor of FIG. 24 positioned through a slot in the
platform and holding back the epicardium to expose the arteriotomy site.
FIG. 27 is a perspective view of the platform further depicting an
alternative embodiment of the occluding members for occluding the artery.
FIG. 28 is a partial view of one leg of the platform, in perspective,
depicting a carriage for slidable movement along the leg.
FIG. 29 is an end elevational view, partially in cross-section, of the leg
and carriage assembly of FIG. 28, with the occluding member retained in
the carriage member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an apparatus and method for use for
stabilizing the epicardium of a beating heart during a cardiac surgical
procedure, such as bypass grafting, and to occlude a section of artery
receiving the bypass graft vessel. The apparatus of the invention
stabilizes the epicardium in the operational field, which includes the
area where a section of a coronary artery receives a bypass graft vessel.
The invention further includes the apparatus and method for occluding a
section of the artery where the bypass graft procedure occurs.
In keeping with the invention, as shown in FIGS. 1-4, platform 10 has a
U-shaped configuration which includes first leg 11 and second leg 12 in
substantially parallel relationship and spaced apart. The first and second
legs are connected by connecting member 13 which, in FIGS. 1 and 2, is a
rigid member which maintains the first and second legs in a parallel
relationship. Platform 10 also includes top surface 14 and bottom surface
15, where at least a portion of the bottom surface is configured for
contact with the epicardium of the heart.
As depicted in FIG. 2, bottom surface 15 of the platform is concave. First
concave portion 18 is provided so that when the bottom surface of the
platform is pressed onto the epicardium or attached to the epicardium, in
the area of a coronary artery, the concave portion is positioned over the
coronary artery so that it does not inadvertently occlude the artery. As
will be described herein, means are provided to intentionally occlude a
section of the artery, however, it is not intended that the platform
itself, and importantly the bottom surface inadvertently occlude a portion
of artery during the medical procedure. The radius of concave portion 18
can vary depending upon the application, and may range from approximately
3 inches to about 12 inches. Preferably, the radius of concave portion 18
is approximately 8 inches. It also may be desirable to provide second
concave portion 19 that has a smaller radius than the first concave
portion. The second concave portion can then be positioned over the artery
without occluding it. The second concave portion 19 has a radius in the
range of about 0.5 to 3.0 inches and preferably is about 1.3 inches.
The area encompassed by the boundaries of first leg 11, second leg 12 and
connecting member 13 define operational field 20. If it is desired to
provide a larger or smaller operational field, the dimensions of platform
10, and specifically the distance between first leg 11 and second leg 12
can be varied to suit the particular application. In order to provide
flexibility for the surgeon performing the bypass procedure, it may be
desirable to vary the size of the operational field 20 during the
procedure. Depicted in FIGS. 3 and 4, the distance and angle between first
leg 11 and second leg 12 is adjustable. In FIG. 3, connecting member 13
can be a two-piece member, one slidable within the other in a telescoping
manner, so that the distance between the first leg and the second leg can
be varied, while the legs remain parallel to each other. The platform
depicted in FIGS. 1-3 can be formed of a rigid material including metal
alloys, stainless steel, polycarbonate, Ultem.RTM. (Ultem.RTM. is
available from General Electric Plastics, Pitsfield, Mass.) or rigid
polymers. Importantly, the materials must be biocompatible, and preferably
sterilizable, however, the platform is configured and designed for single
use applications and would not require further sterilization after a
single procedure.
Referring to an alternative embodiment of platform 10, as shown in FIG. 4,
connecting member 13 is formed from a malleable material, which provides
flexibility so that first leg 11 and second leg 12 can be essentially
pivoted apart to increase or decrease the size of operational field 20.
Examples of malleable materials include a malleable wire made from 304
stainless steel wire covered with a polymer, such as polyethylene,
urethane, and silicone.
Since the function and purpose of platform 10 is to provide stabilization
of the epicardium in the operational field, it is intended that it be used
either alone, or in conjunction with further apparatus as will be
described herein. When used alone, it may be desirable to temporarily
attach platform 10 to the epicardium. In that regard, as depicted in FIGS.
1-4, a plurality of grooves 21 are provided on top surface 14. The grooves
are indentations for receiving a suture thread that is passed through the
epicardium with a needle or other means, and positioned in the groove and
tightened so that the platform can be sutured to the epicardium. In the
specific embodiments depicted in the drawings, there are four grooves 21
for receiving sutures only two of which are shown in the figures, thereby
providing four attachment points on platform 10. At least three attachment
points are preferred, and more attachment points may be desired. With at
least three attachment points between platform 10 and the epicardium,
operational field 20 can be placed in tension, which provides
stabilization. More or less grooves 21 can be provided, and it is
contemplated that other attachment means can be substituted for the
grooves, including apertures passing through platform 10, tabs attached to
the sides or top of the platform, and similar attachment means. In
addition, in some circumstances suture threads may not be ideal and it may
be desirable to use other attachment means such as hooks, screws or
helical fasteners. For example, hooks on the sides of platform 10 or on
bottom surface 15 may be used as attachment points. Further, helical
screws such as the Origin Tacker.RTM., manufactured and sold by Origin
MedSystems, Menlo Park, Calif., can be used to attach platform 10 to the
epicardium. The attachment means is biocompatible and in the case of
suture threads, helical screws, and similar attachment means, they are
bioabsorbable and will be absorbed into the body over a short period of
time.
While dimensions may vary depending upon a particular application, in a
preferred embodiment the distance between first leg and second leg is in
the range of approximately 0.2 to 2.0 inches. The length of legs 11,12
also will vary depending upon the application, and preferably are in the
range of about 0.5 to 3.5 inches. In the embodiments depicted in FIGS. 3
and 4, the distances between the legs can be varied by the surgeon at the
time of the procedure.
The platform may be adapted to include means for occluding a section of the
artery to be grafted so that the platform provides not only a
stabilization function, but an occluding function during the bypass
procedure. As depicted in FIGS. 1, 3-7, 16-17, and 21-23, the platform
includes a pair of s | | |
