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Description  |
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DESCRIPTION
1. Field of the Invention
This invention relates to retractors, and more particularly to an access
platform that facilitates access to the interior of the chest cavity
during surgical procedures.
2. Background of the Invention
Diseases of the cardiovascular system affect millions of people each year
and are a leading cause of death in the United States and throughout the
world. The cost to society from such diseases is enormous both in terms of
lives lost and the cost of treating cardiac disease patients through
surgery. A particularly prevalent form of cardiovascular disease is a
reduction in the blood supply to the heart caused by atherosclerosis or
other conditions that create a restriction in blood flow at a critical
point in the cardiovascular system leading to the heart. In many cases, a
blockage or restriction in the blood flow leading to the heart can be
treated by a surgical procedure known as a Coronary Artery Bypass Graft
(CABG) procedure, which is more commonly known as a "heart bypass"
operation. In the CABG procedure, the surgeon either removes a portion of
a vein from another part of the body to use as a graft and installs the
graft at points that bypass the obstruction to restore normal blood flow
to the heart or detaches one end of an artery and connects that end past
the obstruction while leaving the other end attached to the arterial
supply to restore normal blood flow to the heart.
Although the CABG procedure has become relatively common, i.e., heart
bypass surgery is performed in one of every thousand persons in the United
States, the procedure is lengthy and traumatic and can damage the heart,
the central nervous system, and the blood supply. In a conventional CABG
procedure, the surgeon cuts off the blood flow to the heart and then stops
the heart from beating in order to install the graft. Thus, in order to
perform the conventional CABG procedure, the surgeon must make a long
incision down the middle of the chest, saw through the entire length of
the sternum, spread the two halves of the sternum apart, and then perform
several procedures necessary to attach the patient to a cardiopulmonary
bypass machine to continue the circulation of oxygenated blood to the rest
of the body while the graft is sewn in place.
The CABG procedure further requires that a connection for the flow of blood
be established between two points that "by pass" a diseased area and
restore an adequate blood flow. Typically, one end of a graft is sewn to
the aorta, while the other end of the graft is sewn to a coronary artery,
such as the left anterior descending (LAD) artery that provides blood flow
to the main muscles of the heart. This procedure is known as a "free
bypass graft." Alternatively, the IMA pedicle is dissected off of the
chest wall, while still attached to its arterial supply, and attached to
the LAD past the obstruction. This procedure is known as an "in situ
bypass graft."
In an in situ bypass graft, the IMA must be dissected from its connective
tissue until there is sufficient slack in the IMA to insure that the graft
does not kink after it is installed. The IMAs, left and right, extend from
the subclavian arteries in the neck to the diaphragm and run along the
backside of the rib cage adjacent the sternum. During a conventional in
situ bypass graft, typically the left half of the sternum is raised to
increase the surgeon's access to the left IMA (LIMA) and the heart. A
device used for this type of sternal retraction is disclosed in United
Kingdom Patent Application No. GB 2267827 A, "A device for Internal
Mammary artery dissection."
Although several efforts have been made to make the CABG procedure less
invasive and less traumatic, most techniques still require cardiac bypass
and cardioplegia (stoppage of the heart). The safety and efficacy of CABG
procedure could be improved if the surgeon could avoid the need to stop
the heart from beating during the procedure, thereby eliminating the need
to connect the patient to a cardiopulmonary bypass machine to sustain the
patient's life during the CABG procedure and, thus, eliminate the need for
the lengthy and traumatic surgical procedures necessary to connect the
patient to a cardiopulmonary bypass machine. In recent years, a small
number of surgeons have begun performing CABG procedures using surgical
techniques especially developed to enable surgeons to perform the CABG
procedure while the heart is still beating. In such procedures, there is
no need for any form of cardiopulmonary bypass, no need to perform the
extensive surgical procedures necessary to connect the patient to a
cardiopulmonary bypass machine, cardioplegia is rendered unnecessary, the
surgery is much less invasive and traumatic, and the entire procedure can
typically be achieved through one or two comparatively small incisions
(thoracotomies) in the chest.
Despite these advantages, the beating-heart CABG procedure is not widely
practiced, in part, because of the difficulty in performing the necessary
surgical procedures with conventional instruments while the heart is still
beating. If specially designed instruments were available so that the CABG
procedure could more easily be performed on the beating heart, the
beating-heart CABG procedure would be more widely practiced and the
treatment of cardiovascular disease would be improved in a significant
part of the cardiovascular disease patient population.
Since the "beating-heart" CABG procedure is performed while the heart
muscle is continuing to beat or contract, an anastomosis is difficult to
perform because the blood continues to flow and the heart continues to
move while the surgeon is attempting to sew the graft in place. The
surgical procedure necessary to install the graft requires placing a
series of sutures through several extremely small vessels that continue to
move during the procedure. The sutures must become fully placed so that
the graft is firmly in place and does not leak. It is also important that
the procedure be performed rapidly because the blood flow through the
artery may be interrupted or reduced during the procedure to allow the
graft to be installed. This can cause ischemia, which should be minimized.
Also, the surgeon's working space and visual access are limited because
the surgeon may be working through a small incision in the chest or may be
viewing the procedure on a video monitor, such that the site of the
surgery is viewed via a surgical scope.
The "beating-heart" CABG procedure could be greatly improved if the
surgeon's working space and visual access to the heart and the IMA were
increased and improved. Current methods to increase and improve the
surgeon's working space and visual access include laterally spreading or
retracting the ribs with a conventional rib spreader/retractor, and then
vertically displacing one of the retracted ribs relative to the other
retracted rib to create a "tunnel" under the rib cage. To vertically
displace one of the retracted ribs, some force external to the rib
spreader must be applied to the rib. Typically, a surgeon's assistant will
push or pull upwardly on the rib with a device having a rib blade inserted
under the rib. However, the surgeon's assistant must then hold the rib in
a vertically displaced position for the duration of the IMA dissection,
resulting in an undesirable addition of another set of hands around the
surgical area.
Another method used by surgeons to vertically displace the retracted rib is
to insert a rib blade under the retracted rib and then attach the rib
blade to a winch located above the patient. The winch is then operated to
pull upwardly on the rib and hold it in a vertically displaced position.
However, it is not at all uncommon for the patient to be raised off the
operating table by the winch. This is undesirable because if the rib
begins to crack or break, the weight of the patient's body will cause the
rib to continue to break until the patient reaches the operating table.
While using these methods to vertically displace one of the retracted ribs,
it may be desirable to further increase a surgeon's working space and
visual access by depressing the sternum or the other retracted rib.
However, depression of the sternum or the other retracted rib undesirably
adds further sets of hands around the surgical site.
Furthermore, these methods and devices tend to limit where the thoracotomy
can be performed. For example, if the thoracotomy is performed on the
lateral side of the chest, the conventional rib spreader would tend to
"stand-up" vertically from the ribs it is retracting such that it would
intrude on the surgeon's working space. In addition, if a winch is used to
offset the ribs, the lifting action of the winch will tend to rotate the
patient to an undesirable and often unstable position for performing the
IMA.
Equally important to improving the "beating heart" CABG procedure, is the
ability to retract the soft tissue around the incision in the chest to
draw the soft tissue away from the surgeon's working area. However, none
of the methods or devices described above provide the ability to perform
soft tissue retraction.
Thus, in view of the shortcomings of these devices and methods for
increasing a surgeon's working space and visual access during a
"beating-heart" CABG procedure, it would be desirable to have a device
that is capable of laterally spreading the ribs and vertically displacing
opposing retracted ribs relative to each other, that is capable of
depressing the sternum, that is self-contained such that the force
necessary to spread and vertically displace the ribs, and the force
necessary to depress the sternum, is applied by the access platform itself
rather than through additional external devices, that does not limit the
location where a thoracotomy can be performed, and that is capable of soft
tissue retraction.
SUMMARY OF THE INVENTION
The access platform of the present invention serves to facilitate the
dissection of an internal mammary artery (IMA), including both proximal
and distal dissection, and access to the heart during a "beating heart"
Coronary Artery Bypass Graft (CABG) procedure by increasing the surgeon's
working space and visual access. The access platform of the present
invention is preferably capable of laterally spreading the ribs,
vertically displacing the opposingly retracted ribs relative to each other
and depressing the sternum to cause a "tunnel" effect under the retracted
ribs. Moreover, it is preferably self-contained such that the force
necessary to spread and vertically displace the ribs is applied by the
access platform itself rather than through additional external devices.
The access platform preferably comprises a first and a second blade
interconnected to a spreader member that laterally drives the blades apart
or together, support pads interconnected to the blades, and a
bi-directional torsional member interconnected to a blade and the spreader
member. The torsional member causes the interconnected blade to be
vertically displaced in either direction and, thus, increases the
surgeon's working space and visual access to the IMA.
In addition, the access platform preferably includes an integrated tissue
retractor, a hinged connector interconnected to the blades and the
spreader member, and a port interconnected to the blades. The tissue
retractor advantageously draws the soft tissue around an incision away
from the surgeon's working area. The port advantageously provides a mount
for a heart stabilizer, a scope for IMA take down, an IMA clamp, an IMA
holder or other tools necessary for a "beating heart" CABG procedure. The
hinged connector advantageously pivots the access platform away from the
surgeon's working area.
It is an object of the present invention to provide an improved access
platform.
Another object of the present invention is to provide an improved tissue
retractor.
Further objects and advantages of the present invention will become
apparent from a consideration of the drawings and the ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of an embodiment of an access platform of the present
invention disposed over the chest of a patient.
FIG. 2 is an isometric view of the access platform shown in FIG. 1 less the
tissue retractor elements.
FIG. 3 is an exploded isometric view of a harmonic gear drive in the hub
element of the access platform in FIG. 1.
FIG. 4 is a cross-sectional view of a reduction gear assembly in the
torsional member element of the access platform taken along line 4--4 in
FIG. 1.
FIG. 5A is an isometric view of a blade, a blade arm and a tissue retractor
assembly of the access platform shown in FIG. 1.
FIG. 5B is an isometric view of an alternate embodiment of the tissue
retractor assembly shown in FIG. 5A.
FIG. 6 is a front view of the access platform with the tissue retractors
disengaged.
FIG. 7 is a front view of the access platform with the tissue retractors
engaged.
FIG. 8 is a top view of a second embodiment of the access platform of the
present invention.
FIG. 9 is a partial front view of the access platform shown in FIG. 8.
FIG. 10 is a side view of the access platform as viewed along a line 10--10
in FIG. 8.
FIG. 11 is a front view of a third embodiment of the access platform of the
present invention.
FIG. 12 is a front view of the access platform shown in FIG. 11 with the
torsional member engaged.
FIG. 13A is an isometric view of a fourth embodiment of the access platform
of the present invention.
FIG. 13B is an isometric view of an alternate embodiment of the access
platform shown in FIG. 13A.
FIG. 14 is an elevation view of a pry bar engaging the blade arm of the
access platform in FIG. 13.
FIG. 15 is a top view of the pry bar.
FIG. 16 is an isometric view of a fifth embodiment of the access platform
of the present invention.
FIG. 17 is a top view of a sixth embodiment of an access platform of the
present invention.
FIG. 18 is a rear view of the access platform in FIG. 17.
FIG. 19 is an isometric view of a seventh embodiment of an access platform
of the present invention.
FIG. 20 is a front elevation view of an eighth embodiment of an access
platform of the present invention.
FIG. 21 is a top view of a ninth embodiment of an access platform of the
present invention.
FIG. 22 is a partial front elevation view of the access platform in FIG.
21.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now in detail to the drawings, therein illustrated is a novel
access platform that facilitates the dissection of an internal mammary
artery (IMA), including both proximal and distal dissection, and access to
the heart during a "beating heart" Coronary Artery Bypass Graph (CABG)
procedure by increasing the surgeon's working space and visual access.
Turning to FIG. 1, the access platform 10 incorporating a preferred
embodiment of the present invention, is shown disposed over the outline of
a patient's chest P. An incision in the patient's chest P adjacent to the
LIMA (shown in phantom) exposes an LAD artery on the exterior of the
patient's heart. Preferably, the access platform 10 comprises a pair of
blades 50 and 51, a pair of support pads 80 and 81, a pair of tissue
retractors 70 and 71, a pair of torsional members 30 and 31, and a
spreader member 12. The torsional members 30 and 31 and the spreader
member 12 preferably extend away from the blades 50 and 51 and the tissue
retractors 70 and 71 and, thus, the chest incision, in a plane relatively
parallel to the patient's chest. As a result, the access platform 10
advantageously maintains a low profile that remains substantially clear of
the surgeon's working space.
Referring to FIG. 2, the components of the access platform 10 are shown
less the tissue retractors 70 and 71. The spreader member 12 preferably
comprises a rotatable hub 14 including operably coupled upper and lower
hub halves 17 and 16. A pair of spreader arms 19 and 18 extend from the
upper and lower hubs 17 and 16, respectively, and connect to the torsional
members 31 and 30, respectively. Preferably, the hub 14 includes a
harmonic gear drive 20 used to rotate the upper hub half 17 relative to
the lower hub half 16 and, thus, spread or close the spreader arms 18 and
19 to retract or relax the patient's ribs.
Turning to FIG. 3, the harmonic gear drive 20 comprises ring gears 21 and
22, a pinion 24, idler gears 26 and 27, and a drive hub 28. The ring gears
21 and 22 are formed on the inner walls of the upper and lower hub halves
17 and 16, respectively. The idler gears 26 and 27 are operably connected
to the pinion 24 and ring gears 21 and 22. Preferably, the effective gear
ratios between the ring gears 21 and 22 are in the range of about 20-40:1,
and the gear ratio between the pinion 24 and the ring gears 21 and 22 are
in the range of about 3-5:1. Thus, only a relatively low torque is needed
to turn the drive hub 28, which is connected to the pinion 24, to drive
the ring gears 21 and 22 at a relatively high torque to rotate the upper
hub 17 relative to the lower hub 16 and spread a patient's ribs apart.
Alternatives to the harmonic gear drive 20 include the use of a ratchet
mechanism, a wrap spring mechanism or a lock nut mechanism (not shown)
with the hub 14. Thus, a wrench or special tool can be attached to the
upper hub half 17 to rotate it relative to the lower hub half 16 while the
operator holds onto the spreader arm 18 or the lower hub half 16 with
another wrench or special tool. Once the upper hub half 17 is rotated to a
desired position relative to the lower hub half 16, the ratchet or wrap
spring mechanism prevents reverse rotation of the upper hub half 17. If a
lock nut mechanism is used, a lock nut is simply tightened to prevent
reverse rotation after the upper hub half 17 is rotated relative to the
lower hub half 16 to a desired position.
Referring to FIG. 2, the blades 50 and 51 preferably include elongated
vanes 52 and 53, which slide beneath a plurality of the patient's ribs,
and recessed arcuate throats 54 and 55 that receive the patient's ribs
that are adjacent to the chest incision. The benefits of the recessed
throats 54 and 55 and the elongated vanes 52 and 53 will be discussed
below with regard to the operation of the access platform 10.
Blade arms 56 and 57 interconnect the blades 50 and 51 to the rest of the
access platform 10. The blade arms 56 and 57 comprise arm stems 62 and 63
received in sockets 34 and 35 in torque bases 32 and 33. The sockets 34
and 35 and the stems 62 and 63 are constructed such that the blade arms 56
and 57 are releasably connected to the torque bases 32 and 33. The stems
62 and 63, which extend relatively horizontally from the torque bases 32
and 33, include pivot sections 60 and 61 extending therefrom. Branches 58
and 59 extend outwardly and downwardly away from the pivot sections 60 and
61 and are attached to the throats 54 and 55 of the blades 50 and 51. This
blade arm construction advantageously directs the bulk of the access
platform 10 away from the surgeon's working area.
The support pads 80 and 81 are connected to adjustable arms 86 and 87 by
swivel connectors 82 and 83 that are preferably constructed as ball and
socket type connectors. The adjustable arms 86 and 87 preferably include
external shafts 88 and 89 slidably received over and operably connected to
internal shafts 98 and 99. The external shafts 88 and 89 are preferably
operably connected to the internal shafts 98 and 99 via a ratchet lever
mechanism (not shown). The internal shafts 98 and 99 of the adjustable
arms 86 and 87 are further connected to lock positioners 90 and 91. The
lock positioners 90 and 91, which are attached to the torque bases 32 and
33, comprise a ratchet or a wrap spring type mechanism (not shown) or,
alternatively, comprise opposing face gears 94 and 96, 95 and 97. Tabs 92
and 93 rotate and cooperate with cammed or serrated surfaces 36 and 37 on
the outer face of the outer face gears 94 and 95 to engage and disengage
the opposing face gears 96 and 97. Thus, when the tabs 92 and 93 are
rotated to disengage the face gears 94 and 96, 95 and 97, the support pads
80 and 81 can be rotated to a desired position. Once the support pads 80
and 81 are in position, the tabs 92 and 93 are rotated to engage the face
gears 94 and 96, 95 and 97 and, thus, lock the support pads 80 and 81 in
place.
The torsional members 30 and 31 are operably connected to the torque bases
32 and 33 and the spreader arms 18 and 19 to enable the access platform 10
to both laterally retract and vertically displace a patient's ribs R.
Thus, the torsional members 30 and 31 enable the access platform 10 to be
advantageously self-contained such that the force necessary to spread and
vertically displace a patient's ribs, and the force necessary to depress
the patient's sternum, is applied by the access platform 10 itself rather
than through additional external devices.
The torsional members 30 and 31 preferably comprise a reduction gear
assembly 40 (see FIG. 4). The reduction gear assembly 40 comprises a drive
nut 42 rotatably captured on the end of the shaft of the spreader arm 18
or 19, a first shaft 45 axially extending from the spreader arm 18 or 19,
and a second shaft 47 extending from the torque base 32 or 33. the second
shaft 47 is rotatably captured over the first shaft 45 by a shoulder screw
49.
The drive nut 42 preferably has a beveled face 43 that is adjacent to an
end of the second shaft 47. A wobble plate 44 mounted on the first shaft
45 interposes the drive nut 42 and the second shaft 47. The wobble plate
44 is captured in splines 46 on the first shaft 45 to prevent the wobble
plate 44 from rotating relative to the first shaft 45. The splines 46,
however, do not restrict the wobble plate's 44 wobble motion.
The wobble plate 44 and the second shaft 47 include opposing operably
connected face gears 41 and 48, respectively. The face gear 41 on the
wobble plate 44 only meshes fully at one point with the face gear 48 on
the second shaft 47 as the wobble plate 44 wobbles from the rotation of
the drive nut 42. Thus, the interaction between the face gears 41 and 48
creates a gear ratio between the drive nut 42 and the second shaft 47 that
is preferably in the range of about 60-80:1. Accordingly, only a
relatively low torque is necessary to turn the drive nut 42 to rotate the
second shaft 47, in either direction and, thus, rotate the torque base 32
and 33 with a torque necessary to vertically displace a patient's ribs
with blades 50 and 51 and to depress a patient's sternum with the support
pads 80 and 81.
Alternatively, the torsional members 30 and 31 could comprise a ratchet
mechanism, a wrap spring mechanism or a lock nut mechanism (not shown)
wherein a wrench or a special tool could be used to rotate the torque
bases 32 and 33 to a desired position. Once the torque bases 32 and 33 are
rotated to their desired positions, they are prevented from reverse
rotation by the ratchet mechanism, wrap spring mechanism or lock nut
mechanism.
Turning to FIGS. 5A-7, the tissue retractors 70 and 71 comprise arms 72A
and 72B extending from hubs 73A and 73B. The hubs 73A and 73B are
rotatably mounted on the pivots 60 and 61 of the blade arms 56 and 57. At
an end opposite to the hubs 73A and 73B, spindles 74A and 74B extend from
the arms 72A and 72B. Elastic sheets 77A and 77B, preferably constructed
from natural latex rubber, attach at one end to the spindles 74A and 74B,
and at the opposite end to attachment plates 78 and 79. Slots 68 and 69 in
the attachment plates 78 and 79 enable the attachment plates 78 and 79 to
connect to the blades 50 and 51 by communicating with hooks 64 and 65
extending from the blades 50 and 51. As shown in FIG. 5A, a locking pin 75
is attached in a parallel manner to the spindle 74B. The locking pin 75
communicates with a recess 76 in the arm 72B such that the spindle 742 can
be rotated to take up excess slack in the elastic sheet 77B and, then,
locked in place by mating the locking pin 75 with the recess 76. A locking
pin (not shown) is attached to the spindle 74A and a recess (not shown) is
formed in the arm 72A. Alternatively, the arms 72A and 72B would include a
plurality of recesses (not shown) for greater adjustability.
The tissue retractors 70 and 71 include a plurality of low profile button
cleats 7 formed in the top surface of the elastic sheets 77A and 77B. The
cleats 7 include a stem 8 that extends upwardly from the elastic sheets
77A and 77B and a cap 9 that attaches to the stem 8. In operation, the
surgeon can anchor sutures to the cleats 7 which the surgeon would
normally anchor to the patient's chest.
Alternatively, as shown in FIG. 5B, a tissue retractor 100 includes a
plurality of retractor fingers 101, 102 and 103 extending upwardly from
the throat section 55 of the blade 51. The retractor fingers are
preferably constructed from annealed sheet metal approximately 0.035 inch
thick. The fingers 101, 102 and 103 are preferably welded onto the blade
51 or 50.
Prior to operation, the retractor-fingers 101, 102 and 103 extend
relatively vertically from the blade 51 or 50. Once the blade 51 or 50 is
in position, the retractor fingers 101, 102 and 103 are bent over the
patient's rib cage to retract the soft tissue adjacent to the incision
area out of the surgeon's working space. Because of the thickness of the
sheet metal, the retractor fingers 101, 102 and 103 are easily deformed
and retain their position once deformed.
Referring to FIG. 1, the access platform 10 preferably includes a port 66
shown mounted on one of the blade arms 56 adjacent to the pivot 60. The
port 66 can be used to mount a heart stabilizer instrument 67 for which a
patent application has been filed. Additional ports located on the other
blade arm 57 adjacent the pivot 61 or located adjacent to the blades 50
and 51 on both blade arms 56 and 57, may be desirable to mount other
surgical instruments used in a "beating heart" CABG procedure, such as a
scope for IMA take down, an IMA holder used to hold the IMA during the
installation of the graft or a suture holder. The mounting of these
instruments to the access platform 10 advantageously eliminates the need
for an additional set of hands around the surgical site.
In operation, the blades 50 and 51 are positioned within the incision in
the patient's chest P such that the vanes 52 and 53 slide under the
patient's ribs R (see FIGS. 6 and 7). The throats 54 and 55 of the blades
50 and 51 receive and substantially surround opposing ribs adjacent to the
incision in the patient's chest P. Once the blades 50 and 51 are in
position, the blades 50 and 51 are connected to the rest of the access
platform 10 by inserting the stems 62 and 63 of the blade arms 56 and 57
into the sockets 34 and 35 in the torque bases 32 and 33.
Next, the hub 14 of the spreader member 12 is rotated to laterally spread
the spreader arms 18 and 19 apart until the blades 50 and 51 have
retracted the patient's ribs R to a desired spacing. The support pads 80
and 81 are then lowered to rest on the patient's chest and locked in place
with lock positioners 90 and 91. At this point, the torque bases 32 and 33
are rotated relative to the torsional members 30 and 31 to displace in an
essentially vertical direction the blades 50 and 51, and ultimately the
patient's ribs R, relative to each other.
As the blade 51 is raised, the corresponding support pad 81 depresses the
patient's sternum to further cause a greater deflection in the patient's
rib cage and, thus, increase the "tunnel" effect. The elongated vane
construction of the blades 50 and 51 advantageously enables the access
platform 10 to vertically raise a plurality of the patient's ribs R to
cause a greater "tunnel" effect under a patient's rib cage and, thus,
increases the surgeon's working area and visual access to the IMA. The
recessed throat construction of the blades 50 and 51 advantageously
enables the access platform 10 to vertically displace the opposite rib
that is adjacent to the chest incision downwardly to further increase the
surgeon's visual access. This combined motion helps to create an optimum
tunnel.
After the ribs have been offset, the tissue retractors 70 and 71 or 100 are
operated to retract the soft tissue T away from the incision area by
either rotating the arms 72A and 72B about the pivots 60 and 61 on the
blade arms 56 and 57 (See FIGS. 6 and 7) or bending the retractor fingers
101, 102 and 103 over the patient's chest. By rotating the arms 72A and
72B about the pivots 60 and 61, the elastic sheets 77A and 77B
advantageously grab, pull and press down against the soft tissue T
adjacent to the incision to retract it away from the incision and out of
the surgeon's working area. The over-center positioning of the arms 72A
and 72B about the hubs 73A and 73B, effectively locks the tissue
retractors 70 and 71 in place during use. By deforming the retractor
fingers 101, 102 and 103, the fingers are bent over the patient's rib cage
and advantageously pressed down against the soft tissue adjacent to the
incision to retract it away from the incision and out of the surgeon's
working area.
In a first offset position, the blade 51 raises the retracted ribs and the
blade 50 depresses the retracted ribs so that the surgeon can dissect the
proximal portion of the IMA. Next, the blades 50 and 51 are rotated to a
second offset position wherein the blade 50 raises the retracted ribs and
the blade 51 depresses the retracted ribs. In this offset position, the
surgeon takes down the distal portion of the IMA. With the dissection of
the IMA complete, the surgeon levels the blades 50 and 51 and then engages
the heart stabilizer 67. With the heart stabilizer 67 engaged to minimize
the movement of the heart, the surgeon performs an arteriotomy and an
anastomosis. After completion of the arteriotomy and anastomosis, the
surgeon removes the stabilizer 67, buttons up the pericardial sac,
disengages the soft tissue retractors 70 and 71 or 100, and brings the
blades 50 and 51 together. The blades 50 and 51 are then disengaged from
the access platform 10 and removed from the interior of the patient's
chest. With the blades 50 and 51 removed, the surgeon is able to sew up
the thoracotomy and complete the surgical procedure.
A second embodiment of the access platform 110 is shown in FIGS. 8, 9 and
10. The second embodiment of the access platform 110 includes a spreader
member 112 preferably comprising a horizontally disposed rack 120 and
pinion housings 121 and 122 slidably disposed over the rack 122 rotatably
retousings 121 and 122 rotatably retain pinions 123 and 124 driven by
levers 125 and 126.
Torsional members 130 and 131 preferably comprise curved racks 132 and 133
slidably received within pinion housings 134 and 135. The pinion housings
134 and 135 are fixedly attached to the pinion housings 122 and 121. The
pinion housings 134 and 135 rotatably retain pinions 136 and 137 driven by
levers 138 and 139. Sockets 154 and 155 are formed in the lower ends of
the curved racks 132 and 133. Stems 152 and 153 of blade arms 146 and 147
are releasably received by and horizontally extend from the sockets 154
and 155.
The blade arms 146 and 147 further comprise pivot sections 150 and 151
extending horizontally from the stems 152 and 153. Branches 148 and 149
extend downwardly and outwardly from the pivot sections 150 and 151 of the
blade arms 146 and 147 to position the remainder of the access platform
110 away from the surgeon's working area. Branches 148 and 149 attach to
blades 140 and 141. The blades 140 and 141 comprise elongated vane
sections 142 and 143 extending outwardly from recessed throat sections 144
and 145.
Preferably, one end of the horizontally disposed rack 120 is connected to a
slide 172 of a lock positioner 171. The slide 172 is slidably received
over a vertically disposed support pad stanchion 167. The stanchion 167
has ratchet gear teeth 173 formed thereon which cooperate with a ratchet
lever 174 attached to the slide 172 to adjustably position the support pad
161. The support pad 161 is adjustably connected to the stanchion 167 by a
swivel connector 163.
The opposing end of the horizontally disposed rack 120 is preferably
connected to a support pad link 176 via a lockable ball and socket joint
177. The support pad link 176 is further connected to a second support pad
link 175 via a hinge joint 178. This link and joint assembly allows for
the multiple positioning of the support pad 160. The support pad 160 is
further connected to the support pad link 175 via a swivel connector 162.
In addition, the access platform 110 includes a mount 156, attached to the
blade arm 147. The mount 156 enables the access platform 110 to hold a
heart stabilizer tool 67 shown in FIG. 1, an IMA holder, an IMA scope, a
suture holder, or other surgical instruments used in a "beating heart"
CABG procedure. Thus, the mount 156 advantageously eliminates the need for
an undesirable extra set of hands around the surgical site.
In operation, the blades 140 and 141 are inserted in an incision in the
patient's chest such that the blade vanes 142 and 143 slide under the
patient's ribs and the recessed throats 144 and 145 of the blades 140 and
141 receive the ribs that are adjacent to the incision. After the blades
140 and 141 are properly positioned, the stems 152 and 153 of the blade
arms 146 and 147 are inserted into the sockets 154 and 155 of the
torsional members 130 and 131 to connect the blades 140 and 141 to the
remainder of the access platform 110. The levers 126 and 125 are then
rotated to drive the pinions 121 and 122 over the rack 120 to laterally
retract the ribs. When a desired spacing between the retracted ribs is
met, the support pads 160 and 161 are positioned on the chest of the
patient, | | |
