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Claims  |
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What is claimed is:
1. A surgical access platform comprising a spreader member,
first and second blade interconnected to said spreader member, said first
and second blades being adapted to engage opposing sides of a chest
incision, with adjustment of said spreader member causing lateral
displacement of said first blade relative to said second blade, and
a displacement member operably interconnected to said first blade and said
spreader member, with adjustment of said displacement member causing
generally vertical bi-directional displacement of said first blade
relative to said second blade.
2. The surgical access platform of claim 1, further comprising a support
pad interconnected to said first blade.
3. The surgical access platform of claim 2, wherein said support pad is
adjustably interconnected to said first blade.
4. The surgical access platform of claim 1, further comprising a first
support pad and a second support pad interconnected to said first and
second blades respectively.
5. The surgical access platform of claim 1, wherein said spreader member
further comprises a hub.
6. The surgical access platform of claim 5, wherein said hub further
comprises an upper hub rotatably connected to a lower hub.
7. The surgical access platform of claim 5, wherein said hub further
comprises a ratchet mechanism operably interconnecting a first hub member
to a second hub member.
8. The surgical access platform of claim 5, wherein said hub further
comprises a harmonic gear assembly operably interconnecting a first hub
member to a second hub member.
9. The surgical access platform of claim 6, further comprising first and
second spreader arms extending from said upper and lower hubs
respectively.
10. The surgical access platform of claim 1, wherein said spreader member
further comprises a rack and pinion assembly.
11. The surgical access platform of claim 10, wherein said rack and pinion
assembly further comprises
a pinion housing slidably received over said rack and interconnected to
said first blade, and
a pinion wrench rotatably received in said pinion housing and operably
connected to said rack.
12. The surgical access platform of claim 1, wherein said first blade
further comprises an elongated vane.
13. The surgical access platform of claim 1, wherein said first blade
further comprises a recessed throat.
14. The surgical access platform of claim 1, wherein the displacement
member further comprises a first member operably connected to a second
member.
15. The surgical access platform of claim 14, wherein said first member
further comprises a reduction gear.
16. The surgical access platform of claim 14, wherein said first member
further comprises a ratchet mechanism.
17. The surgical access platform of claim 14, wherein said first and second
members further comprises a curved rack and pinion assembly.
18. The surgical access platform of claim 1, further comprising a tissue
retractor operably interconnected to said first blade.
19. The surgical access platform of claim 1, further comprising a blade arm
extending from said first blade and operably connected to said torsional
member.
20. The surgical access platform of claim 19, further comprising a tissue
retractor pivotally connected to said blade arm and connected to said
first blade.
21. The surgical access platform of claim 1 further comprising
first and second elongated stanchions coupled to said first and second
blades, respectively, and said spreader member, said first stanchion being
operably coupled to said displacement member, said first stanchion being
adjustable in a lateral direction relative to said second stanchion, said
first blade being displaceable in a generally vertical direction relative
to said second blade.
22. The access platform of claim 21, further comprising
first and second rotational members mounted adjacent the top of said first
and second stanchions, and
first and second blade arms extending outwardly from said first and second
rotational members and connecting to said first and second blades.
23. The surgical access platform of claim 1, further comprising a second
displacement member interconnected to said second blade and said spreader
member.
24. The surgical access platform of claim 1, further comprising
a blade arm connected to said second blade and interconnected to said
spreader member, and
a surgical instrument attached to said blade arm and extendable into the
chest cavity through a chest incision.
25. The surgical access platform of claim 24, wherein said surgical
instrument comprises a stabilizer, said stabilizer being positionable on a
beating heart.
26. A surgical access platform comprising a hub,
first and second blade interconnected to said hub, said first and second
blades being adapted to engage opposing incision edges of a chest
incision, with adjustment of said hub causing relative lateral
displacement between said first and said second blades, and
a torsional member operably interconnected to said first blade and said
hub, with adjustment of said torsional member causing generally vertical
bi-directional displacement of said first blade relative to said second
blade.
27. The surgical access platform of claim 26, further comprising a support
pad interconnected to said first blade.
28. The surgical access platform of claim 27 wherein said support pad is
adjustably interconnected to said first blade.
29. The surgical access platform of claim 26, further comprising a first
support pad and a second support pad interconnected to said first and
second blades respectively.
30. The surgical access platform of claim 26, wherein said hub further
comprises an upper hub rotatably connected to a lower hub.
31. The surgical access platform of claim 26, wherein said hub further
comprises a ratchet mechanism operably interconnecting a first hub member
to a second hub member.
32. The surgical access platform of claim 26, wherein said hub further
comprises a harmonic gear assembly operably interconnecting a first hub
member to a second hub member.
33. The surgical access platform of claim 30, further comprising first and
second spreader arms extending from said upper and lower hubs
respectively.
34. The surgical access platform of claim 26, wherein said first blade
further comprises an elongated vane.
35. The surgical access platform of claim 26, wherein said first blade
further comprises a recessed throat.
36. The surgical access platform of claim 26, wherein the torsional member
further comprises a first member operably connected to a second member.
37. The surgical access platform of claim 36, wherein said first member
further comprises a reduction gear.
38. The surgical access platform of claim 36, wherein said first member
further comprises a ratchet mechanism.
39. The surgical access platform of claim 26, further comprising a tissue
retractor operably interconnected to said first blade.
40. The surgical access platform of claim 26, further comprising a blade
arm extending from said first blade and operably connected to said
torsional member.
41. The surgical access platform of claim 40, further comprising a tissue
retractor pivotally connected to said blade arm and connected to said
first blade.
42. A method of thoracic surgery comprising the steps of
providing a surgical access platform, said platform comprising first and
second blades adapted to engage opposing sides of a chest incision, a
spreader member interconnected to said first and second blades, and a
displacement member operably interconnected to said first blade and said
spreader member, with adjustment of said displacement member causing
generally vertical bi-directional displacement of said first blade
relative to said second blade,
positioning said first and second blades in a chest incision to engage
opposing sides of the incision,
spreading said first blade relative to said second blade in a generally
lateral direction, and
displacing said first blade relative to said second blade in a generally
vertical direction to vertically offset opposing sides of the incision.
43. The method of thoracic surgery of claim 42, further comprising the
steps of
providing a support pad interconnected to said first blade,
positioning said support pad on the chest adjacent the sternum, and
depressing the sternum adjacent said support pad.
44. The method of thoracic surgery of claim 42, further comprising the
steps of
providing a second displacement member interconnected to said second blade
and said spreader member, and
displacing said second blade in a generally vertical direction opposite to
the displacement of said first blade.
45. The method of thoracic surgery of claim 42, further comprising the
steps of
providing a stabilizer interconnected to said second blade, and
positioning said stabilizer on a beating heart to stabilize said beating
heart. |
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Claims |
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Description |
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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.
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 is 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. 5 is an isometric view of a blade, a blade arm and a tissue retractor
assembly of the access platform shown in FIG. 1.
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. 13 is an isometric view of a fourth embodiment of the access platform
of the present invention.
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.
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 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
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
retracted ribs that are proximal 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 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 mounted on the first shaft 45
interposes the drive nut 42 and the second shaft 47. The wobble plat | | |
