U.S. patent application number 10/231955 was filed with the patent office on 2003-03-27 for access platform for internal mammary dissection.
Invention is credited to Aldrich, William N., Morejohn, Dwight P., Taylor, Charles S..
Application Number | 20030060686 10/231955 |
Document ID | / |
Family ID | 27416897 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030060686 |
Kind Code |
A1 |
Taylor, Charles S. ; et
al. |
March 27, 2003 |
Access platform for internal mammary dissection
Abstract
An access platform having a first and a second blade
interconnected to a spreader member that laterally drives the
blades apart or together and a sternal pad interconnected to a
blade. The superior blade is pivotally coupled to the spreader
member such that it naturally rises as the blades are separated.
Alternatively, a vertical displacement member is operably
interconnected to a blade and the spreader member and is used to
vertically displace the interconnected superior blade and, thus,
increase a surgeon's working space and visual access for the
dissection of an internal mammary artery. A tissue retractor is
interconnected to the blades to draw the soft tissue around an
incision away from the surgeon's working area.
Inventors: |
Taylor, Charles S.; (San
Francisco, CA) ; Aldrich, William N.; (Los Altos
Hills, CA) ; Morejohn, Dwight P.; (Davis,
CA) |
Correspondence
Address: |
BOZICEVIC, FIELD & FRANCIS LLP
200 MIDDLEFIELD RD
SUITE 200
MENLO PARK
CA
94025
US
|
Family ID: |
27416897 |
Appl. No.: |
10/231955 |
Filed: |
August 30, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10231955 |
Aug 30, 2002 |
|
|
|
09378292 |
Aug 20, 1999 |
|
|
|
6478734 |
|
|
|
|
09378292 |
Aug 20, 1999 |
|
|
|
08903516 |
Jul 30, 1997 |
|
|
|
5944736 |
|
|
|
|
08903516 |
Jul 30, 1997 |
|
|
|
08787748 |
Jan 27, 1997 |
|
|
|
08787748 |
Jan 27, 1997 |
|
|
|
08619903 |
Mar 20, 1996 |
|
|
|
5976171 |
|
|
|
|
08619903 |
Mar 20, 1996 |
|
|
|
08604161 |
Feb 20, 1996 |
|
|
|
5730757 |
|
|
|
|
Current U.S.
Class: |
600/210 |
Current CPC
Class: |
A61B 17/025 20130101;
A61B 17/3423 20130101; A61B 17/0206 20130101; A61B 90/50 20160201;
A61B 2017/349 20130101; A61B 17/3476 20130101 |
Class at
Publication: |
600/210 |
International
Class: |
A61B 001/32 |
Claims
What is claimed is:
1. A tissue retractor comprising a positioner mountable to a
retractor blade, a plurality of interconnected fingers rotatably
coupled to said positioner, said plurality of interconnected
fingers being freely rotatable in a first direction and prevented
from rotating in a second direction by said positioner.
2. The tissue retractor of claim 1 wherein said positioner
comprises an elongated base, a guide attaching to said base and
extending along said base, a brake radially extending from said
guide and extending along said base, and a sleeve interconnected to
said plurality of interconnected fingers, said sleeve being
rotatably mounted over said guide and said brake.
3. The tissue retractor of claim 2, wherein said positioner further
comprises a flexure connecting said guide to said brake.
4. The tissue retractor of claim 3, wherein said guide comprises a
central portion integrally formed with said base and outer portions
formed in a spaced relation with said base, and a tab extending
upwardly from said brake adjacent said central portion of said
guide.
5. The tissue retractor of claim 2, wherein said brake is generally
pie-shaped and includes a radius that is sized to direct said brake
into contact with said sleeve to inhibit the rotation of said
sleeve in the second direction.
6. The tissue retractor of claim 1, wherein said plurality of
interconnect fingers are deformable.
7. A tissue retractor comprising a hub, an arm extending from said
hub, and an elastic sheet interconnected to said arm.
8. The tissue retractor of claim 7, further comprising a spindle
extending from said arm and connected to said sheet.
9. The tissue retractor of claim 8, further comprising a locking
pin operable connected to said spindle and said arm.
10. The tissue retractor of claim 7 further comprising a suture
cleat attached to said elastic sheet.
11. A tissue retractor comprising a flexible ring adapted to extend
around an incision in a patient's body, and an elastic sheet
attachable at a first end to a retractor blade and at a second end
to said ring.
12. A tissue retractor comprising a base attachable to a spreader
blade, and a plurality of deformable fingers extending from said
base.
13. A tissue retractor comprising a spreader blade, and a tissue
retaining member formed integrally with said blade and extending
therefrom.
Description
[0001] This application is a continuation of co-pending application
Ser. No. 08/903,516, filed on Jul. 30, 1997, now allowed, which in
turn is a continuation of application Ser. No. 08/787,748, filed on
Jan. 27, 1997, now abandoned, which in turn is a
continuation-in-part of co-pending application Ser. No. 08/619,903,
filed on Mar. 20, 1996, now allowed, which in turn is a
continuation-in-part of application Ser. No. 08/604,161, filed on
Feb. 20, 1996, now issued as U.S. Pat. No. 5,730,757, the
disclosures of which are incorporated herein by reference as if set
forth in full.
DESCRIPTION
[0002] 1. Field of the Invention
[0003] 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.
[0004] 2. Background of the Invention
[0005] 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.
[0006] 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.
[0007] The CABG procedure further requires that a connection for
the flow of blood be established between two points that "bypass" 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."
[0008] 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."
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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
[0018] 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 first and second
blades interconnected to a spreader member that laterally drives
the blades apart or together, a sternal pad interconnected to the
blades, and a vertical displacement member interconnected to a
blade and the spreader member. The vertical displacement member may
preferably be bi-directional to cause the interconnected blade to
be vertically displaced in either direction and, thus, increases
the surgeon's working space and visual access to the IMA.
[0019] 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.
[0020] In other embodiments, the superior blade is preferably
pivotally mounted to the spreader member at a pivot point above the
blade. The superior blade is naturally lifted as a spreading force
from the inferior blade is transmitted to the superior blade
through the pivot. The sternal pad may preferably be rotatably
coupled to the superior blades.
[0021] In further embodiments, bladeless embodiments comprising
tubular or hollow conically shaped bodies provide access to a
patient's chest cavity.
[0022] It is an object of the present invention to provide an
improved access platform.
[0023] Another object of the present invention is to provide an
improved tissue retractor.
[0024] 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
[0025] FIG. 1 is a top view of an embodiment of an access platform
of the present invention disposed over the chest of a patient.
[0026] FIG. 2 is an isometric view of the access platform shown in
FIG. 1 less the tissue retractor elements.
[0027] FIG. 3 is an exploded isometric view of a harmonic gear
drive assembly of the access platform in FIG. 1.
[0028] FIG. 4 is a cross-sectional view of a reduction gear
assembly in the torsional element of the access platform taken
along line 4-4 in FIG. 1.
[0029] FIG. 5 is an isometric view of a blade, a blade arm and a
tissue retractor assembly for an access platform.
[0030] FIG. 6 is a front view of the access platform with the
tissue retractors disengaged.
[0031] FIG. 7 is a front view of the access platform with the
tissue retractors engaged.
[0032] FIG. 8 is a partial isometric view of a tissue retractor and
blades assembly for an access platform.
[0033] FIG. 9 is an isometric view of a tissue retractor assembly
for an access platform.
[0034] FIG. 10 is a side view of the tissue retractor assembly
shown in FIG. 7 and including a positioning assembly.
[0035] FIG. 11 is an isometric view of the tissue retractor and
positioning assembly in FIG. 8.
[0036] FIG. 12 is a partial side detail view of the positioning
assembly in FIG. 8.
[0037] FIG. 13 is a top view of a second embodiment of the access
platform of the present invention.
[0038] FIG. 14 is a partial front view of the access platform in
FIG. 13.
[0039] FIG. 15 is a side view of the access platform as viewed
along a line 15-15 in FIG. 13.
[0040] FIG. 16 is a front view of a third embodiment of the access
platform of the present invention.
[0041] FIG. 17 is a front view of the access platform shown in FIG.
16 with a vertical displacement member engaged.
[0042] FIG. 18 is an isometric view of a fourth embodiment of the
access platform of the present invention.
[0043] FIG. 19 is an isometric view of a fifth embodiment of the
access platform of the present invention.
[0044] FIG. 20 is an elevation view of a pry bar for engaging the
blade and blade arm of the access platform in FIG. 18.
[0045] FIG. 21 is a top view of the pry bar in FIG. 20.
[0046] FIG. 22 is an isometric view of a sixth embodiment of the
access platform of the present invention.
[0047] FIG. 23 is an isometric view of a seventh embodiment of the
access platform of the present invention.
[0048] FIG. 24 is a top view of an eighth embodiment of the access
platform of the present invention.
[0049] FIG. 25 is a rear view of the access platform in FIG.
24.
[0050] FIG. 26 is an isometric view of a ninth embodiment of the
access platform of the present invention.
[0051] FIG. 27 is a front elevation view of a tenth embodiment of
the access platform of the present invention.
[0052] FIG. 28 is an isometric view of an eleventh embodiment of
the access platform of the present invention.
[0053] FIG. 29 is an isometric view of a twelfth embodiment of the
access platform of the present invention.
[0054] FIG. 30 is an isometric view of a thirteenth embodiment of
the access platform of the present invention.
[0055] FIG. 31 is a top view of a fourteenth embodiment of the
access platform of the present invention.
[0056] FIG. 32 is a partial front elevation view of the access
platform in FIG. 31.
[0057] FIG. 33 is an isometric view of a fifteenth embodiment of
the access platform of the present invention.
[0058] FIG. 34 is a partial front elevation view of the access
platform in FIG. 33.
[0059] FIG. 35 is a top view of a spreader member drive assembly of
the access platform in FIG. 33.
[0060] FIG. 36 is an isometric view of a clutch assembly of the
drive assembly in FIG. 35.
[0061] FIG. 37 is a partial cross-sectional view of the clutch
assembly in FIG. 36.
[0062] FIG. 38 is a partial top schematic of the clutch assembly in
FIG. 36.
[0063] FIG. 39 is an isometric view of an sixteenth embodiment of
the access platform of the present invention.
[0064] FIG. 40 is an isometric view of a seventeenth embodiment of
the access platform of the present invention.
[0065] FIG. 41 is an isometric view of a eighteenth embodiment of
the access platform of the present invention.
[0066] FIG. 42 is a front elevation view of the access platform in
FIG. 41 in a pre-spreading closed mode positioned between a
patient's ribs.
[0067] FIG. 43 is a front elevation view of the access platform in
FIG. 41 in an open mode positioned between a patient's ribs.
[0068] FIG. 44 is an isometric view of a removable offset spreader
assembly utilized with the access platform in FIG. 41.
[0069] FIG. 45 is an isometric view of an offset positioning
assembly utilized with the access platform in FIG. 41.
[0070] FIG. 46 is an isometric view of the access platform in FIG.
41 with the offset spreader assembly in FIG. 44 removed and the
offset positioning assembly in FIG. 45 attached.
[0071] FIG. 47 is a front elevation view of the access platform in
FIG. 46 in an engaged position maintaining the lift and separation
of a patient's ribs.
[0072] FIG. 48 is an isometric view of a nineteenth embodiment of
an access platform of the present invention.
[0073] FIG. 49 is an isometric view of a twentieth embodiment of
the access platform of the present invention positioned between a
patient's ribs.
[0074] FIG. 50 is a partial sectional isometric view of the access
platform in FIG. 49.
[0075] FIG. 51 is an isometric view of the access platform in FIG.
49 rotated to access the IMA.
[0076] FIG. 52 is a partial sectional isometric view of the access
platform in FIG. 51.
[0077] FIG. 53 is an elevation view of a twenty-first embodiment of
the access platform of the present invention entering a patient's
chest cavity.
[0078] FIG. 54 is an elevation view of the access platform in FIG.
53 in an intermediately engaged position.
[0079] FIG. 55 is an isometric view of the access platform in FIG.
53 in a final engaged position.
[0080] FIG. 56 is a top view of a locking assembly of the access
platform in FIG. 53.
[0081] FIG. 57 is an isometric view of a spreader member drive
assembly.
[0082] FIG. 58 is a partial detail elevation view of a drive gear
assembly for the drive assembly in FIG. 57.
[0083] FIG. 59 is a partial detail elevation view of a drive gear
assembly for the drive assembly shown in FIG. 57.
[0084] FIG. 60 is a top view of an access platform combining the
access platform embodiment in FIG. 19 with the drive gear assembly
in FIG. 3.
[0085] FIG. 61 is a top view of the access platform in FIG. 60
incorporating an alternate spreader member drive assembly.
[0086] FIG. 62 is a top view of a spreader member drive assembly
for an access platform.
[0087] FIG. 63 is a top view of a spreader member drive assembly
for an access platform.
[0088] FIG. 64 is a top view of a spreader member drive assembly
for an access platform.
[0089] FIG. 65 is a top view of a spreader member drive assembly
for an access platform.
[0090] FIG. 66 is a top view of a self-aligning blade embodiment of
the access platform of the present invention in a disengaged
position.
[0091] FIG. 67 is a top view of the access platform in FIG. 66 in
an engaged position.
[0092] FIG. 68 is a partial isometric view of a blade and blade arm
assembly of the access platform in FIG. 66.
[0093] FIG. 69 is a top view of opposing self-aligning blade and
blade arm assemblies.
[0094] FIG. 70 is a partial isometric view of one of the
self-aligning blade and blade arm assemblies in FIG. 69.
[0095] FIG. 71 is an isometric view of a spreader blade with a
foldable vane for offset.
[0096] FIG. 72 is an isometric view of a spreader blade with a
extensible vane for offset or tissue retraction.
[0097] FIG. 73 is an elevation view of a spreader blade and
detachable offset blade assembly.
[0098] FIG. 74 is an elevation view of the spreader blade and vane
assembly in FIG. 73 in a disengaged position.
[0099] FIG. 75 is an isometric view of a retractor blade with
detachable flexible edges.
[0100] FIG. 76 is an isometric view of a retractor blade with an
integral tissue retractor.
[0101] FIG. 77 is an isometric view of a spreader blade with
surgical tools mounted through access mounts formed integrally with
the spreader blade.
[0102] FIG. 78 is an isometric view of a spreader blade with
surgical tools mounted through access mounts formed integrally with
the spreader blade.
[0103] FIG. 79 is a cross-sectional view of the spreader blade and
flexible blower assembly in FIG. 77.
[0104] FIG. 80 is an isometric view of the access platform in FIG.
23 less the offsetting assembly and having a surgical clip mounted
thereto.
[0105] FIG. 81 is an isometric exploded view of a surgical clip,
mount and intermediate mounting block assembly.
[0106] FIG. 82 is an isometric view of the access platform in FIG.
35 having a mirror, a light source and clip assembly mounted
thereto.
[0107] FIG. 83 is a partial isometric view of an access platform in
an engaged position with the superior blade having a light panel
mounted thereto.
[0108] FIG. 84 is a partial elevation view of a directional light
source mounted to the bottom of a superior blade.
[0109] FIG. 85 is an isometric view of a spreader blade
assembly.
[0110] FIG. 86 is an isometric view of a spreader blade
assembly.
[0111] FIG. 87 is an isometric view of an access platform and
suture holder assembly.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0112] Referring now in detail to the drawings, therein illustrated
are novel embodiments of an 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. The
drawings illustrate various embodiments that at times incorporate
some of the same or similar structures. Thus, where the same or
similar structure appears in several drawings, and when practical,
the structure is labeled using the same reference numeral on each
drawing.
[0113] 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.
[0114] 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 hub halves
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.
[0115] 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 to spread
the spreader arms 18 and 19 and a patient's ribs apart.
[0116] 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 and spreader arm 19 are rotated to
a desired position relative to the lower hub half 16 and spreader
arm 18, 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. Other alternatives, such as lead-screw
mechanism or worm gear mechanism, are discussed in detail
below.
[0117] 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.
[0118] 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 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.
[0119] 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 84 and 85. 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 94 and 96, 95 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.
[0120] 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. 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.
[0121] The torsional members 30 and 31 preferably comprise a
reduction gear assembly 40 (see FIG. 4). The reduction gear
assembly 40, as shown for torsional member 31, comprises a drive
nut 42 rotatably captured on the end of the shaft of the spreader
arm 19, a first shaft 45 axially extending from the spreader arm
19, and a second shaft 47 extending from the torque base 33. The
second shaft 47 is rotatably captured over the first shaft 45 by a
shoulder screw 49.
[0122] 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.
[0123] 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.
[0124] 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,
wrap spring or lock nut mechanisms.
[0125] Turning to FIGS. 5-7, the tissue retractors 70 and 71
comprise arms 72A and 72B extending from hubs 73A and 73B,
respectively. 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. 5, 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 74B 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 similarly attached to the spindle 74A and a
recess (not shown) is similarly formed in the arm 72A.
Alternatively, the arms 72A and 72B would include a plurality of
recesses (not shown) for greater adjustability.
[0126] 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 instead of anchoring the sutures to the
patient's chest as is typically the case.
[0127] Turning to FIG. 8, the elastic sheets 77A and 77B of the
tissue retractors 70 and 71 are alternatively attached to a
multi-purpose flexible ring 113. The blades 50 and 51 are shown
extending into an incision in the patient's chest from blade arms
56 and 57. The flexible ring 113 conforms to the contours of a
patient's chest while outlining the surgeon's working space. The
flexible ring 113 holds the elastic sheets 77A and 77B in an
engaged position to retract tissue away from the working space. As
a multi-purpose ring, the flexible ring 113 could be used as a base
to mount surgical tools or hold sutures.
[0128] As shown in FIG. 9, a tissue retractor 100 alternatively
includes a plurality of malleable retractor fingers 101A, 101B and
101C 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 101A, 101B
and 101C are preferably welded onto the blades 51 or 50.
[0129] Prior to operation, the retractor fingers 101A, 101B and
101C extend relatively vertically from the blade 51 or 50. Once the
blade 51 or 50 is in position, the retractor fingers 101A, 101B and
101C 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 101A, 101B and 101C are easily deformed and retain their
position once deformed.
[0130] Turning to FIGS. 10, 11 and 12, the tissue retractor 100
optionally includes a positioner assembly 103. The positioner
assembly 103 includes a retractor base 104 mounted to the blade 51
by mounting pins 114. A semi-cylindrical guide 107 extends the
length of the retractor base 104. The central portion 109 of the
guide 107 is formed integrally with the retractor base 104. The
outer portions of the guide 107, however, are formed in a spaced
apart relation with the retractor base 104 and extend outwardly
from the central portion 109 of the guide 107. A generally
wedge-shaped brake 108 also extends the length of the retractor
base 104. The brake 108 is formed integrally with the guide 107
extending radially away from the guide at a narrowly formed flexure
106 which extends the length of the brake 108 and guide 107. A tab
105 located adjacent to the central portion 109 of guide 107
extends vertically from the brake 108.
[0131] A pair of sleeves 102A and 102B are rotatably received over
the guide 107 and brake 108. The sleeves 102A and 102B are
connected to or formed integrally with the retractor fingers 101A
and 101C, respectively. The retractor fingers 101A and 101C are
formed integrally with or are attached to a central retractor
finger 101B. The brake 108 includes a radius 111 extending
downwardly from the flexure 106. As the brake is rotated in the
counterclockwise direction, the radius 111 exceeds the radius of
the sleeves 102A and 102B.
[0132] In operation, pressure is applied to the fingers 101A, 101B
and 101C of the tissue retractor 100 to rotate the fingers 101A,
101B, and 101C in a clockwise rotation about the positioner
assembly 103 until the fingers 101A, 101B and 101C press against
the tissue adjacent to the surgeon's working space. Clockwise
rotation of the sleeves 102A and 102B causes the brake 108 to flex
about flexure 106 and rotate in the clockwise direction and thus
allow the sleeves to freely rotate about the guide 107 and the
brake 108. However, counterclockwise rotation of the sleeves 102A
and 102B is prevented by the brake 108. As the brake 108 rotates in
a counterclockwise rotation about flexure 106, the radius 111 of
the brake 108 will force the brake 108 into contact with the
sleeves 102A and 102B, and thus prevent rotation of the sleeves
102A and 102B in the counterclockwise direction. To release the
tissue retractor 100 from an engaged position, force is applied to
the tab 105 to cause the brake 108 to rotate in the clockwise
direction and flex about the flexure 106. By rotating in the
clockwise direction, the brake 108 is drawn away from the sleeves
102A and 102B, and thus, the sleeves 102A and 102B are able to
freely rotate about the positioner 103 in a counterclockwise
direction. As will be readily apparent to those skilled in the art
from the discussion herein, the tissue retractors described in
regard to FIGS. 5-12 are adaptable for use with any of the
embodiments of the access platform discussed herein.
[0133] 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 (shown more clearly in FIG. 2). 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.
[0134] In operation, the blades 50 and 51 are positioned within the
incision in the patient's chest 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. 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 (see FIG. 2) of the blade arms 56 and 57 into the
sockets 34 and 35 in the torque bases 32 and 33.
[0135] 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.
[0136] As the blade 51 is raised, the corresponding support pad 81
depresses the patient's sternum to 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.
[0137] 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. 5-7) or
bending or rotating the retractor fingers 101A, 101B and 101C (see
FIGS. 9-12) 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
or displacing the retractor fingers 101A, 101B and 101C, the
fingers advantageously press down against the soft tissue adjacent
to the incision to retract it away from the incision and out of the
surgeon's working area.
[0138] 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 (See FIG. 1). 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, 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.
[0139] A second embodiment of the access platform 110 is shown in
FIGS. 13, 14 and 15. 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 120. The pinion housings 121 and
122 rotatably retain pinions 123 and 124 driven by levers 125 and
126.
[0140] Vertical displacement 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.
[0141] 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.
[0142] 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 pawl 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.
[0143] 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.
[0144] 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.
[0145] 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 capture 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 vertical displacement members
130 and 131 to connect the blades 140 and 141 to the remainder of
the access platform 110. The levers 125 and 126 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, with support pad 160 being preferably positioned on
the patient's sternum. The levers 138 and 139 are then rotated to
drive the pinions 136 and 137 to draw the curved racks 132 and 133
through the pinion housing 134 and 135 to vertically displace the
blades 140 and 141 and the retracted ribs. As the blade 140 is
retracted upwards the support pad 160 preferably depresses the
sternum creating a greater deflection in the patient's rib cage
and, thus, creating a greater "tunnel" effect underneath the
patient's rib cage, to increase the surgeon's working space and
visual access for dissection of the IMA.
[0146] As in the first embodiment, after the ribs have been
vertically displaced, tissue retractors 70, 71 or 100 (shown in
FIGS. 5-12) are operated to retract the soft tissue away from the
incision area by either rotating the arms 72A and 72B about the
pivots 150 and 151 on the blade arms 146 and 147 or bending or
displacing the fingers 101A, 101B, and 101C over the patient's
chest. By rotating the arms 72A and 72B about the pivots 150 and
151, the elastic sheets 77A and 77B advantageously grab, pull, and
press down against the soft tissue to retract it away from the
incision and out of the surgeon's working area. By bending or
displacing the retractor fingers 101A, 101B and 101C over the
patient's chest the fingers 101A, 101B and 101C advantageously
press down against the soft tissue to retract it away from the
incision and out of the surgeon's working area.
[0147] In a first offset position, the blade 141 raises the
retracted ribs and the blade 140 depresses the retracted ribs so
that the surgeon can dissect the proximal portion of the IMA. Next,
the blades 140 and 141 are adjusted to a second offset position
wherein the blade 140 lifts the retracted ribs and the blade 141
depresses the retracted ribs. In the second offset position, the
surgeon takes down the distal portion of the IMA. With the
dissection of the IMA complete, the surgeon levels the blades 140
and 141 and then engages the heart stabilizer 67 shown in FIG. 1.
With the heart stabilizer 67 engaged to minimize the movement of
the heart, the surgeon performs an arteriotomy and anastomosis.
After completion of the arteriotomy and anastomosis, the surgeon
removes the stabilizer 67, disengages the soft tissue retractors 70
and 71 and brings the blades 140 and 141 together. The blades 140
and 141 are then disengaged from the access platform 110 and then
removed from the interior of the patient's chest. With the blades
140 and 141 removed, the surgeon is able to sew up the thoracotomy
and complete the surgical procedure.
[0148] A third embodiment of the access platform 210 is shown in
FIGS. 16 and 17. The third embodiment of the access platform 210
includes a spreader member 212 comprising a horizontally-disposed
rack 214 and pinion housings 216 and 218 slidably disposed over the
rack 214. Pinions 220 and 222 are rotatably retained in the pinion
housings 216 and 218 and driven by levers 224 and 226.
[0149] Blades 230 and 231 comprise elongated vane sections 232 and
233 extending from recessed throat sections 234 and 235. Blade arms
236 and 237 have branches 238 and 239 that extend downwardly and
outwardly from horizontally disposed stems 240 and 241 and connect
to the blades 230 and 231. The stems 240 and 241 of the blade arms
236 and 237 are releasably received in sockets 217 and 219 formed
in the pinion housings 216 and 218.
[0150] A vertical displacement member 250 comprises a support pad
252 that pivotally connects to the pinion housing 216 at a pivot
254 and extends laterally away from the pinion housing 216. An
"L"-shaped lever 256 is pivotally connected to the rack 214 at a
pivot 258 at the end of the short leg of the "L"-shaped lever 256.
A slide 259 is formed at the intersection of the short and long
legs of the "L"-shaped lever 256. The slide 259 slidably contacts
the support pad 252.
[0151] In operation, the blades 230 and 231 are inserted into the
chest incision and positioned such that the vane sections 232 and
233 slide under the patient's ribs R and the recess throat sections
234 and 235 capture the patient's ribs R adjacent to the incision.
Once the blades 230 and 231 are properly in place, the stems 240
and 241 of the blade arms 236 and 237 are inserted into the sockets
217 and 219 of the pinion housings 216 and 218. Next, the levers
224 and 226 are rotated to drive pinions 220 and 222 along the rack
214 to laterally retract the ribs. The "L"-shaped lever 256 is then
rotated downwardly in a counterclockwise direction toward the
patient's chest such that the slide portion 259 slides along the
support pad 252 toward the housing 220 while the "L"-shaped lever
256 rotates about the pivot 258. As a result, one end of the rack
214 is raised to vertically offset blade 230 and ribs R relative to
the blade 231 and ribs R.
[0152] As with the first two embodiments, the tissue retractors 70,
71 or 100 can be used with this embodiment of the access platform
210 to retract soft tissue away from the incision and the surgeon's
working area.
[0153] A fourth embodiment is shown in FIG. 18. The access platform
310 of the fourth embodiment includes a spreader member 312
comprising a rack 320, a housing 322 slidably received over the
rack 320, a pinion 324 rotatably retained in the housing 322 and a
lever 326 connected to the pinion 324. A spreader base 328 is
attached to one end of the rack 320. A pair of parallel spaced
fingers 330A and 330B extend from the housing 322. Similarly, a
pair of parallel spaced fingers 332A and 332B extend from the
spreader base 328 and are positioned parallel to the fingers 330A
and 330B extending from the housing 322.
[0154] A pair of blade arms 338 and 340 include branch sections 346
and 348 that extend downwardly from central portions 339 and 341
and connect to blades 350 and 352. Stem portions 342 and 344 extend
from the central portions 339 and 341 opposite the branch sections
346 and 348. The stem 342 extends between and is pivotally mounted
to fingers 330A and 330B at a pivot 331. Likewise, stem 344 extends
between and is pivotally mounted to fingers 332A and 332B at a
pivot 333. As a result, the blade arms 338 and 340 rotate about an
axis of rotation A.sub.1 that is parallel to the rack 320. This
construction advantageously enables the access platform 310 to
address a thoracotomy positioned anywhere along the chest wall
without intruding on the surgeon's working space. If the
thoracotomy is located on the lateral side of the chest wall the
spreader member 312, the spreader base 328 and the housing 322 are
simply pivoted away from the surgeon's working space.
[0155] If desired, locking pins 334 and 336 can be used to
immobilize the blade arms 338 and 340 and fix them relative to the
housing 322 and the spreader base 328.
[0156] As shown in FIG. 19, a fifth embodiment of the access
platform 310 modifies the fourth embodiment shown in FIG. 18 to
include a pair of links 360 and 362 interposed and hingedly
interconnected to the blade arms 338 and 340 and the housing 322
and spreader base 328, respectively. The links 360 and 362 comprise
link bodies 364 and 366 and parallel spaced fingers 368A and 368B
and 369A and 369B, respectively, extending from the link bodies 364
and 366. The link bodies 364 and 366 extend between and pivotally
mount to the fingers 330A and 330B and 332A and 332B at pivots 331
and 333, respectively. Likewise, the stems 342 and 344 of the blade
arms 338 and 340 extend between and pivotally mount to the fingers
368A and 368B and 369A and 369B at pivots 363 and 365,
respectively. As a result, the blade arms 338 and 340 and the links
360 and 362 rotate about parallel axes of rotation A.sub.1 and
A.sub.2 that are parallel to the rack 320. This construction
further enables the access platform 310 to address a thoracotomy
positioned anywhere along the chest wall without intruding on the
surgeon's working space by easily pivoting the spreader base 328,
the housing 332 and the rack 320 out of the surgeon's way.
[0157] Ports 354 and 356 are included on the blade arms 338 and 340
to mount 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 ports 354 and 356
advantageously eliminate the need for an undesirable extra set of
hands around the surgical site.
[0158] Turning to FIGS. 20 and 21, a pry bar 370, which is used in
conjunction with the access platform 310 shown in FIG. 18 or 19 to
offset a patient's ribs, comprises a generally "S"-shaped body 372
pivotally connected to a pivot base 377 at pivot 378. The pivot
base 377 is in turn pivotally connected to a blade arm 382 at pivot
380. The blade arm 382 extends downwardly from the pivot 380 and
connects to a blade 384. The blade 384 includes an elongated vane
386 and a deep recessed throat 388. A sternal pad 374 is connected
to a post 379 that is slidably mounted on the lower portion 373 of
the "S"-shaped body 372 via a slide 376.
[0159] In operation, the blade 384 is positioned such that the
throat 388 captures the blade 350 or 352 of the access platform
310. As the throat 388 captures the blade 350 or 352 the elongated
vane 386 extends under a plurality of the patient's ribs to be
offset. The pivot base 377 and the pivots 378 and 380 enable the
pry bar 370 to be adjustably positioned about two different axes of
rotation.
[0160] Once the blade 384 is positioned, the sternal pad 374 is
adjustably located to atraumatically conform the pry bar 370 to the
anatomy of the patient. Once the sternal pad 374 is in position, a
handle 375, in the upper portion of the "S"-shaped body 372, is
pulled to pivot the pry bar 370 about the sternal pad 374 and lift
the blade 384 and the blade 350 or 352 of the access platform 310
to offset the patient's ribs and create a "tunnel" to increase the
surgeon's working space and visual access for the dissection of the
IMA.
[0161] A sixth embodiment of the access platform 310 is shown in
FIG. 22 to comprise a combination of components from the first and
fourth embodiments (FIGS. 2 and 18). More particularly, the
torsional members 30 and 31 of the first embodiment are interposed
between and operably connected to the fingers 330A and 330B and the
housing 322, and interposed between and operably connected to the
fingers 332A and 332B and the spreader base 328, respectively. In
addition, the support pads 80 and 81 of the first embodiment are
adjustably attached to the fingers 330A and 330B, 332A and 332B. By
including the torsional members 30 and 31 and the support pads 80
and 81, second and third axes of rotation A.sub.2 and A.sub.3 are
provided. Thus, as in the first embodiment, the torsional members
30 and 31 enable the access platform 310 to vertically displace the
blades 350 and 352 and the retracted ribs. To vertically displace
the blades 350 and 352, the blade arms 338 and 340 are fixedly
coupled to the fingers 330A and 330B, 332A and 332B by pins 334 and
336.
[0162] Turning to FIG. 23, a seventh embodiment of the access
platform is shown to comprise a modification of the fifth
embodiment of the access platform shown in FIG. 19. The access
platform 310 in FIG. 23 includes an offset assembly 308
interconnected to the blades 350 and 352. The offset assembly 308
comprises lead screws 313 and 314 extending between the blades 350
and 352 and further operably interconnecting the blades 350 and
352. At a first end, the lead screws 313 and 314 are rotatably
captured by capture mounts 317 and 318. The capture mounts 317 and
318 are fixed to the blade 350. The threaded portion of the lead
screws 313 and 314 threadably passes through a pair of lift mounts
315 and 316. The lift mount 315 is affixed to the blade arm 340
which is interconnected to the superior blade 352. The lift mount
316 is affixed to the top of a lift mount arm 319 extending
vertically from the superior blade 352 to a height which is level
with the lift mount 315 on the blade arm 340. Levers 309 and 311,
which are attached to a second end of the lead screws 313 and 314,
are used to rotate the lead screws 313 and 314 to drive the lift
mounts 315 and 316 thereon. With the horizontal distance between
the inferior and superior blades 350 and 352 adjustably fixed by
the spreader member 312, the offset assembly 308 is only able to
vertically displace the blade 352 relative to the blade 350. Thus,
depending on the direction of rotation of the lead screws 313 and
314, the superior blade 352 will be raised or lowered to offset it
relative to the inferior blade 350.
[0163] Referring to FIGS. 24 and 25, an eighth embodiment of the
access platform of the present invention includes telescoping arms
390 and 392 incorporated with the access platform 310 shown in FIG.
18. The telescoping arms 390 and 392 are perpendicularly disposed
between and releasably attached to the blades 350 and 352. In
addition, the blade arms 338 and 340 include branch extensions 347
and 349 releasably coupled at break lines B.sub.1 and B.sub.2 to
the branches 346 and 348 (FIG. 25).
[0164] In operation, the blades 350 and 352 are inserted in an
incision in the chest to capture the ribs. The lever 326 is then
rotated to drive pinion 324 along the rack 320 and spread the ribs.
Once the ribs are retracted to a desired spacing, the telescoping
arms 390 and 392 are connected to the blades 350 and 352 and
engaged to hold the blades 350 and 352 apart. The branches 346 and
348 are then decoupled from the branch extensions 347 and 349. The
remainder of the access platform 310 can be moved away from the
surgical site to give the surgeon additional space to work.
[0165] Also included with the fourth, fifth, sixth, seventh and
eighth embodiments (FIGS. 18, 19, 22, 23 and 24-25, respectively)
of the access platform 310, are ports or mounts (not shown) similar
to the port 66 shown in FIG. 1 and similarly used to mount a heart
stabilizer 67 (FIG. 1), an IMA holder, an IMA scope, a suture
holder or other surgical instruments used in a "beating heart" CABG
procedure. The surgical instrument mounting capability of the
access platform advantageously tends to eliminate the need for
extra sets of hands around the surgical area.
[0166] Turning to FIG. 26, a ninth embodiment of the access
platform 410 of the present invention is shown. The access platform
410 mounts to the table or rail via slides 438 and 440 that are
locked in place by positioners 450 and 452. The slides 438 and 440
rotatably retain pinions 442 and 444 driven by levers 446 and 448
and slidably receive stanchion racks 430 and 432. The stanchion
racks 430 and 432 include rack gears 434 and 436 that operably
couple with pinions 442 and 444. The levers 446 and 448 are rotated
to drive the pinions 442 and 444 along rack gears 434 and 436 to
adjust the height of the stanchion racks 430 and 432 relative to
the table or patient, or to vertically offset blades 470 and 472
relative to one another.
[0167] A pinion housing 422 is slidably attached to the stanchion
rack 432 towards its upper end. A rack 420 is attached at one end
to stanchion rack 430 and is slidably received in the pinion
housing 422. A pinion 424 driven by a lever 426 is rotatably
retained in the pinion housing 422 and operably connected to the
rack 420. The lever 426 is rotated to drive the pinion 424 along
the rack 420 to spread apart the stanchion racks 430 and 432 and
effectively a patient's ribs.
[0168] Torsional members 460 and 462 are attached to the top of the
stanchion racks 430 and 432. Blade arms 474 and 476 extend
outwardly from torsional members and attach to the blades 470 and
472. The torsional members comprise inner hubs 461 and 465
rotatably received in and operably connected to outer hubs 463 and
467. Locking levers 464 and 466 lock the inner hubs 461 and 465 in
place relative to the outer hubs 463 and 467.
[0169] In operation, the access platform 410 is positioned such
that the blades 470 and 472 can be inserted into an incision in a
patient's chest and then attached to the blade arms 474 and 476.
Once the blades 470 and 472 are positioned in the incision and
attached to the blade arms 474 and 476, the lever 426 is rotated to
spread the blades 470 and 472 and the patient's ribs apart. The
blades 470 and 472 can be effectively offset by rotating the inner
hubs 461 and 465 relative to the outer hubs 463 and 467. While the
blades 470 and 472 are rotated, the stanchion racks 430 and 432 can
be raised or lowered by rotating levers 486 and 488 to drive
pinions 442 and 444. By raising or lowering the stanchion racks 430
and 432, the blades 470 and 472 can be effectively raised or
lowered relative to one another to further offset the blades 470
and 472 relative to one another. A wrench 468 is utilized to rotate
the inner hubs 461 and 465 relative to the outer hubs 463 and
467.
[0170] Referring to FIG. 27, a tenth embodiment of the access
platform 510 of the present invention is shown. The access platform
510 comprises a rack 520 attached at one end to a spreader base 522
and at the other end to a handle 552. A blade 532 is attached to a
branch 530 of a blade arm 528. A stem 526 of the blade arm 528
extends from the branch 530 and is releasably received in a socket
524 formed in the spreader base 522. The branch 530 extends
downwardly from the stem 526 at an angle .THETA. offset from the
vertical V.sub.1.
[0171] A pinion housing 540 is slidably received over the rack 520
and rotatably retains a pinion 536 driven by a lever 538. The
pinion 536 is operably connected to the rack 520.
[0172] A blade 550 is attached to a branch 546 of a blade arm 548.
A stem 542 of the blade arm 548 extends from the branch 546 and is
releasably received in a socket 544 formed in the pinion housing
540. The branch 546 extends downwardly from the stem 542 at an
angle .PHI. offset from the vertical V.sub.2.
[0173] In operation, the blades 532 and 550 are inserted into an
incision in the patient's chest and then the stems 526 and 542 of
the blade arms 528 and 548 are inserted into the sockets 524 and
544. The lever 538 is rotated to drive the pinion 536 along the
rack 520 until the blades 532 and 550 and the patient's ribs are
positioned at a desired spacing. A spring loaded pawl 534 pivotally
mounted to the housing 540 locks the housing 540 in place along the
rack 520. The rack 520 is then lifted by the handle 552 to
vertically displace or offset the blade 550 and the patient's ribs
relative to the blade 532.
[0174] Turning to FIG. 28, an eleventh embodiment of the access
platform 651 comprises a spreader housing 602 that includes a drive
mechanism therein (not shown) and a drive slot 608 formed therein.
A spreader lever 604 is mounted on top of the spreader housing 602
and is operably connected to the drive mechanism housed therein. An
inferior blade 650 is interconnected to the drive mechanism via a
blade arm 640 which extends outwardly to the inferior blade 650
from the spreader housing 602 in a direction generally normal to
the housing 602. A tissue retractor 670 is attached to the blade
650 to assist in tissue retraction.
[0175] A pad arm 683 is formed integrally with the spreader housing
602 and extends longitudinally to a sternal pad 681. The pad arm
683 is generally arcuately shaped to conform to an extended rib
cage due to the offset of the patient's ribs.
[0176] A superior blade 652 having a tissue retractor 672 extending
therefrom is connected to the bottom end of a blade arm 642. The
top end of the blade arm 642 is pivotally connected to an offset
drive assembly 660. The offset drive assembly 660 comprises a guide
link 666 and a drive link 665 which are pivotally connected at
pivots 687 and 688 to a mount 685 extending upwardly from the pad
arm 683 and at pivots 668 and 667 to the blade arm 642. The drive
link 665 is also pivotally connected to a drive carrier 662 which
threadably captures a lead screw 661 and is traversely driven along
the lead screw 661 as the lead screw 661 is rotated. A lever 664 is
attached to the top of the lead screw 661 to rotate the lead screw
661. The base of the lead screw 661 is rotatably captured in a
bushing 663 which is rotatably captured in a drive mount 606
extending up from the spreader housing 602.
[0177] In operation, the inferior and superior blades 650 and 652
are inserted in an incision in the patient's chest capturing the
inferior and superior ribs adjacent to the incision. The pad arm
683 is sufficiently long to position the sternal pad 681 adjacent
the patient's upper sternal-costal area. After the blades 650 and
652 and sternal pad 681 are properly positioned, the spreader lever
604 is rotated to transversely drive the blade arm 640 connected to
the inferior blade 650 along the drive slot 608 to separate the
inferior and superior blades 650 and 652. Once the inferior and
superior blades 650 and 652 are separated to a desired spacing, the
offset assembly 660 is activated to lift the superior blade 652. As
the offset lever 664 is rotated in an appropriate direction, the
drive carrier 662 will be driven along the lead screw 661. As the
drive carrier 662 rises along the lead screw 661, the drive link
665 and guide link 666 pivot in a clockwise rotation about pivots
687 and 688 causing the superior blade 652 to rotate about a remote
center of rotation shown at 669. As the superior blade 652 is
rotated about the remote center of rotation 669, the pad arm 683
and sternal pad 681 apply the necessary torque against the
patient's upper sternal-costal area to maintain the lift on the
superior ribs.
[0178] In the offset position, with the superior blade 652
maintaining a lift of the superior ribs and the tissue retractors
670 and 672 engaged, a surgeon can dissect the IMA. With the
dissection of the IMA complete, the surgeon substantially levels
the inferior and superior blades 650 and 652 by reverse rotating
the lead screw 661. In the substantially level separated position,
the surgeon can perform an arteriotomy and an anastomosis. After
completion of these procedures, the surgeon disengages the soft
tissue retractor 670 and 672 and brings the blades 650 and 652
together by reverse rotation of the lever 604. The blades 650 and
652 can then be removed from the interior of the patient's chest.
With the blades 650 and 652 removed, the surgeon is able to close
the thoracotomy to complete the surgical procedure.
[0179] Referring to FIG. 29, a twelfth embodiment of an access
platform 659 is shown to comprise a modification of the eleventh
embodiment of the access platform 651 shown in FIG. 28. The offset
assembly 690 of the access platform includes an offset housing 691
extending upwardly from the spreader housing 602 and adapted to
slidably receive a curved rack 692. The blade arm 642 is attached
to the curved rack 692 through a slot 699 in the housing 691. A
worm gear 693 is positioned within the housing 691 and is operably
connected to the curved rack 692. A worm gear shaft 689 extends
from the worm gear 693 and connects to a lever 694 outside of the
housing 691. Thus, to lift the superior blade 652 and ribs, the
lever 694 is rotated in an appropriate direction to rotate the worm
gear 693 to drive the curved rack 692 upwardly and outwardly from
the housing 691. To lower the superior blade 652 from the offset
position, the lever 694 is reverse rotated to drive the curved rack
692 in an opposite direction.
[0180] Turning to FIG. 30, a thirteenth embodiment of the access
platform 655 of the present invention comprises a generally
elongated drive base 601 having a blade arm 640 and a pad arm 683
extending therefrom. The blade arm 640 extends in a generally
normal direction from the drive base 601, while the pad arm 683,
which is generally arcuately shaped, extends longitudinally and
downwardly from the drive base 601. The pad arm 683 terminates in a
sternal pad 681. A threaded shaft carrier 607 extends upwardly from
the drive base 601 adjacent the blade arm 640. An inferior blade
650 having a tissue retractor 670 extending therefrom attaches to
the blade arm 640. In a preferred construction, the inferior blade
650, tissue retractor 670, blade arm 640, threaded shaft carrier
607, drive base 601, pad arm 683, and sternal pad 681 are formed
from one-piece construction.
[0181] A hollow threaded shaft 603 is threaded through the shaft
carrier 607 and extends along the drive base 601 to rotatably
attach to a hollow drive block 609. A spreader handle 605 is
attached to the shaft 603 at an end opposite the drive block 609. A
worm gear 697 positioned in the drive block 609, is fixed to the
end of a shaft 696 that passes through the hollow threaded shaft
603 and attaches to an offset handle 695 beyond the spreader handle
605. The worm gear 697 is operably connected to an arcuate worm
gear rack 698 that is positioned within the drive block 609 and
connected to a branch 643 of a blade arm 642. The branch 643 of the
blade arm 642 extends from the blade arm 642 in a normal direction
and is pivotally mounted to the hollow drive block 609. The blade
arm 642 extends downwardly from the branch 643 and attaches to a
superior blade 652 with a tissue retractor 672 extending therefrom.
A follower 619 extends downwardly from the base of the hollow drive
block 609 and is received in a elongated drive slot 611 in the
drive base 601. As the drive block 609 is transversely driven along
the base 601 by the threaded shaft 603, the follower 609 slidably
follows the drive slot 611 in the drive base 601.
[0182] In operation, the blades 650 and 652 are inserted into an
incision in the patient's chest while the sternal pad 681 is
positioned adjacent the patient's upper sternal-costal area. After
the blades 650 and 652 and sternal pad are properly positioned, the
spreader handle 605 is rotated in an appropriate direction to
longitudinally and rotatably drive the threaded shaft 603 through
the shaft carrier 607 and thereby traversely drive the drive block
609 along the drive base 601 until the separation between the
blades 650 and 652 reaches a desired spacing. To offset the blades
650 and 652, the offset handle 695 is rotated in an appropriate
direction to rotate the worm gear 697 and drive the worm gear rack
698 in a clockwise direction. The rotation of the worm gear rack
698 in a clockwise direction pivots the superior blade 652 about
the branch 643 of the blade arm 642 in a clockwise rotation. By
rotating the superior blade 652 in a clockwise rotation, the
superior ribs captured by the superior blade 652 are lifted and a
torque necessary to maintain the lift of the ribs is applied to the
patient's upper sternal-costal area through the sternal pad
681.
[0183] By rotating the spreader and offset handles 605 and 695
simultaneously in an appropriate direction, the lifting of the
superior ribs is advantageously achieved while simultaneously
spreading the blades 650 and 652 or maintaining the already
retracted spacing between the blades 650 and 652 and corresponding
ribs. More particularly in regard to maintaining the retracted
spacing, by rotating the spreader handle 605 simultaneously with
the offset handle 695, the drive block 609 is traversely driven
along the drive base 601 to compensate for the rearward lateral
component of the superior blade's 652 motion as it travels upward
in a clockwise arc.
[0184] With the superior blade 652 and ribs raised in an offset
position, the surgeon can dissect the IMA. After completion of the
dissection of the IMA, the surgeon can substantially level the
blades 650 and 652 by reverse rotating both the offset handle 695
and the spreader handle 605 together. With the blades 650 and 652
in a level and separated position, the surgeon can perform an
arteriotomy and an anastomosis. After the completion of these
surgical procedures, the surgeon disengages the soft tissue
retractors 670 and 672 and brings the blades 650 and 652 together
by reverse rotating the spreader handle 605. The blades 650 and 652
are then removed from the interior of the patient's chest and the
thoracotomy is closed to complete the surgical procedure.
[0185] Referring to FIGS. 31 and 32, a fourteenth embodiment of the
access platform 610 of the present invention comprises a spreader
component 612 that includes a rack 613, a spreader base 614
attached to one end of the rack 613 and a pinion housing 620
slidably received over the rack 613. A pinion 621 that is driven by
a lever 622 is rotatably retained in the pinion housing 620 and
operably connected to the rack 613.
[0186] A fixed pivot 616 having a socket 618 formed therein,
extends from the spreader base 614. A fixed pivot lock 615 with a
lock screw 617 is fixedly connected to the fixed pivot 616. A
moveable pivot 624 having a socket 625 formed therein, extends from
the housing,620. Rotatably and releasably received in and extending
from the sockets 618 and 625 are stem portions 644 and 646 of a
pair of blade arms 640 and 642, respectively. The stem 644 that is
received in the socket 618 of the fixed pivot 616 includes a stop
645 formed on its exterior to abut the fixed pivot lock 615 and
stop the travel of the stem 644. Branch portions 641 and 643 of the
blade arms 640 and 642 extend downwardly from the stem portions 644
and 646 and attach to inferior and superior blades 650 and 652,
respectively. The superior blade 652 which is advantageously
located below and interconnected to the moveable pivot 624,
comprises a recessed throat 654 to capture a rib adjacent to an
incision in the patient's chest cavity and a pair of elongated
vanes 656 and 657 used to offset a plurality of the patient's ribs.
The inferior blade 650 which is interconnected to the fixed pivot
616 comprises a recessed throat 653 used to capture a rib adjacent
to an incision in the patient's chest cavity.
[0187] Tissue retractors 670 and 672 are attached to the blades.
The retractors 670 and 672 include a plurality of retractor fingers
673, 675 and 677, and 674, 676 and 678, respectively, extending
upwardly from the throat sections 653 and 654 of the blades 650 and
652. The retractors 670 and 672 are preferably constructed from
annealed sheet metal approximately 0.035 inch thick and are
preferably welded onto the blades 650 and 652.
[0188] The branch portion 643 of the blade arm 642 that is
interconnected to the moveable pivot 624 extends higher vertically
than the branch portion 641 of the blade arm 640 that is
interconnected to the fixed pivot 616 when the blades 650 and 652
are substantially level (see FIG. 29). This construction tends to
increase the moment about the moveable pivot 624 caused by the
offset of the movable pivot from the center-of-effort of the
spreading force at the blades 650 and 652. Because the movable
pivot 624 is located above the superior blade 652, a lifting force
is naturally exerted on the superior blade 652 and ribs as
spreading occurs.
[0189] To add additional offset of the superior blade 652 once the
blades 650 and 652 are separated and offset, a vertical
displacement component 630 is included on the access platform 610.
The vertical displacement component 630 comprises a rib compression
shoe 680, a substantially "S" shaped shoe arm 682 connected to the
shoe 680 at one end and pivotally connected to the stem 646 of the
blade arm 642 at the other end, and an adjustable offset link 632
connected to the pinion housing 620 and operably connected to the
shoe arm 682 and shoe 680. The shoe 680 has an arcuate front
profile and a rectangular top profile. A moveable pivot lock 626
with a lock screw 627 is fixedly mounted to the end of the shoe arm
682. The movable pivot lock 626 fixes the shoe arm 682 relative to
the blade arm 642.
[0190] The offset link 632 comprises a substantially "L" shaped
base 631 that extends from the pinion housing 620 at one end and
terminates at the other end in a pair of parallel spaced and
arcuate shaped fingers 633 and 634. A bushing 635 having a hole
tapped through its center perpendicular to the bushing's 635
longitudinal axis, is rotatably captured by the fingers 633 and
634. An adjustable offset drive screw 636 is threaded through the
hole in the bushing 635 and is operably connected to the shoe arm
682.
[0191] The adjustable offset drive screw 636 comprises a handle 637
attached to the top end of a jack screw 638. The base of the jack
screw 638 is formed as a hemisphere 639. The hemisphere 639
operably couples with a hemispherical recess 686 cut into a boss
684 that extends outwardly from the shoe arm 682. The boss 684 is
tilted upwardly at an angle .THETA. relative to the longitudinal
axis of the shoe arm 682. This construction ensures that the
hemisphere 639 will maintain contact with the boss 684 during
operation as the jack screw 638 forces the shoe arm 682 and shoe
680 to rotate downwardly in a clockwise direction.
[0192] In addition, the access platform 610 includes mounts (not
shown) attached to the blade arms 640 and 642. The mounts enable
the access platform 610 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 mounts advantageously eliminate the need for an
undesirable extra set of hands around the surgical site.
[0193] In operation, the blades 650 and 652 are inserted in an
incision in the patient's chest such that the elongated vanes 656
and 657 of the blade 652 are positioned under the patient's ribs
while the recessed throats 653 and 654 of the blades 650 and 652
are positioned to receive the ribs that are adjacent to the
incision. After the blades 650 and 652 are properly positioned, the
stem 644 of the blade arm 640 is inserted through the fixed pivot
lock 615 into the socket 618 of the fixed pivot 616. Meanwhile, the
stem 646 of the blade arm 642 is inserted through the moveable
pivot lock 626 and the end of the shoe arm 682 opposite the shoe
680, and into the socket 625 of the moveable pivot 624. The blade
650 is then fixed in position by tightening the fixed pivot lock
screw 617 to tighten the fixed pivot lock 615 around the stem 644
of the blade arm 640.
[0194] The rib compression shoe 680 is then adjusted downwardly by
adjusting the adjustable offset drive screw 636 until the desired
compression of the ribs is achieved. The blade 652 that is
interconnected to the moveable pivot 624 is then fixed in position
relative to the shoe 680 by tightening the moveable pivot lock
screw 627 to tighten the moveable pivot lock 626 around the stem
646 of the blade arm 642. The ribs are then separated and
simultaneously offset by rotating the lever 622 to drive the pinion
621 along the rack 613 until a desired opening width is realized.
Because the movable pivot 624 is advantageously located above the
blade 652, the superior blade 652 naturally raises vertically as it
rotates about the moveable pivot 624 as a spreading force from the
inferior blade 650 is transmitted to the superior blade 652 through
the movable pivot 624.
[0195] Further adjustment of an offset height of the superior
blades 652 may be obtained by first loosening the moveable pivot
lock 626 abound the stem 646 of the blade arm 642 and then
adjusting the adjustable offset drive screw 636 to cause the shoe
680 and the shoe arm 682 to rotate downwardly in a clockwise
direction relative to the superior blade 652 and, thus, cause the
blade 652 that is interconnected to the moveable pivot 624 to rise
vertically until a desired offset is achieved. Alternatively, the
blade arm 642 would remain fixed to the shoe arm 682 as the offset
drive screw 636 is adjusted to cause the shoe 680 and shoe arm 682
to rotate downwardly in a clockwise direction. The clockwise
rotation of the shoe 680 and shoe arm 682 causes the blade 652 to
rotate upwardly in a clockwise direction.
[0196] After the ribs have been retracted and vertically displaced,
the tissue retractors 670 and 672 are operated to retract the soft
tissue away from the incision area by bending fingers 673, 675, and
677, and 674, 676, 678 over the patient's chest. By bending the
retractor fingers 673, 674, 675, 676, 677 and 678 over the
patient's chest, the fingers 673, 674, 675, 676, 677 and 678
advantageously press down against the soft tissue to retract it
away from the incision and out of the surgeon's working area.
[0197] In the offset position, with the superior blade 652 raising
the patient's ribs, the surgeon can dissect the IMA. With the
dissection of the IMA complete, the surgeon substantially levels
the blades 650 and 652 by reverse rotating the adjustable offset
drive screw 636 and then either removes the access platform 610
completely or engages a heart stabilizer 67 as shown in FIG. 1.
With the heart stabilizer 67 engaged to minimize the movement of
the heart, the surgeon performs an arteriotomy and anastomosis.
After completion of the arteriotomy and anastomosis, the surgeon
removes the stabilizer 67, disengages the soft tissue retractors
670 and 672 and brings the blades 650 and 652 together. The blades
650 and 652 are then disengaged from the access platform 610 and
then removed from the interior of the patient's chest. With the
blades 650 and 652 removed, the surgeon is able to close the
thoracotomy to complete the surgical procedure.
[0198] A fifteenth embodiment of an access platform 700 of the
present invention, as shown in FIGS. 33 and 34, comprises an
elongated spreader housing 702 with a block and tackle type drive
mechanism 970 located therein (see FIGS. 35-38 discussed in detail
below). A lever 701 interconnected to the drive mechanism 970
extends upwardly from the spreader housing 702. A blade arm 705
connected to an inferior blade 706 is mounted to a base 704 fixedly
received in the housing 702. The blade arm 705 extends outwardly
and then downwardly from the spreader housing 702 to the inferior
blade 706. The inferior blade 706 includes a tissue retractor 707
extending therefrom.
[0199] A drive block 708 coupled to the drive mechanism 970 in the
spreader housing 702, extends outwardly from the spreader housing
702 in a normal direction to the housing 702. As the lever 701 is
rotated, the drive mechanism 970 slidably carries the drive block
708 along the drive slot 703 of the spreader housing 702.
[0200] A blade arm 711 is attached at its lower end to a superior
blade 712 with a tissue retractor 713 extending therefrom. At its
upper end, the blade arm 711 is rotatably coupled to an upper end
of an elongated arcuate pad arm 715. The pad arm 715 is attached at
its lower end to a sternal pad 714. The upper end of the pad arm
715 forms a forked hub 716. The blade arm 711, pad arm 715 and
sternal pad 714 assembly is releasably and rotatably mounted on a
cylindrical shaft 710 attached to the drive block 708.
[0201] The access platform 700 incorporates an offset positioning
assembly 717 that comprises a pawl 719 pivotally mounted in a
recess 723 of the pad arm 715 at a pivot 722 and a ratchet 718
formed on the upper end of the blade arm 711. The pawl 719 includes
a pawl nose 721 that engages the ratchet 718 and a pawl lever 720
that is depressed to pivot the pawl 719 about pivot 722 to
disengage the pawl nose 721 from the ratchet 718. With the pawl
nose 721 engaged, the pad arm 715 can only rotate in a clockwise
direction relative to the blade arm 711. The pawl 719 prevents the
hub 716 of the arm 715 from rotating in a counterclockwise
direction relative to the blade arm 711. With the pawl nose 721
disengaged from the ratchet 718, the pad arm 715 can freely rotate
relative to the blade arm 711 in a counterclockwise direction.
[0202] A In operation, with the superior blade 712 and sternal pad
714 assembly separated from the rest of the access platform 700,
the superior blade 712 and sternal pad 714 assembly is positioned
on the patient's chest. Initially the angle between the blade and
pad arms 711 and 715 is large or nearly flat. The superior blade
712 is then inserted into an incision in the patient's chest wall
and slid under the superior ribs adjacent to the incision. With the
superior blade 712 properly positioned within the incision, the
sternal pad 714 is adjusted downwardly on top of the patient's
chest wall by rotating the pad arm 715 relative to the blade arm
711 in a clockwise direction to decrease the angle between the pad
arm 715 and blade arm 711.
[0203] Next, the rest of the access platform 700 with the inferior
blade 706 attached, is aligned on the patient's chest. The inferior
blade 706 is then inserted into the incision in the patient's
chest. The blade arm 711 and pad arm 715 assembly is then rotatably
mounted on the shaft 710. The access platform 700 is now fully
assembled and the blades 706 and 712 are in parallel alignment.
[0204] The handle 701 is rotated to spread the blades 706 and 712.
Because the shaft 710 is located above the superior blade 712 and
because the superior blade 712 and sternal pad 714 assembly pivots
freely around the shaft 710 a lifting of the superior blade 712 and
ribs naturally occurs as the blades 706 and 712 are separated. The
spreading force from the inferior blade 706 is transmitted to the
superior blade 712 through the shaft 710 located above the superior
blade 712. With the blades 706 and 712 offset, the surgeon can
harvest the IMA. Upon completion of the IMA harvest, the handle 701
is rotated in a reverse direction to bring the blades fully
together. With the blades 706 and 712 together, there is
substantially no spreading force being exerted on the superior
blade 712 and sternal pad 715 assembly. The pawl lever 720 can then
be depressed to disengage the pawl nose 721 from the ratchet 718.
With the pawl 719 disengaged, the sternal pad 714 and pad arm 715
are raised allowing removal of the access platform 700 from the
incision.
[0205] Referring to FIG. 39, a sixteenth embodiment of an access
platform 780 comprises a generally elongated drive base 781 having
a blade arm 782 extended generally in a normal direction from the
drive base 781. A generally arcuate pad arm 786 extends generally
longitudinally and downwardly from the drive base 781 and
terminates at a sternal pad 785. A bearing support 791 extends
upwardly from the drive base 781 adjacent the blade arm 782. An
inferior blade 783 having a tissue retractor 784 extending
therefrom attaches to the end of the inferior blade arm 782. In a
preferred construction, the inferior blade 781, tissue retractor
784, blade arm 782, bearing support 791, drive base 781, pad arm
786 and sternal pad 785 are formed from one-piece construction.
[0206] A bearing 792 is mounted to the bearing support 791 and has
a spreader handle 793 operably coupled thereto. A drive screw 787
having an offset handle 794 with a lever 795 attached to its first
end, is threaded through the spreader handle 793 and freely passes
through the bearing 792 and bearing support 791. The drive screw
787 extends longitudinally along the drive base 781 and is threaded
through a carrier mount 789. The spreader handle 793 and the
carrier mount 789 include oppositely wound threads. Rotation of the
spreader handle 793 traversely drives the drive screw 787 and the
carrier mount 789 mounted thereon along the drive base 781 and,
thus, spreads or closes the blades 783 and 796. The carrier mount
789 includes a follower extending downwardly from its base that
inserts into a drive slot 788 in the base 781. As the carrier mount
789 is translated across the drive base 781, the follower slides
along the drive slot 788.
[0207] Extending upwardly and longitudinally outwardly in a
direction away from the spreader handle 793, a carrier arm 790
extends from the carrier 789. At an end opposite the carrier mount
789, the carrier arm 790 pivotally captures at a pivot 799 a branch
797A of a blade arm 797. A tab 779 is fixed to the branch 797A
adjacent the pivot 799 and extends downwardly in a direction normal
to the branch 797A. The tab 779 contacts a shaft-end 787A of the
drive shaft 787 opposite the offset handle 794 and extending beyond
the carrier 789. The branch 797A extends outwardly from the pivot
799 in a normal direction to the carrier arm 790 and couples to the
blade arm 797 at an end opposite the carrier arm 790. The blade arm
797 is generally arcuately shaped and extends downwardly from the
branch 797A to connect to a superior blade 796 with a tissue
retractor 798 extending therefrom. Because the pivot 799 is located
above the superior blade 796, a lifting force is exerted on the
superior blade 796 and ribs as a spreading force from the inferior
blade 783 is transmitted to the superior blade 796 through the
pivot 799.
[0208] Rotation of the offset handle 794, while holding the
spreader handle 793 stationary, will thread the drive screw 787
through both the spreader handle 793 and the carrier 789, and
thereby cause the drive screw 787 and carrier 789 to traverse the
drive base 781 as well as causing the carrier 789 to traverse the
drive screw 787 in the same direction. As a result, the carrier 789
traverses the drive base 781 at approximately two-times the speed
that the carrier 789 traverses the drive screw 787 and thus, the
length of the shaft-end,787A extending beyond the carrier 789 will
increase or decrease at approximately one-half the speed at which
the carrier 789 traverses the drive base 781. Therefore, as the
offset handle 794 is rotated in a direction to spread the ribs, the
ribs will be raised at a rate slower than they are spread as the
superior blade 796 naturally rotates about the pivot 799 as the
length of the shaft-end 787A extending beyond the carrier 789
decreases. Similarly, as the offset handle 794 is rotated in a
direction to lower the offset ribs, the length of the shaft-end
787A will increase, at a rate slower than the rate at which the
carrier 789 traverses the drive base 781. As the length of the
shaft end 787A increases, it forces the tab 779, and thus the
superior blade 797, to rotate in the counterclockwise direction
around the pivot 799, and thereby further lowers the ribs. Because
the carrier 789 traverses the drive base 781 at a faster rate than
the shaft-end 787A increases, the distance between the blades 783
and 796 along the drive base 781 tends to decrease as the ribs are
lowered.
[0209] To increase the rate at which the blades 783 and 796 are
spread or closed relative to the rate at which the superior blade
796 is raised or lowered, the spreader and offset handles 793 and
794 are simultaneously counter-rotated relative to one another.
Such a manipulation of the handles 793 and 794 will increase the
rate at which the drive screw 787 traverses the drive base 781 and,
thus, increase the rate at which the carrier 789 traverses the
drive base 789 relative to the rate at which the carrier 789
traverses the drive screw 787 and increases or decreases the shaft
end 787A.
[0210] To decrease the rate at which the blades 783 and 796 are
spread or closed relative to the rate at which the superior blade
796 is raised or lowered, the spreader and offset handles 793 and
794 are rotated simultaneously in the same direction. By rotating
the handles 793 and 794 in the same direction, the drive screw 787
is not translated in either direction along the drive-base 781.
Thus, the carrier 789 will traverse the drive base 781 at the same
rate it traverses the drive screw 787 and, therefore, the length of
the shaft-end 787A will increase or decrease at the same rate at
which the carrier 789 traverses the drive base 781. As a result,
when the handles 793 and 794 are rotated in a direction to lower
the superior blade 796, the spacing between the blades 783 and 796
along the drive base 781 remains relatively constant as the carrier
789 and the superior blade 796 traverse in opposite directions
relative to the drive base 781.
[0211] In operation, the inferior and superior blades 783 and 796
are inserted into an incision in the patient's chest while the
sternal pad 785 is positioned adjacent the patient's upper
sternal-costal area. After the blades 783 and 796 and the sternal
pad 785 are properly positioned, if the surgeon only desires to
spread the ribs, only the spreader handle 793 is rotated in an
appropriate direction to traversely drive the drive screw 787 and
the carrier 789 along the drive base 781. As the carrier 789 is
driven along the drive base 781, the superior blade 796 is
separated from the inferior blade 783. If the surgeon wishes to
raise the ribs as well as spread the ribs, the offset handle 794 is
rotated in an appropriate direction to traversely drive the drive
screw 787 and carrier across drive base 781 as well as traversely
drive the carrier 789 along the drive screw 787. The spreader
handle 793 is either held stationary, counter-rotated or rotated in
the same direction, depending upon the desired rate of rib lift
relative to the rate of rib spreading. As the blades 783 and 796
separate and the shaft-end 787A decreases, the superior blade 796
and ribs naturally lift and rotate in a clockwise direction about
the pivot 799 as a torque is applied through the sternal pad 785 to
the upper sternal-costal area of the patient's chest to maintain
the lift in the superior blade 796 and ribs. While in the offset
position, the surgeon can dissect the IMA.
[0212] To lower the superior blade 796 and ribs while maintaining
the lateral separation of the blades 783 and 796, the offset and
spreader handles 793 and 794 are simultaneously rotated in the same
direction. As noted above, the drive screw 787 does not traverse
the drive base 781 as the drive screw 787 is threaded through the
carrier 789 to traversely drive the carrier 789 along the drive
screw 787 and the drive base 781, as well as to increase the length
of the shaft 787A beyond the carrier 789. As the length of the
shaft-end 787A increases it tends to force the tab 779 to rotate in
a counterclockwise direction about the pivot 799. Rotation of the
tab 779 in a counterclockwise direction will rotate the superior
blade 796 and ribs in a counterclockwise direction, and thereby
lower the superior blade 796 and ribs. The counterclockwise motion
of the superior blade 796 includes a lateral component that is
directed away from the carrier 789 and which enables the lateral
separation of the blades 783 and 796 to be substantially maintained
as the superior blade 796 is lowered. With the blades 783 and 796
substantially level, the surgeon can perform other surgical
procedures such as an arteriotomy and anastomosis.
[0213] Turning to FIG. 40, a seventeenth embodiment of the access
platform 800 comprises a spreader housing 801 which includes a
drive mechanism housed therein (not shown) and a drive slot 803 cut
into the spreader housing 801. A spreader lever 802 is mounted on
the top of the spreader housing 801 and is operably connected to
the drive mechanism housed therein. An inferior blade 805 having a
tissue retractor 804 extending therefrom, is interconnected to the
drive mechanism via a blade arm 806. The blade arm 806 extends
outwardly from the spreader housing 801 in a generally normal
direction.
[0214] A pad arm 817 connects at one end, or is formed integrally
therewith, to the spreader housing 801 and extends outwardly
therefrom. A sternal pad 816 is integrally formed on the pad arm
817 at an end opposite the housing 801. The pad arm 817 is
generally arcuate to conform to an extended rib cage due to the
offset of the ribs.
[0215] A superior blade 820 having a tissue retractor 821 extending
therefrom, is connected to the bottom end of a generally arcuately
shaped blade arm 818. The top end of the blade arm 818 is pivotally
mounted on an offset stanchion 815 that extends upwardly from the
pad arm 817. A compression member 813 is pivotally connected to the
top of the stanchion 815 at pivot 814 and extends inwardly from the
stanchion 815 toward the lever 802 on the spreader housing 801. An
offset screw 811 having a handle 812 attached to its top end, is
threaded through the compression member 813 at an end opposite the
pivot 814 and is rotatably captured by a bushing assembly 808
rotatably coupled to a mount 807 that extends upwardly from the
spreader housing 801. A counter-lift tab 809 extends inwardly from
the blade arm 818 adjacent the stanchion 815. The lift tab 809 is
operably connected to the compression member 813 through an offset
spring 810 mounted therebetween.
[0216] In operation, the superior blade 820 and ribs are naturally
lifted as the blades 805 and 820 are separated. Because the pivot
819 is located above the superior blade 820, a lifting force is
exerted on the superior blade 820 and ribs while spreading is
occurring. The spreading force from the inferior blade 805 is
transmitted to the superior blade 820 through the high-mounted
pivot 819. However, the lift of the ribs or, more particularly, the
rotation of the superior blade 820 about the pivot 819 in a
clockwise direction is inhibited by the force exerted by the offset
spring 810. The superior blade 820 and ribs will not begin to lift
until the moment force caused by the rotation of the superior blade
820 about the pivot 819 is greater than the spring force exerted by
the offset spring 810 on the lift tab 809. The spring force is
adjustable, and hence the amount of offset is adjustable, by
rotating the handle 812 to lower or raise the compression member
813 along the offset screw 811. As the compression member 813 is
lowered or brought closer to the tab 809, the spring force exerted
by the offset spring 810 is increased, and hence the amount the
superior blade 820 is lifted or rotated is decreased. Thus, the
adjustable spring force can be used in a "pre-set" mode by the
surgeon.
[0217] Referring to FIGS. 41-48, eighteenth and nineteenth
embodiments of an access platform 730, 729 of the present invention
advantageously lift and separate the superior blade 740 from the
inferior blade 741 in a single motion. The access platform 730,
shown in FIGS. 41-47, includes inferior and superior blades 741 and
740. The inferior blade 741 includes an elongated top portion for
compression while the superior blade 740 includes an elongated
bottom portion for lifting. The blades 740 and 741 are
interconnected via an offset spreader assembly 731. The offset
spreader assembly 731 includes an elongated handle 732 which is
pivotally mounted adjacent its midpoint to an inferior blade mount
735 at a pivot 739 and is pivotally mounted adjacent a first end to
a superior blade mount 734 at a pivot 736. The inferior blade mount
735 extends upwardly from the top of the inferior blade 741 and the
superior blade mount 734 extends downwardly from the back side of
the superior blade 740. A stabilizing link 733 is pivotally mounted
to the superior blade mount 734 at pivot 737 and the inferior blade
mount 735 at pivot 738. As the link 733 extends between the blades
740 and 741, it remains substantially parallel to the handle
732.
[0218] Turning to FIG. 42, the access platform 730 is shown in a
closed position with the superior and inferior blades 740 and 741
engaging the superior and inferior ribs, respectively. Force is
applied to a free second end of the handle 732 to rotate the handle
732 in a counterclockwise rotation about pivot 739 (see FIG. 43).
As a result, the first end of the handle 732 that is pivotally
attached to the superior blade mount 734 at pivot 736, lifts and
separates the superior blade 740 and ribs in a single motion-from
the inferior blade 741 and ribs.
[0219] Turning to FIGS. 44-47, the offset spreader assembly 731 of
the access platform 730 is removable. An offset positioning
assembly 748 is utilized to maintain the lift and separation
between the blades 740 and 741 and advantageously open up the
surgeon's access to dissect the IMA. The removable offset spreader
assembly 731 incorporates a dovetail type assembly to mate the
blade mounts 734 and 735 with the blades 740 and 741, respectively.
Pins 742 and 743 which protrude from the back side of the superior
blade 740 and the top side of the inferior blade 741 mate with
tails 744 and 745 formed in the blade mounts 734 and 735,
respectively.
[0220] The offset positioning assembly 748 comprises a positioning
arm 749 having shafts 750 and 751 extending therefrom at opposing
ends. The shafts 750 and 751 mate with holes 757 and 756 formed in
positioning mounts 746 and 747 extending up from the inferior and
superior blades 741 and 740. The shafts 750 and 751 and the holes
757 and 758 include finely cut splines to maintain the discreet
positions of the blades 740 and 741 relative to one another. An
arcuate pad arm 756 terminates into a forked hub 759 at one end and
a sternal pad 755 at another end. The hub 759 rotatably captures
the shaft 751 on a side of the positioning arm 749 opposite the
positioning mount 774. A pawl 753 pivotally captured in a recess in
the pad arm 756 engages a ratchet 754 mounted on the shaft 751. The
sternal pad 755, pad arm 756 and hub 759 are free to rotate about
the shaft 751 in a clockwise direction. To rotate the sternal pad
755, pad arm 756 and hub 759 in a counterclockwise direction, the
pawl 753 is depressed at an end opposite the ratchet 754 to
disengage the pawl 753 from the ratchet 754. With the pawl 753
disengaged, the hub 759 is free to rotate about the shaft 751 in a
counterclockwise direction.
[0221] In operation, the handle 732 is first rotated in a
counterclockwise direction to lift and separate the superior blade
740 and ribs from the inferior blade 741 and ribs. Once in the
offset position, the offset positioning assembly 748 is engaged by
sliding the shafts 750 and 751 into the holes 757 and 758 of the
positioning mounts 746 and 747 on the inferior and superior blades
741 and 740. The pad arm 756 is rotated downwardly until the
sternal pad 755 contacts the patient's chest (see FIG. 47). The
offset spreader assembly 731 is then removed by sliding the tails
744 and 745 of the blade mounts 734 and 735 off of the pins 742 and
743 of the blades 740 and 741. With the offset spreader assembly
731 removed, the offset positioning assembly 748 holds the blades
740 and 741 apart and applies the necessary torque against the
patient's upper sternal-costal area to maintain the lift on the
superior blade 740 and ribs. While in the offset position, the
access to dissect the IMA is wide open.
[0222] Referring to FIG. 48, an offset spreader assembly 760 of a
nineteenth embodiment of the access platform 729 includes a
U-shaped handle 761 pivotally connected to inferior blade mounts
771 and 770 at pivots 764 and 765, and superior blade mounts 768
and 769 at pivots 766 and 767. A pair of parallel stabilizing links
762 and 763 are pivotally connected to superior blade mounts 768
and 769 at pivots 773 and 774 and inferior blade mounts 770 and 771
at pivots 775 and 776. The inferior blade mounts 770 and 771 extend
upwardly from the inferior blade 741 while the superior blade
mounts 768 and 769 extend downwardly from the superior blade
740.
[0223] In operation, force is applied to the free end of the handle
761 to rotate the handle 761 in a counterclockwise direction about
pivots 764 and 765 on the inferior blade mounts 771 and 770 and
lift and separate the superior blade 740 in a single motion from
the inferior blade 741. The U-shaped handle 761 and stabilizing
links 762 and 763 facilitate the lateral stability of the access
platform 729. In the offset position, the handle 761 and links 762
and 763 advantageously remain clear of the access space, and thus
provide the surgeon with open access to dissect the IMA.
[0224] Turning to FIGS. 49-52, a bladeless twentieth embodiment of
the access platform 825 comprises a tubular retractor body 828
having concave shaped sidewalls 831 extending between a top edge
827 and a bottom edge 826 of the body 828. Extending vertically
from the top edge 827 of the tubular body 828 is a pair of
elongated handles 829 and 830. The handles 829 and 830 may be
formed integrally with the body 828 or removably or hingedly
coupled to the body 828.
[0225] In operation, the tubular body 828 with its advantageously
sloped bottom edge 826, is wedged between the inferior and superior
ribs. Once in position, the handles are used to rotate the tubular
body 828 approximately 90.degree. (see FIGS. 51 and 52) to offset
the superior and inferior ribs. While in the offset position, the
surgeon can dissect the IMA. While in the upright position, the
surgeon can perform such surgical procedures as an arteriotomy and
an anastomosis. Preferably, the access platform 825 is formed from
a resilient polymer or stainless steel, and can be easily
constructed as a single piece.
[0226] Referring to FIGS. 53-56, a bladeless twenty-first
embodiment of the access platform 840 is formed as a three-piece
hollow cone 841 having threads 842 wrapped about the full exterior
of the cone 841. The cone 841 includes a hollow frustum shaped
intermediate member 844 interconnected to a conically shaped tip
member 843 and a hollow frustum shaped top member 845. The top and
tip members 845 and 843 are connected to the intermediate member
844 at parting lines 838 and 839, respectively, and locked in place
with locking tabs 846. The locking tabs 846 are slidably received
in locking grooves 847 (see FIG. 56). The locking tabs 846 prevent
upward vertical movement of the tip member 843 relative to the
intermediate member 844 and upward vertical movement of the
intermediate member 844 relative to the top member 845. Relative
rotational movement between coupled members is prevented by splined
connections 849. Finger or driving tool pockets 848 are included in
the interior of the top, intermediate and tip members 845, 844 and
843 to aid in the manipulation of the cone 841.
[0227] In operation, the tip member 843 pierces the tissue and
draws the intermediate member 844 downward toward the ribs as the
cone 841 is rotated. As the intermediate member 844 is drawn
downward it begins to spread the inferior and superior ribs while
the threads 842 engage the inferior and superior ribs to maintain
the vertical position of the cone 841. With the intermediate member
844 properly in position, the tip member 843 is removed from the
cone 841. The cone 841 is rotated until the top member 845
separates the inferior and superior ribs and the threads 842 about
the top member 845 engage the inferior and superior ribs. With the
top member 845 properly in position, the intermediate member 844 is
removed from the cone 841 leaving only the top member 845 in place
between the inferior and superior ribs, and thus, providing access
to the patient's heart for the surgeon to perform surgical
procedures.
[0228] A variety of drive mechanisms discussed below (FIGS. 35-38
and 57-65) could be incorporated in the access platform embodiments
discussed herein. Referring to FIGS. 35-38, a drive mechanism 970
preferably comprises a modified block and tackle assembly. The
drive mechanism 970 includes a pulley 971 mounted in the spreader
housing 702 at a first end, two intermediate pulleys 972 and 973
mounted on the drive block 708 which is interconnected to a
superior blade and slidably positioned within the housing 702, and
a pulley 974 and a clutch 976 mounted in the housing at a second
end adjacent the base mount 704 which is interconnected to an
inferior blade and fixedly mounted within the housing 702. A cable
988 is conventionally wrapped around the pulleys 971, 972, 973 and
974 and clutch 976 to transversely drive the drive block 708 away
from the base mount 704 to spread the superior and inferior ribs.
The two ends of the cable 988 are tied to a tensioning spring 987
mounted in the drive block 708. The cable tensioning spring 987
provides a preload force (preferably about three pounds) necessary
to maintain a sufficient preload tension on the drive cable
988.
[0229] Referring to FIGS. 36-38, the clutch mechanism 976 includes
a clutch housing 977 having a cylindrical capstand 978 mounted
therein and a hub 979 coaxially positioned within the capstand 978.
A hub shaft 980 extends upwardly from the hub 979 out of the
spreader housing 702 where it is coupled to the lever 701 (see FIG.
33). Two opposing dowel pins 985 and 986 reside longitudinally
along the circumference of the hub 979. The dowel pins 985 and 986
are partially captured in longitudinal recesses 989 and 990 formed
in the interior of the capstand 978 and in a slot 981 bored through
the hub 979. A spring mechanism comprising three parallel springs
982, 983 and 984 resides in the slot 981 and biases the dowel pins
985 and 986 outward with a force F1.
[0230] The amount of drive or output force that can be exerted on
the superior blade is dictated by the diameter of the capstand 978
and the number of times the cable 988 is wound around the capstand
978. Thus, as the diameter of the capstand 978 is increased, the
amount of force that can be exerted by the drive mechanism 970 on
the blades is decreased. In addition, as the number of times the
cable is wound around the capstand 978 increases, the amount of
force that the drive mechanism 970 can exert on the blades is
increased.
[0231] Preferably, the drive mechanism 970 provides about 50 pounds
(.+-.10-15%) of drive force on the blades with a minimum force of
preferably about 10 to 20 pounds being applied to the lever 701.
Only about 30-40 pounds of drive force is necessary to spread the
ribs on the heaviest of patients. The clutch 976 advantageously
provides a slip or overdrive mechanism which ceases the drive force
on the blades. This slip force (F slip) is preferably about 50
pounds. At the prescribed slip force, enough torque is transmitted
by the capstand 978 on the dowel pins 985 and 986 to overcome the
spring bias F1 on the dowel pins 985 and 986 and push the dowel
pins 985 and 986 within the slot 981 of the hub 979 such that the
hub 979 slips within the capstand 978. As the hub 979 slips within
the capstand 978, the blades are prevented from being spread any
further and, thus, advantageously prevented from accidentally
breaking any of the ribs.
[0232] Referring to FIG. 57, a drive mechanism 850 comprises a lead
screw 853 that is mounted in an elongated carrier 852 and operably
coupled to a drive lever 851 at a gear box 860. The lead screw 853
includes oppositely wound threads on first and second portions 854
and 855 of the lead screw 853. The lead screw 853 is operably
coupled to a pair of drive blocks 856 and 857 that are slidably
mounted on the carrier 852 and coupled to blade arms 858 and 859,
respectively. The rotation of the lead screw 853 in a first
direction causes the drive blocks 856 and 857 to separate and in
turn separate a patient's ribs. The rotation of the lead screw 853
in a second direction draws the drive blocks 856 and 857
together.
[0233] Referring to FIGS. 58 and 59, the gear drive of the drive
mechanism 850 includes either an assembly of worm gears 862 and 863
or an assembly of bevel gears 864 and 865. The worm gear 862, 863
(FIG. 58) arrangement tends to provide a high ratio drive which
results in slow separation of the drive blocks-856 and 857. The
threads on the lead screw 853, however, include a long or steep
pitch to increase the speed of adjustment of the drive blocks 856
and 857. With a worm-gear drive mechanism 862, 863, back driving of
the drive blocks 856 and 857 is inherently prevented.
[0234] In the bevel gear 864, 865 (FIG. 59) drive arrangement, the
drive ratio is substantially 1:1 which results in a fast separation
of the drive blocks 856 and 857. To compensate for this fast
adjustment, the lead screw 853 includes shallow or short pitched
threads. A pawl (not shown) is operably coupled to the threads of
the lead screw 853 to prevent back driving of the drive blocks 856
and 857. If the pitch of the threads is sufficiently shallow or
short, back driving will be inherently prevented and, thus, the
need for a pawl will be eliminated.
[0235] Referring to FIG. 60, an access platform includes a
combination of the harmonic gear drive 20 and spreader assembly of
the first embodiment discussed herein (FIGS. 2 and 3) and pivotally
coupled blade arms of the fifth embodiment discussed herein (FIG.
19). In addition, the blades 350 and 352 are curved to compensate
for the orientation of the access platform relative to the ribs of
the patient.
[0236] Turning to FIG. 61, an access platform 869 resembling the
fourth embodiment shown in FIG. 18, includes a drive assembly 870
comprising spreader arms 874 and 875 coupled to a drive 872 having
a drive lever 871. Spreader links 876 and 889 are pivotally coupled
to spreader arms 874 and 875, respectively, and to blade arm mounts
881 and 882, respectively. Blade arms 883 and 884 are pivotally
coupled to the blade arm mounts 881 and 882, respectively, and are
connected to blades 885 and 886, respectively. The blades 885 and
886 include tissue retractors 887 and 889.
[0237] To advantageously maintain a parallel arrangement between
the blades as they are separated, inner and outer guide links 877
and 878, 879 and 880, respectively, are pivotally coupled to the
blade arm mounts 881 and 882 and a spreader base 873.
[0238] Referring to FIG. 62, a drive mechanism 890 comprises a pair
of curved gear racks 905 and 906 formed on the interior of blade
arms 892 and 893, which are pivotally connected at a main pivot
891. Dual pinion gears 898 and 899 are operably connected to one
another and to the curved racks 905 and 906, and are coupled
together by a support 901. A handle 909 drives the first pinion 898
which drives the second pinion 899. A pawl 903, pivotally connected
to the support 901, engages the teeth of the first pinion 898 to
prevent back drive of the dual pinion gears. A common pin 902 used
to pivotally mount the pawl 903 on the support 901 follows along a
track 904 in the blade arm 892 to maintain contact between the
second pinion 899 and the curved rack 906. A tensioning spring 907
attached to the blade arms 893 and 892 acts to maintain contact
between the curved rack 905 and the first pinion 898. The curved
gear racks 905 and 906 advantageously cause a constant effort to be
exerted on the handle 900 as the blade forces on the blades 894 and
895 increase due to the separation of the ribs. More particularly,
as the blade forces increase as the pinion gears 898, 899 move
closer to the pivot 891, a given rotation of the handle 900 will
open the blades a progressively small distance and, thus, keep the
forces at the handle 900 relatively constant.
[0239] Referring to FIG. 63, a drive mechanism 910 is coupled to
blade arms 914 and 915. The drive mechanism 910 comprises a lead
screw having first and second portions 912 and 913 having
oppositely wound threads. A drive handle 932 is attached to one end
of the lead screw 911. Drive blocks 917 and 916 are threadably
carried on the first portion 912 of the lead screw 911. A drive
block 918 is threadably carried on the second portion 913 of the
lead screw 911. First and second links 929 and 930 are pivotally
connected to the drive block 918 and the blade arms 914 and 915,
respectively. Third and fourth links 925 and 924 are pivotally
connected to the drive block 917 and the blade arms 914 and 915,
respectively, at common pivots 926 and 928. Fifth and sixth links
919 and 920 are pivotally connected to the drive block 916 and
blade arms 914 and 915, respectively.
[0240] In operation, the lead screw 911 is rotated in a first
direction to transversely drive the drive blocks 917 and 916 and
the drive block 918 in a direction away from each other, thereby
drawing the blade arms 915 and 914 together. As the lead screw 911
is rotated in a second direction, the drive blocks 916 and 917 and
the drive block 918 are transversely driven in a direction toward
each other, thereby separating the blade arms 914 and 915. The
links 919 and 920 operate to keep the blade arms 914 and 915
parallel.
[0241] Referring to FIG. 64, a drive mechanism 935 is coupled to
pivotally connected blade arms 941 and 942. The drive mechanism 935
comprises a gear box 936 having a first bevel gear 939 attached to
a lead screw 940 and operably coupled to a second bevel gear 938
attached to a handle 937. First and second links 943 and 944 are
pivotally connected to the blade arms 941 and 942, respectively,
and to a drive block 945 threadably carried on the lead screw 940.
The drive handle 937 may alternatively be mounted more simply on
the end of the lead screw 940.
[0242] In operation, the handle 937 is rotated to traversely drive
the drive block 945 along the lead screw 940 to draw in or push out
the blade arms 941 and 942.
[0243] Referring to FIG. 65, a double scissor drive linkage 950 is
coupled to parallelly disposed blade arms 969A and 969B. The drive
mechanism 950 comprises a lead screw 952 having a rotatably
captured carrier 953 on one end and a handle 951 attached to the
other end. First and second links 956 and 958 are pivotally
connected to the blade arms 969A and 969B, respectively, and to a
drive block 954 threadably carried on the lead screw 952. Third and
fourth links 955 and 957 are pivotally connected at their first
ends to the carrier 953 and slidably and pivotally connected at
their second ends to the blade arms 969A and 969B. Pivot followers
965 and 966, attached to the third and fourth links 955 and 957,
are slidably and pivotally captured in guide slots 967 and 968
formed in the blade arms 969A and 969B. In addition, the first and
second links 956 and 958 are pivotally coupled at pivots 960 and
963 to the third and fourth links 955 and 957.
[0244] In operation, the lead screw is rotated to either draw in or
push out the blade arms 969A and 969B in a parallel fashion.
[0245] Referring to FIGS. 66-70, a self-aligning access platform
260 comprises blades 261 and 262 that are mounted to blade arms 263
and 264, respectively, and include tissue retractors 280 and 281
extending therefrom. The blade arms 263 and 264 are pivotally
connected at a pivot 275 and driven apart or together by a drive
mechanism 278. The drive mechanism 278 includes a handle 279
operably coupled to a lead screw 277. First and second links 272
and 273 are pivotally coupled to the blade arms 263 and 264,
respectively, and a drive block 276 threadably carried on the lead
screw 277.
[0246] The blade arms 263 and 264 comprise a branch (shown at 265
in FIG. 68) that extends upwardly from the blades 261 and 262 to an
elbow (shown at 282 in FIG. 68) where the blade arms 263 and 264
bend and extend away from the blades 261 and 262. The blade arms
263 and 264 narrow down to a thin section at flexures 289 and 290
adjacent the blade arm elbows. Thin elongated tension members 266
and 267 extend between the drive member 278 and the blade arm
elbows in a spaced relation with the blade arms 263 and 264. The
tension members 266 and 267 include knuckles 268 and 269 coupled to
the blade arms 263 and 264 at pivots 270 and 274. Thin flexures 288
and 291 are formed at the intersection between the tension members
266 and 267 and the blade arm elbows. As the drive member is
operated to spread the ribs apart, the blades 261 and 262 will
advantageously flex about flexures 288 and 289 and 290 and 291,
respectively, to compensate for the alignment of the blade arms 263
and 264 relative to the retracted ribs.
[0247] Alternatively, blades 261 and 262 are coupled to the blade
arms 263 and 264 which have V-shaped mounts 286 and 287 with
opposing flexures 288 and 289, 290 and 291, respectively. As the
ribs are separated, the blades 261 and 262 will flex at flexures
288, 289, 290 and 291 and, thus, advantageously apply a force at
the center of effort through the flexures 288, 289, 290 and
291.
[0248] Referring to FIGS. 71-74, the blades utilized with the
access platform embodiments described herein are preferably
interchangeable from a spreader-type blade to an offsetting-type
blade. In FIG. 71, an elongated vane member 561 folds like a pocket
knife into a slot 562 formed in a spreader blade 560. In FIG. 72,
an elongated member 561 is extensible and flexible. The elongated
member 561 can be hidden substantially within a slot 562 formed in
a spreader blade 560, or extended out the top or bottom of the slot
562 for rib lifting or tissue retraction. The elongated member 561
is flexible in concavity but is prevented by straps or hinges from
flexing in the opposite direction past straight.
[0249] In FIGS. 73 and 74, an offset type blade 565 is shown to
comprise an elongated vane 563 and a recess in the throat area 568
sized to receive a spreader blade 564. A groove 567 is cut into the
offset blade 565 at one end of the recess and a tongue 570
extending from the offset type blade 565 is formed at the other end
of the recess. A tongue 569 extending from the lower portion of the
spreader blade 564 mates with the groove 567 in the offset blade
565. A groove 566 formed in the top part of the spreader blade 564
mates with the tongue 570 of the offset-type blade 565. This tongue
and groove assembly detachably couples the spreader and offset-type
blades together to interchange a spreader blade 564 into an
offset-type blade 565.
[0250] Referring to FIG. 75, a spreader blade 575 comprises
force-tapering (reducing) flexible edges 576 extending outwardly
from either end. The flexible edges 576 are coupled to the spreader
blade 575 via a dove-tail assembly 577. In FIG. 76, a spreader
blade 581 is formed integrally with a tissue retractor 582 to
advantageously allow for automatic tissue retraction. The
un-engaged position of the tissue retractor 582 is shown in phantom
at 583. Once engaged, the tissue forces the tissue retractor 582
upwardly.
[0251] Referring to FIGS. 77-79, a blade 585 comprises a plurality
of access mounts 586 formed integrally in the back side of the
blade 585. A number of different surgical tools such as a
stabilizer 587, malleable shaft blower 588, a flexible blower 589
and hose 590, a suction boot 591, a clip 592, or a light source 593
can be retained in the access mounts 586 of the blade 585 to
facilitate use of these instruments during a surgical procedure in
a minimally sized access area in the patient's chest. In addition,
retaining the surgical instruments in these access mounts 586
advantageously eliminates the need for additional sets of hands in
the surgeon's working space.
[0252] Similarly, in FIG. 80, a double clip 592 is attached to a
stem 594 which is coupled via a mount 595 with a lever 596 to a
blade arm 340 of an access platform 310 described in regard to FIG.
23. The double clip 592 is positioned within the working space to
hold the IMA and eliminate the need for another set of hands in the
working space. Alternatively, as shown in FIG. 81, a shaft 597 of
the mount 595 can be screwed into the intermediate mounting block
490. A stem 594 extends from the mount 595 to a single clip 592.
The shaft 492 of the intermediate mounting block 490 is in turn
screwed into a port such as the port 354 in the blade arm 338 of
the access platform 310 in FIG. 80. The intermediate mounting block
490 advantageously includes input ports 493 and 494 for suction,
aeration, electrical power, etc. Output lumens 495 and 496 with
plugs 497 and 498 are coupled to the mounting block 490 to access
the electrical power, suction or aeration, etc. for an attached
surgical tool.
[0253] In FIG. 82, a mirror 599 extends on a malleable shaft 598
from a mount 596 that is coupled to a blade arm 705 of an access
platform 700 previously described herein with regard to FIG. 33. In
addition, a light source 593 is coupled to the malleable shaft 598
by a clip 499 to direct light toward the mirror 599 to further
illuminate the working space within the patient's chest. The light
593 is advantageously positioned out of the critical cone of
operation.
[0254] Referring to FIG. 83, a light source 484 is coupled to a
light panel 483 that is mounted on a superior blade 480 and a blade
arm 481 which is pivotally coupled to a sternal pad arm 482. The
light panel 483 is used to illuminate the working space created by
the superior blade 480 and inferior blade 485. The light panel 483
may preferably include a contoured surface 486 to direct the light
as noted by directional arrows 487 (see FIG. 84).
[0255] Turning to FIG. 85, a blade 500 includes a horizontal
dove-tail slot 503 extending the length of the back side of the
blade 500. A slide 506 includes a tail 507 slidably received in the
slot 503. A connector 509 of a surgical tool is detachably received
in a vertical dove-tail slot 502 cut into the slide 506. The
connector 509 includes a push button 505 that acts to lock the
slide 506 in place along the horizontal bevel slot 503 and
electrically couple the connector to the embedded electrical source
504 that extends along the back side of the blade 500.
[0256] In FIG. 86, a blade arm 501 connected to a blade 500
includes a universal port 513 which provides access to sources of
electrical power, aeration, suction, etc. A universal plug 514 on
the end of a surgical tool couples to the universal port 513. An
on/off lock-in switch 512 is provided on the blade arm 501 to
either open or close access to the sources of electrical power,
suction, aeration, etc. and/or lock the universal plug 514 in the
universal port 513.
[0257] Referring to FIG. 87, an access platform 995 includes a
suture holder 998 connected to the blade arms 996 and 997. The
suture holder 998 is preferably made from felt, foam, or rubber, or
any other material that will substantially not shed particulates.
The suture holder 998 includes an internal stiffener 999 to drape
the suture holder 998 about the access area in the patient's chest.
The suture holder 998 facilitate suturing during a surgical
procedure.
[0258] The embodiments of the access platform and accessories
described herein are preferably first bulk sterilized and packaged
in a container completely enclosing the access platform and its
accessories, wherein the container prevents microorganisms from
reaching the access platform. Alternatively, the access platform
and accessories would be sterilized after enclosing the access
platform in the container. Methods of sterilization could include
gamma radiation.
[0259] When packaged in this manner, the surgeon can withdraw the
access platform ready-for-use in the surgical procedure and operate
the access platform in a manner described herein.
[0260] While the above description contains many specificities,
these should not be construed as limitations on the scope of the
invention, but rather as an exemplification of one preferred
embodiment thereof. Other variations are possible.
[0261] Accordingly, the scope of the present invention should be
determined not by the embodiments illustrated above, but by the
appended claims and their legal equivalents.
* * * * *