U.S. patent application number 11/312687 was filed with the patent office on 2006-05-11 for surgical retractor with mounting rail.
Invention is credited to Raymond Cartier, Anthony Paolitto.
Application Number | 20060100487 11/312687 |
Document ID | / |
Family ID | 25475387 |
Filed Date | 2006-05-11 |
United States Patent
Application |
20060100487 |
Kind Code |
A1 |
Cartier; Raymond ; et
al. |
May 11, 2006 |
Surgical retractor with mounting rail
Abstract
A retractor assembly for retracting a surgical incision in a
patient, having a plurality of perimeter mounting rails. The
retractor having first and second generally opposed spreader arms
movable relative to each other along a guide member connected
thereto, through the actuation of a drive mechanism. Each of first
and second spreader arms having respectively a first and second
blade portion adapted to retract opposing edges of a surgical
incision. The first and second spreader arms and guide member are
provided with a mounting rail configured and sized for selectively
mounting an instrument-positioning member thereto. The
instrument-positioning member is adapted to cooperatively engage
mounting rail on either of spreader arms or rack bar and is
slidable along a length of the mounting rail when it is in an
loosened configuration and adapted to resist any movement along the
mounting rail when it is in a locked configuration.
Inventors: |
Cartier; Raymond; (Montreal,
CA) ; Paolitto; Anthony; (Montreal, CA) |
Correspondence
Address: |
Anthony PAOLITTO;CORONEO, Inc.
Suite 514
9250 Avenue du Parc
Montreal
QC
H2N 1Z2
CA
|
Family ID: |
25475387 |
Appl. No.: |
11/312687 |
Filed: |
December 21, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10662463 |
Sep 16, 2003 |
7014609 |
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11312687 |
Dec 21, 2005 |
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09877046 |
Jun 11, 2001 |
6648818 |
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10662463 |
Sep 16, 2003 |
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09482052 |
Jan 13, 2000 |
6273853 |
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09877046 |
Jun 11, 2001 |
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08940766 |
Sep 30, 1997 |
6102854 |
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09482052 |
Jan 13, 2000 |
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Current U.S.
Class: |
600/232 |
Current CPC
Class: |
A61B 17/06061 20130101;
A61B 17/0206 20130101; A61B 1/32 20130101; A61B 2017/0496 20130101;
A61B 17/02 20130101; A61B 2017/0243 20130101; A61B 2017/00252
20130101 |
Class at
Publication: |
600/232 |
International
Class: |
A61B 1/32 20060101
A61B001/32 |
Claims
1. A retractor assembly for retracting a surgical incision in a
patient, said retractor assembly comprising: a generally elongated
guide member, said guide member having a guide member mounting rail
extending along a length thereof; a first spreader arm and a second
spreader arm, said first and second spreader arms being
mechanically coupled to said guide member; said first and second
spreader arms being movable relative to each other along said guide
member between a first position wherein said first and second
spreader arms are in a generally adjacent relationship relative to
each other and a second position wherein said first and second
spreader arms are in a generally spaced apart relationship relative
to each other; a first retractor blade and a second retractor blade
respectively extending from said first and second spreader arms,
said first and second retractor blades respectively defining a
first and a second blade contacting surface for respectively
engaging opposed body tissue edges of said surgical incision during
retraction thereof; at least an arm section of said first or second
spreader arms having a spreader arm mounting rail extending along a
length thereof; an instrument-positioning member operatively
coupled to either one of said spreader arm mounting rails or guide
member mounting rail, said instrument-positioning member being
moveable between a loosened configuration and a locked
configuration wherein respectively; in said loosened configuration
said instrument-positioning member is slidable along said mounting
rail; and in said locked configuration, said instrument-positioning
member resists any movement relative to said mounting rail.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of cardiac
surgery instrumentation and more specifically to the surgical
method and apparatus optimized for coronary bypass operations.
BACKGROUND OF THE INVENTION
[0002] Direct coronary artery revascularization on a beating heart
was conducted, both experimentally and clinically, in the 1950's
and the 1960's, without stabilization.
[0003] Challenges associated with this surgical technique are as
follows: [0004] complete anastomosis is very difficult to achieve
due to the motion of the beating heart; [0005] the technique is
limited to vessels of a minimum diameter--again due to difficulty
in the anastomosis technique on a beating heart; [0006] lifting of
the heart for revascularization of posterior arteries results in a
precipitous drop in arterial pressure; [0007] the learning curve
for surgeons performing this technique is very high, negotiating
the learning curve may represent significant surgical morbidity and
mortality.
[0008] The development of the cardio-pulmonary machine for
extracorporeal circulation (ECC) enables coronary operations on an
arrested heart. This allows the surgeon to operate on a perfectly
still heart and to manipulate the heart to expose the target
artery.
[0009] At the present time, the standard coronary artery bypass
graft (CABG) procedure typically requires a full median sternotomy
and extracorporeal circulation through a cardio-pulmonary
machine.
[0010] Even with the constant technological improvements achieved
during the last twenty-five years, the advantages offered with ECC
have been offset by morbidity and mortality related to the ECC
itself. The inflammatory response, as well as systemic
microembolisms generated by ECC, induce to some extent a
dysfunctional state of the brain, lungs and kidneys, which tends to
increase with the aging of the patient. Furthermore, evidence
suggests that when ECC can be avoided, the left ventricular
function is better preserved, thereby reducing risk of
post-operative complications.
[0011] As a result, alternate CABG procedures that do not rely on
the use of ECC offer distinct advantages.
[0012] Recently, minimally invasive surgery, involving a partial
sternotomy or mini-thorocotomy, has generated much interest since
it removes precisely the need for ECC. This surgery does, however,
have its limitations. It is adequate for only one or two coronary
bypass grafts. Moreover, it does not provide access to the
posterior descending or circumflex arteries, and impairs both the
anastomosis and the surgeon's vision due to the limited heart
exposure.
[0013] These limitations may lead to future, more-invasive surgical
interventions through partial or full sternotomy, if "blockages"
progress in those arteries which were not accessible via minimally
invasive procedures.
[0014] Therefore, partial revascularization may lead to
re-intervention which not only represents a disadvantage to the
patient but a financial burden to the health care system.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of the present invention to
provide a surgical apparatus allowing to perform coronary surgery,
in particular coronary artery revascularization, without the need
for extra-corporeal circulation.
[0016] It is a further object of the invention to provide a
surgical apparatus to perform complete revascularization of
coronary arteries without the need for extra-corporeal
circulation.
[0017] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, on a beating heart
[0018] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, enabling grafting on all
arteries of the heart and their respective branches, most
particularly the right coronary (RC), the posterior descending
artery (PDA), the left anterior descending artery (LAD) and
diagonals, the branches of the circumflex artery (Cx) namely the
obtuse marginal (1 through 4) and the postereo-lateral
branches.
[0019] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, provided with positioning means
being capable of being mounted in a plurality of locations on a
sternum retractor or any other adequate support.
[0020] It is a further object of the invention to provide a
surgical a for performing coronary surgery, in particular coronary
artery revascularity, simplifying the grafting process.
[0021] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, with reduced costs associated
with shorter time of surgery, reduced costs of surgical equipment,
reduced surgical staff, significantly reduced risk of medical
complications, and shorter hospital recovery stay.
[0022] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, that is easy to utilize for
surgeons and representing an evolution of current proven practice
without the need for long retraining period.
[0023] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, enabling surgeons to operate on
all patients, especially those not well suited to minimally
invasive techniques or well suited to conventional coronary artery
bypass grafting (CABG) with extra corporeal circulation (ECC).
[0024] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, with a risk reduced procedure
for the patient, a cost effective solution to reducing health care
expenses, and an ergonomic layout enhancing the efficiency of
surgeons.
[0025] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, that is ergonomic, easy to
deploy, easy to sterilize, and time efficient with respect to the
multitude of attachments which might be needed during the course of
open chest surgery.
[0026] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, which optimizes accessibility to
all different arteries requiring grafting irrespective of
variations in personal physiology from one patient to another.
[0027] It is a further object of the invention to provide a
surgical apparatus for performing coronary surgery, in particular
coronary artery revascularization, that can be used with known
types retractors, as a retrofit arrangement.
[0028] Another object of the invention is to provide positioning
means for a surgical apparatus, in particular a heart stabilizer
for performing coronary surgery, particularly coronary artery
revascularization, without the need for extra-corporeal
circulation.
[0029] Another object of the invention is to provide contacting
means for a surgical apparatus, in particular a heart stabilizer
for performing coronary surgery, particularly coronary artery
revascularization, without the need for extra-corporeal
circulation.
[0030] Another object of the invention is to provide a sternum
reactor for performing coronary surgery, particularly coronary
artery revascularization, without the need for extra-corporeal
circulation.
[0031] As embodied and broadly described herein, the invention
provides a surgical apparatus for coronary surgery on a patent
comprising contacting means being capable of providing a mechanical
force against at least a portion of the patient's coronary organs
according to its positioning with regard to said organs,
positioning means to set said contacting means in a given
substantially stable spatial position and orientation within a
given volume, said contacting means being pivotingly connected to a
sternum retractor via said positioning means.
[0032] This surgical apparatus enables performing coronary surgery,
particularly coronary artery revascularization, without the need
for extra-corporeal circulation. That is to say, the operation can
be realized on a beating heart. There is no need to use a
cardio-pulmonary machine, which considerably reduces the costs of
the operation. Without extracorporeal circulation, mortality and
morbidity rates are also reduced.
[0033] The surgery and graft process can be performed by only one
surgeon and one assistant, as opposed to standard coronary artery
bypass graft surgery which usually requires two surgeons and a
perfusionist for ECC.
[0034] As embodied and broadly described herein, the invention also
provides positioning means for a heart stabilizer for use in
coronary surgery, said heart stabilizer comprising contacting means
intended to provide a mechanical force against at least a portion
of the patient's coronary organs according to is positioning with
regard to said organs, said positioning means being intended to set
contacting means in a given substantially stable spatial position
and orientation within a given volume and being connectable in at
least one location to a sternum rector, said contacting means being
connectable to a movable free portion of said positioning
means.
[0035] The contacting means can therefore be positioned in an
almost unlimited number of positions and orientations to facilitate
the intervention on any artery. This also brings high flexibility,
as any patent whatever the morphology may be, can be treated.
Moreover, the adaptability of the apparatus facilitates the
grafting process. For example, the right coronary artery is most
accessible when the positioning means are mounted on the rack bar.
The left anterior descending artery and diagonal arteries are most
accessible when positioning means are mounted in the ending portion
of the spreader arms. Access to the circumflex artery and posterior
descending artery is enhanced when positioning means are mounted on
the right side of the retractor, patient's view.
[0036] Preferably, the positioning means comprise a sliding member
providing relative movement between said sternum retractor and said
positioning means. This provides great flexibility and facilitates
the surgical manipulations.
[0037] As embodied and broadly described herein, the invention also
provides positioning means for a heart stabilizer for use in
coronary surgery, said heart stabilizer comprising contacting means
intended to provide a mechanical force against at least a portion
of the patient's coronary organ according to its positioning with
regard to said organs, said positioning means being intended to set
contacting means in a given substantially stable spatial position
and orientation within a given volume and being connectable in at
least one location to a sternum retractor, wherein said positioning
means comprise an articulation member for providing displacement of
a member connected thereof with at least one degree of freedom, a
positioning rod connectable to said articulation member, said
contacting means being connectable to said positioning rod.
[0038] More specifically, under this preferred embodiment, the
positioning means comprise a second articulation member for
providing displacement of a member connected thereof, with at least
one degree of freedom, said positioning rod being connectable to
said second articulation member. The articulation member can
advantageously be made of a resilient material.
[0039] In a specific example, the articulation member comprises at
least one partly spherical member pivotingly maintaining a
positioning rod member between two hollow cylindrical bodies. In
another specific example, the articulation member comprises at
least one partly spherical member pivotingly maintaining
positioning rod member between two clamping members.
[0040] In another specific example, the "quick-assembly" parts
allow the positioning means to be placed in at least six different
orientations with respect to the sternum retractor, and
consequently the patient's heart: four orientations along the
perimeter of the retracted chest cavity, and two cross-corner
diagonal orientations. This maximizes the options for optimum
accessibility to the target artery. It also provides the surgeon
with flexibility during delicate surgical asks like suturing, as he
has access to strategic sections of the chest cavity that are free
from all devices.
[0041] As embodied and broadly described herein, the invention also
provides positioning means for a heart stabilizer for use in
coronary surgery, said heart stabilizer comprising contacting means
intended to provide a mechanical force against at least a portion
of the patient's coronary organs according to its positioning with
regard to said organs, said positioning means being intended to set
contacting means in a given substantially stable spatial position
and orientation within a given volume and being connectable in at
least one location to a sternum retractor, wherein said positioning
means further comprise an articulation member for providing
displacement of a member connected thereof with at least one degree
of freedom, a positioning rod connectable to said articulation
member, a second articulation member for providing displacement of
a second member connected thereof with at least one degree of
freedom, a second positioning rod connectable to said second
articulation member, said contacting means being connectable to
said second positioning rod.
[0042] As embodied and broadly described herein, the invention also
provides contacting means being capable of providing a mechanical
force against at least a portion of the patient's coronary organs
according to its positioning with regard to said organs within a
given volume and comprising two substantially elongated contacting
arms defining therebetween an arterial window.
[0043] As embodied and broadly described herein, the invention also
provides a sternum retractor for use in coronary artery surgery,
comprising: a rack bar extending transversally between the ending
portions of a fixed spreader arm and a movable spreader arm, these
arms both extending longitudinally in a direction substantially
normal with regard to the rack bar, said movable arm being capable
of being displaced along the rack bar and said spreader arms being
provided with blades, contacting means intended to provide a
mechanical force against at least a portion of the patient's
coronary organs according to its positioning with regard to said
organs, positioning means intended to set contacting means in a
given substantially stable spatial position and orientation within
a given volume and being connectable in at least one location to a
sternum retractor said contacting means being connectable to a
movable free portion of said positioning means.
[0044] All interfaces are intended and designed to keep the open
chest cavity as ergonomic and accessible as possible, free from all
peripheral tubing and connectors. All interfaces, design features
and components are easy to sterilize.
[0045] The surgical equipment described herein can be used to
perform multiple revasculariations on any of the coronary arteries
or branches without repositioning the sternum retractor after
initial deployment. The interfaces between the positioning means
and the retractor are preferably designed to permit retractor
spreader arm readjustment without disconnecting the positioning
means setup. It can be used to perform multiple revasculariations
by surgeons experienced in standard on-pump CABG with minimal
training. It also can be used to perform revasculariations for both
initial surgeries and reoperative cases.
[0046] The surgical equipment described herein provides the surgeon
with visibility equal to that of standard CABG. Furthermore, in
cases where unforeseen complications develop during surgery, the
method described herein is not disadvantaged with the delays and
complications associated with conversion from a minimally invasive
CABG technique to full open chest surgery in cases. It is also not
required for the patient to be placed on single lung ventilation,
as is the case in some minimally invasive techniques.
[0047] The surgical apparatus described herein reduces the costs
associated with standard CABG in particular in the following
specific arm: [0048] a cardio-pulmonary machine is not required;
[0049] a perfusionist to operate the cardio-pulmonary machine is
not required; [0050] less highly trained surgical staff is required
to preform the surgery (one surgeon and assistant, compared to two
surgeons); [0051] reduced hospital stay is required be ECC is not
used; [0052] reduction in frequency of complications and associated
costs; [0053] reduction in operating time due to ergonomic design
features of apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] The invention will further be described, by way of example
only, with reference to the accompanying drawings wherein:
[0055] FIG. 1A is a perspective view illustrating a first
embodiment of the surgical apparatus according to the
invention;
[0056] FIG. 1B is a perspective view illustrating working volume W
and motion degrees of freedom of the surgical apparatus according
to the invention;
[0057] FIG. 2 is a top view of the embodiment illustrated in FIG.
1A;
[0058] FIG. 3 is an exploded view of the first articulation member
used in FIG. 1A;
[0059] FIG. 4A is an exploded view of FIG. 1;
[0060] FIG. 4B is a cut away view of the articulation member
illustrated in FIG. 4A;
[0061] FIG. 4C is a side elevational view of the knob of
articulation member illustrated in FIG. 4B;
[0062] FIG. 5A is a perspective view illustrating a second
embodiment of a surgical apparatus according to the invention;
[0063] FIG. 5B is a perspective view (party cut away) of the
articulation members used in FIG. 5A;
[0064] FIG. 6 is a side elevational view of the embodiment
illustrated in FIG. 5A;
[0065] FIG. 7 is a variant of the embodiment in FIG. 5A;
[0066] FIG. 8 is another variant of the embodiment of FIG. 5A;
[0067] FIG. 9 is a variant of the embodiments of FIG. 1A and FIG.
5A;
[0068] FIGS. 10A to 10F are perspective views according to the
invention;
[0069] FIG. 11 is another embodiment of the surgical apparatus;
[0070] FIG. 12 is a perspective view of a sternum retractor
variant;
[0071] FIGS. 13A to 13F illustrate examples of several setting
possibilities of the positioning members on a sternum retractor, as
illustrated an FIG. 12;
[0072] FIG. 14 is a perspective view partly exploded and
schematically illustrating an example of a retrofit system
according to the invention;
[0073] FIGS. 15A to 15F illustrate several examples of support
members for retrofit systems according to the invention, as
illustrated in FIG. 14;
[0074] FIG. 16 is a perspective view illustrating a further
embodiment of the surgical apparatus according to the invention,
using easy to connect/disconnect articulation members;
[0075] FIG. 17 is a fragmentary top view of a sternum retractor
according to the invention;
[0076] FIGS. 18A to 18C are examples of variants of the embodiment
described in FIG. 5A;
[0077] FIGS. 19 and 20 illustrate variants of the embodiment of
FIG. 1A;
[0078] FIGS. 21A to 21D illustrate further variants of the
embodiment of FIG. 1;
[0079] FIG. 22A is a perspective view of a sternum retractor
illustrated in FIG. 1A; FIGS. 22B-22F illustrate examples of rail
profiles used on a sternum retractor illustrated in FIG. 22A;
[0080] FIGS. 23A and 23B illustrate perspective views of the
surgical apparat according to the invention, in use during a
coronary artery revascularization;
[0081] FIG. 24 illustrates a push type configuration according to
the invention;
[0082] FIG. 25 illustrates a pull type configuration according to
the invention;
[0083] FIGS. 26 to 29 illustrate perspective views of contacting
means according to the invention;
[0084] FIGS. 30A to 30G illustrate variants of contacting means
provided with different types of attachment means;
[0085] FIGS. 31A to 31F illustrate variants of contacting means
provided with dissent types of textures;
[0086] FIG. 32 illustrates a variant of a positioning rod.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0087] The surgical apparatus according to the invention is
provided to be used with a sternum retractor. Single purpose
sternum retractors, which only serve to retract the patient's
sternum and ribcage, are well known in the art. They are mainly
used for retracting the mediastinum in order to person coronary
artery revasculatizations, heart valve replacement, and other
cardiac intervention.
[0088] Such a sternum retractor 1 comprises a rack bar 2 extending
transversally, a fixed spreader arm 3, and a movable spreader arm
4. Both arms extend longitudinally in a direction substantially
normal with regard to the rack bar. The movable arm 4 can be
displaced along the rack bar, using a crank 5 activated by a pinion
mechanism (not shown) through shaft 6. Two blades 7 are provided
underneath the spreader arms.
[0089] This invention introduces an improved retractor specifically
designed to provide attachment interfaces for a variety of
positioning means and any other equipment used during the course of
open chest cardiac surgery.
[0090] In broad terms, the surgical procedure ad to this invention
consists of: [0091] 1. Full or partial sternotomy; [0092] 2.
Isolation and removal of either internal saphenous vein(s) or of
internal thoracic artery(ies); [0093] 3. Strategic positioning and
manipulation of beating heart with regard to the artery to be
bypassed; [0094] 4. Locally immobilizing and stabilizing the
portion of the beating heart around the grafting site; [0095] 5.
"Pinching" the target artery upstream and downstream of occluded
site to restrict blood flow during grafting; [0096] 6. Grafting of
bypass veins and/or arteries; [0097] 7. Verifying blood flow
through newly grafted bypass artery; [0098] 8. Draining of chest
cavity; [0099] 9. Closing of chest cavity.
[0100] In the course of an operation, a surgeon needs to perform
certain tasks within the volume defined by the rack bar 2, the arms
3 and 4 and the chest cavity, such as reaching the target arteria,
suturing, etc. The volume in which the surgeon needs to perform
these different tasks, will be called herein the working volume W.
This volume also comprises a buffer zone extending beyond the
perimeter of open chest cavity (see FIG. 1B). The present invention
provides positioning means 20 allowing the surgeon or an assistant
to place and secure a specific surgical instrument, namely the
contacting means 30, within this working volume, to perform
revasculatizations on a beating heart more easily, quickly and do.
The above mentioned type of retractor is preferably used to set the
positioning means. However, other retractor types, for example
chest rector or thoratic retractor, or other supports, for example
a bed or a crane, can also be used.
[0101] FIG. 1A illustrates a first embodiment in which the
positioning means comprise a unique articulation member. FIG. 1B
schematically depicts the flexibility and versatility of the
surgical apparatus through the motion degrees of freedom listed
below: [0102] S displacement of articulation member 50 along rails
40 of reactor; [0103] R1 axial displacement along centerline of
first positioning rod 60 through articulation member 50; [0104] R2
displacement along centerline of second positioning rod 70 through
articulation member 80; [0105] .alpha. rotation about centerline of
articulation member assembly 50; [0106] A1 angular displacement
through rotation .alpha.; [0107] .beta. angle between centerline of
first positioning rod 60 and centerline of articulation member
assembly 50; [0108] P1 displacement along z axis achieved through
rotation .beta.; [0109] .epsilon. angle between first positioning
rod 60 and second positioning rod 70 in the plane formed by their
two axes; [0110] .phi. angular rotation of second positioning rod
70 in the plane normal to the centerline of first positioning rod
60; [0111] A2 angular displacement of contacting means 30 about the
centerline of second positioning rod 70.
[0112] The fixed spreader arm and movable spreader arm are
preferably provided with rails 40, disposed axially along said
arms, for example on top of blades 7. Any known type of rail can be
used. FIGS. 22A to 22F illustrate various examples of rail
profiles. Other types can also be used like, for example, a rod
type rail.
[0113] A first articulation member 50 is slidingly and pivotingly
engaged in said rails. This first articulation member is easily
removable from the rails and can therefore be placed on any of the
rails. It can also be set in any axial position on said rails or,
alternatively on the rack bar slot as shown on FIG. 17. This first
articulation member also serves as a support for a first
positioning rod 60. The rod 60 and the articulation member 50 are
arranged to allow the free end portion of the rod to be placed in
any position within said working volume W. This rod 60 can be
easily displaced first with the sliding motion S of the
articulation member 50 along any of said rails 40, corresponding to
a displacement along the Y axis. Secondly, with an angular motion
A1 of the articulation member 50 about its own centerline, the rod
60 can be placed along a given angle .alpha.. Thirdly, the rod 60
can be shifted axially (R1) though the member 50 in order to get
doser or farther from said member. Finally, the member 50 can also
provide a first height positioning P1, allowing the rod 60 to pivot
vertically, to reach a given .beta. angle.
[0114] The ending portion of this first positioning rod within the
working volume is provided with a second articulation member 80.
This second articulation member mainly serves as a holding member
for a second positioning rod 70. One ending portion of this second
positioning rod is provided with a contacting means 30. This second
articulation member allows advantageously further types of
displacements; first, an axial sliding motion R2 to allow the
positioning of the contacting means 30 along the centerline axis of
rod 70, within the working volume W; second, an angular
displacement A2 of a contacting means 30 about the centerline of
positioning rod 70; third, an angular orientation of the second
positioning rod 70 with respect to first positioning rod 60 through
angle .epsilon.; fourth, an angular rotation .phi. of the second
positioning rod 70 in a plane normal to the centerline of the first
positioning rod 60. According to a preferred variant, member 50
provides a coarse adjustment whereas member 80 provides a fine
adjustment.
[0115] In this way, the contacting means can be placed very
accurately in practically any position and orientation within said
volume W. The position is preferably obtained with displacement S,
R1, A1, P1, and R2 The orientation of the contacting means is
mainly achieved with the displacement A1, A2, P1, .phi. and
.epsilon.. Of course, many variants of the invention can be
provided, only by adding or removing a given articulation or
displacement possibility. For example, the first transmission
member 50 could be provided so that rod 60 rotates along its own
axis, or contacting means 30 could be provided with a pivot at its
junction with rod 70, etc. Furthermore, the positioning means
extends advantageously beyond the perimeter of the open chest
cavity.
[0116] Different types of articulations may be used for the first
articulation member 50 and second articulation member 80. For
example, known types of articulations like resilient articulations
or spherical bearing articulations, etc., may be used without
departing from the spirit of the invention. The articulations used
with the embodiment illustrated in FIG. 1A are shown in details in
FIGS. 3 and 4A.
[0117] FIG. 3 illustrates an exploded view of an example of a first
articulation member, such as the one used in the embodiment of FIG.
1, with reference 50. A hollow cylindrical body 55 is provided
along its longitudinal wall with two opposite oval windows 551. A
top cover 552 on the upper end is provided with a central aperture
553. A bottom hollow cylindrical member 52 is provided with two
opposite lateral openings 522. The front portion is open to
cooperate with other components. The inner top and bottom portions
are shaped with opposite concave profiles 524 and 523. Two opposite
semi-sphere like adaptors 56 and 54 are provided with a cylindrical
hollow. A top hollow cylindrical member 53 is provided with lateral
openings 531 corresponding substantially to those of the hollow
cylindrical member 52 so that it can cooperate with the bottom
member 52. On top of member 53 a screw member 533 is provided. The
inner bottom portion is shaped with a concave profile corresponding
to the lower semi-sphere like adaptor. The positioning rod is
engaged through the hollow portion of the two semi-sphere like
adaptors to create an assembly.
[0118] This assembly is placed in the cavity formed by the
cooperating members 52 and 53. The upper and lower adaptors 56 and
54 cooperate respectively with the concave inner portion 524 and
the concave inner portion 532. This allows easy pivoting of the
rod, not only vertically, but also laterally. All these components
are maintained together in the cylindrical body 55. The rod extends
through windows 551. Screw member 533 extends through aperture 553
and cooperates with set screw 51. A flange 521 provided at the
bottom of member 52 allows easy engagement of the assembly within
rails 40 or any attachment means, that do not necessarily provide
sliding possibilities.
[0119] When the set screw is loose, cooperating components allow
pivoting movement of the rod and eventually a rotational movement
of the latter along its own axis. When the screw is tightened, a
compression stress is generated with the inner portion 532 of
member 53 pressing against adaptors 54 and 56 and inner portion 524
of member 52. A tight fit is therefore created into the cylinder
body 55. This mechanical stress avoids any relative movement of the
components. Moreover, the body 55 is pressed against the spreader
arm or rail or the like on which it is engaged, creating a locking
effect. The articulation is then slidingly and pivotingly
locked.
[0120] FIGS. 4A to 4C illustrate views of an example of an
articulation member such as the one used in the embodiment of FIG.
1, with reference 80. The figures shows two elongated and opposite
clamping members 82, each one provided with an inner seat portion
83 to cooperate with a ball end 61 on rod 60, and an apexes 84 for
engagement of set screw member 81. An inner annular groove 85 is
also provided for engagement of the second positioning rod 70. The
85 is arranged in a direction substantially perpendicular with
regard to the longitudinal axis of the clamping members 82. A
preload spring 62 ensures that the members 82 and 61 are property
maintained as an assembly. Moreover, the two members 82 are
tightened together with screw member 81.
[0121] They provide a housing for ball end 61 and a portion of rod
70. Depending on the tightening of screw member 81, the
articulation maintains the rods 60 and 70 in a locked or mobile
arrangement The angular movements .epsilon. and .phi. of
positioning rod 70 are achieved through relative movement of
members 82 with respect to 61. Screw member 81 is preferably
provided with an arrangement that gives the possibility to adjust
the positioning by using either side of screw member 81. This
feature is advantageous because the working area W is in general
very small and the access to a specific side of the screw member 81
is limited for the surgeon.
[0122] FIGS. 4B and 4C illustrate such an arrangement Left side
knob 801 extends longitudinally with threaded rod 802 through the
left damping member 82 and is screwed to the right damping member
which is provided with inner thread 806. The end portion of rod 802
and the corresponding inner portion of knob 801 are shaped with two
opposite flat surfaces 803, allowing torque transmission from the
knob to the rod. Locking balls 805 provided in a circular groove in
the inner portion of right side knob and maintained with a set
screw 804 keep the components together. With such an arrangement,
the surgeon tightens or untightens the two clamping members 82 by
actuating any of the two knobs 801. The rotational movement allows
inner threads 806 to create a translational movement of
corresponding right clamping member 82, that will therefore get
closer or farther from the other facing damping member, resulting
in a tightening and loosing effect.
[0123] With these various adjustment possibilities, the contacting
means 30 can easily be positioned very accurately with regard to
the target arteria of the heart. Moreover, according to a variant,
a coarse adjustment is performed with one articulation member (for
instance the first articulation member 50) and a fine a adjustment
is achieved with the other articulation member (for instance the
second articulation member 80).
[0124] FIG. 5A illustrates a second preferred embodiment according
to the invention. The sternum retractor arrangement is similar to
the previously described one. However, the positioning means 20
slightly differs from the first embodiment According to this second
embodiment, two articulation members 150 and 250 are provided.
These articulations may be in many aspects similar to those
described above.
[0125] FIG. 5B is a perspective view, partly cut away, illustrating
the articulation members 150 and 250, and the first positioning rod
60. One articulation member is arranged to allow a sliding movement
of the positioning rod through it. An inner rod member 151 is
provided with a transversal hole 152 seated in a hollow cylindrical
body 153, with two open ends 156. A treaded portion 155 extends
upwardly beyond the body for engagement with a set screw 51. The
bottom portion extends downwardly beyond the body and is provided
with a flange 154 for engagement with rails 40.
[0126] When set screw 51 is tightened, a tensile strain causes the
bottom edge of the cylinder body 153 to press against the edge of
windows 156 through which rod 60 extends. The same strain causes
the bottom edge of the cylinder body 153 and the upper edge of
flange 154 to press against the rails 40 in opposite directions.
The assembly is therefore locked. When set screw is loose, no
strain acts against the components. The rod can slide through the
articulation and the articulation is capable of sliding and/or
pivoting along the rails. The opposite articulation member 250 can
be similar to the one described above or can be simplified by
having rod 60 in a fixed configuration on relative to articulation
member 250. This can be achieved with an assembly comprising an
inner rod member 151 and a cylinder body 153 similar to those
previously described. The rod is then attached to the cylinder
body. This allows sliding and/or pivoting movement of the
articulation member 250 along the rail 40. One or both
articulations can be displaced along the rails or placed on
discrete locations on the retractor, if no rails are provided.
[0127] The articulations can be set in a symmetric disposition,
with each articulation having an identical position with respect to
the rack bar. They can also be arranged in asymetrical disposition
on the same arm, etc., as shown in FIG. 13. The translational
motion of the rod 60 through the articulation 150 remains an
advantageous feature of this embodiment. For example, if during
surgery, the sternum retractor opening must be modified, the rod 60
can slide through one of the articulations (for instance, the
articulation engaged in the movable spreader arm), allowing the
second positioning rod 70 and the contacting means 30 to remain in
substantially the same position with regard to the heart. This
allows efficient readjustment of the surgical apparatus without
complete disassembly of the positioning means.
[0128] Of course, with such an embodiment, the second articulation
member 80 is slightly different from the one described above (shown
in FIG. 2). This second articulation member allows advantageously
five types of displacements: first, an axial sliding motion R3 to
allow the positioning of the second rod 70 along the centerline
axis of rod 60; second, an axial sliding motion R4 to allow the
positioning of the second rod 70 through articulation member 80;
third, an angular rotation of the contacting means 30 about the rod
70 axis; fourth, in the plane defined by the axes of the rods 60
and 70, angular orientation of said rods; fifth, angular rotation
of rod 70 around the axis of rod 60. The set screw 81 allows for
easy setting and readjustment of rod 70 with respect to rod 60. The
contacting means 30 is provided at the end portion of the rod 70,
within the working volume W. The rails 40 can eventually be
extended with a separate rail portion placed on the rack bar.
[0129] FIG. 6 illusbtres a transversal view of this embodiment.
From this drawing, it can be seen that the contacting means 30 has
a very specific shape. In this particular embodiment, the slightly
curved profile allows the positioning of the contacting means with
regard to the heart, so that the heart is placed in the concave
side of the contacting means. With such an arrangement, the
positioning means is capable of producing a pulling force against
the heart. These features will be described thoroughly herein
below.
[0130] FIG. 7 shows a variant of the previous embodiment. According
to this variant, the rod 60 is bent to form a U-shape with regard
to the two articulation members. Such a shape gives additional
adjustment possibilities to position the contacting means with
regard to the heart.
[0131] FIG. 8 illustrates a further variant of the embodiment
illustrated in FIG. 5A. According to this variant, the rod 60 is
shaped in the form of a circular arc. The letter "R" on the figure
illustrates the radius of the corresponding virtual circle. Once
again, this particular shape allows a very accurate positioning of
the contacting means with regard to the target artery.
[0132] FIG. 9 illustrates a top view of a variant whereas one or
both blades 7 are rotatably mounted on the retractor arms. The
remaining features being similar to those already described are not
illustrated. This variant is advantageous while it gives a
possibility to adapt the blade arrangement to the sternum of the
patient to be treated, without affecting the remaining components
of the apparatus. For example, one blade could be installed
slightly rotated with regard to the other one.
[0133] According to the invention, the surgical apparatus
advantageously provides anchoring means disposed in discrete
positions along the arms 3 and 4 or possibly at any other location
on the device. FIGS. 10A through F illustrate different variants of
such anchoring means. These anchoring means serve many purposes,
for example to attach "in-process" sutures that are strategically
used to position tissue or organs away from primary surgical
operation; to attach Silastic.TM. rubber bands, or silicon loops,
utilized during myocardial mobilization, or pericardial traction;
to attach sutures or silicon rubber loops, serving to "brace" the
positioning means rod in significantly overhung orientations with
respect to the retractor; and to secure any peripheral equipment
used during operation to keep uncluttered chest cavity during
surgery. These anchoring means are intended to allow a quick
assembly and disassembly of the wire, suture, Silastic.TM. rubber
bands, etc.
[0134] FIG. 10A shows an example of an arrangement with such means
preferably disposed along a rail. FIG. 10B illustrates an example
of an anchoring means with a "V" shaped aperture in which the wire
can be inserted very quickly. At the base of the "V", a slightly
enlarged opening provides a seat to lock the wire. Each side of the
"V" shape is provided with a blade, retaining the wire that is
wounded-up around the body of the means.
[0135] FIG. 10C illustrates a different shape of anchoring means
with a nail like head. FIG. 10D illustrates another variant which
is shaped like an inclined rod. FIG. 10E illustrates anchoring
means consisting of T-shape apertures provided in the spreader arm
or in any other location of the surgical apparatus. FIG. 10F
illustrates a pin type anchoring means. As illustrated the pin is
advantageously slidingly arranged.
[0136] FIG. 11 illustrates a third embodiment of a heart stabilizer
according to the invention. This simplified embodiment uses a
standard sternum retractor. The positioning means 20 are connected
to the sternum retractor through an articulation member 250
attachable to the rack bar of the retractor. According to the
embodiment illustrated in FIG. 11, the articulation member consists
of a "U" shaped sliding member, laterally inserted into the rack
bar 2. A set screw 251 allows to lock or unlock the articulation
member on the rack bar. The unlocked position allows the surgeon to
slide the assembly on either side of the bar. It also permits him
to slide the first positioning rod 60 axially. It also allows him
to slidingly and pivotingly set rod 60 with respect to rack bar 2
through articulation member 250. The set screw 251 allows an easy
longitudinally positioning of the assembly.
[0137] The axial positioning can be set either with the
articulation member through set screw 251 or with the second
articulation member 180 through a set screw 181, though this second
articulation member mainly serves to angularly position a second
positioning rod 70. This angular position can be easily modified as
the two clamps are pivotally connected together. The contacting
member 30 is provided at the ending portion of this rod located
within the working volume W.
[0138] The characteristics related to the rods and second
articulation member are similar to the second embodiment
illustrated in FIG. 5A and described above. This very simple
attachment means allows the use of a heart stabilizer according to
the invention with an existing sternum retractor. Such a
"retro-fit" is very advantageous while mast hospitals or clinics
are already equipped with retractors. This existing equipment can
thus be updated. This embodiment can also feature quick
connect/disconnect articulations, as described below.
[0139] FIGS. 12 to 15 illustrate a further embodiment particularity
suited to retrofit applications but not exclusively reserved for
them. A known type sternum retractor 1 may be used. According to
the invention, the retractor is easily modified to provide
attachment means, such as for example attachment holes 8 preferably
located by each end portion of the spreader arms and/or arranged in
discrete locations along the retractor.
[0140] Different types of stabilizer can then be used to complete
the arrangement. For example, a stabilizer with positioning means
such as described above for the embodiments of FIG. 1A or 5A The
attachment means could serve to attach rails, that for example are
similar to those of FIGS. 1 or 5, or an assembly without rails, the
articulation member being attachable to any of the retractor holes
8.
[0141] FIGS. 14, 15, and 16 illustrate examples of attachment 100
to the retractor 1. FIG. 14 shows an example with two supports onto
which the rail is attached. The rail could be of a rod type, as
shown in FIG. 14, or sliding type as shown in FIG. 1A, or any other
appropriate type. FIG. 15A illustrates an example of a support
provided with a rubber boot 101, a rod 102, and a locking system
actuated by a cam-lock. The system is illustrated in the locked
mode, in which the rubber expansion fills the surrounding cavity
creating thus a locking effect.
[0142] FIG. 15B illustrates a magnetic type of support which offers
the advantage to avoid the holes on the retractor in the previous
examples. The holes are replaced by a magnetic insert 111, on which
the magnetic support can be placed. The magnetic support 110
preferably comprises a layer arrangement with alternate layers of
magnetic 112 and nonmagnetic 113 alloy. A portion of the layer
assembly is transversally movable with regard to the remaining
portion. Buttons 114 allow the surgeon or user to set the assembly
onto the retractor by placing the two portions in magnetized or
unmagnetized positions.
[0143] FIG. 15C illustrates a threaded type support which can
easily be set using conventional tooling. FIG. 15D illustrates a
spring loaded ball bearing type support adjustable in a locked or
unlocked position depending on the lateral position of the balls.
The figure illustrates the locked mode, in which the balls are
projected and maintained in a locking arrangement by cooperating
with a grooved portion of the retractor. In the unlocked position,
the groove is free and the support can be removed. FIG. 15E
illustrates a hydraulic deployment arrangement. A set screw acts on
a piston arrangement which can cause a lateral flexible membrane
expansion or retraction under the effect of an inner oil pressure
increase or decrease respectively. FIG. 15F illustrates a
mechanical wedge type support.
[0144] The above variants are only examples of attachment means
that could be provided. Other types of variants may be used,
without departing from the spirit of the invention.
[0145] According to the invention, the positioning means could be
positioned at least in six different orientations with respect to
the sternum retractor, and consequently the patient's heart (see
FIGS. 13A to 13E illustrating examples of rail configuration): four
orientations along the perimeter of the retracted chest cavity, and
two cross-corner diagonal orientations. This maximizes the options
for optimum accessibility to the target artery. Of course,
according to the respective longitudinal position of the
articulations along the arms, a plurality of other positions is
also possible. Furthermore, if two rails are used, the
possibilities will still be increased.
[0146] FIG. 16 shows a variant with easy to connect/disconnect
positioning means. Such a variant could be used with any
embodiment, with or without rails. A resilient clip assembly 300 of
known type could be provided. Such an arrangement enables the
surgeon to place the contacting means with more flexibility and
allows an easier access to the working volume, which is in general
a small volume, difficult to access as many complex instruments
obstruct the cavity. This embodiment allows easy access without
having to proceed to many adjustments; these adjustments are
advantageously performed after the contacting means are well
placed. The figure also illustrates an example of rod type rails on
which an annular articulation can be slidingly placed. The quick
assembly/disassembly function can also be achieved via variety of
interfaces (cam-type locking devices, toggle devices, screw type
devices, mechanical magnets, etc.).
[0147] FIG. 17 shows a variant in which the positioning means, and
namely the articulation member, are attached to the sternum rector
via a slot provided on the rack bar. Such a slot can be realized on
an existing retractor, resulting in a retrofit arrangement. It can
also be provided on a retractor specifically as per the
invention.
[0148] FIGS. 18A to 18C illustrate a variant where the articulation
members 650 are bent in such a way to place the rod member 60
laterally distant from the sternum retractor 1. With such an
arrangement, the working area is of easy access and with enhanced
ergonomy.
[0149] FIGS. 19 and 20 show variants of the embodiment previously
described and illustrated in FIG. 1A. The articulation members and
rods of the embodiment of FIG. 1A are replaced by known-type arms
capable of providing rotation, pivoting and translational motions
or the like. These arms types are similar to those encountered in
desk lamps. These variants are advantageously simple to
manufacture, quick and easy to adjust Other variants offering
similarities to these ones can also be provided, sometimes with
less positioning capabilities, for example without rotation,
without pivoting movement, etc.
[0150] FIGS. 21A to 21D illustrate variants of shapes for the
positioning rods. Shapes in a straight line, curved, elbowed or
double elbowed, etc. These are only examples of an almost unlimited
type of shapes that can be used without departing from the spirit
of the invention.
[0151] FIGS. 22A and 22F illustrate examples of different shapes of
rails that can be used to provide the sliding movement of the
positioning means: rectangular, dovetail, etc. These are only
examples of an almost unlimited type of shapes that can be used
without departing from the spirit of the invention.
[0152] FIGS. 23A and 23B illustrate the contacting means 30 when
placed against the heart surface. Two elongated contacting arms 31
defining therebetween an arterial window 32 are provided. The two
arms are preferably substantially parallel and the slot defined by
their inner edge is used as an arterial window. That is to say that
the target artery TA will be aligned between these two arms when
the contacting means is adequately placed. The arms are shaped to
be capable to press against the heart surface HS immediately
surrounding the target artery. In this way, the target artery
becomes easily accessible for the surgery purpose. As a result, the
heart stabilizer locally prevents the heart from moving around the
target artery, allowing thus direct coronary bypass surgery on a
beating heart In areas where the arteries are incrusted in the
heart surface, the contacting arms provide a way to raise the
target artery through the arterial window, thereby increasing
access for the purpose of the surgery.
[0153] This aspect of the invention can be clearly seen in FIG.
23B. The target artery TA is engaged between the arms 31. The
surgeon can thus advantageously attach the Silastic.TM. wire SL to
the portions of the target artery that are upstream and downstream
of the grafting site. This provides a very efficient way of
restricting the blood flow. The surgeon can then cut the artery and
realize the grafting process. Attachment means 310 are preferably
provided on the non-contacting surface side in order to set the
Silastic.TM. wire in an optimum position. For example, slotted
walls can be provided on the contacting arms 31. These attachment
means 310 are spaced sufficiently apart on said contacting arms to
allow the grafting process. These attachment means can eventually
be adjustable, for example axially with regard to the arms and/or
angularly.
[0154] The angle of the attachment means 310 with respect to the
contact arm 31 can be determined to coincide with the angle of the
Silastic.TM. wire with respect to said arm as it wraps around the
target artery. Furthermore, the walls or the like are preferably
capable of being oriented so that the wire penetrates in a
substantially normal direction with regard to the walls plane, that
is to say a preferred angle .gamma. (see FIG. 30A) between 25 and
80 degrees.
[0155] FIGS. 30B to 30G illustrate variants provided with
attachment means 310 of different profiles and shapes, respectively
"slotted blade type", "dip type", "spring type", "slotted
hemisphere type", "hanger type", and "plate-like type". These
examples clearly illustrate that the Silastic.TM., silicone rubber,
siliconized rubber, silicone elastomer or elastic wire (or other
type of wire) can be attached by a plurality of attachment means
types.
[0156] In order to facilitate the surgery, it is preferable to
first set the contacting means against the heart source in the
required position to free the target artery and secondly to secure
the contacting means and positioning means assembly to the sternum
retractor. To remove the assembly, it is preferable to first
disengage the contacting means from the positioning means, thereby
easing the separation of the containing means from the heart
surface and minimizing the risk of damage to the newly sutured
bypass vessel. Otherwise, the positioning means could also be
disengaged first form the retractor, to allow easy separation of
the contacting means from the heart surface. In all embodiments,
open ended articulation means and/or clamps for the second
positioning and help achieve this quickly and effectively (see FIG.
16).
[0157] The profile characteristics of the contacting means are very
important. For example, as shown in FIG. 23B, the ending portion of
the arms 31 is preferably curved. The arms are advantageously
provided with a ski-like shape with the tip portion oriented to be
away from the heart surface to prevent damage during involuntary
contact, avoiding trauma to the heart surface.
[0158] FIGS. 24 and 25 illustrate two "families" of contacting
means. These families originate from the position of the contacting
means with regard to the heart during the surgery and/or the type
of force resulting from this position. FIG. 24 shows a "push type"
arrangement, whereas FIG. 25 shows a "pull type" arrangement. From
these figures, it can easily be seen that the positioning means
plus contacting means assembly provides respectively a pushing
force (see also FIGS. 23A and 23B) and a pulling force (see also
FIG. 6). The "push type" and "pull type" are preferred for use with
the anterior and posterior arteries respectively. In all
embodiments, the motion degrees of freedom of the second
articulation means provide the adaptability to cater for push and
pull arrangements in a manner to maximize ergonomics of surgery
(FIGS. 24 and 25).
[0159] The contacting means profile is preferably adapted in
function of these two families. FIGS. 26, 27 and 28 show examples
of "push type" profiles. The attachment means 310 are then provided
on the upper portion of the alms 31. The illustrated example in
FIG. 26 is advantageously of oval shape. This facilitates the
access to certain arteries that would otherwise be difficult to
read.
[0160] Many other profiles are advantageously provided, each one of
them matching with a specific area of the heart FIGS. 27 and 28
illustrate further examples with spoon-like profiles: FIG. 27 with
standard spoon configuration (convex contact) and FIG. 28 with
concave contact. Adapted profiles are pile for maximum surface
coverage, thereby minimizing heart trauma. Moreover, the interface
surface with the beating heart is optimized to maximize stability
while minimizing risk of damage to the heart.
[0161] FIGS. 29A and 29B show a variant of "pull type" arrangement,
in which a given angle is provided between the positioning rod and
the contacting means.
[0162] FIGS. 31A to 31F show variants of the contacting means with
textured sits favoring adherence between the arms 31 and the heart
surface, to ensure minimum slip with regard to the heart tissue for
example caused by the heart pulsation. Various types of textures
can be provided, like for example, (from FIGS. 31A to 31F
respectively) with grooves, with dimples/pedestals, with holes,
with perimeter fence, with jagged outer contour, with covalently
banded surface treatment, etc. This helps to prevent "skidding" or
"slipping" on either side of target artery during grafting. The
contacting means are provided to be in relation with the cardiac
organs, in particular the heart The terms "cardiac organs" comprise
the heart, but also the surrounding vessels and tissues, in
particular the mediastinum, the pericardium, the thymus, the area
between two lungs, etc.
[0163] To simplify the surgeon's task and to free the cavity for
better ergonomics, the positioning rods may also provide different
features, like holes or grooves, or the like.
[0164] FIG. 32 illustrates an example in which grooves and holes
are used as anchoring points. Those features can also be used with
Silastic.TM. wire, suturing wire, suturing silk, silicon loops or
the like inserted through said holes and/or said grooves, and
attached to anchoring me on the sternum rear to brace and noggin
the assembly as rigidly as possible.
[0165] The different parts and components of the present invention
can be manufactured from either a biocompatible plastic, for
example medical grade ABS, for single use, or in surgical stainless
steel or any other biocompabble sterilizable material to allow for
repeat usage.
[0166] The above description of the preferred embodiments should
not be interpreted in any limiting manner since variations and
refinements are possible without departing from the spirit of the
invention.
* * * * *