Access platform for internal mammary dissection

What is claimed is:

1. An access platform comprising

a spreader member,

an inferior blade,

an inferior blade arm connected to said spreader member and said inferior blade,

a superior blade,

a superior blade arm connected to said superior blade and pivotally coupled to said spreader member at a pivot positioned above said superior blade, said superior blade being freely upwardly rotatable as a spreading force from said inferior blade is transmitted to said superior blade through said pivot.

2. The access platform of claim 1 further comprising

a sternal pad, and

a sternal pad arm attached to said sternal pad at a first end and rotatably coupled to said superior blade arm adjacent said pivot at a second end.

3. The access platform of claim 2 further comprising

a ratchet formed on said superior blade arm adjacent said pivot, and

a pawl pivotally mounted on said sternal pad arm and operably coupled to said ratchet.

4. The access platform of claim 3 further comprising

a drive block operably coupled to said spreader member, and

a cylindrical shaft extending from said drive block, said superior blade arm and said sternal pad arm being rotatably and releasably mounted on said shaft.

5. The access platform of claim 1 further comprising

a compression shoe, and

a shoe arm attached to said compression shoe at a first end and rotatably coupled at a second end to said superior blade arm adjacent said pivot.

6. The access platform of claim 5 further comprising

a pinion housing operably coupled to said spreader member and having a moveable pivot extending therefrom,

a cylindrical stem extending from said superior blade arm, said stem being rotatably received in said moveable pivot, and said sternal pad arm being rotatably mounted on said stem.

7. The access platform of claim 6 further comprising a moveable pivot lock mounted on said shoe arm and operably connected to said stem.

8. The access platform of claim 7 further comprising a vertical displacement member connected to said spreader member and operably interconnected to said compression shoe and said shoe arm.

9. The access platform of claim 8 further comprising

an offset link attached to said spreader member, and

an adjustable offset drive screw operably connected to said offset link and said shoe arm.

10. The access platform of claim 9 further comprising

first and second spaced apart fingers formed in an end of said offset link opposite said spreader member, and

a bushing rotatably captured by and extending between said first and second fingers.

11. The access platform of claim 10 further comprising a boss extending from said shoe arm, said boss having a recess adapted to receive a hemispherical end of said adjustable offset drive screw.

12. The access platform of claim 1 wherein said spreader member comprises

a drive base, said inferior blade arm extending from said drive base,

a drive shaft operably coupled to said drive base, said superior blade arm being pivotally interconnected and operably coupled to said drive shaft, and

a first handle attached to a first end of said drive shaft.

13. The access platform of claim 12 further comprising

a second handle rotatably coupled to said drive base and threadably connected to said drive shaft, and

a carrier threadably connected to said drive shaft and translatably connected to said drive base and said drive shaft, said carrier and said second handle having oppositely wound threads, and said superior blade arm being pivotally interconnected to said carrier.

14. The access platform of claim 13 further comprising

a carrier arm extending upwardly and outwardly from said carrier,

a branch extending from said superior blade arm, said branch being pivotally captured by said carrier arm at said pivot positioned above said superior blade, and

a tab extending downwardly from said branch of said superior blade arm and operably contacting a second end of said drive shaft extending beyond said carrier.

15. The access platform of claim 14 further comprising

a sternal pad, and

a sternal pad arm extending from said drive base and connecting to said sternal pad.

16. The access platform of claim 15 further comprising

a bearing support extending upwardly from said drive base, and

a bearing coupled to said bearing support, said second handle being rotatably coupled to said bearing, said drive shaft being slidably received through said bearing and said bearing support.

17. The access platform of claim 16 wherein said bearing support, drive base, inferior blade, inferior blade arm, sternal pad and sternal pad arm are formed from one-piece construction.

18. The access platform of claim 1 further comprising

a sternal pad,

a sternal pad arm extending from said spreader member and connecting to said sternal pad.

19. The access platform of claim 18 further comprising

an offset stanchion extending upwardly from said sternal pad arm, said superior blade arm being pivotally mounted to said offset stanchion at said pivot located above said superior blade,

a compression member extending from said offset stanchion,

a counter-lift tab extending from said superior blade arm adjacent said offset stanchion in spaced relation with said compression member, and

an offset spring interposing and operably coupling to said compression member and said counter-lift tab.

20. The access platform of claim 19 wherein said inferior blade arm is translatably coupled to said spreader member.

21. The access platform of claim 20 wherein said compression member is pivotally connected to said offset stanchion and adjustably interconnected to said spreader member.

22. The access platform of claim 21 further comprising an offset lead screw threadably connected to said compression member and rotatably interconnected to said spreader member.

23. The access platform of claim 1 further comprising a tissue retractor mounted to said superior blade.

24. The access platform of claim 23 wherein said tissue retractor comprises a plurality of interconnected fingers.

25. The access platform of claim 24 further comprising a positioner mounted to said superior blade and rotatably coupled to said plurality of interconnected fingers, said plurality of interconnected fingers being freely rotatable in a first direction and prevented from rotating in a second direction by said positioner.

26. The access platform of claim 25 wherein said positioner comprises

an elongated base mounted to said superior blade,

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.

27. The access platform of claim 26, wherein said positioner further comprises a flexure interconnecting said guide to said brake.

28. The access platform of claim 27, wherein said guide comprises a central portion integrally formed with said base and outer portions formed in a spaced relation with said base, and said positioner further comprises a tab extending upwardly from said brake adjacent said central portion of said guide.

29. The access platform of claim 28, 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.

30. The access platform of claim 24 wherein said tissue retractor comprises

a retractor arm rotatably coupled at a first end to said superior blade arm,

a spindle extending outwardly from a second end of said retractor arm, and

an elastic sheet attached to and extending between said spindle and said second blade.

31. The access platform of claim 1 wherein said spreader member includes a block and tackle drive mechanism.

32. The access platform of claim 31 wherein said block and tackle mechanism includes a clutch.

33. The access platform of claim 32 wherein said clutch comprises

a clutch housing,

a cylindrical capstand rotatably mounted in said clutch housing, and

a hub releasably coupled to and coaxially mounted within said capstand.

34. The access platform of claim 33 wherein said clutch further comprises

first and second dowel pins extending longitudinally along the exterior of said hub, said first and second dowel pins being partially captured in first and second recesses along the interior of said capstand, and partially captured within a slot bored through said hub, and

a spring mechanism positioned within said slot of said hub and interposed between said first and second dowel pins, said spring mechanism biasing said dowel pins outwardly into said first and second recesses of said capstand.

35. The access platform of claim 1 wherein the spreader member further comprises

a gear driven lead screw having first and second portions with oppositely wound threads thereon, and

first and second drive blocks operably interconnected to said first and second portions of said gear driven lead screw and said inferior and superior blade arms.

36. The access platform of claim 1 wherein said spreader member comprises

a spreader base,

an harmonic gear drive mounted in said spreader base,

first and second spreader arms coupled to said harmonic gear drive,

first and second blade arm mounts pivotally coupled to said inferior and superior blade arms,

first and second spreader links pivotally coupled to said first and second spreader arms and first and second blade arm mounts, respectively, and

first and second guide links pivotally connected to said first and second blade arm mounts and said spreader base.

37. The access platform of claim 1 wherein said spreader member comprises

a lead screw,

a carrier threadably mounted on said lead screw, and

a plurality of links pivotally connected to said carrier and said inferior and superior blade arms.

38. The access platform of claim 1 wherein said superior blade is convertible from a spreader type blade to a lifting type blade.

39. The access platform of claim 38 wherein said superior blade further comprises a slot formed therein, and an elongated vane member foldably received within said slot.

40. The access platform of claim 38 wherein said superior blade comprises

a slot formed therein, and

a flexible and extensible elongated vane member slidably received within said slot.

41. The access platform of claim 40, wherein said extensible flexible vane member is flexible in a first direction and comprises a restraint to prevent flexing in a second direction.

42. The access platform of claim 38 wherein said superior blade comprises

a spreader blade member having a groove formed in its upper portion and a tongue extending from its lower portion, and

an offset blade member detachably coupled to said spreader blade member, said offset blade member comprising a throat section having a recess formed therein, a tongue extending from an upper portion of said recess to mate with said groove of said spreader blade member, a groove formed in the lower portion of said recess to mate with said tongue of said spreader blade member, and an elongated vane portion extending out from the throat section.

43. The access platform of claim 1 wherein said superior blade includes a forced tapering flexible edge extending from and coupled to one end of said superior blade via a tongue and groove type connector.

44. The access platform of claim 1 wherein said superior blade comprises a tissue retractor formed integrally therewith.

45. The access platform of claim 1 wherein said superior blade comprises a plurality of access mounts formed on the back side of said superior blade.

46. The access platform of claim 45 wherein a heart stabilizer is mounted in one of said plurality of access mounts.

47. The access platform of claim 45 wherein a malleable shaft blower is mounted in one of said plurality of access mounts.

48. The access platform of claim 45 wherein a flexible blower and hose is coupled to one of said plurality of access mounts.

49. The access platform of claim 45 wherein a suction boot is mounted in one of said plurality of access mounts.

50. The access platform of claim 45 wherein a surgical clip is mounted in one of said plurality of access mounts.

51. The access platform of claim 45 wherein a light source is mounted in one of said plurality of access mounts.

52. The access platform of claim 1 further comprising

a surgical clip,

a mount coupled to said superior blade arm, and

a stem extending from said mount and connecting to said surgical clip.

53. The access platform of claim 52 further comprising an intermediate mounting block interposed between said mount and said superior blade arm, and coupled to said superior blade arm.

54. The access platform of claim 53 wherein said intermediate mounting block comprises input ports providing is access to sources of suction, aeration and electrical power.

55. The access platform of claim 53 wherein said intermediate mounting block further comprises output lumens to interconnect surgical tools to sources of suction, aeration and electrical power interconnected to said input ports.

56. The access platform of claim 1 further comprising

a light panel electrically coupled to a light source and mounted to said superior blade and said superior blade arm.

57. The access platform of claim 56 wherein said light panel comprises a light directing contoured surface.

58. The access platform of claim 1 wherein said superior blade arm comprises a universal port providing access to sources of electrical power, aeration and suction.

59. The access platform of claim 58 wherein said superior blade arm further comprises an on/off switch coupled to said universal port.

60. The access platform of claim 59 wherein said on/off switch operably locks a universal connector in an engaged position with said universal port.

61. The access platform of claim 1 wherein said superior blade comprises

an embedded electrical source extending along the back side of said superior blade,

a first dovetail slot extending along the backside of said superior blade,

a slide slidably received in said first dovetail slot, said slide comprising a second dovetail slot formed therein, and

a connector received in said second dovetail slot, said connector including a push button that electrically couples a surgical tool to said embedded electrical source.

62. The access platform of claim 1 further comprising a suture holder coupled to said inferior and superior blade arms, said suture holder surrounding an access area between said inferior and superior blades when said inferior and superior blades are positioned within an incision in a patient's chest.

63. The access platform of claim 62 wherein said suture holder is constructed from felt.

64. The access platform of claim 62 wherein the suture holder is constructed from foam.

65. The access platform of claim 62 wherein the suture holder is constructed from rubber.

66. A self-aligning access platform comprising

first and second blades,

a first blade arm connected to said first blade,

a second blade arm operably coupled to said first blade arm, and

a flexure interconnecting said second blade to said second blade arm.

67. The self-aligning access platform of claim 66, further comprising first and second flexures forming a "V"-shaped blade mount interconnecting said second blade arm to said second blade.

68. The self-aligning access platform of claim 66, further comprising a tension member connected to said second blade at a second flexure and interconnected to said second blade arm.

69. A bladeless access platform comprising

a tubular body having top and bottom edges, and

a pair of elongated handles extending upwardly from the top of said tubular body.

70. The bladeless access platform of claim 69 wherein said tubular body comprises sidewalls that are concave in shape.

71. A bladeless access platform comprising

a hollow conically shaped body having a first tip portion releasably coupled to a second portion, and

a plurality of threads formed on the exterior of said conically shaped body.

72. The bladeless access platform of claim 71, wherein said conically shaped body further comprises a third portion releasably coupled to said second portion.

73. The bladeless access platform of claim 72, further comprising splined connections that interconnect said second portion to said first tip portion and said third portion.

74. The bladeless access platform of claim 72, further comprising locking tabs positioned within locking grooves formed within said second and third portions.

75. The bladeless access platform of claim 72, further comprising finger or drive tool pockets formed in the interior of said first tip, second and third portions.

76. An access platform comprising

first and second blades, and

an offset spreader assembly including a handle pivotally mounted at one of its ends to said first blade and at a midpoint to said second blade to spread and raise the second blade relative to the first blade in one motion, and

a guide link pivotally connected to said first and second blades.

77. The access platform of claim 76 wherein said handle of said offset spreader is "U"-shaped and is pivotally connected to said first and second blades adjacent opposing ends of said first and second blades, and a second guide link pivotally connected to said first and second blades.

78. The access platform of claim 76, further comprising

a first blade mount extending upwardly from said first blade and a second mount extending downwardly from said second blade, said first blade mount being pivotally mounted to said handle at a midpoint of said handle and said second blade mount being pivotally mounted to said handle at one of its end, and said guide link being pivotally mounted to said first and second blade mounts.

79. The access platform of claim 78, wherein said offset spreader assembly is releasably mounted to said first and second blades and further comprises

a dovetail assembly comprising first and second tails formed in said first and second blade mounts, and

first and second pins extending from said first and second blades to mate with said first and second tails.

80. The access platform of claim 79, further comprising an offset positioner assembly releasably coupled to said first and second blades.

81. The access platform of claim 80, wherein said offset positioner assembly further comprises

first and second position mounts formed on said first and second blades,

a positioning arm releasably coupled to said first and second position mounts, and

a sternal pad and arm rotatably coupled to said positioning arm.

82. The access platform of claim 81, further comprising a pawl pivotally coupled to said sternal pad arm and operably connected to a ratchet which is interconnected to said positioning arm.

83. The access platform of claim 82, wherein said positioning arm further comprises first and second splined shafts extending from said positioner arm adjacent first and second ends of said positioning arm, said splined shafts being received in and discreetly coupled to first and second splined holes formed in said first and second position mounts on first and second blades.

84. A method for dissecting an internal mammary artery comprising the steps of

positioning a superior blade, superior blade arm, sternal pad arm and sternal pad of an access platform on the patient's chest, the superior blade arm extends from the superior blade and is rotatably coupled to the sternal pad arm which extends from the sternal pad,

inserting the superior blade into an incision in the patient's chest wall,

sliding the superior blade under the superior ribs adjacent to the incision,

adjusting the sternal pad downwardly to the patient's chest by rotating the pad arm relative to the superior blade arm,

aligning an inferior blade and spreader member of the access platform on the patient's chest, the inferior blade being coupled to the spreader member,

inserting the inferior blade into the incision in the patient's chest,

coupling the superior blade, superior blade arm, sternal pad and sternal pad arm rotatably to the spreader member of the access platform at a pivot point above the superior blade,

spreading apart the inferior and superior blades and corresponding ribs,

transmitting a spreading force from the inferior blade to the superior blade through the pivot located above the superior blade at a position where the superior blade, superior blade arm, sternal pad and sternal pad arm are rotatably coupled to said spreader member,

rotating said superior blade upwardly around the pivot to offset the superior ribs, and

dissecting the IMA.

85. The method of claim 84 further comprising the steps of

connecting a vertical displacement member to the spreader member and the sternal pad arm, and

adjusting the vertical displacement member to further offset the superior ribs once said inferior and superior blades are separated.

86. The method of claim 84 further comprising the steps of

sterilizing the access platform, and

packaging the access platform in a sterile package.

87. The method of claim 84 further comprising the steps of inhibiting the upward rotation of the superior blade by applying a spring force to a counterlift tab attached to the superior blade arm.

Description Submit all comments and votes

DESCRIPTION

1. Field of the Invention

This invention relates to retractors, and more particularly to an access platform that facilitates access to the interior of the chest cavity during surgical procedures.

2. Background of the Invention

Diseases of the cardiovascular system affect millions of people each year and are a leading cause of death in the United States and throughout the world. The cost to society from such diseases is enormous both in terms of lives lost and the cost of treating cardiac disease patients through surgery. A particularly prevalent form of cardiovascular disease is a reduction in the blood supply to the heart caused by atherosclerosis or other conditions that create a restriction in blood flow at a critical point in the cardiovascular system leading to the heart. In many cases, a blockage or restriction in the blood flow leading to the heart can be treated by a surgical procedure known as a Coronary Artery Bypass Graft (CABG) procedure, which is more commonly known as a "heart bypass" operation. In the CABG procedure, the surgeon either removes a portion of a vein from another part of the body to use as a graft and installs the graft at points that bypass the obstruction to restore normal blood flow to the heart or detaches one end of an artery and connects that end past the obstruction while leaving the other end attached to the arterial supply to restore normal blood flow to the heart.

Although the CABG procedure has become relatively common, i.e., heart bypass surgery is performed in one of every thousand persons in the United States, the procedure is lengthy and traumatic and can damage the heart, the central nervous system, and the blood supply. In a conventional CABG procedure, the surgeon cuts off the blood flow to the heart and then stops the heart from beating in order to install the graft. Thus, in order to perform the conventional CABG procedure, the surgeon must make a long incision down the middle of the chest, saw through the entire length of the sternum, spread the two halves of the sternum apart, and then perform several procedures necessary to attach the patient to a cardiopulmonary bypass machine to 93 continue the circulation of oxygenated blood to the rest of the body while the graft is sewn in place.

The CABG procedure further requires that a connection for the flow of blood be established between two points that "by pass" a diseased area and restore an adequate blood flow. Typically, one end of a graft is sewn to the aorta, while the other end of the graft is sewn to a coronary artery, such as the left anterior descending (LAD) artery that provides blood flow to the main muscles of the heart. This procedure is known as a "free bypass graft." Alternatively, the IMA pedicle is dissected off of the chest wall, while still attached to its arterial supply, and attached to the LAD past the obstruction. This procedure is known as an "in situ bypass graft."

In an in situ bypass graft, the IMA must be dissected from its connective tissue until there is sufficient slack in the IMA to insure that the graft does not kink after it is installed. The IMAs, left and right, extend from the subclavian arteries in the neck to the diaphragm and run along the backside of the rib cage adjacent the sternum. During a conventional in situ bypass graft, typically the left half of the sternum is raised to increase the surgeon's access to the left IMA (LIMA) and the heart. A device used for this type of sternal retraction is disclosed in United Kingdom Patent Application No. GB 2267827 A, "A device for Internal Mammary artery dissection."

Although several efforts have been made to make the CABG procedure less invasive and less traumatic, most techniques still require cardiac bypass and cardioplegia (stoppage of the heart). The safety and efficacy of CABG procedure could be improved if the surgeon could avoid the need to stop the heart from beating during the procedure, thereby eliminating the need to connect the patient to a cardiopulmonary bypass machine to sustain the patient's life during the CABG procedure and, thus, eliminate the need for the lengthy and traumatic surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine. In recent years, a small number of surgeons have begun performing CABG procedures using surgical techniques especially developed to enable surgeons to perform the CABG procedure while the heart is still beating. In such procedures, there is no need for any form of cardiopulmonary bypass, no need to perform the extensive surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine, cardioplegia is rendered unnecessary, the surgery is much less invasive and traumatic, and the entire procedure can typically be achieved through one or two comparatively small incisions (thoracotomies) in the chest.

Despite these advantages, the beating-heart CABG procedure is not widely practiced, in part, because of the difficulty in performing the necessary surgical procedures with conventional instruments while the heart is still beating. If specially designed instruments were available so that the CABG procedure could more easily be performed on the beating heart, the beating-heart CABG procedure would be more widely practiced and the treatment of cardiovascular disease would be improved in a significant part of the cardiovascular disease patient population.

Since the "beating-heart" CABG procedure is performed while the heart muscle is continuing to beat or contract, an anastomosis is difficult to perform because the blood continues to flow and the heart continues to move while the surgeon is attempting to sew the graft in place. The surgical procedure necessary to install the graft requires placing a series of sutures through several extremely small vessels that continue to move during the procedure. The sutures must become fully placed so that the graft is firmly in place and does not leak. It is also important that the procedure be performed rapidly because the blood flow through the artery may be interrupted or reduced during the procedure to allow the graft to be installed. This can cause ischemia, which should be minimized. Also, the surgeon's working space and visual access are limited because the surgeon may be working through a small incision in the chest or may be viewing the procedure on a video monitor, such that the site of the surgery is viewed via a surgical scope.

The "beating-heart" CABG procedure could be greatly improved if the surgeon's working space and visual access to the heart and the IMA were increased and improved. Current methods to increase and improve the surgeon's working space and visual access include laterally spreading or retracting the ribs with a conventional rib spreader/retractor, and then vertically displacing one of the retracted ribs relative to the other retracted rib to create a "tunnel" under the rib cage. To vertically displace one of the retracted ribs, some force external to the rib spreader must be applied to the rib. Typically, a surgeon's assistant will push or pull upwardly on the rib with a device having a rib blade inserted under the rib. However, the surgeon's assistant must then hold the rib in a vertically displaced position for the duration of the IMA dissection, resulting in an undesirable addition of another set of hands around the surgical area.

Another method used by surgeons to vertically displace the retracted rib is to insert a rib blade under the retracted rib and then attach the rib blade to a winch located above the patient. The winch is then operated to pull upwardly on the rib and hold it in a vertically displaced position. However, it is not at all uncommon for the patient to be raised off the operating table by the winch. This is undesirable because if the rib begins to crack or break, the weight of the patient's body will cause the rib to continue to break until the patient reaches the operating table.

While using these methods to vertically displace one of the retracted ribs, it may be desirable to further increase a surgeon's working space and visual access by depressing the sternum or the other retracted rib. However, depression of the sternum or the other retracted rib undesirably adds further sets of hands around the surgical site.

Furthermore, these methods and devices tend to limit where the thoracotomy can be performed. For example, if the thoracotomy is performed on the lateral side of the chest, the conventional rib spreader would tend to "stand-up" vertically from the ribs it is retracting such that it would intrude on the surgeon's working space. In addition, if a winch is used to offset the ribs, the lifting action of the winch will tend to rotate the patient to an undesirable and often unstable position for performing the IMA.

Equally important to improving the "beating heart" CABG procedure, is the ability to retract the soft tissue around the incision in the chest to draw the soft tissue away from the surgeon's working area. However, none of the methods or devices described above provide the ability to perform soft tissue retraction.

Thus, in view of the shortcomings of these devices and methods for increasing a surgeon's working space and visual access during a "beating-heart" CABG procedure, it would be desirable to have a device that is capable of laterally spreading the ribs and vertically displacing opposing retracted ribs relative to each other, that is capable of depressing the sternum, that is self-contained such that the force necessary to spread and vertically displace the ribs, and the force necessary to depress the sternum, is applied by the access platform itself rather than through additional external devices, that does not limit the location where a thoracotomy can be performed, and that is capable of soft tissue retraction.

SUMMARY OF THE INVENTION

The access platform of the present invention serves to facilitate the dissection of an internal mammary artery (IMA), including both proximal and distal dissection, and access to the heart during a "beating heart" Coronary Artery Bypass Graft (CABG) procedure by increasing the surgeon's working space and visual access. The access platform of the present invention is preferably capable of laterally spreading the ribs, vertically displacing the opposingly retracted ribs relative to each other and depressing the sternum to cause a "tunnel" effect under the retracted ribs. Moreover, it is preferably self-contained such that the force necessary to spread and vertically displace the ribs is applied by the access platform itself rather than through additional external devices. The access platform preferably comprises 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.

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.

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.

In further embodiments, bladeless embodiments comprising tubular or hollow conically shaped bodies provide access to a patient's chest cavity.

It is an object of the present invention to provide an improved access platform.

Another object of the present invention is to provide an improved tissue retractor.

Further objects and advantages of the present invention will become apparent from a consideration of the drawings and the ensuing description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of an embodiment of an access platform of the present invention disposed over the chest of a patient.

FIG. 2 is an isometric view of the access platform shown in FIG. 1 less the tissue retractor elements.

FIG. 3 is an exploded isometric view of a harmonic gear drive assembly of the access platform in FIG. 1.

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.

FIG. 5 is an isometric view of a blade, a blade arm and a tissue retractor assembly for an access platform.

FIG. 6 is a front view of the access platform with the tissue retractors disengaged.

FIG. 7 is a front view of the access platform with the tissue retractors engaged.

FIG. 8 is a partial isometric view of a tissue retractor and blades assembly for an access platform.

FIG. 9 is an isometric view of a tissue retractor assembly for an access platform.

FIG. 10 is a side view of the tissue retractor assembly shown in FIG. 7 and including a positioning assembly.

FIG. 11 is an isometric view of the tissue retractor and positioning assembly in FIG. 8.

FIG. 12 is a partial side detail view of the positioning assembly in FIG. 8.

FIG. 13 is a top view of a second embodiment of the access platform of the present invention.

FIG. 14 is a partial front view of the access platform in FIG. 13.

FIG. 15 is a side view of the access platform as viewed along a line 15--15 in FIG. 13.

FIG. 16 is a front view of a third embodiment of the access platform of the present invention.

FIG. 17 is a front view of the access platform shown in FIG. 16 with a vertical displacement member engaged.

FIG. 18 is an isometric view of a fourth embodiment of the access platform of the present invention.

FIG. 19 is an isometric view of a fifth embodiment of the access platform of the present invention.

FIG. 20 is an elevation view of a pry bar for engaging the blade and blade arm of the access platform in FIG. 18.

FIG. 21 is a top view of the pry bar in FIG. 20.

FIG. 22 is an isometric view of a sixth embodiment of the access platform of the present invention.

FIG. 23 is an isometric view of a seventh embodiment of the access platform of the present invention.

FIG. 24 is a top view of an eighth embodiment of the is access platform of the present invention.

FIG. 25 is a rear view of the access platform in FIG. 24.

FIG. 26 is an isometric view of a ninth embodiment of the access platform of the present invention.

FIG. 27 is a front elevation view of a tenth embodiment of the access platform of the present invention.

FIG. 28 is an isometric view of an eleventh embodiment of the access platform of the present invention.

FIG. 29 is an isometric view of a twelfth embodiment of the access platform of the present invention.

FIG. 30 is an isometric view of a thirteenth embodiment of the access platform of the present invention.

FIG. 31 is a top view of a fourteenth embodiment of the access platform of the present invention.

FIG. 32 is a partial front elevation view of the access platform in FIG. 31.

FIG. 33 is an isometric view of a fifteenth embodiment of the access platform of the present invention.

FIG. 34 is a partial front elevation view of the access platform in FIG. 33.

FIG. 35 is a top view of a spreader member drive assembly of the access platform in FIG. 33.

FIG. 36 is an isometric view of a clutch assembly of the drive assembly in FIG. 35.

FIG. 37 is a partial cross-sectional view of the clutch assembly in FIG. 36.

FIG. 38 is a partial top schematic of the clutch assembly in FIG. 36.

FIG. 39 is an isometric view of an sixteenth embodiment of the access platform of the present invention.

FIG. 40 is an isometric view of a seventeenth embodiment of the access platform of the present invention.

FIG. 41 is an isometric view of a eighteenth embodiment of the access platform of the present invention.

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.

FIG. 43 is a front elevation view of the access platform in FIG. 41 in an open mode positioned between a patient's ribs.

FIG. 44 is an isometric view of a removable offset spreader assembly utilized with the access platform in FIG. 41.

FIG. 45 is an isometric view of an offset positioning assembly utilized with the access platform in FIG. 41.

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.

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.

FIG. 48 is an isometric view of a nineteenth embodiment of an access platform of the present invention.

FIG. 49 is an isometric view of a twentieth embodiment of the access platform of the present invention positioned between a patient's ribs.

FIG. 50 is a partial sectional isometric view of the access platform in FIG. 49.

FIG. 51 is an isometric view of the access platform in FIG. 49 rotated to access the IMA.

FIG. 52 is a partial sectional isometric view of the access platform in FIG. 51.

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.

FIG. 54 is an elevation view of the access platform in FIG. 53 in an intermediately engaged position.

FIG. 55 is an isometric view of the access platform in FIG. 53 in a final engaged position.

FIG. 56 is a top view of a locking assembly of the access platform in FIG. 53.

FIG. 57 is an isometric view of a spreader member drive assembly.

FIG. 58 is a partial detail elevation view of a drive gear assembly for the drive assembly in FIG. 57.

FIG. 59 is a partial detail elevation view of a drive gear assembly for the drive assembly shown in FIG. 57.

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.

FIG. 61 is a top view of the access platform in FIG. 60 incorporating an alternate spreader member drive assembly.

FIG. 62 is a top view of a spreader member drive assembly for an access platform.

FIG. 63 is a top view of a spreader member drive assembly for an access platform.

FIG. 64 is a top view of a spreader member drive assembly for an access platform.

FIG. 65 is a top view of a spreader member drive assembly for an access platform.

FIG. 66 is a top view of a self-aligning blade embodiment of the access platform of the present invention in a disengaged position.

FIG. 67 is a top view of the access platform in FIG. 66 in an engaged position.

FIG. 68 is a partial isometric view of a blade and blade arm assembly of the access platform in FIG. 66.

FIG. 69 is a top view of opposing self-aligning blade and blade arm assemblies.

FIG. 70 is a partial isometric view of one of the self-aligning blade and blade arm assemblies in FIG. 69.

FIG. 71 is an isometric view of a spreader blade with a foldable vane for offset.

FIG. 72 is an isometric view of a spreader blade with a extensible vane for offset or tissue retraction.

FIG. 73 is an elevation view of a spreader blade and detachable offset blade assembly.

FIG. 74 is an elevation view of the spreader blade and vane assembly in FIG. 73 in a disengaged position.

FIG. 75 is an isometric view of a retractor blade with detachable flexible edges.

FIG. 76 is an isometric view of a retractor blade with an integral tissue retractor.

FIG. 77 is an isometric view of a spreader blade with surgical tools mounted through access mounts formed integrally with the spreader blade.

FIG. 78 is an isometric view of a spreader blade with surgical tools mounted through access mounts formed integrally with the spreader blade.

FIG. 79 is a cross-sectional view of the spreader blade and flexible blower assembly in FIG. 77.

FIG. 80 is an isometric view of the access platform in FIG. 23 less the offsetting assembly and having a surgical clip mounted thereto.

FIG. 81 is an isometric exploded view of a surgical clip, mount and intermediate mounting block assembly.

FIG. 82 is an isometric view of the access platform in FIG. 35 having a mirror, a light source and clip assembly mounted thereto.

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.

FIG. 84 is a partial elevation view of a directional light source mounted to the bottom of a superior blade.

FIG. 85 is an isometric view of a spreader blade assembly.

FIG. 86 is an isometric view of a spreader blade assembly.

FIG. 87 is an isometric view of an access platform and suture holder assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT

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.

Turning to FIG. 1, the access platform 10 incorporating a preferred embodiment of the present invention, is shown disposed over the outline of a patient's chest P. An incision in the patient's chest P adjacent to the LIMA (shown in phantom) exposes an LAD artery on the exterior of the patient's heart. Preferably, the access platform 10 comprises a pair of blades 50 and 51, a pair of support pads 80 and 81, a pair of tissue retractors 70 and 71, a pair of torsional members 30 and 31, and a spreader member 12. The torsional members 30 and 31 and the spreader member 12 preferably extend away from the blades 50 and 51 and the tissue retractors 70 and 71 and, thus, the chest incision, in a plane relatively parallel to the patient's chest. As a result, the access platform 10 advantageously maintains a low profile that remains substantially clear of the surgeon's working space.

Referring to FIG. 2, the components of the access platform 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.

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.

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 a lead-screw mechanism or worm gear mechanism, are discussed in detail below.

Referring to FIG. 2, the blades 50 and 51 preferably include elongated vanes 52 and 53, which slide beneath a plurality of the patient's ribs, and recessed arcuate throats 54 and 55 that receive the patient's ribs that are adjacent to the chest incision. The benefits of the recessed throats 54 and 55 and the elongated vanes 52 and 53 will be discussed below with regard to the operation of the access platform 10.

Blade arms 56 and 57 interconnect the blades 50 and 51 to the rest of the access platform 10. The blade arms 56 and 57 comprise stems 62 and 63 received in sockets 34 and 35 in torque bases 32 and 33. The sockets 34 and 35 and the stems 62 and 63 are constructed such that the blade arms 56 and 57 are releasably connected to the torque bases 32 and 33. The stems 62 and 63, which extend relatively horizontally from the torque bases 32 and 33, include pivot sections 60 and 61 extending therefrom. Branches 58 and 59 extend outwardly and downwardly away from the pivot sections 60 and 61 and are attached to the throats 54 and 55 of the blades 50 and 51. This blade arm construction advantageously directs the bulk of the access platform 10 away from the surgeon's working area.

The support pads 80 and 81 are connected to adjustable arms 86 and 87 by swivel connectors 82 and 83 that are preferably constructed as ball and socket type connectors 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